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Lu J, Qing C, Huang X, Zeng J, Zheng Y, Xia P. Seasonal dynamics and driving mechanisms of microbial biogenic elements cycling function, assembly process, and co-occurrence network in plateau lake sediments. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 951:175510. [PMID: 39147055 DOI: 10.1016/j.scitotenv.2024.175510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2024] [Revised: 08/11/2024] [Accepted: 08/12/2024] [Indexed: 08/17/2024]
Abstract
Microbial community diversity significantly varies with seasonality. However, little is known about seasonal variation of microbial community functions in lake sediments and their associated environmental influences. In this study, metagenomic sequencing of sediments collected from winter, summer, and autumn from Caohai Lake, Guizhou Plateau, were used to evaluate the composition and function of sediment microbial communities, the potential interactions of functional genes, key genes associated with seasons, and community assembly mechanisms. The average concentrations of nitrogen (TN) and phosphorus (TP) in lake sediments were higher, which were 6.136 and 0.501 g/kg, respectively. TN and organic matter (OM) were the primary factors associated with sediment community composition and functional profiles. The diversity and structure of the microbial communities varied with seasons, and Proteobacteria relative abundances were significantly lower in summer than in other seasons (58.43-44.12 %). Seasons were also associated with the relative abundances of functional genes, and in particular korA, metF, narC, nrfA, pstC/S, and soxB genes. Network complexity was highest in the summer and key genes in the network also varied across seasons. Neutral community model analysis revealed that the assembly mechanisms related to carbon (C), nitrogen (N), phosphorus (P), and sulfur (S) cycle-related genes were primarily associated with random processes. In summary, diverse functional genes were identified in lake sediments and exhibited evidence for synergistic interactions (Positive proportion: 74.91-99.82 %), while seasonal factors influenced their distribution. The results of this study provide new insights into seasonal impacts on microbial-driven biogeochemical cycling in shallow lakes.
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Affiliation(s)
- Jiaowei Lu
- Key Laboratory for Information System of Mountainous Areas and Protection of Ecological Environment of Guizhou Province, Guizhou Normal University, Guiyang 550001, China
| | - Chun Qing
- Key Laboratory for Information System of Mountainous Areas and Protection of Ecological Environment of Guizhou Province, Guizhou Normal University, Guiyang 550001, China
| | - Xianfei Huang
- Key Laboratory for Information System of Mountainous Areas and Protection of Ecological Environment of Guizhou Province, Guizhou Normal University, Guiyang 550001, China
| | - Jin Zeng
- Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China
| | - Yikun Zheng
- Key Laboratory for Information System of Mountainous Areas and Protection of Ecological Environment of Guizhou Province, Guizhou Normal University, Guiyang 550001, China
| | - Pinhua Xia
- Key Laboratory for Information System of Mountainous Areas and Protection of Ecological Environment of Guizhou Province, Guizhou Normal University, Guiyang 550001, China.
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Kim HJ, Kim YJ, Kang D, Kim H, Cho S, Lee TK, Lee SH, Jung SW, Kang J. Co-occurrence between key HAB species and particle-attached bacteria and substrate specificity of attached bacteria in the coastal ecosystem. HARMFUL ALGAE 2024; 138:102700. [PMID: 39244235 DOI: 10.1016/j.hal.2024.102700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2024] [Revised: 07/16/2024] [Accepted: 07/17/2024] [Indexed: 09/09/2024]
Abstract
The ecological dynamics of particle-attached bacteria (PAB) were observed through changes in the core phytoplankton phycosphere, and were associated with the dynamics of free-living bacteria (FLB) using metabarcoding and microscopic analyses over 210 days (with weekly sampling intervals) in the Jangmok coastal ecosystem, South Korea. Cluster analysis and non-metric multidimensional scaling classified the phytoplankton community into six groups comprising core phytoplankton species, including the harmful algal species Akashiwo sanguinea (dinoflagellate) in late autumn, Teleaulax amphioxeia (cryptomonads) in early winter and spring, Skeletonema marinoi-dohrnii complex (diatom) in winter, Pseudo-nitzschia delicatissima (diatom) in early spring, and diatom complexes such as Chaetoceros curvisetus and Leptocylindrus danicus in late spring. We identified 59 and 32 indicators in PAB and FLB, respectively, which rapidly changed with the succession of the six core phytoplankton species. The characteristics of PAB were mainly divided into "Random encounters" or "Attraction of motivation by chemotaxis." When Akashiwo sanguinea bloomed, bacteria of the genera Kordiimonas and Polaribacter, which are commonly observed in PAB and FLB, indicated "Random encounter" characteristics. In addition, Sedimenticola of PAB was uniquely presented in Akashiwo sanguinea, exhibiting characteristics of "Attraction of motivation by chemotaxis." In contrast, FLB followed the strategy of "Random encounters" because it was not affected by specific habitats and energy sources. Thus, many common bacteria were PAB and FLB, thereby dictating the bacteria's strategy of "Random encounters." "Attraction of motivation by chemotaxis" has characteristics of the species-specific interactions between PAB and specific harmful algal species, and is potentially influenced by organic matter of core phytoplankton cell surface and/or EPS released from phytoplankton.
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Affiliation(s)
- Hyun-Jung Kim
- Library of Marine Samples, Korea Institute of Ocean Science & Technology, Geoje, 656-834, Republic of Korea; Department of Oceanography and Marine Research Institute, Pusan National University, Busan, 46241, Republic of Korea
| | - Yu Jin Kim
- Library of Marine Samples, Korea Institute of Ocean Science & Technology, Geoje, 656-834, Republic of Korea; Department of Ocean Science, University of Science and Technology, Daejeon, 34113, Republic of Korea
| | - Donhyug Kang
- Maritime Security and Safety Research Center, Korea Institute of Ocean Science & Technology, Busan, 49111, Republic of Korea
| | - Hansoo Kim
- Maritime Security and Safety Research Center, Korea Institute of Ocean Science & Technology, Busan, 49111, Republic of Korea
| | - Sungho Cho
- Maritime Security and Safety Research Center, Korea Institute of Ocean Science & Technology, Busan, 49111, Republic of Korea
| | - Taek-Kyun Lee
- Department of Ocean Science, University of Science and Technology, Daejeon, 34113, Republic of Korea; Ecological Risk Research Department, Korea Institute of Ocean Science & Technology, Geoje, 53201, Republic of Korea
| | - Sang Heon Lee
- Department of Oceanography and Marine Research Institute, Pusan National University, Busan, 46241, Republic of Korea
| | - Seung Won Jung
- Library of Marine Samples, Korea Institute of Ocean Science & Technology, Geoje, 656-834, Republic of Korea; Department of Ocean Science, University of Science and Technology, Daejeon, 34113, Republic of Korea.
| | - Junsu Kang
- Ballast Water Research Center, Korea Institute of Ocean Science & Technology, Geoje, 53201, Republic of Korea
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Cianciotto NP. The type II secretion system as an underappreciated and understudied mediator of interbacterial antagonism. Infect Immun 2024; 92:e0020724. [PMID: 38980047 PMCID: PMC11320942 DOI: 10.1128/iai.00207-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/10/2024] Open
Abstract
Interbacterial antagonism involves all major phyla, occurs across the full range of ecological niches, and has great significance for the environment, clinical arena, and agricultural and industrial sectors. Though the earliest insight into interbacterial antagonism traces back to the discovery of antibiotics, a paradigm shift happened when it was learned that protein secretion systems (e.g., types VI and IV secretion systems) deliver toxic "effectors" against competitors. However, a link between interbacterial antagonism and the Gram-negative type II secretion system (T2SS), which exists in many pathogens and environmental species, is not evident in prior reviews on bacterial competition or T2SS function. A current examination of the literature revealed four examples of a T2SS or one of its known substrates having a bactericidal activity against a Gram-positive target or another Gram-negative. When further studied, the T2SS effectors proved to be peptidases that target the peptidoglycan of the competitor. There are also reports of various bacteriolytic enzymes occurring in the culture supernatants of some other Gram-negative species, and a link between these bactericidal activities and T2SS is suggested. Thus, a T2SS can be a mediator of interbacterial antagonism, and it is possible that many T2SSs have antibacterial outputs. Yet, at present, the T2SS remains relatively understudied for its role in interbacterial competition. Arguably, there is a need to analyze the T2SSs of a broader range of species for their role in interbacterial antagonism. Such investigation offers, among other things, a possible pathway toward developing new antimicrobials for treating disease.
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Affiliation(s)
- Nicholas P. Cianciotto
- Department of Microbiology-Immunology, Northwestern University School of Medicine, Chicago, Illinois, USA
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4
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Shibulal B, Smith MP, Cooper I, Burgess HM, Moles N, Willows A. Deciphering microbial communities involved in marine steel corrosion using high-throughput amplicon sequencing. ENVIRONMENTAL MICROBIOLOGY REPORTS 2024; 16:e70001. [PMID: 39189590 PMCID: PMC11348066 DOI: 10.1111/1758-2229.70001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2024] [Accepted: 07/26/2024] [Indexed: 08/28/2024]
Abstract
To characterize the source and effects of bacterial communities on corrosion of intertidal structures, three different UK coastal sites were sampled for corrosion materials, sediment and seawater. Chemical analyses indicate the activity of sulfate-reducing microbes (SRBs) at 2 sites (Shoreham and Newhaven), but not at the third (Southend-on-Sea). Microbial communities in the deep sediment and corrosion samples are similar. The phylum Proteobacteria is dominant (40.4% of the total ASV), followed by Campilobacterota (11.3%), Desulfobacterota and Firmicutes (4%-5%). At lower taxonomic levels, corrosion causing bacteria, such as Shewanella sp. (6%), Colwellia sp. (7%) and Mariprofundus sp. (1%), are present. At Southend-on-sea, the relative abundance of Campilobacterota is higher compared to the other two sites. The mechanism of action of microorganisms at Shoreham and Newhaven involves biogenic sulfuric acid corrosion of iron by the combined action of SRBs and sulfur-oxidizing microbes. However, at Southend-on-sea, sulfur compounds are not implicated in corrosion, but SRBs and other electroactive microbes may play a role in which cathodic reactions (electrical MIC) and microbial enzymes (chemical MIC) are involved. To contribute to diagnosis of accelerated intertidal corrosion types, we developed a rapid identification method for SRBs using quantitative polymerase chain reaction high-resolution melt curve analysis of the dsrB gene.
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Affiliation(s)
- Biji Shibulal
- School of Applied SciencesUniversity of BrightonBrightonUK
| | | | - Ian Cooper
- School of Applied SciencesUniversity of BrightonBrightonUK
| | | | - Norman Moles
- School of Applied SciencesUniversity of BrightonBrightonUK
| | - Alison Willows
- School of Applied SciencesUniversity of BrightonBrightonUK
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5
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Hill LJ, Messias CSMDA, Vilela CLS, Garritano AN, Villela HDM, do Carmo FL, Thomas T, Peixoto RS. Bacteria associated with the in hospite Symbiodiniaceae's phycosphere. iScience 2024; 27:109531. [PMID: 38585661 PMCID: PMC10995889 DOI: 10.1016/j.isci.2024.109531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 12/23/2023] [Accepted: 03/16/2024] [Indexed: 04/09/2024] Open
Abstract
Symbiotic interactions between Symbiodiniaceae and bacteria are still poorly explored, especially those in hospite. Here, we adapted a technique that allows for the enrichment of intact and metabolically active in hospite Symbiodiniaceae cells (ihSC) and their associated bacteria from the tissue of the model coral Pocillopora damicornis, using a discontinuous gradient of solution of isotonic Percoll (SIP). The ihSC were concentrated in the 50% SIP fraction, as determined by microscopy. The presence of bacteria associated with ihSC was confirmed by fluorescence in situ hybridization, while microbiome analysis indicated that bacteria of the families Halieaceae, Flavobacteriaceae, and Alcanivoraceae are significantly associated with ihSC. Extracellular vesicles that could be exuding molecules were detected on the symbiosome membranes. Our technique and data contribute to elucidate ihSC-bacteria interactions.
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Affiliation(s)
- Lilian Jorge Hill
- Laboratory of Molecular Microbial Ecology, Institute of Microbiology Paulo de Góes, Federal University of Rio de Janeiro, Rio de Janeiro 21941-901, Brazil
| | | | - Caren Leite Spindola Vilela
- Laboratory of Molecular Microbial Ecology, Institute of Microbiology Paulo de Góes, Federal University of Rio de Janeiro, Rio de Janeiro 21941-901, Brazil
| | - Alessandro N Garritano
- Centre for Marine Science and Innovation, School of Biological, Earth and Environmental Sciences, The University of New South Wales, Sydney, NSW, Australia
| | - Helena Dias Muller Villela
- Red Sea Research Center, Biological and Environmental Science and Engineering Division, King Abdullah University of Science and Technology, Thuwal 23955, Kingdom of Saudi Arabia
| | - Flavia Lima do Carmo
- Laboratory of Molecular Microbial Ecology, Institute of Microbiology Paulo de Góes, Federal University of Rio de Janeiro, Rio de Janeiro 21941-901, Brazil
| | - Torsten Thomas
- Centre for Marine Science and Innovation, School of Biological, Earth and Environmental Sciences, The University of New South Wales, Sydney, NSW, Australia
| | - Raquel S. Peixoto
- Red Sea Research Center, Biological and Environmental Science and Engineering Division, King Abdullah University of Science and Technology, Thuwal 23955, Kingdom of Saudi Arabia
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6
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Gao Y, Wu J, Zhang D, Wang P, Wang Y, Zhu L, Li C, Wang W, Zhao J, Yang C, Yang K. The impact of alloying element Cu on corrosion and biofilms of 316L stainless steel exposed to seawater. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2024; 31:18842-18855. [PMID: 38351355 DOI: 10.1007/s11356-024-32354-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Accepted: 02/02/2024] [Indexed: 03/09/2024]
Abstract
Copper-containing stainless steel (SS) has been reported to mitigate biofilms in industrial and clinical environments. However, the impact of copper released from copper-containing SS in natural seawater on biofilms and corrosion is still unclear. In this study, three kinds of 316L SS were immersed in natural seawater for 6 months, and the pitting depth decreased in the order: 316L-Cu SS (annealed) > 316L SS > 316L-Cu SS (aged). The biofilm thickness and number of sessile cells on the surface of 316L-Cu SS (annealed) and 316L SS were similar but notably greater than those of 316L-Cu SS (aged). Furthermore, the results of the community analysis indicated that the addition of copper in 316L-Cu SS (aged) reduced the diversity and richness of the microbial community, resulting in a significant reduction in the number of genera constituting the biofilms. Copper ions exhibit a broad-spectrum bactericidal effect, effectively reducing the abundance of dominant populations and microbial genera in the biofilms, thereby mitigating pitting corrosion induced by microorganisms. In addition, the PCoA scatter plot showed that time also played an important role in the regulation of microbial community structure.
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Affiliation(s)
- Yaohua Gao
- Key Laboratory of Marine Environmental Corrosion and Biofouling, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China
- Open Studio for Marine Corrosion and Protection, Laoshan Laboratory, Qingdao, 266237, China
- Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, 266071, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Jiajia Wu
- Key Laboratory of Marine Environmental Corrosion and Biofouling, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China.
- Open Studio for Marine Corrosion and Protection, Laoshan Laboratory, Qingdao, 266237, China.
- Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, 266071, China.
| | - Dun Zhang
- Key Laboratory of Marine Environmental Corrosion and Biofouling, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China
- Open Studio for Marine Corrosion and Protection, Laoshan Laboratory, Qingdao, 266237, China
- Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, 266071, China
| | - Peng Wang
- Key Laboratory of Marine Environmental Corrosion and Biofouling, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China
- Open Studio for Marine Corrosion and Protection, Laoshan Laboratory, Qingdao, 266237, China
- Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, 266071, China
| | - Yi Wang
- Key Laboratory of Marine Environmental Corrosion and Biofouling, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China
- Open Studio for Marine Corrosion and Protection, Laoshan Laboratory, Qingdao, 266237, China
- Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, 266071, China
| | - Liyang Zhu
- Key Laboratory of Marine Environmental Corrosion and Biofouling, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China
- Open Studio for Marine Corrosion and Protection, Laoshan Laboratory, Qingdao, 266237, China
- Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, 266071, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Ce Li
- Key Laboratory of Marine Environmental Corrosion and Biofouling, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China
- Open Studio for Marine Corrosion and Protection, Laoshan Laboratory, Qingdao, 266237, China
- Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, 266071, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Wenkai Wang
- Key Laboratory of Marine Environmental Corrosion and Biofouling, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China
- Open Studio for Marine Corrosion and Protection, Laoshan Laboratory, Qingdao, 266237, China
- Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, 266071, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Jinlong Zhao
- Institute of Metal Research, Chinese Academy of Sciences, Shenyang, 110016, China
| | - Chunguang Yang
- Institute of Metal Research, Chinese Academy of Sciences, Shenyang, 110016, China
| | - Ke Yang
- Institute of Metal Research, Chinese Academy of Sciences, Shenyang, 110016, China
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7
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Walton JL, Buchan A. Evidence for novel polycyclic aromatic hydrocarbon degradation pathways in culturable marine isolates. Microbiol Spectr 2024; 12:e0340923. [PMID: 38084970 PMCID: PMC10783047 DOI: 10.1128/spectrum.03409-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Accepted: 11/10/2023] [Indexed: 01/13/2024] Open
Abstract
IMPORTANCE Polycyclic aromatic hydrocarbon (PAH) pollution is widespread throughout marine environments and significantly affects native flora and fauna. Investigating microbes responsible for degrading PAHs in these environments provides a greater understanding of natural attenuation in these systems. In addition, the use of culture-based approaches to inform bioinformatic and omics-based approaches is useful in identifying novel mechanisms of PAH degradation that elude genetic biomarker-based investigations. Furthermore, culture-based approaches allow for the study of PAH co-metabolism, which increasingly appears to be a prominent mechanism for PAH degradation in marine microbes.
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Affiliation(s)
- Jillian L. Walton
- Department of Microbiology, University of Tennessee, Knoxville, Tennessee, USA
| | - Alison Buchan
- Department of Microbiology, University of Tennessee, Knoxville, Tennessee, USA
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8
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Panteli N, Feidantsis K, Demertzioglou M, Paralika V, Karapanagiotis S, Mylonas CC, Kormas KA, Mente E, Makridis P, Antonopoulou E. The Probiotic Phaeobacter inhibens Provokes Hypertrophic Growth via Activation of the IGF-1/Akt Pathway during the Process of Metamorphosis of Greater Amberjack ( Seriola dumerili, Risso 1810). Animals (Basel) 2023; 13:2154. [PMID: 37443952 DOI: 10.3390/ani13132154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 06/04/2023] [Accepted: 06/27/2023] [Indexed: 07/15/2023] Open
Abstract
Metamorphosis entails hormonally regulated morphological and physiological changes requiring high energy levels. Probiotics as feed supplements generate ameliorative effects on host nutrient digestion and absorption. Thereby, the aim of the present research was to investigate the impact of the probiotic Phaeobacter inhibens as a water additive on cellular signaling pathways in the metamorphosis of greater amberjack (Seriola dumerili). Activation of insulin-like growth factor type 1 receptor (IGF-1R), protein kinase B (Akt), mitogen-activated protein kinases (MAPKs) and AMP-activated protein kinase (AMPK), induction of heat shock proteins (Hsps), and programmed cell death were assessed through SDS-Page/immunoblot analysis, while energy metabolism was determined through enzymatic activities. According to the results, greater amberjack reared in P. inhibens-enriched water entered the metamorphic phase with greater body length, while protein synthesis was triggered to facilitate the hypertrophic growth as indicated by IGF-1/Akt activation and AMPK inhibition. Contrarily, MAPKs levels were reduced, whereas variations in Hsps response were evident in the probiotic treatment. Apoptosis and autophagy were mobilized potentially for the structural remodeling processes. Furthermore, the elevated enzymatic activities of intermediary metabolism highlighted the excess energy demands of metamorphosis. Collectively, the present findings demonstrate that P. inhibens may reinforce nutrient utilization, thus leading greater amberjack to an advanced growth and developmental state.
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Affiliation(s)
- Nikolas Panteli
- Department of Zoology, School of Biology, Faculty of Sciences, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
| | - Konstantinos Feidantsis
- Department of Zoology, School of Biology, Faculty of Sciences, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
- Department of Fisheries & Aquaculture, University of Patras, 26504 Mesolonghi, Greece
| | - Maria Demertzioglou
- Department of Zoology, School of Biology, Faculty of Sciences, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
| | - Vasiliki Paralika
- Department of Biology, University of Patras, 26504 Rio Achaias, Greece
| | | | - Constantinos C Mylonas
- Institute of Marine Biology, Biotechnology and Aquaculture, Hellenic Center for Marine Research, P.O. Box 2214, 71003 Heraklion, Greece
| | - Konstantinos Ar Kormas
- Department of Ichthyology and Aquatic Environment, School of Agricultural Sciences, University of Thessaly, 38446 Volos, Greece
- Agricultural Development Institute, University Research and Innovation Centre "IASON", Argonafton & Filellinon, 38221 Volos, Greece
| | - Eleni Mente
- Laboratory of Ichthyology-Culture and Pathology of Aquatic Animals, School of Veterinary Medicine, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
| | - Pavlos Makridis
- Department of Biology, University of Patras, 26504 Rio Achaias, Greece
| | - Efthimia Antonopoulou
- Department of Zoology, School of Biology, Faculty of Sciences, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
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9
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Barak-Gavish N, Dassa B, Kuhlisch C, Nussbaum I, Brandis A, Rosenberg G, Avraham R, Vardi A. Bacterial lifestyle switch in response to algal metabolites. eLife 2023; 12:e84400. [PMID: 36691727 PMCID: PMC9873259 DOI: 10.7554/elife.84400] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Accepted: 01/05/2023] [Indexed: 01/19/2023] Open
Abstract
Unicellular algae, termed phytoplankton, greatly impact the marine environment by serving as the basis of marine food webs and by playing central roles in the biogeochemical cycling of elements. The interactions between phytoplankton and heterotrophic bacteria affect the fitness of both partners. It is becoming increasingly recognized that metabolic exchange determines the nature of such interactions, but the underlying molecular mechanisms remain underexplored. Here, we investigated the molecular and metabolic basis for the bacterial lifestyle switch, from coexistence to pathogenicity, in Sulfitobacter D7 during its interaction with Emiliania huxleyi, a cosmopolitan bloom-forming phytoplankter. To unravel the bacterial lifestyle switch, we analyzed bacterial transcriptomes in response to exudates derived from algae in exponential growth and stationary phase, which supported the Sulfitobacter D7 coexistence and pathogenicity lifestyles, respectively. In pathogenic mode, Sulfitobacter D7 upregulated flagellar motility and diverse transport systems, presumably to maximize assimilation of E. huxleyi-derived metabolites released by algal cells upon cell death. Algal dimethylsulfoniopropionate (DMSP) was a pivotal signaling molecule that mediated the transition between the lifestyles, supporting our previous findings. However, the coexisting and pathogenic lifestyles were evident only in the presence of additional algal metabolites. Specifically, we discovered that algae-produced benzoate promoted the growth of Sulfitobacter D7 and hindered the DMSP-induced lifestyle switch to pathogenicity, demonstrating that benzoate is important for maintaining the coexistence of algae and bacteria. We propose that bacteria can sense the physiological state of the algal host through changes in the metabolic composition, which will determine the bacterial lifestyle during interaction.
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Affiliation(s)
- Noa Barak-Gavish
- Department of Plant and Environmental Sciences, Weizmann Institute of ScienceRehovotIsrael
| | - Bareket Dassa
- Life Sciences Core Facilities, Weizmann Institute of ScienceRehovotIsrael
| | - Constanze Kuhlisch
- Department of Plant and Environmental Sciences, Weizmann Institute of ScienceRehovotIsrael
| | - Inbal Nussbaum
- Department of Plant and Environmental Sciences, Weizmann Institute of ScienceRehovotIsrael
| | - Alexander Brandis
- Life Sciences Core Facilities, Weizmann Institute of ScienceRehovotIsrael
| | - Gili Rosenberg
- Department of Biological Regulation, Weizmann Institute of ScienceRehovotIsrael
| | - Roi Avraham
- Department of Biological Regulation, Weizmann Institute of ScienceRehovotIsrael
| | - Assaf Vardi
- Department of Plant and Environmental Sciences, Weizmann Institute of ScienceRehovotIsrael
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10
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Armes AC, Walton JL, Buchan A. Quorum Sensing and Antimicrobial Production Orchestrate Biofilm Dynamics in Multispecies Bacterial Communities. Microbiol Spectr 2022; 10:e0261522. [PMID: 36255295 PMCID: PMC9769649 DOI: 10.1128/spectrum.02615-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Accepted: 09/16/2022] [Indexed: 01/07/2023] Open
Abstract
Microbial interactions are often mediated by diffusible small molecules, including secondary metabolites, that play roles in cell-to-cell signaling and inhibition of competitors. Biofilms are often "hot spots" for high concentrations of bacteria and their secondary metabolites, which make them ideal systems for the study of small-molecule contributions to microbial interactions. Here, we use a five-member synthetic community consisting of Roseobacteraceae representatives to investigate the role of secondary metabolites on microbial biofilm dynamics. One synthetic community member, Rhodobacterales strain Y4I, possesses two acylated homoserine lactone (AHL)-based cell-to-cell signaling systems (pgaRI and phaRI) as well as a nonribosomal peptide synthase gene (igi) cluster that encodes the antimicrobial indigoidine. Through serial substitution of Y4I with mutants deficient in single signaling molecule pathways, the contribution of these small-molecule systems could be assessed. As secondary metabolite production is dependent upon central metabolites, the influence of growth substrate (i.e., complex medium versus defined medium with a single carbon substrate) on these dynamics was also considered. Depending on the Y4I mutant genotype included, community dynamics ranged from competitive to cooperative. The observed interactions were mostly competitive in nature. However, the community harboring a Y4I variant that was both impaired in quorum sensing (QS) pathways and unable to produce indigoidine (pgaR variant) shifted toward more cooperative interactions over time. These cooperative interactions were enhanced in the defined growth medium. The results presented provide a framework for deciphering complex, small-molecule-mediated interactions that have broad application to microbial biology. IMPORTANCE Microbial biofilms play critical roles in marine ecosystems and are hot spots for microbial interactions that play a role in the development and function of these communities. Roseobacteraceae are an abundant and active family of marine heterotrophic bacteria forming close associations with phytoplankton and carrying out key transformations in biogeochemical cycles. Group members are aggressive primary colonizers of surfaces, where they set the stage for the development of multispecies biofilm communities. Few studies have examined the impact of secondary metabolites, such as cell-to-cell signaling and antimicrobial production, on marine microbial biofilm community structure. Here, we assessed the impact of secondary metabolites on microbial interactions using a synthetic, five-member Roseobacteraceae community by measuring species composition and biomass production during biofilm growth. We present evidence that secondary metabolites influence social behaviors within these multispecies microbial biofilms, thereby improving understanding of bacterial secondary metabolite production influence on social behaviors within marine microbial biofilm communities.
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Affiliation(s)
- April C. Armes
- Department of Microbiology, University of Tennessee, Knoxville, Tennessee, USA
| | - Jillian L. Walton
- Department of Microbiology, University of Tennessee, Knoxville, Tennessee, USA
| | - Alison Buchan
- Department of Microbiology, University of Tennessee, Knoxville, Tennessee, USA
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11
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What Glues the Glue to the Cell Surface? J Bacteriol 2022; 204:e0038622. [PMID: 36286485 PMCID: PMC9664948 DOI: 10.1128/jb.00386-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In the
Caulobacterales
, a highly adhesive polysaccharide called the holdfast mediates attachment to exogenous surfaces. The mechanism by which this polysaccharide is anchored to the cell envelope is not well defined.
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12
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Mansky J, Wang H, Ebert M, Härtig E, Jahn D, Tomasch J, Wagner-Döbler I. The Influence of Genes on the "Killer Plasmid" of Dinoroseobacter shibae on Its Symbiosis With the Dinoflagellate Prorocentrum minimum. Front Microbiol 2022; 12:804767. [PMID: 35154034 PMCID: PMC8831719 DOI: 10.3389/fmicb.2021.804767] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 12/13/2021] [Indexed: 01/05/2023] Open
Abstract
The marine bacterium Dinoroseobacter shibae shows a Jekyll-and-Hyde behavior in co-culture with the dinoflagellate Prorocentrum minimum: In the initial symbiotic phase it provides the essential vitamins B12 (cobalamin) and B1 (thiamine) to the algae. In the later pathogenic phase it kills the dinoflagellate. The killing phenotype is determined by the 191 kb plasmid and can be conjugated into other Roseobacters. From a transposon-library of D. shibae we retrieved 28 mutants whose insertion sites were located on the 191 kb plasmid. We co-cultivated each of them with P. minimum in L1 medium lacking vitamin B12. With 20 mutant strains no algal growth beyond the axenic control lacking B12 occurred. Several of these genes were predicted to encode proteins from the type IV secretion system (T4SS). They are apparently essential for establishing the symbiosis. With five transposon mutant strains, the initial symbiotic phase was intact but the later pathogenic phase was lost in co-culture. In three of them the insertion sites were located in an operon predicted to encode genes for biotin (B7) uptake. Both P. minimum and D. shibae are auxotrophic for biotin. We hypothesize that the bacterium depletes the medium from biotin resulting in apoptosis of the dinoflagellate.
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Affiliation(s)
- Johannes Mansky
- Institute for Microbiology, Technical University of Braunschweig, Braunschweig, Germany
| | - Hui Wang
- Institute for Microbiology, Technical University of Braunschweig, Braunschweig, Germany
| | - Matthias Ebert
- Institute for Microbiology, Technical University of Braunschweig, Braunschweig, Germany
| | - Elisabeth Härtig
- Institute for Microbiology, Technical University of Braunschweig, Braunschweig, Germany
| | - Dieter Jahn
- Institute for Microbiology, Technical University of Braunschweig, Braunschweig, Germany
| | - Jürgen Tomasch
- Laboratory of Anoxygenic Phototrophs, Institute of Microbiology, Czech Academy of Sciences – Centre Algatech, Třeboň, Czechia
| | - Irene Wagner-Döbler
- Institute for Microbiology, Technical University of Braunschweig, Braunschweig, Germany
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13
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Chao C, Wang L, Li Y, Yan Z, Liu H, Yu D, Liu C. Response of sediment and water microbial communities to submerged vegetations restoration in a shallow eutrophic lake. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 801:149701. [PMID: 34419912 DOI: 10.1016/j.scitotenv.2021.149701] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 08/10/2021] [Accepted: 08/12/2021] [Indexed: 06/13/2023]
Abstract
Submerged macrophytes are the main primary producers in shallow lakes and play an important role in structuring communities. Aquatic microbes are also an important component of aquatic ecosystems and play important roles in maintaining the health and stability of ecosystems. However, little is known about the interactions between macrophytes and microbes during the reintroduction of submerged vegetation. Here, we chose restored zones dominated by four different submerged vegetations and a bare zone in a shallow eutrophic lake to unveil the microbial diversity, composition and structure changes in sediment and water samples after submerged macrophytes were recovered for one and a half years (July 2019) and two years (April 2020). We found that the recovery of submerged vegetations decreased phosphorus content in water and sediments but increased nitrogen and carbon content in sediments. We observed that the transparency of water in the restored zones was significantly higher than that in the bare zone in July. The recovery of submerged vegetations significantly influenced the alpha diversity of bacterial communities in sediments, with higher values observed in restored zones than in bare zones, whereas no significant influence was found in the water samples. In July, the macrophyte species showed strong effects on the bacterial community composition in water and relatively little effect in sediment. However, a strong effect of the macrophyte species on the composition of bacterial communities in sediments was observed in April, which may be related to the decomposition of plant litter and the decay of detritus. Additionally, the dissimilarity of the sedimentary bacterial community may increase more slowly with environmental changes than the planktonic bacterial community dissimilarity. These results suggest that the large-scale restoration of aquatic macrophytes can not only improve water quality and change sediment characteristics but can also affect the diversity and compositions of bacterial communities, and these effects seem to be very long-lasting.
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Affiliation(s)
- Chuanxin Chao
- The National Field Station of Freshwater Ecosystem of Liangzi Lake, College of Life Science, Wuhan University, Wuhan, PR China
| | - Ligong Wang
- The National Field Station of Freshwater Ecosystem of Liangzi Lake, College of Life Science, Wuhan University, Wuhan, PR China
| | - Yang Li
- The National Field Station of Freshwater Ecosystem of Liangzi Lake, College of Life Science, Wuhan University, Wuhan, PR China
| | - Zhiwei Yan
- The National Field Station of Freshwater Ecosystem of Liangzi Lake, College of Life Science, Wuhan University, Wuhan, PR China
| | - Huimin Liu
- The National Field Station of Freshwater Ecosystem of Liangzi Lake, College of Life Science, Wuhan University, Wuhan, PR China
| | - Dan Yu
- The National Field Station of Freshwater Ecosystem of Liangzi Lake, College of Life Science, Wuhan University, Wuhan, PR China
| | - Chunhua Liu
- The National Field Station of Freshwater Ecosystem of Liangzi Lake, College of Life Science, Wuhan University, Wuhan, PR China.
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14
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Isaac A, Francis B, Amann RI, Amin SA. Tight Adherence (Tad) Pilus Genes Indicate Putative Niche Differentiation in Phytoplankton Bloom Associated Rhodobacterales. Front Microbiol 2021; 12:718297. [PMID: 34447362 PMCID: PMC8383342 DOI: 10.3389/fmicb.2021.718297] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 07/19/2021] [Indexed: 11/14/2022] Open
Abstract
The multiple interactions of phytoplankton and bacterioplankton are central for our understanding of aquatic environments. A prominent example of those is the consistent association of diatoms with Alphaproteobacteria of the order Rhodobacterales. These photoheterotrophic bacteria have traditionally been described as generalists that scavenge dissolved organic matter. Many observations suggest that members of this clade are specialized in colonizing the microenvironment of diatom cells, known as the phycosphere. However, the molecular mechanisms that differentiate Rhodobacterales generalists and phycosphere colonizers are poorly understood. We investigated Rhodobacterales in the North Sea during the 2010–2012 spring blooms using a time series of 38 deeply sequenced metagenomes and 10 metaproteomes collected throughout these events. Rhodobacterales metagenome assembled genomes (MAGs) were recurrently abundant. They exhibited the highest gene enrichment and protein expression of small-molecule transporters, such as monosaccharides, thiamine and polyamine transporters, and anaplerotic pathways, such as ethylmalonyl and propanoyl-CoA metabolic pathways, all suggestive of a generalist lifestyle. Metaproteomes indicated that the species represented by these MAGs were the dominant suppliers of vitamin B12 during the blooms, concomitant with a significant enrichment of genes related to vitamin B12 biosynthesis suggestive of association with diatom phycospheres. A closer examination of putative generalists and colonizers showed that putative generalists had persistently higher relative abundance throughout the blooms and thus produced more than 80% of Rhodobacterales transport proteins, suggesting rapid growth. In contrast, putative phycosphere colonizers exhibited large fluctuation in relative abundance across the different blooms and correlated strongly with particular diatom species that were dominant during the blooms each year. The defining feature of putative phycosphere colonizers is the presence of the tight adherence (tad) gene cluster, which is responsible for the assembly of adhesive pili that presumably enable attachment to diatom hosts. In addition, putative phycosphere colonizers possessed higher prevalence of secondary metabolite biosynthetic gene clusters, particularly homoserine lactones, which can regulate bacterial attachment through quorum sensing. Altogether, these findings suggest that while many members of Rhodobacterales are competitive during diatom blooms, only a subset form close associations with diatoms by colonizing their phycospheres.
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Affiliation(s)
- Ashley Isaac
- Marine Microbial Ecology Laboratory, Biology Program, New York University Abu Dhabi, Abu Dhabi, United Arab Emirates.,Max Planck Institute for Marine Microbiology, Bremen, Germany
| | - Ben Francis
- Max Planck Institute for Marine Microbiology, Bremen, Germany
| | - Rudolf I Amann
- Max Planck Institute for Marine Microbiology, Bremen, Germany
| | - Shady A Amin
- Marine Microbial Ecology Laboratory, Biology Program, New York University Abu Dhabi, Abu Dhabi, United Arab Emirates
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15
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Wolter LA, Wietz M, Ziesche L, Breider S, Leinberger J, Poehlein A, Daniel R, Schulz S, Brinkhoff T. Pseudooceanicola algae sp. nov., isolated from the marine macroalga Fucus spiralis, shows genomic and physiological adaptations for an algae-associated lifestyle. Syst Appl Microbiol 2021; 44:126166. [PMID: 33310406 DOI: 10.1016/j.syapm.2020.126166] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 11/09/2020] [Accepted: 11/12/2020] [Indexed: 12/23/2022]
Abstract
The genus Pseudooceanicola from the alphaproteobacterial Roseobacter group currently includes ten validated species. We herein describe strain Lw-13eT, the first Pseudooceanicola species from marine macroalgae, isolated from the brown alga Fucus spiralis abundant at European and North American coasts. Physiological and pangenome analyses of Lw-13eT showed corresponding adaptive features. Adaptations to the tidal environment include a broad salinity tolerance, degradation of macroalgae-derived substrates (mannitol, mannose, proline), and resistance to several antibiotics and heavy metals. Notably, Lw-13eT can degrade oligomeric alginate via PL15 alginate lyase encoded in a polysaccharide utilization locus (PUL), rarely described for roseobacters to date. Plasmid localization of the PUL strengthens the importance of mobile genetic elements for evolutionary adaptations within the Roseobacter group. PL15 homologs were primarily detected in marine plant-associated metagenomes from coastal environments but not in the open ocean, corroborating its adaptive role in algae-rich habitats. Exceptional is the tolerance of Lw-13eT against the broad-spectrum antibiotic tropodithietic acid, produced by Phaeobacter spp. co-occurring in coastal habitats. Furthermore, Lw-13eT exhibits features resembling terrestrial plant-bacteria associations, i.e. biosynthesis of siderophores, terpenes and volatiles, which may contribute to mutual bacteria-algae interactions. Closest described relative of Lw-13eT is Pseudopuniceibacterium sediminis CY03T with 98.4% 16S rRNA gene sequence similarity. However, protein sequence-based core genome phylogeny and average nucleotide identity indicate affiliation of Lw-13eT with the genus Pseudooceanicola. Based on phylogenetic, physiological and (chemo)taxonomic distinctions, we propose strain Lw-13eT (=DSM 29013T=LMG 30557T) as a novel species with the name Pseudooceanicola algae.
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Affiliation(s)
- Laura A Wolter
- Institute for Chemistry and Biology of the Marine Environment, Oldenburg, Germany; JST ERATO Nomura Project, Faculty of Life and Environmental Sciences, Tsukuba, Japan.
| | - Matthias Wietz
- Institute for Chemistry and Biology of the Marine Environment, Oldenburg, Germany; Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany
| | - Lisa Ziesche
- Institute of Organic Chemistry, Technische Universität Braunschweig, Germany
| | - Sven Breider
- Institute for Chemistry and Biology of the Marine Environment, Oldenburg, Germany
| | - Janina Leinberger
- Institute for Chemistry and Biology of the Marine Environment, Oldenburg, Germany
| | - Anja Poehlein
- Institute of Microbiology and Genetics, Genomic and Applied Microbiology, and Göttingen Genomics Laboratory, Germany
| | - Rolf Daniel
- Institute of Microbiology and Genetics, Genomic and Applied Microbiology, and Göttingen Genomics Laboratory, Germany
| | - Stefan Schulz
- Institute of Organic Chemistry, Technische Universität Braunschweig, Germany
| | - Thorsten Brinkhoff
- Institute for Chemistry and Biology of the Marine Environment, Oldenburg, Germany.
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16
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Zaynab M, Chen H, Chen Y, Ouyang L, Yang X, Hu Z, Li S. Signs of biofilm formation in the genome of Labrenzia sp . PO1. Saudi J Biol Sci 2020; 28:1900-1912. [PMID: 33732076 PMCID: PMC7938128 DOI: 10.1016/j.sjbs.2020.12.041] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 12/20/2020] [Accepted: 12/23/2020] [Indexed: 02/06/2023] Open
Abstract
Labrenzia sp. are important components of marine ecology which play a key role in biochemical cycling. In this study, we isolated the Labrenzia sp. PO1 strain capable of forming biofilm, from the A. sanguinea culture. Growth analysis revealed that strain reached a logarithmic growth period at 24 hours. The whole genome of 6.21813 Mb of Labrezia sp. PO1 was sequenced and assembled into 15 scaffolds and 16 contigs, each with minimum and maximum lengths of 644 and 1,744,114 Mb. A total of 3,566 genes were classified into five pathways and 31 pathway groups. Of them, 521 genes encoded biofilm formation proteins, quorum sensing (QS) proteins, and ABC transporters. Gene Ontology annotation identified 49,272 genes that were involved in biological processes (33,425 genes), cellular components (7,031genes), and molecular function (7,816 genes). We recognised genes involved in bacterial quorum sensing, attachment, motility, and chemotaxis to investigate bacteria's ability to interact with the diatom phycosphere. As revealed by KEGG pathway analysis, several genes encoding ABC transporters exhibited a significant role during the growth and development of Labrenzia sp. PO1, indicating that ABC transporters may be involved in signalling pathways that enhance growth and biofilm formation.
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Affiliation(s)
- Madiha Zaynab
- College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China.,Shenzhen Key Laboratory of Marine Bioresource & Eco-environmental Sciences, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, Guangdong 518071, China
| | - Huirong Chen
- Shenzhen Key Laboratory of Marine Bioresource & Eco-environmental Sciences, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, Guangdong 518071, China
| | - Yufei Chen
- Shenzhen Key Laboratory of Marine Bioresource & Eco-environmental Sciences, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, Guangdong 518071, China
| | - Liao Ouyang
- College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China.,Shenzhen Key Laboratory of Marine Bioresource & Eco-environmental Sciences, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, Guangdong 518071, China
| | - Xuewei Yang
- Shenzhen Key Laboratory of Marine Bioresource & Eco-environmental Sciences, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, Guangdong 518071, China
| | - Zhangli Hu
- Shenzhen Key Laboratory of Marine Bioresource & Eco-environmental Sciences, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, Guangdong 518071, China
| | - Shuangfei Li
- Shenzhen Key Laboratory of Marine Bioresource & Eco-environmental Sciences, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, Guangdong 518071, China
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17
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18
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Chu X, Li S, Wang S, Luo D, Luo H. Gene loss through pseudogenization contributes to the ecological diversification of a generalist Roseobacter lineage. ISME JOURNAL 2020; 15:489-502. [PMID: 32999421 DOI: 10.1038/s41396-020-00790-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 09/13/2020] [Accepted: 09/21/2020] [Indexed: 12/11/2022]
Abstract
Ecologically relevant genes generally show patchy distributions among related bacterial genomes. This is commonly attributed to lateral gene transfer, whereas the opposite mechanism-gene loss-has rarely been explored. Pseudogenization is a major mechanism underlying gene loss, and pseudogenes are best characterized by comparing closely related genomes because of their short life spans. To explore the role of pseudogenization in microbial ecological diversification, we apply rigorous methods to characterize pseudogenes in the 279 newly sequenced Ruegeria isolates of the globally abundant Roseobacter group collected from two typical coastal habitats in Hong Kong, the coral Platygyra acuta and the macroalga Sargassum hemiphyllum. Pseudogenes contribute to ~16% of the accessory genomes of these strains. Ancestral state reconstruction reveals that many pseudogenization events are correlated with ancestral niche shifts. Specifically, genes related to resource scavenging and energy acquisition were often pseudogenized when roseobacters inhabiting carbon-limited and energy-poor coral skeleton switched to other resource-richer niches. For roseobacters inhabiting the macroalgal niches, genes for nitrogen regulation and carbohydrate utilization were important but became dispensable upon shift to coral skeleton where nitrate is abundant but carbohydrates are less available. Whereas low-energy-demanding secondary transporters are more favorable in coral skeleton, ATP-driven primary transporters are preferentially kept in the energy-replete macroalgal niches. Moreover, a large proportion of these families mediate organismal interactions, suggesting their rapid losses by pseudogenization as a potential response to host and niche shift. These findings illustrate an important role of pseudogenization in shaping genome content and driving ecological diversification of marine roseobacters.
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Affiliation(s)
- Xiao Chu
- Simon F. S. Li Marine Science Laboratory, School of Life Sciences and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, Hong Kong SAR
| | - Siyao Li
- Simon F. S. Li Marine Science Laboratory, School of Life Sciences and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, Hong Kong SAR
| | - Sishuo Wang
- Simon F. S. Li Marine Science Laboratory, School of Life Sciences and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, Hong Kong SAR
| | - Danli Luo
- Simon F. S. Li Marine Science Laboratory, School of Life Sciences and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, Hong Kong SAR
| | - Haiwei Luo
- Simon F. S. Li Marine Science Laboratory, School of Life Sciences and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, Hong Kong SAR. .,Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, 518000, China.
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19
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Fei C, Ochsenkühn MA, Shibl AA, Isaac A, Wang C, Amin SA. Quorum sensing regulates 'swim-or-stick' lifestyle in the phycosphere. Environ Microbiol 2020; 22:4761-4778. [PMID: 32896070 PMCID: PMC7693213 DOI: 10.1111/1462-2920.15228] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 09/03/2020] [Accepted: 09/04/2020] [Indexed: 12/12/2022]
Abstract
Interactions between phytoplankton and bacteria play major roles in global biogeochemical cycles and oceanic nutrient fluxes. These interactions occur in the microenvironment surrounding phytoplankton cells, known as the phycosphere. Bacteria in the phycosphere use either chemotaxis or attachment to benefit from algal excretions. Both processes are regulated by quorum sensing (QS), a cell–cell signalling mechanism that uses small infochemicals to coordinate bacterial gene expression. However, the role of QS in regulating bacterial attachment in the phycosphere is not clear. Here, we isolated a Sulfitobacter pseudonitzschiae F5 and a Phaeobacter sp. F10 belonging to the marine Roseobacter group and an Alteromonas macleodii F12 belonging to Alteromonadaceae, from the microbial community of the ubiquitous diatom Asterionellopsis glacialis. We show that only the Roseobacter group isolates (diatom symbionts) can attach to diatom transparent exopolymeric particles. Despite all three bacteria possessing genes involved in motility, chemotaxis, and attachment, only S. pseudonitzschiae F5 and Phaeobacter sp. F10 possessed complete QS systems and could synthesize QS signals. Using UHPLC–MS/MS, we identified three QS molecules produced by both bacteria of which only 3‐oxo‐C16:1‐HSL strongly inhibited bacterial motility and stimulated attachment in the phycosphere. These findings suggest that QS signals enable colonization of the phycosphere by algal symbionts.
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Affiliation(s)
- Cong Fei
- Marine Microbial Ecology Lab, Biology Program, New York University Abu Dhabi, Abu Dhabi, United Arab Emirates.,College of Resources and Environmental Science, Nanjing Agriculture University, Nanjing, China
| | - Michael A Ochsenkühn
- Marine Microbial Ecology Lab, Biology Program, New York University Abu Dhabi, Abu Dhabi, United Arab Emirates
| | - Ahmed A Shibl
- Marine Microbial Ecology Lab, Biology Program, New York University Abu Dhabi, Abu Dhabi, United Arab Emirates
| | - Ashley Isaac
- Marine Microbial Ecology Lab, Biology Program, New York University Abu Dhabi, Abu Dhabi, United Arab Emirates.,International Max Planck Research School of Marine Microbiology, University of Bremen, Bremen, Germany
| | - Changhai Wang
- College of Resources and Environmental Science, Nanjing Agriculture University, Nanjing, China
| | - Shady A Amin
- Marine Microbial Ecology Lab, Biology Program, New York University Abu Dhabi, Abu Dhabi, United Arab Emirates
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20
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Antunes JT, Sousa AGG, Azevedo J, Rego A, Leão PN, Vasconcelos V. Distinct Temporal Succession of Bacterial Communities in Early Marine Biofilms in a Portuguese Atlantic Port. Front Microbiol 2020; 11:1938. [PMID: 32849482 PMCID: PMC7432428 DOI: 10.3389/fmicb.2020.01938] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Accepted: 07/22/2020] [Indexed: 12/13/2022] Open
Abstract
Marine biofilms are known to influence the corrosion of metal surfaces in the marine environment. Despite some recent research, the succession of bacterial communities colonizing artificial surfaces remains uncharacterized in some temporal settings. More specifically, it is not fully known if bacterial colonizers of artificial surfaces are similar or distinct in the different seasons of the year. In particular the study of early biofilms, in which the bacterial cells communities first adhere to artificial surfaces, are crucial for the development of the subsequent biofilm communities. In this work, we used amplicon-based NGS (next-generation sequencing) and universal 16S rRNA bacterial primers to characterize the early biofilm bacterial communities growing on 316 L stainless steel surfaces in a Northern Portugal port. Sampling spanned 30-day periods in two distinct seasons (spring and winter). Biofilm communities growing in steel surfaces covered with an anti-corrosion paint and planktonic communities from the same location were also characterized. Our results demonstrated that distinct temporal patterns were observed in the sampled seasons. Specifically, a significantly higher abundance of Gammaproteobacteria and Mollicutes was found on the first days of biofilm growth in spring (day 1 to day 4) and a higher abundance of Alphaproteobacteria during the same days of biofilm growth in winter. In the last sampled day (day 30), the spring biofilms significantly shifted toward a dominance of photoautotrophic groups (mostly diatoms) and were also colonized by some macrofouling communities, something not observed during the winter sampling. Our results revealed that bacterial composition in the biofilms was particularly affected by the sampled day of the specific season, more so than the overall effect of the season or overall sampling day of both seasons. Additionally, the application of a non-fouling-release anti-corrosion paint in the steel plates resulted in a significantly lower diversity compared with plates without paint, but this was only observed during spring. We suggest that temporal succession of marine biofilm communities should be taken in consideration for future antifouling/anti-biofilm applications.
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Affiliation(s)
- Jorge T. Antunes
- Centro Interdisciplinar de Investigação Marinha e Ambiental, Universidade do Porto, Matosinhos, Portugal
- Departamento de Biologia, Faculdade de Ciências, Universidade do Porto, Porto, Portugal
| | - António G. G. Sousa
- Centro Interdisciplinar de Investigação Marinha e Ambiental, Universidade do Porto, Matosinhos, Portugal
| | - Joana Azevedo
- Centro Interdisciplinar de Investigação Marinha e Ambiental, Universidade do Porto, Matosinhos, Portugal
| | - Adriana Rego
- Centro Interdisciplinar de Investigação Marinha e Ambiental, Universidade do Porto, Matosinhos, Portugal
- Institute of Biomedical Sciences Abel Salazar, University of Porto, Porto, Portugal
| | - Pedro N. Leão
- Centro Interdisciplinar de Investigação Marinha e Ambiental, Universidade do Porto, Matosinhos, Portugal
| | - Vitor Vasconcelos
- Centro Interdisciplinar de Investigação Marinha e Ambiental, Universidade do Porto, Matosinhos, Portugal
- Departamento de Biologia, Faculdade de Ciências, Universidade do Porto, Porto, Portugal
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21
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Ng JCY, Chiu JMY. Changes in biofilm bacterial communities in response to combined effects of hypoxia, ocean acidification and nutrients from aquaculture activity in Three Fathoms Cove. MARINE POLLUTION BULLETIN 2020; 156:111256. [PMID: 32510398 DOI: 10.1016/j.marpolbul.2020.111256] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Revised: 05/04/2020] [Accepted: 05/07/2020] [Indexed: 06/11/2023]
Abstract
Anthropogenic nutrient enrichment results in hypoxia, ocean acidification and elevated nutrients (HOAN) in coastal environments throughout the world. Here, we examined the composition of biofilm bacterial communities from a nutrient-excessive fish farm with low dissolved oxygen (DO) and pH levels using 16S rRNA gene sequencing. HOAN was accompanied by higher bacterial diversity and richness, and resulted in an altered community composition than the control site. HOAN resulted in more Flavobacteriales, Rhizobiales, Epsilonproteobacteria and Vibrionales, but less Oceanospirillales and Alteromonadales. Photobacterium sp. and Vibrio sp. were mostly found to be exclusive to HOAN conditions, suggesting that HOAN could possibly proliferate the presence of these potential pathogens. Our study suggests the complexity of bacterial communities to hypoxia and acidification in response to increased nutrient loads, along with identities of nutrient, oxygen and pH-susceptible bacterial groups that are most likely affected under this ocean trend.
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Affiliation(s)
- Jenny C Y Ng
- Department of Biology, Hong Kong Baptist University, Hong Kong, China
| | - Jill M Y Chiu
- Department of Biology, Hong Kong Baptist University, Hong Kong, China.
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22
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Basso JTR, Ankrah NYD, Tuttle MJ, Grossman AS, Sandaa RA, Buchan A. Genetically similar temperate phages form coalitions with their shared host that lead to niche-specific fitness effects. THE ISME JOURNAL 2020; 14:1688-1700. [PMID: 32242083 PMCID: PMC7305329 DOI: 10.1038/s41396-020-0637-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Revised: 03/08/2020] [Accepted: 03/16/2020] [Indexed: 01/07/2023]
Abstract
Temperate phages engage in long-term associations with their hosts that may lead to mutually beneficial interactions, of which the full extent is presently unknown. Here, we describe an environmentally relevant model system with a single host, a species of the Roseobacter clade of marine bacteria, and two genetically similar phages (ɸ-A and ɸ-D). Superinfection of a ɸ-D lysogenized strain (CB-D) with ɸ-A particles resulted in a lytic infection, prophage induction, and conversion of a subset of the host population, leading to isolation of a newly ɸ-A lysogenized strain (CB-A). Phenotypic differences, predicted to result from divergent lysogenic-lytic switch mechanisms, are evident between these lysogens, with CB-A displaying a higher incidence of spontaneous induction. Doubling times of CB-D and CB-A in liquid culture are 75 and 100 min, respectively. As cell cultures enter stationary phase, CB-A viable counts are half of CB-D. Consistent with prior evidence that cell lysis enhances biofilm formation, CB-A produces twice as much biofilm biomass as CB-D. As strains are susceptible to infection by the opposing phage type, co-culture competitions were performed to test fitness effects. When grown planktonically, CB-A outcompeted CB-D three to one. Yet, during biofilm growth, CB-D outcompeted CB-A three to one. These results suggest that genetically similar phages can have divergent influence on the competitiveness of their shared hosts in distinct environmental niches, possibly due to a complex form of phage-mediated allelopathy. These findings have implications for enhanced understanding of the eco-evolutionary dynamics of host-phage interactions that are pervasive in all ecosystems.
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Affiliation(s)
- Jonelle T R Basso
- Department of Microbiology, University of Tennessee Knoxville, 1311 Cumberland Avenue, 307 Ken and Blaire Mossman Bldg., Knoxville, TN, 37996, USA
| | - Nana Y D Ankrah
- Department of Microbiology, University of Tennessee Knoxville, 1311 Cumberland Avenue, 307 Ken and Blaire Mossman Bldg., Knoxville, TN, 37996, USA
- Department of Entomology, Cornell University, 5136 Comstock Hall, Ithaca, NY, 14853, USA
| | - Matthew J Tuttle
- Department of Microbiology, University of Tennessee Knoxville, 1311 Cumberland Avenue, 307 Ken and Blaire Mossman Bldg., Knoxville, TN, 37996, USA
| | - Alex S Grossman
- Department of Microbiology, University of Tennessee Knoxville, 1311 Cumberland Avenue, 307 Ken and Blaire Mossman Bldg., Knoxville, TN, 37996, USA
| | - Ruth-Anne Sandaa
- Department of Biological Sciences, University of Bergen, PO 7803, N-5020, Bergen, Norway
| | - Alison Buchan
- Department of Microbiology, University of Tennessee Knoxville, 1311 Cumberland Avenue, 307 Ken and Blaire Mossman Bldg., Knoxville, TN, 37996, USA.
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Capão A, Moreira-Filho P, Garcia M, Bitati S, Procópio L. Marine bacterial community analysis on 316L stainless steel coupons by Illumina MiSeq sequencing. Biotechnol Lett 2020; 42:1431-1448. [PMID: 32472186 DOI: 10.1007/s10529-020-02927-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Accepted: 05/26/2020] [Indexed: 11/30/2022]
Abstract
In order to evaluate the corrosive action of microorganisms on 316L metal exposed directly to a marine environment, a system was designed to immerse coupons in seawater. After periods of 30, 60 and 90 days, the coupons were recovered, the corrosion rates evaluated and the biofilm samples on their surface were analyzed by 16S rRNA gene sequencing. The results of the corrosion rate showed an acceleration over the entire experimental period. Alpha diversity measurements showed higher rates after 60 days of the experiment, while abundance measurements showed higher rates after 90 days of exposure to the marine environment. The beta-diversity results showed a clear separation between the three conditions and proximity in the indices between replicates of the same experimental condition. The results of 16S rRNA gene sequencing showed that after 30 days of exposure to seawater, there was massive representativeness of the pioneer bacteria, Gamma and Alphaproteobacteria, with emphasis on the genera Alcanivorax, Oceanospirillum and Shewanella. At the 60-day analysis, the Gammaproteobacteria class remained dominant, followed by Alphaproteobacteria and Flavobacteria, and the main representatives were Flexibacter and Pseudoalteromonas. In the last analysis, after 90 days, a change in the described bacterial community profile was observed. The Gammaproteobacteria class was still the largest in diversity and OTUs. The most predominant genera in number of OTUs were Alteromonas, Bacteriovorax and, Nautella. Our results describe a change in the microbial community over coupons directly exposed to the marine environment, suggesting a redirection to the formation of a mature biofilm. The conditions created by the biofilm structure suggest said condition favor biocorrosion on the analyzed coupons.
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Affiliation(s)
- Artur Capão
- Microbial Corrosion Laboratory, Estácio University (UNESA), Bispo Street, 83, Room, AG405, Rio de Janeiro, Rio de Janeiro, ZIP Code 20261-063, Brazil
| | - Paulo Moreira-Filho
- Microbial Corrosion Laboratory, Estácio University (UNESA), Bispo Street, 83, Room, AG405, Rio de Janeiro, Rio de Janeiro, ZIP Code 20261-063, Brazil
| | - Maurício Garcia
- Microbial Corrosion Laboratory, Estácio University (UNESA), Bispo Street, 83, Room, AG405, Rio de Janeiro, Rio de Janeiro, ZIP Code 20261-063, Brazil
| | - Suleima Bitati
- Microbial Corrosion Laboratory, Estácio University (UNESA), Bispo Street, 83, Room, AG405, Rio de Janeiro, Rio de Janeiro, ZIP Code 20261-063, Brazil
| | - Luciano Procópio
- Microbial Corrosion Laboratory, Estácio University (UNESA), Bispo Street, 83, Room, AG405, Rio de Janeiro, Rio de Janeiro, ZIP Code 20261-063, Brazil. .,Industrial Microbiology and Bioremediation Department, Federal University of Rio de Janeiro (UFRJ), Caxias, Rio de Janeiro, Brazil.
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24
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Thomas FA, Sinha RK, Krishnan KP. Bacterial community structure of a glacio-marine system in the Arctic (Ny-Ålesund, Svalbard). THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 718:135264. [PMID: 31848061 DOI: 10.1016/j.scitotenv.2019.135264] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Revised: 10/25/2019] [Accepted: 10/27/2019] [Indexed: 06/10/2023]
Abstract
The bacterial community composition of a valley glacier in Svalbard, its pro-glacial channels, and the associated downstream fjord ecosystem was investigated so as to figure out the degree to which downslope transport of microbes from the glacier systems along a hydrological continuum impose an effect on the patterns of diversity in the fjord system. A combination of culture based and high-throughput amplicon sequencing approach was followed which resulted in significant variation (R = 0.873, p = 0.001) in the bacterial community structure between these ecosystems. Dominance of sequences belonging to class β-Proteobacteria was seen in the glacier snow, ice and melt waters (MW) while a relatively higher abundance of OTUs belonging to α-Proteobacteria and Verrucomicrobiae demarcated the fjord waters. Similarity percentage (SIMPER) analysis of the Operational Taxonomic Units (OTUs) showed that OTU 1,105,280 (9.15%) and OTU 331 (6.5%) belonging to Burkholderiaceae (β-proteobacteria) and OTU 101,660 (5.76%) and OTU 520 (5.07%) belonging to Rhodobacteraceae (α-proteobacteria) contributed maximum to the overall dissimilarity between the sampling sites. The bacterial community from the MWs were found to be true signatures of the glacier ecosystem while the Kongsfjorden bacterial fraction mostly represented heterotrophic marine taxa influenced by warm Atlantic waters and presence of organic matter. Significant presence of unknown taxa in the MWs suggests the need to study such unexplored, transient niches for a better understanding of the associated microbial processes. Among the various environmental parameters measured, nutrients (NO3- and SiO42-) were found to exhibit strong association with the MW bacterial community while temperature, trace metals, Cl- and SO42- ions were found to influence the fjord bacterial community. The significant differences in the bacterial community composition between the glacier and the fjord ecosystem suggest the unique nature of these systems which in turn is influenced by the associated environmental parameters.
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Affiliation(s)
- Femi Anna Thomas
- National Centre for Polar and Ocean Research, Headland Sada, Vasco da Gama, Goa 403804, India; School of Earth, Ocean and Atmospheric Sciences, Goa University, Taleigao Plateau Goa 403206, India
| | - Rupesh Kumar Sinha
- National Centre for Polar and Ocean Research, Headland Sada, Vasco da Gama, Goa 403804, India
| | - K P Krishnan
- National Centre for Polar and Ocean Research, Headland Sada, Vasco da Gama, Goa 403804, India.
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25
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Biodiversity of Microorganisms Colonizing the Surface of Polystyrene Samples Exposed to Different Aqueous Environments. SUSTAINABILITY 2020. [DOI: 10.3390/su12093624] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The contamination of marine and freshwater ecosystems with the items from thermoplastics, including polystyrene (PS), necessitates the search for efficient microbial degraders of these polymers. In the present study, the composition of prokaryotes in biofilms formed on PS samples incubated in seawater and the industrial water of a petrochemical plant were investigated. Using a high-throughput sequencing of the V3–V4 region of the 16S rRNA gene, the predominance of Alphaproteobacteria (Blastomonas), Bacteroidetes (Chryseolinea), and Gammaproteobacteria (Arenimonas and Pseudomonas) in the biofilms on PS samples exposed to industrial water was revealed. Alphaproteobacteria (Erythrobacter) predominated on seawater-incubated PS samples. The local degradation of the PS samples was confirmed by scanning microscopy. The PS-colonizing microbial communities in industrial water differed significantly from the PS communities in seawater. Both communities have a high potential ability to carry out the carbohydrates and amino acids metabolism, but the potential for xenobiotic degradation, including styrene degradation, was relatively higher in the biofilms in industrial water. Bacteria of the genera Erythrobacter, Maribacter, and Mycobacterium were potential styrene-degraders in seawater, and Pseudomonas and Arenimonas in industrial water. Our results suggest that marine and industrial waters contain microbial populations potentially capable of degrading PS, and these populations may be used for the isolation of efficient PS degraders.
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26
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Barnier C, Clerissi C, Lami R, Intertaglia L, Lebaron P, Grimaud R, Urios L. Description of Palleronia rufa sp. nov., a biofilm-forming and AHL-producing Rhodobacteraceae, reclassification of Hwanghaeicola aestuarii as Palleronia aestuarii comb. nov., Maribius pontilimi as Palleronia pontilimi comb. nov., Maribius salinus as Palleronia salina comb. nov., Maribius pelagius as Palleronia pelagia comb. nov. and emended description of the genus Palleronia. Syst Appl Microbiol 2020; 43:126018. [DOI: 10.1016/j.syapm.2019.126018] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Revised: 07/22/2019] [Accepted: 07/26/2019] [Indexed: 12/15/2022]
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27
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Sun X, Chu L, Mercando E, Romero I, Hollander D, Kostka JE. Dispersant Enhances Hydrocarbon Degradation and Alters the Structure of Metabolically Active Microbial Communities in Shallow Seawater From the Northeastern Gulf of Mexico. Front Microbiol 2019; 10:2387. [PMID: 31749769 PMCID: PMC6842959 DOI: 10.3389/fmicb.2019.02387] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2019] [Accepted: 10/01/2019] [Indexed: 01/23/2023] Open
Abstract
Dispersant application is a primary emergency oil spill response strategy and yet the efficacy and unintended consequences of this approach in marine ecosystems remain controversial. To address these uncertainties, ex situ incubations were conducted to quantify the impact of dispersant on petroleum hydrocarbon (PHC) biodegradation rates and microbial community structure at as close as realistically possible to approximated in situ conditions [2 ppm v/v oil with or without dispersant, at a dispersant to oil ratio (DOR) of 1:15] in surface seawater. Biodegradation rates were not substantially affected by dispersant application at low mixing conditions, while under completely dispersed conditions, biodegradation was substantially enhanced, decreasing the overall half-life of total PHC compounds from 15.4 to 8.8 days. While microbial respiration and growth were not substantially altered by dispersant treatment, RNA analysis revealed that dispersant application resulted in pronounced changes to the composition of metabolically active microbial communities, and the abundance of nitrogen-fixing prokaryotes, as determined by qPCR of nitrogenase (nifH) genes, showed a large increase. While the Gammaproteobacteria were enriched in all treatments, the Betaproteobacteria and different families of Alphaproteobacteria predominated in the oil and dispersant treatment, respectively. Results show that mixing conditions regulate the efficacy of dispersant application in an oil slick, and the quantitative increase in the nitrogen-fixing microbial community indicates a selection pressure for nitrogen fixation in response to a readily biodegradable, nitrogen-poor substrate.
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Affiliation(s)
- Xiaoxu Sun
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA, United States.,Guangdong Key Laboratory of Agricultural Environment Pollution Integrated Control, Guangdong Institute of Eco-Environmental Science and Technology, Guangzhou, China
| | - Lena Chu
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, United States
| | - Elisa Mercando
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, United States
| | - Isabel Romero
- College of Marine Science, University of South Florida, St. Petersburg, St. Petersburg, FL, United States
| | - David Hollander
- College of Marine Science, University of South Florida, St. Petersburg, St. Petersburg, FL, United States
| | - Joel E Kostka
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA, United States.,School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, United States
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28
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Role of Caulobacter Cell Surface Structures in Colonization of the Air-Liquid Interface. J Bacteriol 2019; 201:JB.00064-19. [PMID: 31010900 DOI: 10.1128/jb.00064-19] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Accepted: 04/15/2019] [Indexed: 01/17/2023] Open
Abstract
In aquatic environments, Caulobacter spp. can be found at the boundary between liquid and air known as the neuston. I report an approach to study temporal features of Caulobacter crescentus colonization and pellicle biofilm development at the air-liquid interface and have defined the role of cell surface structures in this process. At this interface, C. crescentus initially forms a monolayer of cells bearing a surface adhesin known as the holdfast. When excised from the liquid surface, this monolayer strongly adheres to glass. The monolayer subsequently develops into a three-dimensional structure that is highly enriched in clusters of stalked cells known as rosettes. As this pellicle film matures, it becomes more cohesive and less adherent to a glass surface. A mutant strain lacking a flagellum does not efficiently reach the surface, and strains lacking type IV pili exhibit defects in organization of the three-dimensional pellicle. Strains unable to synthesize the holdfast fail to accumulate at the boundary between air and liquid and do not form a pellicle. Phase-contrast images support a model whereby the holdfast functions to trap C. crescentus cells at the air-liquid boundary. Unlike the holdfast, neither the flagellum nor type IV pili are required for C. crescentus to partition to the air-liquid interface. While it is well established that the holdfast enables adherence to solid surfaces, this study provides evidence that the holdfast has physicochemical properties that allow partitioning of nonmotile mother cells to the air-liquid interface and facilitate colonization of this microenvironment.IMPORTANCE In aquatic environments, the boundary at the air interface is often highly enriched with nutrients and oxygen. Colonization of this niche likely confers a significant fitness advantage in many cases. This study provides evidence that the cell surface adhesin known as a holdfast enables Caulobacter crescentus to partition to and colonize the air-liquid interface. Additional surface structures, including the flagellum and type IV pili, are important determinants of colonization and biofilm formation at this boundary. Considering that holdfast-like adhesins are broadly conserved in Caulobacter spp. and other members of the diverse class Alphaproteobacteria, these surface structures may function broadly to facilitate colonization of air-liquid boundaries in a range of ecological contexts, including freshwater, marine, and soil ecosystems.
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29
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Koedooder C, Stock W, Willems A, Mangelinckx S, De Troch M, Vyverman W, Sabbe K. Diatom-Bacteria Interactions Modulate the Composition and Productivity of Benthic Diatom Biofilms. Front Microbiol 2019; 10:1255. [PMID: 31231340 PMCID: PMC6561236 DOI: 10.3389/fmicb.2019.01255] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Accepted: 05/20/2019] [Indexed: 02/04/2023] Open
Abstract
Benthic diatoms are dominant primary producers in intertidal mudflats and constitute a major source of organic carbon to consumers and decomposers residing within these ecosystems. They typically form biofilms whose species richness, community composition and productivity can vary in response to environmental drivers and their interactions with other organisms (e.g., grazers). Here, we investigated whether bacteria can affect diatom community composition and vice versa, and how this could influence the biodiversity-productivity relation. Using axenic experimental communities with three common benthic diatoms (Cylindrotheca closterium, Navicula phyllepta, and Seminavis robusta), we observed an increase in algal biomass production in diatom co-cultures in comparison to monocultures. The presence of bacteria decreased the productivity of diatom monocultures while bacteria did not seem to affect the overall productivity of diatoms grown in co-cultures. The effect of bacteria on diatom growth, however, appeared to be species-specific, resulting in compositional shifts when different diatom species were grown together. The effect of the diatoms on the bacteria also proved to be species-specific as each diatom species developed a bacterial community that differed in its composition. Together, our results suggest that interactions between bacteria and diatoms residing in mudflats are a key factor in the structuring of the benthic microbial community composition and the overall functioning of that community.
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Affiliation(s)
- Coco Koedooder
- Laboratory of Protistology and Aquatic Ecology, Department of Biology, Ghent University, Ghent, Belgium
| | - Willem Stock
- Laboratory of Protistology and Aquatic Ecology, Department of Biology, Ghent University, Ghent, Belgium
| | - Anne Willems
- Laboratory of Microbiology, Department of Biochemistry and Microbiology, Ghent University, Ghent, Belgium
| | - Sven Mangelinckx
- SynBioC Research Group, Department of Green Chemistry and Technology, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
| | - Marleen De Troch
- Marine Biology, Department of Biology, Ghent University, Ghent, Belgium
| | - Wim Vyverman
- Laboratory of Protistology and Aquatic Ecology, Department of Biology, Ghent University, Ghent, Belgium
| | - Koen Sabbe
- Laboratory of Protistology and Aquatic Ecology, Department of Biology, Ghent University, Ghent, Belgium
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30
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The Biotechnological Potential of Secondary Metabolites from Marine Bacteria. JOURNAL OF MARINE SCIENCE AND ENGINEERING 2019. [DOI: 10.3390/jmse7060176] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Marine habitats are a rich source of molecules of biological interest. In particular, marine bacteria attract attention with their ability to synthesize structurally diverse classes of bioactive secondary metabolites with high biotechnological potential. The last decades were marked by numerous discoveries of biomolecules of bacterial symbionts, which have long been considered metabolites of marine animals. Many compounds isolated from marine bacteria are unique in their structure and biological activity. Their study has made a significant contribution to the discovery and production of new natural antimicrobial agents. Identifying the mechanisms and potential of this type of metabolite production in marine bacteria has become one of the noteworthy trends in modern biotechnology. This path has become not only one of the most promising approaches to the development of new antibiotics, but also a potential target for controlling the viability of pathogenic bacteria.
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31
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Abed RMM, Al Fahdi D, Muthukrishnan T. Short-term succession of marine microbial fouling communities and the identification of primary and secondary colonizers. BIOFOULING 2019; 35:526-540. [PMID: 31216872 DOI: 10.1080/08927014.2019.1622004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2019] [Revised: 05/16/2019] [Accepted: 05/17/2019] [Indexed: 06/09/2023]
Abstract
Microbial succession during the initial stages of marine biofouling has been rarely studied, especially in the Arabian Gulf. This study was undertaken to follow temporal shifts in biofouling communities in order to identify primary and secondary colonizers. Quantitative analysis revealed a significant increase in total biomass, coverage of macrofoulers, chlorophyll a concentrations, and bacterial counts with time. The relative abundance of the adnate diatoms increased with time, whereas it decreased in the case of the plocon diatoms. Non-metric multidimensional scaling (NMDS) ordination based on MiSeq data placed the bacterial communities in three distinct clusters, depending on the time of sampling. While the relative abundance of Alphaproteobacteria and Flavobacteriia decreased with time, suggesting their role as primary colonizers, the relative abundance of Actinobacteria and Planctomycetia increased with time, suggesting their role as secondary colonizers. Biofouling is a dynamic process that involves temporal quantitative and qualitative shifts in the micro- and macrofouling communities.
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Affiliation(s)
- Raeid M M Abed
- Biology Department, College of Science, Sultan Qaboos University , Al Khoud , Sultanate of Oman
| | - Dhikra Al Fahdi
- Biology Department, College of Science, Sultan Qaboos University , Al Khoud , Sultanate of Oman
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32
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Koppenhöfer S, Wang H, Scharfe M, Kaever V, Wagner-Döbler I, Tomasch J. Integrated Transcriptional Regulatory Network of Quorum Sensing, Replication Control, and SOS Response in Dinoroseobacter shibae. Front Microbiol 2019; 10:803. [PMID: 31031742 PMCID: PMC6473078 DOI: 10.3389/fmicb.2019.00803] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Accepted: 03/28/2019] [Indexed: 12/13/2022] Open
Abstract
Quorum sensing (QS) coordinates population wide gene expression of bacterial species. Highly adaptive traits like gene transfer agents (GTA), morphological heterogeneity, type 4 secretion systems (T4SS), and flagella are QS controlled in Dinoroseobacter shibae, a Roseobacter model organism. Its QS regulatory network is integrated with the CtrA phosphorelay that controls cell division in alphaproteobacteria. To elucidate the network topology, we analyzed the transcriptional response of the QS-negative D. shibae strain ΔluxI1 toward externally added autoinducer (AI) over a time period of 3 h. The signaling cascade is initiated by the CtrA phosphorelay, followed by the QS genes and other target genes, including the second messenger c-di-GMP, competence, flagella and pili. Identification of transcription factor binding sites in promoters of QS induced genes revealed the integration of QS, CtrA phosphorelay and the SOS stress response mediated by LexA. The concentration of regulatory genes located close to the origin or terminus of replication suggests that gene regulation and replication are tightly coupled. Indeed, addition of AI first stimulates and then represses replication. The restart of replication comes along with increased c-di-GMP levels. We propose a model in which QS induces replication followed by differentiation into GTA producing and non-producing cells. CtrA-activity is controlled by the c-di-GMP level, allowing some of the daughter cells to replicate again. The size of the GTA producing subpopulation is tightly controlled by QS via the AI Synthase LuxI2. Finally, induction of the SOS response allows for integration of GTA DNA into the host chromosome.
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Affiliation(s)
- Sonja Koppenhöfer
- Group Microbial Communication, Technical University of Braunschweig, Braunschweig, Germany.,Institute for Chemistry and Biology of the Marine Environment, University of Oldenburg, Oldenburg, Germany
| | - Hui Wang
- Group Microbial Communication, Technical University of Braunschweig, Braunschweig, Germany
| | - Maren Scharfe
- Group Genomic Analytics, Helmholtz Centre for Infection Research, Helmholtz Association of German Research Centers, Braunschweig, Germany
| | - Volkhard Kaever
- Research Core Unit Metabolomics, Institute of Pharmacology, Hannover Medical School, Hanover, Germany
| | - Irene Wagner-Döbler
- Group Microbial Communication, Technical University of Braunschweig, Braunschweig, Germany
| | - Jürgen Tomasch
- Group Microbial Communication, Technical University of Braunschweig, Braunschweig, Germany
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33
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Quigley LNM, Edwards A, Steen AD, Buchan A. Characterization of the Interactive Effects of Labile and Recalcitrant Organic Matter on Microbial Growth and Metabolism. Front Microbiol 2019; 10:493. [PMID: 30941109 PMCID: PMC6433851 DOI: 10.3389/fmicb.2019.00493] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Accepted: 02/26/2019] [Indexed: 11/23/2022] Open
Abstract
Geochemical models typically represent organic matter (OM) as consisting of multiple, independent pools of compounds, each accessed by microorganisms at different rates. However, recent findings indicate that organic compounds can interact within microbial metabolisms. The relevance of interactive effects within marine systems is debated and a mechanistic understanding of its complexities, including microbe-substrate relationships, is lacking. As a first step toward uncovering mediating processes, the interactive effects of distinct pools of OM on the growth and respiration of marine bacteria, individual strains and a simple, constructed community of Roseobacter lineage members were tested. Isolates were provided with natural organic matter (NOM) and different concentrations (1, 4, 40, 400 μM-C) and forms of labile OM (acetate, casamino acids, tryptone, coumarate). The microbial response to the mixed substrate regimes was assessed using viable counts and respiration in two separate experiments. Two marine bacteria and a six-member constructed community were assayed with these experiments. Both synergistic and antagonistic growth responses were evident for all strains, but all were transient. The specific substrate conditions promoting a response, and the direction of that response, varied amongst species. These findings indicate that the substrate conditions that result in OM interactive effects are both transient and species-specific and thus influenced by both the composition and metabolic potential of a microbial community.
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Affiliation(s)
- Lauren N M Quigley
- Department of Microbiology, The University of Tennessee, Knoxville, Knoxville, TN, United States
| | - Abigail Edwards
- Department of Microbiology, The University of Tennessee, Knoxville, Knoxville, TN, United States
| | - Andrew D Steen
- Department of Earth and Planetary Sciences, The University of Tennessee, Knoxville, Knoxville, TN, United States
| | - Alison Buchan
- Department of Microbiology, The University of Tennessee, Knoxville, Knoxville, TN, United States
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34
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Su Y, Tang K, Liu J, Wang Y, Zheng Y, Zhang XH. Quorum Sensing System of Ruegeria mobilis Rm01 Controls Lipase and Biofilm Formation. Front Microbiol 2019; 9:3304. [PMID: 30687283 PMCID: PMC6333666 DOI: 10.3389/fmicb.2018.03304] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2018] [Accepted: 12/19/2018] [Indexed: 01/02/2023] Open
Abstract
Quorum sensing (QS) promotes in situ extracellular enzyme (EE) activity via the exogenous signal N-acylhomoserine lactone (AHL), which facilitates marine particle degradation, but the species that engage in this regulatory mechanism remain unclear. Here, we obtained AHL-producing and AHL-degrading strains from marine particles. The strain Ruegeria mobilis Rm01 of the Roseobacter group (RBG), which was capable of both AHL producing and degrading, was chosen to represent these strains. We demonstrated that Rm01 possessed a complex QS network comprising AHL-based QS and quorum quenching (QQ) systems and autoinducer-2 (AI-2) perception system. Rm01 was able to respond to multiple exogenous QS signals through the QS network. By applying self-generated AHLs and non-self-generated AHLs and AI-2 QS signal molecules, we modulated biofilm formation and lipase production in Rm01, which reflected the coordination of bacterial metabolism with that of other species via eavesdropping on exogenous QS signals. These results suggest that R. mobilis might be one of the participators that could regulate EE activities by responding to QS signals in marine particles.
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Affiliation(s)
- Ying Su
- College of Marine Life Science, Ocean University of China, Qingdao, China.,Weifang Engineering Vocational College, Weifang, China
| | - Kaihao Tang
- College of Marine Life Science, Ocean University of China, Qingdao, China
| | - Jiwen Liu
- College of Marine Life Science, Ocean University of China, Qingdao, China.,Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Yan Wang
- College of Marine Life Science, Ocean University of China, Qingdao, China.,Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Yanfen Zheng
- College of Marine Life Science, Ocean University of China, Qingdao, China
| | - Xiao-Hua Zhang
- College of Marine Life Science, Ocean University of China, Qingdao, China.,Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
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35
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Yao Z, Yang K, Huang L, Huang X, Qiuqian L, Wang K, Zhang D. Disease outbreak accompanies the dispersive structure of shrimp gut bacterial community with a simple core microbiota. AMB Express 2018; 8:120. [PMID: 30022306 PMCID: PMC6051950 DOI: 10.1186/s13568-018-0644-x] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Accepted: 07/07/2018] [Indexed: 12/31/2022] Open
Abstract
Increasing evidence has emerged supporting a tight link between gut bacterial community and shrimp health. However, the knowledge about the variation of gut bacterial community, especially with different disease onset time, remains elusive. Here, healthy and diseased shrimps were collected at 3 disease-outbreak times (day 70, 80 and 85) to investigate the variation of gut bacterial community and its underlying ecological process with 16S rRNA gene amplicon sequencing. The gut bacterial community of diseased shrimp was distinct from the healthy one and temporally less stable, characterized by decreased alpha-diversity and dispersive structure. And its dominant ecological process experienced a transition with disease onset time, although deterministic process mainly governed the healthy gut bacterial assembly. In addition, the core microbiota of healthy shrimp gut harbored more diverse bacterial taxa with more cooperative interactions, while the diseased core microbiota showed opposite pattern with significantly higher abundance of opportunistic pathogens as well. These findings indicate that shrimp heath is highly relevant to the homeostasis of its gut bacterial community. Preservation and restoration of the bacterial community equilibrium could represent an effective strategy for shrimp disease prevention.
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36
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Bakenhus I, Voget S, Poehlein A, Brinkhoff T, Daniel R, Simon M. Genome sequence of Planktotalea frisia type strain (SH6-1 T), a representative of the Roseobacter group isolated from the North Sea during a phytoplankton bloom. Stand Genomic Sci 2018; 13:7. [PMID: 29682168 PMCID: PMC5896138 DOI: 10.1186/s40793-018-0311-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Accepted: 03/21/2018] [Indexed: 12/15/2022] Open
Abstract
Planktotalea frisia SH6-1T Hahnke et al. (Int J Syst Evol Microbiol 62:1619-24, 2012) is a planktonic marine bacterium isolated during a phytoplankton bloom from the southern North Sea. It belongs to the Roseobacter group within the alphaproteobacterial family Rhodobacteraceae. Here we describe the draft genome sequence and annotation of the type strain SH6-1T. The genome comprises 4,106,736 bp and contains 4128 protein-coding and 38 RNA genes. The draft genome sequence provides evidence for at least three extrachromosomal elements, encodes genes for DMSP utilization, quorum sensing, photoheterotrophy and a type IV secretion system. This indicates not only adaptation to a free-living lifestyle of P. frisia but points also to interactions with prokaryotic or eukaryotic organisms.
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Affiliation(s)
- Insa Bakenhus
- 1Institute for Chemistry and Biology of the Marine Environment (ICBM), University of Oldenburg, Oldenburg, Germany
| | - Sonja Voget
- 2Institute of Microbiology and Genetics, Genomic and Applied Microbiology and Göttingen Genomics Laboratory, University of Göttingen, Göttingen, Germany
| | - Anja Poehlein
- 2Institute of Microbiology and Genetics, Genomic and Applied Microbiology and Göttingen Genomics Laboratory, University of Göttingen, Göttingen, Germany
| | - Thorsten Brinkhoff
- 1Institute for Chemistry and Biology of the Marine Environment (ICBM), University of Oldenburg, Oldenburg, Germany
| | - Rolf Daniel
- 2Institute of Microbiology and Genetics, Genomic and Applied Microbiology and Göttingen Genomics Laboratory, University of Göttingen, Göttingen, Germany
| | - Meinhard Simon
- 1Institute for Chemistry and Biology of the Marine Environment (ICBM), University of Oldenburg, Oldenburg, Germany
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37
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Meyer N, Bigalke A, Kaulfuß A, Pohnert G. Strategies and ecological roles of algicidal bacteria. FEMS Microbiol Rev 2018; 41:880-899. [PMID: 28961821 DOI: 10.1093/femsre/fux029] [Citation(s) in RCA: 92] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2016] [Accepted: 05/31/2017] [Indexed: 12/21/2022] Open
Abstract
In both freshwater and marine ecosystems, phytoplankton are the most dominant primary producers, contributing substantially to aquatic food webs. Algicidal bacteria that can associate to microalgae from the phytoplankton have the capability to control the proliferation and even to lyse them. These bacteria thus play an important role in shaping species composition in pelagic environments. In this review, we discuss and categorise strategies used by algicidal bacteria for the attack on microalgae. We highlight the complex regulation of algicidal activity and defence responses that govern alga-bacteria interactions. We also discuss how algicidal bacteria impact algal physiology and metabolism and survey the existing algicidal metabolites and enzymes. The review illustrates that the ecological role of algicidal bacteria is not yet fully understood and critically discusses the challenges in obtaining ecologically relevant data.
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Affiliation(s)
- Nils Meyer
- Institute for Inorganic and Analytical Chemistry, Bioorganic Analytics, Friedrich-Schiller-Universität Jena, Lessingstrasse 8, D-07743 Jena, Germany
| | - Arite Bigalke
- Institute for Inorganic and Analytical Chemistry, Bioorganic Analytics, Friedrich-Schiller-Universität Jena, Lessingstrasse 8, D-07743 Jena, Germany
| | - Anett Kaulfuß
- Institute for Inorganic and Analytical Chemistry, Bioorganic Analytics, Friedrich-Schiller-Universität Jena, Lessingstrasse 8, D-07743 Jena, Germany
| | - Georg Pohnert
- Institute for Inorganic and Analytical Chemistry, Bioorganic Analytics, Friedrich-Schiller-Universität Jena, Lessingstrasse 8, D-07743 Jena, Germany.,Max Planck Institute for Chemical Ecology, Hans Knöll Str. 8, D-07745 Jena, Germany
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38
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Briand JF, Barani A, Garnier C, Réhel K, Urvois F, LePoupon C, Bouchez A, Debroas D, Bressy C. Spatio-Temporal Variations of Marine Biofilm Communities Colonizing Artificial Substrata Including Antifouling Coatings in Contrasted French Coastal Environments. MICROBIAL ECOLOGY 2017; 74:585-598. [PMID: 28374061 DOI: 10.1007/s00248-017-0966-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2016] [Accepted: 03/14/2017] [Indexed: 06/07/2023]
Abstract
Surface colonization in seawater first corresponds to the selection of specific microbial biofilm communities. By coupling flow cytometry, microscopy and high throughput sequencing (HTS, 454 pyrosequencing) with artificial surfaces and environmental analyses, we intend to identify the contribution of biofilm community drivers at two contrasted French sites, one temperate and eutrophic (Lorient, Atlantic coast) and the other at a mesotrophic but highly contaminated bay (Toulon, North-Western Mediterranean Sea). Microbial communities were shaped by high temperatures, salinity and lead at Toulon by but nutrients and DOC at Lorient. Coatings including pyrithione exhibited a significant decrease of their microbial densities except for nanoeukaryotes. Clustering of communities was mainly based on the surface type and secondly the site, whereas seasons appeared of less importance. The in-depth HTS revealed that γ- and α-proteobacteria, but also Bacteroidetes, dominated highly diversified bacterial communities with a relative low β-diversity. Sensitivity to biocides released by the tested antifouling coatings could be noticed at different taxonomic levels: the percentage of Bacteroidetes overall decreased with the presence of pyrithione, whereas the α/γ-proteobacteria ratio decreased at Toulon when increased at Lorient. Small diatom cells (Amphora and Navicula spp.) dominated on all surfaces, whereas site-specific sub-dominant taxa appeared clearly more sensitive to biocides. This overall approach exhibited the critical significance of surface characteristics in biofilm community shaping.
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Affiliation(s)
| | - Aude Barani
- CNRS/INSU, IRD, Institut Méditerranéen d'Océanologie (MIO), Université d'Aix-Marseille, Université de Toulon, Marseille, France
| | | | - Karine Réhel
- LBCM -EA 3883, IUEM, Université de Bretagne Sud, Lorient, France
| | - Félix Urvois
- MAPIEM-EA 4323, Université de Toulon, La Garde, France
| | | | - Agnès Bouchez
- UMR CARRTEL, INRA, Université Savoie Mont Blanc, Thonon-Les-Bains, France
| | - Didier Debroas
- Laboratoire "Microorganismes: Génome et Environnement, Clermont Université, Université Blaise Pascal, BP 10448, F-63000, Clermont-Ferrand, France
- UMR 6023, LMGE, CNRS, F-63171, Aubiere, France
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39
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Li X, Duan J, Xiao H, Li Y, Liu H, Guan F, Zhai X. Analysis of Bacterial Community Composition of Corroded Steel Immersed in Sanya and Xiamen Seawaters in China via Method of Illumina MiSeq Sequencing. Front Microbiol 2017; 8:1737. [PMID: 28955315 PMCID: PMC5601074 DOI: 10.3389/fmicb.2017.01737] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Accepted: 08/25/2017] [Indexed: 11/23/2022] Open
Abstract
Metal corrosion is of worldwide concern because it is the cause of major economic losses, and because it creates significant safety issues. The mechanism of the corrosion process, as influenced by bacteria, has been studied extensively. However, the bacterial communities that create the biofilms that form on metals are complicated, and have not been well studied. This is why we sought to analyze the composition of bacterial communities living on steel structures, together with the influence of ecological factors on these communities. The corrosion samples were collected from rust layers on steel plates that were immersed in seawater for two different periods at Sanya and Xiamen, China. We analyzed the bacterial communities on the samples by targeted 16S rRNA gene (V3–V4 region) sequencing using the Illumina MiSeq. Phylogenetic analysis revealed that the bacteria fell into 13 phylotypes (similarity level = 97%). Proteobacteria, Firmicutes and Bacteroidetes were the dominant phyla, accounting for 88.84% of the total. Deltaproteobacteria, Clostridia and Gammaproteobacteria were the dominant classes, and accounted for 70.90% of the total. Desulfovibrio spp., Desulfobacter spp. and Desulfotomaculum spp. were the dominant genera and accounted for 45.87% of the total. These genera are sulfate-reducing bacteria that are known to corrode steel. Bacterial diversity on the 6 months immersion samples was much higher than that of the samples that had been immersed for 8 years (P < 0.001, Student’s t-test). The average complexity of the biofilms from the 8-years immersion samples from Sanya was greater than those from Xiamen, but not significantly so (P > 0.05, Student’s t-test). Overall, the data showed that the rust layers on the steel plates carried many bacterial species. The bacterial community composition was influenced by the immersion time. The results of our study will be of benefit to the further studies of bacterial corrosion mechanisms and corrosion resistance.
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Affiliation(s)
- Xiaohong Li
- Key Laboratory of Marine Environmental Corrosion and Biofouling, Institute of Oceanology, Chinese Academy of SciencesQingdao, China.,College of Marine Life Sciences, Ocean University of ChinaQingdao, China
| | - Jizhou Duan
- Key Laboratory of Marine Environmental Corrosion and Biofouling, Institute of Oceanology, Chinese Academy of SciencesQingdao, China
| | - Hui Xiao
- College of Marine Life Sciences, Ocean University of ChinaQingdao, China
| | - Yongqian Li
- Key Laboratory of Marine Environmental Corrosion and Biofouling, Institute of Oceanology, Chinese Academy of SciencesQingdao, China.,College of Marine Life Sciences, Ocean University of ChinaQingdao, China
| | - Haixia Liu
- Key Laboratory of Marine Environmental Corrosion and Biofouling, Institute of Oceanology, Chinese Academy of SciencesQingdao, China
| | - Fang Guan
- Key Laboratory of Marine Environmental Corrosion and Biofouling, Institute of Oceanology, Chinese Academy of SciencesQingdao, China
| | - Xiaofan Zhai
- Key Laboratory of Marine Environmental Corrosion and Biofouling, Institute of Oceanology, Chinese Academy of SciencesQingdao, China
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40
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Monaibacterium marinum, gen. nov, sp. nov, a new member of the Alphaproteobacteria isolated from seawater of Menai Straits, Wales, UK. Int J Syst Evol Microbiol 2017; 67:3310-3317. [DOI: 10.1099/ijsem.0.002111] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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41
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Jain A, Krishnan KP. Differences in free-living and particle-associated bacterial communities and their spatial variation in Kongsfjorden, Arctic. J Basic Microbiol 2017; 57:827-838. [DOI: 10.1002/jobm.201700216] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Revised: 06/16/2017] [Accepted: 07/07/2017] [Indexed: 11/06/2022]
Affiliation(s)
- Anand Jain
- Cryobiology Laboratory; National Centre for Antarctic and Ocean Research; Vasco-da-Gama, Goa India
| | - Kottekkatu P. Krishnan
- Cryobiology Laboratory; National Centre for Antarctic and Ocean Research; Vasco-da-Gama, Goa India
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42
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Beyersmann PG, Tomasch J, Son K, Stocker R, Göker M, Wagner-Döbler I, Simon M, Brinkhoff T. Dual function of tropodithietic acid as antibiotic and signaling molecule in global gene regulation of the probiotic bacterium Phaeobacter inhibens. Sci Rep 2017; 7:730. [PMID: 28389641 PMCID: PMC5429656 DOI: 10.1038/s41598-017-00784-7] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Accepted: 03/13/2017] [Indexed: 01/12/2023] Open
Abstract
Antibiotics are typically regarded as microbial weapons, but whereas their function at concentrations lethal for bacteria is often well characterized, the role of antibiotics at much lower concentrations as possibly found under natural conditions remains poorly understood. By using whole-transcriptome analyses and phenotypic screenings of the marine bacterium Phaeobacter inhibens we found that the broad-spectrum antibiotic tropodithietic acid (TDA) causes the same regulatory effects in quorum sensing (QS) as the common signaling molecule N-acyl-homoserine lactone (AHL) at concentrations 100-fold lower than the minimal inhibitory concentration against bacteria. Our results show that TDA has a significant impact on the expression of ~10% of the total genes of P. inhibens, in the same manner as the AHL. Furthermore, TDA needs the AHL associated LuxR-type transcriptional regulator, just as the AHL molecule. Low concentrations of antibiotics can obviously have a strong influence on the global gene expression of the bacterium that produces it and drastically change the metabolism and behaviour of the bacterium. For P. inhibens this includes motility, biofilm formation and antibiotic production, all important for settlement on new host-associated surfaces. Our results demonstrate that bacteria can produce antibiotics not only to antagonise other bacteria, but also to mediate QS like endogenous AHL molecules.
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Affiliation(s)
- Paul G Beyersmann
- Institute for Chemistry and Biology of the Marine Environment (ICBM), University of Oldenburg, 26129, Oldenburg, Germany
| | - Jürgen Tomasch
- Helmholtz Centre for Infection Research, 38124, Braunschweig, Germany
| | - Kwangmin Son
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Roman Stocker
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- Institute for Environmental Engineering, Department of Civil, Environmental and Geomatic Engineering, Eidgenössische Technische Hochschule (ETH) Zürich, Zurich, 8093, Switzerland
| | - Markus Göker
- Leibniz-Institute DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, 38124, Braunschweig, Germany
| | | | - Meinhard Simon
- Institute for Chemistry and Biology of the Marine Environment (ICBM), University of Oldenburg, 26129, Oldenburg, Germany
| | - Thorsten Brinkhoff
- Institute for Chemistry and Biology of the Marine Environment (ICBM), University of Oldenburg, 26129, Oldenburg, Germany.
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Anjum K, Abbas SQ, Akhter N, Shagufta BI, Shah SAA, Hassan SSU. Emerging biopharmaceuticals from bioactive peptides derived from marine organisms. Chem Biol Drug Des 2017; 90:12-30. [PMID: 28004491 DOI: 10.1111/cbdd.12925] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Revised: 10/27/2016] [Accepted: 12/11/2016] [Indexed: 12/16/2022]
Abstract
Biologically active natural products are spontaneous medicinal entrants, which encourage synthetic access for enhancing and supporting drug discovery and development. Marine bioactive peptides are considered as a rich source of natural products that may provide long-term health, in addition to many prophylactic and curative medicinal drug treatments. The large literature concerning marine peptides has been collected, which shows high potential of nutraceutical and therapeutic efficacy encompassing wide spectra of bioactivities against a number of infection-causing agents. Their antimicrobial, antimalarial, antitumor, antiviral, and cardioprotective actions have achieved the attention of the pharmaceutical industry toward new design of drug formulations, for treatment and prevention of several infections. However, the mechanism of action of many peptide molecules has been still untapped. So in this regard, this paper reviews several peptide compounds by which they interfere with human pathogenesis. This knowledge is one of the key tools to be understood especially for the biotransformation of biomolecules into targeted medicines. The fact that different diseases have the capability to fight at different sites inside the body can lead to a new wave of increasing the chances to produce targeted medicines.
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Affiliation(s)
- Komal Anjum
- Ocean College, Zhejiang University, Hangzhou, China
| | - Syed Qamar Abbas
- Faculty of Pharmacy, Gomal University, D.I. Khan, Khyber-Pakhtunkhwa, Pakistan
| | | | - Bibi Ibtesam Shagufta
- Department of Zoology, Kohat University of Science and Technology (KUST), D.I. Khan, Khyber-Pakhtunkhwa, Pakistan
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A Rhizobiales-Specific Unipolar Polysaccharide Adhesin Contributes to Rhodopseudomonas palustris Biofilm Formation across Diverse Photoheterotrophic Conditions. Appl Environ Microbiol 2017; 83:AEM.03035-16. [PMID: 27986718 DOI: 10.1128/aem.03035-16] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Accepted: 12/08/2016] [Indexed: 12/25/2022] Open
Abstract
Bacteria predominantly exist as members of surfaced-attached communities known as biofilms. Many bacterial species initiate biofilms and adhere to each other using cell surface adhesins. This is the case for numerous ecologically diverse Alphaprotebacteria, which use polar exopolysaccharide adhesins for cell-cell adhesion and surface attachment. Here, we show that Rhodopseudomonas palustris, a metabolically versatile member of the alphaproteobacterial order Rhizobiales, contains a functional unipolar polysaccharide (UPP) biosynthesis gene cluster. Deletion of genes predicted to be critical for UPP biosynthesis and export abolished UPP production. We also found that R. palustris uses UPP to mediate biofilm formation across diverse photoheterotrophic growth conditions, wherein light and organic substrates are used to support growth. However, UPP was less important for biofilm formation during photoautotrophy, where light and CO2 support growth, and during aerobic respiration with organic compounds. Expanding our analysis beyond R. palustris, we examined the phylogenetic distribution and genomic organization of UPP gene clusters among Rhizobiales species that inhabit diverse niches. Our analysis suggests that UPP is a conserved ancestral trait of the Rhizobiales but that it has been independently lost multiple times during the evolution of this clade, twice coinciding with adaptation to intracellular lifestyles within animal hosts. IMPORTANCE Bacteria are ubiquitously found as surface-attached communities and cellular aggregates in nature. Here, we address how bacterial adhesion is coordinated in response to diverse environments using two complementary approaches. First, we examined how Rhodopseudomonas palustris, one of the most metabolically versatile organisms ever described, varies its adhesion to surfaces in response to different environmental conditions. We identified critical genes for the production of a unipolar polysaccharide (UPP) and showed that UPP is important for adhesion when light and organic substrates are used for growth. Looking beyond R. palustris, we performed the most comprehensive survey to date on the conservation of UPP biosynthesis genes among a group of closely related bacteria that occupy diverse niches. Our findings suggest that UPP is important for free-living and plant-associated lifestyles but dispensable for animal pathogens. Additionally, we propose guidelines for classifying the adhesins produced by various Alphaprotebacteria, facilitating future functional and comparative studies.
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45
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Direct Heme Uptake by Phytoplankton-Associated Roseobacter Bacteria. mSystems 2017; 2:mSystems00124-16. [PMID: 28083564 PMCID: PMC5225302 DOI: 10.1128/msystems.00124-16] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Accepted: 12/09/2016] [Indexed: 01/19/2023] Open
Abstract
Ecosystem productivity in large regions of the surface ocean is fueled by iron that has been microbially regenerated from biomass. Currently, the specific microbes and molecules that mediate the transfer of recycled iron between microbial trophic levels remain largely unknown. We characterized a marine bacterial heme transporter and verified its role in acquiring heme, an abundant iron-containing enzyme cofactor. We present evidence that after host cell lysis, phytoplankton-associated bacteria directly extract heme and hemoproteins from algal cellular debris in order to fulfill their iron requirements and that the regulation of this process may be modulated by host cues. Direct heme transport, in contrast to multistep extracellular processing of hemoproteins, may allow certain phytoplankton-associated bacteria to rapidly extract iron from decaying phytoplankton, thus efficiently recycling cellular iron into the wider microbial loop. Iron is an essential micronutrient and can limit the growth of both marine phytoplankton and heterotrophic bacterioplankton. In this study, we investigated the molecular basis of heme transport, an organic iron acquisition pathway, in phytoplankton-associated Roseobacter bacteria and explored the potential role of bacterial heme uptake in the marine environment. We searched 153 Roseobacter genomes and found that nearly half contained putative complete heme transport systems with nearly the same synteny. We also examined a publicly available coculture transcriptome and found that Roseobacter strain Sulfitobacter sp. strain SA11 strongly downregulated a putative heme transport gene cluster during mutualistic growth with a marine diatom, suggesting that the regulation of heme transport might be influenced by host cues. We generated a mutant of phytoplankton-associated Roseobacter strain Ruegeria sp. strain TM1040 by insertionally inactivating its homolog of the TonB-dependent heme transporter hmuR and confirmed the role of this gene in the uptake of heme and hemoproteins. We performed competition experiments between iron-limited wild-type and mutant TM1040 strains and found that the wild type maintains a growth advantage when competing with the mutant for iron compounds derived solely from lysed diatom cells. Heme transport systems were largely absent from public marine metagenomes and metatranscriptomes, suggesting that marine bacteria with the potential for heme transport likely have small standing populations in the free-living bacterioplankton. Heme transport is likely a useful strategy for phytoplankton-associated bacteria because it provides direct access to components of the host intracellular iron pool after lysis. IMPORTANCE Ecosystem productivity in large regions of the surface ocean is fueled by iron that has been microbially regenerated from biomass. Currently, the specific microbes and molecules that mediate the transfer of recycled iron between microbial trophic levels remain largely unknown. We characterized a marine bacterial heme transporter and verified its role in acquiring heme, an abundant iron-containing enzyme cofactor. We present evidence that after host cell lysis, phytoplankton-associated bacteria directly extract heme and hemoproteins from algal cellular debris in order to fulfill their iron requirements and that the regulation of this process may be modulated by host cues. Direct heme transport, in contrast to multistep extracellular processing of hemoproteins, may allow certain phytoplankton-associated bacteria to rapidly extract iron from decaying phytoplankton, thus efficiently recycling cellular iron into the wider microbial loop.
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46
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Rolland JL, Stien D, Sanchez-Ferandin S, Lami R. Quorum Sensing and Quorum Quenching in the Phycosphere of Phytoplankton: a Case of Chemical Interactions in Ecology. J Chem Ecol 2016; 42:1201-1211. [PMID: 27822708 DOI: 10.1007/s10886-016-0791-y] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Revised: 09/20/2016] [Accepted: 10/05/2016] [Indexed: 12/28/2022]
Abstract
The interactions between bacteria and phytoplankton regulate many important biogeochemical reactions in the marine environment, including those in the global carbon, nitrogen, and sulfur cycles. At the microscopic level, it is now well established that important consortia of bacteria colonize the phycosphere, the immediate environment of phytoplankton cells. In this microscale environment, abundant bacterial cells are organized in a structured biofilm, and exchange information through the diffusion of small molecules called semiochemicals. Among these processes, quorum sensing plays a particular role as, when a sufficient abundance of cells is reached, it allows bacteria to coordinate their gene expression and physiology at the population level. In contrast, quorum quenching mechanisms are employed by many different types of microorganisms that limit the coordination of antagonistic bacteria. This review synthesizes quorum sensing and quorum quenching mechanisms evidenced to date in the phycosphere, emphasizing the implications that these signaling systems have for the regulation of bacterial communities and their activities. The diversity of chemical compounds involved in these processes is examined. We further review the bacterial functions regulated in the phycosphere by quorum sensing, which include biofilm formation, nutrient acquisition, and emission of algaecides. We also discuss quorum quenching compounds as antagonists of quorum sensing, their function in the phycosphere, and their potential biotechnological applications. Overall, the current state of the art demonstrates that quorum sensing and quorum quenching regulate a balance between a symbiotic and a parasitic way of life between bacteria and their phytoplankton host.
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Affiliation(s)
- Jean Luc Rolland
- Interactions-Hôtes-Pathogènes-Environnements (IHPE), Ifremer, CNRS, UPVD, Université de Montpellier, UMR 5244, 34090, Montpellier, France
| | - Didier Stien
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, Laboratoire de Biodiversité et Biotechnologies Microbiennes (LBBM), Observatoire Océanologique, Banyuls-sur-Mer, France
| | - Sophie Sanchez-Ferandin
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, Laboratoire de Biologie Intégrative des Organismes Marins (BIOM), Observatoire Océanologique, Banyuls-sur-Mer, France
| | - Raphaël Lami
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, Laboratoire de Biodiversité et Biotechnologies Microbiennes (LBBM), Observatoire Océanologique, Banyuls-sur-Mer, France.
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47
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Mitulla M, Dinasquet J, Guillemette R, Simon M, Azam F, Wietz M. Response of bacterial communities from California coastal waters to alginate particles and an alginolytic Alteromonas macleodii strain. Environ Microbiol 2016; 18:4369-4377. [PMID: 27059936 DOI: 10.1111/1462-2920.13314] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 03/23/2016] [Indexed: 11/29/2022]
Abstract
Alginate is a major cell wall polysaccharide from marine macroalgae and nutrient source for heterotrophic bacteria. Alginate can form gel particles in contact with divalent cations as found in seawater. Here, we tested the hypothesis that alginate gel particles serve as carbon source and microhabitat for marine bacteria by adding sterile alginate particles to microcosms with seawater from coastal California, a habitat rich in alginate-containing macroalgae. Alginate particles were rapidly colonized and degraded, with three- to eightfold higher bacterial abundances and production among alginate particle-associated (PA) bacteria. 16S rRNA gene amplicon sequencing showed that alginate PA bacteria were enriched in OTUs related to Cryomorphaceae, Saprospiraceae (Bacteroidetes) and Phaeobacter (Alphaproteobacteria) towards the end of the experiment. In microcosms amended with alginate particles and the proficient alginolytic bacterium Alteromonas macleodii strain 83-1, this strain dominated the community and outcompeted Cryomorphaceae, Saprospiraceae and Phaeobacter, and PA hydrolytic activities were over 50% higher. Thus, alginolytic activity by strain 83-1 did not benefit non-alginolytic strains by cross-feeding on alginate hydrolysis or other metabolic products. Considering the global distribution and extensive biomass of alginate-containing macroalgae, the observed bacterial dynamics associated with the utilization and remineralization of alginate microhabitats promote the understanding of carbon cycling in macroalgae-rich waters worldwide.
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Affiliation(s)
- Maximilian Mitulla
- Institute for Chemistry and Biology of the Marine Environment, University of Oldenburg, 26129 Oldenburg, Germany
| | - Julie Dinasquet
- Marine Biology Research Division, Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, 92037, USA.,Laboratoire d'Oceanographie Microbienne (LOMIC), Observatoire Océanologique de Banyuls sur mer, Sorbonne Universités, UPMC, France
| | - Ryan Guillemette
- Marine Biology Research Division, Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, 92037, USA
| | - Meinhard Simon
- Institute for Chemistry and Biology of the Marine Environment, University of Oldenburg, 26129 Oldenburg, Germany
| | - Farooq Azam
- Marine Biology Research Division, Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, 92037, USA
| | - Matthias Wietz
- Institute for Chemistry and Biology of the Marine Environment, University of Oldenburg, 26129 Oldenburg, Germany
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Cruz-López R, Maske H. The Vitamin B1 and B12 Required by the Marine Dinoflagellate Lingulodinium polyedrum Can be Provided by its Associated Bacterial Community in Culture. Front Microbiol 2016; 7:560. [PMID: 27199906 PMCID: PMC4858720 DOI: 10.3389/fmicb.2016.00560] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Accepted: 04/04/2016] [Indexed: 11/13/2022] Open
Abstract
In this study we established the B1 and B12 vitamin requirement of the dinoflagellate Lingulodinium polyedrum and the vitamin supply by its associated bacterial community. In previous field studies the B1 and B12 demand of this species was suggested but not experimentally verified. When the axenic vitamin un-supplemented culture (B-ns) of L. polyedrum was inoculated with a coastal bacterial community, the dinoflagellate’s vitamin growth limitation was overcome, reaching the same growth rates as the culture growing in vitamin B1B7B12-supplemented (B-s) medium. Measured B12 concentrations in the B-s and B-ns cultures were both higher than typical coastal concentrations and B12 in the B-s culture was higher than in the B-ns culture. In both B-s and B-ns cultures, the probability of dinoflagellate cells having bacteria attached to the cell surface was similar and in both cultures an average of six bacteria were attached to each dinoflagellate cell. In the B-ns culture the free bacterial community showed significantly higher cell abundance suggesting that unattached bacteria supplied the vitamins. The fluorescence in situ hybridization (FISH) protocol allowed the quantification and identification of three bacterial groups in the same samples of the free and attached epibiotic bacteria for both treatments. The relative composition of these groups was not significantly different and was dominated by Alphaproteobacteria (>89%). To complement the FISH counts, 16S rDNA sequencing targeting the V3–V4 regions was performed using Illumina-MiSeq technology. For both vitamin amendments, the dominant group found was Alphaproteobacteria similar to FISH, but the percentage of Alphaproteobacteria varied between 50 and 95%. Alphaproteobacteria were mainly represented by Marivita sp., a member of the Roseobacter clade, followed by the Gammaproteobacterium Marinobacter flavimaris. Our results show that L. polyedrum is a B1 and B12 auxotroph, and acquire both vitamins from the associated bacterial community in sufficient quantity to sustain the maximum growth rate.
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Affiliation(s)
- Ricardo Cruz-López
- Oceanografía Biológica, Centro de Investigación Científica y de Educación Superior de Ensenada Ensenada, Mexico
| | - Helmut Maske
- Oceanografía Biológica, Centro de Investigación Científica y de Educación Superior de Ensenada Ensenada, Mexico
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Vanucci S, Guidi F, Pistocchi R, Long RA. Phylogenetic structure of bacterial assemblages co-occurring with Ostreopsis cf. ovata bloom. HARMFUL ALGAE 2016; 55:259-271. [PMID: 28073540 DOI: 10.1016/j.hal.2016.04.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2016] [Revised: 04/05/2016] [Accepted: 04/06/2016] [Indexed: 06/06/2023]
Abstract
Extensive blooms of the toxic epiphytic/benthic dinoflagellate Ostreopsis cf. ovata are being reported with increasing frequency and spatial distribution in temperate coastal regions including the Mediterranean. These blooms are of human and environmental health concern due to the production of isobaric palytoxin and a wide range of ovatoxins by Ostreopsis cf. ovata. Bacterial-microalgal interactions are important regulators in algal bloom dynamics and potentially toxin dynamics. This study investigated the bacterial assemblages co-occurring with O. cf. ovata (OA) and from ambient seawaters (SW) during the early and peak phases of bloom development in NW Adriatic Sea. Fractions of the bacterial assemblages co-occurring with O. cf. ovata (OA) and more closely associated to the mucilage layer (LA) embedding O. cf. ovata cells were also reported. In total, 14 bacterial phyla were detected by targeted 454 pyrosequencing of the 16S rRNA gene. The dominant bacterial phyla in the OA assemblages were Proteobacteria and Bacteroidetes; while at the class level, Alphaproteobacteria were the most abundant (83 and 66%, relative abundance, early and peak bloom phases), followed by Flavobacteria (7 and 19%, early and peak phases). Actinobacteria and Cyanobacteria were of minor importance (<5% of the relative bacterial abundance each). Gammaproteobacteria showed a notably presence in OA assemblage only at the early phase of the bloom (genus Haliea, 13%). The Alphaproteobacteria were predominately composed by the genera Ruegeria, Jannaschia and Erythrobacter which represented about half of the total phylotypes' contribution of OA at both early and peak phases of the O. cf. ovata bloom, suggesting interactions between this consortium and the microalga. Moreover, the highest contribution of Ruegeria (30% of the total phylotypes) was observed at the early phase of the bloom in LA assemblage. Microbial assemblages associated with the ambient seawaters while being also dominated by Alphaproteobacteria and Flavobacteria were partially distinct from those associated with O. cf. ovata due to the presence of genera almost not retrieved in the latter assemblages.
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Affiliation(s)
- Silvana Vanucci
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences (ChiBioFarAm), University of Messina, Viale Ferdinando Stagno d'Alcontres 31, 98166 S. Agata, Messina, Italy.
| | - Flavio Guidi
- Department of Biological, Geological and Environmental Sciences (BiGeA), University of Bologna, Via S'Alberto 163, 48123 Ravenna, Italy
| | - Rossella Pistocchi
- Department of Biological, Geological and Environmental Sciences (BiGeA), University of Bologna, Via S'Alberto 163, 48123 Ravenna, Italy
| | - Richard A Long
- Department of Biological Sciences, Florida A&M University, Tallahassee, FL 32307, United States
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Investigation of the Genetics and Biochemistry of Roseobacticide Production in the Roseobacter Clade Bacterium Phaeobacter inhibens. mBio 2016; 7:e02118. [PMID: 27006458 PMCID: PMC4807370 DOI: 10.1128/mbio.02118-15] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Roseobacter clade bacteria are abundant in surface waters and are among the most metabolically diverse and ecologically significant species. This group includes opportunistic symbionts that associate with micro- and macroalgae. We have proposed that one representative member, Phaeobacter inhibens, engages in a dynamic symbiosis with the microalga Emiliania huxleyi. In one phase, mutualistically beneficial molecules are exchanged, including the Roseobacter-produced antibiotic tropodithietic acid (TDA), which is thought to protect the symbiotic interaction. In an alternative parasitic phase, triggered by algal senescence, the bacteria produce potent algaecides, the roseobacticides, which kill the algal host. Here, we employed genetic and biochemical screens to identify the roseobacticide biosynthetic gene cluster. By using a transposon mutagenesis approach, we found that genes required for TDA synthesis—the tda operon and paa catabolon—are also necessary for roseobacticide production. Thus, in contrast to the one-cluster–one-compound paradigm, the tda gene cluster can generate two sets of molecules with distinct structures and bioactivities. We further show that roseobacticide production is quorum sensing regulated via an N-acyl homoserine lactone signal (3-OH–C10-HSL). To ensure tight regulation of algaecide production, and thus of a lifestyle switch from mutualism to parasitism, roseobacticide biosynthesis necessitates the presence of both an algal senescence molecule and a quorum sensing signal. Marine Roseobacter species are abundant in the oceans and engage in symbiotic interactions with microscopic algae. One member, P. inhibens, produces the antibiotic TDA and a growth hormone thought to protect and promote algal growth. However, in the presence of molecules released by senescing algae, the bacteria produce potent algaecides, the roseobacticides, which kill the host. We examined the regulatory networks and biosynthetic genes required for roseobacticide production. We found that P. inhibens uses largely the same set of genes for production of both TDA and roseobacticides, thus providing a rare case in which one gene cluster synthesizes two structurally and functionally distinct molecules. Moreover, we found roseobacticide production to be regulated by quorum sensing. Thus, two small molecules, the algal metabolite and the quorum-sensing signal, ensure tight control in the production of roseobacticides. These results highlight the role of small molecules in regulating microbial symbioses.
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