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Yousaf T, Saleem F, Andleeb S, Ali M, Farhan Ul Haque M. Methylotrophic bacteria from rice paddy soils: mineral-nitrogen-utilizing isolates richness in bulk soil and rhizosphere. World J Microbiol Biotechnol 2024; 40:188. [PMID: 38702590 DOI: 10.1007/s11274-024-04000-3] [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: 01/05/2024] [Accepted: 04/22/2024] [Indexed: 05/06/2024]
Abstract
Methanol, the second most abundant volatile organic compound, primarily released from plants, is a major culprit disturbing atmospheric chemistry. Interestingly, ubiquitously found methanol-utilizing bacteria, play a vital role in mitigating atmospheric methanol effects. Despite being extensively characterized, the effect of nitrogen sources on the richness of methanol-utilizers in the bulk soil and rhizosphere is largely unknown. Therefore, the current study was planned to isolate, characterize and explore the richness of cultivable methylotrophs from the bulk soil and rhizosphere of a paddy field using media with varying nitrogen sources. Our data revealed that more genera of methylotrophs, including Methylobacterium, Ancylobacter, Achromobacter, Xanthobacter, Moraxella, and Klebsiella were enriched with the nitrate-based medium compared to only two genera, Hyphomicrobium and Methylobacterium, enriched with the ammonium-based medium. The richness of methylotrophic bacteria also differed substantially in the bulk soil as compared to the rhizosphere. Growth characterization revealed that majority of the newly isolated methanol-utilizing strains in this study exhibited better growth at 37 °C instead of 30 or 45 °C. Moreover, Hyphomicrobium sp. FSA2 was the only strain capable of utilizing methanol even at elevated temperature 45 °C, showing its adaptability to a wide range of temperatures. Differential carbon substrate utilization profiling revealed the facultative nature of all isolated methanol-utilizer strains with Xanthobacter sp. TS3, being an important methanol-utilizer capable of degrading toxic compounds such as acetone and ethylene glycol. Overall, our study suggests the role of nutrients and plant-microbial interaction in shaping the composition of methanol-utilizers in terrestrial environment.
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Affiliation(s)
- Tabassum Yousaf
- School of Biological Sciences, University of the Punjab, Lahore, 54590, Pakistan
| | - Fatima Saleem
- School of Biological Sciences, University of the Punjab, Lahore, 54590, Pakistan
| | - Sahar Andleeb
- School of Biological Sciences, University of the Punjab, Lahore, 54590, Pakistan
| | - Muhammad Ali
- Faculty of Agriculture Sciences, University of the Punjab, Lahore, 54590, Pakistan
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Synaptic effects of IL-1β and CRF in the central amygdala after protracted alcohol abstinence in male rhesus macaques. Neuropsychopharmacology 2022; 47:847-856. [PMID: 34837077 PMCID: PMC8882167 DOI: 10.1038/s41386-021-01231-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 10/14/2021] [Accepted: 11/02/2021] [Indexed: 12/21/2022]
Abstract
A major barrier to remission from an alcohol use disorder (AUD) is the continued risk of relapse during abstinence. Assessing the neuroadaptations after chronic alcohol and repeated abstinence is important to identify mechanisms that may contribute to relapse. In this study, we used a rhesus macaque model of long-term alcohol use and repeated abstinence, providing a platform to extend mechanistic findings from rodents to primates. The central amygdala (CeA) displays elevated GABA release following chronic alcohol in rodents and in abstinent male macaques, highlighting this neuroadaptation as a conserved mechanism that may underlie excessive alcohol consumption. Here, we determined circulating interleukin-1β (IL-1β) levels, CeA transcriptomic changes, and the effects of IL-1β and corticotropin releasing factor (CRF) signaling on CeA GABA transmission in male controls and abstinent drinkers. While no significant differences in peripheral IL-1β or the CeA transcriptome were observed, pathway analysis identified several canonical immune-related pathways. We addressed this potential dysregulation of CeA immune signaling in abstient drinkers with an electrophysiological approach. We found that IL-1β decreased CeA GABA release in controls while abstinent drinkers were less sensitive to IL-1β's effects, suggesting adaptations in the neuromodulatory role of IL-1β. In contrast, CRF enhanced CeA GABA release similarly in controls and abstinent drinkers, consistent with rodent studies. Notably, CeA CRF expression was inversely correlated with intoxication, suggesting that CRF levels during abstinence may predict future intoxication. Together, our findings highlight conserved and divergent actions of chronic alcohol on neuroimmune and stress signaling on CeA GABA transmission across rodents and macaques.
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Possible benefits of exogenous melatonin for individuals on dialysis: a narrative review on potential mechanisms and clinical implications. Naunyn Schmiedebergs Arch Pharmacol 2021; 394:1599-1611. [PMID: 34097094 DOI: 10.1007/s00210-021-02099-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Accepted: 05/06/2021] [Indexed: 10/21/2022]
Abstract
Prevention of oxidative stress and inflammation in chronic kidney disease patients (CKD) on dialysis may reduce dialysis-associated complications. Administration of powerful antioxidants may improve the consequences of peritoneal dialysis (PD) and hemodialysis (HD). This narrative review aimed to show the potential therapeutic effects of melatonin (MLT) on the consequences of CKD patients receiving HD or PD. The results of preclinical and clinical studies have proven that CKD and dialysis are accompanied by reduced endogenous MLT levels and related complications such as sleep disorders. Enhanced oxidative stress, inflammation, cellular damages, and renal fibrosis, along with dysregulation of the renin-angiotensin system (RAS), have been observed in CKD and patients on dialysis. Results of studies have revealed that the restoration of MLT via the exogenous source may regulate oxidative stress, inflammation, and RAS functions, inhibit fibrosis, and improve complications in patients with long-term dialysis patients. In summary, treatment of patients with CKD and dialysis with exogenous MLT is suggested as a practical approach in reducing the outcomes and improving the quality of life in patients via antioxidant, anti-inflammatory, and anti-fibrotic signaling pathways. Therefore, this hormone can be considered in clinical practice to manage dialysis-related complications.
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Lawrence JR, Winkler M, Neu TR. Multi-Parameter Laser Imaging Reveals Complex Microscale Biofilm Matrix in a Thick (4,000 μm) Aerobic Methanol Oxidizing Community. Front Microbiol 2018; 9:2186. [PMID: 30333795 PMCID: PMC6176653 DOI: 10.3389/fmicb.2018.02186] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Accepted: 08/27/2018] [Indexed: 11/13/2022] Open
Abstract
Although methanol has frequently been used as an inexpensive supplementary carbon source to support treatment processes, knowledge of the resultant microbial biofilms, their 3D architecture, microenvironments, exopolymer chemistry and populations remains limited. We supplied methanol as a supplementary carbon source to biofilms developing in rotating annular reactors. Analysis of circulation waters (1.0 l d-1) indicated that dissolved organic carbon was reduced by 25%, NO3-nitrogen by 95%, and total phosphorus by 70%. Analyses of populations using culture based techniques and fluorescence in situ hybridization indicated enrichment of nitrifiers, denitrifiers, and methylotrophic bacteria relative to reference biofilms not receiving methanol. The biofilms that developed were up to 4,000 μm thick. Staining with fluor conjugated lectins in combination with nucleic acid stains, revealed the presence of discrete bacterial cells inside complex globular polymeric structures. These structures were in turn surrounded by an interstitial polymer containing a variety of bacterial cell types. The globular structures bound FITC-conjugated lectins, from Canavalia ensiformis and Ulex europeaus. The FITC-lectin of Phaseolus vulgaris bound the surface of the globular structures and more generally within the matrix. Chemical analyses of the polymer paralleled the results of lectin analyses indicating that the dominant neutral sugars were glucose, galactose, mannose, rhamnose, with fucose and ribose as minor constituents. Amino sugars were not detected. Dual channel imaging with pH sensitive probes indicated that pH gradients from pH 4 to 7 occurred across the globular microcolonies. Critically for the maintenance of aerobic conditions throughout the thick biofilm it was extensively penetrated by a fine fissure network revealed by the location of fluorescent latex microbeads as detected by confocal laser scanning microscopy. Microelectrode studies confirmed the absence of any detectable Eh gradients within the biofilm. However, mobility of various size-fractionated fluorescent probes indicated that the basal region was only penetrated by the lowest molecular weight probes with a hydrated radius of 2.2 nm or less. These observations indicate the selection of a unique, thick (>4,000 μm) microbial community in which a self-organized architecture promotes the maintenance of optimal conditions and metabolism throughout the biofilm community.
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Affiliation(s)
- John R Lawrence
- Environment and Climate Change Canada, Saskatoon, SK, Canada
| | | | - Thomas R Neu
- Department of River Ecology, Helmholtz Centre for Environmental Research, Magdeburg, Germany
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Rochman FF, Kim JJ, Rijpstra WIC, Sinninghe Damsté JS, Schumann P, Verbeke TJ, Dunfield PF. Oleiharenicola alkalitolerans gen. nov., sp. nov., a new member of the phylum Verrucomicrobia isolated from an oilsands tailings pond. Int J Syst Evol Microbiol 2018; 68:1078-1084. [PMID: 29461179 DOI: 10.1099/ijsem.0.002624] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A novel member of the phylum Verrucomicrobia was isolated from an oilsands tailings pond in Alberta, Canada. Cells of isolate NVTT are Gram-negative, strictly aerobic, non-pigmented, non-motile cocci to diplococci 0.5-1.0 µm in diameter. The bacterium is neutrophilic (optimum pH 6.0-8.0) but alkalitolerant, capable of growth between pH 5.5 and 11.0. The temperature range for growth is 15-40 °C (optimum 25-37 °C). Carbon and energy sources include sugars and organic acids. Nitrogen sources include nitrate, urea, l-glycine, l-alanine, l-proline and l-serine. Does not fix atmospheric nitrogen. Does not require NaCl and is inhibited at NaCl concentrations above 3.0 % (w/v). The DNA G+C content of strain NVTT, based on a draft genome sequence, is 66.1 mol%. MK-6 and MK-7 are the major respiratory quinones. Major cellular fatty acids are anteiso-C15 : 0 and iso-C15 : 0. Phylogenetic analysis of 16S rRNA gene sequences revealed that the strain belongs to the family Opitutaceae of the phylum Verrucomicrobia. The most closely related validated species is Opitutus terrae (93.7 % 16S rRNA gene sequence identity to its type strain PB90-1T). Based on genotypic, phenotypic and chemotaxonomic characteristics, it was concluded that this strain represents a novel genus and species, for which the name Oleiharenicola alkalitolerans gen. nov., sp. nov. is proposed. The type strain of this novel species is NVTT (=ATCC BAA-2697T;=DSM 29249T).
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Affiliation(s)
- Fauziah F Rochman
- Department of Biological Sciences, University of Calgary, Calgary, Canada
| | - Joong-Jae Kim
- Department of Biological Sciences, University of Calgary, Calgary, Canada
| | - W Irene C Rijpstra
- Department of Marine Microbiology and Biogeochemistry, Utrecht University, NIOZ Royal Netherlands Institute for Sea Research, P.O. Box 59, 1790 AB, Den Burg, Texel, The Netherlands
| | - Jaap S Sinninghe Damsté
- Department of Marine Microbiology and Biogeochemistry, Utrecht University, NIOZ Royal Netherlands Institute for Sea Research, P.O. Box 59, 1790 AB, Den Burg, Texel, The Netherlands.,Faculty of Geosciences, Department of Earth Sciences, Utrecht University, P.O. Box 80.021, 3508 TA Utrecht, The Netherlands
| | - Peter Schumann
- Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
| | - Tobin J Verbeke
- Department of Biological Sciences, University of Calgary, Calgary, Canada
| | - Peter F Dunfield
- Department of Biological Sciences, University of Calgary, Calgary, Canada
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Kappler U, Nouwens AS. Metabolic adaptation and trophic strategies of soil bacteria-C1- metabolism and sulfur chemolithotrophy in Starkeya novella. Front Microbiol 2013; 4:304. [PMID: 24146664 PMCID: PMC3797975 DOI: 10.3389/fmicb.2013.00304] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2013] [Accepted: 09/23/2013] [Indexed: 11/22/2022] Open
Abstract
The highly diverse and metabolically versatile microbial communities found in soil environments are major contributors to the global carbon, nitrogen, and sulfur cycles. We have used a combination of genome -based pathway analysis with proteomics and gene expression studies to investigate metabolic adaptation in a representative of these bacteria, Starkeya novella, which was originally isolated from agricultural soil. This bacterium was the first facultative sulfur chemolithoautotroph that was isolated and it is also able to grow with methanol and on over 39 substrates as a heterotroph. However, using glucose, fructose, methanol, thiosulfate as well as combinations of the carbon compounds with thiosulfate as growth substrates we have demonstrated here that contrary to the previous classification, S. novella is not a facultative sulfur chemolitho- and methylotroph, as the enzyme systems required for these two growth modes are always expressed at high levels. This is typical for key metabolic pathways. In addition enzymes for various pathways of carbon dioxide fixation were always expressed at high levels, even during heterotrophic growth on glucose or fructose, which suggests a role for these pathways beyond the generation of reduced carbon units for cell growth, possibly in redox balancing of metabolism. Our results then indicate that S. novella, a representative of the Xanthobacteraceae family of methylotrophic soil and freshwater dwelling bacteria, employs a mixotrophic growth strategy under all conditions tested here. As a result the contribution of this bacterium to either carbon sequestration or the release of climate active substances could vary very quickly, which has direct implications for the modeling of such processes if mixotrophy proves to be the main growth strategy for large populations of soil bacteria.
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Affiliation(s)
- Ulrike Kappler
- School of Chemistry and Molecular Biosciences, The University of Queensland, St LuciaQLD, Australia
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Lu P, Jin L, Liang B, Zhang J, Li S, Feng Z, Huang X. Study of Biochemical Pathway and Enzyme Involved in Metsulfuron-Methyl Degradation by Ancylobacter sp. XJ-412-1 Isolated from Soil. Curr Microbiol 2011; 62:1718-25. [DOI: 10.1007/s00284-011-9919-z] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2011] [Accepted: 03/10/2011] [Indexed: 11/30/2022]
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Zaichikova MV, Berestovskaya YY, Akimov VN, Kizilova AK, Vasilieva LV. Ancylobacter abiegnus sp. nov., an oligotrophic member of the xylotrophic mycobacterial community. Microbiology (Reading) 2010. [DOI: 10.1134/s0026261710040107] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Lang E, Swiderski J, Stackebrandt E, Schumann P, Spröer C, Sahin N. Description of Ancylobacter oerskovii sp. nov. and two additional strains of Ancylobacter polymorphus. Int J Syst Evol Microbiol 2008; 58:1997-2002. [PMID: 18768594 DOI: 10.1099/ijs.0.65666-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A Gram-negative, pleomorphic, rod-shaped, non-spore-forming bacterium, designated strain NS05T, was isolated from soil after enrichment with oxalate. On the basis of 16S rRNA gene sequence similarity, strain NS05T was shown to be phylogenetically related to the genera Ancylobacter, Starkeya and Angulomicrobium (96.3-98.1% sequence similarity), class Alphaproteobacteria. Strain NS05T was most closely related to Ancylobacter rudongensis AS 1.1761T (98.1% sequence similarity). The whole-cell fatty acid pattern of strain NS05T was typical of those found in members of the genus Ancylobacter. Its main components were C(18:1)omega7c (60.4%), C(19:0)omega8c cyclo (28.3%) and C(16:0) (7.4%) and hydroxylated compounds were absent. The results of DNA-DNA hybridization and physiological and biochemical tests allowed genotypic and phenotypic differentiation of strain NS05T with respect to the four Ancylobacter species with validly published names. Therefore, it is concluded that NS05T represents a novel species of the genus Ancylobacter, for which the name Ancylobacter oerskovii sp. nov. is proposed. The type strain is NS05T (=DSM 18746T=CCM 7435T). Two other oxalate-utilizing strains, NS03 and NS04, isolated from paper-mill effluents, were shown by 16S rRNA gene sequence analysis to be affiliated to the species Ancylobacter polymorphus. The study of their physiological properties extends the knowledge of the physiological variability within this species.
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Affiliation(s)
- Elke Lang
- Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH, Inhoffenstrasse 7b, D-30124 Braunschweig, Germany.
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Trotsenko YA, Doronina NV, Li TD, Reshetnikov AS. Moderately haloalkaliphilic aerobic methylobacteria. Microbiology (Reading) 2007. [DOI: 10.1134/s0026261707030010] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Xin YH, Zhou YG, Chen WX. Ancylobacter polymorphus sp. nov. and Ancylobacter vacuolatus sp. nov. Int J Syst Evol Microbiol 2006; 56:1185-1188. [PMID: 16738088 DOI: 10.1099/ijs.0.64118-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The taxonomic positions of ‘Renobacter vacuolatum’ DSM 1277 and ‘Ancylobacter polymorphus’ DSM 2457 were investigated in this study. 16S rRNA gene sequence analysis indicated that both strains belonged to the genus Ancylobacter. DNA–DNA hybridization showed that they differed from Ancylobacter aquaticus DSM 101T and Ancylobacter rudongensis AS 1.1761T. According to molecular and phenotypic characteristics, strain DSM 1277T (=AS 1.2807T) is proposed as the type strain of Ancylobacter vacuolatus sp. nov. At the same time, valid publication of the name Ancylobacter polymorphus sp. nov. is proposed, with the type strain DSM 2457T (=AS 1.2800T=NCIMB 10516T).
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Affiliation(s)
- Yu Hua Xin
- China General Microbiological Culture Collection Center, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100080, People's Republic of China
- China Agricultural University, Beijing 100094, People's Republic of China
| | - Yu Guang Zhou
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100080, People's Republic of China
- China General Microbiological Culture Collection Center, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100080, People's Republic of China
| | - Wen Xin Chen
- China Agricultural University, Beijing 100094, People's Republic of China
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Lawrence JR, Chenier MR, Roy R, Beaumier D, Fortin N, Swerhone GDW, Neu TR, Greer CW. Microscale and molecular assessment of impacts of nickel, nutrients, and oxygen level on structure and function of river biofilm communities. Appl Environ Microbiol 2004; 70:4326-39. [PMID: 15240316 PMCID: PMC444833 DOI: 10.1128/aem.70.7.4326-4339.2004] [Citation(s) in RCA: 112] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Studies were carried out to assess the influence of nutrients, dissolved oxygen (DO) concentration, and nickel (Ni) on river biofilm development, structure, function, and community composition. Biofilms were cultivated in rotating annular reactors with river water at a DO concentration of 0.5 or 7.5 mg liter(-1), with or without a combination of carbon, nitrogen, and phosphorus (CNP) and with or without Ni at 0.5 mg liter(-1). The effects of Ni were apparent in the elimination of cyanobacterial populations and reduced photosynthetic biomass in the biofilm. Application of lectin-binding analyses indicated changes in exopolymer abundance and a shift in the glycoconjugate makeup of the biofilms, as well as in the response to all treatments. Application of the fluorescent live-dead staining (BacLight Live-Dead staining kit; Molecular Probes, Eugene, Oreg.) indicated an increase in the ratio of live to dead cells under low-oxygen conditions. Nickel treatments had 50 to 75% fewer 'live' cells than their corresponding controls. Nickel at 0.5 mg liter(-1) corresponding to the industrial release rate concentration for nickel resulted in reductions in carbon utilization spectra relative to control and CNP treatments without nickel. In these cases, the presence of nickel eliminated the positive influence of nutrients on the biofilm. Other culture-dependent analyses (plate counts and most probable number) revealed no significant treatment effect on the biofilm communities. In the presence of CNP and at both DO levels, Ni negatively affected denitrification but had no effect on hexadecane mineralization or sulfate reduction. Analysis of total community DNA indicated abundant eubacterial 16S ribosomal DNA (rDNA), whereas Archaea were not detected. Amplification of the alkB gene indicated a positive effect of CNP and a negative effect of Ni. The nirS gene was not detected in samples treated with Ni at 0.5 mg liter(-1), indicating a negative effect on specific populations of bacteria, such as denitrifiers, resulting in a reduction in diversity. Denaturing gradient gel electrophoresis revealed that CNP had a beneficial impact on biofilm bacterial diversity at high DO concentrations, but none at low DO concentrations, and that the negative effect of Ni on diversity was similar at both DO concentrations. Notably, Ni resulted in the appearance of unique bands in 16S rDNA from Ni, DO, and CNP treatments. Sequencing results confirmed that the bands belonged to bacteria originating from freshwater and marine environments or from agricultural soils and industrial effluents. The observations indicate that significant interactions occur between Ni, oxygen, and nutrients and that Ni at 0.5 mg liter(-1) may have significant impacts on river microbial community diversity and function.
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Affiliation(s)
- J R Lawrence
- National Water Research Institute, 11 Innovation Blvd., Saskatoon, Saskatchewan S7N 3H5, Canada.
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Lawrence J, Hendry M, Wassenaar L, Germida J, Wolfaardt G, Fortin N, Greer C. Distribution and Biogeochemical Importance of Bacterial Populations in a Thick Clay-Rich Aquitard System. MICROBIAL ECOLOGY 2000; 40:273-291. [PMID: 12035086 DOI: 10.1007/s002480000073] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2000] [Accepted: 07/21/2000] [Indexed: 05/23/2023]
Abstract
To investigate the distribution of microbial biomass, populations and activities within a clay-rich, low hydraulic conductivity (10-11 to 10-12 m s-1) aquitard complex, cores were aseptically obtained from a series of overlying clayey deposits; a fractured till, unfractured till (20-30 ka BP), a disturbed interfacial zone (20-30 ka BP), and a Cretaceous clay aquitard (71-72 Ma BP). The results of confocal microscopy studies, culture methods, molecular approaches, and extractive fatty acid analyses all indicated low bacterial numbers that were non-homogeneously distributed within the sediments. Various primers for catabolic genes were used to amplify extracted DNA. Results indicated the presence of eubacterial 23S rDNA, and the narH gene for nitrate reductase and ribulose-1,5-biphosphate carboxylase (RuBP carboxylase). Although there was no evidence of limitation by electron acceptors or donors, sulfate-reducing bacteria were not detected below the fractured till zone, using PCR, enrichment, or culture techniques. Denaturing gradient gel electrophoresis (DGGE) analyses indicated differences in community composition and abundance between the various geologic units. Results of FAME analyses of sediments yielded detectable extractable fatty acids throughout the aquitard complex. Bacterial activities were demonstrated by measuring mineralization of (14C) glucose. Porewater chemistry and stable isotope data were in keeping with an environment in which extremely slow growing, low populations of bacteria exert little impact. The observations also support the contention that in low permeability sediments bacteria may survive for geologic time periods.
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Affiliation(s)
- J.R. Lawrence
- National Water Research Institute, Environment Canada, Saskatoon, SK, Canada
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Liss SN, Bicho PA, Saddler JN. Microbiology and biodegradation of resin acids in pulp mill effluents: a minireview. Can J Microbiol 1997; 43:599-611. [PMID: 9246738 DOI: 10.1139/m97-086] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Resin acids, a group of diterpenoid carboxylic acids present mainly in softwood species, are present in many pulp mill effluents and toxic to fish in recipient waters. They are considered to be readily biodegradable. However, their removal across biological treatment systems has been shown to vary. Recent studies indicate that natural resin acids and transformation products may accumulate in sediments and pose acute and chronic toxicity to fish. Several resin acid biotransformation compounds have also been shown to bioaccumulate and to be more resistant to biodegradation than the original material. Until recently, the microbiology of resin-acid degradation has received only scant attention. Although wood-inhabiting fungi have been shown to decrease the level of resin present in wood, there is no conclusive evidence that fungi can completely degrade these compounds. In contrast, a number of bacterial isolates have recently been described which are able to utilize dehydroabietic or isopimaric acids as their sole carbon source. There appears to be an unusually high degree of substrate specificity with respect of the utilization of abietane congeners and the presence of substituents. Pimaranes do not appear to be attacked to the same extent as the abietanes. This paper reviews the occurrence, chemistry, toxicity, and biodegradation of resin acids in relation to the biological treatment of pulp and paper mill effluents.
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Affiliation(s)
- S N Liss
- Department of Applied Chemical and Biological Sciences, Ryerson Polytechnic University, Toronto, ON, Canada
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van den Wijngaard AJ, van der Kamp KW, van der Ploeg J, Pries F, Kazemier B, Janssen DB. Degradation of 1,2-dichloroethane by Ancylobacter aquaticus and other facultative methylotrophs. Appl Environ Microbiol 1992; 58:976-83. [PMID: 1575500 PMCID: PMC195365 DOI: 10.1128/aem.58.3.976-983.1992] [Citation(s) in RCA: 101] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Cultures of the newly isolated bacterial strains AD20, AD25, and AD27, identified as strains of Ancylobacter aquaticus, were capable of growth on 1,2-dichloroethane (DCE) as the sole carbon and energy source. These strains, as well as two other new DCE utilizers, were facultative methylotrophs and were also able to grow on 2-chloroethanol, chloroacetate, and 2-chloropropionate. In all strains tested, DCE was degraded by initial hydrolytic dehalogenation to 2-chloroethanol, followed by oxidation by a phenazine methosulfate-dependent alcohol dehydrogenase and an NAD-dependent aldehyde dehydrogenase. The resulting chloroacetic acid was converted to glycolate by chloroacetate dehalogenase. The alcohol dehydrogenase was induced during growth on methanol or DCE in strain AD20, but no activity was found during growth on glucose. However, in strain AD25 the enzyme was synthesized to a higher level during growth on glucose than on methanol, and it reached levels of around 2 U/mg of protein in late-exponential-phase cultures growing on glucose. The haloalkane dehalogenase was constitutively produced in all strains tested, but strain AD25 synthesized the enzyme at a level of 30 to 40% of the total cellular protein, which is much higher than that found in other DCE degraders. The nucleotide sequences of the haloalkane dehalogenase (dhlA) genes of strains AD20 and AD25 were the same as the sequence of dhlA from Xanthobacter autotrophicus GJ10 and GJ11. Hybridization experiments showed that the dhlA genes of six different DCE utilizers were all located on an 8.3-kb EcoRI restriction fragment, indicating that the organisms may have obtained the dhlA gene by horizontal gene transmission.
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Affiliation(s)
- A J van den Wijngaard
- Department of Biochemistry, Groningen Biotechnology Center, University of Groningen, The Netherlands
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Abstract
The bacteria having a unique ring-like morphology first isolated from nasal mucus by Weibel in 1887 were classified as a new genus Spirosoma by Migula in 1894. However, because these bacteria were not completely described for taxonomic purposes and their cultures were no longer available, the genus was deleted from the Bergey's Manual of Determinative Bacteriology, 6th edition, 1948. Orskov (1928) created a new genus "Microcyclus" (a name that has been found to be illegitimate and replaced with Ancylobacter by Raj 1983) to describe these nonmotile vibroid bacteria that occasionally formed ring-like structures. Several similar isolates found in many countries during the last 60 years were readily identified with this genus on the basis of the characteristic morphology alone. For the first time, these fascinating bacteria were extensively reviewed by Raj in 1977 and again in 1981. However, during the last decade, the systematics of these microcyclus bacteria has been reexamined and redefined. It has been shown that these Gram-negative ring-forming aerobic bacteria constitute a heterogeneous group of five genera: Ancylobacter, Cyclobacterium, Flectobacillus, Runella, and Spirosoma; the last four genera have been grouped into a family Spirosomaceace (reviving the old discarded name originally proposed by Migula 1894), thus separating them from the genus Ancylobacter which remains unaffiliated with any family yet (Bergey's Manual of Systematic Bacteriology, Vol. I, 9th ed., 1984). Also, this article reviews the recent studies reported on the ecology, morphogenesis, metabolism, and physiology of the picturesque bacteria.
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Affiliation(s)
- H D Raj
- Department of Microbiology, California State University, Long Beach
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