51
|
Surovy MZ, Rahman S, Rostás M, Islam T, von Tiedemann A. Suppressive Effects of Volatile Compounds from Bacillus spp. on Magnaporthe oryzae Triticum (MoT) Pathotype, Causal Agent of Wheat Blast. Microorganisms 2023; 11:1291. [PMID: 37317265 DOI: 10.3390/microorganisms11051291] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2023] [Revised: 05/02/2023] [Accepted: 05/04/2023] [Indexed: 06/16/2023] Open
Abstract
The Magnaporthe oryzae Triticum (MoT) pathotype is the causal agent of wheat blast, which has caused significant economic losses and threatens wheat production in South America, Asia, and Africa. Three bacterial strains from rice and wheat seeds (B. subtilis BTS-3, B. velezensis BTS-4, and B. velezensis BTLK6A) were used to explore the antifungal effects of volatile organic compounds (VOCs) of Bacillus spp. as a potential biocontrol mechanism against MoT. All bacterial treatments significantly inhibited both the mycelial growth and sporulation of MoT in vitro. We found that this inhibition was caused by Bacillus VOCs in a dose-dependent manner. In addition, biocontrol assays using detached wheat leaves infected with MoT showed reduced leaf lesions and sporulation compared to the untreated control. VOCs from B. velezensis BTS-4 alone or a consortium (mixture of B. subtilis BTS-3, B. velezensis BTS-4, and B. velezensis BTLK6A) of treatments consistently suppressed MoT in vitro and in vivo. Compared to the untreated control, VOCs from BTS-4 and the Bacillus consortium reduced MoT lesions in vivo by 85% and 81.25%, respectively. A total of thirty-nine VOCs (from nine different VOC groups) from four Bacillus treatments were identified by gas chromatography-mass spectrometry (GC-MS), of which 11 were produced in all Bacillus treatments. Alcohols, fatty acids, ketones, aldehydes, and S-containing compounds were detected in all four bacterial treatments. In vitro assays using pure VOCs revealed that hexanoic acid, 2-methylbutanoic acid, and phenylethyl alcohol are potential VOCs emitted by Bacillus spp. that are suppressive for MoT. The minimum inhibitory concentrations for MoT sporulation were 250 mM for phenylethyl alcohol and 500 mM for 2-methylbutanoic acid and hexanoic acid. Therefore, our results indicate that VOCs from Bacillus spp. are effective compounds to suppress the growth and sporulation of MoT. Understanding the MoT sporulation reduction mechanisms exerted by Bacillus VOCs may provide novel options to manage the further spread of wheat blast by spores.
Collapse
Affiliation(s)
- Musrat Zahan Surovy
- Division of Plant Pathology and Crop Protection, Department of Crop Sciences, Georg-August-University of Goettingen, Grisebachstrasse 6, 37077 Goettingen, Germany
- Institute of Biotechnology and Genetic Engineering (IBGE), Bangabandhu Sheikh Mujibur Rahman Agricultural University, Salna, Gazipur 1706, Bangladesh
| | - Shahinoor Rahman
- Division of Agricultural Entomology, Department of Crop Sciences, Georg-August-University of Goettingen, Grisebachstrasse 6, 37077 Goettingen, Germany
| | - Michael Rostás
- Division of Agricultural Entomology, Department of Crop Sciences, Georg-August-University of Goettingen, Grisebachstrasse 6, 37077 Goettingen, Germany
| | - Tofazzal Islam
- Institute of Biotechnology and Genetic Engineering (IBGE), Bangabandhu Sheikh Mujibur Rahman Agricultural University, Salna, Gazipur 1706, Bangladesh
| | - Andreas von Tiedemann
- Division of Plant Pathology and Crop Protection, Department of Crop Sciences, Georg-August-University of Goettingen, Grisebachstrasse 6, 37077 Goettingen, Germany
| |
Collapse
|
52
|
Liggins M, Ramírez Ramírez N, Abel-Santos E. Comparison of sporulation and germination conditions for Clostridium perfringens type A and G strains. Front Microbiol 2023; 14:1143399. [PMID: 37228374 PMCID: PMC10203408 DOI: 10.3389/fmicb.2023.1143399] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Accepted: 04/14/2023] [Indexed: 05/27/2023] Open
Abstract
Clostridium perfringens is a spore forming, anaerobic, Gram-positive bacterium that causes a range of diseases in humans and animals. C. perfringens forms spores, structures that are derived from the vegetative cell under conditions of nutrient deprivation and that allows survival under harsh environmental conditions. To return to vegetative growth, C. perfringens spores must germinate when conditions are favorable. Previous work in analyzing C. perfringens spore germination has produced strain-specific results. Hence, we analyzed the requirements for spore formation and germination in seven different C. perfringens strains. Our data showed that C. perfringens sporulation conditions are strain-specific, but germination responses are homogenous in all strains tested. C. perfringens spores can germinate using two distinct pathways. The first germination pathway (the amino acid-only pathway or AA) requires L-alanine, L-phenylalanine, and sodium ions (Na+) as co-germinants. L-arginine is not a required germinant but potentiates germination. The AA pathway is inhibited by aromatic amino acids and potassium ions (K+). Bicarbonate (HCO3-), on the other hand, bypasses potassium-mediated inhibition of C. perfringens spore germination through the AA pathway. The second germination pathway (the bile salt / amino acid pathway or BA) is more promiscuous and is activated by several bile salts and amino acids. In contrast to the AA pathway, the BA pathway is insensitive to Na+, although it can be activated by either K+ or HCO3-. We hypothesize that some C. perfringens strains may have evolved these two distinct germination pathways to ensure spore response to different host environments.
Collapse
Affiliation(s)
- Marc Liggins
- Department of Chemistry and Biochemistry, University of Nevada, Las Vegas, Las Vegas, NV, United States
| | - Norma Ramírez Ramírez
- Department of Chemistry and Biochemistry, University of Nevada, Las Vegas, Las Vegas, NV, United States
- Departamento de Biología, Universidad de Guanajuato, Guanajuato, Mexico
| | - Ernesto Abel-Santos
- Department of Chemistry and Biochemistry, University of Nevada, Las Vegas, Las Vegas, NV, United States
| |
Collapse
|
53
|
Park ZM, Belnap E, Remillard M, Rose MD. Vir1p, the yeast homolog of virilizer, is required for mRNA m6A methylation and meiosis. Genetics 2023; 224:iyad043. [PMID: 36930734 PMCID: PMC10474941 DOI: 10.1093/genetics/iyad043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 03/09/2023] [Accepted: 03/09/2023] [Indexed: 03/19/2023] Open
Abstract
N6-Methyladenosine (m6A) is among the most abundant modifications of eukaryotic mRNAs. mRNA methylation regulates many biological processes including playing an essential role in meiosis. During meiosis in the budding yeast, Saccharomyces cerevisiae, m6A levels peak early, before the initiation of the meiotic divisions. High-throughput studies suggested, and this work confirms that the uncharacterized protein Ygl036wp interacts with Kar4p, a component of the mRNA m6A-methyltransferase complex. Protein structure programs predict that Ygl036wp folds like VIRMA/Virilizer/VIR, which is involved in mRNA m6A-methylation in higher eukaryotes. In addition, Ygl036wp contains conserved motifs shared with VIRMA/Virilizer/VIR. Accordingly, we propose the name VIR1 for budding yeast ortholog of VIRMA/Virilizer/VIR 1. Vir1p interacts with all other members of the yeast methyltransferase complex and is itself required for mRNA m6A methylation and meiosis. In the absence of Vir1p proteins comprising the methyltransferase complex become unstable, suggesting that Vir1p acts as a scaffold for the complex. The vir1Δ/Δ mutant is defective for the premeiotic S-phase, which is suppressed by overexpression of the early meiotic transcription factor IME1; additional overexpression of the translational regulator RIM4 is required for sporulation. The vir1Δ/Δ mutant exhibits reduced levels of IME1 mRNA, as well as transcripts within Ime1p's regulon. Suppression by IME1 revealed an additional defect in the expression of the middle meiotic transcription factor, Ndt80p (and genes in its regulon), which is rescued by overexpression of RIM4. Together, these data suggest that Vir1p is required for cells to initiate the meiotic program and for progression through the meiotic divisions and spore formation.
Collapse
Affiliation(s)
- Zachory M Park
- Department of Biology, Georgetown University, Washington, DC 20057, USA
| | - Ethan Belnap
- Department of Biology, Georgetown University, Washington, DC 20057, USA
| | - Matthew Remillard
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Mark D Rose
- Department of Biology, Georgetown University, Washington, DC 20057, USA
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| |
Collapse
|
54
|
Chandra H, Sorg JA, Hassett DJ, Sun X. Regulatory transcription factors of Clostridioides difficile pathogenesis with a focus on toxin regulation. Crit Rev Microbiol 2023; 49:334-349. [PMID: 35389761 DOI: 10.1080/1040841x.2022.2054307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 02/26/2022] [Accepted: 03/14/2022] [Indexed: 11/03/2022]
Abstract
Clostridioides difficile (CD), a nosocomial gut pathogen, produces two major exotoxins, TcdA and TcdB, which disrupt the gut epithelial barrier and induce inflammatory/immune responses, leading to symptoms ranging from mild diarrhoea to pseudomembranous colitis and potentially to death. The expression of toxins is regulated by various transcription factors (TFs) which are induced in response to CD physiological life stages, nutritional availability, and host environment. This review summarises our current understanding on the regulation of toxin expression by TFs that interconnect with pathways of flagellar synthesis, quorum sensing, motility, biofilm formation, sporulation, and phase variation. The pleiotropic roles of some key TFs suggest that toxin production is tightly linked to other cellular processes of the CD physiology.
Collapse
Affiliation(s)
- Harish Chandra
- Department of Environmental Microbiology, School of Environmental and Earth Sciences, Babasaheb Bhimrao Ambedkar University, Lucknow, India
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Joseph A Sorg
- Department of Biology, Texas A&M University, College Station, TX, USA
| | - Daniel J Hassett
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Xingmin Sun
- Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL, USA
| |
Collapse
|
55
|
Chen S, Li F, Liu G, Li Y, Li Z, Liu Y, Nakanishi H. Construction of a Yeast Cell-Based Assay System to Analyze SNAP25-Targeting Botulinum Neurotoxins. Microorganisms 2023; 11:1125. [PMID: 37317099 DOI: 10.3390/microorganisms11051125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 04/15/2023] [Accepted: 04/21/2023] [Indexed: 06/16/2023] Open
Abstract
Herein, we describe a yeast cell-based assay system to analyze SNAP25-targeting botulinum neurotoxins (BoNTs). BoNTs are protein toxins, and, upon incorporation into neuronal cells, their light chains (BoNT-LCs) target specific synaptosomal N-ethylmaleimide-sensitive attachment protein receptor (SNARE) proteins, including synaptosomal-associated protein 25 (SNAP25). BoNT-LCs are metalloproteases, and each BoNT-LC recognizes and cleaves conserved domains in SNAREs termed the SNARE domain. In the budding yeast Saccharomyces cerevisiae, the SNAP25 ortholog Spo20 is required for production of the spore plasma membrane; thus, defects in Spo20 cause sporulation deficiencies. We found that chimeric SNAREs in which SNARE domains in Spo20 are replaced with those of SNAP25 are functional in yeast cells. The Spo20/SNAP25 chimeras, but not Spo20, are sensitive to digestion by BoNT-LCs. We demonstrate that spo20∆ yeasts harboring the chimeras exhibit sporulation defects when various SNAP25-targeting BoNT-LCs are expressed. Thus, the activities of BoNT-LCs can be assessed by colorimetric measurement of sporulation efficiencies. Although BoNTs are notorious toxins, they are also used as therapeutic and cosmetic agents. Our assay system will be useful for analyzing novel BoNTs and BoNT-like genes, as well as their manipulation.
Collapse
Affiliation(s)
- Shilin Chen
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214126, China
| | - Feng Li
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214126, China
| | - Guoyu Liu
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214126, China
| | - Yuqing Li
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214126, China
| | - Zijie Li
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214126, China
| | - Yishi Liu
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214126, China
| | - Hideki Nakanishi
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214126, China
| |
Collapse
|
56
|
Collins KM, Evans NJ, Torpey JH, Harris JM, Haynes BA, Camp AH, Isaacson RL. Structural Analysis of Bacillus subtilis Sigma Factors. Microorganisms 2023; 11:microorganisms11041077. [PMID: 37110501 PMCID: PMC10141391 DOI: 10.3390/microorganisms11041077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Revised: 04/16/2023] [Accepted: 04/17/2023] [Indexed: 04/29/2023] Open
Abstract
Bacteria use an array of sigma factors to regulate gene expression during different stages of their life cycles. Full-length, atomic-level structures of sigma factors have been challenging to obtain experimentally as a result of their many regions of intrinsic disorder. AlphaFold has now supplied plausible full-length models for most sigma factors. Here we discuss the current understanding of the structures and functions of sigma factors in the model organism, Bacillus subtilis, and present an X-ray crystal structure of a region of B. subtilis SigE, a sigma factor that plays a critical role in the developmental process of spore formation.
Collapse
Affiliation(s)
- Katherine M Collins
- Department of Chemistry, King's College London, Britannia House, 7 Trinity Street, London SE1 1DB, UK
| | - Nicola J Evans
- Department of Chemistry, King's College London, Britannia House, 7 Trinity Street, London SE1 1DB, UK
| | - James H Torpey
- Department of Chemistry, King's College London, Britannia House, 7 Trinity Street, London SE1 1DB, UK
| | - Jonathon M Harris
- Department of Chemistry, King's College London, Britannia House, 7 Trinity Street, London SE1 1DB, UK
| | - Bethany A Haynes
- Department of Chemistry, King's College London, Britannia House, 7 Trinity Street, London SE1 1DB, UK
| | - Amy H Camp
- Department of Biological Sciences, Mount Holyoke College, 50 College Street, South Hadley, MA 01075, USA
| | - Rivka L Isaacson
- Department of Chemistry, King's College London, Britannia House, 7 Trinity Street, London SE1 1DB, UK
| |
Collapse
|
57
|
Wei C, Wen C, Zhang Y, Du H, Zhong R, Guan Z, Wang M, Qin Y, Wang F, Song L, Zhao Y. The FomYjeF Protein Influences the Sporulation and Virulence of Fusarium oxysporum f. sp. momordicae. Int J Mol Sci 2023; 24:ijms24087260. [PMID: 37108422 PMCID: PMC10138616 DOI: 10.3390/ijms24087260] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 04/06/2023] [Accepted: 04/13/2023] [Indexed: 04/29/2023] Open
Abstract
Fusarium oxysporum causes vascular wilt in more than 100 plant species, resulting in massive economic losses. A deep understanding of the mechanisms of pathogenicity and symptom induction by this fungus is necessary to control crop wilt. The YjeF protein has been proven to function in cellular metabolism damage-repair in Escherichia coli and to play an important role in Edc3 (enhancer of the mRNA decapping 3) function in Candida albicans, but no studies have been reported on related functions in plant pathogenic fungi. In this work, we report how the FomYjeF gene in F. oxysporum f. sp. momordicae contributes to conidia production and virulence. The deletion of the FomYjeF gene displayed a highly improved capacity for macroconidia production, and it was shown to be involved in carbendazim's associated stress pathway. Meanwhile, this gene caused a significant increase in virulence in bitter gourd plants with a higher disease severity index and enhanced the accumulation of glutathione peroxidase and the ability to degrade hydrogen peroxide in F. oxysporum. These findings reveal that FomYjeF affects virulence by influencing the amount of spore formation and the ROS (reactive oxygen species) pathway of F. oxysporum f. sp. momordicae. Taken together, our study shows that the FomYjeF gene affects sporulation, mycelial growth, pathogenicity, and ROS accumulation in F. oxysporum. The results of this study provide a novel insight into the function of FomYjeF participation in the pathogenicity of F. oxysporum f. sp. momordicae.
Collapse
Affiliation(s)
- Chenxing Wei
- College of Plant Protection, Henan Agricultural University, Zhengzhou 450046, China
| | - Caiyi Wen
- College of Plant Protection, Henan Agricultural University, Zhengzhou 450046, China
| | - Yuanyuan Zhang
- College of Plant Protection, Henan Agricultural University, Zhengzhou 450046, China
| | - Hongyan Du
- College of Plant Protection, Henan Agricultural University, Zhengzhou 450046, China
| | - Rongrong Zhong
- College of Plant Protection, Henan Agricultural University, Zhengzhou 450046, China
| | - Zhengzhe Guan
- College of Plant Protection, Henan Agricultural University, Zhengzhou 450046, China
| | - Mengjiao Wang
- College of Plant Protection, Henan Agricultural University, Zhengzhou 450046, China
| | - Yanhong Qin
- Institute of Plant Protection, Henan Academy of Agricultural Sciences, Zhengzhou 450002, China
| | - Fei Wang
- Institute of Plant Protection, Henan Academy of Agricultural Sciences, Zhengzhou 450002, China
| | - Luyang Song
- College of Plant Protection, Henan Agricultural University, Zhengzhou 450046, China
| | - Ying Zhao
- College of Plant Protection, Henan Agricultural University, Zhengzhou 450046, China
| |
Collapse
|
58
|
Schwartz DA, Rodríguez-Ramos JA, Shaffer M, Flynn RM, Daly RA, Wrighton KC, Lennon JT. Human-Gut Phages Harbor Sporulation Genes. mBio 2023:e0018223. [PMID: 37042671 DOI: 10.1128/mbio.00182-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/13/2023] Open
Abstract
Spore-forming bacteria are prevalent in mammalian guts and have implications for host health and nutrition. The production of dormant spores is thought to play an important role in the colonization, persistence, and transmission of these bacteria. Spore formation also modifies interactions among microorganisms such as infection by phages. Recent studies suggest that phages may counter dormancy-mediated defense through the expression of phage-carried sporulation genes during infection, which can alter the transitions between active and inactive states. By mining genomes and gut-derived metagenomes, we identified sporulation genes that are preferentially carried by phages that infect spore-forming bacteria. These included genes involved in chromosome partitioning, DNA damage repair, and cell wall-associated functions. In addition, phages contained homologs of sporulation-specific transcription factors, notably spo0A, the master regulator of sporulation, which could allow phages to control the complex genetic network responsible for spore development. Our findings suggest that phages could influence the formation of bacterial spores with implications for the health of the human gut microbiome, as well as bacterial communities in other environments. IMPORTANCE Phages acquire bacterial genes and use them to alter host metabolism in ways that enhance phage fitness. To date, most auxiliary genes replace or modulate enzymes that are used by the host for nutrition or energy production. However, phage fitness is affected by all aspects of host physiology, including decisions that reduce the metabolic activity of the cell. Here, we focus on endosporulation, a complex and ancient form of dormancy found among the Bacillota that involves hundreds of genes. By coupling homology searches with host classification, we identified 31 phage-carried homologs of sporulation genes that are mostly limited to phages infecting spore-forming bacteria. Nearly one-third of the homologs recovered were regulatory genes, suggesting that phages may manipulate host genetic networks by tapping into their control elements. Our findings also suggest a mechanism by which phages can overcome the defensive strategy of dormancy, which may be involved in coevolutionary dynamics of spore-forming bacteria.
Collapse
Affiliation(s)
- Daniel A Schwartz
- Department of Biology, Indiana University, Bloomington, Indiana, USA
| | - Josué A Rodríguez-Ramos
- Department of Soil and Crop Sciences, Colorado State University, Fort Collins, Colorado, USA
| | - Michael Shaffer
- Department of Soil and Crop Sciences, Colorado State University, Fort Collins, Colorado, USA
| | - Rory M Flynn
- Department of Soil and Crop Sciences, Colorado State University, Fort Collins, Colorado, USA
| | - Rebecca A Daly
- Department of Soil and Crop Sciences, Colorado State University, Fort Collins, Colorado, USA
| | - Kelly C Wrighton
- Department of Soil and Crop Sciences, Colorado State University, Fort Collins, Colorado, USA
| | - Jay T Lennon
- Department of Biology, Indiana University, Bloomington, Indiana, USA
| |
Collapse
|
59
|
Krzepiłko A, Matyszczuk KM, Święciło A. Effect of Sublethal Concentrations of Zinc Oxide Nanoparticles on Bacillus cereus. Pathogens 2023; 12:pathogens12030485. [PMID: 36986407 PMCID: PMC10053889 DOI: 10.3390/pathogens12030485] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Revised: 03/10/2023] [Accepted: 03/17/2023] [Indexed: 03/30/2023] Open
Abstract
Zinc oxide nanoparticles (ZnONPs), which are produced on a large scale, pose a potential threat to various environments because they can interact with the microbial populations found in them. Bacteria that are widespread in soil, water, and plant material include the Bacillus cereus group, which plays an important role in biodegradation and the nutrient cycle and is a major factor determining ecological balance. This group includes, among others, the foodborne pathogen B. cereus sensu stricto (herein referred to as B. cereus). The aim of this study was a comprehensive assessment of the effects of commercially available ZnONPs on B. cereus. The MIC (minimum inhibitory concentration) for B. cereus was 1.6 mg/mL, and the MBC (minimum bactericidal concentration) was 1.8 mg/mL. Growth of B. cereus was inhibited by a concentration of ZnONPs lower than or equal to MIC50. Concentrations from 0.2 to 0.8 mg/mL inhibited the growth of these bacteria in liquid media, induced symptoms of oxidative stress, and stimulated an environmental stress response in the form of biofilm and endospore formation. In addition, ZnONPs negatively affected the ability of the bacteria to break down the azo dye Evans Blue but enhanced the antimicrobial properties of phenolic compounds. Sublethal concentrations of ZnONPs generally decreased the activity of B. cereus cells, especially in the presence of phenolics, which indicates their potential toxicological impact, but at the same time they induced universal defence responses in these cells, which in the case of potential pathogens can hinder their removal.
Collapse
Affiliation(s)
- Anna Krzepiłko
- Department of Biotechnology, Microbiology and Human Nutrition, University of Life Sciences in Lublin, 20-950 Lublin, Poland
| | - Katarzyna Magdalena Matyszczuk
- Department of Biotechnology, Microbiology and Human Nutrition, University of Life Sciences in Lublin, 20-950 Lublin, Poland
| | - Agata Święciło
- Department of Environmental Microbiology, Faculty of Agrobioengineering, University of Life Sciences in Lublin, 20-069 Lublin, Poland
| |
Collapse
|
60
|
Pérez-Lorente AI, Molina-Santiago C, de Vicente A, Romero D. Sporulation Activated via σ W Protects Bacillus from a Tse1 Peptidoglycan Hydrolase Type VI Secretion System Effector. Microbiol Spectr 2023; 11:e0504522. [PMID: 36916921 PMCID: PMC10100999 DOI: 10.1128/spectrum.05045-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Accepted: 02/21/2023] [Indexed: 03/16/2023] Open
Abstract
Within bacterial communities, community members engage in interactions employing diverse offensive and defensive tools to reach coexistence. Extracellular-matrix production and sporulation are defensive mechanisms used by Bacillus subtilis cells when they interact with Pseudomonas chlororaphis strains expressing a type VI secretion system (T6SS). Here, we define Tse1 as the main toxin mobilized by the Pseudomonas chlororaphis T6SS that triggers sporulation in Bacillus subtilis. We characterize Tse1 as a peptidoglycan hydrolase that indirectly alters the dynamics and functionality of the Bacillus cell membrane. We also delineate the response of Bacillus cells to Tse1, which through the coordinated actions of the extracellular sigma factor σW and the cytoplasmic histidine kinases KinA and KinB, culminates in activation of the sporulation cascade. We propose that this cellular developmental response permits bacilli to defend against the toxicity of T6SS-mobilized Tse1 effector. IMPORTANCE The study of bacterial interactions is helping to define species-specific strategies used to modulate the competition dynamics underlying the development of community compositions. In this study, we deciphered the role of Pseudomonas T6SS when competing with Bacillus and the mechanism by which a T6SS-toxin modifies Bacillus physiology. We found that Pseudomonas triggers Bacillus sporulation by injecting through T6SS a toxin that we called Tse1. We found that Tse1 is a hydrolase that degrades Bacillus peptidoglycan and indirectly damages Bacillus membrane functionality. In addition, we demonstrated the mechanism by which Bacillus cells increase the sporulation rate upon recognition of the presence of Tse1. Interestingly, asporogenic Bacillus cells are more sensitive to T6SS activity, which led us to propose sporulation as a last resort of bacilli to overcome this family of toxins.
Collapse
Affiliation(s)
- Alicia I. Pérez-Lorente
- Instituto de Hortofruticultura Subtropical y Mediterránea La Mayora, Universidad de Málaga-Consejo Superior de Investigaciones Científicas, Departamento de Microbiología, Universidad de Málaga, Málaga, Spain
| | - Carlos Molina-Santiago
- Instituto de Hortofruticultura Subtropical y Mediterránea La Mayora, Universidad de Málaga-Consejo Superior de Investigaciones Científicas, Departamento de Microbiología, Universidad de Málaga, Málaga, Spain
| | - Antonio de Vicente
- Instituto de Hortofruticultura Subtropical y Mediterránea La Mayora, Universidad de Málaga-Consejo Superior de Investigaciones Científicas, Departamento de Microbiología, Universidad de Málaga, Málaga, Spain
| | - Diego Romero
- Instituto de Hortofruticultura Subtropical y Mediterránea La Mayora, Universidad de Málaga-Consejo Superior de Investigaciones Científicas, Departamento de Microbiología, Universidad de Málaga, Málaga, Spain
| |
Collapse
|
61
|
Feaga HA, Hong HR, Prince CR, Rankin A, Buskirk AR, Dworkin J. Elongation Factor P Is Important for Sporulation Initiation. J Bacteriol 2023; 205:e0037022. [PMID: 36651772 DOI: 10.1128/jb.00370-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
The universally conserved protein elongation factor P (EF-P) facilitates translation at amino acids that form peptide bonds with low efficiency, particularly polyproline tracts. Despite its wide conservation, it is not essential in most bacteria and its physiological role remains unclear. Here, we show that EF-P affects the process of sporulation initiation in the bacterium Bacillus subtilis. We observe that the lack of EF-P delays expression of sporulation-specific genes. Using ribosome profiling, we observe that expression of spo0A, encoding a transcription factor that functions as the master regulator of sporulation, is lower in a Δefp strain than the wild type. Ectopic expression of Spo0A rescues the sporulation initiation phenotype, indicating that reduced spo0A expression explains the sporulation defect in Δefp cells. Since Spo0A is the earliest sporulation transcription factor, these data suggest that sporulation initiation can be delayed when protein synthesis is impaired. IMPORTANCE Elongation factor P (EF-P) is a universally conserved translation factor that prevents ribosome stalling at amino acids that form peptide bonds with low efficiency, particularly polyproline tracts. Phenotypes associated with EF-P deletion are pleiotropic, and the mechanistic basis underlying many of these phenotypes is unclear. Here, we show that the absence of EF-P affects the ability of B. subtilis to initiate sporulation by preventing normal expression of Spo0A, the key transcriptional regulator of this process. These data illustrate a mechanism that accounts for the sporulation delay and further suggest that cells are capable of sensing translation stress before committing to sporulation.
Collapse
|
62
|
Gupte AP, Pierantoni DC, Conti A, Donati L, Basaglia M, Casella S, Favaro L, Corte L, Cardinali G. Renewing Lost Genetic Variability with a Classical Yeast Genetics Approach. J Fungi (Basel) 2023; 9:jof9020264. [PMID: 36836378 PMCID: PMC9958831 DOI: 10.3390/jof9020264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 02/06/2023] [Accepted: 02/13/2023] [Indexed: 02/18/2023] Open
Abstract
Due to their long domestication time course, many industrial Saccharomyces cerevisiae strains are adopted in numerous processes mostly for historical reasons instead of scientific and technological needs. As such, there is still significant room for improvement for industrial yeast strains relying on yeast biodiversity. This paper strives to regenerate biodiversity with the innovative application of classic genetic methods to already available yeast strains. Extensive sporulation was indeed applied to three different yeast strains, specifically selected for their different origins as well as backgrounds, with the aim of clarifying how new variability was generated. A novel and easy method to obtain mono-spore colonies was specifically developed, and, to reveal the extent of the generated variability, no selection after sporulation was introduced. The obtained progenies were then tested for their growth in defined mediums with high stressor levels. A considerable and strain-specific increase in both phenotypic and metabolomic variability was assessed, and a few mono-spore colonies were found to be of great interest for their future exploitation in selected industrial processes.
Collapse
Affiliation(s)
- Ameya Pankaj Gupte
- Department of Agronomy Food natural Resources Animals and Environment (DAFNAE), University of Padova, 35020 Legnaro, Italy
| | | | - Angela Conti
- Department of Pharmaceutical Sciences, University of Perugia, 06121 Perugia, Italy
| | - Leonardo Donati
- Department of Pharmaceutical Sciences, University of Perugia, 06121 Perugia, Italy
| | - Marina Basaglia
- Department of Agronomy Food natural Resources Animals and Environment (DAFNAE), University of Padova, 35020 Legnaro, Italy
| | - Sergio Casella
- Department of Agronomy Food natural Resources Animals and Environment (DAFNAE), University of Padova, 35020 Legnaro, Italy
| | - Lorenzo Favaro
- Department of Agronomy Food natural Resources Animals and Environment (DAFNAE), University of Padova, 35020 Legnaro, Italy
- Correspondence: (L.F.); (L.C.)
| | - Laura Corte
- Department of Pharmaceutical Sciences, University of Perugia, 06121 Perugia, Italy
- Correspondence: (L.F.); (L.C.)
| | - Gianluigi Cardinali
- Department of Pharmaceutical Sciences, University of Perugia, 06121 Perugia, Italy
| |
Collapse
|
63
|
Karuppiah V, Zhang C, Liu T, Li Y, Chen J. Transcriptome Analysis of T. asperellum GDFS 1009 Revealed the Role of MUP1 Gene on the Methionine-Based Induction of Morphogenesis and Biological Control Activity. J Fungi (Basel) 2023; 9:jof9020215. [PMID: 36836329 PMCID: PMC9963050 DOI: 10.3390/jof9020215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 01/25/2023] [Accepted: 01/31/2023] [Indexed: 02/10/2023] Open
Abstract
Trichoderma spp. are biological control agents extensively used against various plant pathogens. However, the key genes shared for the growth, development and biological activity are unclear. In this study, we explored the genes responsible for the growth and development of T. asperellum GDFS 1009 under liquid-shaking culture compared to solid-surface culture. Transcriptome analysis revealed 2744 differentially expressed genes, and RT-qPCR validation showed that the high-affinity methionine permease MUP1 was the key gene for growth under different media. Deletion of the MUP1 inhibited the transport of amino acids, especially methionine, thereby inhibiting mycelial growth and sporulation, whereas inhibition could be mitigated by adding methionine metabolites such as SAM, spermidine and spermine. The MUP1 gene responsible for the methionine-dependent growth of T. asperellum was confirmed to be promoted through the PKA pathway but not the MAPK pathway. Furthermore, the MUP1 gene also increased the mycoparasitic activity of T. asperellum against Fusarium graminearum. Greenhouse experiments revealed that MUP1 strengthens the Trichoderma-induced crop growth promotion effect and SA-induced pathogen defense potential in maize. Our study highlights the effect of the MUP1 gene on growth and morphological differentiation and its importance for the agricultural application of Trichoderma against plant diseases.
Collapse
Affiliation(s)
- Valliappan Karuppiah
- School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China
- State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Cheng Zhang
- School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China
- State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Tong Liu
- Key Laboratory of Genetics and Germplasm Innovation of Tropical Special Forest Trees and Ornamental Plants, Ministry of Education, Hainan University, Haikou 570228, China
| | - Yi Li
- Shanghai Dajing Biotec. Ltd., Shanghai 201100, China
| | - Jie Chen
- School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China
- State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai 200240, China
- Correspondence:
| |
Collapse
|
64
|
Mukherjee S, Bhakta K, Ghosh A, Ghosh A. Ger1 is a secreted aspartic acid protease essential for spore germination in Ustilago maydis. Yeast 2023; 40:102-116. [PMID: 36562128 DOI: 10.1002/yea.3835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2022] [Revised: 12/19/2022] [Accepted: 12/21/2022] [Indexed: 12/24/2022] Open
Abstract
Ustilago maydis expresses a number of proteases during its pathogenic lifecycle. Some of the proteases including both intracellular and extracellular ones have previously been shown to influence the virulence of the pathogen. However, any role of secreted proteases in the sporulation process of U. maydis have not been explored earlier. In this study we have investigated the biological function of one such secreted protease, Ger1 belonging to aspartic protease A1 family. An assessment of the real time expression of ger1 revealed an infection specific expression of the protein especially during late phases of infection. We also evaluated any contribution of the protein in the pathogenicity of the fungus. Our data revealed an involvement of Ger1 in the sporulation and spore germination processes of U. maydis. Ger1 also showed positive influence on the pathogenicity of the fungus and accordingly the ger1 deletion mutant exhibited reduced pathogenicity. The study also demonstrated the protease activity associated with Ger1 to be essential for its biological function. Fluorescence microscopy of maize plants infected with U. maydis cells expressing Ger1-mcherry-HA also revealed that Ger1 is efficiently secreted within maize apoplast.
Collapse
Affiliation(s)
| | - Koustav Bhakta
- Department of Biochemistry, Bose Institute, Kolkata, India
| | | | - Anupama Ghosh
- Division of Plant Biology, Bose Institute, Kolkata, India
| |
Collapse
|
65
|
Kong M, D'Atri D, Bilotta MT, Johnson B, Updegrove TB, Gallardo DL, Machinandiarena F, Wu IL, Constantino MA, Hewitt SM, Tanner K, Fitzgerald DJ, Ramamurthi KS. Cell-specific cargo delivery using synthetic bacterial spores. Cell Rep 2023; 42:111955. [PMID: 36640333 PMCID: PMC10009695 DOI: 10.1016/j.celrep.2022.111955] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Revised: 11/21/2022] [Accepted: 12/15/2022] [Indexed: 01/06/2023] Open
Abstract
Delivery of cancer therapeutics to non-specific sites decreases treatment efficacy while increasing toxicity. In ovarian cancer, overexpression of the cell surface marker HER2, which several therapeutics target, relates to poor prognosis. We recently reported the assembly of biocompatible bacterial spore-like particles, termed "SSHELs." Here, we modify SSHELs with an affibody directed against HER2 and load them with the chemotherapeutic agent doxorubicin. Drug-loaded SSHELs reduce tumor growth and increase survival with lower toxicity in a mouse tumor xenograft model compared with free drug and with liposomal doxorubicin by preferentially accumulating in the tumor mass. Target cells actively internalize and then traffic bound SSHELs to acidic compartments, whereupon the cargo is released to the cytosol in a pH-dependent manner. We propose that SSHELs represent a versatile strategy for targeted drug delivery, especially in cancer settings.
Collapse
Affiliation(s)
- Minsuk Kong
- Laboratory of Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA; Department of Food Science and Technology, Seoul National University of Science and Technology, Seoul 01811, South Korea
| | - Domenico D'Atri
- Laboratory of Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Maria Teresa Bilotta
- Laboratory of Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Bailey Johnson
- Laboratory of Cell Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Taylor B Updegrove
- Laboratory of Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Devorah L Gallardo
- Laboratory Animal Sciences Program, Leidos Biomedical Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Federico Machinandiarena
- Laboratory of Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - I-Lin Wu
- Laboratory of Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Maira Alves Constantino
- Laboratory of Cell Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Stephen M Hewitt
- Laboratory of Pathology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Kandice Tanner
- Laboratory of Cell Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
| | - David J Fitzgerald
- Laboratory of Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Kumaran S Ramamurthi
- Laboratory of Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
| |
Collapse
|
66
|
Murshed M, Al-Quraishy S, Alghamdi J, Aljawdah HMA, Mares MM. The Anticoccidial Effect of Alcoholic Vitis vinifera Leaf Extracts on Eimeria papillate Oocysts Isolated in Mice In Vitro and In Vivo. Vet Sci 2023; 10:vetsci10020097. [PMID: 36851401 PMCID: PMC9966314 DOI: 10.3390/vetsci10020097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 01/21/2023] [Accepted: 01/26/2023] [Indexed: 01/31/2023] Open
Abstract
Eimeria spp. causes eimeriosis in the guts of numerous domestic mammals and poultry, and the employment of medication and the effects of certain aspects of synthetic anticoccidials in the treatment of eimeriosis have given rise to the appearance of resistant parasites that require the search for alternate remedies. Natural products, which are safe and have no negative impact on the environment, may be utilized in the therapy of an enormous range of parasitic infections. This research aimed to assess the effectiveness of VVLE on the oocyst sporulation of an E. papillate infection in the mouse jejunum. In addition, obtaining the ideal concentration will interrupt the parasite's life cycle and limit infection. In vitro: Collected unsporulated oocysts (1 × 103) of E. papillata were given six different concentrations (w/v) of Vitis vinifera leaf extract (10, 25, 50, 100, 150, and 200 mg/mL) and toltrazuril (25 mg/mL), three replicates per group, whereas the control group received 2.5% potassium dichromate solution. In vivo: The mice were separated into six groups; the first and second groups did not receive infection, whilst the third, fourth, fifth, and sixth groups were each given 1 × 103 sporulated oocysts of E. papillate in the experiment. In addition, an oral dosage of 100 and 200 mg/kg VVLE were given to the fourth and fifth groups, while the sixth group was given toltrazuril at 25 mg/kg. On the fifth day, unpopulated oocysts were collected from each mouse separately. The incubation period and treatments had considerable impacts on the rate of sporulation. The infrared spectroscopy of V. vinifera extract revealed many expected active classes of chemical compounds. Further, the infection of mice with E. papillata caused an oocyst output of nearly 2 × 104 oocysts/g of faeces. VVLE significantly decreased the oocyst output to nearly 88%. In addition, we detected an inhibitory effect on the sporulation (%) and harm (%) of E. papillata oocysts in a dosage-dependent modality compared with the control group. Furthermore, they destroyed the oocyst morphology in terms of the shape, size, and quantity of sporocysts. The results indicate that grape vines have powerful activity as anticoccidials.
Collapse
|
67
|
Kong P, Daughtrey ML, Hong C. Differential Adaptation Has Resulted in Aggressiveness Variation of Calonectria pseudonaviculata on Hosts Buxus, Pachysandra, and Sarcococca. J Fungi (Basel) 2023; 9:jof9020181. [PMID: 36836296 PMCID: PMC9966688 DOI: 10.3390/jof9020181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Revised: 01/23/2023] [Accepted: 01/26/2023] [Indexed: 01/31/2023] Open
Abstract
Calonectria pseudonaviculata (Cps) infects Buxus (boxwood), Pachysandra (pachysandra), and Sarcococca spp. (sweet box); yet, how it adapts to its hosts has been unclear. Here, we performed serial passage experiments with the three hosts and measured Cps changes in three aggressiveness components: infectibility, lesion size, and conidial production. The detached leaves of individual hosts were inoculated with isolates (P0) from the originating host, followed by nine serial inoculations of new leaves of the same host with conidia from the infected leaves of the previous inoculation. All boxwood isolates maintained their capability of infection and lesion expansion through the 10 passages, whereas most non-boxwood isolates lost these abilities during the passages. Isolates from plants of origin (*-P0) and their descendants isolated from passages 5 (*-P5) and 10 (*-P10) were used to evaluate aggressiveness changes on all three hosts with cross-inoculation. While post-passage boxwood isolates gave enlarged lesions on pachysandra, sweet box P5 and pachysandra P10 isolates showed reduced aggressiveness on all hosts. Cps appears to be most adapted to boxwood and less adapted to sweet box and pachysandra. These results suggest speciation of Cps, with its coevolutionary pace with the hosts the fastest with boxwood, intermediate with sweet box, and the slowest with pachysandra.
Collapse
Affiliation(s)
- Ping Kong
- Hampton Roads Agricultural Research and Extension Center, Virginia Tech, Virginia Beach, VA 23455, USA
- Correspondence:
| | - Margery L. Daughtrey
- Long Island Horticultural Research and Extension Center, Cornell University, Riverhead, NY 11901, USA
| | - Chuanxue Hong
- Hampton Roads Agricultural Research and Extension Center, Virginia Tech, Virginia Beach, VA 23455, USA
| |
Collapse
|
68
|
Luthe T, Kever L, Hänsch S, Hardy A, Tschowri N, Weidtkamp-Peters S, Frunzke J. Streptomyces development is involved in the efficient containment of viral infections. Microlife 2023; 4:uqad002. [PMID: 37223739 PMCID: PMC10117723 DOI: 10.1093/femsml/uqad002] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 12/09/2022] [Accepted: 01/13/2023] [Indexed: 05/25/2023]
Abstract
The formation of plaques represents the hallmark of phage infection visualizing the clearance of the bacterial lawn in structured environments. In this study, we have addressed the impact of cellular development on phage infection in Streptomyces undergoing a complex developmental life cycle. Analysis of plaque dynamics revealed, after a period of plaque size enlargement, a significant regrowth of transiently phage-resistant Streptomyces mycelium into the lysis zone. Analysis of Streptomyces venezuelae mutant strains defective at different stages of cellular development indicated that this regrowth was dependent on the onset of the formation of aerial hyphae and spores at the infection interface. Mutants restricted to vegetative growth (ΔbldN) featured no significant constriction of plaque area. Fluorescence microscopy further confirmed the emergence of a distinct zone of cells/spores with reduced cell permeability towards propidium iodide staining at the plaque periphery. Mature mycelium was further shown to be significantly less susceptible to phage infection, which is less pronounced in strains defective in cellular development. Transcriptome analysis revealed the repression of cellular development at the early stages of phage infection probably facilitating efficient phage propagation. We further observed an induction of the chloramphenicol biosynthetic gene cluster highlighting phage infection as a trigger of cryptic metabolism in Streptomyces. Altogether, our study emphasizes cellular development and the emergence of transient phage resistance as an important layer of Streptomyces antiviral immunity.
Collapse
Affiliation(s)
- Tom Luthe
- Institute of Bio- and Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich, 52425 Jülich, Germany
| | - Larissa Kever
- Institute of Bio- and Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich, 52425 Jülich, Germany
| | - Sebastian Hänsch
- Center for Advanced Imaging, Heinrich Heine Universität Düsseldorf, 40225 Düsseldorf, Germany
| | - Aël Hardy
- Institute of Bio- and Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich, 52425 Jülich, Germany
| | - Natalia Tschowri
- Institute of Microbiology, Leibniz Universität Hannover, 30419 Hannover, Germany
| | | | - Julia Frunzke
- Corresponding author: Institute of Bio- and Geosciences, IBG-1: Biotecnology, Forschungzentrum Jülich, 52425 Jülich, Germany. Tel: +49 2461 615430;
| |
Collapse
|
69
|
Ajmal M, Hussain A, Ali A, Chen H, Lin H. Strategies for Controlling the Sporulation in Fusarium spp. J Fungi (Basel) 2022; 9:jof9010010. [PMID: 36675831 PMCID: PMC9861637 DOI: 10.3390/jof9010010] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 12/16/2022] [Accepted: 12/18/2022] [Indexed: 12/24/2022] Open
Abstract
Fusarium species are the most destructive phytopathogenic and toxin-producing fungi, causing serious diseases in almost all economically important plants. Sporulation is an essential part of the life cycle of Fusarium. Fusarium most frequently produces three different types of asexual spores, i.e., macroconidia, chlamydospores, and microconidia. It also produces meiotic spores, but fewer than 20% of Fusaria have a known sexual cycle. Therefore, the asexual spores of the Fusarium species play an important role in their propagation and infection. This review places special emphasis on current developments in artificial anti-sporulation techniques as well as features of Fusarium's asexual sporulation regulation, such as temperature, light, pH, host tissue, and nutrients. This description of sporulation regulation aspects and artificial anti-sporulation strategies will help to shed light on the ways to effectively control Fusarium diseases by inhibiting the production of spores, which eventually improves the production of food plants.
Collapse
Affiliation(s)
- Maria Ajmal
- College of Life Sciences, Henan Agricultural University, 95 Wenhua Road, Zhengzhou 450002, China
| | - Adil Hussain
- Department of Entomology, Abdul Wali Khan University Mardan, Mardan 23200, Pakistan
| | - Asad Ali
- Department of Entomology, Abdul Wali Khan University Mardan, Mardan 23200, Pakistan
| | - Hongge Chen
- College of Life Sciences, Henan Agricultural University, 95 Wenhua Road, Zhengzhou 450002, China
| | - Hui Lin
- College of Life Sciences, Henan Agricultural University, 95 Wenhua Road, Zhengzhou 450002, China
- Correspondence:
| |
Collapse
|
70
|
Horvat S, Mahnic A, Makuc D, Pečnik K, Plavec J, Rupnik M. Children gut microbiota exhibits a different composition and metabolic profile after in vitro exposure to Clostridioides difficile and increases its sporulation. Front Microbiol 2022; 13:1042526. [PMID: 36569098 PMCID: PMC9780542 DOI: 10.3389/fmicb.2022.1042526] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Accepted: 11/17/2022] [Indexed: 12/13/2022] Open
Abstract
Clostridioides difficile (Clostridium difficile) infection (CDI) is one of the main public health concerns in adults, while children under 2 years of age are often colonized asymptomatically. In both adults and children, CDI is strongly associated with disturbances in gut microbiota. In this study, an in-vitro model of children gut microbiota was challenged with vegetative cells or a conditioned media of six different toxigenic C. difficile strains belonging to the ribotypes 027, 078, and 176. In the presence of C. difficile or conditioned medium the children gut microbiota diversity decreased and all main phyla (Bacteroidetes, Firmicutes, and Proteobacteria) were affected. The NMR metabolic spectra divided C. difficile exposed children gut microbiota into three clusters. The grouping correlated with nine metabolites (short chain fatty acids, ethanol, phenolic acids and tyramine). All strains were able to grow in the presence of children gut microbiota and showed a high sporulation rate of up to 57%. This high sporulation rate in combination with high asymptomatic carriage in children could contribute to the understanding of the reported role of children in C. difficile transmissions.
Collapse
Affiliation(s)
- Sabina Horvat
- Department of Microbiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia
| | - Aleksander Mahnic
- Department of Microbiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia,Centre for Medical Microbiology, National Laboratory of Health, Environment and Food, Maribor, Slovenia
| | - Damjan Makuc
- Slovenian NMR Centre, National Institute of Chemistry, Ljubljana, Slovenia
| | - Klemen Pečnik
- Slovenian NMR Centre, National Institute of Chemistry, Ljubljana, Slovenia
| | - Janez Plavec
- Slovenian NMR Centre, National Institute of Chemistry, Ljubljana, Slovenia
| | - Maja Rupnik
- Department of Microbiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia,Centre for Medical Microbiology, National Laboratory of Health, Environment and Food, Maribor, Slovenia,*Correspondence: Maja Rupnik,
| |
Collapse
|
71
|
Hughes AM, Darby JF, Dodson EJ, Wilson SJ, Turkenburg JP, Thomas GH, Wilkinson AJ. Peptide transport in Bacillus subtilis - structure and specificity in the extracellular solute binding proteins OppA and DppE. Microbiology (Reading) 2022; 168. [PMID: 36748525 DOI: 10.1099/mic.0.001274] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
Abstract
Peptide transporters play important nutritional and cell signalling roles in Bacillus subtilis, which are pronounced during stationary phase adaptations and development. Three high-affinity ATP-binding cassette (ABC) family transporters are involved in peptide uptake - the oligopeptide permease (Opp), another peptide permease (App) and a less well-characterized dipeptide permease (Dpp). Here we report crystal structures of the extracellular substrate binding proteins, OppA and DppE, which serve the Opp and Dpp systems, respectively. The structure of OppA was determined in complex with endogenous peptides, modelled as Ser-Asn-Ser-Ser, and with the sporulation-promoting peptide Ser-Arg-Asn-Val-Thr, which bind with K d values of 0.4 and 2 µM, respectively, as measured by isothermal titration calorimetry. Differential scanning fluorescence experiments with a wider panel of ligands showed that OppA has highest affinity for tetra- and penta-peptides. The structure of DppE revealed the unexpected presence of a murein tripeptide (MTP) ligand, l-Ala-d-Glu-meso-DAP, in the peptide binding groove. The mode of MTP binding in DppE is different to that observed in the murein peptide binding protein, MppA, from Escherichia coli, suggesting independent evolution of these proteins from an OppA-like precursor. The presence of MTP in DppE points to a role for Dpp in the uptake and recycling of cell wall peptides, a conclusion that is supported by analysis of the genomic context of dpp, which revealed adjacent genes encoding enzymes involved in muropeptide catabolism in a gene organization that is widely conserved in Firmicutes.
Collapse
Affiliation(s)
- Adam M Hughes
- Structural Biology Laboratory, Department of Chemistry, University of York, York YO10 5DD, UK
| | - John F Darby
- Structural Biology Laboratory, Department of Chemistry, University of York, York YO10 5DD, UK
| | - Eleanor J Dodson
- Structural Biology Laboratory, Department of Chemistry, University of York, York YO10 5DD, UK
| | - Samuel J Wilson
- Structural Biology Laboratory, Department of Chemistry, University of York, York YO10 5DD, UK
| | - Johan P Turkenburg
- Structural Biology Laboratory, Department of Chemistry, University of York, York YO10 5DD, UK
| | - Gavin H Thomas
- Department of Biology, University of York, York YO10 5DD, UK
| | - Anthony J Wilkinson
- Structural Biology Laboratory, Department of Chemistry, University of York, York YO10 5DD, UK
| |
Collapse
|
72
|
Zhao S, Zhang K, Lin C, Cheng M, Song J, Ru X, Wang Z, Wang W, Yang Q. Identification of a Novel Pleiotropic Transcriptional Regulator Involved in Sporulation and Secondary Metabolism Production in Chaetomium globosum. Int J Mol Sci 2022; 23:ijms232314849. [PMID: 36499180 PMCID: PMC9740612 DOI: 10.3390/ijms232314849] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2022] [Revised: 11/13/2022] [Accepted: 11/16/2022] [Indexed: 12/03/2022] Open
Abstract
Chaetoglobosin A (CheA), a well-known macrocyclic alkaloid with prominently highly antimycotic, antiparasitic, and antitumor properties, is mainly produced by Chaetomium globosum. However, a limited understanding of the transcriptional regulation of CheA biosynthesis has hampered its application and commercialization in agriculture and biomedicine. Here, a comprehensive study of the CgXpp1 gene, which encodes a basic helix-loop-helix family regulator with a putative role in the regulation of fungal growth and CheA biosynthesis, was performed by employing CgXpp1-disruption and CgXpp1-complementation strategies in the biocontrol species C. globosum. The results suggest that the CgXpp1 gene could be an indirect negative regulator in CheA production. Interestingly, knockout of CgXpp1 considerably increased the transcription levels of key genes and related regulatory factors associated with the CheA biosynthetic. Disruption of CgXpp1 led to a significant reduction in spore production and attenuation of cell development, which was consistent with metabolome analysis results. Taken together, an in-depth analysis of pleiotropic regulation influenced by transcription factors could provide insights into the unexplored metabolic mechanisms associated with primary and secondary metabolite production.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | | | - Qian Yang
- Correspondence: ; Tel.: +86-451-8640-2652
| |
Collapse
|
73
|
Du Q, Schaap P. Autophagy of the somatic stalk cells likely nurses the propagating spores of Dictyostelid social amoebas. Open Res Eur 2022; 2:104. [PMID: 36860212 PMCID: PMC7614253 DOI: 10.12688/openreseurope.14947.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Accepted: 11/14/2022] [Indexed: 11/24/2022]
Abstract
Background: Autophagy (self-feeding) assists survival of starving cells by partial self-digestion, while dormancy as cysts, spores or seeds enables long-term survival. Starving Dictyostelium amoebas construct multicellular fruiting bodies with spores and stalk cells, with many Dictyostelia still able to encyst individually like their single-celled ancestors. While autophagy mostly occurs in the somatic stalk cells, autophagy gene knock-outs in Dictyostelium discoideum ( D. discoideum) formed no spores and lacked cAMP induction of prespore gene expression. Methods: To investigate whether autophagy also prevents encystation, we knocked-out autophagy genes atg5 and atg7 in the dictyostelid Polysphondylium pallidum, which forms both spores and cysts. We measured spore and cyst differentiation and viability in the knock-out as well as stalk and spore gene expression and its regulation by cAMP. We tested a hypothesis that spores require materials derived from autophagy in stalk cells. Sporulation requires secreted cAMP acting on receptors and intracellular cAMP acting on PKA. We compared the morphology and viability of spores developed in fruiting bodies with spores induced from single cells by stimulation with cAMP and 8Br-cAMP, a membrane-permeant PKA agonist. Results: Loss of autophagy in P. pallidum reduced but did not prevent encystation. Stalk cells still differentiated but stalks were disorganised. However, no spores were formed at all and cAMP-induced prespore gene expression was lost. D. discoideum spores induced in vitro by cAMP and 8Br-cAMP were smaller and rounder than spores formed multicellularly and while they were not lysed by detergent they germinated not (strain Ax2) or poorly (strain NC4), unlike spores formed in fruiting bodies. Conclusions: The stringent requirement of sporulation on both multicellularity and autophagy, which occurs mostly in stalk cells, suggests that stalk cells nurse the spores through autophagy. This highlights autophagy as a major cause for somatic cell evolution in early multicellularity.
Collapse
Affiliation(s)
- Qingyou Du
- School of Life Sciences, University of Dundee, Dundee, Angus, DD15EH, UK
| | - Pauline Schaap
- School of Life Sciences, University of Dundee, Dundee, Angus, DD15EH, UK
| |
Collapse
|
74
|
Kasem SM, Mira NM, Mahfouz ME, Helal IB. In Vitro Study to Evaluate the Efficacy of Ultrasonicated Ethanolic Extract of Rosmarinus officinalis and its Chitosan-Based Nanoparticles Against Eimeria tenella Oocysts of Chickens. AAPS PharmSciTech 2022; 23:295. [PMID: 36329254 PMCID: PMC9633124 DOI: 10.1208/s12249-022-02445-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Accepted: 10/12/2022] [Indexed: 11/06/2022] Open
Abstract
In this study, chitosan nanoparticles (CsNPs) were used as nanocarrier for ultrasonicated ethanolic extract of Rosmarinus officinalis (UEERO) as a new nanoformulation against Eimeria tenella. Herein, CsNPs have been synthesized by ionic gelation method at pH 3 (CsNPs3) and pH 5 (CsNPs5), followed by characterization of morphology, size, polydispersity index (PDI), surface charge, and loading efficiency of UEERO. An in vitro sporulation inhibition assay (10, 5, 2.5, 1.25, 0.62, 0.31, 0.15, 0.07, 0.04, 0.02, and 0.01 mg/ml normal saline solution) against E. tenella was conducted. Results showed that free CsNPs and UEERO-CsNPs3/5 were cubic- and spherical-shaped with positive charge and average size of ~ 150.8 nm (314.4 nm) and 151.7 nm (321.1 nm), respectively. The total loading efficiency using UV–vis spectrophotometer, was 80.05 at pH 5 and 64.39% at pH 3. The in vitro sporulation inhibition assay revealed that UEERO, CsNPs3/5, and UEERO-CsNPs3/5 showed a potential inhibitory effect on sporulation (%), distortion in wall (%), and sporocyst abnormality (%) in a dose-dependent manner. Accordingly, the concentration (10 mg/ml) showed the best efficacy after 24 h in UEERO, free CsNPs, and UEERO-CsNPs. Moreover, UEERO-CsNPs3 and UEERO-CsNPs5 had stopped the sporulation (%) after 72 h. Taken all together, UEERO-CsNPs3 and UEERO-CsNPs5 are best effective against E. tenella in a dose-dependent manner in terms of sporulation (%), distortion in wall (%), and sporocysts abnormality.
Collapse
Affiliation(s)
- Shaimaa M Kasem
- Zoology Department, Faculty of Science, Kafrelsheikh University, Kafr ElSheikh, 33516, Egypt.
| | - Nabila M Mira
- Zoology Department, Faculty of Science, Kafrelsheikh University, Kafr ElSheikh, 33516, Egypt
| | - Magdy E Mahfouz
- Zoology Department, Faculty of Science, Kafrelsheikh University, Kafr ElSheikh, 33516, Egypt
| | - Ibrahim B Helal
- Zoology Department, Faculty of Science, Tanta University, EL Gharbia, 31527, Egypt
| |
Collapse
|
75
|
Arjes HA, Gui H, Porter R, Atolia E, Peters JM, Gross C, Kearns DB, Huang KC. Fatty Acid Synthesis Knockdown Promotes Biofilm Wrinkling and Inhibits Sporulation in Bacillus subtilis. mBio 2022; 13:e0138822. [PMID: 36069446 DOI: 10.1128/mbio.01388-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Many bacterial species typically live in complex three-dimensional biofilms, yet much remains unknown about differences in essential processes between nonbiofilm and biofilm lifestyles. Here, we created a CRISPR interference (CRISPRi) library of knockdown strains covering all known essential genes in the biofilm-forming Bacillus subtilis strain NCIB 3610 and investigated growth, biofilm colony wrinkling, and sporulation phenotypes of the knockdown library. First, we showed that gene essentiality is largely conserved between liquid and surface growth and between two media. Second, we quantified biofilm colony wrinkling using a custom image analysis algorithm and found that fatty acid synthesis and DNA gyrase knockdown strains exhibited increased wrinkling independent of biofilm matrix gene expression. Third, we designed a high-throughput screen to quantify sporulation efficiency after essential gene knockdown; we found that partial knockdowns of essential genes remained competent for sporulation in a sporulation-inducing medium, but knockdown of essential genes involved in fatty acid synthesis exhibited reduced sporulation efficiency in LB, a medium with generally lower levels of sporulation. We conclude that a subset of essential genes are particularly important for biofilm structure and sporulation/germination and suggest a previously unappreciated and multifaceted role for fatty acid synthesis in bacterial lifestyles and developmental processes. IMPORTANCE For many bacteria, life typically involves growth in dense, three-dimensional communities called biofilms that contain cells with differentiated roles held together by extracellular matrix. To examine how essential gene function varies between vegetative growth and the developmental states of biofilm formation and sporulation, we created and screened a comprehensive library of strains using CRISPRi to knockdown expression of each essential gene in the biofilm-capable Bacillus subtilis strain 3610. High-throughput assays and computational algorithms identified a subset of essential genes involved in biofilm wrinkling and sporulation and indicated that fatty acid synthesis plays important and multifaceted roles in bacterial development.
Collapse
|
76
|
Aynalem T, Meng L, Getachew A, Wu J, Yu H, Tan J, Li N, Xu S. StcU-2 Gene Mutation via CRISPR/Cas9 Leads to Misregulation of Spore-Cyst Formation in Ascosphaera apis. Microorganisms 2022; 10:2088. [PMID: 36296364 DOI: 10.3390/microorganisms10102088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 10/15/2022] [Accepted: 10/17/2022] [Indexed: 11/05/2022] Open
Abstract
Ascosphaera apis is the causative agent of honey bee chalkbrood disease, and spores are the only known source of infections. Interference with sporulation is therefore a promising way to manage A. apis. The versicolorin reductase gene (StcU-2) is a ketoreductase protein related to sporulation and melanin biosynthesis. To study the StcU-2 gene in ascospore production of A. apis, CRISPR/Cas9 was used, and eight hygromycin B antibiotic-resistant transformants incorporating enhanced green fluorescent protein (EGFP) were made and analyzed. PCR amplification, gel electrophoresis, and sequence analysis were used for target gene editing analysis and verification. The CRISPR/Cas9 editing successfully knocked out the StcU-2 gene in A. apis. StcU-2 mutants had shown albino and non-functional spore-cyst development and lost effective sporulation. In conclusion, editing of StcU-2 gene has shown direct relation with sporulation and melanin biosynthesis of A. apis; this effective sporulation reduction would reduce the spread and pathogenicity of A. apis to managed honey bee. To the best of our knowledge, this is the first time CRISPR/Cas9-mediated gene editing has been efficiently performed in A. apis, a fungal honey bee brood pathogen, which offers a comprehensive set of procedural references that contributes to A. apis gene function studies and consequent control of chalkbrood disease.
Collapse
|
77
|
Roberts DM, Anchimiuk A, Kloosterman TG, Murray H, Wu LJ, Gruber S, Errington J. Chromosome remodelling by SMC/Condensin in B. subtilis is regulated by monomeric Soj/ParA during growth and sporulation. Proc Natl Acad Sci U S A 2022; 119:e2204042119. [PMID: 36206370 PMCID: PMC9564211 DOI: 10.1073/pnas.2204042119] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Accepted: 09/09/2022] [Indexed: 11/18/2022] Open
Abstract
SMC complexes, loaded at ParB-parS sites, are key mediators of chromosome organization in bacteria. ParA/Soj proteins interact with ParB/Spo0J in a pathway involving adenosine triphosphate (ATP)-dependent dimerization and DNA binding, facilitating chromosome segregation in bacteria. In Bacillus subtilis, ParA/Soj also regulates DNA replication initiation and along with ParB/Spo0J is involved in cell cycle changes during endospore formation. The first morphological stage in sporulation is the formation of an elongated chromosome structure called an axial filament. Here, we show that a major redistribution of SMC complexes drives axial filament formation in a process regulated by ParA/Soj. Furthermore, and unexpectedly, this regulation is dependent on monomeric forms of ParA/Soj that cannot bind DNA or hydrolyze ATP. These results reveal additional roles for ParA/Soj proteins in the regulation of SMC dynamics in bacteria and yet further complexity in the web of interactions involving chromosome replication, segregation and organization, controlled by ParAB and SMC.
Collapse
Affiliation(s)
- David M. Roberts
- Centre for Bacterial Cell Biology, Biosciences Institute, Newcastle University, Newcastle upon Tyne, NE2 4AX, United Kingdom
| | - Anna Anchimiuk
- Department of Fundamental Microbiology, University of Lausanne, Bâtiment Biophore, 015 Lausanne, Switzerland
| | - Tomas G. Kloosterman
- Centre for Bacterial Cell Biology, Biosciences Institute, Newcastle University, Newcastle upon Tyne, NE2 4AX, United Kingdom
| | - Heath Murray
- Centre for Bacterial Cell Biology, Biosciences Institute, Newcastle University, Newcastle upon Tyne, NE2 4AX, United Kingdom
| | - Ling Juan Wu
- Centre for Bacterial Cell Biology, Biosciences Institute, Newcastle University, Newcastle upon Tyne, NE2 4AX, United Kingdom
| | - Stephan Gruber
- Department of Fundamental Microbiology, University of Lausanne, Bâtiment Biophore, 015 Lausanne, Switzerland
| | - Jeff Errington
- Centre for Bacterial Cell Biology, Biosciences Institute, Newcastle University, Newcastle upon Tyne, NE2 4AX, United Kingdom
| |
Collapse
|
78
|
Stragier P. To Feed or to Stick? Genomic Analysis Offers Clues for the Role of a Molecular Machine in Endospore Formers. J Bacteriol 2022; 204:e0018722. [PMID: 35913150 DOI: 10.1128/jb.00187-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Sporulation in Firmicutes starts with the formation of two adjacent cells and proceeds with the engulfment of the smaller one, the forespore, by the larger one, the mother cell. This critical step involves a core set of conserved genes, some transcribed in the forespore, such as spoIIQ, and others transcribed in the mother cell, such as the eight-gene spoIIIA operon. A model has been proposed in which the SpoIIIA and the SpoIIQ proteins form a channel connecting the mother cell and the forespore, playing the role of a secretion apparatus allowing the mother cell to nurture the fully engulfed forespore. Exploration of the genomes of Caryophanaceae and Erysipelotrichales has provided informations that are not fully congruent with data from Bacillaceae or Clostridia. The differences observed are correlated with specific physiological features, and alternate, not mutually exclusive views of the function of the SpoIIIA-SpoIIQ complex are presented.
Collapse
|
79
|
Chan H, Taib N, Gilmore MC, Mohamed AMT, Hanna K, Luhur J, Nguyen H, Hafiz E, Cava F, Gribaldo S, Rudner D, Rodrigues CDA. Genetic Screens Identify Additional Genes Implicated in Envelope Remodeling during the Engulfment Stage of Bacillus subtilis Sporulation. mBio 2022;:e0173222. [PMID: 36066101 DOI: 10.1128/mbio.01732-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
During bacterial endospore formation, the developing spore is internalized into the mother cell through a phagocytic-like process called engulfment, which involves synthesis and hydrolysis of peptidoglycan. Engulfment peptidoglycan hydrolysis requires the widely conserved and well-characterized DMP complex, composed of SpoIID, SpoIIM, and SpoIIP. In contrast, although peptidoglycan synthesis has been implicated in engulfment, the protein players involved are less well defined. The widely conserved SpoIIIAH-SpoIIQ interaction is also required for engulfment efficiency, functioning like a ratchet to promote membrane migration around the forespore. Here, we screened for additional factors required for engulfment using transposon sequencing in Bacillus subtilis mutants with mild engulfment defects. We discovered that YrvJ, a peptidoglycan hydrolase, and the MurA paralog MurAB, involved in peptidoglycan precursor synthesis, are required for efficient engulfment. Cytological analyses suggest that both factors are important for engulfment when the DMP complex is compromised and that MurAB is additionally required when the SpoIIIAH-SpoIIQ ratchet is abolished. Interestingly, despite the importance of MurAB for sporulation in B. subtilis, phylogenetic analyses of MurA paralogs indicate that there is no correlation between sporulation and the number of MurA paralogs and further reveal the existence of a third MurA paralog, MurAC, within the Firmicutes. Collectively, our studies identify two new factors that are required for efficient envelop remodeling during sporulation and highlight the importance of peptidoglycan precursor synthesis for efficient engulfment in B. subtilis and likely other endospore-forming bacteria.
Collapse
|
80
|
Zhang A, Lebrun R, Espinosa L, Galinier A, Pompeo F. PrkA is an ATP-dependent protease that regulates sporulation in Bacillus subtilis. J Biol Chem 2022; 298:102436. [PMID: 36041628 PMCID: PMC9512850 DOI: 10.1016/j.jbc.2022.102436] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 08/15/2022] [Accepted: 08/16/2022] [Indexed: 11/18/2022] Open
Abstract
In Bacillus subtilis, sporulation is a sequential and highly regulated process. Phosphorylation events by histidine kinases are key points in the phosphorelay that initiates sporulation, but serine/threonine protein kinases also play important auxiliary roles in this regulation. PrkA has been proposed to be a serine protein kinase expressed during the initiation of sporulation and involved in this differentiation process. Additionally, the role of PrkA in sporulation has been previously proposed to be mediated via the transition phase regulator ScoC, which in turn regulates the transcriptional factor σK and its regulon. However, the kinase activity of PrkA has not been clearly demonstrated, and neither its autophosphorylation nor phosphorylated substrates have been unambiguously established in B. subtilis. We demonstrated here that PrkA regulation of ScoC is likely indirect. Following bioinformatic homology searches, we revealed sequence similarities of PrkA with the ATPases associated with diverse cellular activities ATP-dependent Lon protease family. Here, we showed that PrkA is indeed able to hydrolyze α-casein, an exogenous substrate of Lon proteases, in an ATP-dependent manner. We also showed that this ATP-dependent protease activity is essential for PrkA function in sporulation since mutation in the Walker A motif leads to a sporulation defect. Furthermore, we found that PrkA protease activity is tightly regulated by phosphorylation events involving one of the Ser/Thr protein kinases of B. subtilis, PrkC. Taken together, our results clarify the key role of PrkA in the complex process of B. subtilis sporulation.
Collapse
Affiliation(s)
- Ao Zhang
- Laboratoire de Chimie Bactérienne, UMR 7283, IMM, CNRS, Aix-Marseille Université, Marseille, France
| | - Régine Lebrun
- Plateforme Protéomique de l'IMM, Marseille Protéomique (MaP), CNRS FR 3479, Aix-Marseille Université, Marseille, France
| | - Leon Espinosa
- Laboratoire de Chimie Bactérienne, UMR 7283, IMM, CNRS, Aix-Marseille Université, Marseille, France
| | - Anne Galinier
- Laboratoire de Chimie Bactérienne, UMR 7283, IMM, CNRS, Aix-Marseille Université, Marseille, France
| | - Frédérique Pompeo
- Laboratoire de Chimie Bactérienne, UMR 7283, IMM, CNRS, Aix-Marseille Université, Marseille, France.
| |
Collapse
|
81
|
Niehs SP, Scherlach K, Dose B, Uzum Z, Stinear TP, Pidot SJ, Hertweck C. A highly conserved gene locus in endofungal bacteria codes for the biosynthesis of symbiosis-specific cyclopeptides. PNAS Nexus 2022; 1:pgac152. [PMID: 36714835 PMCID: PMC9802438 DOI: 10.1093/pnasnexus/pgac152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Revised: 06/30/2022] [Accepted: 08/03/2022] [Indexed: 02/01/2023]
Abstract
The tight association of the pathogenic fungus Rhizopus microsporus and its toxin-producing, bacterial endosymbionts (Mycetohabitans spp.) is distributed worldwide and has significance for agriculture, food production, and human health. Intriguingly, the endofungal bacteria are essential for the propagation of the fungal host. Yet, little is known about chemical mediators fostering the symbiosis, and universal metabolites that support the mutualistic relationship have remained elusive. Here, we describe the discovery of a complex of specialized metabolites produced by endofungal bacteria under symbiotic conditions. Through full genome sequencing and comparative genomics of eight endofungal symbiont strains from geographically distant regions, we discovered a conserved gene locus (hab) for a nonribosomal peptide synthetase as a unifying trait. Bioinformatics analyses, targeted gene deletions, and chemical profiling uncovered unprecedented depsipeptides (habitasporins) whose structures were fully elucidated. Computational network analysis and labeling experiments granted insight into the biosynthesis of their nonproteinogenic building blocks (pipecolic acid and β-phenylalanine). Deletion of the hab gene locus was shown to impair the ability of the bacteria to enter their fungal host. Our study unveils a common principle of the endosymbiotic lifestyle of Mycetohabitans species and expands the repertoire of characterized chemical mediators of a globally occurring mutualistic association.
Collapse
Affiliation(s)
| | | | - Benjamin Dose
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology – Hans Knöll Institute (Leibniz-HKI), Beutenbergstr. 11a, 07745 Jena, Germany
| | - Zerrin Uzum
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology – Hans Knöll Institute (Leibniz-HKI), Beutenbergstr. 11a, 07745 Jena, Germany
| | - Timothy P Stinear
- Department of Microbiology and Immunology, Doherty Institute, University of Melbourne, 792 Elizabeth Street, Melbourne, 3000, Australia
| | - Sacha J Pidot
- Department of Microbiology and Immunology, Doherty Institute, University of Melbourne, 792 Elizabeth Street, Melbourne, 3000, Australia
| | | |
Collapse
|
82
|
Abstract
By entering a reversible state of reduced metabolic activity, dormant microorganisms are able to tolerate suboptimal conditions that would otherwise reduce their fitness. Dormancy may also benefit bacteria by serving as a refuge from parasitic infections. Here, we focus on dormancy in the Bacillota, where endospore development is transcriptionally regulated by the expression of sigma factors. A disruption of this process could influence the survivorship or reproduction of phages that infect spore-forming hosts with implications for coevolutionary dynamics. We characterized the distribution of sigma factors in over 4,000 genomes of diverse phages capable of infecting hosts that span the bacterial domain. From this, we identified homologs of sporulation-specific sigma factors in phages that infect spore-forming hosts. Unlike sigma factors required for phage reproduction, we provide evidence that sporulation-like sigma factors are nonessential for lytic infection. However, when expressed in the spore-forming Bacillus subtilis, some of these phage-derived sigma factors can activate the bacterial sporulation gene network and lead to a reduction in spore yield. Our findings suggest that the acquisition of host-like transcriptional regulators may allow phages to manipulate a complex and ancient trait in one of the most abundant cell types on Earth. IMPORTANCE As obligate parasites, phages exert strong top-down pressure on host populations with eco-evolutionary implications for community dynamics and ecosystem functioning. The process of phage infection, however, is constrained by bottom-up processes that influence the energetic and nutritional status of susceptible hosts. Many phages have acquired auxiliary genes from bacteria, which can be used to exploit host metabolism with consequences for phage fitness. In this study, we demonstrate that phages infecting spore-forming bacteria carry homologs of sigma factors, which their hosts use to orchestrate gene expression during spore development. By tapping into regulatory gene networks, phages may manipulate the physiology and survival strategies of nongrowing bacteria in ways that influence host-parasite coevolution.
Collapse
|
83
|
Ramšak B, Kück U. The Penicillium chrysogenum tom1 Gene a Major Target of Transcription Factor MAT1-1-1 Encodes a Nuclear Protein Involved in Sporulation. Front Fungal Biol 2022; 3:937023. [PMID: 37746180 PMCID: PMC10512297 DOI: 10.3389/ffunb.2022.937023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 06/13/2022] [Indexed: 09/26/2023]
Abstract
Fungal mating-type loci (MAT) encode transcription factors (TFs) MAT1-1-1 and MAT1-2-1, which govern sexual reproduction as well as other developmental processes. In Penicillium chrysogenum, the major producer of the beta-lactam antibiotic penicillin, a recent chromatin immunoprecipitation followed by sequencing (ChIP-seq) analysis identified 254 genes as direct targets of MAT1-1-1, many of which encode thus far uncharacterized proteins. Here, we characterized one of the major targets of MAT1-1-1, the tom1 gene, which encodes a protein highly conserved within the group of Eurotiomycetes fungi. Using fluorescence microscopy, we demonstrated binding of MAT1-1-1 to the tom1 promoter by reporter gene analysis. Extensive electrophoretic mobility shift assays (EMSAs) further showed that the promoter sequence of tom1 is bound in vitro by both MAT1-1-1 and MAT1-2-1. This indicated an interaction between the two TFs, which was verified by yeast two-hybrid analysis. The sequence of tom1 carries a nuclear localization sequence, and indeed its nuclear localization was verified by fluorescence microscopy. The in vivo function of tom1 was investigated using tom1 deletion strains, as well as a complementing strain where the wild-type tom1 gene was reintroduced. We found a clear sporulation defect in the deletion strain, which became more evident when the fungi were grown at an elevated temperature of 31°C.
Collapse
Affiliation(s)
| | - Ulrich Kück
- Allgemeine und Molekulare Botanik, Ruhr-Universität Bochum, Fakultät für Biologie und Biotechnologie, Bochum, Germany
| |
Collapse
|
84
|
Lamba S, Mundanda Muthappa D, Fanning S, Scannell AGM. Sporulation and Biofilms as Survival Mechanisms of Bacillus Species in Low-Moisture Food Production Environments. Foodborne Pathog Dis 2022; 19:448-462. [PMID: 35819266 DOI: 10.1089/fpd.2022.0006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Low-moisture foods (LMF) have clear advantages with respect to limiting the growth of foodborne pathogens. However, the incidences of Bacillus species in LMF reported in recent years raise concerns about food quality and safety, particularly when these foods are used as ingredients in more complex higher moisture products. This literature review describes the interlinked pathways of sporulation and biofilm formation by Bacillus species and their underlying molecular mechanisms that contribute to the bacteriums' persistence in LMF production environments. The long-standing challenges of food safety and quality in the LMF industry are also discussed with a focus on the bakery industry.
Collapse
Affiliation(s)
- Sakshi Lamba
- UCD Institute of Food and Health, Physiotherapy and Sports Science, University College Dublin, Dublin, Ireland.,UCD Centre for Food Safety, Physiotherapy and Sports Science, University College Dublin, Dublin, Ireland.,UCD School of Agriculture and Food Science, and Physiotherapy and Sports Science, University College Dublin, Dublin, Ireland
| | - Dechamma Mundanda Muthappa
- UCD Centre for Food Safety, Physiotherapy and Sports Science, University College Dublin, Dublin, Ireland.,UCD School of Agriculture and Food Science, and Physiotherapy and Sports Science, University College Dublin, Dublin, Ireland
| | - Séamus Fanning
- UCD Institute of Food and Health, Physiotherapy and Sports Science, University College Dublin, Dublin, Ireland.,UCD Centre for Food Safety, Physiotherapy and Sports Science, University College Dublin, Dublin, Ireland.,UCD School of Public Health, Physiotherapy and Sports Science, University College Dublin, Dublin, Ireland
| | - Amalia G M Scannell
- UCD Institute of Food and Health, Physiotherapy and Sports Science, University College Dublin, Dublin, Ireland.,UCD Centre for Food Safety, Physiotherapy and Sports Science, University College Dublin, Dublin, Ireland.,UCD School of Agriculture and Food Science, and Physiotherapy and Sports Science, University College Dublin, Dublin, Ireland
| |
Collapse
|
85
|
Chen Y, Wu Z, Dong L, You X, Ji Y, Liang Y. Yeast phospholipase D, Spo14, is not required for macroautophagy. Yeast 2022; 39:401-411. [PMID: 35711110 DOI: 10.1002/yea.3803] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 05/09/2022] [Accepted: 06/14/2022] [Indexed: 12/25/2022] Open
Abstract
Autophagy-related gene (Atg) proteins are key players in autophagy. Some proteins that function in vesicle trafficking and lipid metabolism are also involved in autophagy. The SPO14 in yeast, which encodes phospholipase D (PLD), is involved in membrane trafficking and plays a vital role in sporulation during meiosis. Crosstalk has been identified between autophagy and sporulation. Although the PLD is required for macroautophagy in mammals, its role in yeast macroautophagy remains unclear. We observed that Spo14 is not required for macroautophagy in yeast and that it is dispensable for Atg8 lipidation, which plays an important role in phagophore extension. Our results also revealed that green fluorescent protein (GFP)-Atg8 degradation is not completely blocked in atg1Δ/atg1Δ cells under sporulation condition. Therefore, Spo14 is not required for macroautophagy in yeast.
Collapse
Affiliation(s)
- Yun Chen
- Key Laboratory of Agricultural Environmental Microbiology of Ministry of Agriculture and Rural Affairs, College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| | - Zulin Wu
- Key Laboratory of Agricultural Environmental Microbiology of Ministry of Agriculture and Rural Affairs, College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| | - Lin Dong
- Key Laboratory of Agricultural Environmental Microbiology of Ministry of Agriculture and Rural Affairs, College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| | - Xia You
- Key Laboratory of Agricultural Environmental Microbiology of Ministry of Agriculture and Rural Affairs, College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| | - Yanling Ji
- Key Laboratory of Agricultural Environmental Microbiology of Ministry of Agriculture and Rural Affairs, College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| | - Yongheng Liang
- Key Laboratory of Agricultural Environmental Microbiology of Ministry of Agriculture and Rural Affairs, College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| |
Collapse
|
86
|
Clark AE, Adamson CC, Carothers KE, Roxas BAP, Viswanathan VK, Vedantam G. The Alternative Sigma Factor SigL Influences Clostridioides difficile Toxin Production, Sporulation, and Cell Surface Properties. Front Microbiol 2022; 13:871152. [PMID: 35633701 PMCID: PMC9130780 DOI: 10.3389/fmicb.2022.871152] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Accepted: 04/06/2022] [Indexed: 12/18/2022] Open
Abstract
The alternative sigma factor SigL (Sigma-54) facilitates bacterial adaptation to the extracellular environment by modulating the expression of defined gene subsets. A homolog of the gene encoding SigL is conserved in the diarrheagenic pathogen Clostridioides difficile. To explore the contribution of SigL to C. difficile biology, we generated sigL-disruption mutants (sigL::erm) in strains belonging to two phylogenetically distinct lineages—the human-relevant Ribotype 027 (strain BI-1) and the veterinary-relevant Ribotype 078 (strain CDC1). Comparative proteomics analyses of mutants and isogenic parental strains revealed lineage-specific SigL regulons. Concomitantly, loss of SigL resulted in pleiotropic and distinct phenotypic alterations in the two strains. Sporulation kinetics, biofilm formation, and cell surface-associated phenotypes were altered in CDC1 sigL::erm relative to the isogenic parent strain but remained unchanged in BI-1 sigL::erm. In contrast, secreted toxin levels were significantly elevated only in the BI-1 sigL::erm mutant relative to its isogenic parent. We also engineered SigL overexpressing strains and observed enhanced biofilm formation in the CDC1 background, and reduced spore titers as well as dampened sporulation kinetics in both strains. Thus, we contend that SigL is a key, pleiotropic regulator that dynamically influences C. difficile's virulence factor landscape, and thereby, its interactions with host tissues and co-resident microbes.
Collapse
Affiliation(s)
- Andrew E Clark
- School of Animal and Comparative Biomedical Sciences, Tucson, AZ, United States
| | - Chelsea C Adamson
- School of Animal and Comparative Biomedical Sciences, Tucson, AZ, United States
| | - Katelyn E Carothers
- School of Animal and Comparative Biomedical Sciences, Tucson, AZ, United States
| | | | - V K Viswanathan
- School of Animal and Comparative Biomedical Sciences, Tucson, AZ, United States.,Department of Immunobiology, University of Arizona, Tucson, AZ, United States.,BIO5 Institute for Collaborative Research, University of Arizona, Tucson, AZ, United States
| | - Gayatri Vedantam
- School of Animal and Comparative Biomedical Sciences, Tucson, AZ, United States.,Department of Immunobiology, University of Arizona, Tucson, AZ, United States.,BIO5 Institute for Collaborative Research, University of Arizona, Tucson, AZ, United States.,Southern Arizona VA Healthcare System, Tucson, AZ, United States
| |
Collapse
|
87
|
Donnelly ML, Shrestha S, Ribis JW, Kuhn P, Krasilnikov M, Alves Feliciano C, Shen A. Development of a Dual-Fluorescent-Reporter System in Clostridioides difficile Reveals a Division of Labor between Virulence and Transmission Gene Expression. mSphere 2022;:e0013222. [PMID: 35638354 DOI: 10.1128/msphere.00132-22] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The bacterial pathogen Clostridioides difficile causes gastroenteritis by producing toxins and transmits disease by making resistant spores. Toxin and spore production are energy-expensive processes that are regulated by multiple transcription factors in response to many environmental inputs. While toxin and sporulation genes are both induced in only a subset of C. difficile cells, the relationship between these two subpopulations remains unclear. To address whether C. difficile coordinates the generation of these subpopulations, we developed a dual-transcriptional-reporter system that allows toxin and sporulation gene expression to be simultaneously visualized at the single-cell level using chromosomally encoded mScarlet and mNeonGreen fluorescent transcriptional reporters. We then adapted an automated image analysis pipeline to quantify toxin and sporulation gene expression in thousands of individual cells under different medium conditions and in different genetic backgrounds. These analyses revealed that toxin and sporulation gene expression rarely overlap during growth on agar plates, whereas broth culture increases this overlap. Our results suggest that certain growth conditions promote a “division of labor” between transmission and virulence gene expression, highlighting how environmental inputs influence these subpopulations. Our data further suggest that the RstA transcriptional regulator skews the population to activate sporulation genes rather than toxin genes. Given that recent work has revealed population-wide heterogeneity for numerous cellular processes in C. difficile, we anticipate that our dual-reporter system will be broadly useful for determining the overlap between these subpopulations. IMPORTANCEClostridioides difficile is an important nosocomial pathogen that causes severe diarrhea by producing toxins and transmits disease by producing spores. While both processes are crucial for C. difficile disease, only a subset of cells express toxins and/or undergo sporulation. Whether C. difficile coordinates the subset of cells inducing these energy-expensive processes remains unknown. To address this question, we developed a dual-fluorescent-reporter system coupled with an automated image analysis pipeline to rapidly compare the expression of two genes of interest across thousands of cells. Using this system, we discovered that certain growth conditions, particularly growth on agar plates, induce a “division of labor” between toxin and sporulation gene expression. Since C. difficile exhibits phenotypic heterogeneity for numerous vital cellular processes, this novel dual-reporter system will enable future studies aimed at understanding how C. difficile coordinates various subpopulations throughout its infectious disease cycle.
Collapse
|
88
|
Feng W, Argüello-Miranda O, Qian S, Wang F. Cdc14 plans autophagy for meiotic cell divisions. Autophagy 2022; 18:1481-1482. [PMID: 35617128 DOI: 10.1080/15548627.2022.2080956] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
Abstract
The role of meiotic proteasome-mediated degradation has been extensively studied. At the same time, macroautophagy/autophagy only emerged recently as an essential regulator for meiosis progression. Our recent publication showed that autophagy in meiotic cells exhibits a temporal pattern distinct from that in quiescent cells or mitotic cells under prolonged starvation. Importantly, autophagic activity oscillates during meiotic cell divisions, i.e., meiosis I and meiosis II, which can accelerate meiotic progression and increase sporulation efficiency. Our in vitro and in vivo assays revealed that the conserved phosphatase Cdc14 stimulates autophagy initiation during meiotic divisions, specifically in anaphase I and II, when a subpopulation of active Cdc14 relocates to the cytosol and interacts with phagophore assembly sites (PAS) triggering the dephosphorylation of Atg13 to stimulate Atg1 kinase activity and autophagy. Together, our findings reveal a mechanism for the coordination of autophagy activity in the context of meiosis progression.
Collapse
Affiliation(s)
- Wenzhi Feng
- Department of Cell Biology, UT Southwestern Medical Center, Dallas, TX, USA
| | | | - Suhong Qian
- Department of Cell Biology, UT Southwestern Medical Center, Dallas, TX, USA
| | - Fei Wang
- Department of Cell Biology, UT Southwestern Medical Center, Dallas, TX, USA.,Lead Contact
| |
Collapse
|
89
|
Li L, Jin J, Hu H, Deveau IF, Foley SL, Chen H. Optimization of Sporulation and Purification Methods for Sporicidal Efficacy Assessment on Bacillus Spores. J Ind Microbiol Biotechnol 2022; 49:6590047. [PMID: 35595506 DOI: 10.1093/jimb/kuac014] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2022] [Accepted: 05/03/2022] [Indexed: 11/14/2022]
Abstract
Validating the efficacy of sporicidal agents is a critical step in current good manufacturing practices for disinfection requirements. A limitation is that the poor quality of spores can lead to false positive sporicidal results. The aim of this study was to explore optimal sporulation and purification methods in Bacillus spores. Spores of seven Bacillus strains were produced in five different sporulation media. After density centrifugation, spore yields were measured by phase-contrast microscopy and enumeration assays. Effects of purification methods including heat, sonication and lysozyme, and maturation on spore qualities were determined by sodium hypochlorite sporicidal assay. Difco Sporulation Media was identified as the preferred sporulation medium for four out of seven tested Bacillus strains. Sporulation rates in B. cereus, B. sphaericus, and B. thuringiensis were higher at 30°C than the rates at 37°C at a difference of 5%, 65%, and 20%, respectively. B. licheniformis favored Mn2+-amended 10% Columbia Broth at 37°C for sporulation with 40-72% higher sporulation rates than other media. The maximum sporulation rates of B. cereus and B. thuringiensis were observed on double-strength Schaeffer's-glucose broth. All studied purification methods improved the spore purity with strain variations. However, intense heat (80°C for 20 min) and lysozyme (100 μg/mL) treatment impaired the spore quality of specific Bacillus strains by sensitizing them against sodium hypochlorite. The length of maturation period had impact on the spore resistance, and the most optimal maturation periods ranged from 7 to 21 days in Bacillus strains. The results of this study will pave the way for further evaluation of sporicidal activity of disinfectants.
Collapse
Affiliation(s)
- Liang Li
- Division of Microbiology, National Center for Toxicological Research, U.S. FDA, Jefferson, AR, USA
| | - Jinshan Jin
- Division of Microbiology, National Center for Toxicological Research, U.S. FDA, Jefferson, AR, USA
| | - Haijing Hu
- Office of Dietary Supplement Programs, Center for Food Safety and Applied Nutrition, U.S. FDA, College Park, MD, USA
| | - Ian F Deveau
- Office of Compounding Quality and Compliance, Center for Drug Evaluation and Research, U.S. FDA, Silver Spring, MD, USA
| | - Steven L Foley
- Division of Microbiology, National Center for Toxicological Research, U.S. FDA, Jefferson, AR, USA
| | - Huizhong Chen
- Division of Microbiology, National Center for Toxicological Research, U.S. FDA, Jefferson, AR, USA
| |
Collapse
|
90
|
Abstract
During sporulation, Bacillus subtilis undergoes an atypical cell division that requires overriding mechanisms that protect chromosomes from damage and ensure inheritance by daughter cells. Instead of assembling between segregated chromosomes at midcell, the FtsZ-ring coalesces polarly, directing division over one chromosome. The DNA-binding protein RefZ facilitates the timely assembly of polar Z-rings and partially defines the region of chromosome initially captured in the forespore. RefZ binds to motifs (RBMs) located proximal to the origin of replication (oriC). Although refZ and the RBMs are conserved across the Bacillus genus, a refZ deletion mutant sporulates with wild-type efficiency, so the functional significance of RefZ during sporulation remains unclear. To further investigate RefZ function, we performed a candidate-based screen for synthetic sporulation defects by combining ΔrefZ with deletions of genes previously implicated in FtsZ regulation and/or chromosome capture. Combining ΔrefZ with deletions of ezrA, sepF, parA, or minD did not detectably affect sporulation. In contrast, a ΔrefZ Δnoc mutant exhibited a sporulation defect, revealing a genetic interaction between RefZ and Noc. Using reporters of sporulation progression, we determined the ΔrefZ Δnoc mutant exhibited sporulation delays after Spo0A activation but prior to late sporulation, with a subset of cells failing to divide polarly or activate the first forespore-specific sigma factor, SigF. The ΔrefZ Δnoc mutant also exhibited extensive dysregulation of cell division, producing cells with extra, misplaced, or otherwise aberrant septa. Our results reveal a previously unknown epistatic relationship that suggests refZ and noc contribute synthetically to regulating cell division and supporting spore development. IMPORTANCE The DNA-binding protein RefZ and its binding sites (RBMs) are conserved in sequence and location on the chromosome across the Bacillus genus and contribute to the timing of polar FtsZ-ring assembly during sporulation. Only a small number of noncoding and nonregulatory DNA motifs are known to be conserved in chromosomal position in bacteria, suggesting there is strong selective pressure for their maintenance; however, a refZ deletion mutant sporulates efficiently, providing no clues as to their functional significance. Here, we find that in the absence of the nucleoid occlusion factor Noc, deletion of refZ results in a sporulation defect characterized by developmental delays and aberrant divisions.
Collapse
|
91
|
Zhang J, Zhu B, Li X, Xu X, Li D, Zeng F, Zhou C, Liu Y, Li Y, Lu F. Multiple Modular Engineering of Bacillus Amyloliquefaciens Cell Factories for Enhanced Production of Alkaline Proteases From B. Clausii. Front Bioeng Biotechnol 2022; 10:866066. [PMID: 35497355 PMCID: PMC9046661 DOI: 10.3389/fbioe.2022.866066] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Accepted: 03/29/2022] [Indexed: 11/13/2022] Open
Abstract
Bacillus amyloliquefaciens is a generally recognized as safe (GRAS) microorganism that presents great potential for the production of heterologous proteins. In this study, we performed genomic and comparative transcriptome to investigate the critical modular in B. amyloliquefaciens on the production of heterologous alkaline proteases (AprE). After investigation, it was concluded that the key modules affecting the production of alkaline protease were the sporulation germination module (Module I), extracellular protease synthesis module (Module II), and extracellular polysaccharide synthesis module (Module III) in B. amyloliquefaciens. In Module I, AprE yield for mutant BA ΔsigF was 25.3% greater than that of BA Δupp. Combining Module I synergistically with mutation of extracellular proteases in Module II significantly increased AprE production by 36.1% compared with production by BA Δupp. In Module III, the mutation of genes controlling extracellular polysaccharides reduced the viscosity and the accumulation of sediment, and increased the rate of dissolved oxygen in fermentation. Moreover, AprE production was 39.6% higher than in BA Δupp when Modules I, II and III were engineered in combination. This study provides modular engineering strategies for the modification of B. amyloliquefaciens for the production of alkaline proteases.
Collapse
Affiliation(s)
- Jinfang Zhang
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Key Laboratory of Industrial Microbiology, the College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China
| | - Baoyue Zhu
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Key Laboratory of Industrial Microbiology, the College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China
| | - Xinyue Li
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Key Laboratory of Industrial Microbiology, the College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China
| | - Xiaojian Xu
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Key Laboratory of Industrial Microbiology, the College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China
| | - Dengke Li
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Key Laboratory of Industrial Microbiology, the College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China
| | - Fang Zeng
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Key Laboratory of Industrial Microbiology, the College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China
| | - Cuixia Zhou
- School of Biology and Brewing Engineering, Taishan University, Taian, China
| | - Yihan Liu
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Key Laboratory of Industrial Microbiology, the College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China
| | - Yu Li
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Key Laboratory of Industrial Microbiology, the College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China
| | - Fuping Lu
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Key Laboratory of Industrial Microbiology, the College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China
| |
Collapse
|
92
|
Gao Y, Barajas-Ornelas RDC, Amon JD, Ramírez-Guadiana FH, Alon A, Brock KP, Marks DS, Kruse AC, Rudner DZ. The SpoVA membrane complex is required for dipicolinic acid import during sporulation and export during germination. Genes Dev 2022; 36:634-646. [PMID: 35654455 PMCID: PMC9186386 DOI: 10.1101/gad.349488.122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Accepted: 05/16/2022] [Indexed: 11/24/2022]
Abstract
In response to starvation, endospore-forming bacteria differentiate into stress-resistant spores that can remain dormant for years yet rapidly germinate and resume growth in response to nutrients. The small molecule dipicolinic acid (DPA) plays a central role in both the stress resistance of the dormant spore and its exit from dormancy during germination. The spoVA locus is required for DPA import during sporulation and has been implicated in its export during germination, but the molecular bases are unclear. Here, we define the minimal set of proteins encoded in the Bacillus subtilis spoVA operon required for DPA import and demonstrate that these proteins form a membrane complex. Structural modeling of these components combined with mutagenesis and in vivo analysis reveal that the C and Eb subunits form a membrane channel, while the D subunit functions as a cytoplasmic plug. We show that point mutations that impair the interactions between D and the C-Eb membrane complex reduce the efficiency of DPA import during sporulation and reciprocally accelerate DPA release during germination. Our data support a model in which DPA transport into spores involves cycles of unplugging and then replugging the C-Eb membrane channel, while nutrient detection during germination triggers DPA release by unplugging it.
Collapse
Affiliation(s)
- Yongqiang Gao
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts 02115, USA
| | | | - Jeremy D Amon
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts 02115, USA
| | | | - Assaf Alon
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Kelly P Brock
- Department of Systems Biology, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Debora S Marks
- Department of Systems Biology, Harvard Medical School, Boston, Massachusetts 02115, USA.,Broad Institute of Harvard and Massachusetts Institute of Technology, Cambridge, Massachusetts 02142, USA
| | - Andrew C Kruse
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - David Z Rudner
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts 02115, USA
| |
Collapse
|
93
|
Yu Z, Fu Y, Zhang W, Zhu L, Yin W, Chou SH, He J. The RNA Chaperone Protein Hfq Regulates the Characteristic Sporulation and Insecticidal Activity of Bacillus thuringiensis. Front Microbiol 2022; 13:884528. [PMID: 35479624 PMCID: PMC9037596 DOI: 10.3389/fmicb.2022.884528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2022] [Accepted: 03/15/2022] [Indexed: 11/13/2022] Open
Abstract
Bacillus thuringiensis (Bt) is one of the most widely used bio-insecticides at present. It can produce many virulence factors and insecticidal crystal proteins during growth and sporulation. Hfq, on the other hand, is a bacterial RNA chaperone that can regulate the function of different kinds of RNAs, thereby affecting various bacterial phenotypes. To further explore the physiological functions of Hfq in Bt, we took BMB171 as the starting strain, knocked out one, two, or three hfq genes in its genome in different combinations, and compared the phenotypic differences between the deletion mutant strains and the starting strain. We did observe significant changes in several phenotypes, including motility, biofilm formation, sporulation, and insecticidal activity against cotton bollworm, among others. Afterward, we found through transcriptome studies that when all hfq genes were deleted, 32.5% of the genes in Bt were differentially transcribed, with particular changes in the sporulation-related and virulence-related genes. The above data demonstrated that Hfq plays a pivotal role in Bt and can regulate its various physiological functions. Our study on the regulatory mechanism of Hfq in Bt, especially the mining of the regulatory network of its sporulation and insecticidal activity, could lay a theoretical foundation for the better utilization of Bt as an effective insecticide.
Collapse
Affiliation(s)
- Zhaoqing Yu
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Yang Fu
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China.,National Engineering Research Center of Edible Fungi, Institute of Edible Fungi, Shanghai Academy of Agricultural Sciences, Shanghai, China
| | - Wei Zhang
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Li Zhu
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Wen Yin
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Shan-Ho Chou
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Jin He
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| |
Collapse
|
94
|
Olenic S, Heo L, Feig M, Kroos L. Inhibitory proteins block substrate access by occupying the active site cleft of Bacillus subtilis intramembrane protease SpoIVFB. eLife 2022; 11:74275. [PMID: 35471152 PMCID: PMC9042235 DOI: 10.7554/elife.74275] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Accepted: 03/25/2022] [Indexed: 12/16/2022] Open
Abstract
Intramembrane proteases (IPs) function in numerous signaling pathways that impact health, but elucidating the regulation of membrane-embedded proteases is challenging. We examined inhibition of intramembrane metalloprotease SpoIVFB by proteins BofA and SpoIVFA. We found that SpoIVFB inhibition requires BofA residues in and near a predicted transmembrane segment (TMS). This segment of BofA occupies the SpoIVFB active site cleft based on cross-linking experiments. SpoIVFB inhibition also requires SpoIVFA. The inhibitory proteins block access of the substrate N-terminal region to the membrane-embedded SpoIVFB active site, based on additional cross-linking experiments; however, the inhibitory proteins did not prevent interaction between the substrate C-terminal region and the SpoIVFB soluble domain. We built a structural model of SpoIVFB in complex with BofA and parts of SpoIVFA and substrate, using partial homology and constraints from cross-linking and co-evolutionary analyses. The model predicts that conserved BofA residues interact to stabilize a TMS and a membrane-embedded C-terminal region. The model also predicts that SpoIVFA bridges the BofA C-terminal region and SpoIVFB, forming a membrane-embedded inhibition complex. Our results reveal a novel mechanism of IP inhibition with clear implications for relief from inhibition in vivo and design of inhibitors as potential therapeutics.
Collapse
Affiliation(s)
- Sandra Olenic
- Michigan State University, East Lansing, United States
| | - Lim Heo
- Michigan State University, East Lansing, United States
| | - Michael Feig
- Michigan State University, East Lansing, United States
| | - Lee Kroos
- Michigan State University, East Lansing, United States
| |
Collapse
|
95
|
Abstract
The ability of the anaerobic gastrointestinal pathogen Clostridioides difficile to survive outside the host relies on the formation of dormant endospores. Spore formation is contingent on the activation of a conserved transcription factor, Spo0A, by phosphorylation. Multiple kinases and phosphatases regulate Spo0A activity in other spore-forming organisms; however, these factors are not well conserved in C. difficile. Previously, we discovered that deletion of a predicted histidine kinase, CD1492, increases sporulation, indicating that CD1492 inhibits C. difficile spore formation. In this study, we investigate the functions of additional predicted orphan histidine kinases CD2492, CD1579, and CD1949, which are hypothesized to regulate Spo0A phosphorylation. Disruption of CD2492 also increased sporulation frequency, similarly to the CD1492 mutant and in contrast to a previous study. A CD1492 CD2492 mutant phenocopied the sporulation and gene expression patterns of the single mutants, suggesting that these proteins function in the same genetic pathway to repress sporulation. Deletion of CD1579 variably increased sporulation frequency; however, knockdown of CD1949 expression did not influence sporulation. We provide evidence that CD1492, CD2492, and CD1579 function as phosphatases, as mutation of the conserved histidine residue for phosphate transfer abolished CD2492 function, and expression of the CD1492 or CD2492 histidine site-directed mutants or the wild-type CD1579 allele in a parent strain resulted in a dominant-negative hypersporulation phenotype. Altogether, at least three predicted histidine kinases, CD1492, CD2492, and CD1579 (herein, PtpA, PtpB and PtpC), repress C. difficile sporulation initiation by regulating activity of Spo0A. IMPORTANCE The formation of inactive spores is critical for the long-term survival of the gastrointestinal pathogen Clostridioides difficile. The onset of sporulation is controlled by the master regulator of sporulation, Spo0A, which is activated by phosphorylation. Multiple kinases and phosphatases control Spo0A phosphorylation; however, this regulatory pathway is not defined in C. difficile. We show that two predicted histidine kinase proteins, CD1492 (PtpA) and CD2492 (PtpB), function in the same regulatory pathway to repress sporulation by preventing Spo0A phosphorylation. We show that another predicted histidine kinase protein, CD1579 (PtpC), also represses sporulation and present evidence that a fourth predicted histidine kinase protein, CD1949, does not impact sporulation. These results support the idea that C. difficile inhibits sporulation initiation through multiple phosphatases.
Collapse
|
96
|
Abe K, Kato H, Hasegawa Y, Yamamoto T, Nomura N, Obana N. Visualization and characterization of spore morphogenesis in Paenibacillus polymyxa ATCC39564. J GEN APPL MICROBIOL 2022; 68:79-86. [PMID: 35418538 DOI: 10.2323/jgam.2021.10.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Paenibacillus polymyxa is a spore-forming Gram-positive bacterial species. Both its sporulation process and the spore properties are poorly understood. Here, we investigated sporulation in P. polymyxa ATCC39564. When cultured at 37℃ for 24 h in sporulation medium, more than 80% of the total cells in the culture were spores. Time-lapse imaging revealed that cellular morphological changes during sporulation of P. polymyxa were highly similar to those of B. subtilis. We demonstrated that genetic deletion of spo0A, sigE, sigF, sigG, or sigK, which are highly conserved transcriptional regulators in spore forming bacteria, abolished spore formation. In P. polymyxa, spo0A was required for cell growth in sporulation medium, as well as for the initiation of sporulation. The sigE and sigF mutants formed abnormal multiple asymmetric septa during the early stage of sporulation. The sigG and sigK mutants formed forespores in the sporangium, but they did not become mature. Moreover, fluorescence reporter analysis confirmed compartment-specific gene expression of spoIID and spoVFA in the mother cell and spoIIQ and sspF in the forespore. Transmission electron microscopy imaging revealed that P. polymyxa produces multilayered endospores but lacking a balloon-shaped exosporium. Our results indicate that spore morphogenesis is conserved between P. polymyxa and B. subtilis. However, P. polymyxa genomes lack many homologues encoding spore-coat proteins that are found in B. subtills, suggesting that there are differences in the spore coat composition and surface structure between P. polymyxa and B. subtilis.
Collapse
Affiliation(s)
- Kimihiro Abe
- Faculty of Life and Environmental Sciences, University of Tsukuba
| | - Hiroko Kato
- Gradudate School of Life and Environmental Sciences, University of Tsukuba
| | - Yuta Hasegawa
- Gradudate School of Life and Environmental Sciences, University of Tsukuba
| | - Tatsuya Yamamoto
- Faculty of Life and Environmental Sciences, University of Tsukuba
| | - Nobuhiko Nomura
- Faculty of Life and Environmental Sciences, University of Tsukuba.,Microbiology Research Center for Sustainability, University of Tsukuba
| | - Nozomu Obana
- Microbiology Research Center for Sustainability, University of Tsukuba.,Transborder Medical Research Center, Faculty of Medicine, University of Tsukuba
| |
Collapse
|
97
|
Zhou B, Alon S, Rao L, Sinai L, Ben-Yehuda S. Reviving the view: evidence that macromolecule synthesis fuels bacterial spore germination. Microlife 2022; 3:uqac004. [PMID: 37223344 PMCID: PMC10117790 DOI: 10.1093/femsml/uqac004] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 03/13/2022] [Accepted: 04/06/2022] [Indexed: 05/25/2023]
Abstract
The Gram positive bacterium Bacillus subtilis and its relatives are capable of forming a durable dormant long-lasting spore. Although spores can remain dormant for years, they possess the remarkable capacity to rapidly resume life and convert into actively growing cells. This cellular transition initiates with a most enigmatic irreversible event, termed germination, lasting only for a few minutes. Germination is typified by a morphological conversion that culminates in loss of spore resilient properties. Yet, the molecular events occurring during this brief critical phase are largely unknown. The current widely accepted view considers germination to occur without the need for any macromolecule synthesis; however, accumulating data from our laboratory and others, highlighted here, provide evidence that both transcription and translation occur during germination and are required for its execution. We further underline numerous overlooked studies, conducted mainly during the 1960s-1970s, reinforcing this notion. We propose to revisit the fascinating process of spore germination and redefine it as a pathway involving macromolecule synthesis. We expect our perspective to shed new light on the awakening process of a variety of spore-forming environmental, commensal, and pathogenic bacteria and possibly be applicable to additional organisms displaying a quiescent life form.
Collapse
Affiliation(s)
- Bing Zhou
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, POB 12272, The Hebrew University of Jerusalem, 91120 Jerusalem, Israel
| | - Sima Alon
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, POB 12272, The Hebrew University of Jerusalem, 91120 Jerusalem, Israel
| | | | - Lior Sinai
- Corresponding author:Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, POB 12272, The Hebrew University of Jerusalem, 91120, Jerusalem, Israel.
| | - Sigal Ben-Yehuda
- Corresponding author:Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, POB 12272, The Hebrew University of Jerusalem, 91120, Jerusalem, Israel.
| |
Collapse
|
98
|
Martinko K, Ivanković S, Đermić E, Đermić D. In vitro antifungal effect of phenylboronic and boric acid on Alternaria alternata. Arh Hig Rada Toksikol 2022; 73:83-7. [PMID: 35390244 DOI: 10.2478/aiht-2022-73-3620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 03/01/2022] [Indexed: 11/30/2022] Open
Abstract
The ascomycete fungus Alternaria alternata causes early blight, one of economically the most important tomato diseases. Due to frequent use of fungicides, A. alternata has developed resistance with negative economic and environmental consequences. Research of new ways to control fungal pathogens has turned its eye to environmentally friendly chemicals with low toxicity such as boronic acids. The aim of our study was therefore to test the antifungal effects of phenylboronic and boric acid in vitro on A. alternata. We isolated the pathogen from a symptomatic tomato plant and determined the minimum inhibitory concentration of phenylboronic and boric acid on A. alternata mycelial growth using the poisoned food technique. The antifungal effect was tested on a wide range of phenylboronic and boric acid concentrations (from 0.04 % to 0.3 %) applied separately to agar with mycelial disc of the pathogen. After five days of incubation, phenylboronic acid at low concentration (0.05 %) completely inhibited mycelial growth. Boric acid, in turn, did not significantly slow down mycelial growth but did reduce sporulation and confirmed its fungistatic effect. Our findings point to the potential use of phenylboronic acid to control phytopathogenic fungi. This is, to our knowledge, the first report on its antifungal effect on an agriculturally important pathogen in vitro. Moreover, since A. alternata is also a human pathogen, these results may have clinical ramifications.
Collapse
|
99
|
Krach EK, Skaro M, Wu Y, Arnold J. Characterizing the gene-environment interaction underlying natural morphological variation in Neurospora crassa conidiophores using high-throughput phenomics and transcriptomics. G3 (Bethesda) 2022; 12:jkac050. [PMID: 35293585 PMCID: PMC8982394 DOI: 10.1093/g3journal/jkac050] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/23/2022] [Accepted: 02/21/2022] [Indexed: 11/12/2022]
Abstract
Neurospora crassa propagates through dissemination of conidia, which develop through specialized structures called conidiophores. Recent work has identified striking variation in conidiophore morphology, using a wild population collection from Louisiana, United States of America to classify 3 distinct phenotypes: Wild-Type, Wrap, and Bulky. Little is known about the impact of these phenotypes on sporulation or germination later in the N. crassa life cycle, or about the genetic variation that underlies them. In this study, we show that conidiophore morphology likely affects colonization capacity of wild N. crassa isolates through both sporulation distance and germination on different carbon sources. We generated and crossed homokaryotic strains belonging to each phenotypic group to more robustly fit a model for and estimate heritability of the complex trait, conidiophore architecture. Our fitted model suggests at least 3 genes and 2 epistatic interactions contribute to conidiophore phenotype, which has an estimated heritability of 0.47. To uncover genes contributing to these phenotypes, we performed RNA-sequencing on mycelia and conidiophores of strains representing each of the 3 phenotypes. Our results show that the Bulky strain had a distinct transcriptional profile from that of Wild-Type and Wrap, exhibiting differential expression patterns in clock-controlled genes (ccgs), the conidiation-specific gene con-6, and genes implicated in metabolism and communication. Combined, these results present novel ecological impacts of and differential gene expression underlying natural conidiophore morphological variation, a complex trait that has not yet been thoroughly explored.
Collapse
Affiliation(s)
- Emily K Krach
- Genetics Department, University of Georgia, Athens, GA 30602, USA
| | - Michael Skaro
- Institute of Bioinformatics, University of Georgia, Athens, GA 30602, USA
| | - Yue Wu
- Institute of Bioinformatics, University of Georgia, Athens, GA 30602, USA
| | - Jonathan Arnold
- Genetics Department, University of Georgia, Athens, GA 30602, USA
- Institute of Bioinformatics, University of Georgia, Athens, GA 30602, USA
| |
Collapse
|
100
|
Komachi K, Burgess SM. The Nup2 meiotic-autonomous region relieves inhibition of Nup60 to promote progression of meiosis and sporulation in Saccharomyces cerevisiae. Genetics 2022; 221:6550504. [PMID: 35302609 PMCID: PMC9071577 DOI: 10.1093/genetics/iyac045] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Accepted: 03/10/2022] [Indexed: 11/22/2022] Open
Abstract
During meiosis, chromosomes undergo dramatic changes in structural organization, nuclear positioning, and motion. Although the nuclear pore complex has been shown to affect genome organization and function in vegetative cells, its role in meiotic chromosome dynamics has remained largely unexplored. Recent work in the budding yeast Saccharomyces cerevisiae demonstrated that the mobile nucleoporin Nup2 is required for normal progression through meiosis I prophase and sporulation in strains where telomere-led chromosome movement has been compromised. The meiotic-autonomous region, a short fragment of Nup2 responsible for its role in meiosis, was shown to localize to the nuclear envelope via Nup60 and to bind to meiotic chromosomes. To understand the relative contribution these 2 activities have on meiotic-autonomous region function, we first carried out a screen for meiotic-autonomous region mutants defective in sporulation and found that all the mutations disrupt interaction with both Nup60 and meiotic chromosomes. Moreover, nup60 mutants phenocopy nup2 mutants, exhibiting similar nuclear division kinetics, sporulation efficiencies, and genetic interactions with mutations that affect the telomere bouquet. Although full-length Nup60 requires Nup2 for function, removal of Nup60's C-terminus allows Nup60 to bind meiotic chromosomes and promotes sporulation without Nup2. In contrast, binding of the meiotic-autonomous region to meiotic chromosomes is completely dependent on Nup60. Our findings uncover an inhibitory function for the Nup60 C-terminus and suggest that Nup60 mediates recruitment of meiotic chromosomes to the nuclear envelope, while Nup2 plays a secondary role counteracting the inhibitory function in Nup60's C-terminus.
Collapse
Affiliation(s)
- Kelly Komachi
- Department of Molecular and Cellular Biology, University of California, Davis, Davis, CA 95616, USA
| | - Sean M Burgess
- Department of Molecular and Cellular Biology, University of California, Davis, Davis, CA 95616, USA,Corresponding author: Department of Molecular and Cellular Biology, University of California, Davis, Davis, CA 95616, USA.
| |
Collapse
|