1
|
Eghtesadi N, Olaifa K, Pham TT, Capriati V, Ajunwa OM, Marsili E. Osmoregulation by choline-based deep eutectic solvent induces electroactivity in Bacillus subtilis biofilms. Enzyme Microb Technol 2024; 180:110485. [PMID: 39059288 DOI: 10.1016/j.enzmictec.2024.110485] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2023] [Revised: 06/23/2024] [Accepted: 07/15/2024] [Indexed: 07/28/2024]
Abstract
Gram-positive Bacillus subtilis is a model organism for the biotechnology industry and has recently been characterized as weakly electroactive in both planktonic cultures and biofilms. Increasing the extracellular electron transfer (EET) rate in B. subtilis biofilms will help to develop an efficient microbial electrochemical technology (MET) and improve the bioproduction of high-value metabolites under electrofermentative conditions. In our previous work, we have shown that the addition of compatible solute precursors such as choline chloride (ChCl) to the growth medium formulation increases current output and biofilm formation in B. subtilis. In this work, we utilized a low-carbon tryptone yeast extract medium with added salts to further expose B. subtilis to salt stress and observe the osmoregulatory and/or nutritional effects of a D-sorbitol/choline chloride (ChCl) (1:1 mol mol-1) deep eutectic solvents (DESs) on the electroactivity of the formed biofilm. The results show that ChCl and D-sorbitol alleviate the osmotic stress induced by the addition of NaH2PO4 and KH2PO4 salts and boost biofilm production. This is probably due to the osmoprotective effect of ChCl, a precursor of the osmoprotectant glycine betaine, and the induction of electroactive exopolymeric substances within the B. subtilis biofilm. Since high ionic strength media are commonly used in microbial biotechnology, the combination of ChCl-containing DESs and salt stress could enhance biofilm-based electrofermentation processes that bring significant benefits for biotechnological applications.
Collapse
Affiliation(s)
- Neda Eghtesadi
- Department of Chemical and Materials Engineering, School of Engineering and Digital, Sciences, Nazarbayev University, 53 Kabanbay Batyr Avenue, Astana 01000, Kazakhstan
| | - Kayode Olaifa
- Department of Chemical and Materials Engineering, School of Engineering and Digital, Sciences, Nazarbayev University, 53 Kabanbay Batyr Avenue, Astana 01000, Kazakhstan
| | - Tri T Pham
- Department of Biology, School of Sciences and Humanities, Nazarbayev University, 53 Kabanbay Batyr Avenue, Astana 01000, Kazakhstan
| | - Vito Capriati
- Dipartimento di Farmacia - Scienze del Farmaco, Consorzio CINMPIS, Università degli Studi di Bari Aldo Moro, Bari 70125, Italy
| | - Obinna M Ajunwa
- Interdisciplinary Nanoscience Center (iNANO), Faculty of Natural Sciences, Aarhus University, Aarhus, Denmark.
| | - Enrico Marsili
- Nottingham Ningbo China Beacons of Excellence Research and Innovation Institute, University of Nottingham Ningbo China, Ningbo, China.
| |
Collapse
|
2
|
Hariri Akbari F, Song Z, Turk M, Gunde-Cimerman N, Gostinčar C. Experimental evolution of extremotolerant and extremophilic fungi under osmotic stress. IUBMB Life 2024; 76:617-631. [PMID: 38647201 DOI: 10.1002/iub.2825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2023] [Accepted: 03/15/2024] [Indexed: 04/25/2024]
Abstract
Experimental evolution was carried out to investigate the adaptive responses of extremotolerant fungi to a stressful environment. For 12 cultivation cycles, the halotolerant black yeasts Aureobasidium pullulans and Aureobasidium subglaciale were grown at high NaCl or glycerol concentrations, and the halophilic basidiomycete Wallemia ichthyophaga was grown close to its lower NaCl growth limit. All evolved Aureobasidium spp. accelerated their growth at low water activity. Whole genomes of the evolved strains were sequenced. No aneuploidies were detected in any of the genomes, contrary to previous studies on experimental evolution at high salinity with other species. However, several hundred single-nucleotide polymorphisms were identified compared with the genomes of the progenitor strains. Two functional groups of genes were overrepresented among the genes presumably affected by single-nucleotide polymorphisms: voltage-gated potassium channels in A. pullulans at high NaCl concentration, and hydrophobins in W. ichthyophaga at low NaCl concentration. Both groups of genes were previously associated with adaptation to high salinity. Finally, most evolved Aureobasidium spp. strains were found to have increased intracellular and decreased extracellular glycerol concentrations at high salinity, suggesting that the strains have optimised their management of glycerol, their most important compatible solute. Experimental evolution therefore not only confirmed the role of potassium transport, glycerol management, and cell wall in survival at low water activity, but also demonstrated that fungi from extreme environments can further improve their growth rates under constant extreme conditions in a relatively short time and without large scale genomic rearrangements.
Collapse
Affiliation(s)
- Farhad Hariri Akbari
- Biotechnical Faculty, Department of Biology, University of Ljubljana, Ljubljana, Slovenia
| | - Zewei Song
- BGI-Shenzhen, Beishan Industrial Zone, Shenzhen, China
- China National GeneBank, BGI-Shenzhen, Shenzhen, China
| | - Martina Turk
- Biotechnical Faculty, Department of Biology, University of Ljubljana, Ljubljana, Slovenia
| | - Nina Gunde-Cimerman
- Biotechnical Faculty, Department of Biology, University of Ljubljana, Ljubljana, Slovenia
| | - Cene Gostinčar
- Biotechnical Faculty, Department of Biology, University of Ljubljana, Ljubljana, Slovenia
| |
Collapse
|
3
|
Kim YY, Kim JC, Kim S, Yang JE, Kim HM, Park HW. Heterotypic stress-induced adaptive evolution enhances freeze-drying tolerance and storage stability of Leuconostoc mesenteroides WiKim33. Food Res Int 2024; 175:113731. [PMID: 38128991 DOI: 10.1016/j.foodres.2023.113731] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 11/15/2023] [Accepted: 11/22/2023] [Indexed: 12/23/2023]
Abstract
Lactic acid bacteria (LAB) are currently being investigated for their potential use as probiotics and starter cultures. Researchers have developed powdering processes for the commercialization of LAB. Previous studies have focused on identifying innovative cryoprotective agents and freeze-drying (FD) techniques to enhance the stability of LAB. In this study, adaptive laboratory evolution (ALE) was employed to develop a strain with high FD tolerance and enhanced storage stability. Leuconostoc mesenteroids WiKim33 was subjected to heterotypic shock (heat and osmosis shock) to induce the desired phenotype and genotype. An FD-tolerant enhanced Leu. mesenteroides WiKim33 strain (ALE50) was obtained, which harbored a modified fatty acid composition and cell envelope characteristics. Specifically, ALE50 showed a lower unsaturated fatty acid (UFA)/saturated fatty acid (SFA) ratio and a higher cyclic fatty acid (CFA) composition. Moreover, the exopolysaccharide (EPS) thickness increased significantly by 331% compared to that of the wild type (WT). FD tolerance, which was evaluated using viability testing after FD, was enhanced by 33.4%. Overall, we demonstrated the feasibility of ALE to achieve desirable characteristics and provided insights into the mechanisms underlying increased FD tolerance.
Collapse
Affiliation(s)
- Yeong Yeol Kim
- Technology Innovation Research Division, World Institute of Kimchi, Gwangju 61755, Republic of Korea; Department of Integrative Food, Bioscience and Biotechnology, Chonnam National University, Gwangju 61186, Republic of Korea
| | - Jong-Cheol Kim
- Technology Innovation Research Division, World Institute of Kimchi, Gwangju 61755, Republic of Korea
| | - Seulbi Kim
- Technology Innovation Research Division, World Institute of Kimchi, Gwangju 61755, Republic of Korea; Division of Applied Bioscience & Biotechnology, Chonnam National University, Gwangju 61186, Republic of Korea
| | - Jung Eun Yang
- Technology Innovation Research Division, World Institute of Kimchi, Gwangju 61755, Republic of Korea
| | - Ho Myeong Kim
- Technology Innovation Research Division, World Institute of Kimchi, Gwangju 61755, Republic of Korea.
| | - Hae Woong Park
- Technology Innovation Research Division, World Institute of Kimchi, Gwangju 61755, Republic of Korea.
| |
Collapse
|
4
|
Kumar D, Gayen A, Chandra M. Hypo-osmotic Stress Increases Permeability of Individual Barriers in Escherichia coli Cell Envelope, Enabling Rapid Drug Transport. ACS Infect Dis 2023; 9:2471-2481. [PMID: 37950691 DOI: 10.1021/acsinfecdis.3c00326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2023]
Abstract
Survival of foodborne Gram-negative bacteria during osmotic stress often leads to multidrug resistance development. However, despite the concern, how osmoadaptation alters drug penetration across the Gram-negative bacterial cell envelope has remained inconclusive for years. Here, we have investigated drug permeation and accumulation inside hypo-osmotically shocked Escherichia coli. Three different quaternary ammonium compounds (QACs) are used as cationic amine-containing drug representatives; they also serve as envelope permeability indicators in different assays. Propidium iodide fluorescence reveals cytoplasmic accumulation and overall envelope permeability, while crystal violet sorption and second harmonic generation (SHG) spectroscopy reveal periplasmic accumulation and outer membrane permeability. Malachite green sorption and SHG results reveal transport across both the outer and inner membranes and accumulation in the periplasm as well as cytoplasm. The findings are found to be complementary to one another, collectively revealing enhanced permeabilities of both membranes and the periplasmic space in response to hypo-osmotic stress in E. coli. Enhanced permeability leads to faster QACs transport and higher accumulation in subcellular compartments, whereas transport and accumulation both are negligible under isosmotic conditions. The QACs' transport rates are found to be highly influenced by the osmolytes used, where phosphate ion emerges as a key facilitator of transport across the periplasm into the cytoplasm. E. coli is found viable, with morphology unchanged under extreme hypo-osmotic stress; i.e., it adapts to the situation. The outcome shows that the hypo-osmotic shock to E. coli, specifically using phosphate as an osmolyte, can be beneficial for drug delivery.
Collapse
Affiliation(s)
- Deepak Kumar
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur-208016, Uttar Pradesh, India
| | - Anindita Gayen
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur-208016, Uttar Pradesh, India
| | - Manabendra Chandra
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur-208016, Uttar Pradesh, India
- Center of Excellence: Tropical and Infectious Diseases, Gangwal School of Medical Sciences and Technology, Indian Institute of Technology Kanpur, Kanpur-208016, Uttar Pradesh, India
| |
Collapse
|
5
|
Kanaparthi D, Lampe M, Krohn JH, Zhu B, Klingl A, Lueders T. The reproduction of gram-negative protoplasts and the influence of environmental conditions on this process. iScience 2023; 26:108149. [PMID: 37942012 PMCID: PMC10628739 DOI: 10.1016/j.isci.2023.108149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 01/31/2023] [Accepted: 10/02/2023] [Indexed: 11/10/2023] Open
Abstract
Bacterial protoplasts are known to reproduce independently of canonical molecular biological processes. Although their reproduction is thought to be influenced by environmental conditions, the growth of protoplasts in their natural habitat has never been empirically studied. Here, we studied the life cycle of protoplasts in their native environment. Contrary to the previous perception that protoplasts reproduce in an erratic manner, cells in our study reproduced in a defined sequence of steps, always leading to viable daughter cells. Their reproduction can be explained by an interplay between intracellular metabolism, the physicochemical properties of cell constituents, and the nature of cations in the growth media. The efficiency of reproduction is determined by the environmental conditions. Under favorable environmental conditions, protoplasts reproduce with nearly similar efficiency to cells that possess a cell wall. In short, here we demonstrate the simplest method of cellular reproduction and the influence of environmental conditions on this process.
Collapse
Affiliation(s)
- Dheeraj Kanaparthi
- Max-Planck Institute for Biochemistry, Munich, Germany
- Chair of Ecological Microbiology, BayCeer, University of Bayreuth, Bayreuth, Germany
- Excellence Cluster ORIGINS, Garching, Germany
| | - Marko Lampe
- Advanced Light Microscopy Facility, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Jan-Hagen Krohn
- Max-Planck Institute for Biochemistry, Munich, Germany
- Excellence Cluster ORIGINS, Garching, Germany
| | - Baoli Zhu
- Chair of Ecological Microbiology, BayCeer, University of Bayreuth, Bayreuth, Germany
- Key Laboratory of Agro-ecological Processes in Subtropical Regions, CAS, Changsha, China
| | - Andreas Klingl
- Department of Biology, LMU, Planegg-Martinsried, Germany
| | - Tillmann Lueders
- Chair of Ecological Microbiology, BayCeer, University of Bayreuth, Bayreuth, Germany
| |
Collapse
|
6
|
Rudenko O, Baseggio L, McGuigan F, Barnes AC. Transforming the untransformable with knockout minicircles: High-efficiency transformation and vector-free allelic exchange knockout in the fish pathogen Photobacterium damselae. Microbiologyopen 2023; 12:e1374. [PMID: 37642481 PMCID: PMC10441182 DOI: 10.1002/mbo3.1374] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Revised: 07/27/2023] [Accepted: 08/03/2023] [Indexed: 08/31/2023] Open
Abstract
Gene inactivation studies are critical in pathogenic bacteria, where insights into species biology can guide the development of vaccines and treatments. Allelic exchange via homologous recombination is a generic method of targeted gene editing in bacteria. However, generally applicable protocols are lacking, and suboptimal approaches are often used for nonstandard but epidemiologically important species. Photobacterium damselae subsp. piscicida (Pdp) is a primary pathogen of fish in aquaculture and has been considered hard to transform since the mid-1990s. Consequently, conjugative transfer of RK2/RP4 suicide vectors from Escherichia coli S17-1/SM10 donor strains, a system prone to off-target mutagenesis, was used to deliver the allelic exchange DNA in previous studies. Here we have achieved efficient electrotransformation in Pdp using a salt-free highly concentrated sucrose solution, which performs as a hypertonic wash buffer, cryoprotectant, and electroporation buffer. High-efficiency transformation has enabled vector-free mutagenesis for which we have employed circular minimalistic constructs (knockout minicircles) containing only allelic exchange essentials that were generated by Gibson assembly. Preparation of competent cells using sucrose and electroporation/integration of minicircles had virtually no detectable off-target promutagenic effect. In contrast, a downstream sacB selection apparently induced several large deletions via mobilization of transposable elements. Electroporation of minicircles into sucrose-treated cells is a versatile broadly applicable approach that may facilitate allelic exchange in a wide range of microbial species. The method permitted inactivation of a primary virulence factor unique to Pdp, apoptogenic toxin AIP56, demonstrating the efficacy of minicircles for difficult KO targets located on the high copy number of small plasmids.
Collapse
Affiliation(s)
- Oleksandra Rudenko
- School of Biological Sciences and Centre for Marine ScienceThe University of QueenslandBrisbaneQueenslandAustralia
| | - Laura Baseggio
- School of Biological Sciences and Centre for Marine ScienceThe University of QueenslandBrisbaneQueenslandAustralia
| | - Fynn McGuigan
- School of Chemistry and Molecular BiosciencesThe University of QueenslandBrisbaneQueenslandAustralia
| | - Andrew C. Barnes
- School of Biological Sciences and Centre for Marine ScienceThe University of QueenslandBrisbaneQueenslandAustralia
| |
Collapse
|
7
|
Piscon B, Pia Esposito E, Fichtman B, Samburski G, Efremushkin L, Amselem S, Harel A, Rahav G, Zarrilli R, Gal-Mor O. The Effect of Outer Space and Other Environmental Cues on Bacterial Conjugation. Microbiol Spectr 2023; 11:e0368822. [PMID: 36995224 PMCID: PMC10269834 DOI: 10.1128/spectrum.03688-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Accepted: 03/11/2023] [Indexed: 03/31/2023] Open
Abstract
Bacterial conjugation is one of the most abundant horizontal gene transfer (HGT) mechanisms, playing a fundamental role in prokaryote evolution. A better understanding of bacterial conjugation and its cross talk with the environment is needed for a more complete understanding of HGT mechanisms and to fight the dissemination of malicious genes between bacteria. Here, we studied the effect of outer space, microgravity, and additional key environmental cues on transfer (tra) gene expression and conjugation efficiency, using the under studied broad-host range plasmid pN3, as a model. High resolution scanning electron microscopy revealed the morphology of the pN3 conjugative pili and mating pair formation during conjugation. Using a nanosatellite carrying a miniaturized lab, we studied pN3 conjugation in outer space, and used qRT-PCR, Western blotting and mating assays to determine the effect of ground physicochemical parameters on tra gene expression and conjugation. We showed for the first time that bacterial conjugation can occur in outer space and on the ground, under microgravity-simulated conditions. Furthermore, we demonstrated that microgravity, liquid media, elevated temperature, nutrient depletion, high osmolarity and low oxygen significantly reduce pN3 conjugation. Interestingly, under some of these conditions we observed an inverse correlation between tra gene transcription and conjugation frequency and found that induction of at least traK and traL can negatively affect pN3 conjugation frequency in a dose-dependent manner. Collectively, these results uncover pN3 regulation by various environmental cues and highlight the diversity of conjugation systems and the different ways in which they may be regulated in response to abiotic signals. IMPORTANCE Bacterial conjugation is a highly ubiquitous and promiscuous process, by which a donor bacterium transfers a large portion of genetic material to a recipient cell. This mechanism of horizontal gene transfer plays an important role in bacterial evolution and in the ability of bacteria to acquire resistance to antimicrobial drugs and disinfectants. Bacterial conjugation is a complex and energy-consuming process, that is tightly regulated and largely affected by various environmental signals sensed by the bacterial cell. Comprehensive knowledge about bacterial conjugation and the ways it is affected by environmental cues is required to better understand bacterial ecology and evolution and to find new effective ways to counteract the threating dissemination of antibiotic resistance genes between bacterial populations. Moreover, characterizing this process under stress or suboptimal growth conditions such as elevated temperatures, high salinity or in the outer space, may provide insights relevant to future habitat environmental conditions.
Collapse
Affiliation(s)
- Bar Piscon
- The Infectious Diseases Research Laboratory, Sheba Medical Center, Tel-Hashomer, Israel
- Department of Clinical Microbiology and Immunology, Tel Aviv University, Tel Aviv, Israel
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Eliana Pia Esposito
- Department of Public Health, University of Naples Federico II, Naples, Italy
| | - Boris Fichtman
- Azrieli Faculty of Medicine, Bar-Ilan University, Safed, Israel
| | - Guy Samburski
- SpacePharma R&D Israel LTD., Herzliya Pituach, Israel & SpacePharma SA, Courgenay, Switzerland
| | - Lihi Efremushkin
- SpacePharma R&D Israel LTD., Herzliya Pituach, Israel & SpacePharma SA, Courgenay, Switzerland
| | - Shimon Amselem
- SpacePharma R&D Israel LTD., Herzliya Pituach, Israel & SpacePharma SA, Courgenay, Switzerland
| | - Amnon Harel
- Azrieli Faculty of Medicine, Bar-Ilan University, Safed, Israel
| | - Galia Rahav
- The Infectious Diseases Research Laboratory, Sheba Medical Center, Tel-Hashomer, Israel
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Raffaele Zarrilli
- Department of Public Health, University of Naples Federico II, Naples, Italy
| | - Ohad Gal-Mor
- The Infectious Diseases Research Laboratory, Sheba Medical Center, Tel-Hashomer, Israel
- Department of Clinical Microbiology and Immunology, Tel Aviv University, Tel Aviv, Israel
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| |
Collapse
|
8
|
Devarajan AK, Truu M, Gopalasubramaniam SK, Muthukrishanan G, Truu J. Application of data integration for rice bacterial strain selection by combining their osmotic stress response and plant growth-promoting traits. Front Microbiol 2022; 13:1058772. [PMID: 36590400 PMCID: PMC9797599 DOI: 10.3389/fmicb.2022.1058772] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Accepted: 11/29/2022] [Indexed: 12/23/2022] Open
Abstract
Agricultural application of plant-beneficial bacteria to improve crop yield and alleviate the stress caused by environmental conditions, pests, and pathogens is gaining popularity. However, before using these bacterial strains in plant experiments, their environmental stress responses and plant health improvement potential should be examined. In this study, we explored the applicability of three unsupervised machine learning-based data integration methods, including principal component analysis (PCA) of concatenated data, multiple co-inertia analysis (MCIA), and multiple kernel learning (MKL), to select osmotic stress-tolerant plant growth-promoting (PGP) bacterial strains isolated from the rice phyllosphere. The studied datasets consisted of direct and indirect PGP activity measurements and osmotic stress responses of eight bacterial strains previously isolated from the phyllosphere of drought-tolerant rice cultivar. The production of phytohormones, such as indole-acetic acid (IAA), gibberellic acid (GA), abscisic acid (ABA), and cytokinin, were used as direct PGP traits, whereas the production of hydrogen cyanide and siderophore and antagonistic activity against the foliar pathogens Pyricularia oryzae and Helminthosporium oryzae were evaluated as measures of indirect PGP activity. The strains were subjected to a range of osmotic stress levels by adding PEG 6000 (0, 11, 21, and 32.6%) to their growth medium. The results of the osmotic stress response experiments showed that all bacterial strains accumulated endogenous proline and glycine betaine (GB) and exhibited an increase in growth, when osmotic stress levels were increased to a specific degree, while the production of IAA and GA considerably decreased. The three applied data integration methods did not provide a similar grouping of the strains. Especially deviant was the ordination of microbial strains based on the PCA of concatenated data. However, all three data integration methods indicated that the strains Bacillus altitudinis PB46 and B. megaterium PB50 shared high similarity in PGP traits and osmotic stress response. Overall, our results indicate that data integration methods complement the single-table data analysis approach and improve the selection process for PGP microbial strains.
Collapse
Affiliation(s)
- Arun Kumar Devarajan
- Institute of Molecular and Cell Biology, University of Tartu, Tartu, Estonia,*Correspondence: Arun Kumar Devarajan,
| | - Marika Truu
- Institute of Molecular and Cell Biology, University of Tartu, Tartu, Estonia
| | - Sabarinathan Kuttalingam Gopalasubramaniam
- Department of Plant Pathology, Agricultural College and Research Institute, Tamil Nadu Agricultural University, Killikulam, Tuticorin, India,Sabarinathan Kuttalingam Gopalasubramaniam,
| | - Gomathy Muthukrishanan
- Department of Soil Science and Agricultural Chemistry, Agricultural College and Research Institute, Tamil Nadu Agricultural University, Killikulam, Tuticorin, India
| | - Jaak Truu
- Institute of Molecular and Cell Biology, University of Tartu, Tartu, Estonia
| |
Collapse
|
9
|
Exploring species-level infant gut bacterial biodiversity by meta-analysis and formulation of an optimized cultivation medium. NPJ Biofilms Microbiomes 2022; 8:88. [PMID: 36316342 PMCID: PMC9622858 DOI: 10.1038/s41522-022-00349-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Accepted: 10/11/2022] [Indexed: 11/06/2022] Open
Abstract
In vitro gut cultivation models provide host-uncoupled, fast, and cost-efficient solutions to investigate the effects of intrinsic and extrinsic factors impacting on both composition and functionality of the intestinal microbial ecosystem. However, to ensure the maintenance and survival of gut microbial players and preserve their functions, these systems require close monitoring of several variables, including oxygen concentration, pH, and temperature, as well as the use of a culture medium satisfying the microbial nutritional requirements. In this context, in order to identify the macro- and micro-nutrients necessary for in vitro cultivation of the infant gut microbiota, a meta-analysis based on 1669 publicly available shotgun metagenomic samples corresponding to fecal samples of healthy, full-term infants aged from a few days to three years was performed to define the predominant species characterizing the “infant-like” gut microbial ecosystem. A subsequent comparison of growth performances was made using infant fecal samples that contained the most abundant bacterial taxa of the infant gut microbiota, when cultivated on 18 different culture media. This growth analysis was performed by means of flow cytometry-based bacterial cell enumeration and shallow shotgun sequencing, which allowed the formulation of an optimized growth medium, i.e., Infant Gut Super Medium (IGSM), which maintains and sustains the infant gut microbial biodiversity under in vitro growth conditions. Furthermore, this formulation was used to evaluate the in vitro effect of two drugs commonly used in pediatrics, i.e., acetaminophen and simethicone, on the taxonomic composition of the infant gut microbiota.
Collapse
|
10
|
Eghtesadi N, Olaifa K, Perna FM, Capriati V, Trotta M, Ajunwa O, Marsili E. Electroactivity of weak electricigen Bacillus subtilis biofilms in solution containing deep eutectic solvent components. Bioelectrochemistry 2022; 147:108207. [PMID: 35839687 DOI: 10.1016/j.bioelechem.2022.108207] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Revised: 07/07/2022] [Accepted: 07/07/2022] [Indexed: 11/02/2022]
Abstract
Bacillus subtilis is a Gram-positive, spore-forming bacterium with a versatile and adaptable metabolism, which makes it a viable cell factory for microbial production. Electroactivity has recently been identified as a cellular characteristic linked with the metabolic activity of B. subtilis. The enhancement of B. subtilis electroactivity can positively enhance bioproduction of high-added value metabolites under electrofermentative conditions. Here, we explored the use of deep eutectic solvents (DESs) and DES components as biocompatible nutrient additives for enhancing electroactivity of B. subtilis. The strongest electroactivity was obtained in an aqueous choline chloride: glycerol (1:2 mol mol-1) eutectic mixture. At low concentration (50-500 mM), this mixture induced a pseudo-diauxic increase in planktonic growth and increased biofilm formation, likely due to a nutritional and osmoprotectant effect. Similarities in electroactivity enhancements of choline chloride-based eutectic mixtures and quinone redox metabolism in B. subtilis were detected using high performance liquid chromatography and differential pulse voltammetry. Results show that choline chloride-based aqueous eutectic mixtures can enhance biomass and productivity in biofilm-based electrofermentation. However, the specific mechanism needs to be fully elucidated.
Collapse
Affiliation(s)
- Neda Eghtesadi
- Biofilm Laboratory, Nazarbayev University, 53 Kabanbay Batyr Avenue, Nur-Sultan 01000, Kazakhstan
| | - Kayode Olaifa
- Biofilm Laboratory, Nazarbayev University, 53 Kabanbay Batyr Avenue, Nur-Sultan 01000, Kazakhstan
| | - Filippo Maria Perna
- Dipartimento di Farmacia - Scienze del Farmaco, Università degli Studi di Bari "Aldo Moro," via E. Orabona 4, I-70125 Bari, Italy
| | - Vito Capriati
- Dipartimento di Farmacia - Scienze del Farmaco, Università degli Studi di Bari "Aldo Moro," via E. Orabona 4, I-70125 Bari, Italy
| | - Massimo Trotta
- Istituto per i Processi Chimico Fisici, CNR, via E. Orabona 4, I-70125 Bari, Italy
| | - Obinna Ajunwa
- Biofilm Laboratory, Nazarbayev University, 53 Kabanbay Batyr Avenue, Nur-Sultan 01000, Kazakhstan; Department of Microbiology, Modibbo Adama University, Yola, Nigeria.
| | - Enrico Marsili
- Biofilm Laboratory, Nazarbayev University, 53 Kabanbay Batyr Avenue, Nur-Sultan 01000, Kazakhstan.
| |
Collapse
|
11
|
Ho PY, Good BH, Huang KC. Competition for fluctuating resources reproduces statistics of species abundance over time across wide-ranging microbiotas. eLife 2022; 11:75168. [PMID: 35404785 PMCID: PMC9000955 DOI: 10.7554/elife.75168] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Accepted: 03/24/2022] [Indexed: 12/20/2022] Open
Abstract
Across diverse microbiotas, species abundances vary in time with distinctive statistical behaviors that appear to generalize across hosts, but the origins and implications of these patterns remain unclear. Here, we show that many of these macroecological patterns can be quantitatively recapitulated by a simple class of consumer-resource models, in which the metabolic capabilities of different species are randomly drawn from a common statistical distribution. Our model parametrizes the consumer-resource properties of a community using only a small number of global parameters, including the total number of resources, typical resource fluctuations over time, and the average overlap in resource-consumption profiles across species. We show that variation in these macroscopic parameters strongly affects the time series statistics generated by the model, and we identify specific sets of global parameters that can recapitulate macroecological patterns across wide-ranging microbiotas, including the human gut, saliva, and vagina, as well as mouse gut and rice, without needing to specify microscopic details of resource consumption. These findings suggest that resource competition may be a dominant driver of community dynamics. Our work unifies numerous time series patterns under a simple model, and provides an accessible framework to infer macroscopic parameters of effective resource competition from longitudinal studies of microbial communities.
Collapse
Affiliation(s)
- Po-Yi Ho
- Department of Bioengineering, Stanford University, Stanford, United States
| | - Benjamin H Good
- Department of Applied Physics, Stanford University, Stanford, United States.,Chan Zuckerberg Biohub, San Francisco, United States
| | - Kerwyn Casey Huang
- Department of Bioengineering, Stanford University, Stanford, United States.,Chan Zuckerberg Biohub, San Francisco, United States.,Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, United States
| |
Collapse
|
12
|
Seven Years at High Salinity-Experimental Evolution of the Extremely Halotolerant Black Yeast Hortaea werneckii. J Fungi (Basel) 2021; 7:jof7090723. [PMID: 34575761 PMCID: PMC8468603 DOI: 10.3390/jof7090723] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 08/30/2021] [Accepted: 09/02/2021] [Indexed: 01/26/2023] Open
Abstract
The experimental evolution of microorganisms exposed to extreme conditions can provide insight into cellular adaptation to stress. Typically, stress-sensitive species are exposed to stress over many generations and then examined for improvements in their stress tolerance. In contrast, when starting with an already stress-tolerant progenitor there may be less room for further improvement, it may still be able to tweak its cellular machinery to increase extremotolerance, perhaps at the cost of poorer performance under non-extreme conditions. To investigate these possibilities, a strain of extremely halotolerant black yeast Hortaea werneckii was grown for over seven years through at least 800 generations in a medium containing 4.3 M NaCl. Although this salinity is well above the optimum (0.8–1.7 M) for the species, the growth rate of the evolved H. werneckii did not change in the absence of salt or at high concentrations of NaCl, KCl, sorbitol, or glycerol. Other phenotypic traits did change during the course of the experimental evolution, including fewer multicellular chains in the evolved strains, significantly narrower cells, increased resistance to caspofungin, and altered melanisation. Whole-genome sequencing revealed the occurrence of multiple aneuploidies during the experimental evolution of the otherwise diploid H. werneckii. A significant overrepresentation of several gene groups was observed in aneuploid regions. Taken together, these changes suggest that long-term growth at extreme salinity led to alterations in cell wall and morphology, signalling pathways, and the pentose phosphate cycle. Although there is currently limited evidence for the adaptive value of these changes, they offer promising starting points for future studies of fungal halotolerance.
Collapse
|
13
|
Otaru N, Ye K, Mujezinovic D, Berchtold L, Constancias F, Cornejo FA, Krzystek A, de Wouters T, Braegger C, Lacroix C, Pugin B. GABA Production by Human Intestinal Bacteroides spp.: Prevalence, Regulation, and Role in Acid Stress Tolerance. Front Microbiol 2021; 12:656895. [PMID: 33936013 PMCID: PMC8082179 DOI: 10.3389/fmicb.2021.656895] [Citation(s) in RCA: 88] [Impact Index Per Article: 29.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Accepted: 03/24/2021] [Indexed: 12/11/2022] Open
Abstract
The high neuroactive potential of metabolites produced by gut microbes has gained traction over the last few years, with metagenomic-based studies suggesting an important role of microbiota-derived γ-aminobutyric acid (GABA) in modulating mental health. Emerging evidence has revealed the presence of the glutamate decarboxylase (GAD)-encoding gene, a key enzyme to produce GABA, in the prominent human intestinal genus Bacteroides. Here, we investigated GABA production by Bacteroides in culture and metabolic assays combined with comparative genomics and phylogenetics. A total of 961 Bacteroides genomes were analyzed in silico and 17 metabolically and genetically diverse human intestinal isolates representing 11 species were screened in vitro. Using the model organism Bacteroides thetaiotaomicron DSM 2079, we determined GABA production kinetics, its impact on milieu pH, and we assessed its role in mitigating acid-induced cellular damage. We showed that the GAD-system consists of at least four highly conserved genes encoding a GAD, a glutaminase, a glutamate/GABA antiporter, and a potassium channel. We demonstrated a high prevalence of the GAD-system among Bacteroides with 90% of all Bacteroides genomes (96% in human gut isolates only) harboring all genes of the GAD-system and 16 intestinal Bacteroides strains producing GABA in vitro (ranging from 0.09 to 60.84 mM). We identified glutamate and glutamine as precursors of GABA production, showed that the production is regulated by pH, and that the GAD-system acts as a protective mechanism against acid stress in Bacteroides, mitigating cell death and preserving metabolic activity. Our data also indicate that the GAD-system might represent the only amino acid-dependent acid tolerance system in Bacteroides. Altogether, our results suggest an important contribution of Bacteroides in the regulation of the GABAergic system in the human gut.
Collapse
Affiliation(s)
- Nize Otaru
- Laboratory of Food Biotechnology, Department of Health Sciences and Technology, ETH Zürich, Zürich, Switzerland.,Nutrition Research Unit, University Children's Hospital Zürich, Zürich, Switzerland
| | - Kun Ye
- Laboratory of Food Biotechnology, Department of Health Sciences and Technology, ETH Zürich, Zürich, Switzerland
| | - Denisa Mujezinovic
- Laboratory of Food Biotechnology, Department of Health Sciences and Technology, ETH Zürich, Zürich, Switzerland
| | - Laura Berchtold
- Laboratory of Food Biotechnology, Department of Health Sciences and Technology, ETH Zürich, Zürich, Switzerland.,PharmaBiome AG, Zürich, Switzerland
| | - Florentin Constancias
- Laboratory of Food Biotechnology, Department of Health Sciences and Technology, ETH Zürich, Zürich, Switzerland
| | - Fabián A Cornejo
- Max Planck Unit for the Science of Pathogens, Berlin, Germany.,Laboratory of Molecular Microbiology, Faculty of Chemistry and Biology, University of Santiago, Santiago, Chile
| | - Adam Krzystek
- Laboratory of Human Nutrition, Department of Health Sciences and Technology, ETH Zürich, Zürich, Switzerland
| | | | - Christian Braegger
- Nutrition Research Unit, University Children's Hospital Zürich, Zürich, Switzerland
| | - Christophe Lacroix
- Laboratory of Food Biotechnology, Department of Health Sciences and Technology, ETH Zürich, Zürich, Switzerland
| | - Benoit Pugin
- Laboratory of Food Biotechnology, Department of Health Sciences and Technology, ETH Zürich, Zürich, Switzerland
| |
Collapse
|