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Sele V, Ali A, Liland N, Lundebye AK, Tibon J, Araujo P, Sindre H, Nilsen H, Hagemann A, Belghit I. Characterization of nutrients and contaminants in fish sludge from Atlantic salmon (Salmo salar L.) production sites - A future resource. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 360:121103. [PMID: 38788405 DOI: 10.1016/j.jenvman.2024.121103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2024] [Revised: 04/29/2024] [Accepted: 05/05/2024] [Indexed: 05/26/2024]
Abstract
A total of 47 fish sludge samples from commercial land-based Atlantic salmon (Salmo salar) farms in Norway were assessed for their nutrient composition, presence of various legacy contaminants and a wide spectrum of contaminants of emerging concern, veterinary medicines as well as selected salmonid pathogenic bacteria and virus. The aim was to document the levels of desirable and undesirable components in fish sludge in relation to a potential future use of sludge as invertebrate feed. The samples had variable, but relatively high protein and fat contents, indicating a high load of undigested feed in some of the sludge samples. Fatty acid analysis showed the presence of essential omega-3 fatty acids. In terms of undesirable substances, 43% and 84% of the sludge samples contained levels of arsenic and cadmium, respectively, which exceeded the EU Maximum Levels established for complete animal feed. The concentrations of copper, zinc, iron and aluminum were highly variable in the sludge samples. The concentrations of dioxins, sum PCB6, and chlorinated pesticides were all below the Maximum Levels for animal feed. Of the 18 per- and polyfluoroalkyl substances (PFAS) only one compound (L-PFOS) was present at measurable levels. None of the samples had detectable levels of veterinary medicines, salmonid virus or bacteria. Performing a suspect and non-target screening of the sludge samples identified 18 compounds, including four pharmaceuticals, plastic-related products and the UV filter benzophenone, warranting further investigations. Overall, the results from this study show that fish sludge is a nutrient-rich resource; however, undesirable substances, originating from the feed or from treatment of sludge may be present.
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Affiliation(s)
- Veronika Sele
- Institute of Marine Research, P.O. Box 1870, Nordnes, Bergen, 5817, Norway.
| | - Aasim Ali
- Institute of Marine Research, P.O. Box 1870, Nordnes, Bergen, 5817, Norway
| | - Nina Liland
- Institute of Marine Research, P.O. Box 1870, Nordnes, Bergen, 5817, Norway
| | | | - Jojo Tibon
- Institute of Marine Research, P.O. Box 1870, Nordnes, Bergen, 5817, Norway
| | - Pedro Araujo
- Institute of Marine Research, P.O. Box 1870, Nordnes, Bergen, 5817, Norway
| | - Hilde Sindre
- Norwegian Veterinary Institute, P.O. 64, 1433, Ås, Norway
| | - Hanne Nilsen
- Norwegian Veterinary Institute, Thormølens Gate 53C, 5006, Bergen, Norway
| | - Andreas Hagemann
- SINTEF Ocean, Department of Fisheries and New Biomarine Industry, Brattørkaia 17C, 7010, Trondheim, Norway
| | - Ikram Belghit
- Institute of Marine Research, P.O. Box 1870, Nordnes, Bergen, 5817, Norway
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Pereira RFS, Ferreira MJ, Oliveira MC, Serra MC, de Carvalho CCCR. Isolation and Characterization of a Serratia rubidaea from a Shallow Water Hydrothermal Vent. Mar Drugs 2023; 21:599. [PMID: 38132920 PMCID: PMC10745058 DOI: 10.3390/md21120599] [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: 10/31/2023] [Revised: 11/17/2023] [Accepted: 11/17/2023] [Indexed: 12/23/2023] Open
Abstract
Microbial life present in the marine environment has to be able to adapt to rapidly changing and often extreme conditions. This makes these organisms a putative source of commercially interesting compounds since adaptation provides different biochemical routes from those found in their terrestrial counterparts. In this work, the goal was the identification of a marine bacterium isolated from a sample taken at a shallow water hydrothermal vent and of its red product. Genomic, lipidomic, and biochemical approaches were used simultaneously, and the bacterium was identified as Serratia rubidaea. A high-throughput screening strategy was used to assess the best physico-chemical conditions permitting both cell growth and production of the red product. The fatty acid composition of the microbial cells was studied to assess adaptation at the lipid level under stressful conditions, whilst several state-of-the-art techniques, such as DSC, FTIR, NMR, and Ultra-High Resolution Qq-Time-of-Flight mass spectrometry, were used to characterize the structure of the pigment. We hypothesize that the pigment, which could be produced by the cells up to 62 °C, is prodigiosin linked to an aliphatic compound that acts as an anchor to keep it close to the cells in the marine environment.
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Affiliation(s)
- Ricardo F. S. Pereira
- Department of Bioengineering, iBB—Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal;
- Associate Laboratory i4HB, Institute for Health and Bioeconomy, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
| | - Maria J. Ferreira
- Centro de Química Estrutural, Institute of Molecular Sciences, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal; (M.J.F.); (M.C.O.)
| | - M. Conceição Oliveira
- Centro de Química Estrutural, Institute of Molecular Sciences, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal; (M.J.F.); (M.C.O.)
| | - Maria C. Serra
- Área Departamental de Engenharia Química, Instituto Superior de Engenharia de Lisboa (ISEL), Rua Conselheiro Emídio Navarro, 1, 1959-007 Lisboa, Portugal;
| | - Carla C. C. R. de Carvalho
- Department of Bioengineering, iBB—Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal;
- Associate Laboratory i4HB, Institute for Health and Bioeconomy, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
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Liening-Ewert T, Tichy A, Mader C, Spergser J, Sodoma E, Ortner P, Kössler J, Khol JL. Management and housing factors associated with paratuberculosis-positive herds in small structured alpine cattle husbandry. Prev Vet Med 2023; 218:105999. [PMID: 37619426 DOI: 10.1016/j.prevetmed.2023.105999] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Revised: 07/28/2023] [Accepted: 08/10/2023] [Indexed: 08/26/2023]
Abstract
Paratuberculosis (Johne´s disease) is a world-wide cattle disease caused by Mycobacterium avium subsp. paratuberculosis (MAP), associated with substantial economic losses. Purchase of subclinically infected animals or contact with animals and equipment of infected farms are known risk factors for disease transmission among herds. The aim of the present study was to identify specific management factors in Austria that triggered a MAP-positive herd status and to evaluate known risk factors for the transmission in cattle in small structured alpine agricultural systems. The agriculture in the Austrian province of Tyrol is characterized by smallholder structures, including shared alpine pastures and traditional barn management techniques. The data from an extensive survey with 50 questions in 2013/2014 and the development of the MAP herd status of 5592 cattle farms by taking feces and blood samples were examined and statistically evaluated. MAP herd status was determined by combining the results of boot swab samples, manure samples, pooled and individual feces samples as well as serological antibody testing by ELISA. The statistical analysis (odds ratio; OR) showed that the use of milk replacers for calf feeding (p = 0.047, OR=0.472) and the use of straw as bedding material for cows (p = 0.032, OR=0.625) were associated with a decreased chance of being a MAP-positive herd. Further, housing cows in deep litter systems (p = 0.028, OR=2.232), the presence of slurry channels (p = 0.028, OR=1.411) and the use of solid manure in young cattle (p = 0.041, OR=1.744) were associated with an increased OR for being MAP-positive. Surprisingly, sharing of lowland pastures (p = 0.564, OR=1.080), alpine pastures (p = 0.419, OR=1.143) or farm equipment (p = 0.733, OR=0.963) and farm size (p = 0.425) had no significant influence on the MAP herd status. The identified differences compared with previously published results in respect of MAP spread in cattle might be attributed to the traditional agricultural structures, including small family-based farms and common pasture during summer in alpine regions. Results of this study contribute to the understanding of the spread of MAP in cattle farming in alpine regions.
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Affiliation(s)
| | - A Tichy
- Bioinformatics and Biostatistics Platform, Department for Biomedical Sciences, University of Veterinary Medicine Vienna, Austria
| | - C Mader
- Veterinary Health Service Tyrol, Austria
| | - J Spergser
- Institute of Microbiology Department for Pathobiology University of Veterinary Medicine Vienna, Austria
| | - E Sodoma
- Austrian Agency for Health and Food Safety Linz, Austria
| | - P Ortner
- Regional Veterinary Office Tyrol, Austria
| | - J Kössler
- Regional Veterinary Office Tyrol, Austria
| | - J L Khol
- University Clinic for Ruminants, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine Vienna, Austria.
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Noel D, Hallsworth JE, Gelhaye E, Darnet S, Sormani R, Morel-Rouhier M. Modes-of-action of antifungal compounds: Stressors and (target-site-specific) toxins, toxicants, or Toxin-stressors. Microb Biotechnol 2023. [PMID: 37191200 DOI: 10.1111/1751-7915.14242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 02/11/2023] [Accepted: 02/16/2023] [Indexed: 05/17/2023] Open
Abstract
Fungi and antifungal compounds are relevant to the United Nation's Sustainable Development Goals. However, the modes-of-action of antifungals-whether they are naturally occurring substances or anthropogenic fungicides-are often unknown or are misallocated in terms of their mechanistic category. Here, we consider the most effective approaches to identifying whether antifungal substances are cellular stressors, toxins/toxicants (that are target-site-specific), or have a hybrid mode-of-action as Toxin-stressors (that induce cellular stress yet are target-site-specific). This newly described 'toxin-stressor' category includes some photosensitisers that target the cell membrane and, once activated by light or ultraviolet radiation, cause oxidative damage. We provide a glossary of terms and a diagrammatic representation of diverse types of stressors, toxic substances, and Toxin-stressors, a classification that is pertinent to inhibitory substances not only for fungi but for all types of cellular life. A decision-tree approach can also be used to help differentiate toxic substances from cellular stressors (Curr Opin Biotechnol 2015 33: 228-259). For compounds that target specific sites in the cell, we evaluate the relative merits of using metabolite analyses, chemical genetics, chemoproteomics, transcriptomics, and the target-based drug-discovery approach (based on that used in pharmaceutical research), focusing on both ascomycete models and the less-studied basidiomycete fungi. Chemical genetic methods to elucidate modes-of-action currently have limited application for fungi where molecular tools are not yet available; we discuss ways to circumvent this bottleneck. We also discuss ecologically commonplace scenarios in which multiple substances act to limit the functionality of the fungal cell and a number of as-yet-unresolved questions about the modes-of-action of antifungal compounds pertaining to the Sustainable Development Goals.
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Affiliation(s)
| | - John E Hallsworth
- Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, Belfast, UK
| | - Eric Gelhaye
- Université de Lorraine, INRAE, IAM, Nancy, France
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Wang L, Huang G, Ma W, Jin G. Preparation and Application of Directed Vat Set Indigenous Freeze-Drying Lentilactobacillus hilgardii Q19 Starter in Winemaking. Foods 2023; 12:foods12051053. [PMID: 36900570 PMCID: PMC10000753 DOI: 10.3390/foods12051053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Revised: 02/23/2023] [Accepted: 02/24/2023] [Indexed: 03/06/2023] Open
Abstract
In order to prepare a better direct vat set for malolactic fermentation (MLF) in high ethanol and low pH wines, the high-ethanol- and low-temperature-tolerant strain Lentilactobacillus hilgardii Q19, which was isolated from the eastern foothill of the Helan Mountain wine region in China, was used to prepare a direct vat set by vacuum freeze-drying. A superior freeze-dried lyoprotectant was obtained to create the starting culture by selecting, combining, and optimizing numerous lyoprotectants with higher protection for Q19 by using a single-factor experiment and response surface approach. Finally, the Lentilactobacillus hilgardii Q19 direct vat set was inoculated in Cabernet Sauvignon wine to carry out MLF on a pilot scale, with commercial starter culture Oeno1 as control. The volatile compounds, biogenic amines, and ethyl carbamate content were analyzed. The results showed that a combination of 8.5 g/100 mL skimmed milk powder, 14.5 g/100 mL yeast extract powder, and 6.0 g/100 mL sodium hydrogen glutamate offered better protection; with this lyoprotectant, there were (4.36 ± 0.34) × 1011 CFU/g cells after freeze-drying, and it showed an excellent ability to degrade L-malic acid and could successfully finish MLF. In addition, in terms of aroma and wine safety, compared with Oeno1, the quantity and complexity of volatile compounds were increased after MLF, and biogenic amines and ethyl carbamate were produced less during MLF. We conclude that the Lentilactobacillus hilgardii Q19 direct vat set could be applied as a new MLF starter culture in high-ethanol wines.
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Affiliation(s)
- Ling Wang
- School of Agriculture, Ningxia University, Yinchuan 750021, China
| | - Gang Huang
- School of Agriculture, Ningxia University, Yinchuan 750021, China
| | - Wen Ma
- School of Food and Wine, Ningxia University, Yinchuan 750021, China
- Engineering Research Center of Ministry of Grape and Wine, Yinchuan 750021, China
| | - Gang Jin
- School of Food and Wine, Ningxia University, Yinchuan 750021, China
- Engineering Research Center of Ministry of Grape and Wine, Yinchuan 750021, China
- Correspondence:
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Liu Y, Xu Y, Cui X, Zhang B, Wang X, Qin X, Wang J, Li Y, Zhang W, Liu G, Chen T, Zhang G. Temporary Survival Increasing the Diversity of Culturable Heterotrophic Bacteria in the Newly Exposed Moraine at a Glacier Snout. BIOLOGY 2022; 11:biology11111555. [PMID: 36358257 PMCID: PMC9687651 DOI: 10.3390/biology11111555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2022] [Revised: 09/11/2022] [Accepted: 10/20/2022] [Indexed: 11/05/2022]
Abstract
Laohugou Glacier No. 12 is located on the northern slope of the western Qilian Mountains with a temperate continental wet climate and an extremely cold winter. Bacteria in a newly exposed moraine have to cope with various pressures owing to deglaciation at the glacier snout. However, limited information is available regarding the high diversity and temporary survival of culturable heterotrophic bacteria under various environmental stresses. To examine the tolerance of extremophiles against varying environmental conditions in a newly exposed moraine, we simulated environmental stress in bacterial cultures. The results showed that the isolated strains belonged to actinobacteria, Proteobacteria, Bacteroidetes, Deinococcus-Thermus, and Firmicutes. Actinobacteria was the most abundant phylum, followed by Proteobacteria, at both high and low temperatures. Pseudarthrobacter was the most abundant genus, accounting for 14.2% of the total isolates. Although several microorganisms grew at 10 °C, the proportion of microorganisms that grew at 25 °C was substantially higher. In particular, 50% of all bacterial isolates grew only at a high temperature (HT), whereas 21.4% of the isolates grew at a low temperature (LT), and 38.6% of the isolates grew at both HT and LT. In addition, many radiation-resistant extremophiles were identified, which adapted to both cold and oxidative conditions. The nearest neighbors of approximately >90% of bacteria belonged to a nonglacial environment, such as oil-contaminated soil, rocks, and black sand, instead of glacial niches. This study provides insights into the ecological traits, stress responses, and temporary survival of culturable heterotrophic bacteria in a newly exposed moraine with variable environmental conditions and the relationship of these communities with the non-glacial environment. This study may help to understand the evolution, competition, and selective growth of bacteria in the transition regions between glaciers and retreats in the context of glacier melting and retreat owing to global warming.
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Affiliation(s)
- Yang Liu
- State Key Laboratory of Cryospheric Sciences, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China
- University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing 100049, China
- Key Laboratory of Extreme Environmental Microbial Resources and Engineering, Lanzhou 730000, China
| | - Yeteng Xu
- State Key Laboratory of Cryospheric Sciences, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China
- University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing 100049, China
- Key Laboratory of Extreme Environmental Microbial Resources and Engineering, Lanzhou 730000, China
| | - Xiaowen Cui
- Key Laboratory of Extreme Environmental Microbial Resources and Engineering, Lanzhou 730000, China
- Key Laboratory of Desert and Desertification, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China
- College of Geography and Environment Science, Northwest Normal University, Lanzhou 730070, China
| | - Binglin Zhang
- State Key Laboratory of Cryospheric Sciences, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China
- University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing 100049, China
- Key Laboratory of Extreme Environmental Microbial Resources and Engineering, Lanzhou 730000, China
| | - Xinyue Wang
- University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing 100049, China
- Key Laboratory of Extreme Environmental Microbial Resources and Engineering, Lanzhou 730000, China
- Key Laboratory of Desert and Desertification, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China
| | - Xiang Qin
- State Key Laboratory of Cryospheric Sciences, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China
- Key Laboratory of Extreme Environmental Microbial Resources and Engineering, Lanzhou 730000, China
| | - Jinxiu Wang
- Key Laboratory of Extreme Environmental Microbial Resources and Engineering, Lanzhou 730000, China
- Key Laboratory of Desert and Desertification, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China
| | - Yanzhao Li
- State Key Laboratory of Cryospheric Sciences, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China
- University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing 100049, China
- Key Laboratory of Extreme Environmental Microbial Resources and Engineering, Lanzhou 730000, China
| | - Wei Zhang
- Key Laboratory of Extreme Environmental Microbial Resources and Engineering, Lanzhou 730000, China
- Key Laboratory of Desert and Desertification, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China
| | - Guangxiu Liu
- Key Laboratory of Extreme Environmental Microbial Resources and Engineering, Lanzhou 730000, China
- Key Laboratory of Desert and Desertification, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China
- School of Stomatology, Lanzhou University, Lanzhou 730000, China
| | - Tuo Chen
- State Key Laboratory of Cryospheric Sciences, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China
- Correspondence: (T.C.); (G.Z.)
| | - Gaosen Zhang
- Key Laboratory of Extreme Environmental Microbial Resources and Engineering, Lanzhou 730000, China
- Key Laboratory of Desert and Desertification, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China
- Correspondence: (T.C.); (G.Z.)
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Braga GÚL, Silva-Junior GJ, Brancini GTP, Hallsworth JE, Wainwright M. Photoantimicrobials in agriculture. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 2022; 235:112548. [PMID: 36067596 DOI: 10.1016/j.jphotobiol.2022.112548] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Revised: 07/30/2022] [Accepted: 08/16/2022] [Indexed: 06/15/2023]
Abstract
Classical approaches for controlling plant pathogens may be impaired by the development of pathogen resistance to chemical pesticides and by limited availability of effective antimicrobial agents. Recent increases in consumer awareness of and/or legislation regarding environmental and human health, and the urgent need to improve food security, are driving increased demand for safer antimicrobial strategies. Therefore, there is a need for a step change in the approaches used for controlling pre- and post-harvest diseases and foodborne human pathogens. The use of light-activated antimicrobial substances for the so-called antimicrobial photodynamic treatment is known to be effective not only in a clinical context, but also for use in agriculture to control plant-pathogenic fungi and bacteria, and to eliminate foodborne human pathogens from seeds, sprouted seeds, fruits, and vegetables. Here, we take a holistic approach to review and re-evaluate recent findings on: (i) the ecology of naturally-occurring photoantimicrobials, (ii) photodynamic processes including the light-activated antimicrobial activities of some plant metabolites, and (iii) fungus-induced photosensitization of plants. The inhibitory mechanisms of both natural and synthetic light-activated substances, known as photosensitizers, are discussed in the contexts of microbial stress biology and agricultural biotechnology. Their modes-of-antimicrobial action make them neither stressors nor toxins/toxicants (with specific modes of poisonous activity), but a hybrid/combination of both. We highlight the use of photoantimicrobials for the control of plant-pathogenic fungi and quantify their potential contribution to global food security.
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Affiliation(s)
- Gilberto Ú L Braga
- Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto 14040-903, Brazil.
| | | | - Guilherme T P Brancini
- Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto 14040-903, Brazil.
| | - John E Hallsworth
- Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, 19 Chlorine Gardens, Belfast BT9 5DL, Northern Ireland, United Kingdom.
| | - Mark Wainwright
- School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, Liverpool L3 3AF, United Kingdom.
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de Carvalho CCCR. Adaptation of Bacteria to Antineoplastic Agents Involves Persister Cells and Increases Resistance to Antibiotics. Bioengineering (Basel) 2022; 9:bioengineering9080355. [PMID: 36004880 PMCID: PMC9404991 DOI: 10.3390/bioengineering9080355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 07/25/2022] [Accepted: 07/27/2022] [Indexed: 11/16/2022] Open
Abstract
The increasing number of life-threatening infections observed in cancer patients has been ascribed to chemotherapy-induced neutropenia and to invasive medical procedures such as surgery and the application of catheters. In this study, it was questioned if the infections could also be favored by an increased resistance of bacteria due to the adaptation to antineoplastic agents used in chemotherapy. After exposure to several antineoplastic agents, it was observed that cells of Staphylococcus aureus, Mycobacterium vaccae, Pseudomonas aeruginosa, and Escherichia coli changed the fatty acid profile of their cellular membranes, produced exopolymeric substances, and formed aggregates that adhered to surfaces. Additionally, when exposed to high concentrations of these compounds, a persister sub-population could be identified. After adaptation to antineoplastic agents, the minimum inhibitory concentration (MIC) of several antibiotics increased considerably in the tested strains.
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Affiliation(s)
- Carla C. C. R. de Carvalho
- iBB-Institute for Bioengineering and Biosciences, Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisbon, Portugal; ; Tel.: +351-21-841-9594
- Associate Laboratory i4HB—Institute for Health and Bioeconomy, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisbon, Portugal
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Shifts in Bacterial Community Composition and Functional Traits at Different Time Periods Post-deglaciation of Gangotri Glacier, Himalaya. Curr Microbiol 2022; 79:91. [PMID: 35129698 DOI: 10.1007/s00284-022-02779-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Accepted: 01/20/2022] [Indexed: 11/03/2022]
Abstract
Climate change causes an unprecedented increase in glacial retreats. The melting ice exposes land for colonization and diversification of bacterial communities leading to soil development, changes in plant community composition, and ecosystem functioning. Although a few studies have focused on macro-level deglaciation impacts, little is known about such effects on the bacterial community succession. Here, we provide meta-barcoding-based insight into the ecological attributes of bacterial community across different retreating periods of the Gangotri glacier, western Himalaya. We selected three sites along a terminal moraine representing recent (~ 20 yrs), intermediate (~ 100 yrs), and late (~ 300 yrs) deglaciation periods. Results showed that the genus Mycobacterium belonging to phylum Actinobacteria dominated recently deglaciated land. Relative abundance of these pioneer bacterial taxa decreased by 20-50% in the later stages with the emergence of new and rising of the less abundant members of the phyla Proteobacteria, Firmicutes, Planctomycetes, Acidobacteria, Verrucomicrobia, Candidatus TM6, and Chloroflexi. The community in the recent stage was less rich and harbored competitive interactions, while the later stages experienced a surge in bacterial diversity with cooperative interactions. The shift in α-diversity and composition was strongly influenced by soil organic carbon, carbon to nitrogen ratio, and soil moisture content. The functional analyses revealed a progression from a metabolism focused to a functionally progressive community required for bacterial co-existence and succession in plant communities. Overall, the findings indicate that the bacterial communities inhabit, diversify, and develop specialized functions post-deglaciation leading to nutrient inputs to soil and vegetation development, which may provide feedback to climate change.
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Abstract
Water is the cellular milieu, drives all biochemistry within Earth's biosphere and facilitates microbe-mediated decay processes. Instead of reviewing these topics, the current article focuses on the activities of water as a preservative-its capacity to maintain the long-term integrity and viability of microbial cells-and identifies the mechanisms by which this occurs. Water provides for, and maintains, cellular structures; buffers against thermodynamic extremes, at various scales; can mitigate events that are traumatic to the cell membrane, such as desiccation-rehydration, freeze-thawing and thermal shock; prevents microbial dehydration that can otherwise exacerbate oxidative damage; mitigates against biocidal factors (in some circumstances reducing ultraviolet radiation and diluting solute stressors or toxic substances); and is effective at electrostatic screening so prevents damage to the cell by the intense electrostatic fields of some ions. In addition, the water retained in desiccated cells (historically referred to as 'bound' water) plays key roles in biomacromolecular structures and their interactions even for fully hydrated cells. Assuming that the components of the cell membrane are chemically stable or at least repairable, and the environment is fairly constant, water molecules can apparently maintain membrane geometries over very long periods provided these configurations represent thermodynamically stable states. The spores and vegetative cells of many microbes survive longer in the presence of vapour-phase water (at moderate-to-high relative humidities) than under more-arid conditions. There are several mechanisms by which large bodies of water, when cooled during subzero weather conditions remain in a liquid state thus preventing potentially dangerous (freeze-thaw) transitions for their microbiome. Microbial life can be preserved in pure water, freshwater systems, seawater, brines, ice/permafrost, sugar-rich aqueous milieux and vapour-phase water according to laboratory-based studies carried out over periods of years to decades and some natural environments that have yielded cells that are apparently thousands, or even (for hypersaline fluid inclusions of mineralized NaCl) hundreds of millions, of years old. The term preservative has often been restricted to those substances used to extend the shelf life of foods (e.g. sodium benzoate, nitrites and sulphites) or those used to conserve dead organisms, such as ethanol or formaldehyde. For living microorganisms however, the ultimate preservative may actually be water. Implications of this role are discussed with reference to the ecology of halophiles, human pathogens and other microbes; food science; biotechnology; biosignatures for life and other aspects of astrobiology; and the large-scale release/reactivation of preserved microbes caused by global climate change.
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Affiliation(s)
- John E. Hallsworth
- Institute for Global Food SecuritySchool of Biological SciencesQueen’s University Belfast19 Chlorine GardensBelfastBT9 5DLUK
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Hallsworth JE. Mars' surface is not universally biocidal. Environ Microbiol 2021; 23:3345-3350. [DOI: 10.1111/1462-2920.15494] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 03/24/2021] [Accepted: 03/26/2021] [Indexed: 12/19/2022]
Affiliation(s)
- John E. Hallsworth
- Institute for Global Food Security, School of Biological Sciences Queen's University Belfast 19 Chlorine Gardens Belfast BT9 7BL UK
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12
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Alarico S, Nunes-Costa D, Silva A, Costa M, Macedo-Ribeiro S, Empadinhas N. A genuine mycobacterial thermophile: Mycobacterium hassiacum growth, survival and GpgS stability at near-pasteurization temperatures. MICROBIOLOGY-SGM 2021; 166:474-483. [PMID: 32100712 DOI: 10.1099/mic.0.000898] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Mycobacterium hassiacum is so far the most thermophilic among mycobacteria as it grows optimally at 50 °C and up to 65 °C in a glycerol-based medium, as verified in this study. Since this and other nontuberculous mycobacteria (NTM) thrive in diverse natural and artificial environments, from where they may access and infect humans, we deemed essential to probe M. hassiacum resistance to heat, a strategy routinely used to control microbial growth in water-supply systems, as well as in the food and drink industries. In addition to possibly being a threat in its own right in rare occasions, M. hassiacum is also a good surrogate for studying other NTM species more often associated with opportunistic infection, namely Mycobacterium avium and Mycobacterium abscessus as well as their strictly pathogenic counterparts Mycobacterium tuberculosis and Mycobacterium leprae. In this regard, this thermophilic species is likely to be useful as a source of stable proteins that may provide more detailed structures of potential drug targets. Here, we investigate M. hassiacum growth at near-pasteurization temperatures and at different pHs and also characterize its thermostable glucosyl-3-phosphoglycerate synthase (GpgS), an enzyme considered essential for M. tuberculosis growth and associated with both nitrogen starvation and thermal stress in different NTM species.
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Affiliation(s)
- Susana Alarico
- IIIUC - Institute for Interdisciplinary Research, University of Coimbra, Coimbra, Portugal.,CNC - Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
| | - Daniela Nunes-Costa
- CNC - Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.,PDBEB - PhD Programme in Biomedicine and Experimental Biology, Institute for Interdisciplinary Research, University of Coimbra, Coimbra, Portugal
| | - Alexandra Silva
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.,IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
| | - Mafalda Costa
- CNC - Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
| | - Sandra Macedo-Ribeiro
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.,IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
| | - Nuno Empadinhas
- CNC - Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.,IIIUC - Institute for Interdisciplinary Research, University of Coimbra, Coimbra, Portugal
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13
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Ethanol in Combination with Oxidative Stress Significantly Impacts Mycobacterial Physiology. J Bacteriol 2020; 202:JB.00222-20. [PMID: 32928928 DOI: 10.1128/jb.00222-20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Accepted: 09/02/2020] [Indexed: 11/20/2022] Open
Abstract
Here, we investigate the mycobacterial response to the combined stress of an organic oxidant (cumene hydroperoxide [CHP]) and a solvent (ethanol). To understand the interaction between the two stressors, we treated Mycobacterium smegmatis cells to a range of ethanol concentrations (2.5% to 10% [vol/vol]) in combination with a subinhibitory concentration of 1 mM CHP. It was observed that the presence of CHP increases the efficacy of ethanol in inducing rapid cell death. The data further suggest that ethanol reacts with the alkoxy radicals to produce ethanol-derived peroxides. These radicals induce significant membrane damage and lead to cell lysis. The ethanol-derived radicals were primarily recognized by the cells as organic radicals, as was evident by the differential upregulation of the ohr-ohrR genes that function in cells treated with the combination of ethanol and CHP. The role of organic peroxide reductase, Ohr, was further confirmed by the significantly higher sensitivity of the deletion mutant to CHP and the combined stress treatment of CHP and ethanol. Moreover, we also observed the sigma factor σB to be important for the cells treated with ethanol alone as well as the aforementioned combination. A ΔsigB mutant strain had significantly higher susceptibility to the stress conditions. This finding was correlated with the σB-dependent transcriptional regulation of ohr and ohrR In summary, our data indicate that the combination of low levels of ethanol and organic peroxides induce ethanol-derived organic radicals that lead to significant oxidative stress on the cells in a concentration-dependent manner.IMPORTANCE Bacterial response to a combination of stresses can be unexpected and very different compared with that of an individual stress treatment. This study explores the physiological and transcriptional response of mycobacteria in response to the combinatorial treatment of an oxidant with the commonly used solvent ethanol. The presence of a subinhibitory concentration of organic peroxide increases the effectiveness of ethanol by inducing reactive peroxides that destroy the membrane integrity of cells in a significantly short time span. Our work elucidates a mechanism of targeting the complex mycobacterial membrane, which is its primary source of intrinsic resistance. Furthermore, it also demonstrates the importance of exploring the effect of various stress conditions on inducing bacterial clearance.
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14
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Pereira AC, Ramos B, Reis AC, Cunha MV. Non-Tuberculous Mycobacteria: Molecular and Physiological Bases of Virulence and Adaptation to Ecological Niches. Microorganisms 2020; 8:microorganisms8091380. [PMID: 32916931 PMCID: PMC7563442 DOI: 10.3390/microorganisms8091380] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 09/06/2020] [Accepted: 09/07/2020] [Indexed: 12/15/2022] Open
Abstract
Non-tuberculous mycobacteria (NTM) are paradigmatic colonizers of the total environment, circulating at the interfaces of the atmosphere, lithosphere, hydrosphere, biosphere, and anthroposphere. Their striking adaptive ecology on the interconnection of multiple spheres results from the combination of several biological features related to their exclusive hydrophobic and lipid-rich impermeable cell wall, transcriptional regulation signatures, biofilm phenotype, and symbiosis with protozoa. This unique blend of traits is reviewed in this work, with highlights to the prodigious plasticity and persistence hallmarks of NTM in a wide diversity of environments, from extreme natural milieus to microniches in the human body. Knowledge on the taxonomy, evolution, and functional diversity of NTM is updated, as well as the molecular and physiological bases for environmental adaptation, tolerance to xenobiotics, and infection biology in the human and non-human host. The complex interplay between individual, species-specific and ecological niche traits contributing to NTM resilience across ecosystems are also explored. This work hinges current understandings of NTM, approaching their biology and heterogeneity from several angles and reinforcing the complexity of these microorganisms often associated with a multiplicity of diseases, including pulmonary, soft-tissue, or milliary. In addition to emphasizing the cornerstones of knowledge involving these bacteria, we identify research gaps that need to be addressed, stressing out the need for decision-makers to recognize NTM infection as a public health issue that has to be tackled, especially when considering an increasingly susceptible elderly and immunocompromised population in developed countries, as well as in low- or middle-income countries, where NTM infections are still highly misdiagnosed and neglected.
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Affiliation(s)
- André C. Pereira
- Centre for Ecology, Evolution and Environmental Changes (cE3c), Faculdade de Ciências da Universidade de Lisboa, 1749-016 Lisboa, Portugal; (A.C.P.); (B.R.); (A.C.R.)
- Biosystems & Integrative Sciences Institute (BioISI), Faculdade de Ciências da Universidade de Lisboa, 1749-016 Lisboa, Portugal
| | - Beatriz Ramos
- Centre for Ecology, Evolution and Environmental Changes (cE3c), Faculdade de Ciências da Universidade de Lisboa, 1749-016 Lisboa, Portugal; (A.C.P.); (B.R.); (A.C.R.)
- Biosystems & Integrative Sciences Institute (BioISI), Faculdade de Ciências da Universidade de Lisboa, 1749-016 Lisboa, Portugal
| | - Ana C. Reis
- Centre for Ecology, Evolution and Environmental Changes (cE3c), Faculdade de Ciências da Universidade de Lisboa, 1749-016 Lisboa, Portugal; (A.C.P.); (B.R.); (A.C.R.)
- Biosystems & Integrative Sciences Institute (BioISI), Faculdade de Ciências da Universidade de Lisboa, 1749-016 Lisboa, Portugal
| | - Mónica V. Cunha
- Centre for Ecology, Evolution and Environmental Changes (cE3c), Faculdade de Ciências da Universidade de Lisboa, 1749-016 Lisboa, Portugal; (A.C.P.); (B.R.); (A.C.R.)
- Biosystems & Integrative Sciences Institute (BioISI), Faculdade de Ciências da Universidade de Lisboa, 1749-016 Lisboa, Portugal
- Correspondence: ; Tel.: +351-217-500-000 (ext. 22461)
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15
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de Carvalho CCCR, Teixeira R, Fernandes P. Mycobacterium vaccae Adaptation to Disinfectants and Hand Sanitisers, and Evaluation of Cross-Tolerance with Antimicrobials. Antibiotics (Basel) 2020; 9:antibiotics9090544. [PMID: 32867093 PMCID: PMC7559525 DOI: 10.3390/antibiotics9090544] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 08/20/2020] [Accepted: 08/26/2020] [Indexed: 12/12/2022] Open
Abstract
Mycobacterium vaccae is being considered as an adjuvant to antituberculosis therapy, tested for the treatment of autoimmune diseases, and as an anti-depressive agent. This bacterium is ubiquitous in the environment and the widespread use of disinfectants and sanitisers may lead to its adaptation to these compounds. In the present study, M. vaccae cells adapted to these compounds mainly by making adjustments in their lipid composition and net surface charge. The modifications in the lipid composition led to changes in membrane permeability which resulted in increased tolerance towards levofloxacin, thioridazine, and omeprazole.
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Affiliation(s)
- Carla C. C. R. de Carvalho
- Department of Bioengineering, iBB–Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisbon, Portugal; (R.T.); (P.F.)
- Correspondence: ; Tel.: +351-21-841-9594
| | - Raquel Teixeira
- Department of Bioengineering, iBB–Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisbon, Portugal; (R.T.); (P.F.)
| | - Pedro Fernandes
- Department of Bioengineering, iBB–Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisbon, Portugal; (R.T.); (P.F.)
- DREAMS and Faculty of Engineering, Universidade Lusófona de Humanidades e Tecnologias, 1749-024 Lisbon, Portugal
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16
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Hamill PG, Stevenson A, McMullan PE, Williams JP, Lewis ADR, S S, Stevenson KE, Farnsworth KD, Khroustalyova G, Takemoto JY, Quinn JP, Rapoport A, Hallsworth JE. Microbial lag phase can be indicative of, or independent from, cellular stress. Sci Rep 2020; 10:5948. [PMID: 32246056 PMCID: PMC7125082 DOI: 10.1038/s41598-020-62552-4] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Accepted: 03/16/2020] [Indexed: 01/01/2023] Open
Abstract
Measures of microbial growth, used as indicators of cellular stress, are sometimes quantified at a single time-point. In reality, these measurements are compound representations of length of lag, exponential growth-rate, and other factors. Here, we investigate whether length of lag phase can act as a proxy for stress, using a number of model systems (Aspergillus penicillioides; Bacillus subtilis; Escherichia coli; Eurotium amstelodami, E. echinulatum, E. halophilicum, and E. repens; Mrakia frigida; Saccharomyces cerevisiae; Xerochrysium xerophilum; Xeromyces bisporus) exposed to mechanistically distinct types of cellular stress including low water activity, other solute-induced stresses, and dehydration-rehydration cycles. Lag phase was neither proportional to germination rate for X. bisporus (FRR3443) in glycerol-supplemented media (r2 = 0.012), nor to exponential growth-rates for other microbes. In some cases, growth-rates varied greatly with stressor concentration even when lag remained constant. By contrast, there were strong correlations for B. subtilis in media supplemented with polyethylene-glycol 6000 or 600 (r2 = 0.925 and 0.961), and for other microbial species. We also analysed data from independent studies of food-spoilage fungi under glycerol stress (Aspergillus aculeatinus and A. sclerotiicarbonarius); mesophilic/psychrotolerant bacteria under diverse, solute-induced stresses (Brochothrix thermosphacta, Enterococcus faecalis, Pseudomonas fluorescens, Salmonella typhimurium, Staphylococcus aureus); and fungal enzymes under acid-stress (Terfezia claveryi lipoxygenase and Agaricus bisporus tyrosinase). These datasets also exhibited diversity, with some strong- and moderate correlations between length of lag and exponential growth-rates; and sometimes none. In conclusion, lag phase is not a reliable measure of stress because length of lag and growth-rate inhibition are sometimes highly correlated, and sometimes not at all.
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Affiliation(s)
- Philip G Hamill
- Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, 19 Chlorine Gardens, Belfast, BT9 5DL, Northern Ireland
| | - Andrew Stevenson
- Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, 19 Chlorine Gardens, Belfast, BT9 5DL, Northern Ireland
| | - Phillip E McMullan
- Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, 19 Chlorine Gardens, Belfast, BT9 5DL, Northern Ireland
| | - James P Williams
- Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, 19 Chlorine Gardens, Belfast, BT9 5DL, Northern Ireland
| | - Abiann D R Lewis
- Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, 19 Chlorine Gardens, Belfast, BT9 5DL, Northern Ireland
| | - Sudharsan S
- Department of Chemistry, PGP College of Arts and Science, NH-7, Karur Main Road, Paramathi, Namakkal, Tamil Nadu, 637 207, India
| | - Kath E Stevenson
- Special Collections and Archives, McClay Library, Queen's University Belfast, 10 College Park Avenue, Belfast, BT7 1LP, Northern Ireland
| | - Keith D Farnsworth
- Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, 19 Chlorine Gardens, Belfast, BT9 5DL, Northern Ireland
| | - Galina Khroustalyova
- Laboratory of Cell Biology, Institute of Microbiology and Biotechnology, University of Latvia, Jelgavas Str., 1-537, LV-1004, Riga, Latvia
| | - Jon Y Takemoto
- Utah State University, Department of Biology, 5305 Old Main Hill, Logan, UT, 84322, USA
| | - John P Quinn
- Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, 19 Chlorine Gardens, Belfast, BT9 5DL, Northern Ireland
| | - Alexander Rapoport
- Laboratory of Cell Biology, Institute of Microbiology and Biotechnology, University of Latvia, Jelgavas Str., 1-537, LV-1004, Riga, Latvia
| | - John E Hallsworth
- Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, 19 Chlorine Gardens, Belfast, BT9 5DL, Northern Ireland.
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17
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Metabolomics Studies To Decipher Stress Responses in Mycobacterium smegmatis Point to a Putative Pathway of Methylated Amine Biosynthesis. J Bacteriol 2019; 201:JB.00707-18. [PMID: 31138627 DOI: 10.1128/jb.00707-18] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Accepted: 05/15/2019] [Indexed: 01/11/2023] Open
Abstract
Mycobacterium smegmatis, the saprophytic soil mycobacterium, is routinely used as a surrogate system to study the human pathogen Mycobacterium tuberculosis It has also been reported as an opportunistic pathogen in immunocompromised hosts. In addition, it can exist in several ecological setups, thereby suggesting its capacity to adapt to a variety of environmental cues. In this study, we employed untargeted proton nuclear magnetic resonance (1H-NMR)-based metabolomics to identify metabolites and metabolic pathways critical for early adaptive responses to acidic stress, oxidative stress, and nutrient starvation in Mycobacterium smegmatis We identified 31, 20, and 46 metabolites that showed significant changes in levels in response to acidic, oxidative, and nutrient starvation stresses, respectively. Pathway analyses showed significant perturbations in purine-pyrimidine, amino-acid, nicotinate-nicotinamide, and energy metabolism pathways. Besides these, differential levels of intermediary metabolites involved in α-glucan biosynthesis pathway were observed. We also detected high levels of organic osmolytes, methylamine, and betaine during nutrient starvation and oxidative stress. Further, tracing the differential levels of these osmolytes through computational search tools, gene expression studies (using reverse transcription-PCR [RT-PCR]), and enzyme assays, we detected the presence of a putative pathway of biosynthesis of betaine, methylamine, and dimethylamine previously unreported in Mycobacterium smegmatis IMPORTANCE Alterations in metabolite levels provide fast and direct means to regulate enzymatic reactions and, therefore, metabolic pathways. This study documents, for the first time, the metabolic changes that occur in Mycobacterium smegmatis as a response to three stresses, namely, acidic stress, oxidative stress, and nutrient starvation. These stresses are also faced by intracellular mycobacteria during infection and therefore may be extended to frame therapeutic interventions for pathogenic mycobacteria. In addition to the purine-pyrimidine, amino acid, nicotinate-nicotinamide, and energy metabolism pathways that were found to be affected in response to different stresses, a novel putative methylamine biosynthesis pathway was identified to be present in Mycobacterium smegmatis.
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18
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Lee CJD, McMullan PE, O'Kane CJ, Stevenson A, Santos IC, Roy C, Ghosh W, Mancinelli RL, Mormile MR, McMullan G, Banciu HL, Fares MA, Benison KC, Oren A, Dyall-Smith ML, Hallsworth JE. NaCl-saturated brines are thermodynamically moderate, rather than extreme, microbial habitats. FEMS Microbiol Rev 2018; 42:672-693. [PMID: 29893835 DOI: 10.1093/femsre/fuy026] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Accepted: 06/08/2018] [Indexed: 11/12/2022] Open
Abstract
NaCl-saturated brines such as saltern crystalliser ponds, inland salt lakes, deep-sea brines and liquids-of-deliquescence on halite are commonly regarded as a paradigm for the limit of life on Earth. There are, however, other habitats that are thermodynamically more extreme. Typically, NaCl-saturated environments contain all domains of life and perform complete biogeochemical cycling. Despite their reduced water activity, ∼0.755 at 5 M NaCl, some halophiles belonging to the Archaea and Bacteria exhibit optimum growth/metabolism in these brines. Furthermore, the recognised water-activity limit for microbial function, ∼0.585 for some strains of fungi, lies far below 0.755. Other biophysical constraints on the microbial biosphere (temperatures of >121°C; pH > 12; and high chaotropicity; e.g. ethanol at >18.9% w/v (24% v/v) and MgCl2 at >3.03 M) can prevent any cellular metabolism or ecosystem function. By contrast, NaCl-saturated environments contain biomass-dense, metabolically diverse, highly active and complex microbial ecosystems; and this underscores their moderate character. Here, we survey the evidence that NaCl-saturated brines are biologically permissive, fertile habitats that are thermodynamically mid-range rather than extreme. Indeed, were NaCl sufficiently soluble, some halophiles might grow at concentrations of up to 8 M. It may be that the finite solubility of NaCl has stabilised the genetic composition of halophile populations and limited the action of natural selection in driving halophile evolution towards greater xerophilicity. Further implications are considered for the origin(s) of life and other aspects of astrobiology.
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Affiliation(s)
- Callum J D Lee
- Institute for Global Food Security, School of Biological Sciences, MBC, Queen's University Belfast, Belfast, BT9 7BL, Northern Ireland
| | - Phillip E McMullan
- Institute for Global Food Security, School of Biological Sciences, MBC, Queen's University Belfast, Belfast, BT9 7BL, Northern Ireland
| | - Callum J O'Kane
- Institute for Global Food Security, School of Biological Sciences, MBC, Queen's University Belfast, Belfast, BT9 7BL, Northern Ireland
| | - Andrew Stevenson
- Institute for Global Food Security, School of Biological Sciences, MBC, Queen's University Belfast, Belfast, BT9 7BL, Northern Ireland
| | - Inês C Santos
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, TX 76019, USA
| | - Chayan Roy
- Department of Microbiology, Bose Institute, P-1/12 CIT Scheme VIIM, Kolkata, 700054, India
| | - Wriddhiman Ghosh
- Department of Microbiology, Bose Institute, P-1/12 CIT Scheme VIIM, Kolkata, 700054, India
| | - Rocco L Mancinelli
- BAER Institute, Mail Stop 239-4, NASA Ames Research Center, Moffett Field, CA 94035, USA
| | - Melanie R Mormile
- Department of Biological Sciences, Missouri University of Science and Technology, Rolla, MO 65401, USA
| | - Geoffrey McMullan
- Institute for Global Food Security, School of Biological Sciences, MBC, Queen's University Belfast, Belfast, BT9 7BL, Northern Ireland
| | - Horia L Banciu
- Department of Molecular Biology and Biotechnology, Faculty of Biology and Geology, Babes-Bolyai University, 400006 Cluj-Napoca, Romania
| | - Mario A Fares
- Department of Abiotic Stress, Instituto de Biología Molecular y Celular de Plantas, Consejo Superior de Investigaciones Científicas-Universidad Politécnica de Valencia, Valencia 46022, Spain.,Institute for Integrative Systems Biology (I2SysBio), Consejo Superior de Investigaciones Científicas-Universitat de Valencia (CSIC-UV), Valencia, 46980, Spain.,Department of Genetics, Smurfit Institute of Genetics, University of Dublin, Trinity College, Dublin 2, Dublin, Ireland
| | - Kathleen C Benison
- Department of Geology and Geography, West Virginia University, Morgantown, WV 26506-6300, USA
| | - Aharon Oren
- Department of Plant & Environmental Sciences, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat-Ram, Jerusalem 9190401, Israel
| | - Mike L Dyall-Smith
- Faculty of Veterinary and Agricultural Science, The University of Melbourne, Parkville, VIC 3010, Australia
| | - John E Hallsworth
- Institute for Global Food Security, School of Biological Sciences, MBC, Queen's University Belfast, Belfast, BT9 7BL, Northern Ireland
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19
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Di Capua CB, Belardinelli JM, Buchieri MV, Bortolotti A, Franceschelli JJ, Morbidoni HR. Deletion of MSMEG_1350 in Mycobacterium smegmatis causes loss of epoxy-mycolic acids, fitness alteration at low temperature and resistance to a set of mycobacteriophages. MICROBIOLOGY-SGM 2018; 164:1567-1582. [PMID: 30311878 DOI: 10.1099/mic.0.000734] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Mycobacterium smegmatis is intrinsically resistant to thiacetazone, an anti-tubercular thiourea; however we report here that it causes a mild inhibition in growth in liquid medium. Since mycolic acid biosynthesis was affected, we cloned and expressed Mycobacterium smegmatis mycolic acid methyltransferases, postulated as targets for thiacetazone in other mycobacterial species. During this analysis we identified MSMEG_1350 as the methyltransferase involved in epoxy mycolic acid synthesis since its deletion led to their total loss. Phenotypic characterization of the mutant strain showed colony morphology alterations at all temperatures, reduced growth and a slightly increased susceptibility to SDS, lipophilic and large hydrophilic drugs at 20 °C with little effect at 37 °C. No changes were detected between parental and mutant strains in biofilm formation, sliding motility or sedimentation rate. Intriguingly, we found that several mycobacteriophages severely decreased their ability to form plaques in the mutant strain. Taken together our results prove that, in spite of being a minor component of the mycolic acid pool, epoxy-mycolates are required for a proper assembly and functioning of the cell envelope. Further studies are warranted to decipher the role of epoxy-mycolates in the M. smegmatis cell envelope.
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Affiliation(s)
- Cecilia B Di Capua
- Laboratorio de Microbiología Molecular, Cátedra de Microbiología, Facultad de Ciencias Médicas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Juan M Belardinelli
- Laboratorio de Microbiología Molecular, Cátedra de Microbiología, Facultad de Ciencias Médicas, Universidad Nacional de Rosario, Rosario, Argentina.,‡Present address: Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO 80523, USA
| | - María V Buchieri
- Laboratorio de Microbiología Molecular, Cátedra de Microbiología, Facultad de Ciencias Médicas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Ana Bortolotti
- Laboratorio de Microbiología Molecular, Cátedra de Microbiología, Facultad de Ciencias Médicas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Jorgelina J Franceschelli
- Laboratorio de Microbiología Molecular, Cátedra de Microbiología, Facultad de Ciencias Médicas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Héctor R Morbidoni
- Laboratorio de Microbiología Molecular, Cátedra de Microbiología, Facultad de Ciencias Médicas, Universidad Nacional de Rosario, Rosario, Argentina
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20
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Pacífico C, Fernandes P, de Carvalho CCCR. Mycobacterial Response to Organic Solvents and Possible Implications on Cross-Resistance With Antimicrobial Agents. Front Microbiol 2018; 9:961. [PMID: 29867865 PMCID: PMC5962743 DOI: 10.3389/fmicb.2018.00961] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Accepted: 04/24/2018] [Indexed: 02/02/2023] Open
Abstract
Mycobacterium vaccae, a bacterium found in soil, has been receiving attention as adjuvant to antituberculosis treatment, vaccines and immunotherapies and even as antidepressant. This bacterium is also able to degrade several pollutants, including aromatic compounds. The increasing presence of organic solvents in the environment may lead to M. vaccae adapted populations. A possible relationship between solvent tolerance and decreased susceptibility to other types of chemicals, including antibiotics, may pose a problem during opportunistic infections. The present study thus aimed at assessing if solvent adapted cells presented higher tolerance to antibiotics and efflux pump inhibitors (EPIs). M. vaccae cells were able to thrive and grow in the presence of up 20% (v/v) glycerol, 5% (v/v) ethanol, 1% (v/v) methyl tert-butyl ether (MTBE) and 0.1% (v/v) toluene. During adaptation to increasing concentration of ethanol and MTBE, the cells changed their fatty acid profile, zeta potential and morphology. Adapted cells acquired an improved tolerance toward the EPIs thioridazine and omeprazole, but became more susceptible to the antibiotics levofloxacin and teicoplanin when compared with non-adapted cells.
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Affiliation(s)
- Cátia Pacífico
- Institute for Bioengineering and Biosciences, Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
| | - Pedro Fernandes
- Institute for Bioengineering and Biosciences, Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
- Faculty of Engineering, Universidade Lusófona, Lisbon, Portugal
| | - Carla C. C. R. de Carvalho
- Institute for Bioengineering and Biosciences, Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
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21
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Kulikova-Borovikova D, Lisi S, Dauss E, Alamae T, Buzzini P, Hallsworth JE, Rapoport A. Activity of the α-glucoside transporter Agt1 in Saccharomyces cerevisiae cells during dehydration-rehydration events. Fungal Biol 2018; 122:613-620. [PMID: 29801806 DOI: 10.1016/j.funbio.2018.03.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Revised: 03/14/2018] [Accepted: 03/16/2018] [Indexed: 11/26/2022]
Abstract
Microbial cells can enter a state of anhydrobiosis under desiccating conditions. One of the main determinants of viability during dehydration-rehydration cycles is structural integrity of the plasma membrane. Whereas much is known about phase transitions of the lipid bilayer, there is a paucity of information on changes in activity of plasma membrane proteins during dehydration-rehydration events. We selected the α-glucoside transporter Agt1 to gain insights into stress mechanisms/responses and ecophysiology during anhydrobiosis. As intracellular water content of S. cerevisiae strain 14 (a strain with moderate tolerance to dehydration-rehydration) was reduced to 1.5 g water/g dry weight, the activity of the Agt1 transporter decreased by 10-15 %. This indicates that functionality of this trans-membrane and relatively hydrophobic protein depends on water. Notably, however, levels of cell viability were retained. Prior incubation in the stress protectant xylitol increased stability of the plasma membrane but not Agt1. Studies were carried out using a comparator yeast which was highly resistant to dehydration-rehydration (S. cerevisiae strain 77). By contrast to S. cerevisiae strain 14, there was no significant reduction of Agt1 activity in S. cerevisiae strain 77 cells. These findings have implications for the ecophysiology of S. cerevisiae strains in natural and industrial systems.
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Affiliation(s)
- Diana Kulikova-Borovikova
- Laboratory of Cell Biology, Institute of Microbiology and Biotechnology, University of Latvia, Jelgavas Str., 1-537, LV-1004, Riga, Latvia
| | - Silvia Lisi
- Department of Agricultural, Food and Environmental Science & Industrial Yeasts Collection DBVPG, University of Perugia, Borgo XX Giugno 74, I-06121, Perugia, Italy
| | - Edgars Dauss
- Laboratory of Cell Biology, Institute of Microbiology and Biotechnology, University of Latvia, Jelgavas Str., 1-537, LV-1004, Riga, Latvia
| | - Tiina Alamae
- Department of Genetics, Institute of Molecular and Cell Biology, University of Tartu, Riia 23, 51010, Tartu, Estonia
| | - Pietro Buzzini
- Department of Agricultural, Food and Environmental Science & Industrial Yeasts Collection DBVPG, University of Perugia, Borgo XX Giugno 74, I-06121, Perugia, Italy
| | - John E Hallsworth
- Institute for Global Food Security, School of Biological Sciences, MBC, Queen's University Belfast, Belfast, BT9 7BL, Northern Ireland, UK
| | - Alexander Rapoport
- Laboratory of Cell Biology, Institute of Microbiology and Biotechnology, University of Latvia, Jelgavas Str., 1-537, LV-1004, Riga, Latvia.
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22
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Choi H, Lim B, Park Y, Joo W. Improvement in solvent tolerance by exogenous glycerol inPseudomonassp. BCNU 106. Lett Appl Microbiol 2017; 65:147-152. [DOI: 10.1111/lam.12754] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Revised: 04/25/2017] [Accepted: 05/02/2017] [Indexed: 11/30/2022]
Affiliation(s)
- H.J. Choi
- Department of Biology and Chemistry; Changwon National University; Changwon Korea
| | - B.R. Lim
- Department of Biology and Chemistry; Changwon National University; Changwon Korea
| | - Y.J. Park
- Department of Biology and Chemistry; Changwon National University; Changwon Korea
| | - W.H. Joo
- Department of Biology and Chemistry; Changwon National University; Changwon Korea
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23
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Stevenson A, Hamill PG, Medina Á, Kminek G, Rummel JD, Dijksterhuis J, Timson DJ, Magan N, Leong SLL, Hallsworth JE. Glycerol enhances fungal germination at the water-activity limit for life. Environ Microbiol 2017; 19:947-967. [PMID: 27631633 PMCID: PMC5363249 DOI: 10.1111/1462-2920.13530] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Revised: 09/09/2016] [Accepted: 09/12/2016] [Indexed: 11/30/2022]
Abstract
For the most-extreme fungal xerophiles, metabolic activity and cell division typically halts between 0.700 and 0.640 water activity (approximately 70.0-64.0% relative humidity). Here, we investigate whether glycerol can enhance xerophile germination under acute water-activity regimes, using an experimental system which represents the biophysical limit of Earth's biosphere. Spores from a variety of species, including Aspergillus penicillioides, Eurotium halophilicum, Xerochrysium xerophilum (formerly Chrysosporium xerophilum) and Xeromyces bisporus, were produced by cultures growing on media supplemented with glycerol (and contained up to 189 mg glycerol g dry spores-1 ). The ability of these spores to germinate, and the kinetics of germination, were then determined on a range of media designed to recreate stresses experienced in microbial habitats or anthropogenic systems (with water-activities from 0.765 to 0.575). For A. penicillioides, Eurotium amstelodami, E. halophilicum, X. xerophilum and X. bisporus, germination occurred at lower water-activities than previously recorded (0.640, 0.685, 0.651, 0.664 and 0.637 respectively). In addition, the kinetics of germination at low water-activities were substantially faster than those reported previously. Extrapolations indicated theoretical water-activity minima below these values; as low as 0.570 for A. penicillioides and X. bisporus. Glycerol is present at high concentrations (up to molar levels) in many types of microbial habitat. We discuss the likely role of glycerol in expanding the water-activity limit for microbial cell function in relation to temporal constraints and location of the microbial cell or habitat. The findings reported here have also critical implications for understanding the extremes of Earth's biosphere; for understanding the potency of disease-causing microorganisms; and in biotechnologies that operate at the limits of microbial function.
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Affiliation(s)
- Andrew Stevenson
- Institute for Global Food Security, School of Biological Sciences, MBC, Queen's University Belfast, Belfast, BT9 7BL, Northern Ireland
| | - Philip G Hamill
- Institute for Global Food Security, School of Biological Sciences, MBC, Queen's University Belfast, Belfast, BT9 7BL, Northern Ireland
| | - Ángel Medina
- Applied Mycology Group, Cranfield Soil and AgriFood Institute, Cranfield University, Cranfield, Bedford, MK43 OAL, UK
| | - Gerhard Kminek
- Independent Safety Office, European Space Agency, 2200 AG Noordwijk, The Netherlands
| | - John D Rummel
- SETI Institute, Mountain View, California, 94043, USA
| | - Jan Dijksterhuis
- CBS-KNAW Fungal Biodiversity Centre, Uppsalalaan 8, Utrecht, CT, 3584, The Netherlands
| | - David J Timson
- School of Pharmacy and Biomolecular Sciences, University of Brighton, Huxley Building, Lewes Road, Brighton, BN2 4GJ, UK
| | - Naresh Magan
- Applied Mycology Group, Cranfield Soil and AgriFood Institute, Cranfield University, Cranfield, Bedford, MK43 OAL, UK
| | - Su-Lin L Leong
- Department of Microbiology, Swedish University of Agricultural Sciences, Box 7025, Uppsala, 75007, Sweden
| | - John E Hallsworth
- Institute for Global Food Security, School of Biological Sciences, MBC, Queen's University Belfast, Belfast, BT9 7BL, Northern Ireland
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24
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Paulussen C, Hallsworth JE, Álvarez‐Pérez S, Nierman WC, Hamill PG, Blain D, Rediers H, Lievens B. Ecology of aspergillosis: insights into the pathogenic potency of Aspergillus fumigatus and some other Aspergillus species. Microb Biotechnol 2017; 10:296-322. [PMID: 27273822 PMCID: PMC5328810 DOI: 10.1111/1751-7915.12367] [Citation(s) in RCA: 177] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2015] [Revised: 04/08/2016] [Accepted: 04/18/2016] [Indexed: 01/26/2023] Open
Abstract
Fungi of the genus Aspergillus are widespread in the environment. Some Aspergillus species, most commonly Aspergillus fumigatus, may lead to a variety of allergic reactions and life-threatening systemic infections in humans. Invasive aspergillosis occurs primarily in patients with severe immunodeficiency, and has dramatically increased in recent years. There are several factors at play that contribute to aspergillosis, including both fungus and host-related factors such as strain virulence and host pulmonary structure/immune status, respectively. The environmental tenacity of Aspergilllus, its dominance in diverse microbial communities/habitats, and its ability to navigate the ecophysiological and biophysical challenges of host infection are attributable, in large part, to a robust stress-tolerance biology and exceptional capacity to generate cell-available energy. Aspects of its stress metabolism, ecology, interactions with diverse animal hosts, clinical presentations and treatment regimens have been well-studied over the past years. Here, we synthesize these findings in relation to the way in which some Aspergillus species have become successful opportunistic pathogens of human- and other animal hosts. We focus on the biophysical capabilities of Aspergillus pathogens, key aspects of their ecophysiology and the flexibility to undergo a sexual cycle or form cryptic species. Additionally, recent advances in diagnosis of the disease are discussed as well as implications in relation to questions that have yet to be resolved.
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Affiliation(s)
- Caroline Paulussen
- Laboratory for Process Microbial Ecology and Bioinspirational Management (PME&BIM)Department of Microbial and Molecular Systems (M2S)KU LeuvenCampus De NayerSint‐Katelijne‐WaverB‐2860Belgium
| | - John E. Hallsworth
- Institute for Global Food SecuritySchool of Biological SciencesMedical Biology CentreQueen's University BelfastBelfastBT9 7BLUK
| | - Sergio Álvarez‐Pérez
- Faculty of Veterinary MedicineDepartment of Animal HealthUniversidad Complutense de MadridMadridE‐28040Spain
| | | | - Philip G. Hamill
- Institute for Global Food SecuritySchool of Biological SciencesMedical Biology CentreQueen's University BelfastBelfastBT9 7BLUK
| | - David Blain
- Institute for Global Food SecuritySchool of Biological SciencesMedical Biology CentreQueen's University BelfastBelfastBT9 7BLUK
| | - Hans Rediers
- Laboratory for Process Microbial Ecology and Bioinspirational Management (PME&BIM)Department of Microbial and Molecular Systems (M2S)KU LeuvenCampus De NayerSint‐Katelijne‐WaverB‐2860Belgium
| | - Bart Lievens
- Laboratory for Process Microbial Ecology and Bioinspirational Management (PME&BIM)Department of Microbial and Molecular Systems (M2S)KU LeuvenCampus De NayerSint‐Katelijne‐WaverB‐2860Belgium
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25
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Stevenson A, Hamill PG, O'Kane CJ, Kminek G, Rummel JD, Voytek MA, Dijksterhuis J, Hallsworth JE. Aspergillus penicillioidesdifferentiation and cell division at 0.585 water activity. Environ Microbiol 2017; 19:687-697. [DOI: 10.1111/1462-2920.13597] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Revised: 11/03/2016] [Accepted: 11/16/2016] [Indexed: 12/31/2022]
Affiliation(s)
- Andrew Stevenson
- Institute for Global Food Security; School of Biological Sciences, MBC, Queen's University Belfast; Belfast BT9 7BL Northern Ireland
| | - Philip G. Hamill
- Institute for Global Food Security; School of Biological Sciences, MBC, Queen's University Belfast; Belfast BT9 7BL Northern Ireland
| | - Callum J. O'Kane
- Institute for Global Food Security; School of Biological Sciences, MBC, Queen's University Belfast; Belfast BT9 7BL Northern Ireland
| | - Gerhard Kminek
- Independent Safety Office; European Space Agency; 2200 AG Noordwijk The Netherlands
| | | | | | - Jan Dijksterhuis
- CBS-KNAW Fungal Biodiversity Centre, Uppsalalaan 8; Utrecht CT 3584 The Netherlands
| | - John E. Hallsworth
- Institute for Global Food Security; School of Biological Sciences, MBC, Queen's University Belfast; Belfast BT9 7BL Northern Ireland
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26
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Stevenson A, Hamill PG, Dijksterhuis J, Hallsworth JE. Water-, pH- and temperature relations of germination for the extreme xerophiles Xeromyces bisporus (FRR 0025), Aspergillus penicillioides (JH06THJ) and Eurotium halophilicum (FRR 2471). Microb Biotechnol 2016; 10:330-340. [PMID: 27562192 PMCID: PMC5328819 DOI: 10.1111/1751-7915.12406] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Revised: 07/22/2016] [Accepted: 07/27/2016] [Indexed: 12/01/2022] Open
Abstract
Water activity, temperature and pH are determinants for biotic activity of cellular systems, biosphere function and, indeed, for all life processes. This study was carried out at high concentrations of glycerol, which concurrently reduces water activity and acts as a stress protectant, to characterize the biophysical capabilities of the most extremely xerophilic organisms known. These were the fungal xerophiles: Xeromyces bisporus (FRR 0025), Aspergillus penicillioides (JH06THJ) and Eurotium halophilicum (FRR 2471). High‐glycerol spores were produced and germination was determined using 38 media in the 0.995–0.637 water activity range, 33 media in the 2.80–9.80 pH range and 10 incubation temperatures, from 2 to 50°C. Water activity was modified by supplementing media with glycerol+sucrose, glycerol+NaCl and glycerol+NaCl+sucrose which are known to be biologically permissive for X. bisporus, A. penicillioides and E. halophilicum respectively. The windows and rates for spore germination were quantified for water activity, pH and temperature; symmetry/asymmetry of the germination profiles were then determined in relation to supra‐ and sub‐optimal conditions; and pH‐ and temperature optima for extreme xerophilicity were quantified. The windows for spore germination were ~1 to 0.637 water activity, pH 2.80–9.80 and > 10 and < 44°C, depending on strain. Germination profiles in relation to water activity and temperature were asymmetrical because conditions known to entropically disorder cellular macromolecules, i.e. supra‐optimal water activity and high temperatures, were severely inhibitory. Implications of these processes were considered in relation to the in‐situ ecology of extreme conditions and environments; the study also raises a number of unanswered questions which suggest the need for new lines of experimentation.
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Affiliation(s)
- Andrew Stevenson
- Institute for Global Food Security, School of Biological Sciences, MBC, Queen's University Belfast, Belfast, BT9 7BL, UK
| | - Philip G Hamill
- Institute for Global Food Security, School of Biological Sciences, MBC, Queen's University Belfast, Belfast, BT9 7BL, UK
| | - Jan Dijksterhuis
- CBS-KNAW Fungal Biodiversity Centre, Uppsalalaan 8, CT 3584, Utrecht, The Netherlands
| | - John E Hallsworth
- Institute for Global Food Security, School of Biological Sciences, MBC, Queen's University Belfast, Belfast, BT9 7BL, UK
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27
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Grover S, Gupta P, Kahlon PS, Goyal S, Grover A, Dalal K, Sabeeha, Ehtesham NZ, Hasnain SE. Analyses of methyltransferases across the pathogenicity spectrum of different mycobacterial species point to an extremophile connection. MOLECULAR BIOSYSTEMS 2016; 12:1615-25. [PMID: 26983646 DOI: 10.1039/c5mb00810g] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Tuberculosis is a devastating disease, taking one human life every 20 seconds globally. We hypothesize that professional pathogens such as M.tb have acquired specific features that might assist in causing infection, persistence and transmissible pathology in their host. We have identified 121 methyltransferases (MTases) in the M.tb proteome, which use a variety of substrates - DNA, RNA, protein, intermediates of mycolic acid biosynthesis and other fatty acids - that are involved in cellular maintenance within the host. A comparative analysis of the proteome of the virulent strain H37Rv and the avirulent strain H37Ra identified 3 MTases, which displayed significant variations in terms of N-terminal extension/deletion and point mutations, possibly impacting various physicochemical properties. The cross-proteomic comparison of MTases of M.tb H37Rv with 15 different Mycobacterium species revealed the acquisition of novel MTases in a MTB complex as a function of evolution. Phylogenetic analysis revealed that these newly acquired MTases showed common roots with certain extremophiles such as halophilic and acidophilic organisms. Our results establish an evolutionary relationship of M.tb with halotolerant organisms and also the role of MTases of M.tb in withstanding the host osmotic stress, thereby pointing to their likely role in pathogenesis, virulence and niche adaptation.
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Affiliation(s)
- Sonam Grover
- Molecular Infection and Functional Biology Lab, Kusuma School of Biological Sciences, Indian Institute of Technology Delhi, Hauz Khas, New Delhi-110016, India.
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28
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Cray JA, Connor MC, Stevenson A, Houghton JDR, Rangel DEN, Cooke LR, Hallsworth JE. Biocontrol agents promote growth of potato pathogens, depending on environmental conditions. Microb Biotechnol 2016; 9:330-54. [PMID: 26880001 PMCID: PMC4835571 DOI: 10.1111/1751-7915.12349] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2015] [Revised: 12/29/2015] [Accepted: 12/31/2015] [Indexed: 11/30/2022] Open
Abstract
There is a pressing need to understand and optimize biological control so as to avoid over‐reliance on the synthetic chemical pesticides that can damage environmental and human health. This study focused on interactions between a novel biocontrol‐strain, Bacillus sp. JC12GB43, and potato‐pathogenic Phytophthora and Fusarium species. In assays carried out in vitro and on the potato tuber, the bacterium was capable of near‐complete inhibition of pathogens. This Bacillus was sufficiently xerotolerant (water activity limit for growth = 0.928) to out‐perform Phytophthora infestans (~0.960) and challenge Fusarium coeruleum (~0.847) and Fusarium sambucinum (~0.860) towards the lower limits of their growth windows. Under some conditions, however, strain JC12GB43 stimulated proliferation of the pathogens: for instance, Fusarium coeruleum growth‐rate was increased under chaotropic conditions in vitro (132 mM urea) by >100% and on tubers (2‐M glycerol) by up to 570%. Culture‐based assays involving macromolecule‐stabilizing (kosmotropic) compatible solutes provided proof‐of‐principle that the Bacillus may provide kosmotropic metabolites to the plant pathogen under conditions that destabilize macromolecular systems of the fungal cell. Whilst unprecedented, this finding is consistent with earlier reports that fungi can utilize metabolites derived from bacterial cells. Unless the antimicrobial activities of candidate biocontrol strains are assayed over a full range of field‐relevant parameters, biocontrol agents may promote plant pathogen infections and thereby reduce crop yields. These findings indicate that biocontrol activity, therefore, ought to be regarded as a mode‐of‐behaviour (dependent on prevailing conditions) rather than an inherent property of a bacterial strain.
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Affiliation(s)
- Jonathan A Cray
- Institute for Global Food Security, School of Biological Sciences, MBC, Queen's University Belfast, Belfast, BT9 7BL, Northern Ireland
| | - Mairéad C Connor
- Institute for Global Food Security, School of Biological Sciences, MBC, Queen's University Belfast, Belfast, BT9 7BL, Northern Ireland
| | - Andrew Stevenson
- Institute for Global Food Security, School of Biological Sciences, MBC, Queen's University Belfast, Belfast, BT9 7BL, Northern Ireland
| | - Jonathan D R Houghton
- Institute for Global Food Security, School of Biological Sciences, MBC, Queen's University Belfast, Belfast, BT9 7BL, Northern Ireland
| | - Drauzio E N Rangel
- Instituto de Patologia Tropical e Saúde Pública, Universidade Federal de Goiás, Goiânia, GO, 74605-050, Brazil
| | - Louise R Cooke
- Agri-Food & Biosciences Institute (AFBI), Newforge Lane, Belfast, BT9 5PX, Northern Ireland
| | - John E Hallsworth
- Institute for Global Food Security, School of Biological Sciences, MBC, Queen's University Belfast, Belfast, BT9 7BL, Northern Ireland
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29
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Bhaganna P, Bielecka A, Molinari G, Hallsworth JE. Protective role of glycerol against benzene stress: insights from the Pseudomonas putida proteome. Curr Genet 2015; 62:419-29. [PMID: 26612269 DOI: 10.1007/s00294-015-0539-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Revised: 11/04/2015] [Accepted: 11/05/2015] [Indexed: 01/09/2023]
Abstract
Chemical activities of hydrophobic substances can determine the windows of environmental conditions over which microbial systems function and the metabolic inhibition of microorganisms by benzene and other hydrophobes can, paradoxically, be reduced by compounds that protect against cellular water stress (Bhaganna et al. in Microb Biotechnol 3:701-716, 2010; Cray et al. in Curr Opin Biotechnol 33:228-259, 2015a). We hypothesized that this protective effect operates at the macromolecule structure-function level and is facilitated, in part at least, by genome-mediated adaptations. Based on proteome profiling of the soil bacterium Pseudomonas putida, we present evidence that (1) benzene induces a chaotrope-stress response, whereas (2) cells cultured in media supplemented with benzene plus glycerol were protected against chaotrope stress. Chaotrope-stress response proteins, such as those involved in lipid and compatible-solute metabolism and removal of reactive oxygen species, were increased by up to 15-fold in benzene-stressed cells relative to those of control cultures (no benzene added). By contrast, cells grown in the presence of benzene + glycerol, even though the latter grew more slowly, exhibited only a weak chaotrope-stress response. These findings provide evidence to support the hypothesis that hydrophobic substances induce a chaotropicity-mediated water stress, that cells respond via genome-mediated adaptations, and that glycerol protects the cell's macromolecular systems. We discuss the possibility of using compatible solutes to mitigate hydrocarbon-induced stresses in lignocellulosic biofuel fermentations and for industrial and environmental applications.
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Affiliation(s)
- Prashanth Bhaganna
- MBC, School of Biological Sciences, Institute for Global Food Security, Queen's University Belfast, Belfast, BT9 7BL, Northern Ireland, UK
| | - Agata Bielecka
- Environmental Microbiology Laboratory, Helmholtz Centre for Infection Research, D-38124, Braunschweig, Germany
- Molecular Biology Department, Helmholtz Centre for Infection Research, D-38124, Braunschweig, Germany
| | - Gabriella Molinari
- Environmental Microbiology Laboratory, Helmholtz Centre for Infection Research, D-38124, Braunschweig, Germany
- Central Facility for Microscopy, Helmholtz Centre for Infection Research, D-38124, Braunschweig, Germany
| | - John E Hallsworth
- MBC, School of Biological Sciences, Institute for Global Food Security, Queen's University Belfast, Belfast, BT9 7BL, Northern Ireland, UK.
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30
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Concomitant osmotic and chaotropicity-induced stresses in Aspergillus wentii: compatible solutes determine the biotic window. Curr Genet 2015; 61:457-77. [DOI: 10.1007/s00294-015-0496-8] [Citation(s) in RCA: 79] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Revised: 04/28/2015] [Accepted: 05/13/2015] [Indexed: 12/17/2022]
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