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Senthil Kumar S, Johnson MDL, Wilson JE. Insights into the enigma of oral streptococci in carcinogenesis. Microbiol Mol Biol Rev 2024; 88:e0009523. [PMID: 38506551 DOI: 10.1128/mmbr.00095-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/21/2024] Open
Abstract
SUMMARYThe genus Streptococcus consists of a taxonomically diverse group of Gram-positive bacteria that have earned significant scientific interest due to their physiological and pathogenic characteristics. Within the genus Streptococcus, viridans group streptococci (VGS) play a significant role in the oral ecosystem, constituting approximately 80% of the oral biofilm. Their primary role as pioneering colonizers in the oral cavity with multifaceted interactions like adherence, metabolic signaling, and quorum sensing contributes significantly to the complex dynamics of the oral biofilm, thus shaping oral health and disease outcomes. Perturbations in oral streptococci composition drive oral dysbiosis and therefore impact host-pathogen interactions, resulting in oral inflammation and representing VGS as an opportunistic pathogen. The association of oral streptococci in tumors across distant organs, spanning the esophagus, stomach, pancreas, and colon, illuminates a potential association between oral streptococci, inflammation, and tumorigenesis. This finding emphasizes the need for further investigations into the role of oral streptococci in mucosal homeostasis and their involvement in carcinogenesis. Hence, here, we review the significance of oral streptococci in biofilm dynamics and how the perturbation may impact mucosal immunopathogenesis in the context of cancer, with a vision of exploiting oral streptococci for cancer intervention and for the development of non-invasive cancer diagnosis.
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Affiliation(s)
- Sangeetha Senthil Kumar
- Department of Immunobiology, The University of Arizona, Tucson, Arizona, USA
- The University of Arizona Cancer Center, Tucson, Arizona, USA
| | - Michael D L Johnson
- Department of Immunobiology, The University of Arizona, Tucson, Arizona, USA
- Valley Fever Center for Excellence, The University of Arizona College of Medicine, Tucson, Arizona, USA
- BIO5 Institute, The University of Arizona College of Medicine, Tucson, Arizona, USA
- Asthma and Airway Disease Research Center, The University of Arizona College of Medicine, Tucson, Arizona, USA
| | - Justin E Wilson
- Department of Immunobiology, The University of Arizona, Tucson, Arizona, USA
- The University of Arizona Cancer Center, Tucson, Arizona, USA
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2
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Kang W, Xiao Y, Li W, Cheng A, Cheng C, Jia Z, Yu L. Paddy cultivation in degraded karst wetland soil can significantly improve the physiological and ecological functions of carbon-fixing resident microorganisms. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 909:168187. [PMID: 37972785 DOI: 10.1016/j.scitotenv.2023.168187] [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: 07/04/2023] [Revised: 10/10/2023] [Accepted: 10/27/2023] [Indexed: 11/19/2023]
Abstract
Microorganisms play an important role in carbon fixation in karst wetland soils. However, the carbon fixation capacity of karst wetland soils and active microorganisms involved in the carbon fixation process are poorly understood. In this study, carbon fixation capacity and active microorganisms involved in the fixation of inorganic carbon into organic carbon were studied in native, naturally degraded, and reclaimed karst wetland soils by the combination of stable isotope probing (SIP) and high-throughput sequencing. Under light conditions, the soil carbon fixation capacity ranked: the reclaimed wetland soil (1.58 mg C kg-1 day-1) > native wetland soil (1.43 mg C kg-1 day-1) > degraded wetland soil (0.62 mg C kg-1 day-1). In the dark, the soils ranked: the native wetland soil (0.24 mg C kg-1 day-1) > reclaimed wetland soil (0.18 mg C kg-1 day-1) > degraded wetland soil (0.06 mg C kg-1 day-1). Active microorganisms fixing inorganic carbon in the karst wetland soils were mainly Sulfurovum, Thermovirga, Dethiosulfatibacter, Allochromatium, Methylorubrum, and Bradyrhizobium. Thus, paddy cultivation can restore the carbon fixation capacity of microorganisms in the degraded karst wetland soil. This study provides an experimental basis for improving soil carbon fixation capacity and repairing degraded soil in karst wetlands.
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Affiliation(s)
- Weihua Kang
- Institute of Resource Biology and Biotechnology, Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Yutian Xiao
- Institute of Resource Biology and Biotechnology, Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Wei Li
- Institute of Resource Biology and Biotechnology, Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China; Key Laboratory of Molecular Biophysics, Ministry of Education, Wuhan 430074, China.
| | - Aoqi Cheng
- Institute of Resource Biology and Biotechnology, Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Congyu Cheng
- Institute of Resource Biology and Biotechnology, Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Zhongjun Jia
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China
| | - Longjiang Yu
- Institute of Resource Biology and Biotechnology, Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China; Key Laboratory of Molecular Biophysics, Ministry of Education, Wuhan 430074, China
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3
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Tarlak F. The Use of Predictive Microbiology for the Prediction of the Shelf Life of Food Products. Foods 2023; 12:4461. [PMID: 38137265 PMCID: PMC10743123 DOI: 10.3390/foods12244461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Revised: 11/01/2023] [Accepted: 11/23/2023] [Indexed: 12/24/2023] Open
Abstract
Microbial shelf life refers to the duration of time during which a food product remains safe for consumption in terms of its microbiological quality. Predictive microbiology is a field of science that focuses on using mathematical models and computational techniques to predict the growth, survival, and behaviour of microorganisms in food and other environments. This approach allows researchers, food producers, and regulatory bodies to assess the potential risks associated with microbial contamination and spoilage, enabling informed decisions to be made regarding food safety, quality, and shelf life. Two-step and one-step modelling approaches are modelling techniques with primary and secondary models being used, while the machine learning approach does not require using primary and secondary models for describing the quantitative behaviour of microorganisms, leading to the spoilage of food products. This comprehensive review delves into the various modelling techniques that have found applications in predictive food microbiology for estimating the shelf life of food products. By examining the strengths, limitations, and implications of the different approaches, this review provides an invaluable resource for researchers and practitioners seeking to enhance the accuracy and reliability of microbial shelf life predictions. Ultimately, a deeper understanding of these techniques promises to advance the domain of predictive food microbiology, fostering improved food safety practices, reduced waste, and heightened consumer confidence.
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Affiliation(s)
- Fatih Tarlak
- Department of Nutrition and Dietetics, Faculty of Health Sciences, Istanbul Gedik University, Kartal, Istanbul 34876, Turkey
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4
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Lu Y, Yang J, Zhang L, Chen F, Han P, Fu Y. Characteristics of bacterial community and ARG profiles in the surface and air environments in a spacecraft assembly cleanroom. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 329:121613. [PMID: 37087089 DOI: 10.1016/j.envpol.2023.121613] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 03/13/2023] [Accepted: 04/09/2023] [Indexed: 05/03/2023]
Abstract
Understanding the microbial communities and antibiotic resistance genes (ARGs) in spacecraft assembly cleanrooms is crucial for spacecraft microbial control and astronaut safety. However, there have been few reports of ARG profiles and their relationship with microbiomes in such environments. In the present study, we assessed the bacterial community and ARGs in the air dust and surface environments of a typical spacecraft assembly cleanroom. Our results show a significant difference in bacterial composition between surfaces and air dust, as they belong to two distinct ecostates. Bacillus and Acinetobacter were significantly enriched in the air samples. Bacterial community network analysis revealed lower topological parameters and robustness of bacterial networks in the air samples. We also observed different distribution patterns of some typical ARGs between surface and air dust samples. Notably, the ermB gene exhibited a relatively high copy number and was enriched in the surface environment, compared to that in the air. Overall, our study provides insight into the complex microbial community and the distribution and transfer of ARGs in spacecraft assembly cleanrooms, and offers important input for developing control strategies against ARGs.
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Affiliation(s)
- Yueying Lu
- Key Laboratory of Biomechanics and Mechanobiology (Beihang University), Ministry of Education Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing, 100083, China; International Joint Research Center of Aerospace Biotechnology & Medical Engineering, Beihang University, Beijing, 100083, China.
| | - Jianlou Yang
- Key Laboratory of Biomechanics and Mechanobiology (Beihang University), Ministry of Education Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing, 100083, China; International Joint Research Center of Aerospace Biotechnology & Medical Engineering, Beihang University, Beijing, 100083, China.
| | - Lantao Zhang
- Institute of Manned Space System and Engineering, China Academy of Space Technology, Beijing, 100094, China.
| | - Fangqi Chen
- Shen Yuan Honors College, Beihang University, Beijing, 100191, China.
| | - Pei Han
- Laboratory of Space Utilization, Technology and Engineering Center for Space Utilization, Chinese Academy of Sciences, Beijing, 100094, China.
| | - Yuming Fu
- Key Laboratory of Biomechanics and Mechanobiology (Beihang University), Ministry of Education Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing, 100083, China; State Key Laboratory of Virtual Reality Technology and Systems, School of Computer Science and Engineering, Beihang University, Beijing, 100083, China; International Joint Research Center of Aerospace Biotechnology & Medical Engineering, Beihang University, Beijing, 100083, China.
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5
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Kumar V, Mishra RK, Ghose D, Kalita A, Dhiman P, Prakash A, Thakur N, Mitra G, Chaudhari VD, Arora A, Dutta D. Free spermidine evokes superoxide radicals that manifest toxicity. eLife 2022; 11:77704. [PMID: 35416771 PMCID: PMC9038194 DOI: 10.7554/elife.77704] [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: 02/08/2022] [Accepted: 04/11/2022] [Indexed: 11/25/2022] Open
Abstract
Spermidine and other polyamines alleviate oxidative stress, yet excess spermidine seems toxic to Escherichia coli unless it is neutralized by SpeG, an enzyme for the spermidine N-acetyl transferase function. Thus, wild-type E. coli can tolerate applied exogenous spermidine stress, but ΔspeG strain of E. coli fails to do that. Here, using different reactive oxygen species (ROS) probes and performing electron paramagnetic resonance spectroscopy, we provide evidence that although spermidine mitigates oxidative stress by lowering overall ROS levels, excess of it simultaneously triggers the production of superoxide radicals, thereby causing toxicity in the ΔspeG strain. Furthermore, performing microarray experiment and other biochemical assays, we show that the spermidine-induced superoxide anions affected redox balance and iron homeostasis. Finally, we demonstrate that while RNA-bound spermidine inhibits iron oxidation, free spermidine interacts and oxidizes the iron to evoke superoxide radicals directly. Therefore, we propose that the spermidine-induced superoxide generation is one of the major causes of spermidine toxicity in E. coli.
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Affiliation(s)
- Vineet Kumar
- CSIR Institute of Microbial Technology, Chandigarh, India
| | | | | | - Arunima Kalita
- CSIR Institute of Microbial Technology, Chandigarh, India
| | - Pulkit Dhiman
- CSIR Institute of Microbial Technology, Chandigarh, India
| | - Anand Prakash
- CSIR Institute of Microbial Technology, Chandigarh, India
| | - Nirja Thakur
- CSIR Institute of Microbial Technology, Chandigarh, India
| | - Gopa Mitra
- Division of Molecular Medicine, St John's Medical College Hospital, Bangalore, India
| | | | - Amit Arora
- CSIR Institute of Microbial Technology, Chandigarh, India
| | - Dipak Dutta
- CSIR Institute of Microbial Technology, Chandigarh, India
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6
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Zainudin MHM, Singam JT, Sazili AQ, Shirai Y, Hassan MA. Indigenous cellulolytic aerobic and facultative anaerobic bacterial community enhanced the composting of rice straw and chicken manure with biochar addition. Sci Rep 2022; 12:5930. [PMID: 35396465 PMCID: PMC8993872 DOI: 10.1038/s41598-022-09789-3] [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: 10/13/2021] [Accepted: 03/28/2022] [Indexed: 12/04/2022] Open
Abstract
Microbial degradation of organic matters is crucial during the composting process. In this study, the enhancement of the composting of rice straw and chicken manure with biochar was evaluated by investigating the indigenous cellulolytic bacterial community structure during the composting process. Compared with control treatment, composting with biochar recorded higher temperature (74 °C), longer thermophilic phase (> 50 °C for 18 days) and reduced carbon (19%) with considerable micro- and macronutrients content. The bacterial community succession showed that composting with biochar was dominated by the cellulolytic Thermobifida and Nocardiopsis genera, which play an important role in lignocellulose degradation. Twenty-three cellulolytic bacterial strains were successfully isolated at different phases of the composting with biochar. The 16S rRNA gene sequencing similarity showed that they were related to Bacilluslicheniformis, Bacillussubtilis,Bacillusaerius, and Bacillushaynesii, which were known as cellulolytic bacteria and generally involved in lignocellulose degradation. Of these isolated bacteria, Bacilluslicheniformis, a facultative anaerobe, was the major bacterial strain isolated and demonstrated higher cellulase activities. The increase in temperature and reduction of carbon during the composting with biochar in this study can thus be attributed to the existence of these cellulolytic bacteria identified.
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Affiliation(s)
- Mohd Huzairi Mohd Zainudin
- Laboratory of Sustainable Animal Production and Biodiversity, Institute of Tropical Agriculture and Food Security, Universiti Putra Malaysia (UPM), 43400, Serdang, Selangor, Malaysia.
| | - Jamuna Thurai Singam
- Laboratory of Sustainable Animal Production and Biodiversity, Institute of Tropical Agriculture and Food Security, Universiti Putra Malaysia (UPM), 43400, Serdang, Selangor, Malaysia
| | - Awis Qurni Sazili
- Laboratory of Sustainable Animal Production and Biodiversity, Institute of Tropical Agriculture and Food Security, Universiti Putra Malaysia (UPM), 43400, Serdang, Selangor, Malaysia.,Department of Animal Science, Faculty of Agriculture, Universiti Putra Malaysia (UPM), 43400, Serdang, Selangor, Malaysia
| | - Yoshihito Shirai
- Department of Biological Function and Engineering, Graduate School of Life Science and System Engineering, Kyushu Institute of Technology, 2-4 Hibikino, Wakamatsu-ku, Fukuoka, 808-0196, Japan
| | - Mohd Ali Hassan
- Department of Bioprocess Technology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia (UPM), 43400, Serdang, Selangor, Malaysia.,Laboratory of Processing and Product Development, Institute of Plantation Studies, Universiti Putra Malaysia (UPM), 43400, Serdang, Selangor, Malaysia
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7
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Singh R, Chaudhary S, Yadav S, Patil SA. Protocol for bioelectrochemical enrichment, cultivation, and characterization of extreme electroactive microorganisms. STAR Protoc 2022; 3:101114. [PMID: 35118426 PMCID: PMC8792420 DOI: 10.1016/j.xpro.2021.101114] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
Electroactive microorganisms (EAMs) are a group of microbes that can access solid extracellular electron donors or acceptors via extracellular electron transfer processes. EAMs are useful in developing various microbial electrochemical technologies. This protocol describes the use of bioelectrochemical systems (BESs) to enrich EAMs at the cathode from an extreme haloalkaline habitat. It also provides information for a detailed characterization of enriched cathodic biofilms via various cross-disciplinary techniques, including electrochemical, analytical, microscopic, and gene sequencing techniques. For complete details on the use and execution of this protocol, please refer to Chaudhary et al. (2021). Detailed protocol for the electrochemical enrichment of extreme microorganisms Useful for cultivating different microbes at cathode of bioelectrochemical systems Protocols for characterizing electrotrophic biofilm and metabolic products provided These include electrochemical, analytical, microscopic, and gene sequencing techniques
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Affiliation(s)
- Ramandeep Singh
- Department of Earth and Environmental Sciences, Indian Institute of Science Education and Research Mohali (IISER Mohali), Knowledge City, Sector 81, SAS Nagar, 140306 Punjab, India
| | - Srishti Chaudhary
- Department of Earth and Environmental Sciences, Indian Institute of Science Education and Research Mohali (IISER Mohali), Knowledge City, Sector 81, SAS Nagar, 140306 Punjab, India
| | - Sukrampal Yadav
- Department of Earth and Environmental Sciences, Indian Institute of Science Education and Research Mohali (IISER Mohali), Knowledge City, Sector 81, SAS Nagar, 140306 Punjab, India
| | - Sunil A Patil
- Department of Earth and Environmental Sciences, Indian Institute of Science Education and Research Mohali (IISER Mohali), Knowledge City, Sector 81, SAS Nagar, 140306 Punjab, India
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8
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The Historical Development of Cultivation Techniques for Methanogens and Other Strict Anaerobes and Their Application in Modern Microbiology. Microorganisms 2022; 10:microorganisms10020412. [PMID: 35208865 PMCID: PMC8879435 DOI: 10.3390/microorganisms10020412] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 02/03/2022] [Accepted: 02/09/2022] [Indexed: 02/06/2023] Open
Abstract
The cultivation and investigation of strictly anaerobic microorganisms belong to the fields of anaerobic microbial physiology, microbiology, and biotechnology. Anaerobic cultivation methods differ from classic microbiological techniques in several aspects. The requirement for special instruments, which are designed to prevent the contact of the specimen with air/molecular oxygen by different means of manipulation, makes this field more challenging for general research compared to working with aerobic microorganisms. Anaerobic microbiological methods are required for many purposes, such as for the isolation and characterization of new species and their physiological examination, as well as for anaerobic biotechnological applications or medical indications. This review presents the historical development of methods for the cultivation of strictly anaerobic microorganisms focusing on methanogenic archaea, anaerobic cultivation methods that are still widely used today, novel methods for anaerobic cultivation, and almost forgotten, but still relevant, techniques.
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9
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Pashaei R, Zahedipour-Sheshglani P, Dzingelevičienė R, Abbasi S, Rees RM. Effects of pharmaceuticals on the nitrogen cycle in water and soil: a review. ENVIRONMENTAL MONITORING AND ASSESSMENT 2022; 194:105. [PMID: 35044585 PMCID: PMC8766359 DOI: 10.1007/s10661-022-09754-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Accepted: 12/31/2021] [Indexed: 06/14/2023]
Abstract
The effects of pharmaceuticals on the nitrogen cycle in water and soil have recently become an increasingly important issue for environmental research. However, a few studies have investigated the direct effects of pharmaceuticals on the nitrogen cycle in water and soil. Pharmaceuticals can contribute to inhibition and stimulation of nitrogen cycle processes in the environment. Some pharmaceuticals have no observable effect on the nitrogen cycle in water and soil while others appeared to inhibit or stimulate for it. This review reports on the most recent evidence of effects of pharmaceuticals on the nitrogen cycle processes by examination of the potential impact of pharmaceuticals on nitrogen fixation, nitrification, ammonification, denitrification, and anammox. Research studies have identified pharmaceuticals that can either inhibit or stimulate nitrification, ammonification, denitrification, and anammox. Among these, amoxicillin, chlortetracycline, ciprofloxacin, clarithromycin, enrofloxacin, erythromycin, narasin, norfloxacin, and sulfamethazine had the most significant effects on nitrogen cycle processes. This review also clearly demonstrates that some nitrogen transformation processes such as nitrification show much higher sensitivity to the presence of pharmaceuticals than other nitrogen transformations or flows such as mineralization or ammonia volatilization. We conclude by suggesting that future studies take a more comprehensive approach to report on pharmaceuticals' impact on the nitrogen cycle process.
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Affiliation(s)
- Reza Pashaei
- Marine Research Institute of Klaipeda University, Klaipeda, Lithuania
- Department of Environmental Chemistry and Bioanalytics, Faculty of Chemistry, Nicolaus Copernicus University, Torun, Poland
| | | | | | - Sajjad Abbasi
- Department of Earth Sciences, College of Science, Shiraz University, Shiraz, Iran
- Department of Radiochemistry and Environmental Chemistry, Maria Curie-Skłodowska University, Lublin, Poland
| | - Robert M. Rees
- Scotland’s Rural College (SRUC), West Mains Rd. Edinburgh, Scotland, EH9 3JG UK
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10
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Methodological advances and challenges in probiotic bacteria production: Ongoing strategies and future perspectives. Biochem Eng J 2021. [DOI: 10.1016/j.bej.2021.108199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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11
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Primary Isolation of Mycobacterium ulcerans. Methods Mol Biol 2021. [PMID: 34643898 DOI: 10.1007/978-1-0716-1779-3_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
Primary isolation of Mycobacterium ulcerans is the separation and growth of the bacterium from a mixed population either in clinical specimen or environmental specimen in pure cultures. It is a crucial activity as it can be used to monitor antimicrobial treatment, surveillance for antimicrobial resistance, and molecular epidemiology studies toward understanding pathogen ecology and transmission as well as pathogen biology. The process involves removal of unwanted fast-growing bacteria using 5% oxalic acid, inoculation on Lowenstein-Jensen medium supplemented with glycerol, and incubation at temperatures between 30 °C and 33 °C.
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12
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Danko DC, Sierra MA, Benardini JN, Guan L, Wood JM, Singh N, Seuylemezian A, Butler DJ, Ryon K, Kuchin K, Meleshko D, Bhattacharya C, Venkateswaran KJ, Mason CE. A comprehensive metagenomics framework to characterize organisms relevant for planetary protection. MICROBIOME 2021; 9:82. [PMID: 33795001 PMCID: PMC8016160 DOI: 10.1186/s40168-021-01020-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Accepted: 02/02/2021] [Indexed: 05/07/2023]
Abstract
BACKGROUND Clean rooms of the Space Assembly Facility (SAF) at the Jet Propulsion Laboratory (JPL) at NASA are the final step of spacecraft cleaning and assembly before launching into space. Clean rooms have stringent methods of air-filtration and cleaning to minimize microbial contamination for exoplanetary research and minimize the risk of human pathogens, but they are not sterile. Clean rooms make a selective environment for microorganisms that tolerate such cleaning methods. Previous studies have attempted to characterize the microbial cargo through sequencing and culture-dependent protocols. However, there is not a standardized metagenomic workflow nor analysis pipeline for spaceflight hardware cleanroom samples to identify microbial contamination. Additionally, current identification methods fail to characterize and profile the risk of low-abundance microorganisms. RESULTS A comprehensive metagenomic framework to characterize microorganisms relevant for planetary protection in multiple cleanroom classifications (from ISO-5 to ISO-8.5) and sample types (surface, filters, and debris collected via vacuum devices) was developed. Fifty-one metagenomic samples from SAF clean rooms were sequenced and analyzed to identify microbes that could potentially survive spaceflight based on their microbial features and whether the microbes expressed any metabolic activity or growth. Additionally, an auxiliary testing was performed to determine the repeatability of our techniques and validate our analyses. We find evidence that JPL clean rooms carry microbes with attributes that may be problematic in space missions for their documented ability to withstand extreme conditions, such as psychrophilia and ability to form biofilms, spore-forming capacity, radiation resistance, and desiccation resistance. Samples from ISO-5 standard had lower microbial diversity than those conforming to ISO-6 or higher filters but still carried a measurable microbial load. CONCLUSIONS Although the extensive cleaning processes limit the number of microbes capable of withstanding clean room condition, it is important to quantify thresholds and detect organisms that can inform ongoing Planetary Protection goals, provide a biological baseline for assembly facilities, and guide future mission planning. Video Abstract.
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Affiliation(s)
- David C Danko
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY, 10065, USA
- Tri-Institutional Computational Biology & Medicine Program, Weill Cornell Medicine, New York, NY, USA
| | - Maria A Sierra
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY, 10065, USA
- The HRH Prince Alwaleed Bin Talal Bin Abdulaziz Alsaud Institute for Computational Biomedicine, Weill Cornell Medicine, New York, NY, 10065, USA
| | - James N Benardini
- Biotechnology and Planetary Protection Group, Jet Propulsion Laboratory, Pasadena, CA, 91109, USA
| | - Lisa Guan
- Biotechnology and Planetary Protection Group, Jet Propulsion Laboratory, Pasadena, CA, 91109, USA
| | - Jason M Wood
- Biotechnology and Planetary Protection Group, Jet Propulsion Laboratory, Pasadena, CA, 91109, USA
| | - Nitin Singh
- Biotechnology and Planetary Protection Group, Jet Propulsion Laboratory, Pasadena, CA, 91109, USA
| | - Arman Seuylemezian
- Biotechnology and Planetary Protection Group, Jet Propulsion Laboratory, Pasadena, CA, 91109, USA
| | - Daniel J Butler
- Tri-Institutional Computational Biology & Medicine Program, Weill Cornell Medicine, New York, NY, USA
- The HRH Prince Alwaleed Bin Talal Bin Abdulaziz Alsaud Institute for Computational Biomedicine, Weill Cornell Medicine, New York, NY, 10065, USA
| | - Krista Ryon
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY, 10065, USA
- The HRH Prince Alwaleed Bin Talal Bin Abdulaziz Alsaud Institute for Computational Biomedicine, Weill Cornell Medicine, New York, NY, 10065, USA
| | - Katerina Kuchin
- Tri-Institutional Computational Biology & Medicine Program, Weill Cornell Medicine, New York, NY, USA
- The HRH Prince Alwaleed Bin Talal Bin Abdulaziz Alsaud Institute for Computational Biomedicine, Weill Cornell Medicine, New York, NY, 10065, USA
| | - Dmitry Meleshko
- Tri-Institutional Computational Biology & Medicine Program, Weill Cornell Medicine, New York, NY, USA
- The HRH Prince Alwaleed Bin Talal Bin Abdulaziz Alsaud Institute for Computational Biomedicine, Weill Cornell Medicine, New York, NY, 10065, USA
| | - Chandrima Bhattacharya
- Tri-Institutional Computational Biology & Medicine Program, Weill Cornell Medicine, New York, NY, USA
- The HRH Prince Alwaleed Bin Talal Bin Abdulaziz Alsaud Institute for Computational Biomedicine, Weill Cornell Medicine, New York, NY, 10065, USA
| | - Kasthuri J Venkateswaran
- Biotechnology and Planetary Protection Group, Jet Propulsion Laboratory, Pasadena, CA, 91109, USA.
| | - Christopher E Mason
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY, 10065, USA.
- The HRH Prince Alwaleed Bin Talal Bin Abdulaziz Alsaud Institute for Computational Biomedicine, Weill Cornell Medicine, New York, NY, 10065, USA.
- WorldQuant Initiative for Quantitative Prediction, Weill Cornell Medicine, New York, NY, USA.
- The Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA.
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13
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S S, S R. Cyclic peptide production from lactic acid bacteria (LAB) and their diverse applications. Crit Rev Food Sci Nutr 2020; 62:2909-2927. [PMID: 33356473 DOI: 10.1080/10408398.2020.1860900] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
In recent years, cyclic peptides gave gained increasing attention owing to their pH tolerance, heat stability and resistance to enzymatic actions. The increasing outbreaks of antibiotic resistant pathogens and food spoilage have prompted researchers to search for new approaches to combat them. The increasing number of reports on novel cyclic peptides from lactic acid bacteria (LAB) is considered as a breakthrough due to their potential applications. Although an extensive investigation is required to understand the mechanism of action and range of applications, LAB cyclic peptides can be considered as potential substitutes for commercially available antibiotics and bio preservatives. This review summarizes the current updates of LAB cyclic peptides with emphasis on their structure, mode of action and applications. Recent trends in cyclic peptide applications are also discussed.
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Affiliation(s)
- Silpa S
- Department of Biotechnology, School of Bioengineering, SRM Institute of Science and Technology, Kattankalathur, Tamilnadu, India
| | - Rupachandra S
- Department of Biotechnology, School of Bioengineering, SRM Institute of Science and Technology, Kattankalathur, Tamilnadu, India
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Regberg AB, Castro CL, Connolly HC, Davis RE, Dworkin JP, Lauretta DS, Messenger SR, Mclain HL, McCubbin FM, Moore JL, Righter K, Stahl-Rommel S, Castro-Wallace SL. Prokaryotic and Fungal Characterization of the Facilities Used to Assemble, Test, and Launch the OSIRIS-REx Spacecraft. Front Microbiol 2020; 11:530661. [PMID: 33250861 PMCID: PMC7676328 DOI: 10.3389/fmicb.2020.530661] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Accepted: 09/30/2020] [Indexed: 01/04/2023] Open
Abstract
To characterize the ATLO (Assembly, Test, and Launch Operations) environment of the OSIRIS-REx spacecraft, we analyzed 17 aluminum witness foils and two blanks for bacterial, archaeal, fungal, and arthropod DNA. Under NASA’s Planetary Protection guidelines, OSIRIS-REx is a Category II outbound, Category V unrestricted sample return mission. As a result, it has no bioburden restrictions. However, the mission does have strict organic contamination requirements to achieve its primary objective of returning pristine carbonaceous asteroid regolith to Earth. Its target, near-Earth asteroid (101955) Bennu, is likely to contain organic compounds that are biologically available. Therefore, it is useful to understand what organisms were present during ATLO as part of the larger contamination knowledge effort—even though it is unlikely that any of the organisms will survive the multi-year deep space journey. Even though these samples of opportunity were not collected or preserved for DNA analysis, we successfully amplified bacterial and archaeal DNA (16S rRNA gene) from 16 of the 17 witness foils containing as few as 7 ± 3 cells per sample. Fungal DNA (ITS1) was detected in 12 of the 17 witness foils. Despite observing arthropods in some of the ATLO facilities, arthropod DNA (COI gene) was not detected. We observed 1,009 bacterial and archaeal sOTUs (sub-operational taxonomic units, 100% unique) and 167 fungal sOTUs across all of our samples (25–84 sOTUs per sample). The most abundant bacterial sOTU belonged to the genus Bacillus. This sOTU was present in blanks and may represent contamination during sample handling or storage. The sample collected from inside the fairing just prior to launch contained several unique bacterial and fungal sOTUs that describe previously uncharacterized potential for contamination during the final phase of ATLO. Additionally, fungal richness (number of sOTUs) negatively correlates with the number of carbon-bearing particles detected on samples. The total number of fungal sequences positively correlates with total amino acid concentration. These results demonstrate that it is possible to use samples of opportunity to characterize the microbiology of low-biomass environments while also revealing the limitations imposed by sample collection and preservation methods not specifically designed with biology in mind.
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Affiliation(s)
- Aaron B Regberg
- Astromaterials Research and Exploration Science Division, National Aeronautics and Space Administration (NASA) Johnson Space Center, Houston TX, United States
| | | | - Harold C Connolly
- Department of Geology, Rowan University, Glassboro, NJ, United States.,Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, United States
| | - Richard E Davis
- Jacobs@NASA/Johnson Space Center, Houston, TX, United States
| | - Jason P Dworkin
- Astrochemistry Laboratory, Goddard Space Flight Center, Greenbelt, MD, United States
| | - Dante S Lauretta
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, United States
| | - Scott R Messenger
- Astromaterials Research and Exploration Science Division, National Aeronautics and Space Administration (NASA) Johnson Space Center, Houston TX, United States
| | - Hannah L Mclain
- Astrochemistry Laboratory, Goddard Space Flight Center, Greenbelt, MD, United States
| | - Francis M McCubbin
- Astromaterials Research and Exploration Science Division, National Aeronautics and Space Administration (NASA) Johnson Space Center, Houston TX, United States
| | - Jamie L Moore
- Lockheed Martin Space Systems, Littleton, CO, United States
| | - Kevin Righter
- Astromaterials Research and Exploration Science Division, National Aeronautics and Space Administration (NASA) Johnson Space Center, Houston TX, United States
| | | | - Sarah L Castro-Wallace
- Biomedical Research and Environmental Sciences Division, Johnson Space Center, Houston, TX, United States
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Palman Y, De Leo R, Pulvirenti A, Green SJ, Hayouka Z. Antimicrobial peptide cocktail activity in minced turkey meat. Food Microbiol 2020; 92:103580. [DOI: 10.1016/j.fm.2020.103580] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 06/22/2020] [Accepted: 06/23/2020] [Indexed: 02/02/2023]
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Schwendner P, Jobson ME, Schuerger AC. Addition of anaerobic electron acceptors to solid media did not enhance growth of 125 spacecraft bacteria under simulated low-pressure Martian conditions. Sci Rep 2020; 10:18290. [PMID: 33106561 PMCID: PMC7588431 DOI: 10.1038/s41598-020-75222-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Accepted: 10/06/2020] [Indexed: 11/25/2022] Open
Abstract
To protect Mars from microbial contamination, research on growth of microorganisms found in spacecraft assembly clean rooms under simulated Martian conditions is required. This study investigated the effects of low atmospheric pressure on the growth of chemoorganotrophic spacecraft bacteria and whether the addition of Mars relevant anaerobic electron acceptors might enhance growth. The 125 bacteria screened here were recovered from actual Mars spacecraft. Growth at 7 hPa, 0 °C, and a CO2-enriched anoxic atmosphere (called low-PTA conditions) was tested on five TSA-based media supplemented with anaerobic electron acceptors. None of the 125 spacecraft bacteria showed active growth under the tested low-PTA conditions and amended media. In contrast, a decrease in viability was observed in most cases. Growth curves of two hypopiezotolerant strains, Serratia liquefaciens and Trichococcus pasteurii, were performed to quantify the effects of the added anaerobic electron acceptors. Slight variations in growth rates were determined for both bacteria. However, the final cell densities were similar for all media tested, indicating no general preference for any specific anaerobic electron acceptor. By demonstrating that a broad diversity of chemoorganotrophic and culturable spacecraft bacteria do not grow under the tested conditions, we conclude that there may be low risk of growth of chemoorganotrophic bacteria typically recovered from Mars spacecraft during planetary protection bioburden screenings.
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Affiliation(s)
- Petra Schwendner
- Space Life Sciences Lab, University of Florida, 505 Odyssey Way, Exploration Park, Merritt Island, FL, 32953, USA.
| | - Mary-Elizabeth Jobson
- Space Life Sciences Lab, University of Florida, 505 Odyssey Way, Exploration Park, Merritt Island, FL, 32953, USA
| | - Andrew C Schuerger
- Space Life Sciences Lab, University of Florida, 505 Odyssey Way, Exploration Park, Merritt Island, FL, 32953, USA
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Ssekitoleko RT, Oshabaheebwa S, Munabi IG, Tusabe MS, Namayega C, Ngabirano BA, Matovu B, Mugaga J, Reichert WM, Joloba ML. The role of medical equipment in the spread of nosocomial infections: a cross-sectional study in four tertiary public health facilities in Uganda. BMC Public Health 2020; 20:1561. [PMID: 33066745 PMCID: PMC7562759 DOI: 10.1186/s12889-020-09662-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Accepted: 10/08/2020] [Indexed: 11/11/2022] Open
Abstract
Background With many medical equipment in hospitals coming in direct contact with healthcare workers, patients, technicians, cleaners and sometimes care givers, it is important to pay close attention to their capacity in harboring potentially harmful pathogens. The goal of this study was to assess the role that medical equipment may potentially play in hospital acquired infections in four public health facilities in Uganda. Methods A cross-sectional study was conducted from December 2017 to January 2018 in four public health facilities in Uganda. Each piece of equipment from the neonatal department, imaging department or operating theatre were swabbed at three distinct points: a location in contact with the patient, a location in contact with the user, and a remote location unlikely to be contacted by either the patient or the user. The swabs were analyzed for bacterial growth using standard microbiological methods. Seventeen bacterial isolates were randomly selected and tested for susceptibility/resistance to common antibiotics. The data collected analyzed in STATA version 14. Results A total of 192 locations on 65 equipment were swabbed, with 60.4% of these locations testing positive (116/192). Nearly nine of ten equipment (57/65) tested positive for contamination in at least one location, and two out of three equipment (67.7%) tested positive in two or more locations. Of the 116 contaminated locations 52.6% were positive for Bacillus Species, 14.7% were positive for coagulase negative staphylococcus, 12.9% (15/116) were positive for E. coli, while all other bacterial species had a pooled prevalence of 19.8%. Interestingly, 55% of the remote locations were contaminated compared to 66% of the user contacted locations and 60% of the patient contacted locations. Further, 5/17 samples were resistant to at least three of the classes of antibiotics tested including penicillin, glycylcycline, tetracycline, trimethoprim sulfamethoxazole and urinary anti-infectives. Conclusion These results provides strong support for strengthening overall disinfection/sterilization practices around medical equipment use in public health facilities in Uganda. There’s also need for further research to make a direct link to the bacterial isolates identified and cases of infections recorded among patients in similar settings.
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Affiliation(s)
- Robert T Ssekitoleko
- Biomedical Engineering Unit, Department of Physiology, School of Biomedical Sciences, College of Health Sciences, Makerere University, Kampala, Uganda.
| | - Solomon Oshabaheebwa
- Biomedical Engineering Unit, Department of Physiology, School of Biomedical Sciences, College of Health Sciences, Makerere University, Kampala, Uganda
| | - Ian G Munabi
- Department of Anatomy, School of Biomedical Sciences, College of Health Sciences, Makerere University, Kampala, Uganda
| | - Martha S Tusabe
- Biomedical Engineering Unit, Department of Physiology, School of Biomedical Sciences, College of Health Sciences, Makerere University, Kampala, Uganda
| | - C Namayega
- Biomedical Engineering Unit, Department of Physiology, School of Biomedical Sciences, College of Health Sciences, Makerere University, Kampala, Uganda
| | - Beryl A Ngabirano
- Biomedical Engineering Unit, Department of Physiology, School of Biomedical Sciences, College of Health Sciences, Makerere University, Kampala, Uganda
| | - Brian Matovu
- Biomedical Engineering Unit, Department of Physiology, School of Biomedical Sciences, College of Health Sciences, Makerere University, Kampala, Uganda
| | - Julius Mugaga
- Biomedical Engineering Unit, Department of Physiology, School of Biomedical Sciences, College of Health Sciences, Makerere University, Kampala, Uganda
| | | | - Moses L Joloba
- Department of Microbiology, School of Biomedical Sciences, Makerere University college of Health Sciences, Kampala, Uganda
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Zhang Y, Zhang LT, Li ZD, Xin CX, Li XQ, Wang X, Deng YL. Microbiomes of China's Space Station During Assembly, Integration, and Test Operations. MICROBIAL ECOLOGY 2019; 78:631-650. [PMID: 30809693 DOI: 10.1007/s00248-019-01344-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Accepted: 02/13/2019] [Indexed: 06/09/2023]
Abstract
Sufficient evidence indicates that orbiting space stations contain diverse microbial populations, which may threaten astronaut health and equipment reliability. Understanding the composition of microbial communities in space stations will facilitate further development of targeted biological safety prevention and maintenance practices. Therefore, this study systematically investigated the microbial community of China's Space Station (CSS). Air and surface samples from 46 sites on the CSS and Assembly Integration and Test (AIT) center were collected, from which 40 bacteria strains were isolated and identified. Most isolates were cold- and desiccation-resistant and adapted to oligotrophic conditions. Bacillus was the dominant bacterial genus detected by both cultivation-based and Illumina MiSeq amplicon sequencing methods. Microbial contamination on the CSS was correlated with encapsulation staff activities. Analysis by spread plate and qPCR revealed that the CSS surface contained 2.24 × 103-5.47 × 103 CFU/100 cm2 culturable bacteria and 9.32 × 105-5.64 × 106 16S rRNA gene copies/100cm2; BacLight™ analysis revealed that the viable/total bacterial cell ratio was 1.98-13.28%. This is the first study to provide important systematic insights into the microbiome of the CSS during assembly that describes the pre-launch microbial diversity of the space station. Our findings revealed the following. (1) Bacillus strains and staff activities should be considered major concerns for future biological safety. (2) Autotrophic and multi-resistant microbial communities were widespread in the AIT environment. Although harsh cleaning methods reduced the number of microorganisms, stress-resistant strains were not completely removed. (3) Sampling, storage and analytical methods for the space station were thoroughly optimized, and are expected to be applicable to low-biomass environments in general. Microbiology-related future works will follow up to comprehensively understand the changing characteristics of microbial communities in CSS.
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Affiliation(s)
- Ying Zhang
- School of Life Science, Beijing Institute of Technology, Beijing, 100081, China.
| | - Lan-Tao Zhang
- Institute of Manned Space System Engineering, China Academy of Space Technology, Beijing, 100094, China
| | - Zhi-Dong Li
- Beijing Institute of Spacecraft System Engineering, Beijing, 100094, China
| | - Cong-Xin Xin
- School of Life Science, Beijing Institute of Technology, Beijing, 100081, China
| | - Xiao-Qiong Li
- School of Life Science, Beijing Institute of Technology, Beijing, 100081, China
| | - Xiang Wang
- Institute of Manned Space System Engineering, China Academy of Space Technology, Beijing, 100094, China.
| | - Yu-Lin Deng
- School of Life Science, Beijing Institute of Technology, Beijing, 100081, China.
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Habitability of Mars: How Welcoming Are the Surface and Subsurface to Life on the Red Planet? GEOSCIENCES 2019. [DOI: 10.3390/geosciences9090361] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Mars is a planet of great interest in the search for signatures of past or present life beyond Earth. The years of research, and more advanced instrumentation, have yielded a lot of evidence which may be considered by the scientific community as proof of past or present habitability of Mars. Recent discoveries including seasonal methane releases and a subglacial lake are exciting, yet challenging findings. Concurrently, laboratory and environmental studies on the limits of microbial life in extreme environments on Earth broaden our knowledge of the possibility of Mars habitability. In this review, we aim to: (1) Discuss the characteristics of the Martian surface and subsurface that may be conducive to habitability either in the past or at present; (2) discuss laboratory-based studies on Earth that provide us with discoveries on the limits of life; and (3) summarize the current state of knowledge in terms of direction for future research.
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20
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Rettberg P, Antunes A, Brucato J, Cabezas P, Collins G, Haddaji A, Kminek G, Leuko S, McKenna-Lawlor S, Moissl-Eichinger C, Fellous JL, Olsson-Francis K, Pearce D, Rabbow E, Royle S, Saunders M, Sephton M, Spry A, Walter N, Wimmer Schweingruber R, Treuet JC. Biological Contamination Prevention for Outer Solar System Moons of Astrobiological Interest: What Do We Need to Know? ASTROBIOLOGY 2019; 19:951-974. [PMID: 30762429 PMCID: PMC6767865 DOI: 10.1089/ast.2018.1996] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
To ensure that scientific investments in space exploration are not compromised by terrestrial contamination of celestial bodies, special care needs to be taken to preserve planetary conditions for future astrobiological exploration. Significant effort has been made and is being taken to address planetary protection in the context of inner Solar System exploration. In particular for missions to Mars, detailed internationally accepted guidelines have been established. For missions to the icy moons in the outer Solar System, Europa and Enceladus, the planetary protection requirements are so far based on a probabilistic approach and a conservative estimate of poorly known parameters. One objective of the European Commission-funded project, Planetary Protection of Outer Solar System, was to assess the existing planetary protection approach, to identify inherent knowledge gaps, and to recommend scientific investigations necessary to update the requirements for missions to the icy moons.
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Affiliation(s)
- Petra Rettberg
- Research Group Astrobiology, Radiation Biology Department, German Aerospace Center (DLR), Institute of Aerospace Medicine, Köln, Germany
- Address correspondence to: Petra Rettberg, German Aerospace Center (DLR), Institute of Aerospace Medicine, Radiation Biology Department, Research Group Astrobiology, Linder Höhe, 51147 Köln, Germany
| | - André Antunes
- GEMM—Group for Extreme and Marine Microbiology, Department of Biology, Edge Hill University, Ormskirk, United Kingdom
| | - John Brucato
- Department of Physics and Astronomy, Astrophysical Observatory of Arcetri, National Institute for Astrophysics (INAF), Florence, Italy
| | - Patricia Cabezas
- Science Connect–European Science Foundation (ESF), Strasbourg, France
| | - Geoffrey Collins
- Department of Physics and Astronomy, Wheaton College, Massachusetts, Norton, Massachusetts
| | - Alissa Haddaji
- Committee on Space Research (COSPAR), Montpellier, France
| | - Gerhard Kminek
- Committee on Space Research (COSPAR), Montpellier, France
| | - Stefan Leuko
- Research Group Astrobiology, Radiation Biology Department, German Aerospace Center (DLR), Institute of Aerospace Medicine, Köln, Germany
| | | | | | - Jean-Louis Fellous
- Department of Physics and Astronomy, Wheaton College, Massachusetts, Norton, Massachusetts
| | - Karen Olsson-Francis
- Faculty of Science, Technology, Engineering & Mathematics, School of Environment, Earth & Ecosystem Sciences, The Open University, Milton Keynes, United Kingdom
| | - David Pearce
- Department of Applied Sciences, Northumbria University, Newcastle, United Kingdom
| | - Elke Rabbow
- Research Group Astrobiology, Radiation Biology Department, German Aerospace Center (DLR), Institute of Aerospace Medicine, Köln, Germany
| | - Samuel Royle
- Faculty of Engineering, Department of Earth Science & Engineering, Imperial College, London, United Kingdom
| | - Mark Saunders
- Independent Consultant for the US National Academies of Sciences (NAS), Washington, District of Columbia
| | - Mark Sephton
- Faculty of Engineering, Department of Earth Science & Engineering, Imperial College, London, United Kingdom
| | - Andy Spry
- Carl Sagan Center, SETI, Mountain View, California
| | - Nicolas Walter
- Science Connect–European Science Foundation (ESF), Strasbourg, France
| | - Robert Wimmer Schweingruber
- Institut für Experimentelle und Angewandte Physik, Abteilung Extraterrestrische Physik, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
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Sánchez ÓJ, Barragán PJ, Serna L. Review of Lactobacillus in the food industry and their culture media. REVISTA COLOMBIANA DE BIOTECNOLOGÍA 2019. [DOI: 10.15446/rev.colomb.biote.v21n2.81576] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Lactic acid bacteria (LAB) are currently of great importance given their increasing use in the improvement of human and animal health and nutrition. They exhibit complex nutritional requirements, which is the reason why their production costs are high. Research efforts are being made aimed at evaluating different substrates for their production as well as the production of valuable metabolites from them. The purpose of this paper is to expose the main research and development trends for LAB production for industrial purposes with emphasis on the culture media required for their growth. The web of Science databases as well as the Google Patent Search tool were used in order to gather and analyze the scientific and technical information published in the last twelve years relating to LAB and their culture media. The use of milk, industrial cheese whey, cane molasses, hydrolyzed starches, lignocellulosic materials, organic food waste and bovine blood plasma, among others, have been proposed for Lactobacillus cultivation with the purpose of reducing costs and increasing performance in their production. Research groups and centers have the responsibility of intensifying their efforts to offer highly efficient technological alternatives to the industry that allow the production and application of LAB as a growth factor for the food sector. Also, research in prebiotic ingredients or additives derived from LAB that allow the enhancement of the benefits to the consumer must be continued. In this regard, it is necessary to increase the international visibility of Colombian scientific production in this area.
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22
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Schuerger AC, Moores JE, Smith DJ, Reitz G. A Lunar Microbial Survival Model for Predicting the Forward Contamination of the Moon. ASTROBIOLOGY 2019; 19:730-756. [PMID: 30810338 DOI: 10.1089/ast.2018.1952] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The surface conditions on the Moon are extremely harsh with high doses of ultraviolet (UV) irradiation (26.8 W · m-2 UVC/UVB), wide temperature extremes (-171°C to 140°C), low pressure (10-10 Pa), and high levels of ionizing radiation. External spacecraft surfaces on the Moon are generally >100°C during daylight hours and can reach as high as 140°C at local noon. A Lunar Microbial Survival (LMS) model was developed that estimated (1) the total viable bioburden of all spacecraft landed on the Moon as ∼4.57 × 1010 microbial cells/spores at contact, (2) the inactivation kinetics of Bacillus subtilis spores to vacuum as approaching -2 logs per 2107 days, (3) the inactivation of spores on external surfaces due to concomitant low-pressure and high-temperature conditions as -6 logs per 8 h for local noon conditions, and (4) the ionizing radiation by solar wind particles as approaching -3 logs per lunation on external surfaces only. When the biocidal factors of solar UV, vacuum, high-temperature, and ionizing radiation were combined into an integrated LMS model, a -231 log reduction in viable bioburden was predicted for external spacecraft surfaces per lunation at the equator. Results indicate that external surfaces of landed or crashed spacecraft are unlikely to harbor viable spores after only one lunation, that shallow internal surfaces will be sterilized due to the interactive effects of vacuum and thermal cycling from solar irradiation, and that deep internal surfaces would be affected only by vacuum with a degradation rate of -0.02 logs per lunation.
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Affiliation(s)
- Andrew C Schuerger
- 1 Department of Plant Pathology, University of Florida, Gainesville, Florida
| | - John E Moores
- 2 Centre for Research in Earth and Space Science (CRESS), York University, Toronto, ON Canada
| | - David J Smith
- 3 Space Biosciences Division, NASA, Ames Research Center, Moffett Field, California
| | - Günther Reitz
- 4 Department of Radiation Dosimetry, Nuclear Physics Institute of the CAS, Praha, Czech Republic
- 5 Radiation Biology Division, Institute of Aerospace Medicine, German Aerospace Center, Cologne, Germany
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Gupta A, Dutta A, Sarkar J, Panigrahi MK, Sar P. Low-Abundance Members of the Firmicutes Facilitate Bioremediation of Soil Impacted by Highly Acidic Mine Drainage From the Malanjkhand Copper Project, India. Front Microbiol 2018; 9:2882. [PMID: 30619102 PMCID: PMC6297179 DOI: 10.3389/fmicb.2018.02882] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2017] [Accepted: 11/12/2018] [Indexed: 11/16/2022] Open
Abstract
Sulfate- and iron-reducing heterotrophic bacteria represented minor proportion of the indigenous microbial community of highly acidic, oligotrophic acid mine drainage (AMD), but they can be successfully stimulated for in situ bioremediation of an AMD impacted soil (AIS). These anaerobic microorganisms although played central role in sulfate- and metal-removal, they remained inactive in the AIS due to the paucity of organic carbon and extreme acidity of the local environment. The present study investigated the scope for increasing the abundance and activity of inhabitant sulfate- and iron-reducing bacterial populations of an AIS from Malanjkhand Copper Project. An AIS of pH 3.5, high soluble SO4 2- (7838 mg/l) and Fe (179 mg/l) content was amended with nutrients (cysteine and lactate). Thorough geochemical analysis, 16S rRNA gene amplicon sequencing and qPCR highlighted the intrinsic metabolic abilities of native bacteria in AMD bioremediation. Following 180 days incubation, the nutrient amended AIS showed marked increase in pH (to 6.6) and reduction in soluble -SO4 2- (95%), -Fe (50%) and other heavy metals. Concomitant to physicochemical changes a vivid shift in microbial community composition was observed. Members of the Firmicutes present as a minor group (1.5% of total community) in AIS emerged as the single most abundant taxon (∼56%) following nutrient amendments. Organisms affiliated to Clostridiaceae, Peptococcaceae, Veillonellaceae, Christensenellaceae, Lachnospiraceae, Bacillaceae, etc. known for their fermentative, iron and sulfate reducing abilities were prevailed in the amended samples. qPCR data corroborated with this change and further revealed an increase in abundance of dissimilatory sulfite reductase gene (dsrB) and specific bacterial taxa. Involvement of these enhanced populations in reductive processes was validated by further enrichments and growth in sulfate- and iron-reducing media. Amplicon sequencing of these enrichments confirmed growth of Firmicutes members and proved their sulfate- and iron-reduction abilities. This study provided a better insight on ecological perspective of Firmicutes members within the AMD impacted sites, particularly their involvement in sulfate- and iron-reduction processes, in situ pH management and bioremediation.
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Affiliation(s)
- Abhishek Gupta
- Environmental Microbiology and Genomics Laboratory, Department of Biotechnology, Indian Institute of Technology Kharagpur, Kharagpur, India
| | - Avishek Dutta
- Environmental Microbiology and Genomics Laboratory, Department of Biotechnology, Indian Institute of Technology Kharagpur, Kharagpur, India
- School of Bioscience, Indian Institute of Technology Kharagpur, Kharagpur, India
| | - Jayeeta Sarkar
- Environmental Microbiology and Genomics Laboratory, Department of Biotechnology, Indian Institute of Technology Kharagpur, Kharagpur, India
| | - Mruganka Kumar Panigrahi
- Department of Geology and Geophysics, Indian Institute of Technology Kharagpur, Kharagpur, India
| | - Pinaki Sar
- Environmental Microbiology and Genomics Laboratory, Department of Biotechnology, Indian Institute of Technology Kharagpur, Kharagpur, India
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Li B, Li Z, Sun X, Wang Q, Xiao E, Sun W. DNA-SIP Reveals the Diversity of Chemolithoautotrophic Bacteria Inhabiting Three Different Soil Types in Typical Karst Rocky Desertification Ecosystems in Southwest China. MICROBIAL ECOLOGY 2018; 76:976-990. [PMID: 29728707 DOI: 10.1007/s00248-018-1196-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Accepted: 04/16/2018] [Indexed: 06/08/2023]
Abstract
Autotrophs that inhabit soils receive less attention than their counterparts in other ecosystems, such as deep-sea and subsurface sediments, due to the low abundance of autotrophs in soils with high organic contents. However, the karst rocky desertification region is a unique ecosystem that may have a low level of organic compounds. Therefore, we propose that karst rocky desertification ecosystems may harbor diverse autotrophic microbial communities. In this study, DNA-SIP was employed to identify the chemolithoautotrophic bacteria inhabiting three soil types (i.e., grass, forest, and agriculture) of the karst rocky desertification ecosystems. The results indicated that potential chemolithoautotrophic population was observed in each soil type, even at different time points after amending 13C-NaHCO3, confirming our hypothesis that diverse autotrophs contribute to the carbon cycle in karst soils. Bacteria, such as Ralstonia, Ochrobactrum, Brevibacterium, Acinetobacter, and Corynebacterium, demonstrated their potential to assimilate inorganic carbon and reduce nitrate or thiosulfate as electron acceptors. Putative mixotrophs were identified by DNA-SIP as well, suggesting the metabolic versatility of soil microbiota. A co-occurrence network further indicated that autotrophs and heterotrophs may form associated communities to sustain the ecosystem function. Our current study revealed the metabolic diversity of autotrophic bacteria in soil habitats and demonstrated the potentially important role of chemoautotrophs in karst rocky desertification ecosystems.
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Affiliation(s)
- Baoqin Li
- Guangdong Key Laboratory of Integrated Agro-Environmental Pollution Control and Management, Guangdong Institute of Eco-Environmental Science & Technology, 808 Tianyuan Road, Guangzhou, 510650, Guangdong, China
| | - Zhe Li
- Guangdong Key Laboratory of Integrated Agro-Environmental Pollution Control and Management, Guangdong Institute of Eco-Environmental Science & Technology, 808 Tianyuan Road, Guangzhou, 510650, Guangdong, China
| | - Xiaoxu Sun
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | - Qi Wang
- Guangdong Key Laboratory of Integrated Agro-Environmental Pollution Control and Management, Guangdong Institute of Eco-Environmental Science & Technology, 808 Tianyuan Road, Guangzhou, 510650, Guangdong, China
| | - Enzong Xiao
- Innovation Center and Key Laboratory of Waters Safety & Protection in the Pearl River Delta, Ministry of Education, Guangzhou University, Guangzhou, 510006, China
| | - Weimin Sun
- Guangdong Key Laboratory of Integrated Agro-Environmental Pollution Control and Management, Guangdong Institute of Eco-Environmental Science & Technology, 808 Tianyuan Road, Guangzhou, 510650, Guangdong, China.
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Dahunsi SO, Olayanju A, Izebere JO, Oluyori AP. Data on energy and economic evaluation and microbial assessment of anaerobic co-digestion of fruit rind of Telfairia occidentalis (Fluted pumpkin) and poultry manure. Data Brief 2018; 21:97-104. [PMID: 30338282 PMCID: PMC6186960 DOI: 10.1016/j.dib.2018.09.065] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2018] [Revised: 09/20/2018] [Accepted: 09/24/2018] [Indexed: 11/29/2022] Open
Abstract
The data described in this article was obtained in an experiment designed for the generation of biogas from the anaerobic co-digestion of Telfairia occidentalis (Fluted pumpkin) fruit rind and poultry manure both of which currently constitute an environmental nuisance in the localities where they are found. The data presented in this article is on the use of combined heat and power (CHP) system to assess the energy and economic feasibility of applying thermo-alkali pretreatment procedures to one of the substrates (Fluted pumpkin) prior to anaerobic digestion. Also, the microbial characterization and succession pattern of important microbes during the anaerobic digestion process was evaluated and the data reported in this paper.
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Affiliation(s)
- S O Dahunsi
- Faculty of Environment and Labour Safety, Ton Duc Thang University, Ho Chi Minh City, Vietnam.,Biomass and Bioenergy Group, Environment and Technology Research Cluster, Landmark University, Omu-Aran, Kwara State, Nigeria
| | - A Olayanju
- Biomass and Bioenergy Group, Environment and Technology Research Cluster, Landmark University, Omu-Aran, Kwara State, Nigeria.,Department of Agricultural and Biosystems Engineering, Landmark University, Omu-Aran, Kwara State, Nigeria
| | - J O Izebere
- Biomass and Bioenergy Group, Environment and Technology Research Cluster, Landmark University, Omu-Aran, Kwara State, Nigeria
| | - A P Oluyori
- Physical Sciences Department, Landmark University, Omu-Aran, Kwara State, Nigeria
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Pinilla-Redondo R, Riber L, Sørensen SJ. Fluorescence Recovery Allows the Implementation of a Fluorescence Reporter Gene Platform Applicable for the Detection and Quantification of Horizontal Gene Transfer in Anoxic Environments. Appl Environ Microbiol 2018; 84:e02507-17. [PMID: 29330182 PMCID: PMC5835726 DOI: 10.1128/aem.02507-17] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2017] [Accepted: 12/20/2017] [Indexed: 02/02/2023] Open
Abstract
The study of horizontal gene transfer (HGT) in microbial communities has been revolutionized by significant advances in cultivation-independent methods based on fluorescence reporter gene technologies. Recently, the combination of these novel approaches with flow cytometry has presented itself as one of the most powerful tools to study the spread of mobile genetic elements (MGEs) in the environment. However, the use of fluorescent markers, like green fluorescent protein (GFP) and mCherry, is limited by environmental constraints, such as oxygen availability and pH levels, that affect the correct maturation of their fluorophores. Few studies have characterized the effects of such environmental conditions in a systematic way, and the sheer amount of distinct protein variants requires each system to be examined in an individual fashion. The lack of efficient and reliable markers to monitor HGT in anaerobic environments, coupled to the abundance of ecologically and clinically relevant oxygen-deprived niches in which bacteria thrive, calls for the urgent development of suitable tools that permit its study. In an attempt to devise a process that allows the implementation of the mentioned dual-labeling system to anoxic milieus, the aerobic fluorescence recovery of mCherry and GFPmut3, as well as the effect of pH on their fluorescence intensities, was studied. The findings present a solution to an intrinsic problem that has long hampered the utilization of this system, highlight its pH limitations, and provide experimental tools that will help broaden its horizon of application to other fields.IMPORTANCE Many anaerobic environments, like the gastrointestinal tract, anaerobic digesters, and the interiors of dense biofilms, have been shown to be hotspots for horizontal gene transfer (HGT). Despite the increasing wealth of reports warning about the alarming spread of antibiotic resistance determinants, to date, HGT studies mainly rely on cultivation-based methods. Unfortunately, the relevance of these studies is often questionable, as only a minor fraction of bacteria can be cultivated. A recently developed approach to monitoring the fate of plasmids in microbial communities is based on a fluorescence dual-labeling system and allows the bypassing of cultivation. However, the fluorescent proteins on which it is founded are constrained by pH levels and by their strict dependence on oxygen for the maturation of their fluorophores. This study focused on the development and validation of an appropriate aerobic fluorescence recovery (AFR) method for this platform, as this embodies the missing technical link impeding its implementation in anoxic environments.
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Affiliation(s)
| | - Leise Riber
- Section of Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Søren J Sørensen
- Section of Microbiology, University of Copenhagen, Copenhagen, Denmark
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Zaikova E, Benison KC, Mormile MR, Johnson SS. Microbial communities and their predicted metabolic functions in a desiccating acid salt lake. Extremophiles 2018; 22:367-379. [PMID: 29350297 DOI: 10.1007/s00792-018-1000-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Accepted: 01/02/2018] [Indexed: 11/30/2022]
Abstract
The waters of Lake Magic in Western Australia are among the most geochemically extreme on Earth. This ephemeral saline lake is characterized by pH as low as 1.6 salinity as high as 32% total dissolved solids, and unusually complex geochemistry, including extremely high concentrations of aluminum, silica, and iron. We examined the microbial composition and putative function in this extreme acid brine environment by analyzing lake water, groundwater, and sediment samples collected during the austral summer near peak evapoconcentration. Our results reveal that the lake water metagenome, surprisingly, was comprised of mostly eukaryote sequences, particularly fungi and to a lesser extent, green algae. Groundwater and sediment samples were dominated by acidophilic Firmicutes, with eukaryotic community members only detected at low abundances. The lake water bacterial community was less diverse than that in groundwater and sediment, and was overwhelmingly represented by a single OTU affiliated with Salinisphaera. Pathways associated with halotolerance were found in the metagenomes, as were genes associated with biosynthesis of protective carotenoids. During periods of complete desiccation of the lake, we hypothesize that dormancy and entrapment in fluid inclusions in halite crystals may increase long-term survival, leading to the resilience of complex eukaryotes in this extreme environment.
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Affiliation(s)
- Elena Zaikova
- Department of Biology, Georgetown University, Washington, USA
| | - Kathleen C Benison
- Department of Geology and Geography, West Virginia University, Morgantown, USA
| | - Melanie R Mormile
- Department of Biology, Missouri University of Science and Technology, Rolla, USA
| | - Sarah Stewart Johnson
- Department of Biology, Georgetown University, Washington, USA. .,Program on Science, Technology, and International Affairs, Georgetown University, Washington, USA.
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28
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Beblo-Vranesevic K, Bohmeier M, Perras AK, Schwendner P, Rabbow E, Moissl-Eichinger C, Cockell CS, Pukall R, Vannier P, Marteinsson VT, Monaghan EP, Ehrenfreund P, Garcia-Descalzo L, Gómez F, Malki M, Amils R, Gaboyer F, Westall F, Cabezas P, Walter N, Rettberg P. The responses of an anaerobic microorganism, Yersinia intermedia MASE-LG-1 to individual and combined simulated Martian stresses. PLoS One 2017; 12:e0185178. [PMID: 29069099 PMCID: PMC5656303 DOI: 10.1371/journal.pone.0185178] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Accepted: 09/07/2017] [Indexed: 11/18/2022] Open
Abstract
The limits of life of aerobic microorganisms are well understood, but the responses of anaerobic microorganisms to individual and combined extreme stressors are less well known. Motivated by an interest in understanding the survivability of anaerobic microorganisms under Martian conditions, we investigated the responses of a new isolate, Yersinia intermedia MASE-LG-1 to individual and combined stresses associated with the Martian surface. This organism belongs to an adaptable and persistent genus of anaerobic microorganisms found in many environments worldwide. The effects of desiccation, low pressure, ionizing radiation, varying temperature, osmotic pressure, and oxidizing chemical compounds were investigated. The strain showed a high tolerance to desiccation, with a decline of survivability by four orders of magnitude during a storage time of 85 days. Exposure to X-rays resulted in dose-dependent inactivation for exposure up to 600 Gy while applied doses above 750 Gy led to complete inactivation. The effects of the combination of desiccation and irradiation were additive and the survivability was influenced by the order in which they were imposed. Ionizing irradiation and subsequent desiccation was more deleterious than vice versa. By contrast, the presence of perchlorates was not found to significantly affect the survival of the Yersinia strain after ionizing radiation. These data show that the organism has the capacity to survive and grow in physical and chemical stresses, imposed individually or in combination that are associated with Martian environment. Eventually it lost its viability showing that many of the most adaptable anaerobic organisms on Earth would be killed on Mars today.
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Affiliation(s)
- Kristina Beblo-Vranesevic
- Radiation Biology Department, Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, Germany
- * E-mail:
| | - Maria Bohmeier
- Radiation Biology Department, Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, Germany
| | - Alexandra K. Perras
- Department of Internal Medicine, Medical University of Graz, Graz, Austria
- Department of Microbiology and Archaea, University of Regensburg, Regensburg, Germany
| | - Petra Schwendner
- School of Physics and Astronomy, UK Center for Astrobiology, University of Edinburgh, Edinburgh, United Kingdom
| | - Elke Rabbow
- Radiation Biology Department, Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, Germany
| | - Christine Moissl-Eichinger
- Department of Internal Medicine, Medical University of Graz, Graz, Austria
- BioTechMed Graz, Graz, Austria
| | - Charles S. Cockell
- School of Physics and Astronomy, UK Center for Astrobiology, University of Edinburgh, Edinburgh, United Kingdom
| | - Rüdiger Pukall
- German Collection of Microorganisms and Cell Cultures, Leibniz Institute DSMZ, Braunschweig, Germany
| | | | - Viggo T. Marteinsson
- MATIS—Prokaria, Reykjavík, Iceland
- Faculty of Food Science and Nutrition, University of Iceland, Reykjavík, Iceland
| | | | - Pascale Ehrenfreund
- Leiden Observatory, Universiteit Leiden, Leiden, Netherland
- Space Policy Institute, George Washington University, Washington DC, United States of America
| | - Laura Garcia-Descalzo
- Instituto Nacional de Técnica Aeroespacial—Centro de Astrobiología (INTA-CAB), Madrid, Spain
| | - Felipe Gómez
- Instituto Nacional de Técnica Aeroespacial—Centro de Astrobiología (INTA-CAB), Madrid, Spain
| | | | | | - Frédéric Gaboyer
- Centre de Biophysique Moléculaire, Centre National de la Recherche Scientifique (CNRS), Orléans, France
| | - Frances Westall
- Centre de Biophysique Moléculaire, Centre National de la Recherche Scientifique (CNRS), Orléans, France
| | | | | | - Petra Rettberg
- Radiation Biology Department, Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, Germany
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Schwendner P, Mahnert A, Koskinen K, Moissl-Eichinger C, Barczyk S, Wirth R, Berg G, Rettberg P. Preparing for the crewed Mars journey: microbiota dynamics in the confined Mars500 habitat during simulated Mars flight and landing. MICROBIOME 2017; 5:129. [PMID: 28974259 PMCID: PMC5627443 DOI: 10.1186/s40168-017-0345-8] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Accepted: 09/18/2017] [Indexed: 05/08/2023]
Abstract
BACKGROUND The Mars500 project was conceived as the first full duration simulation of a crewed return flight to Mars. For 520 days, six crew members lived confined in a specifically designed spacecraft mock-up. The herein described "MIcrobial ecology of Confined Habitats and humAn health" (MICHA) experiment was implemented to acquire comprehensive microbiota data from this unique, confined manned habitat, to retrieve important information on the occurring microbiota dynamics, the microbial load and diversity in the air and on various surfaces. In total, 360 samples from 20 (9 air, 11 surface) locations were taken at 18 time-points and processed by extensive cultivation, PhyloChip and next generation sequencing (NGS) of 16S rRNA gene amplicons. RESULTS Cultivation assays revealed a Staphylococcus and Bacillus-dominated microbial community on various surfaces, with an average microbial load that did not exceed the allowed limits for ISS in-flight requirements indicating adequate maintenance of the facility. Areas with high human activity were identified as hotspots for microbial accumulation. Despite substantial fluctuation with respect to microbial diversity and abundance throughout the experiment, the location within the facility and the confinement duration were identified as factors significantly shaping the microbial diversity and composition, with the crew representing the main source for microbial dispersal. Opportunistic pathogens, stress-tolerant or potentially mobile element-bearing microorganisms were predicted to be prevalent throughout the confinement, while the overall microbial diversity dropped significantly over time. CONCLUSIONS Our findings clearly indicate that under confined conditions, the community structure remains a highly dynamic system which adapts to the prevailing habitat and micro-conditions. Since a sterile environment is not achievable, these dynamics need to be monitored to avoid spreading of highly resistant or potentially pathogenic microorganisms and a potentially harmful decrease of microbial diversity. If necessary, countermeasures are required, to maintain a healthy, diverse balance of beneficial, neutral and opportunistic pathogenic microorganisms. Our results serve as an important data collection for (i) future risk estimations of crewed space flight, (ii) an optimized design and planning of a spacecraft mission and (iii) for the selection of appropriate microbial monitoring approaches and potential countermeasures, to ensure a microbiologically safe space-flight environment.
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Affiliation(s)
- Petra Schwendner
- Radiation Biology Department, Institute of Aerospace Medicine, German Aerospace Center e.V. (DLR), Linder Höhe, 51147 Cologne, Germany
- Institute for Microbiology, University of Regensburg, Universitaetsstrasse 31, 93053 Regensburg, Germany
- Present address: UK Center for Astrobiology, University of Edinburgh, School of Physics and Astronomy, Peter Guthrie Tait Road, Edinburgh, EH9 3FD UK
| | - Alexander Mahnert
- Institute of Environmental Biotechnology, Graz University of Technology, Petersgasse 12/I, 8010 Graz, Austria
| | - Kaisa Koskinen
- Medical University of Graz, Department of Internal Medicine, Auenbruggerplatz 15, 8036 Graz, Austria
- BioTechMed-Graz, Mozartgasse 12/II, 8010 Graz, Austria
| | - Christine Moissl-Eichinger
- Medical University of Graz, Department of Internal Medicine, Auenbruggerplatz 15, 8036 Graz, Austria
- BioTechMed-Graz, Mozartgasse 12/II, 8010 Graz, Austria
| | - Simon Barczyk
- Radiation Biology Department, Institute of Aerospace Medicine, German Aerospace Center e.V. (DLR), Linder Höhe, 51147 Cologne, Germany
| | - Reinhard Wirth
- Institute for Microbiology, University of Regensburg, Universitaetsstrasse 31, 93053 Regensburg, Germany
| | - Gabriele Berg
- Institute of Environmental Biotechnology, Graz University of Technology, Petersgasse 12/I, 8010 Graz, Austria
| | - Petra Rettberg
- Radiation Biology Department, Institute of Aerospace Medicine, German Aerospace Center e.V. (DLR), Linder Höhe, 51147 Cologne, Germany
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Mickol RL, Page JL, Schuerger AC. Magnesium Sulfate Salt Solutions and Ices Fail to Protect Serratia liquefaciens from the Biocidal Effects of UV Irradiation under Martian Conditions. ASTROBIOLOGY 2017; 17:401-412. [PMID: 28459604 DOI: 10.1089/ast.2015.1448] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The growth of Serratia liquefaciens has been demonstrated under martian conditions of 0.7 kPa (7 mbar), 0°C, and CO2-enriched anoxic atmospheres (Schuerger et al., 2013, Astrobiology 13:115-131), but studies into the survivability of cells under hypersaline conditions that are likely to be encountered on Mars are lacking. Serratia liquefaciens cells were suspended in aqueous MgSO4 solutions, or frozen brines, and exposed to terrestrial (i.e., 101.3 kPa, 24°C, O2/N2-normal atmosphere) or martian (i.e., 0.7 kPa, -25°C, CO2-anoxic atmosphere) conditions to assess the roles of MgSO4 and UV irradiation on the survival of S. liquefaciens. Four solutions were tested for their capability to attenuate martian UV irradiation in both liquid and frozen forms: sterile deionized water (SDIW), 10 mM PO4 buffer, 5% MgSO4, and 10% MgSO4. None of the solutions in either liquid or frozen forms provided enhanced protection against martian UV irradiation. Sixty minutes of UV irradiation reduced cell densities from 2.0 × 106 cells/mL to less than 10 cells/mL for both liquid and frozen solutions. In contrast, 3-4 mm of a Mars analog soil were sufficient to attenuate 100% of UV irradiation. Results suggest that terrestrial microorganisms may not survive on Sun-exposed surfaces on Mars, even if the cells are embedded in frozen martian brines composed of MgSO4. However, if dispersed microorganisms can be covered by only a few millimeters of dust or regolith, long-term survival is probable. Key Words: Hypobaria-Mars-Planetary protection-Brines. Astrobiology 17, 401-412.
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Affiliation(s)
- Rebecca L Mickol
- 1 Center for Space and Planetary Sciences, University of Arkansas , Fayetteville, Arkansas
| | - Jessica L Page
- 2 Department of Physics and Space Science, Florida Institute of Technology , Melbourne, Florida
| | - Andrew C Schuerger
- 3 Department of Plant Pathology, University of Florida , Gainesville, Florida
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31
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Mora M, Perras A, Alekhova TA, Wink L, Krause R, Aleksandrova A, Novozhilova T, Moissl-Eichinger C. Resilient microorganisms in dust samples of the International Space Station-survival of the adaptation specialists. MICROBIOME 2016; 4:65. [PMID: 27998314 PMCID: PMC5175303 DOI: 10.1186/s40168-016-0217-7] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Accepted: 12/03/2016] [Indexed: 05/10/2023]
Abstract
BACKGROUND The International Space Station (ISS) represents a unique biotope for the human crew but also for introduced microorganisms. Microbes experience selective pressures such as microgravity, desiccation, poor nutrient-availability due to cleaning, and an increased radiation level. We hypothesized that the microbial community inside the ISS is modified by adapting to these stresses. For this reason, we analyzed 8-12 years old dust samples from Russian ISS modules with major focus on the long-time surviving portion of the microbial community. We consequently assessed the cultivable microbiota of these samples in order to analyze their extremotolerant potential against desiccation, heat-shock, and clinically relevant antibiotics. In addition, we studied the bacterial and archaeal communities from the stored Russian dust samples via molecular methods (next-generation sequencing, NGS) and compared our new data with previously derived information from the US American ISS dust microbiome. RESULTS We cultivated and identified in total 85 bacterial, non-pathogenic isolates (17 different species) and 1 fungal isolate from the 8-12 year old dust samples collected in the Russian segment of the ISS. Most of these isolates exhibited robust resistance against heat-shock and clinically relevant antibiotics. Microbial 16S rRNA gene and archaeal 16S rRNA gene targeting Next Generation Sequencing showed signatures of human-associated microorganisms (Corynebacterium, Staphylococcus, Coprococcus etc.), but also specifically adapted extremotolerant microorganisms. Besides bacteria, the detection of archaeal signatures in higher abundance was striking. CONCLUSIONS Our findings reveal (i) the occurrence of living, hardy microorganisms in archived Russian ISS dust samples, (ii) a profound resistance capacity of ISS microorganisms against environmental stresses, and (iii) the presence of archaeal signatures on board. In addition, we found indications that the microbial community in the Russian segment dust samples was different to recently reported US American ISS microbiota.
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Affiliation(s)
- Maximilian Mora
- Department for Internal Medicine, Section of Infectious Diseases and Tropical Medicine, Medical University of Graz, Auenbruggerplatz 15, 8036 Graz, Austria
| | - Alexandra Perras
- Department for Internal Medicine, Section of Infectious Diseases and Tropical Medicine, Medical University of Graz, Auenbruggerplatz 15, 8036 Graz, Austria
- Department for Microbiology, University of Regensburg, Universitätsstr. 31, 93053 Regensburg, Germany
| | | | - Lisa Wink
- Department for Internal Medicine, Section of Infectious Diseases and Tropical Medicine, Medical University of Graz, Auenbruggerplatz 15, 8036 Graz, Austria
| | - Robert Krause
- Department for Internal Medicine, Section of Infectious Diseases and Tropical Medicine, Medical University of Graz, Auenbruggerplatz 15, 8036 Graz, Austria
| | - Alina Aleksandrova
- Lomonosov Moscow State University, Leninskie Gory, 119991 Moscow, Russia
| | | | - Christine Moissl-Eichinger
- Department for Internal Medicine, Section of Infectious Diseases and Tropical Medicine, Medical University of Graz, Auenbruggerplatz 15, 8036 Graz, Austria
- BioTechMed Graz, Krenngasse 37, 8010 Graz, Austria
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Dahunsi SO, Oranusi S, Owolabi JB, Efeovbokhan VE. Comparative biogas generation from fruit peels of fluted pumpkin (Telfairia occidentalis) and its optimization. BIORESOURCE TECHNOLOGY 2016; 221:517-525. [PMID: 27686720 DOI: 10.1016/j.biortech.2016.09.065] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2016] [Revised: 09/13/2016] [Accepted: 09/15/2016] [Indexed: 06/06/2023]
Abstract
This study evaluated the potentials of fluted pumpkin fruit peels for biogas generation using three different pre-treatment methods (A, B, C) and the optimization of its process parameters. The physic-chemical characteristics of the substrates revealed it to be rich in nutrients and mineral elements needed by microorganisms. Gas chromatography analysis revealed the gas composition to be within the range of 58.5±2.5% Methane and 27±3% Carbon dioxide for all the three digestions. The study revealed that combination of three pre-treatment methods enhanced enormous biogas yield from the digested substrates as against the use of two methods and no pre-treatment experiment. Optimization of the generated biogas data revealed that RSM predicted higher gas yield than ANN, the latter gives higher accuracy and efficiency than the former. It is advocated that fluted pumpkin fruit peels be used for energy generation especially in the locations of its abundance.
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Affiliation(s)
- S O Dahunsi
- Biological Sciences Department, Landmark University, Omu-Aran, Kwara State, Nigeria
| | - S Oranusi
- Biological Sciences Department, Covenant University, Ota, Ogun State, Nigeria.
| | - J B Owolabi
- All Saints University College of Medicine, Kingstown, Saint Vincent and the Grenadines
| | - V E Efeovbokhan
- Chemical Engineering Department, Covenant University, Ota, Ogun State, Nigeria
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Mora M, Mahnert A, Koskinen K, Pausan MR, Oberauner-Wappis L, Krause R, Perras AK, Gorkiewicz G, Berg G, Moissl-Eichinger C. Microorganisms in Confined Habitats: Microbial Monitoring and Control of Intensive Care Units, Operating Rooms, Cleanrooms and the International Space Station. Front Microbiol 2016; 7:1573. [PMID: 27790191 PMCID: PMC5061736 DOI: 10.3389/fmicb.2016.01573] [Citation(s) in RCA: 90] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Accepted: 09/20/2016] [Indexed: 01/15/2023] Open
Abstract
Indoor environments, where people spend most of their time, are characterized by a specific microbial community, the indoor microbiome. Most indoor environments are connected to the natural environment by high ventilation, but some habitats are more confined: intensive care units, operating rooms, cleanrooms and the international space station (ISS) are extraordinary living and working areas for humans, with a limited exchange with the environment. The purposes for confinement are different: a patient has to be protected from infections (intensive care unit, operating room), product quality has to be assured (cleanrooms), or confinement is necessary due to extreme, health-threatening outer conditions, as on the ISS. The ISS represents the most secluded man-made habitat, constantly inhabited by humans since November 2000 – and, inevitably, also by microorganisms. All of these man-made confined habitats need to be microbiologically monitored and controlled, by e.g., microbial cleaning and disinfection. However, these measures apply constant selective pressures, which support microbes with resistance capacities against antibiotics or chemical and physical stresses and thus facilitate the rise of survival specialists and multi-resistant strains. In this article, we summarize the available data on the microbiome of aforementioned confined habitats. By comparing the different operating, maintenance and monitoring procedures as well as microbial communities therein, we emphasize the importance to properly understand the effects of confinement on the microbial diversity, the possible risks represented by some of these microorganisms and by the evolution of (antibiotic) resistances in such environments – and the need to reassess the current hygiene standards.
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Affiliation(s)
- Maximilian Mora
- Department for Internal Medicine, Medical University of Graz, Graz Austria
| | - Alexander Mahnert
- Institute of Environmental Biotechnology, Graz University of Technology, Graz Austria
| | - Kaisa Koskinen
- Department for Internal Medicine, Medical University of Graz, GrazAustria; BioTechMed-Graz, GrazAustria
| | - Manuela R Pausan
- Department for Internal Medicine, Medical University of Graz, Graz Austria
| | | | - Robert Krause
- Department for Internal Medicine, Medical University of Graz, Graz Austria
| | - Alexandra K Perras
- Department for Internal Medicine, Medical University of Graz, GrazAustria; Department for Microbiology, University of Regensburg, RegensburgGermany
| | - Gregor Gorkiewicz
- BioTechMed-Graz, GrazAustria; Department of Pathology, Medical University of Graz, GrazAustria
| | - Gabriele Berg
- Institute of Environmental Biotechnology, Graz University of Technology, Graz Austria
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Dahunsi SO, Oranusi S, Owolabi JB, Efeovbokhan VE. Mesophilic anaerobic co-digestion of poultry dropping and Carica papaya peels: Modelling and process parameter optimization study. BIORESOURCE TECHNOLOGY 2016; 216:587-600. [PMID: 27285574 DOI: 10.1016/j.biortech.2016.05.118] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Revised: 05/23/2016] [Accepted: 05/28/2016] [Indexed: 06/06/2023]
Abstract
The study evaluated anaerobic co-digestion of poultry dropping and pawpaw peels and the optimization of important process parameters. The physic-chemical analyses of the substrates were done using standard methods after application of mechanical, thermal and chemical pre-treatments methods. Gas chromatography analysis revealed the gas composition to be within the range of 66-68% methane and 18-23% carbon dioxide. The study equally revealed that combination of the different pre-treatment methods enhanced enormous biogas yield from the digestion. Optimization of the generated biogas data were carried out using the Response Surface Methodology and the Artificial Neural Networks. The coefficient of determination (R(2)) for RSM (0.9181) was lower compare to that of ANN (0.9828). This shows that ANN model gives higher accuracy than RSM model for the current. Further usage of Carica papaya peels for biogas generation is advocated.
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Affiliation(s)
- S O Dahunsi
- Biological Sciences Department, Landmark University, Nigeria.
| | - S Oranusi
- Biological Sciences Department, Covenant University, Nigeria.
| | - J B Owolabi
- All Saints University College of Medicine, Kingstown, Saint Vincent and the Grenadines
| | - V E Efeovbokhan
- Chemical Engineering Department, Covenant University, Nigeria
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Weinmaier T, Probst AJ, La Duc MT, Ciobanu D, Cheng JF, Ivanova N, Rattei T, Vaishampayan P. A viability-linked metagenomic analysis of cleanroom environments: eukarya, prokaryotes, and viruses. MICROBIOME 2015; 3:62. [PMID: 26642878 PMCID: PMC4672508 DOI: 10.1186/s40168-015-0129-y] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Accepted: 10/29/2015] [Indexed: 05/20/2023]
Abstract
BACKGROUND Recent studies posit a reciprocal dependency between the microbiomes associated with humans and indoor environments. However, none of these metagenome surveys has considered the viability of constituent microorganisms when inferring impact on human health. RESULTS Reported here are the results of a viability-linked metagenomics assay, which (1) unveil a remarkably complex community profile for bacteria, fungi, and viruses and (2) bolster the detection of underrepresented taxa by eliminating biases resulting from extraneous DNA. This approach enabled, for the first time ever, the elucidation of viral genomes from a cleanroom environment. Upon comparing the viable biomes and distribution of phylotypes within a cleanroom and adjoining (uncontrolled) gowning enclosure, the rigorous cleaning and stringent control countermeasures of the former were observed to select for a greater presence of anaerobes and spore-forming microflora. Sequence abundance and correlation analyses suggest that the viable indoor microbiome is influenced by both the human microbiome and the surrounding ecosystem(s). CONCLUSIONS The findings of this investigation constitute the literature's first ever account of the indoor metagenome derived from DNA originating solely from the potential viable microbial population. Results presented in this study should prove valuable to the conceptualization and experimental design of future studies on indoor microbiomes aimed at inferring impact on human health.
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Affiliation(s)
- Thomas Weinmaier
- Division of Computational Systems Biology, Department of Microbiology and Ecosystem Science, University of Vienna, Vienna, Austria.
| | - Alexander J Probst
- Department of Earth and Planetary Science, University of California, Berkeley, Berkeley, CA, USA.
| | - Myron T La Duc
- Biotechnology and Planetary Protection Group, Jet Propulsion Laboratory, California Institute of Technology, Pasadena, USA.
- Precis Scientific, Scottsdale, AZ, USA.
| | | | | | | | - Thomas Rattei
- Division of Computational Systems Biology, Department of Microbiology and Ecosystem Science, University of Vienna, Vienna, Austria.
| | - Parag Vaishampayan
- Biotechnology and Planetary Protection Group, Jet Propulsion Laboratory, California Institute of Technology, Pasadena, USA.
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Moissl-Eichinger C, Auerbach AK, Probst AJ, Mahnert A, Tom L, Piceno Y, Andersen GL, Venkateswaran K, Rettberg P, Barczyk S, Pukall R, Berg G. Quo vadis? Microbial profiling revealed strong effects of cleanroom maintenance and routes of contamination in indoor environments. Sci Rep 2015; 5:9156. [PMID: 25778463 PMCID: PMC4361859 DOI: 10.1038/srep09156] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Accepted: 02/11/2015] [Indexed: 01/06/2023] Open
Abstract
Space agencies maintain highly controlled cleanrooms to ensure the demands of planetary protection. To study potential effects of microbiome control, we analyzed microbial communities in two particulate-controlled cleanrooms (ISO 5 and ISO 8) and two vicinal uncontrolled areas (office, changing room) by cultivation and 16S rRNA gene amplicon analysis (cloning, pyrotagsequencing, and PhyloChip G3 analysis). Maintenance procedures affected the microbiome on total abundance and microbial community structure concerning richness, diversity and relative abundance of certain taxa. Cleanroom areas were found to be mainly predominated by potentially human-associated bacteria; archaeal signatures were detected in every area. Results indicate that microorganisms were mainly spread from the changing room (68%) into the cleanrooms, potentially carried along with human activity. The numbers of colony forming units were reduced by up to ~400 fold from the uncontrolled areas towards the ISO 5 cleanroom, accompanied with a reduction of the living portion of microorganisms from 45% (changing area) to 1% of total 16S rRNA gene signatures as revealed via propidium monoazide treatment of the samples. Our results demonstrate the strong effects of cleanroom maintenance on microbial communities in indoor environments and can be used to improve the design and operation of biologically controlled cleanrooms.
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Affiliation(s)
- Christine Moissl-Eichinger
- 1] Institute for Microbiology and Archaea Center, University of Regensburg, Universitaetsstrasse 31, 93053 Regensburg, Germany [2] Medical University Graz, Department of Internal Medicine, Auenbruggerplatz 15, 8036 Graz, Austria [3] BioTechMed Graz, Krenngasse 37, 8010 Graz, Austria
| | - Anna K Auerbach
- Institute for Microbiology and Archaea Center, University of Regensburg, Universitaetsstrasse 31, 93053 Regensburg, Germany
| | - Alexander J Probst
- Institute for Microbiology and Archaea Center, University of Regensburg, Universitaetsstrasse 31, 93053 Regensburg, Germany
| | - Alexander Mahnert
- Institute of Environmental Biotechnology, Graz University of Technology, Petersgasse 12, 8010 Graz, Austria
| | - Lauren Tom
- Lawrence Berkeley National Laboratory, Earth Sciences Division, 1 Cyclotron Rd., Berkeley, CA 94720, USA
| | - Yvette Piceno
- Lawrence Berkeley National Laboratory, Earth Sciences Division, 1 Cyclotron Rd., Berkeley, CA 94720, USA
| | - Gary L Andersen
- Lawrence Berkeley National Laboratory, Earth Sciences Division, 1 Cyclotron Rd., Berkeley, CA 94720, USA
| | | | - Petra Rettberg
- German Aerospace Center, Institute of Aerospace Medicine and Radiation Biology, Linder Höhe, 51147 Köln, Germany
| | - Simon Barczyk
- German Aerospace Center, Institute of Aerospace Medicine and Radiation Biology, Linder Höhe, 51147 Köln, Germany
| | - Rüdiger Pukall
- Leibniz Institute DSMZ - Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH, Inhoffenstraβe 7 B, 38124 Braunschweig, Germany
| | - Gabriele Berg
- Institute of Environmental Biotechnology, Graz University of Technology, Petersgasse 12, 8010 Graz, Austria
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Saleem M. Loss of Microbiome Ecological Niches and Diversity by Global Change and Trophic Downgrading. SPRINGERBRIEFS IN ECOLOGY 2015. [DOI: 10.1007/978-3-319-11665-5_4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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38
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First draft genome sequence of the amylolytic Bacillus thermoamylovorans wild-type strain 1A1 isolated from a thermophilic biogas plant. J Biotechnol 2014; 192 Pt A:154-5. [DOI: 10.1016/j.jbiotec.2014.09.017] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Accepted: 09/19/2014] [Indexed: 01/27/2023]
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39
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Draft Genome Sequence of Serratia marcescens Strain LCT-SM166, a Space Flight Strain with a Specific Carbon Source Utilization Pattern. GENOME ANNOUNCEMENTS 2014; 2:2/1/e00069-14. [PMID: 24526644 PMCID: PMC3924376 DOI: 10.1128/genomea.00069-14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Serratia marcescens has been detected in space habitats. To explore the influence of the space flight environment on this bacterium, we investigated the genome sequence of LCT-SM166, which was isolated after space flight and has a specific carbon source utilization pattern.
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40
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Kilmer BR, Eberl TC, Cunderla B, Chen F, Clark BC, Schneegurt MA. Molecular and Phenetic Characterization of the Bacterial Assemblage of Hot Lake, WA, an Environment with High Concentrations of Magnesium Sulfate, and Its Relevance to Mars. INTERNATIONAL JOURNAL OF ASTROBIOLOGY 2014; 13:69-80. [PMID: 24748851 PMCID: PMC3989109 DOI: 10.1017/s1473550413000268] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Hot Lake (Oroville, WA) is an athalassohaline epsomite lake that can have precipitating concentrations of MgSO4 salts, mainly epsomite. Little biotic study has been done on epsomite lakes and it was unclear whether microbes isolated from epsomite lakes and their margins would fall within recognized halotolerant genera, common soil genera, or novel phyla. Our initial study cultivated and characterized epsotolerant bacteria from the lake and its margins. Approximately 100 aerobic heterotrophic microbial isolates were obtained by repetitive streak-plating in high-salt media including either 10% NaCl or 2 M MgSO4. The collected isolates were all bacteria, nearly evenly divided between Gram-positive and Gram-negative clades, the most abundant genera being Halomonas, Idiomarina, Marinobacter, Marinococcus, Nesterenkonia, Nocardiopsis, and Planococcus. Bacillus, Corynebacterium, Exiguobacterium, Kocuria, and Staphylococcus also were cultured. This initial study included culture-independent community analysis of direct DNA extracts of lake margin soil using PCR-based clone libraries and 16S rRNA gene phylogeny. Clones assigned Gram-positive bacterial clades (70% of total clones) were dominated by sequences related to uncultured actinobacteria. There were abundant Deltaproteobacteria clones related to bacterial sulfur metabolisms and clones of Legionella and Coxiella. These epsomite lake microbial communities seem to be divided between bacteria primarily associated with hyperhaline environments rich in NaCl and salinotolerant relatives of common soil organisms. Archaea appear to be in low abundance and none were isolated, despite near-saturated salinities. Growth of microbes at very high concentrations of magnesium and other sulfates has relevance to planetary protection and life-detection missions to Mars, where scant liquid water may form as deliquescent brines and appear as eutectic liquids.
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Affiliation(s)
- Brian R. Kilmer
- Department of Biological Sciences, Wichita State University, Wichita, KS
| | - Timothy C. Eberl
- Department of Biological Sciences, Wichita State University, Wichita, KS
| | | | - Fei Chen
- Planetary Protection Group, Jet Propulsion Laboratory, NASA, Pasadena, CA
| | | | - Mark A. Schneegurt
- Department of Biological Sciences, Wichita State University, Wichita, KS
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41
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La Duc MT, Venkateswaran K, Conley CA. A genetic inventory of spacecraft and associated surfaces. ASTROBIOLOGY 2014; 14:15-23. [PMID: 24432775 DOI: 10.1089/ast.2013.0966] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Terrestrial organisms or other contaminants that are transported to Mars could interfere with efforts to study the potential for indigenous martian life. Similarly, contaminants that make the round-trip to Mars and back to Earth could compromise the ability to discriminate an authentic martian biosignature from a terrestrial organism. For this reason, it is important to develop a comprehensive inventory of microbes that are present on spacecraft to avoid interpreting their traces as authentic extraterrestrial biosignatures. Culture-based methods are currently used by NASA to assess spacecraft cleanliness but deliberately detect only a very small subset of total organisms present. The National Research Council has recommended that molecular (DNA)-based identification techniques should be developed as one aspect of managing the risk that terrestrial contamination could interfere with detection of life on (or returned from) Mars. The current understanding of the microbial diversity associated with spacecraft and clean room surfaces is expanding, but the capability to generate a comprehensive inventory of the microbial populations present on spacecraft outbound from Earth would address multiple considerations in planetary protection, relevant to both robotic and human missions. To this end, a 6-year genetic inventory study was undertaken by a NASA/JPL team. It was completed in 2012 and included delivery of a publicly available comprehensive final report. The genetic inventory study team evaluated the utility of three analytical technologies (conventional cloning techniques, PhyloChip DNA microarrays, and 454 tag-pyrosequencing) and combined them with a systematic methodology to collect, process, and archive nucleic acids as the first steps in assessing the phylogenetic breadth of microorganisms on spacecraft and associated surfaces.
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Affiliation(s)
- Myron T La Duc
- 1 Biotechnology and Planetary Protection Group, Jet Propulsion Laboratory, California Institute of Technology , Pasadena, California
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42
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Chang D, Zhu Y, An L, Liu J, Su L, Guo Y, Chen Z, Wang Y, Wang L, Wang J, Li T, Fang X, Fang C, Yang R, Liu C. A multi-omic analysis of an Enterococcus faecium mutant reveals specific genetic mutations and dramatic changes in mRNA and protein expression. BMC Microbiol 2013; 13:304. [PMID: 24373636 PMCID: PMC3879163 DOI: 10.1186/1471-2180-13-304] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2013] [Accepted: 12/24/2013] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND For a long time, Enterococcus faecium was considered a harmless commensal of the mammalian gastrointestinal (GI) tract and was used as a probiotic in fermented foods. In recent decades, E. faecium has been recognised as an opportunistic pathogen that causes diseases such as neonatal meningitis, urinary tract infections, bacteremia, bacterial endocarditis and diverticulitis. E. faecium could be taken into space with astronauts and exposed to the space environment. Thus, it is necessary to observe the phenotypic and molecular changes of E. faecium after spaceflight. RESULTS An E. faecium mutant with biochemical features that are different from those of the wild-type strain was obtained from subculture after flight on the SHENZHOU-8 spacecraft. To understand the underlying mechanism causing these changes, the whole genomes of both the mutant and the WT strains were sequenced using Illumina technology. The genomic comparison revealed that dprA, a recombination-mediator gene, and arpU, a gene associated with cell wall growth, were mutated. Comparative transcriptomic and proteomic analyses showed that differentially expressed genes or proteins were involved with replication, recombination, repair, cell wall biogenesis, glycometabolism, lipid metabolism, amino acid metabolism, predicted general function and energy production/conversion. CONCLUSION This study analysed the comprehensive genomic, transcriptomic and proteomic changes of an E. faecium mutant from subcultures that were loaded on the SHENZHOU-8 spacecraft. The implications of these gene mutations and expression changes and their underlying mechanisms should be investigated in the future. We hope that the current exploration of multiple "-omics" analyses of this E. faecium mutant will provide clues for future studies on this opportunistic pathogen.
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Affiliation(s)
- De Chang
- Nanlou Respiratory Diseases Department, Chinese PLA General Hospital, Beijing 100853, China
| | - Yuanfang Zhu
- BGI-Shenzhen, Shenzhen, People’s Republic of China
| | - Li An
- Nanlou Respiratory Diseases Department, Chinese PLA General Hospital, Beijing 100853, China
| | - Jinwen Liu
- BGI-Shenzhen, Shenzhen, People’s Republic of China
| | - Longxiang Su
- Nanlou Respiratory Diseases Department, Chinese PLA General Hospital, Beijing 100853, China
| | - Yinghua Guo
- Nanlou Respiratory Diseases Department, Chinese PLA General Hospital, Beijing 100853, China
| | - Zhenhong Chen
- Nanlou Respiratory Diseases Department, Chinese PLA General Hospital, Beijing 100853, China
| | - Yajuan Wang
- Nanlou Respiratory Diseases Department, Chinese PLA General Hospital, Beijing 100853, China
| | - Li Wang
- Nanlou Respiratory Diseases Department, Chinese PLA General Hospital, Beijing 100853, China
| | - Junfeng Wang
- Nanlou Respiratory Diseases Department, Chinese PLA General Hospital, Beijing 100853, China
| | - Tianzhi Li
- Nanlou Respiratory Diseases Department, Chinese PLA General Hospital, Beijing 100853, China
| | - Xiangqun Fang
- Nanlou Respiratory Diseases Department, Chinese PLA General Hospital, Beijing 100853, China
| | | | - Ruifu Yang
- BGI-Shenzhen, Shenzhen, People’s Republic of China
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, China
| | - Changting Liu
- Nanlou Respiratory Diseases Department, Chinese PLA General Hospital, Beijing 100853, China
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43
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Moissl-Eichinger C, Pukall R, Probst AJ, Stieglmeier M, Schwendner P, Mora M, Barczyk S, Bohmeier M, Rettberg P. Lessons learned from the microbial analysis of the Herschel spacecraft during assembly, integration, and test operations. ASTROBIOLOGY 2013; 13:1125-39. [PMID: 24313230 DOI: 10.1089/ast.2013.1024] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Understanding microbial diversity in spacecraft assembly clean rooms is of major interest with respect to planetary protection considerations. A coordinated screening of different clean rooms in Europe and South America by three German institutes [Deutsches Zentrum für Luft- und Raumfahrt (DLR), Leibniz-Institut DSMZ-Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH (DSMZ), and the Institute of Microbiology and Archaea Center, University of Regensburg] took place during the assembly, test, and launch operations of the Herschel spacecraft in 2006-2009. Through this campaign, we retrieved critical information regarding the microbiome within these clean rooms and on the Herschel spacecraft, which served as a model for upcoming ESA mission preparations. This "lessons learned" document summarizes and discusses the data we obtained during this sampling campaign. Additionally, we have taken the opportunity to create a database that includes all 16S rRNA gene sequences ever retrieved from molecular and cultivable diversity studies of spacecraft assembly clean rooms to compare the microbiomes of US, European, and South American facilities.
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44
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Schwendner P, Moissl-Eichinger C, Barczyk S, Bohmeier M, Pukall R, Rettberg P. Insights into the microbial diversity and bioburden in a South American spacecraft assembly clean room. ASTROBIOLOGY 2013; 13:1140-54. [PMID: 24341458 DOI: 10.1089/ast.2013.1023] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
In this study, samples from the spacecraft assembly clean room BAF (final assembly building), located at Centre Spatial Guyanais in Kourou, French Guiana, were characterized by qualitative and quantitative methods to determine the bioburden and biodiversity. The cultivation assays mainly focused on extremotolerant microorganisms that have special metabolic skills, such as the ability to grow without oxygen, fix nitrogen, grow autotrophically, or reduce sulfate. A broad range of media and growth conditions were used to simulate possible extraterrestrial environments and clean room buildings. In addition to these alternative cultivation assays, the ESA standard protocol for bioburden estimation was also applied. The phylogenetic analysis of the isolates (mainly facultative anaerobes) showed an extraordinarily broad cultivable biodiversity. Overall, 49 species were isolated and identified as members of the bacterial phyla Actinobacteria, Firmicutes, α-, β-, γ-Proteobacteria, and Bacteroidetes/Chlorobi. In addition to cultivation-based analyses, molecular techniques were also applied, including construction of a 16S rRNA gene clone library. The results indicate a wide-ranging microbial diversity (12 bacterial phyla, 34 families) that not only confirms the results of the cultivation efforts but also deepens our understanding of the noncultivable variety. Our investigations hint at a very broad, mainly uncultivated microbial diversity.
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Affiliation(s)
- Petra Schwendner
- 1 Institute of Microbiology and Archaea Center, University of Regensburg , Regensburg, Germany
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45
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Vaishampayan P, Moissl-Eichinger C, Pukall R, Schumann P, Spröer C, Augustus A, Roberts AH, Namba G, Cisneros J, Salmassi T, Venkateswaran K. Description of Tersicoccus phoenicis gen. nov., sp. nov. isolated from spacecraft assembly clean room environments. Int J Syst Evol Microbiol 2013; 63:2463-2471. [DOI: 10.1099/ijs.0.047134-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Two strains of aerobic, non-motile, Gram-reaction-positive cocci were independently isolated from geographically distinct spacecraft assembly clean room facilities (Kennedy Space Center, Florida, USA and Centre Spatial Guyanais, Kourou, French Guiana). A polyphasic study was carried out to delineate the taxonomic identity of these two isolates (1P05MAT and KO_PS43). The 16S rRNA gene sequences exhibited a high similarity when compared to each other (100 %) and lower than 96.7 % relatedness with
Arthrobacter crystallopoietes
ATCC 15481T,
Arthrobacter luteolus
ATCC BAA-272T,
Arthrobacter tumbae
DSM 16406T and
Arthrobacter subterraneus
DSM 17585T. In contrast with previously described
Arthrobacter
species, the novel isolates maintained their coccidal morphology throughout their growth and did not exhibit the rod–coccus life cycle typically observed in nearly all
Arthrobacter
species, except
A. agilis
. The distinct taxonomic identity of the novel isolates was confirmed based on their unique cell-wall peptidoglycan type (A.11.20; Lys-Ser-Ala2) and polar lipid profile (presence of phosphatidylglycerol, diphosphatidylglycerol, phosphatidylinositol, an unknown phospholipid and two unknown glycolipids). The G+C content of the genomic DNA was 70.6 mol%. The novel strains revealed MK-9(H2) and MK-8(H2) as dominant menaquinones and exhibited fatty acid profiles consisting of major amounts of anteiso-C15 : 0 and anteiso-C17 : 0 and moderate amounts of iso-C15 : 0 discriminating them again from closely related
Arthrobacter
species. Based on these observations, the authors propose that strains 1P05MAT and KO_PS43 be assigned into a separate genus Tersicoccus gen. nov. For this new taxon, comprising strains 1P05MAT and KO_PS43, we propose the name Tersicoccus phoenicis gen. nov., sp. nov. (the type species of Tersicoccus), represented by the type strain Tersicoccus phoenicis 1P05MAT ( = NRRL B-59547T = DSM 30849T).
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Affiliation(s)
- Parag Vaishampayan
- Biotechnology and Planetary Protection Group, Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA
| | - Christine Moissl-Eichinger
- Institute for Microbiology and Archaea Center, University of Regensburg, Universitaetsstr. 31, 93053 Regensburg, Germany
| | - Rüdiger Pukall
- Leibniz-Institute DSMZ – German Collection of Microorganisms and Cell Cultures, Inhoffenstr. 7B, D-38124 Braunschweig, Germany
| | - Peter Schumann
- Leibniz-Institute DSMZ – German Collection of Microorganisms and Cell Cultures, Inhoffenstr. 7B, D-38124 Braunschweig, Germany
| | - Cathrin Spröer
- Leibniz-Institute DSMZ – German Collection of Microorganisms and Cell Cultures, Inhoffenstr. 7B, D-38124 Braunschweig, Germany
| | - Angela Augustus
- Department of Biological Sciences, California State University Los Angeles, Los Angeles, CA 90032, USA
| | - Anne Hayden Roberts
- Department of Biological Sciences, California State University Los Angeles, Los Angeles, CA 90032, USA
| | - Greg Namba
- Department of Biological Sciences, California State University Los Angeles, Los Angeles, CA 90032, USA
| | - Jessica Cisneros
- Department of Biological Sciences, California State University Los Angeles, Los Angeles, CA 90032, USA
| | - Tina Salmassi
- Department of Biological Sciences, California State University Los Angeles, Los Angeles, CA 90032, USA
| | - Kasthuri Venkateswaran
- Biotechnology and Planetary Protection Group, Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA
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Grostern A, Alvarez-Cohen L. RubisCO-based CO2 fixation and C1 metabolism in the actinobacterium Pseudonocardia dioxanivorans CB1190. Environ Microbiol 2013; 15:3040-53. [PMID: 23663433 DOI: 10.1111/1462-2920.12144] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2013] [Accepted: 04/12/2013] [Indexed: 01/01/2023]
Abstract
Pseudonocardia is an actinobacterial genus of interest due to its potential biotechnological, medical and environmental remediation applications, as well as for the ecologically relevant symbiotic relationships it forms with attine ants. Some Pseudonocardia spp. can grow autotrophically, but the genetic basis of this capability has not previously been reported. In this study, we examined autotrophy in Pseudonocardia dioxanivorans CB1190, which can grow using H2 and CO2, as well as heterotrophically. Genomic and transcriptomic analysis of CB1190 cells grown with H2/bicarbonate implicated the Calvin-Benson-Bassham (CBB) cycle in growth-supporting CO2 fixation, as well as a [NiFe] hydrogenase-encoding gene cluster in H2 oxidation. The CBB cycle genes are evolutionarily most related to actinobacterial homologues, although synteny has not been maintained. Ribulose-1,5-bisphosphate carboxylase activity was confirmed in H2/bicarbonate-grown CB1190 cells and was detected in cells grown with the C1 compounds formate, methanol and carbon monoxide. We also demonstrated the upregulation of CBB cycle genes upon exposure of CB1190 to these C1 substrates, and identified genes putatively involved in generating CO2 from the C1 substrates by using RT-qPCR. Finally, the potential for autotrophic growth of other Pseudonocardia spp. was explored, and the ecological implications of autotrophy in attine ant- and plant root-associated Pseudonocardia discussed.
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Affiliation(s)
- Ariel Grostern
- Department of Civil and Environmental Engineering, UC Berkeley, Berkeley, CA, USA.
| | - Lisa Alvarez-Cohen
- Department of Civil and Environmental Engineering, UC Berkeley, Berkeley, CA, USA.,Earth Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
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Moissl-Eichinger C, Rettberg P, Pukall R. The first collection of spacecraft-associated microorganisms: a public source for extremotolerant microorganisms from spacecraft assembly clean rooms. ASTROBIOLOGY 2012; 12:1024-34. [PMID: 23121015 DOI: 10.1089/ast.2012.0906] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
For several reasons, spacecraft are constructed in so-called clean rooms. Particles could affect the function of spacecraft instruments, and for missions under planetary protection limitations, the biological contamination has to be restricted as much as possible. The proper maintenance of clean rooms includes, for instance, constant control of humidity and temperature, air filtering, and cleaning (disinfection) of the surfaces. The combination of these conditions creates an artificial, extreme biotope for microbial survival specialists: spore formers, autotrophs, multi-resistant, facultative, or even strictly anaerobic microorganisms have been detected in clean room habitats. Based on a diversity study of European and South-American spacecraft assembly clean rooms, the European Space Agency (ESA) has initialized and funded the creation of a public library of microbial isolates. Isolates from three different European clean rooms, as well as from the final assembly and launch facility in Kourou (French Guiana), have been phylogenetically analyzed and were lyophilized for long-term storage at the German Culture Collection facilities in Brunswick, Germany (Leibniz-Institut DSMZ-Deutsche Sammlung von Mikroorganismen und Zellkulturen). The isolates were obtained by either following the standard protocol for the determination of bioburden on, and around, spacecraft or the use of alternative cultivation strategies. Currently, the database contains 298 bacterial strains. Fifty-nine strains are Gram-negative microorganisms, belonging to the α-, β- and γ-Proteobacteria. Representatives of the Gram-positive phyla Actinobacteria, Bacteroidetes/Chlorobi, and Firmicutes were subjected to the collection. Ninety-four isolates (21 different species) of the genus Bacillus were included in the ESA collection. This public collection of extremotolerant microbes, which are adapted to a complicated artificial biotope, provides a wonderful source for industry and research focused on very unusual properties of microbes. For ESA, this collection is an essential resource with which to evaluate the contamination potential of spacecraft-associated biology and validate new biological contamination control and reduction procedures.
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Stieglmeier M, Rettberg P, Barczyk S, Bohmeier M, Pukall R, Wirth R, Moissl-Eichinger C. Abundance and diversity of microbial inhabitants in European spacecraft-associated clean rooms. ASTROBIOLOGY 2012; 12:572-85. [PMID: 22794299 DOI: 10.1089/ast.2011.0735] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
The determination of the microbial load of a spacecraft en route to interesting extraterrestrial environments is mandatory and currently based on the culturable, heat-shock-surviving portion of microbial contaminants. Our study compared these classical bioburden measurements as required by NASA's and ESA's guidelines for the microbial examination of flight hardware, with molecular analysis methods (16S rRNA gene cloning and quantitative PCR) to further develop our understanding of the diversity and abundance of the microbial communities of spacecraft-associated clean rooms. Three samplings of the Herschel Space Observatory and its surrounding clean rooms were performed in two different European facilities. Molecular analyses detected a broad diversity of microbes typically found in the human microbiome with three bacterial genera (Staphylococcus, Propionibacterium, and Brevundimonas) common to all three locations. Bioburden measurements revealed a low, but heterogeneous, abundance of spore-forming and other heat-resistant microorganisms. Total cell numbers estimated by quantitative real-time PCR were typically 3 orders of magnitude greater than those determined by viable counts, which indicates a tendency for traditional methods to underestimate the extent of clean room bioburden. Furthermore, the molecular methods allowed the detection of a much broader diversity than traditional culture-based methods.
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Horneck G, Moeller R, Cadet J, Douki T, Mancinelli RL, Nicholson WL, Panitz C, Rabbow E, Rettberg P, Spry A, Stackebrandt E, Vaishampayan P, Venkateswaran KJ. Resistance of bacterial endospores to outer space for planetary protection purposes--experiment PROTECT of the EXPOSE-E mission. ASTROBIOLOGY 2012; 12:445-56. [PMID: 22680691 PMCID: PMC3371261 DOI: 10.1089/ast.2011.0737] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Spore-forming bacteria are of particular concern in the context of planetary protection because their tough endospores may withstand certain sterilization procedures as well as the harsh environments of outer space or planetary surfaces. To test their hardiness on a hypothetical mission to Mars, spores of Bacillus subtilis 168 and Bacillus pumilus SAFR-032 were exposed for 1.5 years to selected parameters of space in the experiment PROTECT during the EXPOSE-E mission on board the International Space Station. Mounted as dry layers on spacecraft-qualified aluminum coupons, the "trip to Mars" spores experienced space vacuum, cosmic and extraterrestrial solar radiation, and temperature fluctuations, whereas the "stay on Mars" spores were subjected to a simulated martian environment that included atmospheric pressure and composition, and UV and cosmic radiation. The survival of spores from both assays was determined after retrieval. It was clearly shown that solar extraterrestrial UV radiation (λ≥110 nm) as well as the martian UV spectrum (λ≥200 nm) was the most deleterious factor applied; in some samples only a few survivors were recovered from spores exposed in monolayers. Spores in multilayers survived better by several orders of magnitude. All other environmental parameters encountered by the "trip to Mars" or "stay on Mars" spores did little harm to the spores, which showed about 50% survival or more. The data demonstrate the high chance of survival of spores on a Mars mission, if protected against solar irradiation. These results will have implications for planetary protection considerations.
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Affiliation(s)
- Gerda Horneck
- Radiation Biology Department, Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, Germany.
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Low-temperature decontamination with hydrogen peroxide or chlorine dioxide for space applications. Appl Environ Microbiol 2012; 78:4169-74. [PMID: 22492450 DOI: 10.1128/aem.07948-11] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The currently used microbial decontamination method for spacecraft and components uses dry-heat microbial reduction at temperatures of >110°C for extended periods to prevent the contamination of extraplanetary destinations. This process is effective and reproducible, but it is also long and costly and precludes the use of heat-labile materials. The need for an alternative to dry-heat microbial reduction has been identified by space agencies. Investigations assessing the biological efficacy of two gaseous decontamination technologies, vapor hydrogen peroxide (Steris) and chlorine dioxide (ClorDiSys), were undertaken in a 20-m(3) exposure chamber. Five spore-forming Bacillus spp. were exposed on stainless steel coupons to vaporized hydrogen peroxide and chlorine dioxide gas. Exposure for 20 min to vapor hydrogen peroxide resulted in 6- and 5-log reductions in the recovery of Bacillus atrophaeus and Geobacillus stearothermophilus, respectively. However, in comparison, chlorine dioxide required an exposure period of 60 min to reduce both B. atrophaeus and G. stearothermophilus by 5 logs. Of the three other Bacillus spp. tested, Bacillus thuringiensis proved the most resistant to hydrogen peroxide and chlorine dioxide with D values of 175.4 s and 6.6 h, respectively. Both low-temperature decontamination technologies proved effective at reducing the Bacillus spp. tested within the exposure ranges by over 5 logs, with the exception of B. thuringiensis, which was more resistant to both technologies. These results indicate that a review of the indicator organism choice and loading could provide a more appropriate and realistic challenge for the sterilization procedures used in the space industry.
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