Dr Cristian Varela
Lecturer
School of Agriculture, Food and Wine
Faculty of Sciences, Engineering and Technology
Eligible to supervise Masters and PhD - email supervisor to discuss availability.
Dr Cristian Varela has 20 years of research experience in academia and the private sector having worked in Australia, Chile, South Africa, France and Canada in the fields of microbiology, bioprocess engineering, fermentation technologies, systems biology and sensory analysis.
Past research activities include the development and characterisation of yeast strains to produce reduced-alcohol wines, evaluation of the effect of different environmental conditions, such as temperature and nutrient availability, on yeast metabolism and wine flavour and aroma; and the evaluation of gene modification techniques to shift yeast metabolism away from ethanol production. Dr Varela is recently interested in applying this knowledge in new areas within the food industry including coffee production, cacao (chocolate), brewing, distilling and kombucha.
Dr Varela has coordinated and delivered workshops to wine industry members throughout Australia (Hunter Valley, McClaren Vale, Barossa Valley, Riverland, other) disseminating information on novel fermentation approaches aimed at decreasing alcohol concentration in wine.
Dr Varela is member of editorial boards for peer-review journals: Applied and Environmental Microbiology; International Journal of Food Microbiology; and Food Microbiology. Reviewer for more than 20 peer-reviewed journals.
Evaluator for grant-awarding bodies, including: ERANET (ERASYSAPP, Europe-wide initiative for Applied Systems Biology); FWO (Research Foundation Flanders); CONICYT (National Commission for Scientific and Technological Research, Chile).
Recipient of Endeavour Award Fellowship in 2015. Four months of research as a visiting scientist at the Donnelly Centre for Cellular and Biomolecular Research at the University of Toronto.
Media interviews for magazines/journals including Scientific American, Wine Spectator, Wine-Searcher, Microbe magazine, The Australian & New Zealand Grapegrower & Winemaker.
My research interests include:
- Investigating and reporting the microbial populations associated with the fermentation of Australian aboriginal beverages. This included way-a-linah made from sap from the cider gum, a Eucalyptus tree native to the remote Central Highlands of Tasmania, and the yeast microbiota associated with flowers, fruits and palm trees from Erub Island in the Torres Strait.
- Bioprospecting thousands of individual yeast isolates from grape must, determining their taxonomy, and evaluating their phenotype with the aim of providing novel yeast starter cultures for winemaking.
- Evaluating the effect of winemaking interventions, including sulfur dioxide addition, aeration and fermentation temperature, on yeast population dynamics during un-inoculated wine fermentations.
- Characterising Brettanomyces bruxellensis industry isolates and developing molecular tools to genetically modify this species.
- Development of a Systems Biology approach to study wine yeast fermentation.
- Evaluation of the ability of wine spoilage microorganisms to increase their tolerance to antimicrobial agents.
Recent funding awarded for a collaborative research project between the University of Adelaide and the Australian Wine Research Institute to characterise the microbial communities associated with coffee fermentation in Australia. This research will be commencing in the coming months.
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Appointments
Date Position Institution name 2023 - ongoing Lecturer University of Adelaide 2019 - 2023 Principal Research Scientist Australian Wine Research Institute 2010 - 2019 Senior Research Scientist Australian Wine Research Institute 2005 - 2010 Research Microbiologist Australian Wine Research Institute 2004 - 2005 Postdoctoral Research Fellow Australian Wine Research Institute -
Awards and Achievements
Date Type Title Institution Name Country Amount 2015 Award Endeavour Award Fellowship Australian Wine Research Institute Australia - -
Language Competencies
Language Competency Spanish - Latin American Can read, write, speak, understand spoken and peer review -
Education
Date Institution name Country Title 1999 - 2004 Pontifical Catholic University of Chile Chile PhD 1996 - 1998 Pontifical Catholic University of Chile Chile MSc 1992 - 1995 Pontifical Catholic University of Chile Chile Bachelor -
Research Interests
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Journals
Year Citation 2024 Villarreal, P., O'Donnell, S., Agier, N., Muñoz-Guzman, F., Benavides-Parra, J., Urbina, K., . . . Cubillos, F. A. (2024). Domestication signatures in the non-conventional yeast Lachancea cidri. mSystems, 9(1), e0105823.
2023 Varela, C., Alperstein, L., Sundstrom, J., Solomon, M., Brady, M., Borneman, A., & Jiranek, V. (2023). A special drop: Characterising yeast isolates associated with fermented beverages produced by Australia's indigenous peoples. Food Microbiology, 112, 104216-1-104216-11.
Scopus1 Europe PMC12022 Villarreal, P., Villarroel, C. A., O'Donnell, S., Agier, N., Quintero-Galvis, J. F., Peña, T. A., . . . Cubillos, F. A. (2022). Late Pleistocene-dated divergence between South Hemisphere populations of the non-conventional yeast L. cidri. Environmental Microbiology, 24(12), 5615-5629.
Scopus1 Europe PMC12022 Varela, C. (2022). KU80 deletion does not improve homologous recombination in Brettanomyces bruxellensis.
2022 Varela, C., & Borneman, A. R. (2022). Molecular approaches improving our understanding of Brettanomyces physiology. FEMS YEAST RESEARCH, 22(1), 1-15.
Scopus1 WoS12021 Varela, C., Bartel, C., Espinase Nandorfy, D., Bilogrevic, E., Tran, T., Heinrich, A., . . . Borneman, A. (2021). Volatile aroma composition and sensory profile of Shiraz and Cabernet Sauvignon wines produced with novel Metschnikowia pulcherrima yeast starter cultures. Australian Journal of Grape and Wine Research, 27(3), 406-418.
Scopus12 WoS72021 Varela, C., Cuijvers, K., Van Den Heuvel, S., Rullo, M., Solomon, M., Borneman, A., & Schmidt, S. (2021). Effect of Aeration on Yeast Community Structure and Volatile Composition in Uninoculated Chardonnay Wines. Fermentation, 7(2), 1-17.
Scopus8 WoS72021 Bartel, C., Roach, M., Onetto, C., Curtin, C., Varela, C., & Borneman, A. (2021). Adaptive evolution of sulfite tolerance in Brettanomyces bruxellensis. FEMS Yeast Research, 21(5), 1-12.
Scopus6 WoS4 Europe PMC22021 Varela, C., Cuijvers, K., & Borneman, A. (2021). Temporal comparison of microbial community structure in an australian winery. Fermentation, 7(3), 15 pages.
Scopus2 WoS22020 Varela, C., Bartel, C., Nandorfy, D. E., Borneman, A., Schmidt, S., & Curtin, C. (2020). Identification of flocculant wine yeast strains with improved filtration-related phenotypes through application of high-throughput sedimentation rate assays. Scientific Reports, 10(1), 1-13.
Scopus6 WoS6 Europe PMC22020 Varela, C., Bartel, C., Onetto, C., & Borneman, A. (2020). Targeted gene deletion in Brettanomyces bruxellensis with an expression-free CRISPR-Cas9 system.. Applied Microbiology and Biotechnology, 104(16), 7105-7115.
Scopus9 WoS8 Europe PMC12020 Varela, C., Sundstrom, J., Cuijvers, K., Jiranek, V., & Borneman, A. (2020). Discovering the indigenous microbial communities associated with the natural fermentation of sap from the cider gum Eucalyptus gunnii. Scientific Reports, 10(1), 14716-1-14716-13.
Scopus12 WoS10 Europe PMC42020 Cuijvers, K., van Den Heuvel, S., Varela, C., Rullo, M., Solomon, M., Schmidt, S., & Borneman, A. (2020). Alterations in yeast species composition of uninoculated wine ferments by the addition of sulphur dioxide. Fermentation, 6(2), 1-13.
Scopus5 WoS52019 Canonico, L., Solomon, M., Comitini, F., Ciani, M., & Varela, C. (2019). Volatile profile of reduced alcohol wines fermented with selected non-Saccharomyces yeasts under different aeration conditions. Food Microbiology, 84, 1-8.
Scopus68 WoS58 Europe PMC202019 Avramova, M., Grbin, P., Borneman, A., Albertin, W., Masneuf-Pomarède, I., & Varela, C. (2019). Competition experiments between Brettanomyces bruxellensis strains reveal specific adaptation to sulfur dioxide and complex interactions at intraspecies level.. FEMS yeast research, 19(3), 9 pages.
Scopus13 WoS12 Europe PMC52019 Varela, C., Bartel1, C., Roach, M., Borneman1, A., & Curtin, C. (2019). Brettanomyces bruxellensis SSU1 haplotypes confer different levels of sulfite tolerance when expressed in a Saccharomyces cerevisiae SSU1 null mutant. Applied and Environmental Microbiology, 85(4), 16 pages.
Scopus17 WoS15 Europe PMC62019 Varela, J., & Varela, C. (2019). Microbiological strategies to produce beer and wine with reduced ethanol concentration. Current Opinion in Biotechnology, 56, 88-96.
Scopus45 WoS40 Europe PMC152018 Varela, C., Lleixà, J., Curtin, C., & Borneman, A. (2018). Development of a genetic transformation toolkit for Brettanomyces bruxellensis. FEMS yeast research, 18(7), 1-6.
Scopus9 WoS9 Europe PMC42018 Varela, C., Schmidt, S. A., Borneman, A. R., Pang, C. N. I., Krömerx, J. O., Khan, A., . . . Chambers, P. J. (2018). Systems-based approaches enable identification of gene targets which improve the flavour profile of low-ethanol wine yeast strains. Metabolic Engineering, 49, 178-191.
Scopus16 WoS12 Europe PMC82017 Varela, C., Barker, A., Tran, T., Borneman, A., & Curtin, C. (2017). Sensory profile and volatile aroma composition of reduced alcohol Merlot wines fermented with Metschnikowia pulcherrima and Saccharomyces uvarum. International Journal of Food Microbiology, 252, 1-9.
Scopus98 WoS80 Europe PMC292017 Varela, C., & Borneman, A. R. (2017). Yeasts found in vineyards and wineries. Yeast, 34(3), 111-128.
Scopus107 WoS93 Europe PMC452017 Goold, H. D., Kroukamp, H., Williams, T. C., Paulsen, I. T., Varela, C., & Pretorius, I. S. (2017). Yeast's balancing act between ethanol and glycerol production in low-alcohol wines. Microbial Biotechnology, 10(2), 264-278.
Scopus111 WoS98 Europe PMC362016 Varela, C. (2016). The impact of non-Saccharomyces yeasts in the production of alcoholic beverages. Applied Microbiology and Biotechnology, 100(23), 9861-9874.
Scopus183 WoS160 Europe PMC592016 Varela, C., Sengler, F., Solomon, M., & Curtin, C. (2016). Volatile flavour profile of reduced alcohol wines fermented with the non-conventional yeast species Metschnikowia pulcherrima and Saccharomyces uvarum. Food Chemistry, 209, 57-64.
Scopus124 WoS97 Europe PMC402015 Contreras, A., Curtin, C., & Varela, C. (2015). Yeast population dynamics reveal a potential ‘collaboration’ between Metschnikowia pulcherrima and Saccharomyces uvarum for the production of reduced alcohol wines during Shiraz fermentation. Applied Microbiology and Biotechnology, 99(4), 1885-1895.
Scopus94 WoS81 Europe PMC372015 Chambers, P. J., Borneman, A. R., Varela, C., Cordente, A. G., Bellon, J. R., Tran, T. M. T., . . . Curtin, C. D. (2015). Ongoing domestication of wine yeast: Past, present and future. Australian Journal of Grape and Wine Research, 21, 642-650.
Scopus15 WoS132015 Curtin, C., Varela, C., & Borneman, A. (2015). Harnessing improved understanding of Brettanomyces bruxellensis biology to mitigate the risk of wine spoilage. Australian Journal of Grape and Wine Research, 21, 680-692.
Scopus24 WoS222015 Contreras, A., Hidalgo, C., Schmidt, S., Henschke, P., Curtin, C., & Varela, C. (2015). The application of non-Saccharomyces yeast in fermentations with limited aeration as a strategy for the production of wine with reduced alcohol content. International Journal of Food Microbiology, 205, 7-15.
Scopus148 WoS127 Europe PMC492015 Varela, C., Dry, P., Kutyna, D., Francis, I., Henschke, P., Curtin, C., & Chambers, P. (2015). Strategies for reducing alcohol concentration in wine. Australian Journal of Grape and Wine Research, 21(Suppl. 1), 670-679.
Scopus99 WoS852014 Jolly, N., Varela, C., & Pretorius, I. (2014). Not your ordinary yeast: non-Saccharomyces yeasts in wine production uncovered. FEMS Yeast Research, 14(2), 215-237.
Scopus643 WoS559 Europe PMC2392014 Contreras, A., Hidalgo, C., Henschke, P., Chambers, P., Curtin, C., & Varela, C. (2014). Evaluation of non-Saccharomyces yeasts for the reduction of alcohol content in wine. Applied and Environmental Microbiology, 80(5), 1670-1678.
Scopus274 WoS224 Europe PMC912014 Bindon, K., Holt, H., Williamson, P., Varela, C., Herderich, M., & Francis, I. (2014). Relationships between harvest time and wine composition in Vitis vinifera L. cv. Cabernet Sauvignon 2. Wine sensory properties and consumer preference. Food Chemistry, 154, 90-101.
Scopus93 WoS85 Europe PMC182014 Kutyna, D. R., Cordente, A. G., & Varela, C. (2014). Genetic Engineering of Industrial Saccharomycescerevisiae Strains Using a Selection/Counter-selection Approach. Methods in Molecular Biology, 1152, 157-168.
Scopus6 Europe PMC22013 Schmidt, S. A., Jacob, S. S., Ahn, S. B., Rupasinghe, T., Krömer, J. O., Khan, A., & Varela, C. (2013). Two strings to the systems biology bow: Co-extracting the metabolome and proteome of yeast. Metabolomics, 9(1), 173-188.
Scopus14 WoS112013 Krömer, J. O., Nunez-Bernal, D., Averesch, N. J. H., Hampe, J., Varela, J., & Varela, C. (2013). Production of aromatics in Saccharomyces cerevisiae-A feasibility study. Journal of Biotechnology, 163(2), 184-193.
Scopus59 WoS53 Europe PMC372013 Bindon, K., Varela, C., Kennedy, J., Holt, H., & Herderich, M. (2013). Relationships between harvest time and wine composition in Vitis vinifera L. cv. Cabernet Sauvignon 1. Grape and wine chemistry. Food Chemistry, 138(2-3), 1696-1705.
Scopus163 WoS151 Europe PMC372013 Bindon, K., Varela, C., Kennedy, J., Holt, H., & Herderich, M. (2013). Erratum: Relationships between harvest time and wine composition in Vitis vinifera L. cv. Cabernet Sauvignon 1. Grape and wine chemistry (Food Chemistry (2013) 138 (1696-1705) DOI:10.1016/j.foodchem.2012.09.146). Food Chemistry, 141(1), 147.
Scopus6 WoS32012 Kutyna, D. R., Varela, C., Stanley, G. A., Borneman, A. R., Henschke, P. A., & Chambers, P. J. (2012). Adaptive evolution of Saccharomyces cerevisiae to generate strains with enhanced glycerol production. Applied Microbiology and Biotechnology, 93(3), 1175-1184.
Scopus71 WoS62 Europe PMC382012 Cordente, A., Curtin, C., Varela, C., & Pretorius, I. (2012). Flavour-active wine yeasts. Applied Microbiology and Biotechnology, 96(3), 601-618.
Scopus119 WoS105 Europe PMC442012 Varela, C., Kutyna, D., Solomon, M., Black, C., Borneman, A., Henschke, P., . . . Chambers, P. (2012). Evaluation of gene modification strategies for the development of low-alcohol-wine yeasts. Applied and Environmental Microbiology, 78(17), 6068-6077.
Scopus82 WoS74 Europe PMC392012 Vilanova, M., Siebert, T., Varela, C., Pretorius, I., & Henschke, P. (2012). Effect of ammonium nitrogen supplementation of grape juice on wine volatiles and non-volatiles composition of the aromatic grape variety Albariño. Food Chemistry, 133(1), 124-131.
Scopus64 WoS57 Europe PMC72012 Varela, C., Torrea, D., Schmidt, S., Ancin-Azpilicueta, C., & Henschke, P. (2012). Effect of oxygen and lipid supplementation on the volatile composition of chemically defined medium and Chardonnay wine fermented with Saccharomyces cerevisiae. Food Chemistry, 135(4), 2863-2871.
Scopus92 WoS83 Europe PMC142011 Torrea, D., Varela, C., Ugliano, M., Ancin-Azpilicueta, C., Leigh Francis, I., & Henschke, P. (2011). Comparison of inorganic and organic nitrogen supplementation of grape juice - Effect on volatile composition and aroma profile of a Chardonnay wine fermented with Saccharomyces cerevisiae yeast. Food Chemistry, 127(3), 1072-1083.
Scopus143 WoS127 Europe PMC162011 Varela, C., Schmidt, S. A., Borneman, A. R., Kromer, J. O., Khan, A., & Chambers, P. J. (2011). Systems biology: a new paradigm for industrial yeast strain development. MICROBIOLOGY AUSTRALIA, 32(4), 151-155. 2010 Kutyna, D. R., Varela, C., Henschke, P. A., Chambers, P. J., & Stanley, G. A. (2010). Microbiological approaches to lowering ethanol concentration in wine. Trends in Food Science and Technology, 21(6), 293-302.
Scopus107 WoS97 Europe PMC302009 Varela, C., Siebert, T., Cozzolino, D., Rose, L., McLean, H., & Henschke, P. A. (2009). Discovering a chemical basis for differentiating wines made by fermentation with 'wild' indigenous and inoculated yeasts: role of yeast volatile compounds. Australian Journal of Grape and Wine Research, 15(3), 238-248.
Scopus70 WoS602009 Molina, A., Guadalupe, V., Varela, C., Swiegers, J., Pretorius, I., & Agosin, E. (2009). Differential synthesis of fermentative aroma compounds of two related commercial wine yeast strains. Food Chemistry, 117(2), 189-195.
Scopus99 WoS76 Europe PMC172007 Vilanova, M., Ugliano, M., Varela, C., Siebert, T., Pretorius, I., & Henschke, P. (2007). Assimilable nitrogen utilisation and production of volatile and non-volatile compounds in chemically defined medium by Saccharomyces cerevisiae wine yeasts. Applied Microbiology and Biotechnology, 77(1), 145-157.
Scopus205 WoS194 Europe PMC672007 Bartowsky, E., Bellon, J., Borneman, A., Chambers, P., Cordente, A., Costello, P., . . . Pretorius, S. (2007). Not all wine yeast are equal. MICROBIOLOGY AUSTRALIA, 28(2), 55-58.
WoS42007 Pizarro, F., Varela, C., Martabit, C., Bruno, C., Pérez-Correa, J. R., & Agosin, E. (2007). Coupling kinetic expressions and metabolic networks for predicting wine fermentations. Biotechnology and Bioengineering, 98(5), 986-998.
Scopus36 WoS28 Europe PMC162007 Molina, A. M., Swiegers, J. H., Varela, C., Pretorius, I. S., & Agosin, E. (2007). Influence of wine fermentation temperature on the synthesis of yeast-derived volatile aroma compounds. Applied Microbiology and Biotechnology, 77(3), 675-687.
Scopus231 WoS190 Europe PMC742006 Malig, R., Varela, C., Agosin, E., & Melo, F. (2006). Accurate and unambiguous tag-to-gene mapping in serial analysis of gene expression. BMC Bioinformatics, 7(1), 17 pages.
Scopus8 WoS7 Europe PMC92005 Varela, C., Cárdenas, J., Melo, F., & Agosin, E. (2005). Quantitative analysis of wine yeast gene expression profiles under winemaking conditions. Yeast, 22(5), 369-383.
Scopus93 WoS90 Europe PMC582004 Varela, C. A., Baez, M. E., & Agosin, E. (2004). Osmotic stress response: Quantification of cell maintenance and metabolic fluxes in a lysine-overproducing strain of Corynebacterium glutamicum. Applied and Environmental Microbiology, 70(7), 4222-4229.
Scopus38 WoS37 Europe PMC242004 Varela, C., Pizarro, F., & Agosin, E. (2004). Biomass content governs fermentation rate in nitrogen-deficient wine musts. Applied and Environmental Microbiology, 70(6), 3392-3400.
Scopus175 WoS165 Europe PMC962003 Varela, C., Agosin, E., Baez, M., Klapa, M., & Stephanopoulos, G. (2003). Metabolic flux redistribution in Corynebacterium glutamicum in response to osmotic stress. Applied Microbiology and Biotechnology, 60(5), 547-555.
Scopus63 WoS55 Europe PMC352002 Bobadilla, R., Varela, C., Céspedes, R., & González, B. (2002). Engineering bacterial strains through the chromosomal insertion of the chlorocatechol catabolism <i>tfd</i><sub>I</sub>CDEF gene cluster, to improve degradation of typical bleached Kraft pulp mill effluent pollutants. ELECTRONIC JOURNAL OF BIOTECHNOLOGY, 5(2), 162-172.
WoS2 -
Book Chapters
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Preprint
Year Citation 2023 Villarreal, P., O’Donnell, S., Agier, N., Muñoz-Guzmán, F., Benavides-Parra, J., Urbina, K., . . . Cubillos, F. A. (2023). Domestication signatures in the non-conventional yeast<i>Lachancea cidri</i>.
2023 - 2024 Understanding how fermentation can improve the distinctiveness of Australian coffee. Dr Cristian Varela, Dr David Jeffery. Funding: UoA/AWRI.
2022 - 2023 Co-innovation project wine production and quality. Dr. Keren Bindon, Dr Cristian Varela. Funding: Wine Australia.
2022 - 2023 Impact project No and Low (NoLo) alcohol wine. Dr. Wes Pearson, Dr Josh Hixson, Dr Cristian Varela. Funding: Wine Australia.
2017 - 2022 Bioprospecting Australia’s microbial genetic diversity. Dr Anthony Borneman, Dr Cristian Varela, Kate Cuijvers, Steven Van Den Heuvel, Laura Hale, Dr Cristobal Onetto. Funding: Wine Australia.
2017 - 2022 Understanding Brettanomyces and its adaptation to control measures. Dr Anthony Borneman, Dr Cristian Varela, Kate Cuijvers, Dr Darek Kutyna, Dr Cristobal Onetto. Funding: Wine Australia.
2019 - 2020 Mapping the microbial communities associated with Hickinbotham Roseworthy Winery. Dr Cristian Varela, Dr Anthony Bornema. Funding: AWRI
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Current Higher Degree by Research Supervision (University of Adelaide)
Date Role Research Topic Program Degree Type Student Load Student Name 2023 Principal Supervisor Selection of lactic acid bacteria for efficient malolactic fermentation in the presence of sulfur dioxide Doctor of Philosophy Doctorate Full Time Ms Yingxin Liu 2023 Co-Supervisor Novel microbes from Australian plants: Characterisation and industrial potential Doctor of Philosophy Doctorate Full Time Miss Tea Knezevic -
Other Supervision Activities
Date Role Research Topic Location Program Supervision Type Student Load Student Name 2018 - 2019 Co-Supervisor Characterising Yeast from Traditional Indigenous Australian Fermentations University of Adelaide Bachelor of Science Honours Full Time Lucien Alperstein 2016 - 2017 Co-Supervisor Controlling yeast flocculation via the manipulation of yeast promoters University of Adelaide Master of Viticulture and Oenology Master Full Time Qiushuo Feng
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Committee Memberships
Date Role Committee Institution Country 2023 - ongoing Member Crush: Grape and Wine Science Symposium Organising Committee Wine Innovation Cluster Australia 2023 - ongoing Member Oeno Macrowine Scientific Committee Bordeaux KEDGE Businnes School France 2022 - ongoing Member International Specialized Symposium on Yeasts Organising Committee International Commission for Yeasts Australia 2022 - 2023 Member Crush: Grape and Wine Science Symposium Organising Committee Wine Innovation Cluster Australia -
Memberships
Date Role Membership Country 2019 - ongoing Member The Australian Society of Viticulture and Oenology Australia -
Editorial Boards
Date Role Editorial Board Name Institution Country 2019 - ongoing Board Member FEMS Yeast Research Federation of European Microbiological Societies United Kingdom 2017 - ongoing Board Member Food Microbiology Elsevier Netherlands 2016 - ongoing Board Member International Journal of Food Microbiology Elsevier Netherlands 2016 - ongoing Board Member Applied and Environmental Microbiology American Society for Microbiology United States
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