Microbial evolution in the fuel ethanol industry in Brazil

• Grant number: 18/04962-5
• Support Opportunities: Scholarships abroad - Research
• Effective date (Start): January 01, 2019
• Effective date (End): December 24, 2019
• Field of knowledge: Engineering - Chemical Engineering - Chemical Process Industries
• Principal Investigator: Andreas Karoly Gombert
• Grantee: Andreas Karoly Gombert
• Host Investigator: Michael Desai
• Host Institution: Faculdade de Engenharia de Alimentos (FEA). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Research place: Harvard University, United States

Abstract

Fuel ethanol production from sugarcane in Brazil is a vigorous agricultural/industrial activity, which contributes to economic development and to mitigate climate change. In spite of decades of operation, there still is a knowledge gap concerning several aspects of the process, such as on the microorganisms that thrive in the fermentation environment. Population dynamics has been followed in different industrial units, leading to the identification, via chromosomal karyotyping, of some strains that persist and eventually dominate the ecosystem in the fermentors. On the one hand, it is still not known which traits enable these strains to persist and dominate. On the other hand, chromosomal karyotyping can be considered a coarsed-grain technique, which is often not capable of differentiating strains properly. In the present project, we propose to investigate the evolutionary processes that underlie the adaptation of Saccharomyces cerevisiae to this peculiar fermentation environment. This will be achieved by three different approaches. First, samples will be withdrawn from two industrial units along a whole sugarcane crushing season (2018). The samples will be subjected to genome sequencing and the data analyzed for phenomena such as genetic drift, allele frequency changes, gene flow, natural selection, genetic recombination, epistasis, and clonal interference, among others. By relating these results to the operation conditions, we hope to be able to understand which genes confer some S. cerevisiae strains the capacity to persist and dominate in the fermentors. In a second line of research, several strains that were sampled from the industrial fermentation environment during the past decades, a "fossil record", will have their genomes sequenced and analyzed in a similar manner. Finally, we intend to evolve a laboratory yeast strain under different industrially-relevant conditions towards an industrial phenotype, which might enable us to pinpoint which of these conditions contribute most to the selective pressure imposed during industrial fuel ethanol production. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

RACZ, HANNA VIKTORIA; MUKHTAR, FEZAN; IMRE, ALEXANDRA; RADAI, ZOLTAN; GOMBERT, ANDREAS KAROLY; RATONYI, TAMAS; NAGY, JANOS; POCSI, ISTVAN; PFLIEGLER, WALTER P.. How to characterize a strain? Clonal heterogeneity in industrial Saccharomyces influences both phenotypes and heterogeneity in phenotypes. YEAST, v. 38, n. 8, p. 453-470, AUG 2021. (18/04962-5)