Evaluation of Aerobic Propagation of Yeasts as Additional Step in Production Process of Corn Ethanol
Matheus Ribeiro Barbosa Oliveira,
Rafael Soares Douradinho,
Pietro Sica,
Layna Amorim Mota,
Alana Uchôa Pinto,
Tamires Marques Faria,
Antonio Sampaio Baptista
Affiliations
Matheus Ribeiro Barbosa Oliveira
Department of Agri-Food Industry, Food and Nutrition, College of Agriculture “Luiz de Queiroz”, University of São Paulo, Padua Dias Avenue, 11, Piracicaba 13148-900, SP, Brazil
Rafael Soares Douradinho
Department of Agri-Food Industry, Food and Nutrition, College of Agriculture “Luiz de Queiroz”, University of São Paulo, Padua Dias Avenue, 11, Piracicaba 13148-900, SP, Brazil
Pietro Sica
Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsenvej, 40, 1821 Frederiksberg, Denmark
Layna Amorim Mota
Center for Nuclear Energy in Agriculture, University of São Paulo, Centenário Avenue, 303, Piracicaba 13416-000, SP, Brazil
Alana Uchôa Pinto
Department of Agri-Food Industry, Food and Nutrition, College of Agriculture “Luiz de Queiroz”, University of São Paulo, Padua Dias Avenue, 11, Piracicaba 13148-900, SP, Brazil
Tamires Marques Faria
Department of Agri-Food Industry, Food and Nutrition, College of Agriculture “Luiz de Queiroz”, University of São Paulo, Padua Dias Avenue, 11, Piracicaba 13148-900, SP, Brazil
Antonio Sampaio Baptista
Department of Agri-Food Industry, Food and Nutrition, College of Agriculture “Luiz de Queiroz”, University of São Paulo, Padua Dias Avenue, 11, Piracicaba 13148-900, SP, Brazil
Yeast is one of the co-products of ethanol plants, which can be used as a nutritional supplement in animal feed due to its high protein content. Given the importance of yeast contribution to the nutritional properties of DDG (dried distillers’ grains), the aim of this study was to assess how different levels of aeration affect the biomass production and the quality of yeast providing new insights into yeast production, offering an alternative source of income for the corn ethanol industry. For this purpose, yeasts were grown in a fed-batch process, and different concentrations of aeration in the medium were tested, namely 0.5, 1.0, and 1.5 volume of air per volume of wort per minute (v v−1 min−1). At the end of the cellular biomass production process, yeasts grown with 0.5 (v v−1 min−1) aeration in the reactor showed higher biomass formation (19.86 g L−1), cellular yield (g g−1), and a lower formation of succinic acid (0.70 g L−1) and acetic acid (0.11 g L−1). Aeration influenced an increase of 1.0% in the protein content in yeast. In conclusion, lower levels of aeration in the yeast production process enables more efficient sugar utilization for biomass formation and is a potential strategy to increase the protein content and the commercial value of DDG.
