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(Referência obtida automaticamente do Web of Science, por meio da informação sobre o financiamento pela FAPESP e o número do processo correspondente, incluída na publicação pelos autores.)

Enrichment of a continuous culture of Saccharomyces cerevisiae with the yeast Issatchenkia orientalis in the production of ethanol at increasing temperatures

Texto completo
Autor(es):
Gallardo, J. C. M. [1] ; Souza, C. S. [2] ; Cicarelli, R. M. B. [3] ; Oliveira, K. F. [1] ; Morais, M. R. [1] ; Laluce, C. [1]
Número total de Autores: 6
Afiliação do(s) autor(es):
[1] Sao Paulo State Univ, UNESP, Inst Quim Araraquara, Dept Biochem & Technol Chem, BR-14801970 Sao Paulo - Brazil
[2] Butantan IPT, Programa Posgrad Interunidades Biotecnol USP I, Sao Paulo - Brazil
[3] Sao Paulo State Univ, UNESP, Sch Pharmaceut Sci, Dept Biol Sci, Araraquara, SP - Brazil
Número total de Afiliações: 3
Tipo de documento: Artigo Científico
Fonte: Journal of Industrial Microbiology & Biotechnology; v. 38, n. 3, p. 405-414, MAR 2011.
Citações Web of Science: 19
Resumo

A fermentation system was continuously fed with sugar-cane syrup and operated with recycling of Saccharomyces cerevisiae cells at temperatures varying from 30 to 47A degrees C. The aim of the present work was to obtain and study the colonies of isolates showing elongated cells of yeasts which were sporadically observed at the end of this continuous process. Based on a sequence of assays involving methods of classical taxonomy and RAPD-PCR, two groups of isolates showing characteristics of non-Saccharomyces yeasts were identified in the yeast population where S. cerevisiae was the dominant yeast. The largest group of non-Saccharomyces yeasts, resulting from a slow proliferation over the 2 months, reached a final level of 29.6% at the end of the process. RAPD-PCR profiles obtained for the isolates of this dominant non-Saccharomyces yeast indicated that they were isolates of Issatchenkia orientalis. Pichia membranifaciens was the only species of non-Saccharomyces yeast detected together with I. orientalis but at a very low frequency. The optimum temperature for ethanol formation shown by the isolate 195B of I. orientalis was 42A degrees C. This strain also showed a faster ethanol formation and biomass accumulation than the thermotolerant strain of S. cerevisiae used as the starter of this fermentation process. Some isolates of I. orientalis were also able to grow better at 40A degrees C than at 30A degrees C on plates containing glycerol as carbon source. Yeasts able to grow and produce ethanol at high temperatures can extend the fermentation process beyond the temperature limits tolerated by S. cerevisiae. (AU)

Processo FAPESP: 08/56587-1 - Um método microbiológico rápido para avaliar os efeitos dos níveis dos inibidores dos hidrolisados do bagaço de cana sobre a fermentação alcoólica sem a necessidade de ensaios analíticos
Beneficiário:Karen Fernanda de Oliveira
Linha de fomento: Bolsas no Brasil - Pós-Doutorado
Processo FAPESP: 08/56247-6 - Ethanol production from sugar-cane-bagasse: enzymatic pre-treatments, microbiological assays to evaluate toxicity and tolerance to hydrolysates at increasing temperatures
Beneficiário:Cecilia Laluce
Linha de fomento: Auxílio à Pesquisa - Programa BIOEN - Regular
Processo FAPESP: 05/01498-6 - Aspectos básicos e aplicados da utilização industrial de leveduras
Beneficiário:Cecilia Laluce
Linha de fomento: Auxílio à Pesquisa - Regular