Characterisation of thermotolerant, ethanol tolerant fermentative Saccharomyces cerevisiae for ethanol production

Abstract

Of the four thermotolerant, osmotolerant, occulating yeasts (VS 1 , VS 2 , VS 3 and VS 4 ) isolated from the soil samples collected within the hot regions of Kothagudem Thermal Power Plant, located in Khammam Dt., Andhra Pradesh, India, VS 1 and VS 3 were observed as better performers. They were identi®ed as Saccharomyces cerevisiae. VS 1 and VS 3 were tested for their growth characteristics and fermentation abilities on various carbon sources including molasses at 30°C and 40°C respectively. More biomass and fermentation was observed in sucrose, fructose and glucose. Maximum amount of ethanol produced by VS 3 containing 150 (g/l) of these substrates were 74, 73, and 72 (g/l) at 30°C and 64, 61 and 63 (g/l) at 40°C respectively. With molasses containing 14% sugar, the amount of ethanol produced by VS 3 was 53.2 and 45 (g/l) at 30°C and 40°C respectively. VS 3 strain showed 12% W/V ethanol tolerance. VS 3 strain was also characterised for its ethanol producing ability using various starchy substrates in solid state and submerged fermentation. More ethanol was produced in submerged than solid state fermentation.

Estudo da fermentação do hidrolisado de batata-doce utilizando diferentes linhagens de Saccharomyces cerevisiae

“…Na fermentação submersa de diversos substratos amiláceos, Kiransree et al 15 utilizaram duas linhagens termotolerantes de S. cerevisiae para avaliar a capacidade de produção de etanol a 37 e 42 °C e notaram maior quantidade de etanol produzido na fermentação de trigo e batata-doce, nas mesmas condições que amido de arroz, de batata, sorgo doce e amido solúvel. Isto corrobora a informação de que batata-doce é um bom substrato para a produção de etanol, quando comparada a outros substratos amiláceos.…”

The Kinetics of Ethanol Production from Cane Molasses bySaccharomyces cerevisiaein a Batch Bioreactor

“…Cassava and sago starch-rich wastes from potato-processing industries were successfully used for ethanol production (Amutha and Gunasekaran, 2001;Rebroš et al, 2009); molasses from the sugar industry were assessed for ethanol production by yeast cells (Yamada et al, 2002); cheese whey wastes were found to produce better results than conventional medium for rhamnolipid production (Lucília et al, 2001;Silveira et al, 2005); and grape juice from the food industry was investigated for kinetic study of ethanol fermentation (Holzberg et al, 1967). Several microorganisms, including S. cerevisiae (Echegaray et al, 2000;Kiransree et al, 2000;Win et al, 1996), Kluyveromyces marxianus (Gough et al, 1998), and Zymomonas mobilis (Amutha and Gunasekaran, 2001;Panesar et al, 2006;Rebroš et al, 2009;Yamada et al, 2002) are the well-known ethanol producers. The yeast, S. cerevisiae, is largely employed in ethanol production using renewable biomass such as sugar cane, sugar beet and molasses as the main carbon source (Echegaray et al, 2000).…”

Genome shuffling to improve thermotolerance, ethanol tolerance and ethanol productivity of Saccharomyces cerevisiae

“…The maximum ethanol yields produced by the mutant of VS 3 strain from 250 g/l glucose were 98 and 62 g/l at 30 and 40°C, respectively. In another research, VS 3 strain was reported to show 12% (w/v) ethanol tolerance [18]. Balakumar et al [4] reported the isolation and improvement of a thermotolerant Saccharomyces cerevisiae strain.…”