Effects of yeast immobilization on bioethanol production

Abstract

The current study evaluated a newer method, which includes a dehydration step, of immobilizing Saccharomyces cerevisiae L-77 and S. cerevisiae L-73 onto hydroxylapatite and chamotte ceramic supports. The efficiency of cell immobilization on chamotte was significantly higher than hydroxylapatite. Immobilized yeast preparations were investigated for their ethanol-producing capabilities. The glucose concentration in a fermentation medium was 100 mg/mL. Immobilized preparations produced the same amount of ethanol (48 ± 0.5 mg/mL) as free cells after 36 H of fermentation. During the early stages of fermentation, immobilized yeast cells produced ethanol at a higher rate than free cells. Yeast preparations immobilized on both supports (hydroxylapatite and chamotte) were successfully used in six sequential batch fermentations without any loss of activity. The chamotte support was more stable in the fermentation medium during these six cycles of ethanol production. In addition to the high level of ethanol produced by cells immobilized on chamotte, the stability of this support and its low cost make it a promising material for biotechnologies associated with ethanol production.

Immobilization of Clostridium acetobutylicum onto natural textiles and its fermentation properties

“…In cell-immobilized fermentation, cells are physically confined or localized to a certain area to preserve some desired catalytic activity (Goulter et al, 2010;Choi et al, 2015). This process involves four steps: (i) attachment or adsorption, (ii) entrapment, (iii) aggregation by self or with cross-linking agents, and (iv) cell containment behind barriers (Pilkington et al, 1998;Kourkoutas et al, 2004;Borovikova et al, 2014;Zhuang et al, 2016a). Optimization of methods and support materials are important for cell immobilization; for example, the geometrical structure and surface chemistry of the support carriers directly influence microbial adhesion (Beshay and Moreira, 2003;Kourkoutas et al, 2005;Teughels et al, 2006;Dolej s et al, 2014).…”

Immobilization of Saccharomyces cerevisiae using polyethyleneimine grafted collagen fibre as support and investigations of its fermentation performance

“…[1][2][3]. Cell immobilization by adsorption is often preferred for ethanol fermentation because of its simplicity, low cost and high efficiency [4]. Moreover, the adsorption technique permits sufficient diffusion of nutrients and metabolites, and especially leads to easy evolution of CO 2 during fermentation [5][6][7].…”

Enhancing microbial production of biofuels by expanding microbial metabolic pathways

“…Biofuels can be produced by oleaginous microorganisms, such as yeast, fungi, and bacteria . Traditional microbial strains for industrial applications have been developed by random mutagenesis and screening processes .…”