A Potential of Mutant Yeast Strain for Improvement Arabica Coffee Fermentation Process

Arabica coffee is a worldwide popular beverage. Coffee fermentation is important process to enhance the coffee flavor quality. Microorganisms involved in the process are the main factor affecting coffee quality. This study aims to apply the new starter culture of Wickerhamomyces anomalus UV22-3, a UV mutant strain, for coffee fermentation and to improve arabica coffee beverage quality. The results showed that W. anomalus UV22-3 as a starter culture for coffee fermentation could enhance the coffee flavor quality compared to the control experiment (without inoculum). Fermented arabica coffee by strain UV22-3 showed a higher cupping score than wild type and a control condition with unique cupping notes. According to the flavor profile evaluated by Q-graders, the result of this sensory evaluation is 82. Microbial population in the fermentation broth was evaluated. The total yeast number was stable, while the total bacteria was higher after 24 h of strain UV22-3 fermentation. The pH value slightly decreased when the total dissolved solid increased. This research is one alternative to improve the quality of coffee in Thailand by using a novel yeast strain

Enhancing the Productivity and Stability of Superoxide Dismutase from Saccharomyces cerevisiae TBRC657 and Its Application as a Free Radical Scavenger

Superoxide dismutase (SOD) is crucial antioxidant enzyme that plays a role in protecting cells against harmful reactive oxygen species (ROS) which are generated inside cells. Due to its functionality, SOD is used in many applications. In this study, Saccharomyces cerevisiae TBRC657 was selected as the SOD producer due to its high SOD production. After investigating an optimized medium, the major components were found to be molasses and yeast extract, which improved SOD production up to 3.97-fold compared to a synthetic medium. In addition, the optimized medium did not require any induction, which makes it suitable for applications in large-scale production. The SOD formulation was found to increase the stability of the conformational structure and prolong shelf-life. The results show that 1.0% (w/w) trehalose was the best additive, in giving the highest melting temperature by the DSF method and maintaining its activity at more than 80% after storage for 6 months. The obtained SOD was investigated for its cytotoxicity and ROS elimination against fibroblast cells. The results indicate that the SOD enhanced the proliferation and controlled ROS level inside the cells. Thus, the SOD obtained from S. cerevisiae TBRC657 cultured in the optimized medium could be a candidate for use as a ROS scavenger, which can be applied in many industries

Enhancing the Productivity and Stability of Superoxide Dismutase from <i>Saccharomyces cerevisiae</i> TBRC657 and Its Application as a Free Radical Scavenger

Superoxide dismutase (SOD) is crucial antioxidant enzyme that plays a role in protecting cells against harmful reactive oxygen species (ROS) which are generated inside cells. Due to its functionality, SOD is used in many applications. In this study, Saccharomyces cerevisiae TBRC657 was selected as the SOD producer due to its high SOD production. After investigating an optimized medium, the major components were found to be molasses and yeast extract, which improved SOD production up to 3.97-fold compared to a synthetic medium. In addition, the optimized medium did not require any induction, which makes it suitable for applications in large-scale production. The SOD formulation was found to increase the stability of the conformational structure and prolong shelf-life. The results show that 1.0% (w/w) trehalose was the best additive, in giving the highest melting temperature by the DSF method and maintaining its activity at more than 80% after storage for 6 months. The obtained SOD was investigated for its cytotoxicity and ROS elimination against fibroblast cells. The results indicate that the SOD enhanced the proliferation and controlled ROS level inside the cells. Thus, the SOD obtained from S. cerevisiae TBRC657 cultured in the optimized medium could be a candidate for use as a ROS scavenger, which can be applied in many industries

Additional file 1: Table S1. of Biochemical characterization and synergism of cellulolytic enzyme system from Chaetomium globosum on rice straw saccharification

Comparison of cellulose production by C. globosum BCC5776 and other fungi in recent selected publications. (DOCX 16 kb

Overexpression of LAS21 in Cellulase-Displaying <i>Saccharomyces cerevisiae</i> for High-Yield Ethanol Production from Pretreated Sugarcane Bagasse

The valorization of lignocellulosic feedstocks into biofuels and biochemicals has received much attention due to its environmental friendliness and sustainability. However, engineering an ideal microorganism that can both produce sufficient cellulases and ferment ethanol is highly challenging. In this study, we have tested seven different genes that are involved in glycosylphosphatidylinositol (GPI) biosynthesis and remodeling for the improvement of cellulase activity tethered on the S. cerevisiae cell surface. It was found that the overexpression of LAS21 can improve β-glucosidase activity by 48.8% compared to the original strain. Then, the three cellulase genes (cellobiohydrolase, endoglucanase, and β-glucosidase) and the LAS21 gene were co-introduced into a diploid thermotolerant S. cerevisiae strain by a multiple-round transformation approach, resulting in the cellulolytic ECBLCCE5 strain. Further optimization of the bioprocess parameters was found to enhance the ethanol yield of the ECBLCCE5 strain. Scaling up the valorization of pretreated sugarcane bagasses in a 1 L bioreactor resulted in a maximum ethanol concentration of 28.0 g/L (86.5% of theoretical yield). Our study provides a promising way to improve the economic viability of second-generation ethanol production. Moreover, the engineering of genes involved in GPI biosynthesis and remodeling can be applied to other yeast cell surface display applications

Additional file 2: Table S2. of Biochemical characterization and synergism of cellulolytic enzyme system from Chaetomium globosum on rice straw saccharification

Sugar yields from hydrolysis of pretreated rice straw using various enzyme combinations and dosages. (DOCX 15 kb