BACKGROUND Bioethanol produced by the yeast Saccharomyces cerevisiae is currently one of the most promising alternatives to conventional transport fuels. Lignocellulosic hemicelluloses obtained after hydrothermal pretreatment are important feedstock for bioethanol production. However, hemicellulosic materials cannot be directly fermented by yeast: xylan backbone of hemicelluloses must first be ...

The influence of dilution rate on the production of biomass, ethanol, and invertase in an aerobic culture of Succharornyces carlsbergensis was studied in a glucoselimited chemostat culture. A kinetic model was developed to analyze the biphasic growth of yeast on both the glucose remaining and the ethanol produced in the culture. The model assumes a double effect where glucose regulates the flux...

Metabolic engineering is a powerful method to improve, redirect, or generate new metabolic reactions or whole pathways in microorganisms. Here we describe the engineering of a Saccharomyces cerevisiae strain able to utilize the pentose sugar L-arabinose for growth and to ferment it to ethanol. Expanding the substrate fermentation range of S. cerevisiae to include pentoses is important for the u...

Several yeast species, belonging to Saccharomyces and non-Saccharomyces genera, play fundamental roles during spontaneous must grape fermentation, and recent studies have shown that mixed fermentations, co-inoculated with S. cerevisiae and non-Saccharomyces strains, can improve wine organoleptic properties. During active dry yeast (ADY) production, antioxidant systems play an essential role in ...

Rhodotorula kratochvilovae (syn, Rhodosporidium kratochvilovae) SY89, an oleaginous yeast, isolated from Ethiopian soil, was grown under nitrogen-limited media. The capacity this with respect to biomass production, lipid yield and lipid content was evaluated. The influence of inoculum size, carbon sources, variations in glucose concentration, nitrogen sources, C/N ratio, pH, temperature, agitat...

In the present study Kluyveromyces marxianus isolated from paneer whey was employed for biomass production. Various parameters like pH, temperature and nitrogen source were optimized for maximum biomass yield. The biomass yield was studied to vary with different nitrogen sources, pH and temperature. Ammonium sulphate, ammonium nitrate, beef extract and yeast extract were used as nitrogen source...

Microalgae have a high growth rate, CO2 absorption capacity, and content of chlorophyll, proteins, vitamins, mineral salts, carbohydrates, antioxidant substances, fatty acids. In recent years, Chlorella vulgaris has been widely used as feedstock for producing third-generation biofuels, such bioethanol. Thus, this work aims to develop strategy increase the production scale microalgae grown in di...

BACKGROUND Baker's yeast, Saccharomyces cerevisiae, as one of the most often used workhorses in biotechnology has been developed into a huge family of application optimised strains in the last decades. Increasing numbers of strains render their characterisation highly challenging, even with the simple methods of growth-based analytics. Here we present a new sensor system for the automated, non-...

Fuel-ethanol fermentation process includes a reutilization of the yeast biomass, in which yeast cells are exposed to stress conditions as high temperature and increasing alcohol concentration. This environment may cause a significant delay in fermentation and drop in cell viability. The Bioen program (UNESP) conducted a study to select highly producing yeast strains in a Brazilian distillery. T...

This study investigated the effect of heat and ethanol on fermentable yeast cells. Fermentable yeast cells (Saccharomyces cerevisiae strains and non-saccharomyces species) were subjected to varying temperature (37, 40 and 44°C) and ethanol concentration (8, 10, 14 and 18%) respectively. In the research, 55.35% of the fermentable yeasts were highly thermotolerant, moderately thermotolerant (42.8...