Parallel evolution of the make–accumulate–consume strategy in Saccharomyces and Dekkera yeasts

Saccharomyces yeasts degrade sugars to two-carbon components, in particular ethanol, even in the presence of excess oxygen. This characteristic is called the Crabtree effect and is the background for the 'make–accumulate–consume' life strategy, which in natural habitats helps Saccharomyces yeasts to out-compete other microorganisms. A global promoter rewiring in the Saccharomyces cerevisiae lineage, which occurred around 100 mya, was one of the main molecular events providing the background for evolution of this strategy. Here we show that the Dekkera bruxellensis lineage, which separated from the Saccharomyces yeasts more than 200 mya, also efficiently makes, accumulates and consumes ethanol and acetic acid. Analysis of promoter sequences indicates that both lineages independently underwent a massive loss of a specific cis-regulatory element from dozens of genes associated with respiration, and we show that also in D. bruxellensis this promoter rewiring contributes to the observed Crabtree effect

Dietary supplementation with hydrolyzed yeast and its effect on the performance, intestinal microbiota, and immune response of weaned piglets.

The objective of this study was to evaluate the effects of autolyzed yeast on performance, cecal microbiota, and leukogram of weaned piglets. A total of 96 piglets of commercial line weaned at 21-day-old were used. The experimental design was a randomized block design with four treatments (diets containing 0.0%, 0.3%, 0.6%, and 0.9% autolyzed yeast), eight replicates, and three animals per pen in order to evaluate daily weight gain, daily feed intake, and feed conversion in periods of 0 to 15, 0 to 26, and 0 to 36 days. Quadratic effects of autolyzed yeast inclusion were observed on the feed conversion from 0 to 15 days, on daily weight gain from 0 to 15 days, 0 to 26 days and, 0 to 36 days, indicating an autolyzed yeast optimal inclusion level between 0.4% and 0.5%. No effect from autolyzed yeast addition was observed on piglet daily feed intake, cecal microbiota, and leukogram; however, i.m. application of E. coli lipopolysaccharide reduced the values of total leukocytes and their fractions (neutrophils, eosinophils, lymphocytes, monocytes, and rods). Therefore, autolyzed yeast when provided at levels between 0.4% and 0.5% improved weaned piglets’ performance.info:eu-repo/semantics/publishedVersio

In vivo and in vitro sensitization of leukemic cells to adriamycin-induced apoptosis by pentoxifylline: Involvement of caspase cascades and I?B? phosphorylation

An osmotolerant low pH resistant wild type Saccharomyces cerevisiae ITV-01 yeast was employed to obtain respiratory deficient (RD) strains in order to improve ethanol production. The respiratory deficient phenotype was induced by exposure to chemical agents such as ethidium bromide, rhodamine, and ethanol. Isolation with physical agents such as temperature and UV radiation (254 nm) exposures was evaluated. 104 strains were tested. Selection criterion was based on increasing ethanol yield. All RD strains had higher ethanol yields (from 0.41 to 0.50 gg-1, corresponding 82-98% theoretical yields) than the wild type yeast (0.40 gg-1). Temperature and ethanol mutant agents caused a reversible phenotype in every case. Screening showed that S. cerevisiae ITV-01 RD-B14 (lacking cytochrome c), obtained using bromide ethidium, had the highest alcoholic fermentation efficiency (95%) and 97% viability under the tested conditions (150 gL-1 glucose, pH 3.5). The respiratory deficient mutation is of interest as a tool for improving ethanol production. " 2011 Elsevier Ltd.",,,,,,"10.1016/j.renene.2011.06.019",,,"http://hdl.handle.net/20.500.12104/42115","http://www.scopus.com/inward/record.url?eid=2-s2.0-79961111322&partnerID=40&md5=1c66036daa8f9a8c9e830045dfe8e2ca",,,,,,"1",,"Renewable Energy",,"19

Improvement in ethanol production using respiratory deficient phenotype of a wild type yeast Saccharomyces cerevisiae ITV-01

An osmotolerant low pH resistant wild type Saccharomyces cerevisiae ITV-01 yeast was employed to obtain respiratory deficient (RD) strains in order to improve ethanol production. The respiratory deficient phenotype was induced by exposure to chemical agents such as ethidium bromide, rhodamine, and ethanol. Isolation with physical agents such as temperature and UV radiation (254 nm) exposures was evaluated. 104 strains were tested. Selection criterion was based on increasing ethanol yield. All RD strains had higher ethanol yields (from 0.41 to 0.50 gg-1, corresponding 82-98% theoretical yields) than the wild type yeast (0.40 gg-1). Temperature and ethanol mutant agents caused a reversible phenotype in every case. Screening showed that S. cerevisiae ITV-01 RD-B14 (lacking cytochrome c), obtained using bromide ethidium, had the highest alcoholic fermentation efficiency (95%) and 97% viability under the tested conditions (150 gL-1 glucose, pH 3.5). The respiratory deficient mutation is of interest as a tool for improving ethanol production. © 2011 Elsevier Ltd