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1.
Appl Environ Microbiol ; 90(1): e0175923, 2024 01 24.
Artigo em Inglês | MEDLINE | ID: mdl-38112453

RESUMO

The isolation and selection of yeast strains to improve the quality of the cachaça-Brazilian Spirit-have been studied in our research group. Our strategy considers Saccharomyces cerevisiae as the predominant species involved in sugarcane juice fermentation and the presence of different stressors (osmolarity, temperature, ethanol content, and competition with other microorganisms). It also considers producing balanced concentrations of volatile compounds (higher alcohols and acetate and/or ethyl esters), flocculation capacity, and ethanol production. Since the genetic bases behind these traits of interest are not fully established, the whole genome sequencing of 11 different Saccharomyces cerevisiae strains isolated and selected from different places was analyzed to identify the presence of a specific genetic variation common to cachaça yeast strains. We have identified 20,128 single-nucleotide variants shared by all genomes. Of these shared variants, 37 were new variants (being six missenses), and 4,451 were identified as missenses. We performed a detailed functional annotation (using enrichment analysis, protein-protein interaction network analysis, and database and in-depth literature searches) of these new and missense variants. Many genes carrying these variations were involved in the phenotypes of flocculation, tolerance to fermentative stresses, and production of volatile compounds and ethanol. These results demonstrate the existence of a genetic profile shared by the 11 strains under study that could be associated with the applied selective strategy. Thus, this study points out genes and variants that may be used as molecular markers for selecting strains well suited to the fermentation process, including genetic improvement by genome editing, ultimately producing high-quality beverages and adding value.IMPORTANCEThis work demonstrates the existence of new genetic markers related to different phenotypes used to select yeast strains and mutations in genes directly involved in producing flavoring compounds and ethanol, and others related to flocculation and stress resistance.


Assuntos
Perfil Genético , Saccharomyces cerevisiae , Saccharomyces cerevisiae/genética , Fermentação , Etanol , Fenótipo , Genômica
2.
J Ind Microbiol Biotechnol ; 46(5): 709-723, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30680472

RESUMO

Wickerhamomyces anomalus strain LBCM1105 was originally isolated from the wort of cachaça (the Brazilian fermented sugarcane juice-derived Brazilian spirit) and has been shown to grow exceptionally well at high amounts of glycerol. This paramount residue from the biodiesel industry is a promising cheap carbon source for yeast biotechnology. The assessment of the physiological traits underlying the W. anomalus glycerol consumption ability in opposition to Saccharomyces cerevisiae is presented. A new WaStl1 concentrative glycerol-H+ symporter with twice the affinity of S. cerevisiae was identified. As in this yeast, WaSTL1 is repressed by glucose and derepressed/induced by glycerol but much more highly expressed. Moreover, LBCM1105 aerobically growing on glycerol was found to produce ethanol, providing a redox escape to compensate the redox imbalance at the level of cyanide-resistant respiration (CRR) and glycerol 3P shuttle. This work is critical for understanding the utilization of glycerol by non-Saccharomyces yeasts being indispensable to consider their industrial application feeding on biodiesel residue.


Assuntos
Cianetos/química , Etanol/química , Glicerol/química , Saccharomyces cerevisiae/metabolismo , Saccharomycetales/metabolismo , Aerobiose , Bebidas Alcoólicas , Biocombustíveis , Biomassa , Reatores Biológicos , Brasil , Candida , Cromatografia Líquida de Alta Pressão , Fermentação , Tecnologia de Alimentos , Glucose , Concentração de Íons de Hidrogênio , Microbiologia Industrial , Cinética , Prótons
3.
Appl Environ Microbiol ; 83(20)2017 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-28778887

RESUMO

The development of hybrids has been an effective approach to generate novel yeast strains with optimal technological profile for use in beer production. This study describes the generation of a new yeast strain for lager beer production by direct mating between two Saccharomyces cerevisiae strains isolated from cachaça distilleries: one that was strongly flocculent, and the other with higher production of acetate esters. The first step in this procedure was to analyze the sporulation ability and reproductive cycle of strains belonging to a specific collection of yeasts isolated from cachaça fermentation vats. Most strains showed high rates of sporulation, spore viability, and homothallic behavior. In order to obtain new yeast strains with desirable properties useful for lager beer production, we compare haploid-to-haploid and diploid-to-diploid mating procedures. Moreover, an assessment of parental phenotype traits showed that the segregant diploid C2-1d generated from a diploid-to-diploid mating experiment showed good fermentation performance at low temperature, high flocculation capacity, and desirable production of acetate esters that was significantly better than that of one type lager strain. Therefore, strain C2-1d might be an important candidate for the production of lager beer, with distinct fruit traces and originating using a non-genetically modified organism (GMO) approach.IMPORTANCE Recent work has suggested the utilization of hybridization techniques for the generation of novel non-genetically modified brewing yeast strains with combined properties not commonly found in a unique yeast strain. We have observed remarkable traits, especially low temperature tolerance, maltotriose utilization, flocculation ability, and production of volatile aroma compounds, among a collection of Saccharomyces cerevisiae strains isolated from cachaça distilleries, which allow their utilization in the production of beer. The significance of our research is in the use of breeding/hybridization techniques to generate yeast strains that would be appropriate for producing new lager beers by exploring the capacity of cachaça yeast strains to flocculate and to ferment maltose at low temperature, with the concomitant production of flavoring compounds.

4.
Cien Saude Colet ; 17(2): 445-52, 2012 Feb.
Artigo em Português | MEDLINE | ID: mdl-22267038

RESUMO

Infant Diarrhea is a major cause of morbidity and mortality in children and oral rehydration therapy (ORT) is required. This study evaluates the composition of ORT prepared by Community Health Agents (CHAs) working in Basic Health Units, assessing their profile and knowledge about ORT. After the CHAs answer specific questions, they are invited to prepare ORT using three methods. Glucose and sodium levels were then quantified and compared with WHO recommendations. ANOVA, Tukey and odds ratio were used for statistical analysis. 52 CHAs participated, mainly females, and 90.4% with full high school education. The adequacy of the ORT was 3.9; 9.8 and 28.9% for table spoon, measuring spoon and pinch and scoop, respectively. The ORT preparation by table spoon resulted in 88% of samples with dangerous levels of sodium (≥101 mmol/L). 38.5% of the CHAs had less than 2 years experience, leading to a 4.8 times greater risk of preparing ORT with high sodium. The CHAs indicated ORT as a treatment for diarrhea, though they were unaware of the side effects of inadequate preparation. The composition of the ORT produced by the CHAs was inadequate in all methods tested. The CHAs revealed a lack of knowledge of the side effects iof ORT with inadequate salt levels. The recommendation is to train the CHAs in ORT preparation.


Assuntos
Agentes Comunitários de Saúde/educação , Hidratação/normas , Glucose/análise , Soluções para Reidratação/química , Sódio/análise , Estudos Transversais , Diarreia Infantil/terapia , Humanos , Lactente , Recém-Nascido , Competência Profissional
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