Comparação entre os teores de carboidratos totais solúveis presentes em distintas frações da levedura Saccharomyces cerevisiae Meyen

Abstract

Comparison between the content of all soluble carbohydrates present in distinct fractions of the yeast Saccharomyces cerevisiaeStrains of Saccharomyces cerevisiae were quantitatively compared to the content of all soluble carbohydrates present in two kinds of fraction: the "washed" and the lysate fraction with the purpose of identifying the richest fraction to be used in programs of induction of disease protection in plants.The sugar contents in the "washed" fraction were related to residues from the culture medium and not to extracellular components. Preliminary assays determined criotrituration as an adequate method of cellular lysis. Relevant observation has been made regarding to the variability of all sorts of carbohydrate content present in the lysate fraction of different strains.Key words: carbohydrates, cell wall, elicitors, phytoalexin. RESUMOLinhagens de Saccharomyces cerevisiae foram quantitativamente comparadas quanto ao teor de carboidratos totais solúveis presentes em dois tipos de fração: o "lavado" e o "lisado", com o objetivo de identificar a fração mais rica para ser utilizada em programas de indução de proteção em plantas. Os teores de açúcares encontrados na fração "lavado" foram relacionados com os resíduos do meio de cultura e não com os componentes extracelulares. Testes preliminares determinaram a criotrituração como método adequado de lise celular. Observação relevante foi a grande variabilidade do teor de carboidratos presente no lisado de diferentes linhagens.Palavras-chave: carboidratos, parede celular, elicitores, fitoalexina.

Spent Brewer’s Yeast as a Source of Insoluble β-Glucans

“…Saccharomyces cerevisiae cells are very resistant, and due to the thickness and rigidity of the cell wall some simple methods such as ultrasound are not enough for cell death [ 134 ]. Each method has its advantages, so we must consider whether to obtain fragments or whole-spherical particles of β-glucans because cell lysis with glass beads or a strong chemical treatment will cause cell rupture at the beginning.…”