가축축사와 양조장에서 야생효모의 분리와 추출조건

Abstract

Yeast extract is used as food and animal additives. The study was conducted the selection and isolation of wild type yeast with excellent autolysis to produce nutritious yeast extract and to use with prebiotics. A number of wild yeasts were isolated from Korean domestic stable, brewery, and food. Isolated yeasts were identified by comparison of nucleotide sequences for polymerase chain reaction-amplified ITS1/4 region of 18S rRNA using BLAST. In order to investigate the optimal autolysis conditions, the selected strains were autolysed by several methods (e.g. ethanol, autoclaving, homogenizing, deep freezing, NaCl, NaOH, nitrogen, protease, ultrasonicating, and pH). The efficiency of yeast cell autolysis was evaluated with contents of β-glucan and mannan in autolysates. Sixty-four yeast strains were isolated from 148 samples from yeast selection medium, yeast-mold agar (YMA) supplemented with 10% ethanol, and thirteen yeast species were identified by BLAST. Most stain of thirteen yeast were autolyzed about 65% by autoclave condition (121℃). S. cerevisiae strain P1 showed 31% of autolysis at pH 4.4 condition for 72 hrs. The results suggest that the newly isolated wild-type yeast and the newly developed hydrolysis conditions can be used in the development of animal feed additives.