Screening and identification of a high-producing soluble protein yeast strain from rumen and optimization of fermentation conditions
XU Kai
CHI Zhi-li
CHAI Ying-nan
QUAN Hong-dong
LI Hong-yan
YE Lu-qian
LIU Zhan-ying
Abstract：The experiment aimed to isolate and screen yeast strains that are high in microbial protein production and tolerant to ammonium salts from the rumen of cattle.A total of five yeast strains were screened,named CZL-1,CZL-2,CZL-3,CZL-4,and CZL-5.The optimal temperature,pH value,microbial protein content,and ammonium salt tolerance of the five yeast strains were determined.The results showed that the optimal temperature of single factor test was 37 ℃,pH value was 5.0,and the fermentation period was 48 h.The biomass of CZL-3 reached the optimal level,and the protein content of yeast was increased by 42.50％from the initial 47.79％to 68.10％(P＜0.05).Through morphological observation,physiological and biochemical identification,and 18S rDNA sequence analysis,strain CZL-3 was identified as Candida tropicalis.When the NH4+concentration exceeded 0.6 mol/L,the microbial protein content of the five yeast strains significantly decreased(P＜0.05).The study indicates that the isolates have high yield of bacterial protein and resistance to ammonium salt,and are expected to be used as high quality strains in the fermentation production of bacterial protein feed.
Keywords：rumenyeast straincellular proteinfermentation condition optimization
Publication Date：2024-12-31
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：6( 101-106 )