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Selection and identification of oleaginous yeast isolated from soil, animal feed and ruminal fluid for use as feed supplement in dairy cattle
Author(s) -
Paserakung A.,
Pattarajinda V.,
Vichitphan K.,
Froetschel M.A.
Publication year - 2015
Publication title -
letters in applied microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.698
H-Index - 110
eISSN - 1472-765X
pISSN - 0266-8254
DOI - 10.1111/lam.12475
Subject(s) - yeast , oleic acid , food science , yeast extract , biology , urea , biomass (ecology) , agar , fermentation , botany , biochemistry , bacteria , agronomy , genetics
The purpose of this study was to select oleaginous yeast for microbial lipid production. Sixty‐four yeast isolates were obtained from soil (GSY1–12), animal feeds (FDY1–21), and ruminal fluid (RMY1–31) using yeast extract peptone dextrose (YPD) agar. The cultivation of these isolates on nitrogen limited‐medium revealed that GSY2 to GSY6, GSY10, FDY2, FDY12 and FDY14 accumulated lipid over 20% of dry biomass. Therefore, they were preliminarily classified as oleaginous yeast. In subsequent experiment, an 8 × 3 factorial in completely randomized design was conducted to examine the effect of eight oleaginous yeast strains and three nitrogen sources (peptone, (NH 4 ) 2 SO 4 , urea) on lipid accumulation when using molasses as substrate. The result illustrated that only GSY3 and GSY10 accumulated lipid over 20% of biomass when using peptone or (NH 4 ) 2 SO 4 but urea did not. However, GSY10 gave higher biomass and lipid yield than GSY3 ( P < 0·05). Identification of GSY10 using 26S rDNA illustrated that GSY10 belongs to Trichosporon asahii . Fatty acid profiles of this strain contained unsaturated fats up to 62·5% of which oleic acid (C 18:1 ) was predominant. In conclusion, T. asahii GSY10 was the most promising oleaginous yeast for microbial lipid production from molasses. Significance and Impact of the Study This study illustrated the ability of T. asahii GSY10 to utilize molasses and (NH 4 ) 2 SO 4 for synthesizing and accumulating cellular lipid of which oleic acid (C 18:1 ) was predominant. This yeast would be used for microbial lipid production used as feed supplement in dairy cattle.