Omega-3 Fatty Acids Production and Ruminal Degradability of Recombinant <I>Saccharomyces cerevisiae </I> Harboring Fatty Acid Desaturase 2 Gene (<I>FAD2</I>)

Abstract

The objective of this study were produce recombinant Saccharomyce cerevisiae harboring fatty acid desaturase 2 gene (FAD2) isolated from Saccharomyce kluyveri, then evaluated omega-3 of recombinant S. cerevisiae and ruminal degradability of roughage supplemented with recombinant S. cerevisiae. Total DNA extracted from S. kluyveri was used for PCR amplification using FAD2 gene primer. PCR products was cloned using plasmid vector pTA2 and transformed with S. cerevisiae. The fatty acids were analyses by gas chromatography. The ruminal degradability by in vitro gas production technique was designed as 3x3 factorial in completely randomized design (CRD) arrangement of 9 treatments. The factors were type of roughage (guinea grass silage: GN), rice straw: RS and napier grass silage: NP), and yeast supplementation (control: C, S. cerevisiae :SC and recombinant S. cerevisiae harboring FAD2 gene from S. kluyveri: SCSK). The rumen fluid was collected from four fistulated Thai native cattles. Gas production were determined at 2, 4, 6, 8, 10, 12, 24, 48, 72 and 96 h of incubation while the microbial biomass yield (MBY) were determined at 24 h of incubation. The results found that the Linoleic acid (C18:2, LA), Alpha-linolenic acid (C18:3, ALA) and Eicosapentaenoic acid (C20:5, EPA) content of recombinant S. cerevisiae higher than S. cerevisiae (P<0.05). Gas production at 2-12 hours of napier grass silage was significantly highest.  Gas production at 24 and 48 hours of roughage supplemented with SCSK was significantly highest. It can be concluded that recombinant S. cerevisiae produced LA, ALA and EPA higher than S. cerevisiae. The roughage supplemented with recombinant S. cerevisiae have highest OMD and SCFA.