Identification of potential docosahexaenoic acid (22:6-3) biohydrogenating rumen bacteria by inoculum dilution-to-enrichment technique

摘要

Rumen bacteria are mainly responsible for the biohydrogenation of polyunsaturated fatty acids in the rumen. However, knowledge on biohydrogenation of docosahexaenoic acid (22:6n-3) is limited in the rumen. Butyrivibrio proteoclasticus is the only rumen bacteria known to date to be involved in 22:6n-3 hydrogenation. Studies showed that 22:6n-3 is extensively hydrogenated in the rumen. As such, there can be more than one bacterial species involved in 22:6n-3 hydrogenation. Identifying these bacterial species will help to understand the 22:6n-3 metabolism and more importantly the intermediate products formed in the rumen. In this study, we attempted to identify potential bacterial species involved in biohydrogenation of 22:6n-3 in the rumen by an inoculum dilution-to-enrichment technique in combination with bacterial 16S rRNA gene amplicon sequencing.