Sharpea azabuensis: a ruminal bacterium that produces trans-11 intermediates from linoleic and linolenic acid.

ABSTRACT

To investigate the metabolism of 182n-6 and 183n-3 by pure cultures of Sharpea azabuensis, two different strains (RL 1 and ST18) were each incubated in the presence of 40 µg ml-1 182n-6 or 183n-3. Pure cultures of Butyrivibriofibrisolvens D1 and Butyrivibrio proteoclasticus P18 were included as control treatments. Similar to the metabolism of B. fibrisolvens, both S. azabuensis strains converted 182n-6 or 183n-3 to cis-9, trans-11 CLA or cis-9, trans-11, cis-15 CLnA, after which it was further reduced to trans-11 181 or trans-11, cis-15 182, respectively. B. proteoclasticus additionally reduced trans-11 181 to 180. Trans-11, cis-15 182 was also further metabolized by B. proteoclasticus, although trans-11 181 did not accumulate, and only minor amounts of 180 were formed. The time frame of 182n-6 and 183n-3 biohydrogenation by S. azabuensis was comparable with B. fibrisolvens, indicating that S. azabuensis and B. fibrisolvens might be alternative biohydrogenators of 182n-6 and 183n-3 in the rumen.