Effect of plant extracts on microbial profile changes in vitro ruminal cultures

Abstract

Indiscriminate use of antibiotics will lead to antibiotic resistance among the zoonotic animals, thus plant compounds seems to be better alternative strategy to use in animal feed for methane mitigation. In our previous work, plant extracts such as Tribuli terrestris (TS), Alnus japonica (AJ), Carpinus tschonoskii (CJ), Semen pharbitidis (PS), Acer truncatum (AT), Vitex negundo (VN), Amelanchier asiatica (AA) and Reynoutria sacha (RS) decreases ruminal methane emissions in vitro. In continuation, the aim of the present study was to quantify the relative abundance of Ruminococcus flavefaciens, R. albus, fibrobacter succinogenes, protozoa and total methanogenic archaea by real-time PCR analysis. DNA was isolated from the extract treated rumen samples followed by RT-PCR. We used 16s rRNA specific primer for quantification of cellulolytic bacteria, methanogens and 18S rRNA for protozoan populations. The plant extracts VN, AA, RS, AJ and AT decreased the abundance of protozoa and methanogen population as compared to control. The extracts TS, CT, VN, AA and RS increased all cellulolytic bacteria. Whereas, AJ and AT increased F. succinogenes and R. albus species. In conclusion, the plant extracts appear to have anti-methanogenic properties by inhibiting protozoa and methanogen population.