Azo reductase activity of microbial population from gastrointestinal tract segments of various animals species.

Azo reductase activity of microbial population of stomach, small intestine, caecum and large intestine of different animals was investigated. There was low activity in stomach flora of wistar rat and 3 strains of mice. Flora of proximal portion of small intestine in different species revealed that carnivorous animals exhibited maximum activity followed by grazing animals. Maximum activity in middle portion of small intestine was noted in dog (98.2%), while minimum was observed in guinea pig (23.3%). Majority of test animals revealed maximum floral azo reductase activity (58-98%) in caecum. Activity in proximal portion of large intestine was highest in dog while pigeon and guinea pig had least activity (23.3-27.1%). Appreciable microbial activity in distal end of large intestine was noted in sheep and goat. In all the 15 animal species investigated caecum showed maximum activity followed by pre and post caecal segments while stomach possessed the least. The results suggest that inter-species differences exist in microbial reductive activity which may be due to variation in composition and distribution of GI tract microflora and thus can influence toxicological implication of various dyes.