Tannic acid resistance in ruminal streptococcal isolates.

Tannin degrading isolates of Streptococcus spp. from rumen of non-adaptive cattle, when grown in BHI broth, were able to tolerate tannic acid upto a level of 50 g/l. An increase in lag period from 1.5 to 6 h was observed for the isolates in presence of increased concentration of tannic acid. In addition, the morphology of gram positive diplococci converted to an elongated chain of 40-50 cells with increasing tannic acid from 1 to 4%. Qualitatively, the tannase activity was found to be present in the isolates tested, indicating their potential of being a tannin degrader. Copyright 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.