Ionic valency of vanadium or chromium and the enzymatic activity in Streptomyces caeruleus

ABSTRACT

The results of this investigation establish the fact that addition of 10-6 - 10-4 M chromium to the culture media, mostly stimulated the test intra-and extra-cellular enzymes of Streptomyces caeruleus. In most cases the hexavalent ion was more effective than the trivalent. Furthermore, Cr6+, was more inhibitory to dry weight gain than Cr3+. In the meantime, V2+ was mostly suppressive [except on Ac-P and GPT], whereas, V5+ was mostly stimulatory [endopeptidase being the exception]. The dry weight gain was slightly reduced by the former vanadium form and severely suppressed by the latter form. Accordingly, it seemed that the toxicity of these transitional elements was more apparent when supplemented in their high valency state accompanied by increased enzyme activity. The latter could be attenuated by lowering the valency of the cationic form of the ions