Intra and extracellular nuclease production by Aspergillus niger and Aspergillus nidulans

Intra and extracellular nuclease production by strains of "Aspergillus niger"and "Aspergillus nidulans" was estimated using a modified DNAse test agar and cell-0free extract assays. Differences in the production of nucleases by A. niger and A. nidulans were observed. These observations suggest that the DNAse test agar can be helpful for a quick screening for some types of nucleases in filamentous fungi. The assays using cell-free extracts can also be useful for initial characterization of other types of nucleases.

Enzymatic activity of a group C Streptococcus in a penicillin-medium

Dye-binding assays were employed to study the effects of penicillin on the production of hyaluronidase and deoxyribonuclease by a group C streptococcal strain. Enzymatic activities were measured in supernates of bacterial cultures that had been exposed to low concentrations of the drug during growth. The addition of antibiotic resulted in an increase in the production of hyaluronidase and in a decrease in that of deoxyribonuclease. These alterations in the elaboration of extracellular substances and their release into the frowth environment could be of importance as the Streptococcus is affected in vivo during treatment with penicillin.