REDUCTION OF RNA AND DNA IN METHYLOCOCCUS-CAPSULATUS BY ENDOGENOUS NUCLEASES

A method for reducing RNA and DNA in the bacterium Methylococcus capsu latus (Bath) has been developed. Endogenous RNase and DNase were activ ated by a 10 s heat shock at 90 degrees C. Cells were then incubated a t 60 degrees C for 20 min to allow degradation of the nucleic acids. T he optimum pH for the process was 7.0. The protein loss was less than 10% and occurred during the initial heat shock. No protein loss was fo und during incubation. The total dry-weight loss in connection with an 80% reduction of the nucleic acid content was 20%-25%, giving a final product with a raw protein content of approximately 75%. Reduction of both RNA and DNA was inhibited by CuSO4 and ZnSO4. DNA reduction was stimulated by minerals. Optimal stimulation was found at FeSO4. Reduct ion of RNA was not increased by any of the minerals tested.