Effect of UV-irradiation on some aspects of metabolic activities in Aspergillus flavus and Penicillium notatum.

Near-UV (NUV) irradiation was found to stimulate protein synthesis in Penicillium notatum and Aspergillus flavus. DNA was also induced by short periods of NUV (10 and 20 min) in P. notatum. Synthesis of DNA in A. flavus decreased under the same treatment and then increased when irradiation was for long periods. The reverse of this observation was seen in the case of RNA synthesis, while RNA synthesis was significantly inhibited by NUV in P. notatum. Induction of RNA synthesis was observed in A. flavus. Far-UV (FUV) irradiation induced protein synthesis in P. notatum and A. flavus; the increase was more pronounced in A. flavus. FUV slightly inhibited DNA synthesis in P. notatum, but the synthesis in A. flavus was fairly constant. RNA synthesis was reversed to a certain extent by FUV in both fungi. UV irradiation produced no effect on the process of lipid synthesis. Total soluble carbohydrates were decreased by NUV in P. notatum and increased markedly in A. flavus (240 min NUV). FUV irradiation resulted in an increase in total soluble carbohydrates in both fungi.