UTILIZATION OF RAM HORN PEPTONE IN THE PRODUCTION OF GLUCOSE OXIDASE BY A LOCAL ISOLATE Aspergillus niger OC-3

Glucose oxidase (GO) is an enzyme that is used in many fields. In this study, ram horn peptone (RHP) was utilized as the nitrogen source and compared with other nitrogen sources in the production of GO by Aspergillus niger. To obtain higher GO activity, 14 A. niger strains were isolated from soil samples around Erzurum, Turkey. Among these strains, the isolate that was named A. niger OC-3 achieved the highest GO production. The production of GO was carried out in 100 mL scaled batch culture. The fermentation conditions such as initial pH, temperature, agitation speed, and time were investigated in order to improve GO production. The results showed that the cultivation conditions would significantly affect the formation of GO, and the utilization of the RHP achieved the highest enzyme production (48.6 U/ mL) if compared to other nitrogen sources. On the other hand, the maximum biomass was obtained by using the fish peptone (7.2g/L), while RHP yielded 6.4 g/ L. These results suggest that RHP from waste ram horns could effectively be used in the production of GO by A. niger OC-3.