Solid state fermentation of soybean waste and an up-flow column bioreactor for continuous production of camptothecine by an endophytic fungus Fusarium oxysporum

Abstract

The potential of an endophytic fungus Fusarium oxysporum (NCIM 1383) to produce the anti-cancer pro-drug ‘camptothecine (CPT)’ by solid state fermentation (SSF) of agro-industrial by-products was investigated. Amongst the various substrates used under optimized SSF conditions, soybean meal was found to be the most efficient medium for optimum production of CPT by the fungus. The effect of the addition of different complex protein sources to the soybean meal substrate on productivity by the fungus was also studied. The CPT production was found to be increased by 46.87% after supplementation of “whey concentrate powder” as a complex protein source to the soybean meal. The optimized SSF conditions were used to develop a bench-scale, up flow bioreactor to check its applicability for continuous CPT production which could yield up to 128 mg l⁻¹ CPT after 48 h of incubation. Whey, when used as a source of moisture in SSF, also was found to play a vital role in enhancing the CPT yield. Environmental parameters such as chemical oxygen demand (COD), biological oxygen demand (BOD), total dissolved solids (TDS), total soluble solids (TSS) and total protein content of whey effluent after fermentation were found to be reduced significantly highlighting the environmental applications of the process developed. The SSF methodology applied in the present study allows bioutilization of cheaper substrates; soybean meal and whey, by the endophytic fungus for production of valuable anti-cancer pro drug CPT.