Precise utilization of fruit and vegetable waste as a substrate for the multienzyme production by Bacillus subtilis NG105 and Trichoderma asperelllum NG125

Abstract

We earlier identified Bacillus subtilis NG105 and Trichoderma asperelllum NG125 isolated from fruit and vegetable wastes (FVWs) and established that multienzyme activity viz pectinase, cellulase and amylase (PC&A) activity was localized exclusively in cell exudates (CEs). In this study, we evaluated the best rotten or leftover FVWs of Bael, Guava, Mosambi, Beetroot, Banana, Aonla, Mango and Cabbage as potential substrates under solid-state fermentation (SSF) for isolated microbial strains to multi-enzyme production. The results showed that after SSF, the multienzyme activity of microbial CEs of both NG105 (394.6, 296.1, 341.4 μmol ml−1min−1 of PC&A respectively) and NG125 (420.5, 347.3, 330.7 μmol ml−1min−1 of PC&A respectively) extracted from mosambi peel performed best. The multienzyme present in CEs was further partially purified using five different chemical solvents; acetone, trichloroacetic acid, ammonium sulphate (70%), ethanol, and n-propanol. Results revealed that partially purified multienzyme (PPM) of both NG105 (415.2, 425.4, 414.3 μmol ml−1min−1 of PCA respectively) and NG125 strain (528.5, 509.2, 467.6 μmol ml−1min−1 of PC&A respectively) found to be highest in PPM extracted with acetone. The result indicates that mosambi peel may be used as the best FVWs as the substrate for our isolated strains for multienzyme production and the acetone purification method was well suited for the enhancement of the enzymatic activity. Moreover, the produced multienzyme (in CEs form) either in the system in which they are produced (eg. juice clarification) or extracted and partially purified form may be further utilized for other purposes (eg. food, animal feed, bio-fuel, detergent, industries etc).