Enzyme Activity of Microorganisms Associated with Fermented Husk and Testa of Cola acuminata

Abstract

The availability of microbial enzymes in addition to its low cost, large production, environmental protection, plasticity and chemical stability, makes them widely used for industrial processes. Agricultural and forestry waste which can serve as substrate in producing biologically important secondary metabolites such as cellular proteins, organic acids, prebiotic, enzymes are economically advantageous due to its low cost and availability. The study investigated and compared the potential of same micorganisms isolated from Cola acuminata husk and testa waste to produce hydrolytic, proteolytic and lipolytic enzymes. The screened enzymes included α-amylase, β-amylase, cellulase, protease and lipases using appropriate procedures, with their activity measured in μmol minG mLG. Microorganisms were isolated using standard microbiological techniques from Cola acuminata husk and testa subjected to liquid state fermentation for 10 days. Thirteen microorgainsms were isolated in all and examined for potentials to produce the named enzymes. The bacterial isolates included; Bacillus subtilis, Bacillus sphaericus, Bacillus cereus, Bacillus laterosporus, Bacillus licheniformis, Bacillus firmus, Micrococcus luteus and Lactobacillus fermentum. Trichoderma viridiae, Articulospora inflata, Aspergillus fumigatus, Aspergillus flavus and Aspergillus niger were the fungal species isolated. The α-amylase, β-amylase and cellulase activity of the bacterial isolates ranged from 0.093±0.006-0.383±0.015 μmol minG mLG. Protease activity ranged from 1.723±0.147-3.300±0.170 μmol minG mLG while the lipase from 1.000±0.160-1.500±0.200 μmol minG mLG. The activity of the fungal isolates on the other hand ranged from 0.013±0.005-0.430±0.001, 2.416±0.313-10.137±0.083 and 1.000±0.0502.267±0.289 μmol minG mLG for the hydrolytic, proteolytic and lipolytic enzymes respectively. Protease and lipase had highest activity. Bacterial and fungal isolates from the testa showed higher enzymatic activity as compared to same isolates from the husk. Kolanut husk and testa can thus serve as an alternative substrate for microorganisms for the production of the screened enzymes.