Cassava peels are generated as waste on soils during cassava processing in many tropical countries. This work set out to isolate some microorganisms associated with cassava peel degradation and characterize amylase enzymes responsible for the degradation under some physiological conditions. A total of 30 bacteria was isolated from the peels with Bacillus species occurring the most (46.5%) and Enterobacter species (13.3%) being the next. Frequencies of fungal isolations was Rhizopus sp. (35%); Aspergillus niger (25%); Aspegillus flavus (20%) and Penicillium species (20%). Bacillus cereus, Bacillus substilis Bacillus pumillus, Aspergillus niger and Apergillus flavus were selected and screened for their abilities to produce amylase. Amylase activity was highest at day 4 for B. substilis (39.4 units/ml) and A. flavus (66.1 units/ml); at day 3 for B. cereus (55.6 units/ml) and A. niger (44.6 units/ ml). While maximum amylase activity was obtained at day 6 for B. pumilus (80.2 units/ml). Optimum pH for amylases from the two fungal isolate was 6.0 (A. niger = 53.5 units/ml and A. flavus = 65.4 units/ml). While optimum pH for B.cereus (51.7 units/ ml) and B. pumilus (44.6 units/ml) was 6.5 and for B. substilis (56.1 units/ml) at pH 7.0. Amylase activities increased from 20˚C to 40˚C for amylase from Bacillus sp. and 20˚C to 50˚C for amylase from the Aspergillus sp. after which there was a decline in activities as temperature increased to 80˚C. Effect of heating duration (at 70˚C for 5 minutes) on the amylase showed that A. niger has the highest activity of 127 units/ml. Effect of substrate concentration on amylase activity showed that amylase form A. flavus had the highest activity of 72.2 units/ml at 0.4% substrate concentration. The implications of the findings were discussed.

Samples of peels and soils from cassava waste sites were collected from cassava processing factory in Oyo town, Oyo State and also a dumpsite in Alaya village, Aiyedire local government, Osun State, Nigeria. Bacterial isolation was carried out using the pour plate method to obtain amylolytic bacterial species capable of hydrolyzing starch. Fourteen bacterial isolates that were most responsive to starch hydrolysis were selected from both sampling sites for molecular investigations. DNA of the isolates was extracted and subjected to a cocktail mix and condition for PCR which was purified using two universal primers and afterwards the PCR product was used for the polymorphism through electrophoresis. Bacterial isolates were identified based on their genetic sequences and results showed Bacillus subtilis (21.44%) to be the most frequently occurring specie. There was the prevalence of two similar strains Bacillus subtilis MML2483 and B. subtilis MML2411 which was isolated from the different sampling sites. Some other bacterial strains included Bacillus olivae BRB18, B. licheniformis HT-26-B1, B. cereus H17, B. safensis MS40, B. pumilus 07.