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This study investigated the biosorption of lead, chromium and cadmium in tannery effluent using indigenous microorganisms. Bacteria isolated from the tannery effluent were Bacillus subtilis and B. megaterium while fungi isolated were Aspergillus niger and Penicillium sp. The microorganisms were tested for their ability to reduce the concentration of the heavy metals in the tannery effluent using conventional methods. B. megaterium recorded the highest lead reduction (2.13 to 0.03 mg/L), followed by B. subtilis (2.13-0.04 mg/L). A. niger recorded the highest ability to reduce the concentration of chromium (1.38-0.08 mg/L) followed by Penicillium sp. (1.38 0.13 mg/L) while B. subtilis exhibited the highest ability to reduce the concentration of cadmium (0.4-0.03 mg/L) followed by B. megaterium (0.04-0.06 mg/L) after 20 days. When these values were compared to standard limits of Federal Environmental Protection Agency (FEPA), World Health Organization (WHO), National Environmental Standard and Regulations Enforcement Agency (NESREA) and Central Pollution Control Board (CPCB), the isolates recorded an acceptable reduction in the concentration of lead, chromium and cadmium in sterile and unsterile tannery effluent. The results of this showed that the isolates reduced the concentration of lead, chromium and cadmium present in the sterile and raw tannery effluent and suggest that the organisms can be used as a possible treatment of tannery effluents.

Production of pectinase and cellulase by Aspergillus niger from corn cob was examined. The organism was screened for enzymatic activity using Carboxyl Methyl Cellulose (CMC) and Pectin as substrate. The result revealed a clear zone of inhibition in the agar plates. The organism was subjected to different optimum conditions which include pH, temperature, biomass yield and enzymatic activity. The highest cellulose activity was obtained on the 4 th day (1.9×10 -4 µg/ml/sec) while the highest pectinase activity (1.5×10 -4 µg/ml/sec) was obtained on the 4 th and 5 th day. The optimum pH for cellulase production was pH 4 with an activity of 2.70×10 -4 µg/ml/sec while the optimum pH for pectinase activity was pH 6 with an activity of 1.5×10 -4 µg/ml/sec. The optimum temperature was at 50 o C with an enzyme activity of 1.3x10 -4 µg/ml/sec for cellulase production while the optimum temperature of 60 0 C gave the highest pectinase activity of 1.6x10 -4 µg/ml/sec. This study revealed that Aspergillus niger from corn cob has the ability to produce cellulase and pectinase, hence it may be considered as a source for the production of industrial cellulase and pectinase.

Ten grams (10 g) of soil sample was obtained from a rice husk dumpsite in Sokoto metropolis and analyzed. The species isolated were Bacillus licheniformis, Bacillus lentus and Bacillus megaterium. The Bacillus species isolated were screened for amylolytic activities. The isolate with the widest zone of clearance (A 1 ) was selected for further analysis. The highest activity was observed in B. licheniformis (2.00±0.01 mm) followed by B. lentus (1.96±0.40 mm) and B. megaterium (1.70±0.18 mm) had the least activity. Amylase activity was determined using DNS method. The optimum temperature for the activity of the amylase produced was obtained at 90 °C with a concentration of 0.373 mg/ml. Optimum pH activity was obtained at 4.0 with a concentration of 0.376 mg/ml. Bacillus licheniformis has the greatest potential for producing amylase than the other isolates and rice husk can be exploited for amylase production. The B. licheniformis strain produced thermostable alpha-amylase with characteristics suitable for application in starch processing and other food industries.