Background: Owing to the importance of enzyme in fruit processing, demand in quality pectinase has increased. As a result, understanding the properties of locally produced pectinase is very important to encourage promotion in its application in the industry. In this study, Aspergillus niger was isolated, screened for its ability to secrete pectinase. The screened Aspergillus niger was used to produce pectinase using solid state fermentation of orange peels. Results: The effect of temperature and its stability, pH and its stability, substrate concentration, metal ions (Na+, Ca2+, Mg2+, K+, Mn2+, Zn2+, Co2+, and Fe2) were also investigated. The characterized pectinase was applied in the clarification of both orange and pineapple juices. The findings revealed that the enzyme was most effective at 50oC and relatively stable at 20oC activity of about 0.50 mg/ml for both. The optimal pH of 5 at about 0.50 mg/ml, and stabilized pH of 4 with approximately similar activity was also obtained. Of the metals ions investigated, Na+ gave the highest activity of about 0.61 mg/ml compared to ethylenediamine tetraacetic acid (EDTA) which displayed an inhibitory effect. On further optimizing for the concentration of Na+, low concentration of the ion (10 mM) had higher activity of about 0.61 mg/ml. The (Km) and Vmax was about 0.36 mg/ml and 4.39 U/ml. Conclusion: The characterized pectinase clarified both orange and pineapple juices, with enhanced clarification in orange juice compared to pineapple juice. Therefore, the characterized crude pectinase was suitable for application in the clarification of juices.

Background: Pectin enzymes are biocatalysts that degrade pectin into simpler forms. Fermentation is the commonly utilized method for pectinase production. Prior to optimization of pectinase activity, preliminary findings were undertaken to select the best screened microbe (Aspergillus niger), agrowastes and extraction solvents. Solid-state fermentation was employed in the study (optimization process), utilizing the Box-Behnken design in Design-Expert software package version 12.0.3. Results: The results showed 0.1 molar sodium chloride as the best extraction solvent, with the activity higher than the citrate buffer. However, pectinase activity obtained with distilled water was significantly (p<0.05) lower than 0.1 molar sodium chloride. For the substrates employed in the study, the citrus (orange) peel had the highest pectinase activity of ≈0.40 mg per ml. The activity of citrus peels was significantly higher than the activities from each of corn cob, banana peel, wheat bran, Thaumatococcus danielli fruit wastes and Thaumatococcus danielli leaves. A significant increase (p<0.05) in pectinase activity was also obtained with Thaumatococcus danielli fruit wastes relative to Thaumatococcus danielli leaves. Pichia kudriavzevii strain F2-T429-5 and Pichia kudriavzevii strain CY902 have been identified to complement for pectinase production. From the results obtained, the optimum conditions for pectinase production were approximately 5.87 days of fermentation; pH of 3.90; at 21.24 oC; particle size of 0.06-inch; inoculum volume of 1.00 ml, and agitation time (for pectinase extraction) at 11.43 minutes. Optimisation of the selected conditions using the Box-Behnken design and analysis as a statistical tool resulted in a higher activity. Conclusion: Local production of pectinase would help in reducing hunger through local job creation, thereby positively contributing to the Sustainable Development Goals (SDGs).

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Microbial alkaline protease is one of the dominant industrial enzymes which function in splitting polypeptides chain of protein into monomers of amino acids and peptides. This study aimed to identify alkaline protease produced by Bacillus sp. Soil samples were aseptically collected from dump sites in FIIRO, Lagos state, Nigeria. The samples were serially diluted, and bacteria were isolated using pour plate method. The resulting isolates were screened and morphologically characterized. The isolate with the highest protease production potential was subjected to biochemical characterization using Analytical Profile Index (API) identification kit system and 16S rRNA sequencing. The selected isolate was used to produce alkaline protease by solid state fermentation using rice bran as a substrate. Out of the 18 bacteria isolated, 11 isolates showed alkaline protease production potential. Isolate C3a-FIIRO was selected for its maximal alkaline protease produced as indicated by a 56 mm zone of clearance. Morphological and biochemical characterization revealed isolate C3a-FIIRO as a member of the genus Bacillus. The 16S rRNA gene sequencing confirmed the isolate as Bacillus subtilis C3a-FIIRO (MW577298) with closest homology to Bacillus subtilis Y17B. The enzyme activity of 6848.171 U/ml ± 0.11 and protein concentration of 152.13 mg/ml ± 0.003 showed that Bacillus subtilis C3a-FIIRO has potential for sustainable alkaline protease production.