Production of bacterial amylases and cellulases using sweet potato (Ipomoea batatas. (L.) Lam.) peels

Abstract

Peels of sweet potato (Ipomoea batatas) were buried in the soil for 14 days and the isolates associated with the degradation of the peels were obtained using standard microbiological procedures. The bacterial isolates obtained were screened for amylolytic and cellulolytic activities under different pH and temperatures as parameters and optimized for enzyme production. Sixteen (16) bacterial isolates were obtained and characterized and screened for amylase and cellulase production. Bacillus pumilus has the highest frequency of occurrence (18.75%) followed by B. subtilis (12.50%). After 24 to 48 h of incubation, B. pumilus produced highest concentration of amylase at 55°C, pH 6 (5.4 U/mL) while B. subtilis had the best cellulase production of 0.75 U/mL at 55°C, pH 7. B. pumilus and Bacillus subtilis produced the highest amylase and cellulase concentrations and seem to be the potential sources of these enzymes for industrial application.

Isolation of Bacteria with Potential of Producing Extracellular Enzymes (Amylase, Cellulase and Protease) from Soil Samples

“…The most frequent of all the bacteria isolated from soil samples in this study was Bacillus species which is in line with the work of Wang et al [2] [2,14,15]. Ability of Amylase-producing bacteria were observed with their ability to hydrolyse starch agar which is in line the work of Olanbiwoninu and Fasiku [5]. Bacteria with cellulolytic properties degraded carboxymethylcellulose in carboxymethylcellulose agar which corroborates with the findings of Olanbiwoninu and Fasiku [5].…”

“…Amylolytic property of the isolated bacteria was screened using Nutrient agar supplemented with 1% starch. Clear zone around the organism after flooding with Gram's iodine indicates the ability of the bacterium to produce amylase [5].…”

“…Nutrient agar supplemented with 1% carboxy methyl cellulose (CMC) was used to screen ability of the isolated bacteria for cellulase production. Appearance of a clear zone against red colour of Congo red shows that the organism has ability to produce cellulase [5].…”

“…Among bacteria often isolated from soil are Bacillus species, Pseudomonas species, Enterobacter species, Staphylococcus species, Klebsiella species and others [2][3][4]. Amylase breaks down starch to simple sugar while cellulose is hydrolysed by cellulase and protease degrades protein [5]. Amylases are used in biofuel industries to break starch to fermentable sugar [5,6].…”

“…Amylase breaks down starch to simple sugar while cellulose is hydrolysed by cellulase and protease degrades protein [5]. Amylases are used in biofuel industries to break starch to fermentable sugar [5,6]. Amylases are used in the production of fruit juices and cakes, in brewing and baking and other processed foods [6].…”