Isolation and characterization of a collagenase-producing bacterium from the soil contaminated with slaughterhouse waste

Microbial enzymes have been considered extensively due to their low cost as well as suitable production and stability. Collagenases are proteolytic biocatalysts that have various applications in medicine, industry, and research. In this study, gelatinolytic bacteria were isolated from the soil contaminated with slaughterhouse waste. The isolate with the highest gelatin degradation activity was chosen and characterized with 16 S ribosomal DNA (rDNA) sequence via polymerase chain reaction (PCR) method. The selected isolate was tested for biochemical characteristics. Thereafter, the collagenase production in an industrial medium containing bone powder was investigated for 30 h with the selected bacterium. The enzyme molecular weight was determined using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) method, with the enzyme effect on the bone powder morphologically studied via scanning electron microscopy (SEM) analysis. The quantitative ninhydrin method and the qualitative zymography method were applied to measure the enzyme activity. The results indicated that enzyme production by the selected isolate reached its highest level after 25 h of cultivation. The enzyme with about 60 kDa molecular weight could efficiently degrade the collagen of bone powder.