Isolation and molecular identification of Bacillus cereus and Bacillus subtilis as pectinase-producing bacteria from various regions of Golestan province

Pectinases belong to the pectolytic enzymes which breakdown pectin polysaccharide present in plant tissues. Pectinase enzymes are the most widely used in food industries to produce fruit juice, tea, coffee, and oil. Bacteria are interesting sources in production of industrial enzymes. The aim of the present study was to isolate and molecular identify pectinase enzyme producing bacteria from soil. In this study, soil samples containing citrus peels were collected from some regions of Golestan province. The optimized pectin agar medium was used to isolate pectinase producing bacteria. Pectinase activity was indicated by the diameter of clear, hydrolyzed zones on the medium plates containing citrus pectin by adding Lugol's iodine. Bacterial isolates with higher pectinase activity were identified by 16S rRNA sequencing method. 20 out of 30 bacterial isolates revealed pectinase activity. All of the isolates were identified based on biochemical tests. Among them, 2 isolates had higher pectinase activity with regard to increase in the diameter of clear zone. Molecular studies indicated that the isolates were Bacillus cereus and Bacillus subtilis. In this study, two species of bacteria were introduced with suitable ability in pectinase production. Further studies are needed to assay the enzyme kinetics under a set of several constraints.