The Pectinase Production Potential of Microorganisms Isolated from Agricultural Soil and Rotten Fruits in Shiraz, Southwest of Iran

Abstract

Pectinase is a general term for enzymes such as Pectoliase, Pectozyme, and Polygalactronase, which are usually considered Pectic enzymes. Pectinases are produced by plants and several microbial strains, including yeasts and bacteria. It is estimated that commercial Pectic enzymes from Bacillus spp. Make-up about 50% of the enzyme market. Raw fruit juices contain amounts of colloidal pectin. This substance can cause the precipitation of plant membranes during filtration and make it challenging to clarify fruit juice due to its fibril-like structure. Regarding the benefit of the production of commercial Pectinase from microorganisms, we aimed to investigate the profile of pectic enzymes producing microorganisms from agricultural soil and fruit in Shiraz, southwest of Iran. Actually, since there is a need for an enzyme that can break down Pectin in raw fruit juice, we conducted this study to comprehensively understand the Pectinase-producing microbial reservoir. For the isolation of Pectinase-producing microorganisms, agricultural soil samples were collected from Marvdasht and Bieza, Shiraz, Iran. Purified microbial isolates were stored at –80°C in a 20% glycerol concentration. After the primary characterization of Pectinase-producing isolates, the quantitative assay of Pectinase was done using Pectin as substrate. A total of 11 soil samples were mainly obtained. After purification, a total of 34 different microorganisms were isolated. Out of these, 26 (76.47%) isolates were from soil samples, and 8 (23.52%) ones from fruits. Based on morphological appearance and cultural characteristics, five isolates were related to the fungal cluster, and the rest were bacteria. The best producers were bacteria, followed by fungi. Based on the results of this study, it was determined that agricultural soil in Shiraz is a rich source of pectinase-producing gram-positive bacilli, which can be a rich source for commercial enzyme production.