Isolation and characterization of pectinase-producing bacteria from fruit and vegetable soil

BACKGROUND AND OBJECTIVESPectinolytic bacteria are a type of bacteria that can break down pectin, a complex polysaccharide that forms a vital component of plant cell walls. These bacteria secrete enzymes called pectinases that facilitate the efficient degradation of pectin into smaller molecules. Pectinase can be found in fungi and bacteria. Pectinases play a crucial role in fruit juice extraction and the modification of food product texture.MATERIALS AND METHODSSoil samples were collected from decaying fruits, including apples, oranges, potatoes, and vegetables. The samples were suspended in nutrient broth medium and inoculated onto nutrient agar. The cultures were incubated overnight either at RT, ۳۷℃ and/or ۴℃. After observing the morphology of colonies, they were sub-cultured onto other nutrient media to isolate individual colonies. Then, morphological and microscopic characteristics of isolates were analyzed. To test their pectinolytic activity, we transferred them to pectin agar media containing only pectin as a carbon source. After incubation, a diluted solution of iodine-potassium iodide was applied to determine the size of the clear zone that surrounded the colonies.RESULTS AND DISCUSSIONFrom soil samples, ۲۰ pure isolates were obtained and characterized. It was revealed that out of the total isolates, twelve colonies were gram-positive while eight were gram-negative. Additionally, ۱۲ isolates were found in round-shaped cocci and ۸ isolates were in the form of rod-shaped bacilli. All ۲۰ isolates were grown on a pectin agar medium. Upon adding diluted iodine-potassium iodide solution to the medium and observing the clear zone formed around the colonies, five isolates represented the highest pectinolytic activity and were chosen for further investigation.CONCLUSIONIdentifying isolates with high pectinolytic activity is crucial for various industries that rely on pectinase enzyme production. Therefore, a thorough study is needed identify potential sources. We have isolated and characterized the pectinase-producing bacteria with higher pectinase activity and subjected to further molecular identification, characterization, and optimization.

کلیدواژه ها:

Industrial enzymes ، Pectinolytic bacteria ، Pectinase ، Pectin ، Iodine-potassium iodide