Isolation and molecular identification of polyphenol oxidase and associated enzyme production from Bacillus spp.

Abstract

Polyphenol oxidase (PPO) causes browning in food by converting phenolics to quinone, rendering unwanted organoleptic and nutritional changes. As a result, it represents a major problem in the food industry which must be addressed to reduce food waste and maximize food quality and shelf life despite PPOs importance in various industrial processes. The present study aimed to isolate Bacillus sp., evaluate their PPO production and related enzymes, and identify them through 16S rRNA sequencing. The selected strains isolated from soil were induced, and the cultures were grown OD600 of 1.0 (1x108 CFU) for evaluation. The study identified various types of Bacillus sp. as the source of PPO, tyrosinase and catecholase production. The data revealed that the strains Bacillus cereus, Bacillus albus, Bacillus subtilis, Bacillus thuringenesis and Bacillus tropicus exhibited PPO, tyrosinase and catecholase enzyme production with a maximum of 104.2 IU/ml, 68.61 IU/ml and 61.59 IU/ml respectively. Enzyme activity differed between organisms and substrate activities, which must be standardized. Despite the importance of PPO and related enzymes to browning reactions and food processing, there has been limited progress in this area. Therefore, taking a different approach to provoke more concerns is probably necessary.