Multi-enzyme-producing extremophile isolated from food waste under fluctuating environmental conditions

Abstract

Well-adapted bacteria under wide extreme conditions of acidic/alkaline pH and hot/cold temperatures play a significant role in degradation efficiency and in eliminating the cost of waste treatment processes in large areas. Extremozymes isolated by these organisms are resistant to extraordinary properties of salt allowance, cold adaptivity, and thermostability. In this study, we aimed to assess the isolation of protease-, amylase-, cellulase-, and lignin peroxidase-producing bacteria using a wide range of physical parameters to select suitable isolates and investigate their functions and enzyme activities. The bacterial strain FW2 was isolated from food waste and screened the growth and the degradation of organic compounds under fluctuating temperatures, different pH values, and high salinity concentrations. This strain was able to degrade organic compounds at temperatures from –6℃ to 75°C (weak at 80°C) under a wide pH range of 4.5–12, and in a sodium chloride (NaCl) concentration of 0–35%. Maximum enzyme production was obtained at 1200 U/mL for protease, 2400 U mL-1 for amylase, 920 U/mL for CMCase, 1300 U/mL for Avicelase, and 0.165 U/mL for Lignin peroxidase at pH 7–7.5, 40–45°C, and 0–10% NaCl. With these valuable characteristics, strain FW2 may be a potential contributor to waste degradation under fluctuating environmental conditions.