Exopolygalacturonase Production from the Novel Strain Lichtheimia sp. UV-16 and Enzyme Hydrolysis Properties

Abstract

A pectinase-producing strain, Lichtheimia sp. X-8, was isolated from the soil for the first time. Subsequently, Lichtheimia sp. UV-16, with a 1.23-fold increase in pectinase activity, was obtained via UV mutagenesis, and optimization of its liquid fermentation process boosted pectinase activity from 455.6 ± 12.7 to 3202.0 ± 82.1 U/mL. The crude enzyme was purified by salting out and anion exchange resin, with a purification ratio of 2.28-fold and a yield of 36.5%. The optimal reaction temperature for the pure enzyme was 60 °C with an optimal pH of 5.5. Thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC) confirmed that the enzyme was an exopolygalacturonase, achieving over 99% efficiency in pectin hydrolysis. Furthermore, incorporating pure enzymes into juice pulps can substantially enhance the juice yield, which makes this polygalacturonase a promising application in the beverage industry.