MICROBIAL BIOCONVERSION OF TANNIC ACID TO GALLIC ACID BY Aspergillus flavus MW269654

The present study is developed to investigate the bioconversion of tannic acid to gallic acid by using Aspergillus flavus. It was isolated from a cultivated soil sample from Sharkia, Egypt and identified by 18srRNA as Aspergillus flavus MW269654. Advantages of bioconversion process including high yields, environmental safety and process reproducibility using biocatalyst have been well established over chemical technologies. Tannin acyl hydrolase, commonly known as tannase (EC 3.1.1.20) plays a major role in the bioconversion of hydrolysable tannins to produce gallic acid. This study suggested that tannic substances presented in agricultural wastes such as apple bagasse, green tea waste, pomegranates peel, groundnut shell, wheat bran, sugarcane bagasse, guava leaves, banana peel, rice bran, coffee powder and Coir pith, could potentially be utilized by low cost bioremediation systems using microbial cultures. Green tea as a carbon source was the optimum for higher gallic acid production and tannin degradation by A. flavus MW269654.The study also explained the immobilization of A. flavus MW269654 conidia using synthetic sponge, loofa sponge, corn stalk pulps, Agar-agar, Na-CMC and glue beads as conidia carriers. Whereas, conidia carried on synthetic sponge yield the highest amount of gallic acid followed by loofa cubic pieces. While glue beads showed the least for production of gallic acid.