Microbial Bioconversion of Agro-Waste Biomass into Useful Phenolic Compounds

Abstract

There is amassive annual accumulation ofagro-industrial wastes that represent most of the vital energy resources. The major constituents of such wastes are cellulose and hemicellulose (75–80%) whereas lignin accounts for only 14%. Agricultural residues generated from every crop are of great concern following the problems of environmental pollution, recycling, utilization, and rural sanitation. At the same time, the accumulation results in the loss of a huge amount of potentially important materials. This has led to the concern of extracting useful residues to counterbalance the cost of treating and disposing of the wastes. Agro-industrial waste is greatly nutritious in nature 54and expedites microbial growth. Agricultural residues can thus be employed for the production of several value-added products, such as useful phenolic compounds. Agro-industrial wastes, such as rice bran, corn cob, and sugar cane bagasse, have been extensively scrutinized via diverse fermentation approaches for the production of phenolics. Most of these waste products are presently employed as animal feed, but the focus for generating rich value compounds from these trashes is being emphasized by several industrial as well as academic researchers. Biological degradation, for both economic as well as ecological aims, has turned out to be a progressively prevalent alternative for the treatment of industrial, agricultural, organic as well as toxic residues into several value-added products. Agricultural remains can be recycled both naturally as well as artificially by microorganisms. Aerobic microorganisms like bacteria, fungi, as well as some anaerobic organisms have exhibited potency to degrade major components of these residues. Several species of microorganisms are capable to degrade agro-waste residues into diverse value-added phenolic compounds. In recent times, there has been a growing interest to develop flavor production using biotechnological processes employing microorganisms. There exists a chemical resemblance between ferulic acid and vanillin following which the bioconversion of ferulic acid to vanillin was a study of interest. But for the production of “natural vanillin,” it is obligatory to utilize “natural ferulic acid” which can be extracted from raw materials by GRAS (Generally Regarded As Safe) enzymes.