Bioconversion of agricultural residues and waste to value added products

Agricultural activities at farm as well in processing industries generate vast amount of waste annually. The resulting residues are rich in nutrients and compounds with potential biological applications, therefore would entail exclusion from being termed as “waste.” Agricultural residues encompass residues like leaves, twigs, stalks, straw, etc., which are generated during farm activities while as industrial residues, are those residues which are generated during processing of agricultural products into valuable secondary products. If these residues traditionally burned or dumped to rot, they would accrue significant burden to environment by releasing greenhouse gases. Since, these residues are rich in sugar, nutrients, minerals, antioxidants, carbohydrates, enzymes, and proteins, biotransformation of these residues can generate a myriad of usable products. Bioconversion of residues would also ensure reduced burden of handling the imbalance incurred to ecosystem caused due to rampant dumping and burning of these wastes causing air & environmental pollution. A number of studies have been conducted to convert different residues like cereal residues, fruit and vegetable residues, sugar industry residues, oil crop residues and industrial residues to useful by-products such as antimicrobial compounds, biodiesel, biogas, antibiotics, organic substrates for mushroom cultivation or production of xanthan, tempeh, sugar or amino acid syrups, etc. Carbohydrases, proteases, esterases and lipases, hemicellulases, and cellulases are some of the important enzymes that find tremendous application in biotransformation of wastes to valuable products.