Utilization of agricultural waste biomass and recycling toward circular bioeconomy.

The major global concern on energy is focused on conventional fossil resources. The burning of fossil fuels is an origin of greenhouse gas emissions resulting in the utmost threat to the environment and subsequently which leads to global climate changes. As far as sustainability is concerned, fuels and materials derived from organic or plant wastes overcome this downside establishing the solution to the fossil resource crisis. In this context, exploration of agricultural residue appears to be a suitable alternative of non-renewable resources to support the environmental feasibility and meet the high energy crisis. The use of agricultural waste as a feedstock for the biorefinery approach emerges to be an eco-friendly process for the production of biofuel and value-added chemicals, intensifying energy security. Therefore, a prospective choice of this renewable biomass for the synthesis of green fuel and other green biochemicals comes up with a favorable outcome in terms of cost-effectiveness and sustainability. Exploiting different agricultural biomass and exploring various biomass conversion techniques, biorefinery generates bioenergy in a strategic way which eventually fits in a circular bioeconomy. Sources and production of agricultural waste are critically explained in this paper, which provides a path for further value addition by various technologies. Biorefinery solutions, along with a life cycle assessment of agricultural waste biomass toward a wide array of value-added products aiding the bioeconomy, are summarized in this paper.

Production of phenolic flavoring compounds from sugarcane bagasse by Lactobacillus acidophilus MTCC 10307.

The production of useful phenolic flavor compounds by utilizing Lactobacillus acidophilus MTCC 10307 was studied. Ferulic acid, vanillic acid and vanillin were obtained as the significant phenolic acids from the fermentation medium. The compounds were identified and quantified by high-performance thin-layer chromatography. The phenolic acids were detected for 15 days. A maximum quantity of ferulic acid was quantified on the 9th day of incubation and the quantity decreased on further incubation. While the utmost amounts of vanillic acid and vanillin were detected on the 12th day of incubation. The concentration of carbohydrates from the de-starched bagasse was also estimated and was contrasted with that of the original (control) bagasse. The growth pattern of the microorganism was also studied. The quantity of ferulic acid measured per kg of sugarcane bagasse on the 9th day of incubation was determined to be approximately 275 mg whereas 18 mg and 15 mg of vanillic acid and vanillin, respectively, were measured per kg of bagasse on the 12th day of incubation. Ferulic acid esterase was isolated and the fermentation conditions such as pH, temperature and incubation period were standardized for the maximum recovery of the enzyme. The results revealed that in optimized condition, ferulic acid esterase yield was found to be 2.2 U ml-1 at 35 °C, whereas ferulic acid esterase yield was 2.3 U ml-1 at 6.5 pH and 2.4 U ml-1 after 60 h of the incubation period.