Fermenting agricultural biomass, such as rice straw (RS), to methane is a promising solution to an ongoing waste problem. However, the biomass must first be pretreated to break down lignin thereby increasing accessibility of the substrate to fermentative organisms. Biological pretreatment by microorganisms represents a potentially economical strategy to prepare the biomass for fermentation. We isolated seven candidate ligninolytic Bacillus sp. strains based on their robustness for lignin degradation. The production of the ligninolytic enzymes from these strains was characterized and optimized. The bacterial strains were tested for their ability to pretreat RS and increase the yield of biomethane fermentation. It was determined that using mixed combinations of bacterial cultures was more effective than using individual strains. Overall, the study demonstrates the potential of using these Bacillus sp. strains as robust biocatalysts for processing lignocellulosic waste biomass. Significance: Newly isolated Bacillus sp. strains demonstrated an efficient degradation of lignin, Azure B dye, fast hydrolysis of rice straw, and improved biogas yields. This research suggests that, Bacillus sp. strains could be a source of novel enzymes, and an ideal candidate in bioprocessing of complex substrates”. © 2018 American Institute of Chemical Engineers Environ Prog, 38:e13036, 2019

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Starch is added to the fabric surface to secure weaving process. During finishing these sized particles are removed from the fabric and prepared it for printing and dyeing. Chemicals de-sizing agents damage fabric surfaces and reduce the quality of the product. An alternative to these conventional desizing agents is the use of biological molecules i.e. enzymes. The current study compares traditional de-sizing to bio-based de-sizing methods, as well as the optimization of fabric desizing settings using crude amylase. Amylase-producing Bacillus cereus AS2 was isolated from indigenous soil samples. The maximal fermentative de-sizing capability was discovered at 72 h, with no fabric surface degradation. Chemical desizing showed that the fabric lost all sizing agents to TEGEWA scale 9 within 1 h in presence of 5N HCl. Optimal studies for desizing showed that 1000 IU/ml of amylase resulted in maximum de-sizing within 15 h at 60 °C and 0.5% Triton-X. Water absorbance and weight loss, both parameters were used to check the desizing efficacy and it was found that de-sizing to same scale was occurred in the case of enzyme as well as commercially desized fabric. Enzyme desized cloth was found to be free of any starch particles in SEM micrographs, identical to industrially de-sized fabric, ensuring bioprocess efficacy.