In recent decades, the commercial production and industrial sector has experienced tremendous growth, yet this growth has also adversely impacted the environment's health. As a result, designing and developing environmentally friendly, clean, and green industrial technology has recently attracted much interest. In industrial manufacturing, enzymes (biocatalysts) are used instead of hazardous chemicals to develop environmentally benign processes. Enzyme-based industrial technology promises to utilize raw materials effectively, producing little to no waste and completely avoiding dangerous chemicals. The most common and renewable biomass found on Earth is lignocellulosic biomass. Efficient biodegradation necessitates the involvement of various hydrolytic enzyme types because of their intrinsic complexity and heterogeneity.
A novel Bacillus sp.PM06 isolated from sugarcane waste pressmud was tested for extracellular α-amylase and cellulase enzyme production. The effect of different substrates, nitrogen sources, pH, and temperature on growth and extracellular enzyme production was examined. The optimum pH and temperature were 5.5, at 50 °C for α-amylase and pH 6.4 at 60 °C for cellulase, respectively. The organism exhibited halotolerance up to 2 M NaCl and KCl and can saccharify and ferment all three different types of lignocellulosic biomass (wheat bran, sago waste, and rice bran) in submerged fermentation without pretreatment. It can produce both enzymes on all three agro wastes at pH levels ranging from 6 to 8 and 37–50 °C temperature ranges. Wheat bran was the most potent substrate and induced the maximum production of enzymes, and metabolites. Further, both enzymes were purified to homogeneity using anion exchange chromatography. The biochemical characterization of purified enzymes was examined. The combined action of both purified enzymes on agricultural waste resulted in the release of reducing sugar. The efficient breakdown of wheat bran by both enzymes is evident from the SEM study.
The novel isolates Bacillus sp. PM06 has the advantage of producing dual enzymes as it eliminates the need to add another organism or enzyme to improve hydrolysis, which eventually reduces the economics of the process. Our study is an effective approach to utilizing low-cost lignocellulosic substrates without pretreatment by a single novel Bacillus sp. PM06. Our research is unique because it takes a sustainable and environmentally friendly approach, producing renewable biofuels.
LIST OF PUBLICATIONS:
1. Rekha Rajesh, S.N. Gummadi (2020) α-amylase and cellulase production by novel halotolerant Bacillus sp.PM06 isolated from sugarcane pressmud. Biotechnology and Applied Biochemistry 69, 149-159. http://doi.org/ 10.1002/bab.2091.
2. Rekha Rajesh, S.N. Gummadi (2022) Production of multienzymes, bioethanol, and acetic acid by novel Bacillus sp. PM06 from various lignocellulosic biomass. Biomass Conversion and Biorefinery. https://doi.org/10.1007/s13399-022-02418-z.
3. Rekha Rajesh, S.N. Gummadi (2023) Purification and Biochemical characterization of novel α-amylase and cellulase produced by Bacillus sp. PM06 communicated.