Nabya Nehal’s research while affiliated with Galgotias University and other places

Synthetic dyes and plastic items disposed from textile industries are a major cause of environmental pollution and seriously affect societal life. Many bioremediation techniques have been employed for the management of these polluting agents. In this study, Bacillus sp. MZ540316, Bacillus sp. MZ540327, and Brevibacillus borstelensis MZ562352 were isolated as new microbial strains from soil samples nearby textile effluents with potential of degradation of plastic and synthetic dyes. Bacillus sp. MZ540316 showed lower degree of decolorization effect against orange M2R dyes, fast green, rose bengal, and yellow M4G synthetic dyes. Among these isolates, Bacillus sp. MZ540316 and Bacillus sp. MZ540327 showed effective biodegradation of low-density polyethylene (LDPE, up to 29.67%) and high-density polyethylene (HDPE) pellets (up to 24.26%). The weight of LDPE pellets was reduced from 2.47 to 29.67% with decrease in surface tension by 34.07 mN/m. The maximum loss of weight percentage of HDPE pellets was observed up to 24.26% with decrease in surface tension by 34.23 mN/m. Brevibacillus borstelensis MZ562352 had degraded polyethylene at a lower rate by 4.84% for LDPE and 3.28% of HDPE films during 70 days of incubation period. These isolates had also showed high degree of biodegradation against different types of azo dyes. Bacillus sp. MZ540327 showed high level of decolorization (80–85%) against rose bengal dye and fast green dyes. Brevibacillus borstelensis MZ562352 had showed effective biodegradation (>85%) against all these synthetic dyes.

Fermentation technology has been widely used in biotechnology sectors for achieving large demand of industrially relevant biomolecules. Industries are facing major challenges for exploring novel method for increasing productivity of biomolecules at a very low cost. Nanodrug delivery systems have been used for target‐specific therapy due to their unique ability to increase solubility and bioavailability. Nanomaterial with excellent physiochemical nature and antimicrobial potential is used for crop protection, bioremediation, and food processing. But scientists are facing a major challenge for using low‐cost processing methods to create biocompatible and nontoxic nanodelivery systems. Nowadays, the integration of microbial fermentation process with nanotechnology are preferred for developing biocompatible, safe, and nontoxic nanostructures. In this book chapter, the role of microbial fermentation process for production of significant biomolecules has been highlighted. The integrated approach of this fermentation technology with nanotechnology has been subsequently discussed for improving productivity of industrially significant biomolecules.

Bacillus sp. MZ540316 was explored as new bacterial strain for production of lipopeptide biosurfactant with biodegradation efficiency against polyethylene polymers. In this study, the improved yield of biosurfactant was observed after optimizing its fermentative conditions using response surface methodology. The screening of significant nutrient media component was initially done by optimizing media components using classical methodology on the basis of emulsification index and surface tension. The optimum concentration for glucose, olive oil and yeast extract were obtained as 3 g/L, 2 g/L, and 1 g/L, respectively, after employing central composite design (CCD). This statistical methodology was further employed for estimation of optimum values for fermentative conditions with pH (7.5), fermentation period (4 days), agitation speed (150 rpm), temperature (35 °C), inoculum age (16 h), and inoculum size (2%). The yield of lipopeptide biosurfactant was improved with 1.42-fold higher after optimizing media component and culture condition. The suitable kinetic model was designed after studying growth kinetic and production kinetic profile under optimized fermentative conditions. The non-growth-associated behavior for production of biosurfactant would enable us to design mathematic model for cell growth kinetic and production kinetic using logistic equation and Luedeking-Piret equation, respectively. This isolate showed higher biodegradation efficiency against low density polyethylene polymer with maximum weight loss (14.33%) in compare to weight loss of high-density polyethylene pellets (10.86%).

Biologically synthesized surfactant are commercially used in various biotechnology sectors as cosmetic, cleaning, and agriculture products. In this study, Bacillus paramycoides was isolated as new bacterial strain from plastic disposal site of Banasthali Vidyapith (Rajasthan) for producing lipopeptide biosurfactant. Surface tension, emulsification index, oil-displacement are some primary screening methods done to validate the production of biosurfactant. The emulsification analysis elucidated at 62.50% and reduction of surface tension noticed at 33.10 mN/m. The nano-encapsulation of this biosurfactant onto silver nanoparticles had efficiently improved its ability for biodegradation of polyethylene. UV sterilized polyethylene films were treated with biosurfactant mediated silver nanoparticles and its maximum degradation was observed within 70 days. The synthesized silver nanoparticles were characterized by UV spectrum, zeta size potential, scanning electron microscope analysis. The total weight loss of low-density polyethylene (cling films) and high-density polyethylene (grocery bags) was observed 36.30% and 31.11%, respectively after treatment with silver nanoparticles for these lipopeptide biosurfactant. The higher degree of biodegradation rate of LDPE and HDPE polyethylene after treating with silver nano-biosurfactant might be due to their high degree of biocompatibility and stability. These nano-biosurfactant could be effectively used for biodegradation of plastic pollutant at large scale.