Significance of microbial genome in environmental remediation.

Environmental pollutants seriously threaten the ecosystem and health of various life forms, particularly with the rapid industrialization and emerging population. Conventionally physical and chemical strategies are being opted for the removal of these pollutants. Bioremediation, through several advancements, has been a boon to combat the existing threat faced today. Microbes with enzymes degrade various pollutants and utilize them as a carbon and energy source. With the existing demand and through several research explorations, Genetically Engineered Microorganisms (GEMs) have paved to be a successful approach to abate pollution through bioremediation. The genome of the microbe determines its biodegradative nature. Thus, methods including pure culture techniques and metagenomics are used for analyzing the genome of microbes, which provides information about catabolic genes. The information obtained along with the aid of biotechnology helps to construct GEMs that are cost-effective and safer thereby exhibiting higher degradation of pollutants. The present review focuses on the role of microbes in the degradation of environmental pollutants, role of evolution in habitat and adaptation of microbes, microbial degenerative genes, their pathways, and the efficacy of recombinant DNA (rDNA) technology for creating GEMs for bioremediation. The present review also provides a gist of existing GEMs for bioremediation and their limitations, thereby providing a future scope of implementation of these GEMs for a sustainable environment.

Electrospun nanofibers of polyvinylidene fluoride incorporated with titanium nanotubes for purifying air with bacterial contamination.

Polyvinylidene fluoride (PVDF) blended with varying concentrations of titanium nanotubes (TNT) was electrospun to result in a nanocomposite filter media. Sandwich structures were obtained by depositing the electrospun fibers between polypropylene (PP) nonwoven sheets. The synthesized tubular TNT was confirmed for its morphology through a transmission electron microscope (TEM). The prepared filter media was analyzed through a scanning electron microscope (SEM), X-ray diffraction (XRD), Fourier infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). The effectiveness of the filter media was evaluated through the zone of inhibition and antibacterial activity against E. coli and S. aureus. The Box-Behnken design is experimented with three-level variables, namely areal density of substrate (GSM), electrospinning time (hours), and concentration of TNT (wt%) for investigating the bacterial filtration efficiency through an Andersen sampler. Among other statistical tests (STATs), PVDF + 15 wt% TNT has a bacterial filtration efficiency of 99.88% providing greater potentials upon application for clean air management. It can be noted that the future application of this formulation could be efficient filtration of other microbes and could be used in facemasks to industrial-scale air filters. Graphical abstract.

Nanocomposite membrane and microbial community analysis for improved performance in microbial fuel cell.

To improve the performance of a microbial fuel cell (MFC), four variations of sulphonated silicon dioxide (S-SiO2) was incorporated into sulphonated poly ether ether ketone (SPEEK) membranes. S-SiO2 was characterized by scanning electron microscopy (SEM), fourier transform infra-red spectroscopy (FTIR) and X-ray diffraction (XRD) to confirm morphological, physical and chemical characteristics. The prepared membranes were incorporated into a fabricated tubular MFC of 300 mL holding capacity. Membrane characterizations such as water uptake, ion exchange capacity (IEC) and proton conductivity were determined. The highest maximum output of 154 ±â€¯1.5 mW m-2 is produced by SPEEK +7.5 wt% S-SiO2 with an IEC of 1.82 ±â€¯0.08 meq g-1 and an oxygen mass transfer coefficient of 1.42 × 10-6 cm s-1. Microbial community studies show the prevalence of novel microbial strains with the predominance of 3 distinct phyla, namely Betaproteobacteria, Gammaproteobacteria and Firmicutes. The results suggest that the prepared nanocomposite membrane proves to be an efficient and sustainable alternative for improving the performance of a MFC without abating the essential membrane characteristics.

Sulphonated polyhedral oligomeric silsesquioxane/sulphonated poly ether ether ketone nanocomposite membranes for microbial fuel cell: Insights to the miniatures involved.

In this study we demonstrate Sulphonated Polyhedral oligomeric silsesquioxane (S-POSS) incorporated Sulphonated Poly Ether Ether Ketone (SPEEK) as an effective cation exchange membrane (CEM) for improving performance and sustainability in a fabricated tubular Microbial Fuel Cell (MFC). The organic-inorganic caged frame of S-POSS enables several ion conducting channels thereby resulting in better proton conductivity and water uptake in addition to hydroxide ions native in POSS. Among the membranes, SPEEK+ 5 wt% S-POSS exhibits a highest maximum performance of 162 ± 1.4 mW m-2 with the highest IEC of 1.8 ± 0.05 meq g-1. Microbial community analysis reveals the predominance of several bacterial strains contributing to wide range of mechanisms. Three phyla including Betaproteobacteria, Gammaproteobacteria and Firmicutes showed maximum predominance. In addition to a novel nanocomposite membrane, the present research introduces perceptions of two metabolic mechanisms of the microbial community available which opens pathway for future insights on how other miniatures involve in electron transfer mechanisms.