Biological synthesis of nanoparticles is a growing innovative approach that is relatively cheaper and more environmentally friendly than current physicochemical processes. Among various microorganisms, fungi have been found to be comparatively more efficient in the synthesis of nanomaterials. In this research work, extracellular mycosynthesis of silver nanoparticles (AgNPs) was probed by reacting the precursor salt of silver nitrate (AgNO₃) with culture filtrate of Aspergillus flavus. Initially, the mycosynthesis was regularly monitored by ultraviolet-visible spectroscopy, which showed AgNP peaks of around 400–470 nm. X-ray diffraction spectra revealed peaks of different intensities with respect to angle of diffractions (2θ) corresponding to varying configurations of AgNPs. Transmission electron micrographs further confirmed the formation of AgNPs in size ranging from 5–30 nm. Combined and individual antibacterial activities of the five conventional antibiotics and AgNPs were investigated against eight different multidrug-resistant bacterial species using the Kirby–Bauer disk-diffusion method. The decreasing order of antibacterial activity (zone of inhibition in mm) of antibiotics, AgNPs, and their conjugates against bacterial group (average) was; ciprofloxacin + AgNPs (23) > imipenem + AgNPs (21) > gentamycin + AgNPs (19) > vancomycin + AgNPs (16) > AgNPs (15) > imipenem (14) > trimethoprim + AgNPs (14) > ciprofloxacin (13) > gentamycin (11) > vancomycin (4) > trimethoprim (0). Overall, the synergistic effect of antibiotics and nanoparticles resulted in a 0.2–7.0 (average, 2.8) fold-area increase in antibacterial activity, which clearly revealed that nanoparticles can be effectively used in combination with antibiotics in order to improve their efficacy against various pathogenic microbes.

Globally, textile dyeing and manufacturing are one of the largest industrial units releasing huge amount of wastewater (WW) with refractory compounds such as dyes and pigments. Currently, wastewater treatment has been viewed as an industrial opportunity for rejuvenating fresh water resources and it is highly required in water stressed countries. This comprehensive review highlights an overall concept and in-depth knowledge on integrated, cost-effective cross-disciplinary solutions for domestic and industrial (textile dyes) WW and for harnessing renewable energy. This basic concept entails parallel or sequential modes of treating two chemically different WW i.e., domestic and industrial in the same system. In this case, contemporary advancement in MFC/MEC (METs) based systems towards Microbial-Electro-Fenton Technology (MEFT) revealed a substantial emerging scope and opportunity. Principally the said technology is based upon previously established anaerobic digestion and electro-chemical (photo/UV/Fenton) processes in the disciplines of microbial biotechnology and electro-chemistry. It holds an added advantage to all previously establish technologies in terms of treatment and energy efficiency, minimal toxicity and sludge waste, and environmental sustainable. This review typically described different dyes and their ultimate fate in environment and recently developed hierarchy of MEFS. It revealed detail mechanisms and degradation rate of dyes typically in cathodic Fenton system under batch and continuous modes of different MEF reactors. Moreover, it described cost-effectiveness of the said technology in terms of energy budget (production and consumption), and the limitations related to reactor fabrication cost and design for future upgradation to large scale application.

Background: Different concentrations of the simple carbon substrates i.e. glucose, fructose, and sucrose were tested to enhance the performance of the mediator-less double chamber microbial fuel cell (MFC). Objectives: The power generation potential of the different electron donors was studied using a mesophilic Fe (III) reducer and non-fermentative bacteria Pseudomonas aeruginosa-isolated from municipal wastewater. Materials and Methods: A double chamber MFC was operated with three different electron donors including glucose, sucrose, and fructose. Substrate utilization pattern was determined through chemical oxygen demand (COD) removal rate and voltage generation. In addition, electrochemical, physicochemical, and microscopic analysis of the anodic biofilm was conducted. Results:P. aeruginosa was proven to effectively utilize hexose and pentose sugars through anode respiration. Higher power density was generated from glucose (136 ± 87 mWm-²) lead by fructose (3.6 ± 1.6 mWm-²) and sucrose (8.606 ± mWm-²). Furthermore, a direct relation was demonstrated between current generation rate and COD removal efficiency. COD removal rates were, 88.5% ± 4.3%, 67.5% ± 2.6%, and 54.2% ± 1.9% with the three respective sugars in MFC. Scanning electron microscopy (SEM) demonstrated that the bacterial attachment was considerably abundant in glucose fed MFC than in the fructose and sucrose operated MFC. Conclusion: This study has revealed that electron donor type in the anodic compartment controls the growth of anodic biofilm or anode-respiring bacteria (ARB).