Inactivating pathogenic bacteria in greywater by biosynthesized Cu/Zn nanoparticles from secondary metabolite of Aspergillus iizukae; optimization, mechanism and techno economic analysis

Abstract

The inactivation of antibiotic resistant Escherichia coli (Gram negative) and Staphylococcus aureus (Gram positive) seeded in greywater by bimetallic bio-nanoparticles was optimized by using response surface methodology (RSM). The bimetallic nanoparticles (Cu/Zn NPs) were synthesized in secondary metabolite of a novel fungal strain identified as Aspergillus iizukae EAN605 grown in pumpkin medium. Cu/Zn NPs were very effective for inhibiting growth of E. coli and S. aureus. The maximum inactivation was optimized with 0.028 mg mL-1 of Cu/Zn NPs, at pH 6 and after 60 min, at which the reduction of E. coli and S. aureus was 5.6 vs. 5.3 and 5.2 vs. 5.4 log reduction for actual and predicted values, respectively. The inactivation mechanism was described based on the analysis of untreated and treated bacterial cells by Field emission scanning electron microscopy (FESEM), Energy Dispersive X-Ray Spectroscopy (EDS), Atomic Force Microscopy (AFM) revealed a damage in the cell wall structure due to the effect of Cu/Zn NPs. Moreover, the Raman Spectroscopy showed that the Cu/Zn NPs led to degradation of carbohydrates and amino structures on the bacteria cell wall. The Fourier transform infrared spectroscopy (FTIR) analysis confirmed that the destruction take place in the C-C bond of the functional groups available in the bacterial cell wall. The techno economic analysis revealed that the biosynthesis Cu/Zn NPs is economically feasible. These findings demonstrated that Cu/Zn NPs can effectively inhibit pathogenic bacteria in the greywater.

Unveiling the role of novel biogenic functionalized CuFe hybrid nanocomposites in boosting anticancer, antimicrobial and biosorption activities

“…This may have enabled FCFNCs to target microorganism at numerous sites simultaneously and exerting more than a microbicidal mode of action. Likewise, Noman et al 36 discussed similar finding.…”

“…These results agreed with He et al 33 and Pandharipande and Makode 35 . In general, in view of internuclear vibrations, the metal oxide absorption peaks were observed at a lower field in range the 400–700 cm −1 , which reflected the metallic nature of any examined sample 7 , 12 , 36 . However, small shift in the absorption peaks was observed in FCFNCs profile which may be due to the interaction between CuNPs and FeNPs and also the association of FCFNCs with carboxylic acids in the protein, which led to functionalization and dispersion of FCFNCs as implied by Ismail et al 6 .…”

“…The second reason is the microbial cell concentration and microbial cell characteristics (physiologically and biochemically) which definitely differ not only among various microbial genera, but also among the related species 40 , 47 , 66 . The third parameter was the nature of the inactivation process which included the properties of application conditions and the medium in which NPs were applied, including, pH, contact time and organic/inorganic nutrients content of the medium as explained by Pinto et al 13 and Noman et al 36 . Various combinations of all such factors could accelerate or delay the microbial inactivation process and vary its effectiveness.…”

Survival and Disinfection of Sars-Cov-2 in Environment and Contaminated Surface

“…Since fungi have high binding capacity, tolerance and metal bio-accumulation ability and the intracellular intake they are utilized to synthesize metallic NPs. Synthesis of NPs by fungi is more 10 beneficial compared to other microorganisms as fungi are easy to isolate and culture grow faster than bacteria and easy to handle and produce in the laboratory [15].…”

“…In contrast, the application of nanotechnology in the wastewater treatment has been reported in the literature [14]. Noman et al [15] investigated the inactivation of antibiotic-resistant Escherichia coli…”