Evaluation of cadmium tolerance and remediated efficacy of wild and mutated Enterobacter species isolated from potassium nitrate (KNO3) processing unit contaminated soil.

The purpose of this study was to find the most cadmium (Cd2+) tolerant and remediated bacteria isolate from KNO3 processing unit contaminated soil. One isolate out of 19 isolates possessed excellent Cd2+ tolerance than others, which was recognized as Enterobacter hormaechei SFC3 through molecular characterization (16S rRNA sequencing). The identified E. hormaechei SFC3 contained 55% and 45% of GC and AT content, respectively. The wild and acridine orange mutated E. hormaechei SFC3 exhibited excellent resistance to Cd2+ up to the concentration of 1500 µg mL-1. Furthermore, the wild E. hormaechei SFC3 and mutated E. hormaechei SFC3 showed 82.47% and 90.21% of Cd2+ remediation on 6th days of treatment respectively. Similarly, the Cd2+ tolerant wild and mutated E. hormaechei SFC3 showed considerable resistance to all the tested antibiotics. The findings indicate that E. hormaechei SFC3 isolated from KNO3 processing unit contaminated soil is a promising candidate for microbial remediation of Cd2+ contamination.

Synthesis of AgNPs from leaf extract of Naringi crenulata and evaluation of its antibacterial activity against multidrug resistant bacteria.

The biosynthesis of AgNPs using a methanolic extract of Naringi crenulata is described in this study. UV-visible spectroscopy, X-ray diffraction (XRD), Energy dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FTIR), particle size analyzer (PSA), scanning electron microscope (SEM), atomic force microscopy (AFM), and transmission electron microscopy (TEM) were used to characterize the synthesized AgNPs. The UV-visible spectrum revealed a sharp peak at 420 nm, which represents silver's strong Plasmon resonance. FTIR and XRD confirmed the functional groups (N-H stretch, alkanes, O-H stretch, carboxylic acid, N-H bend, C-X fluoride, and C-N stretch) and face-centered cubic crystalline structure of synthesized AgNPs. SEM and TEM analyses revealed that the synthesized nanoparticles had a spherical morphology with an average diameter of 32.75 nm. The synthesized AgNPs have antibacterial activity against multidrug-resistant bacteria pathogens such as Vibrio cholerae, Staphylococcus aureus, Streptococcus pyogenes, Escherichia coli, and Klebsiella pneumoniae. AgNPs can be synthesized using a methanolic extract of Naringi crenulate, and the resulting particle may have wide range of biological applications.