The current research work illustrates an economical and rapid approach towards the biogenic synthesis of silver nanoparticles using aqueous Punica granatum leaves extract (PGL-AgNPs). The optimization of major parameters involved in the biosynthesis process was done using Box-Behnken Design (BBD). The effects of different independent variables (parameters), namely concentration of AgNO₃, temperature and ratio of extract to AgNO_3, on response viz. particle size and polydispersity index were analyzed. As a result of experiment designing, 17 reactions were generated, which were further validated experimentally. The statistical and mathematical approaches were employed on these reactions in order to interpret the relationship between the factors and responses. The biosynthesized nanoparticles were initially characterized by UV-vis spectrophotometry followed by physicochemical analysis for determination of particle size, polydispersity index and zeta potential via dynamic light scattering (DLS), SEM and EDX studies. Moreover, the determination of the functional group present in the leaves extract and PGL-AgNPs was done by FTIR. Antibacterial and antibiofilm efficacies of PGL-AgNPs against Gram-positive and Gram-negative bacteria were further determined. The physicochemical studies suggested that PGL-AgNPs were round in shape and of ~37.5 nm in size with uniform distribution. Our studies suggested that PGL-AgNPs exhibit potent antibacterial and antibiofilm properties.

Nanoparticles have gained immense interest as probable drug molecules against microbial infections. Metal nanoparticles synthesized via exploring the reduction potential and capping activity of plants were found to have remarkable antimicrobial activity. The synthesis was conducted without hazardous chemicals and generation of toxic waste products. The focus of the study was, therefore, to investigate the efficacy of silver nanoparticles biosynthesized using Grewia tenax leaf extract as an antibacterial, antibiofilm, and antifungal therapeutic agent. The silver nanoparticles (GTAgNPs) were synthesized using optimized conditions of 2.5mM AgNO₃ and 1:10 ratio of 10 extract at 37C on continuous stirring. The characterization was done by UV-visible spectroscopy, DLS, SEM, zeta potential, and FTIR. The antibacterial activity of GTAgNPs against both Gram (+) Bacillus cereus and Staphylococcus aureus and Gram () Escherichia coli and Pseudomonas aeruginosa bacteria via zone of inhibition, MIC, and MBC was analysed. The inhibitory effect of silver nanoparticles on biofilm formation was also observed against these bacteria. These nanoparticles were then evaluated for their potential antifungal activity against Candida albicans and Aspergillus niger by observing fungal growth inhibition. The probable mechanism of antimicrobial activity by GTAgNPs was studied by scanning electron microscopy which showed the significant formation of pores on the cell surface in GTAgNPs-treated microbial cells, leading to the death of the microbial cell. All these studies concluded that GTAgNPs possess the potent antimicrobial potential and can be employed as antimicrobial therapeutic agents.

Genome availability has made possible to compare the codon and amino acid usage strategies among different extremophiles. Correspondence analysis was used to characterise various patterns present in 200 genes encoding 10 key enzymes of citric acid cycle from 20 organisms surviving at varying temperature. The study has shown that the different extremophiles follow a specific trend of codon usage and amino acid composition which is affected by temperature variation and base composition which is vital for functional and structural stability of enzymes and hence for their adaptive survival in such harsh environmental conditions. It was found that higher temperature favours high aromaticity score which can be linked to its thermal behaviour. The results and statistical analysis of various parameters of codon usage shows a level of preference in synonymous codons and indicates towards a kind of anonymous selection pressure which help stabilising the genetic material at varying degree of temperature.