RESUMO
Nanoparticles (NPs) are being recognized as antibacterial agents due to their rapidly increasing multidrug resistance in bacterial pathogens. Hence, there is an unmet need to identify the natural antibacterial agent. The present study aimed to evaluate the antibacterial activity of sericin-conjugated silver NPs synthesized by using sericin as a reducing and capping agent. Synthesized NPs were characterized by scanning electron microscope, nanolaser particle size analyzer (BT-90), Fourier-transform infrared analysis, and energy-dispersive X-ray. The biogenic NPs significantly inhibited the growth of Escherichia coli (12-15 mm zone of inhibition), Staphylococcus aureus (14.6-15.4 mm zone of inhibition), and Klebsiella pneumoniae (12.5-18 mm zone of inhibition). The stability of naturally synthesized NPs was examined at various temperatures (i.e., 4°C, 37°C, and 55°C) and pH (i.e., 3, 7, and 11). Temperature variability did not significantly affect the efficacy of NPs. However, NPs performed better at higher pH levels. This study suggested that the sericin-based silver NPs are not only effective against bacteria, but they also maintain the stability at different ranges of temperature and pH. We concluded that the sericin-conjugated silver NPs possess the remarkable antibacterial potential, which suggests their large-scale use as a cheap and stable antimicrobial agent in the future.
Assuntos
Antibacterianos/farmacologia , Nanopartículas Metálicas/química , Sericinas/química , Prata/química , Animais , Antibacterianos/química , Bactérias/classificação , Bactérias/efeitos dos fármacos , Bombyx , Estabilidade de Medicamentos , Concentração de Íons de Hidrogênio , Testes de Sensibilidade Microbiana , Nanoconjugados/química , Prata/farmacologia , TemperaturaRESUMO
The purpose of the current study was to document the variety of predatory spider species present in the cotton fields of two major cotton-producing districts in Punjab, Pakistan, as well as the population dynamics of those spiders. The research was carried out between May and October 2018 and 2019. Manual picking, visual counting, pitfall traps, and sweep netting were the procedures used to collect samples on a biweekly basis. A total of 10,684 spiders comprising 39 species, 28 genera, and 12 families were documented. Araneidae and Lycosidae families contributed a major share to the overall catch of spiders, accounting for 58.55 percent of the total. The Araneidae family's Neoscona theisi ) was the most dominating species, accounting for 12.80% of the total catch and being the dominant species. The estimated spider species diversity was 95%. Their densities were changed over time in the study, but they were highest in the second half of September and the first half of October of both years. The cluster analysis distinguished the two districts and the sites chosen. There was a relationship between humidity and rainfall and the active density of spiders; however, this association was not statistically significant. It is possible to increase the population of spiders in an area by reducing the number of activities detrimental to spiders and other useful arachnids. Spiders are considered effective agents of biological control throughout the world. The findings of the current study will help in the formulation of pest management techniques that can be implemented in cotton growing regions all over the world.
RESUMO
DNA barcoding is a new master key for species identification and has greatly accelerated the pace of species discovery. In this novel and cost-effective technique, a short DNA sequence from a standard region of mitochondrial "CO1" gene called "barcode" is used. At present, researchers all over the world are utilizing this powerful tool for investigating biodiversity, differentiating cryptic species, testing food authenticity, identifying parasites, vectors, insect pests, and predators, monitoring of illegal trade of animals and their products, and identifying forensically important insects. In addition, this technique can potentially be used to monitor quality of drinking water, quickly identify the indicator species of lakes, rivers, and streams, identify species with harmful attributes or medicinal properties, monitor smuggling of endangered plants and animals and their products, and disease investigations. Despite non-favorable criticism from a few researchers, DNA barcoding has achieved immense popularity in the scientific community, especially among biologists. The present review provides an overview of DNA barcoding and its practical applications. The limitation, future prospective and main informative platforms for DNA barcoding have also been discussed.