Biosynthesis of Zinc Nanoparticles From Actinobacterium Streptomyces Species and Their Biological Potential

In today's world, antibiotic-resistant microorganisms are a major concern. There is solid evidence that metal nanoparticles (NPs) tend to have antimicrobial properties. The most effective substitute for antibiotic resistance is the incorporation of metal NPs. The antibacterial properties of NPs are currently being explored and shown to be successful. Zinc (Zn) NPs that are biosynthesized from marine Actinobacterium proved to be more biocompatible, bioactive, and affordable.  Aim: This study aims to investigate the synthesis of ZnNPs from Actinobacterium Streptomyces species and their antimicrobial effects against gram-positive and gram-negative bacteria.

The current study uses natural, considerably safer processes to synthesize ZnNPs from marine Actinobacteria with little to no negative side effects. It involves sample collection, identification, and isolation of Actinobacterium Streptomyces species. The isolated sample was air-dried, and extracts of ZnNPs were taken. Among the isolates from marine sediment, two Actinobacteria that generate bioactive secondary metabolites-Streptomyces species (MOSEL-ME28) and Rhodococcus rhodochrous (MOSEL-ME29)-were selected for extracellular synthesis of ZnNPs. The antimicrobial activity of the biosynthesized ZnNPs from marine Actinobacteria was analyzed against Staphylococcus (MRSA), Klebsiella pneumoniae, and Streptococcus mutans. The results were statistically analyzed and graphs were created.

ZnNPs obtained from Actinobacterium Streptomyces species exhibited antimicrobial effects against Staphylococcus (MRSA), Klebsiella, and Streptococcus mutans. At 280 nm wavelength, analysis of the UV spectrum showed a notable absorbance value of 1.8. The antibacterial efficacy against Staphylococcus MRSA, Klebsiella species, and Streptococcus mutans was assessed by measuring the zone of inhibition in diameter. The zones of inhibition were 8, 8, and 7 mm on the evaluation for Streptococcus mutans, S. aureus, and Klebsiella species, respectively, at a dose of 75 μg/mL. When the dosage was increased to 100 μg/mL, the inhibition zones were found to be 9.5, 9, and 7.5 mm for the respective bacterial strains.

ZnNPs are biosynthesized from marine Actinobacterium Streptomyces species in this research study. They have a significant antimicrobial activity against both gram-positive and negative bacteria. This indicates that ZnNPs have enormous antimicrobial potential and have an extensive spectrum of applications. However, clinical trials must be completed before it can be used safely on patients.