Environmental monitoring and assessment of antibacterial metabolite producing actinobacteria screened from marine sediments in south coastal regions of Karnataka, India

Abstract

Assessment of the therapeutic potential of secondary metabolite producing microorganisms from the marine coastal areas imparts scope and application in the field of environmental monitoring. The present study aims to screen metabolites with antibacterial potential from actionbacteria associated with marine sediments collected from south coastal regions of Karnataka, India. The actinobacteria were isolated and characterized from marine sediments by standard protocol. The metabolites were extracted, and antibacterial potential was analyzed against eight hospital associated bacteria. The selected metabolites were partially characterized by proximate analysis, SDS-PAGE, and FTIR-spectroscopy. The antibiogram of the test clinical isolates revealed that they were emerged as multidrug-resistant strains (P ≤ 0.05). Among six actinobacteria (IS1-1S6) screened, 100 μl metabolite from IS1 showed significant antibacterial activities against all the clinical isolates except Pseudomonas aeruginosa. IS2 demonstrated antimicrobial potential towards Proteus mirabilis, Streptococcus pyogenes, and Escherichia coli. The metabolite from IS3 showed activity against Strep. pyogenes and E. coli. The metabolites from IS4, IS5, and IS6 exhibited antimicrobial activities against Ps. aeruginosa (P ≤ 0.05). The two metabolites that depicted highest antibacterial activities against the test strains were suggested to be antimicrobial peptides with low molecular weight. These isolates were characterized and designated as Streptomyces sp. strain mangaluru01 and Streptomyces sp. mangaloreK01 by 16S ribosomal DNA (rDNA) sequencing. This study suggests that south coastal regions of Karnataka, India, are one of the richest sources of antibacterial metabolites producing actinobacteria and monitoring of these regions for therapeutic intervention plays profound role in healthcare management.

Effects of stocking density on the growth performance, physiological response and intestinal microbiota of juvenile Echiura worms ( Urechis unicinctus )

“…Therefore, a significant reduction was observed in the growth performance with progressively increasing stocking density. In the soil, Actinobacteria play an important role in the elimination of organic matter, as they can promote the decomposition of dead animal and plant remains (Skariyachan et al., 2017). Actinobacteria in the gut of earthworms have also been reported to be associated with lignocellulosic diets (Knapp, Podmirseg, Seeber, Meyer, & Insam, 2009).…”

Multiresistant Bacteria Isolated from Activated Sludge in Austria

“…In general MRSA isolates from surface water are rather rare, with only low number of analysed isolates. Therefore an estimation which of the three MRSA types is more dominant in water environment is difficult to make [ 15 , 16 , 42 , 43 ].…”

“…Although the population of Staphylococci flushed into the wastewater is high, the survival of Staphylococci in water environment seems to be much lower than that of Gram negative bacilli. Therefore reports of MRSA from this reservoir are mainly restricted to areas of high human influence, e.g., hospital waste water effluent [ 15 , 16 , 17 ]. Vancomycin resistant Enterococci (VRE) are one of the first documented antibiotic resistant bacteria with primary origin in animal farming.…”

Microbial communities in sea cucumber (Apostichopus japonicus) culture pond and the effects of environmental factors

“…Actinobacteria promoted the decomposition of the remains of animals and plants in soil (Skariyachan et al, 2017). Although the aquaculture ponds in this study were investigated without feeding, there…”

“…Also, the abundance of Proteobacteria was correlated with nutrient content in water. In addition, Bacteroidetes and Actinobacteria also played a role in sewage treatment and nitrogen circulation in nature since Bacteroidetes was able to degrade organic pollutants (Mayer et al, ) while Actinobacteria promoted the decomposition of the remains of animals and plants in soil (Skariyachan et al, ). Although the aquaculture ponds in this study were investigated without feeding, there had been a large amount of feeds used years before and the ponds had not been cleaned up, for which there were residual feeds and excreta at the bottom of the ponds.…”