Optimizing Production Conditions of a Caspian Sea Actinomycete Exhibiting Promising Antibacterial Activity Against...

Area of Science:

• Microbiology
• Marine Biotechnology
• Natural Products Chemistry

Background:

• Marine sediments are a rich source of microorganisms with potential therapeutic applications.
• Streptomyces sp. strain MN38, isolated from the Caspian Sea, was previously identified.
• Antibacterial agents from natural sources are crucial for combating drug-resistant pathogens.

Purpose of the Study:

• To characterize Streptomyces sp. strain MN38 from the Caspian Sea.
• To optimize the production of antibacterial agents from strain MN38 using statistical methods.
• To evaluate the antibacterial activity of the produced agent against Staphylococcus aureus and Enterococcus faecalis.

Main Methods:

• Strain MN38 was characterized using 16S rRNA analysis and morphological properties.
• A Two-factor Interaction/Minimum Run Resolution IV method was used for optimization.
• Antibacterial activity was assessed via the micro-dilution method against target bacteria.

Main Results:

• A statistically significant quadratic model identified optimal conditions for antibacterial production (P < 0.0001).
• Optimized conditions included specific nutrient concentrations (starch, yeast extract, peptone, KBr, CaCO3, sea salt, Fe2(SO4)3), temperature (28°C), incubation time (3 days), shaking speed (200 rpm), inoculum size (3.0% v/v), and pH (6).
• Enhanced antibacterial activity reached 69 Bu/ml against Staphylococcus aureus and 166 Bu/ml against Enterococcus faecalis.

Conclusions:

• Streptomyces sp. strain MN38 from Caspian Sea sediments is a potent producer of antimicrobial agents.
• Mathematical optimization significantly enhanced the production of these agents.
• The findings support the potential of marine natural products in pharmaceutical development.