Abstract
A total of six isolates of Actinomycetes were collected from marine sediments of Andaman Islands. Each isolate was tested against five pathogenic bacteria and also against some pathogenic fungi. Among the six isolates, one of the isolates showed potent activity against all the bacteria and fungi. These isolates appear to produce high anti-fungal and anti-bacterial compounds on potato dextrose agar and nutrient agar medium respectively, by using the agar diffusion method. The potent Actinomycetes were characterized by morphological methods consist of macroscopic and microscopic methods. The mycelium structure, color and arrangement of conidiophores were observed through the oil immersion (100X). Various biochemical tests performed for the identification of potent isolates are as follows: Melanin reaction, H2S production, tyrosine reaction, starch hydrolysis, casein hydrolysis, gelatin hydrolysis, milk coagulation and peptonization, nitrate reduction, temperature range of growth, pH tolerance and cell wall type by comparing all these results with the Bergey’s manual of Determinative Bacteriology and the organisms were identified. All the isolates were identified to belong to the genus Streptomyces. Further purification of the spent medium may gives more activity than the standard antibiotics and also effective against some multidrug resistant pathogens. Key words: Actinomycetes, Streptomyces, antimicrobial activity, pathogenic bacteria, pathogenic fungi, spent medium, secondary screening test
Highlights
Marine environments are largely untapped source for the isolation of new microorganisms with potentiality to produce active secondary metabolites
In the secondary screening test out of the five active isolates BC-1 isolate showed the potent activity against both bacterial and fungal organisms as shown in the Figures 4 and 5; zone of inhibitions of all active isolates are shown in Figures 6 and 7
Biochemical tests were performed in positive isolates of Actinomycetes and the results are shown in the Table 1
Summary
Marine environments are largely untapped source for the isolation of new microorganisms with potentiality to produce active secondary metabolites. Among such microorganisms, Actinomycetes are of special interest, since they are known to produce chemically diverse compounds with a wide range of biological activities (Bredholt et al, 2008). The demand for new antibiotics continues to grow due to the rapid emerging of multiple antibiotic resistant pathogens causing life threatening infection. Considerable progress is being made within the fields of chemical synthesis and engineered biosynthesis of antibacterial compounds, nature still remains the richest and the most versatile source for new
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
