Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Isolation of Streptomyces bacterial cultures for the induced production of antibiotics: a preliminary analysis Nick Kreutz, Catherine Gould, Alastair Pringle & Gabriel Colbeck Abstract Streptomyces bacteria are commonly found in soil and are well known for producing antibiotics. However, only about .1-.5% of all strains have been identified. Due to the high potential for producing valuable secondary metabolites, and the growing need for new, viable antibiotics, the isolation of novel strains of Streptomyces could be critically important. Here, we isolated several cultures of Streptomyces, however we failed to identify any antimicrobial properties. Methods -We collected soil from 6 locations in and around St. Louis, Missouri: Tower Grove Park, Oak Knoll Park, Maryville University, Maryville Co-op garden, Castlewood State Park, and Cliff Cave State Park -We isolated pure cultures of Streptomyces, then examined how these cultures affected growth of two test organisms: E.coli and S.aureus Methods (laboratory) -We treated soil with CaCO3 (10:1 w/w), and incubated at 370 C for 4 days -The mixture was suspended in ¼ strength Ringer Solution -a 1:100 dilution was prepared from this mixture -We placed dilution tubes in a 45oC water bath for 16 hrs -Then we inoculated the dilutions on Actinomycete Isolation Agar -Streptomyces identified and isolated for N=4 N=59 pure culture N=72 N=35 Results We were able to successfully isolate and culture samples of Streptomyces Field collection of soil samples (above/below) a)Cliff Cave Park b) Oak Knoll Park c) Maryville Line Streak Method Results Streptomyces isolate -Using sterile test tubes, we collected soil from the rhizosphere, ~20 cm deep Test Organism (E.coli) Test Organism (S.aureus) We streaked a single line (visible above) of Streptomyces down the middle of the plate. After waiting two days we streaked test organisms perpendicular to the isolate, but found the Streptomyces to overgrow the entire plate. This prevented the observation of any inhibition. Discussion We were able to isolate and characterize Streptomyces bacteria from three different locations. We did not observe the inhibition of test organisms, however it was noted the Streptomyces seemingly overgrew the test organisms. Future work will focus on: • Controlling Strep growth such that we can observe any potential antibiotic effects • Isolating and examining different cultures of Strep • Examining the conditions under which these newly isolated strains display the best growth and/or antimicrobial activity • Using genetic analysis to identify our strains (and/or the closes relatives of these strains) • Performing mutagenic analysis to try to produce mutants of these strains that will have stronger antimicrobial properties • Doing chemical analysis of the specific antimicrobial compounds Acknowledgements We would like to thank Dr. Postier and Jeff Carroll of their assistance with this project.