Screening and Isolation of antibiotic producing Actinomycetes from marine samples using rifampicin

摘要

The total number of actinomycetes recovered from different samples varied between a maximum of 3.5 x 10 super(5) CFU/gm of samples of sea weeds and algae to a minimum of 6.2x10 super(2) CFU/ml of sea water. A total of 132 strains of actinomycetes were isolated, of these 76 (57.6%) exhibit antimicrobial activity to one and/ or more of bacterial, filamentous fungi or yeast strains. Most of the inhibitory activity was directed against bacteria than filamentous fungi and yeast. Among bacterial group Bacillus subtilis (39.4%) was the most susceptible while Proteus vulgaris (11.4%) was the least. Among fungal strains, Penicillium chryseogenum (34.1%) was the most susceptible while Aspergillus oryzae (10.6%) was the least. Thirty five (26.5%) of the total isolates exhibited broad spectrum activity. The result showed that, better recovery of actinomycetes was observed using rifampicin than using naldixic acid. Therefore, in the search for screening and isolation of bioactive producing actinomycetes, rifampicin might be used as a better drug of choice than naldixic acid for suppressing and inhibiting growth of non-filamentous bacterial contaminants in marine samples.