In this paper, actinomycetes were isolated from vermicompost by tablet coating method. Antimicrobial activities of actinomycetes were measured by the agar block method. Strains with high activity were identified based on morphology and biochemical characteristics, as well as 16S rDNA gene sequence analysis. The results showed that 26 strains of actinomycetes were isolated, 16 of them had antimicrobial activities to the test strains which accounts for 61.54% of all strains. Among the 16 strains, the strain QYF12 and QYF22 had higher antimicrobial activity to Micrococcus luteus, with a formed inhibition zone of 27 mm and 31 mm, respectively. While the strain QYF26 had higher antimicrobial activity to Bacillus subtilis, and the inhibition zone diameter was 21 mm. Based on the identification of strains with high activity, the strain QYF12 was identified as Streptomyces chartreusis, the strain QYF22 was S. ossamyceticus and the strain QYF26 was S. gancidicus. This study provided a theoretical basis for further separate antibacterial product used for biological control.
Actinobacteria ; chemistry ; classification ; genetics ; isolation & purification ; Animals ; Anti-Bacterial Agents ; isolation & purification ; metabolism ; Bacteria ; drug effects ; Feces ; microbiology ; Molecular Sequence Data ; Oligochaeta ; Phylogeny ; Quality Control

Atopobium rimae, previously Lactobacillus rimae, is a strictly anaerobic, non-spore forming grampositive rod which was frequently isolated from odontogenic infection. We report a case of A. rimae bacteremia. A 47-yr-old man with liver cirrhosis was admitted to the hospital via emergency room due to fever and chill. His abdominal and pelvic computed tomography revealed a small abscess near the left adrenal gland. Three sets of blood cultures were taken and non-spore forming, grampositive rods were detected in all anaerobic vials. This isolate grew small nonhemolytic, gray-white translucent colonies on Brucella blood agar and was obligatory anaerobic on air-tolerance test. This organism was negative for catalase, indole, nitrate-reduction and beta-lactamase and failed to identify by Vitek ANI card (bioMerieux, France). 16S rRNA sequences of this showed 99.8% homology of the published sequence of A. rimae (GenBank accession number AF292371). Aspirates of periadrenal abscess grew Escherichia coli and Peptostreptococcus micros. He was treated with metronidazole and imipenem and follow-up cultures of blood were negative at days 4 and 10. To our knowledge, this is the first report of bacteremia of A. rimae.
*Actinobacteria/classification/genetics/isolation & purification ; Bacteremia/diagnosis/*microbiology/therapy ; Gram-Positive Bacterial Infections/diagnosis/*microbiology/therapy ; Humans ; Liver Cirrhosis/*complications ; Male ; Middle Aged ; Phylogeny ; RNA, Ribosomal, 16S/analysis ; Sequence Analysis, RNA

OBJECTIVETo isolate and indentify the promising antimicrobial metabolite producing Streptomyces strains from marine sediment samples from Andrapradesh coast of India.

METHODSAntagonistic actinomycetes were isolated by starch casein agar medium and modified nutrient agar medium with 1% glucose used as a base for primary screening. Significant antimicrobial metabolite producing strains were selected and identified by using biochemical and 16S rDNA level. Minimum inhibitory concentrations of the organic extracts were done by using broth micro dilution method.

RESULTSAmong the 210 actinomycetes, 64.3% exhibited activity against Gram positive bacteria, 48.5 % showed activity towards Gram negative bacteria, 38.8% exhibited both Gram positive and negative bacteria and 80.85 % isolates revealed significant antifungal activity. However, five isolates AP-5, AP-18, AP-41 and AP-70 showed significant antimicrobial activity. The analysis of cell wall hydrolysates showed the presence of LL-diaminopimelic acid and glycine in all the isolates. Sequencing analysis indicated that the isolates shared 98.5%-99.8% sequence identity to the 16S rDNA gene sequences of the Streptomyces taxons. The antimicrobial substances were extracted using hexane and ethyl acetate from spent medium in which strains were cultivated at 30°Cfor five days. The antimicrobial activity was assessed using broth micro dilution technique. Each of the culture extracts from these five strains showed a typical polyene-like property. The lowest minimum inhibitory concentrations of ethyl acetate extracts against Escherichia coli and Curvularia lunata were 67.5 and 125.0 µg/mL, respectively.

CONCLUSIONSIt can be concluded that hexane and ethyl acetate soluble extracellular products of novel isolates are effective against pathogenic bacteria and fungi.

Actinobacteria ; chemistry ; classification ; genetics ; isolation & purification ; Anti-Bacterial Agents ; chemistry ; pharmacology ; Anti-Infective Agents ; chemistry ; pharmacology ; Antifungal Agents ; chemistry ; pharmacology ; Bays ; Complex Mixtures ; chemistry ; pharmacology ; Geologic Sediments ; microbiology ; India ; Microbial Sensitivity Tests ; Molecular Sequence Data ; Phylogeny ; Polyenes ; chemistry ; pharmacology ; RNA, Ribosomal, 16S ; genetics