Langkah Sembiring

The Streptomyces violaceusniger clade: a home for streptomycetes with rugose ornamented spores

The taxonomic status of 16 strains received as Streptomyces hygroscopicus, Streptomyces melanosporofaciens, Streptomyces sparsogenes, Streptomyces sporoclivatus and Streptomyces violaceusniger was evaluated in a polyphasic study. Eleven of the organisms formed a distinct clade in the Streptomyces 16S rRNA gene tree with the type strains of Streptomyces asiaticus, Streptomyces cangkringensis, Streptomyces indonesiensis, Streptomyces javensis, Streptomyces malaysiensis, Streptomyces rhizosphaericus, Streptomyces yatensis and Streptomyces yogyakartensis, the members of this group produced rugose ornamented spores in spiral spore chains. The eleven strains were assigned to three established and four novel species, namely Streptomyces albiflaviniger sp. nov., Streptomyces demainii sp. nov., Streptomyces geldanamycininus sp. nov., Streptomyces griseiniger sp. nov., and Streptomyces hygroscopicus, Streptomyces melanosporofaciens and Streptomyces violaceusniger. It is also proposed that S. sporoclivatus becomes a subjective synonym of S. melanosporofaciens. S. sparsogenes NRRL 2940T, which produced ridged ornamented spores in spiral spore chains, formed a distinct phyletic line in the Streptomyces 16S rRNA gene tree and was readily distinguished from the other strains using a range of phenotypic properties. S. violaceusniger strains NRRL 8097, NRRL B-5799, NRRL 2834 and ISP 5182 fell outside the S. violaceusniger 16S rRNA gene clade and formed either smooth or ridged ornamented spores in either flexuous or spiral spore chains. These organisms were distinguished from one another and from their closest phylogenetic neighbors and were considered to merit species status as Streptomyces auratus sp. nov., Streptomyces phaeoluteichromatogenes sp. nov., Streptomyces phaeogriseichromatogenes sp. nov., and Streptomyces phaeoluteigriseus sp. nov., respectively.

Diversity of heavy metal resistant bacteria from Kalimas Surabaya: A phylogenetic taxonomy approach

Bacterial resistance to heavy metal is a genetic and physiological adaptation to the environment which contaminated by heavy metal. Kalimas is an important river in Surabaya that is contaminated by some heavy metals and probably as a habitat for heavy metal resistance bacteria. Bacterial resistance to heavy metals are different for each species, and their diversity can be studied by phylogenetic taxonomy approach. Isolates screening was done using nutrient agar which contained 1 mg/L HgCl2, CdCl2 and K2Cr2O7. Bacterial viability were observed by nutrient broth which contained 10 mg/L HgCl2, 30 mg/L CdCl2 and 50 mg/L K2Cr2O7. Isolates that resistant to heavy metal and viable after exposure to heavy metal were identified using 16S rRNA gene marker by Polymerase Chain Reaction (PCR). Phylogenetic tree reconstruction was done by the neighbor-joining algorithm. Genetic assignment showed isolates that resist and viable after exposure of Hg, Cd and Cr are Bacillus S1, SS19 and DA11. Based on BLAST analysis from ...

Metabolic profiling of endophytic bacteria from Purwoceng (Pimpinella pruatjan Molkend) root and antibacterial activity against Staphylococcus aureus and Pseudomonas aeruginosa

Recent study on antibiotic produced by endophytic bacteria become emerging to fight against the increasing of drug-resistant bacteria. Twenty eight isolates of endophytic bacteria from Purwoceng (Pimpinella pruatjan Molkend) have been screened for their potential in preventing growth of pathogens, including Staphylococcus aureus and Pseudomonas aeruginosa. In the present study four isolates (GP11, GP12, RP6 and DG1) and another three isolates (GP2, GP14 and DG1) showed the activity to prevent the growth of S. aureus and P. aeruginosa ATCC 27853, respectively. Bioactive compounds were extracted from culture broth using ethyl acetate, followed by Thin layer chromatography (TLC) for metabolic profiling to identify the chemical class of compounds. Taxonomic status of the isolates was determined by BLAST analysis based on 16S rRNA sequences. The result of inhibition zone from 500 mg · mL−1 crude extract DG1, GP11, GP12 and RP6 against S. aureus respectively are 0.78 cm, 1.18 cm, 0.95 cm and 1.2 cm, whereas for...