No abstract

A novel Gram-positive, aerobic, actinobacterial strain, CF5/4(T), was isolated in 2007 during an environmental screening of arid desert soil in Ouré Cassoni, Chad. The isolate grew best in a temperature range of 28-40 °C and at pH 6.0-8.5, with 0-1 % (w/v) NaCl, forming brown-coloured and nearly circular colonies on GYM agar. Chemotaxonomic and molecular characteristics of the isolate matched those described for members of the genus Geodermatophilus. The DNA G + C content of the novel strain was 75.9 mol %. The peptidoglycan contained meso-diaminopimelic acid as diagnostic diaminoacid. The main phospholipids were phosphatidylethanolamine, phosphatidylcholine, phosphatidylinositol, diphosphatidylglycerol and a small amount of phosphatidylglycerol; MK-9(H(4)) was identified as the dominant menaquinone and galactose as diagnostic sugar. The major cellular fatty acids were branched-chain saturated acids: iso-C(15:0) and iso-C(16:0). The 16S rRNA gene showed 96.2-98.3 % sequence identity with the three members of the genus Geodermatophilus: G. obscurus (96.2 %), G. ruber (96.5 %), and G. nigrescens (98.3 %). Based on the chemotaxonomic results, 16S rRNA gene sequence analysis and DNA-DNA hybridization with the type strain of G. nigrescens, the isolate is proposed to represent a novel species, Geodermatophilus arenarius (type strain CF5/4(T) = DSM 45418(T) = MTCC 11413(T) = CCUG 62763(T)).

A Gram-positive, spore-forming, aerobic, filamentous bacterium, strain JFMB-ATET, was isolated in 2008 during environmental screening of a plastic surface in grade C in a contract manufacturing organization in southern Germany. The isolate grew at temperatures of 25–50 °C and at pH 5.0–8.5, forming ivory-coloured colonies with sparse white aerial mycelia. Chemotaxonomic and molecular characteristics of the isolate matched those described for members of the family Thermoactinomycetaceae, except that the cell-wall peptidoglycan contained ll-diaminopimelic acid, while all previously described members of this family display this diagnostic diamino acid in meso-conformation. The DNA G+C content of the novel strain was 54.6 mol%, the main polar lipids were diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylglycerol, and the major menaquinone was MK-7. The major fatty acids had saturated C14–C16 branched chains. No diagnostic sugars were detected. Based on the chemotaxonomic results and 16S rRNA gene sequence analysis, the isolate is proposed to represent a novel genus and species, Kroppenstedtia eburnea gen. nov. sp. nov. The type strain is JFMB-ATET ( = DSM 45196T  = NRRL B-24804T  = CCUG 59226T).

A novel streptomycete, designated strain HM 35 T , was isolated from soil in Isfahan city, Iran. Strain HM 35 T produced a branched substrate mycelium and aerial hyphae that developed into short, compact, spiral spore chains with grey rugose spores at the tips of the aerial hyphae. On some media, these spirals coalesced into dark masses of spores with age. Whole-cell hydrolysates of strain HM 35 T contained LL-diaminopimelic acid, glucose and ribose. Phospholipids detected were phosphatidylglycerol, phosphatidylinositol, phosphatidylethanolamine, phosphatidylinositol mannosides, hydroxy-phosphatidylethanolamine, lyso-phosphatidylethanolamine and hydroxy-lyso-phosphatidylethanolamine. MK-9(H 4 ), ) and MK-9(H 8 ) were the predominant menaquinones. The major fatty acids were iso-and anteisobranched components. The chemotaxonomic characteristics of the novel isolate matched those described for members of the genus Streptomyces. Based on 16S rRNA gene sequence analysis, strain HM 35 T showed highest similarity to Streptomyces rapamycinicus NRRL 5491 T (99.2 %), Streptomyces violaceusniger DSM 40563 T (99.1 %), Streptomyces javensis DSM 41764 T (99.1 %) and Streptomyces yogyakartensis DSM 41766 T (99.1 %). The novel strain formed a distinct monophyletic line within the 16S rRNA gene sequence tree. The level of DNA-DNA relatedness between strain HM 35 T and the type strain of S. rapamycinicus was 72.7 %. Strain HM 35 T showed the typical morphology found among members of the S. violaceusniger/ Streptomyces hygroscopicus group but could be clearly differentiated from closely related species based on other phenotypic markers. Phenotypic and genotypic data thus indicate that strain HM 35 T represents a novel species of the genus Streptomyces, for which the name Streptomyces iranensis is proposed. The type strain is HM 35 T (5DSM 41954 T 5CCUG 57623 T ).The genus Streptomyces was proposed by Waksman & Henrici (1943) to accommodate aerobic, spore-forming actinomycetes. The genus comprises Gram-positive bacteria that have a high DNA G+C content (69-73 mol%), contain LL-diaminopimelic acid in the peptidoglycan and lack diagnostic sugars in whole-cell hydrolysates. More than 500 Streptomyces species have been described, the largest number of any bacterial genus (Euzéby, 2009). Although molecular systematic data show that the genus is clearly over-speciated (Lanoot et al., 2004), other polyphasic studies based on a combination of genotypic and phenotypic features continue to identify novel species and indicate that the genus Streptomyces as a whole is underspeciated (Kim & Goodfellow, 2002). Members of novel Streptomyces species are in demand as a source of new, commercially significant, bioactive compounds (Berdy, 1995;Fiedler et al., 2005).The Microbial Biotechnology Laboratory of the University of Tehran has been interested in isolating actinomycetes from Iranian soils, with the purpose of selecting strains with potential for biotechnological application.The aim of the present study was to classify a Streptomyceslike strai...

Three novel Gram-positive, aerobic, actinobacterial strains, CF5/2(T), CF5/1 and CF7/1, were isolated in 2007 during environmental screening of arid desert soil in the Sahara desert, Chad. Results from riboprinting, MALDI-TOF protein spectra and 16S rRNA sequence analysis confirmed that all three strains belonged to the same species. Phylogenetic analysis of 16S rRNA sequences with the strains' closest relatives indicated that they represented a distinct species. The three novel strains also shared a number of physiological and biochemical characteristics distinct from previously named Geodermatophilus species. The novel strains' peptidoglycan contained meso-diaminopimelic acid; their main phospholipids were phosphatidylcholine, phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylinositol and a small amount of phosphatidylglycerol; MK-9(H4) was the dominant menaquinone. The major cellular fatty acids were the branched-chain saturated acids iso-C16:0 and iso-C15:0. Galactose was detected as diagnostic sugar. Based on these chemotaxonomic results, 16S rRNA gene sequence analysis and DNA-DNA hybridization between strain CF5/2(T) and the type strains of Geodermatophilus saharensis, Geodermatophilus arenarius, Geodermatophilus nigrescens, Geodermatophilus telluris and Geodermatophilus siccatus, the isolates CF5/2(T), CF5/1 and CF7/1 are proposed to represent a novel species, Geodermatophilus tzadiensis, with type strain CF5/2(T)=DSM 45416=MTCC 11411 and two reference strains, CF5/1 (DSM 45415) and CF7/1 (DSM 45420).