Identification of Streptomyces strains isolated from Humulus lupulus rhizosphere and determination of plant growth promotion potential of selected strains.

In the present study it was aimed to obtain novel strains of actinomycetes that have the ability to promote plant growth. For this, seven soil samples from the rhizosphere of Humulus lupulus (Pazaryeri, Bilecik) were used and potential isolates were obtained. 16S rRNA genes of 30 isolates were amplified by PCR and sequenced. Eighteen isolates were found to be closely related to Streptomycetes spp. and they were tested for their proteolytic activity, cellulase activity, phosphate solubility, IAA production, biofilm formation, and growth in nitrogen-limited medium. Two isolates, HCI 12 and HCI 36, were selected according to the results of these tests and their effects on growth of tomato plants (Solanum lycopersicum) were determined. Results indicated that the HCI 12 and HCI 36 strains caused a significant increase in root and shoot lengths, dry/fresh weights, and vigor index values compared to the control. The change in macromolecular structure including carbohydrates, proteins, and lipids of tomato plants with HCI 12 and HCI 36 inoculation was determined by Fourier transform infrared (FTIR) analysis. The results obtained from FTIR analysis were used in principal component analysis to evaluate changes in amide, carbohydrate, and lipid ratios of plant leaves due to microorganism application. Inoculation with the HCI 12 and HCI 36 strains caused a significant increase in the total carbohydrate and lipid ratio of tomato.

Kribbella sindirgiensis sp. nov. isolated from soil.

A Kribbella strain FSN23T was isolated from soil sample which was collected from Caygoren Dam lakeside located in Sindirgi, Turkey. The isolate was investigated using a polyphasic approach consisting of numeric, chemotaxonomic and molecular analysis. The isolate indicated chemotaxonomic, morphological and phylogenetic properties associated with members of the genus Kribbella. Phylogenetic analysis based on the 16S rRNA sequence of the strain demonstrated that the strain forms a subclade with K. aluminosa HKI 0478T and K. jejuensis HD9T. The organism formed an extensively branched substrate and aerial hyphae which generated spiral chains of spores with smooth surfaces. The cell wall contained LL-diaminopimelic acid, and the whole cell sugars were glucose and ribose along with trace amounts of mannose. The polar lipids were identified as phosphatidylglycerol, diphosphatidylglycerol, four unidentified lipids and five unidentified polar lipids. The predominant menaquinone was MK-9(H4). The major cellular fatty acids were anteiso-C15:0 and iso-C16:0. Polyphasic taxonomy properties confirm that strain FSN23T represents a novel Kribbella taxon distinguished from closely related type strains. Hence, strain FSN23T (=KCTC 29220T = DSM 27082T) is proposed as the type strain of a novel species with the name Kribbella sindirgiensis sp. nov.

Kribbella soli sp. nov., isolated from soil.

A novel actinobacterial strain, designated FMN22T, was isolated from soil and characterised using a polyphasic approach. Strain FMN22T showed high 16S rRNA gene sequence similarity to Kribbella karoonensis Q41T (99.3%), Kribbella shirazensis UTMC 693T (99.0%), Kribbella aluminosa HKI 0478T (98.9%) and Kribbella hippodromi S1.4T (98.6%). Phylogenetic analysis using the 16S rRNA and concatenated gene (gyrB, rpoB, relA, recA and atpD) sequences showed that strain FMN22T is closely related to the type strains of K. karoonensis DSM 17344T, K. shirazensis UTMC 693T, K. aluminosa HKI 0478T, K. hippodromi S1.4T, Kribbella jejuensis HD9T and Kribbella solani DSA1T. Based on concatenated gene genetic distances analysis, strain FMN22T is distinct from all Kribbella type strains. DNA-DNA hybridization experiments with closely related type strains, were found to be 59.2 ± 2.4, 54.8 ± 2.1, 16.4 ± 2.3 and 38.6 ± 2.5%, relatedness to K. karoonensis DSM 17344T, K. shirazensis DSM 45490T, K. aluminosa DSM 18824T and K. jejuensis DSM 17305T, respectively. The cell wall peptidoglycan contained LL-diaminopimelic acid, and whole cell sugars were glucose, mannose and ribose. The predominant menaquinone was MK-9(H4). The major phospholipids are diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine and phosphatidylinositol. Major fatty acids are anteiso-C15:0 and iso-C16:0. These chemotaxonomic traits are in good agreement with those known for representatives of the genus Kribbella. A combination of DNA-DNA hybridization results and phenotypic properties demonstrated that strain FMN22T can be clearly distinguished from all close phylogenetic relatives. Therefore, strain FMN22T (=DSM 27132T = KCTC 29219T) is considered to be the type strain of a novel species of the genus Kribbella, for which the name Kribbella soli is proposed.

Nocardia zapadnayensis sp. nov., isolated from soil.

A novel Gram-stain positive, rod-shaped, non-motile and mycolic acid containing strain, FMN18(T), isolated from soil, was characterised using a polyphasic approach. The organism showed a combination of morphological, biochemical, physiological and chemotaxonomic properties that were consistent with its classification in the genus Nocardia and it formed a phyletic line in the Nocardia 16S rRNA gene tree. The cell wall contained meso-diaminopimelic acid (type IV) and whole cell sugars were galactose, glucose, arabinose and ribose. The predominant menaquinone was MK-8(H4ω-cyclo). The major phospholipids are diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol and phosphatidylinositol mannosides. Major fatty acids are C16:0, 10-methyl C18:0 (TBSA), C18:1 cis9 and C16:1 trans9. These chemotaxonomic traits are in good agreement with those known for representatives of the genus Nocardia. The phylogenetic analysis based on the 16S rRNA gene sequence of strain FMN18(T) showed it to be closely related to Nocardia grenadensis GW5-5797(T) (99.2 %), Nocardia speluncae N2-11(T) (99.1 %), Nocardia jinanensis 04-5195(T) (99.0 %) and Nocardia rhamnosiphila 202GMO(T) (98.3 %). The phylogenetic analysis based on the gyrB gene sequence of strain FMN18(T) showed it to be closely related to N. rhamnosiphila 202GMO(T) (99.0 %), N. grenadensis DSM 45869(T) (96.6 %), N. jinanensis DSM 45048(T) (93.1 %), N. carnea IFM 0237(T) (89.7 %) and N. speluncae DSM 45078(T) (89.1 %). A combination of DNA-DNA hybridization results and phenotypic properties demonstrated that strain FMN18(T) was clearly distinguished from all closely related Nocardia species. It is proposed that the organism be classified as representing a novel species of the genus Nocardia, for which the name Nocardia zapadnayensis (type strain FMN18(T) = DSM 45872(T) = KCTC 29234(T)) is proposed.

Nonomuraea muscovyensis sp. nov., isolated from soil.

A novel actinomycete, strain FMN03(T), was isolated from a soil sample collected from Yuga Zapadnaya South-West Forest Park, Moscow, Russia. The isolate had chemical and morphological properties typical of members of the genus Nonomuraea and formed a distinct 16S rRNA gene subclade with the type strains Nonomuraea roseoviolacea subsp. carminata NBRC 15903(T) and Nonomuraea roseoviolacea subsp. roseoviolacea NBRC 14098(T). The organism formed extensively branched substrate and aerial hyphae, which generated spiral chains of spores with smooth surfaces. The cell wall contained meso-diaminopimelic acid and the whole cell sugars were glucose, galactose and trace amounts of madurose, mannose and xylose. The polar lipids were phosphatidylethanolamine, hydroxyphosphatidylethanolamine, four unidentified phospholipids, four unidentified glycolipids and one unidentified lipid. The predominant menaquinone was MK-9(H4). The major fatty acids were iso-C16 : 0 2-OH, C17 : 0 10-methyl, C17 : 1 cis9 and iso-C16 : 0. Analyses of its morphological, physiological and biochemical characteristics, together with DNA-DNA relatedness data, confirmed that strain FMN03(T) is a representative of a novel species of the genus Nonomuraea, which is distinct from closely related reference strains. Strain FMN03(T) ( = DSM 45913(T) = KCTC 29233(T)) is proposed as the type strain of a novel species, for which the name Nonomuraea muscovyensis sp. nov. is proposed.

Antimicrobial activity screening of some sulfonamide derivatives on some Nocardia species and isolates.

Nocardia are aerobic, catalase-positive, Gram-positive microorganisms and typically acid-alcohol fast at some stage of the growth cycle. The genus Nocardia, a member of Mycolata group, is clinically important because it is an opportunistic pathogen. The sulfonamide derivative medicines are prefered to cure infection caused by Nocardia, such as nocardiaosis and mycetoma. Antimicrobial activities of seven sulfonamide derivatives have been investigated against some Nocardia species and isolates using the disk diffusion method on Sensitest agar medium (Oxoid). Thirty-six organisms, which consisted of 10 soil isolates selected from different clusters of Aymen study (2003), six clinical isolates provided by Ege University, Medical School, Microbiology and Clinical Microbiology Department, four reference strains, 15 type strains and a control strain of Staphylococcus aureus ATCC 43300 were tested. The strongest inhibition was observed in the cases of IV [N-(2-hydroxy-4-nitro-phenyl)-4-methyl-benzensulfonamid], V [N-(2-hydroxy-5-nitro-phenyl)-4-methyl-benzensulfonamid] and III [N-(2-Hydroxy-phenyl)-4-methyl-benzenesulfonamide] against Nocardia. Introducing a hydroxyl group into the ortho position on the ring increased the antimicrobial activity. Substitution of the electron withdrawing groups such as a nitro group increased the antimicrobial activity remarkably.