Abstract
A novel siderophore-producing actinomycete, designated PL19(T), was isolated from the Scotspine needle-like leaves collected from TNAU campus, Coimbatore, India. The isolate was chemoorganotrophic in nutrition and able to grow at 30 degrees C, and the optimum pH and NaCl facilitated the growth pH 6-11 and 0-8% (w/v), respectively. The cells are filamentous and the mycelia formed are basically of wide and intricately branched substrate mycelium from which aerial mycelia arises, later gets differentiated into spores that are warty and arranged spirally. The 16S rRNA gene of strain PL19(T) was sequenced and was highly similar to the type strains of species of the genus Streptomyces, including Streptomyces barkulensis RC1831(T) (98.8% pairwise similarity), Streptomyces fenghuangensis GIMN4.003(T) (98.2 %), Streptomyces nanhaiensis SCSIO 01248(T) (98.0 %), Streptomyces radiopugnans R97(T) (97.9 %), Streptomyces atacamensis C60(T) (97.8 %) and Streptomyces macrosporus NBRC 14749(T) (97.2 %), all of which were subjected to taxonomical characterization using a polyphasic approach. The strains showed unique carbon utilization patterns, and it possesses iso-C-16 : 0 anteiso-C-15 : 0 and anteiso-C-17 : 0 as a major cellular fatty acids. The cell-wall was dominated with LL-type diaminopimelic acid, and the menaquinone type was MK-9(H-6, H-8). These chemotaxonomic evidences placed strain PL19(T) within the genus Streptomyces. The determination of G+C ratio (69.5 mol%) and DNA-DNA hybridization values (13.4-31.8% with the phylogenetically related species) helped in further hierarchical classification of strain PL19(T). Based on morphological, physiological and chemotaxonomic data as well as DNA-DNA hybridization values, strain PL19(T) could be distinguished from the evolutionarily closest species currently available. All these collective data show that strain PL19(T) represents a novel species of the genus Streptomyces, for which the name Streptomyces pini sp. nov. is proposed. The type strain is PL19(T) (= NRRL B-24728(T) = ICMP 17783(T)).