ABSTRACT
A novel actinomycete strain was isolated from a soil sample collected in Japan by using gellan gum as a solidifying agent. Spore-chains from the short sporophores were straight and each had more than 20 spores per chain. Spores possessed no motility. Cell-wall peptidoglycan contained meso-diaminopimelic acid, glycine, alanine and glutamic acid; whole-cell hydrolysates contained arabinose, galactose and xylose. The acyl type of the peptidoglycan was glycolyl. The predominant menaquinones were MK-10(H(4)) and MK-10(H(6)); MK-10(H(8)) was a minor component. Mycolic acids were not detected. The diagostic phospholipid was phosphatidylethanolamine. Cellular fatty acids included heptadecenoic (C(17 : 1)), 14-methylpentadecanoic (i-C(16 : 0)) and octadecenoic (C(18 : 1)) acids. The G+C content of the DNA was 70 mol%. On the basis of morphogical and chemotaxonomic properties and phylogenetic analysis based on 16S rDNA sequence data, it is proposed that this strain should be classified in a novel genus and species, Longispora albida gen. nov., sp. nov., in the family MICROMONOSPORACEAE: The type strain is K97-0003(T) (=NRRL B-24201(T)=JCM 11711(T)).
Subject(s)
Micromonosporaceae/classification , Base Composition , DNA, Bacterial/chemistry , DNA, Bacterial/genetics , DNA, Ribosomal/genetics , Fatty Acids/analysis , Japan , Micromonosporaceae/genetics , Micromonosporaceae/isolation & purification , Micromonosporaceae/metabolism , Microscopy, Electron, Scanning , Molecular Sequence Data , Peptidoglycan/chemistry , Phenotype , Phylogeny , RNA, Bacterial/genetics , RNA, Ribosomal, 16S/genetics , Soil MicrobiologyABSTRACT
Species of the genus Streptomyces are of major pharmaceutical interest because they synthesize a variety of bioactive secondary metabolites. We have determined the complete nucleotide sequence of the linear chromosome of Streptomyces avermitilis. S. avermitilis produces avermectins, a group of antiparasitic agents used in human and veterinary medicine. The genome contains 9,025,608 bases (average GC content, 70.7%) and encodes at least 7,574 potential open reading frames (ORFs). Thirty-five percent of the ORFs (2,664) constitute 721 paralogous families. Thirty gene clusters related to secondary metabolite biosynthesis were identified, corresponding to 6.6% of the genome. Comparison with Streptomyces coelicolor A3(2) revealed that an internal 6.5-Mb region in the S. avermitilis genome was highly conserved with respect to gene order and content, and contained all known essential genes but showed perfectly asymmetric structure at the oriC center. In contrast, the terminal regions were not conserved and preferentially contained nonessential genes.
