Amycolatopsis oliviviridis sp. nov., a novel polylactic acid-bioplastic-degrading actinomycete isolated from paddy soil.

A novel bioplastic-degrading actinomycete, strain SCM_MK2-4, was isolated from paddy soil in Thailand. The 16S rRNA gene sequence showed that strain SCM_MK2-4 belonged to the genus Amycolatopsis, with the highest sequence similarity to Amycolatopsisazurea JCM 3275 (99.4 %), and was phylogenetically clustered with this strain along with Amycolatopsislurida JCM 3141 (99.3 %), A. japonica DSM 44213 (99.2 %), A. decaplanina DSM 44594 (99.0 %), A. roodepoortensis M29 (98.9 %), A. keratiniphilasubsp. nogabecina DSM 44586 (98.8 %), A. keratiniphilasubsp. keratiniphila DSM 44409 (98.5 %), A. orientalis DSM 40040 (98.4 %) and A. regifaucium GY080 (98.3 %). A combination of DNA-DNA hybridization results ranging from 42.8±3.2 to 66.2±1.4 % with the type strains of A. azurea and A. lurida and some different phenotypic characteristics indicated that the strain could be distinguished from its closest phylogenetic neighbours. Whole-cell hydrolysates of the strain were shown to contain meso-diaminopimelic acid, arabinose, galactose, glucose, ribose, mannose, rhamnose and xylose. The predominant menaquinone was MK-9(H4). The major cellular fatty acid profile consisted of iso-C15 : 0, iso-C16 : 0, summed feature 3 (C16 : 1ω7c and/or iso-C15 : 0 2OH) and C16 : 0. The polar lipid composition of the strain consisted of phosphatidyl-N-methylethylethanolamine, phosphatidylethanolamine, hydroxyphosphatidylethanolamine, phosphatidylglycerol, aminophospholipids, an unidentified phospholipid and two unidentified glycolipids. The G+C content of the genomic DNA was 68.2 mol%. On the basis of phylogenetic analyses, DNA-DNA hybridization experimentation and the phenotypic characteristics, it was concluded that strain SCM_MK2-4 represents a novel species of the genus Amycolatopsis, for which the name Amycolatopsis oliviviridis sp. nov. is proposed. The type strain is SCM_MK2-4 (=TBRC 7186=JCM 32134).