Actinomadura violacea sp. Nov., a madurastatin a1-producing strain isolated from lichen in thailand

An actinomycete strain, LCR2-06^T, isolated from a lichen sample on rock collected from Chiang Rai Province (Pong Phra Bat Waterfall), Thailand, was characterized using a polyphasic approach. The strain grew at 25–45 °C, pH 6–11 and on International Streptomyces Project 2 agar plate with 5 % (w/v) NaCl. It contained meso-diaminopimelic acid as the diamino acid in whole-cell hydrolysates. Rhamnose, ribose, xylose, madurose, glucose and galactose were detected as whole-cell sugar hydrolysates. Mycolic acids were absent. The N-acyl type of muramic acid was acetyl. The strain contained C_{16: 0}, TBSA 10-methyl C_{18: 0} and 2-hydroxy C_{16: 0} as the predominant fatty acids and MK-9(H₆), MK-9(H₄) and MK-9(H₈) as the major menaquinones. The major polar lipids were diphosphatidylglycerol, phosphatidylinositol and unidentified phospholipid. The draft genome of strain LCR2-06^T was closely related to Actinomadura barringtoniae TBRC 7225^T (99.2 %), Actinomadura nitritigenes NBRC 15918^T (98.8 %), Acti-nomadura montaniterrae TISTR 2400^T (98.5 %) and Actinomadura physcomitrii JCM 33455^T (97.9 %). The draft genome of LCR2-06^T was 11.1 Mb with 10 588 coding sequences with an average G+C content of 72.7 mol%. Results of genomic analysis revealed that the ANIb and ANIm values between strain LCR2-06^T and A. montaniterrae TISTR 2400^T were 90.0 and 92.0 %, respectively. The digital DNA–DNA hybridization value was 43.9 % in comparison with the draft genome of A. montaniterrae TISTR 2400^T. The strain produced an antibacterial compound active against Bacillus subtilis ATCC 6633 and Kocuria rhizophila ATCC 9341. The results of taxonomic analysis suggested that strain LCR2-06^T represented a novel species of the genus Actinomadura for which the name Actinomadura violacea sp. nov. is proposed. The type strain is LCR2-06^T (=JCM 33065^T =KCTC 49547^T=NBRC 114810^T=LMG 32136^T=TISTR 2935^T).