During a survey for natural-rubber-degrading actinobacteria associated with soils from Hevea brasiliensis plantations in Thailand, two strains, ABSL1-1 T and ABSL49-1 T , were isolated using mineral salts medium with natural rubber as the sole carbon source. Polyphasic taxonomy placed both strains within the genus Gordonia . Strain ABSL1-1 T showed the highest 16S rRNA gene sequence similarity to Gordonia otitidis NBRC 100426 T (98.5%) and Gordonia soli NBRC 108243 T (98.3%), while ABSL49-1 T showed the highest similarity to Gordonia polyisoprenivorans DSM 44302 T (98.4%). The digital DNA–DNA hybridization (dDDH) and average nucleotide identity based on blast values between ABSL1-1 T and closely related type strains were 20.1–20.9%, and 74.1–76.5%, respectively, while those for ABSL49-1 T and closely related type strains were 20.6–22.9%, and 74.3–79.1%, respectively. The cell-wall peptidoglycan of both strains contained meso -diaminopimelic acid and the whole-cell sugars comprised ribose, arabinose, galactose and glucose. Both strains contained MK-9(H 2 ) as the major menaquinone and phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol and phosphatidylinositol mannoside were detected as the polar lipids. The predominant fatty acids of ABSL1-1 T were C 16:0 , and C 18:1 ω 9c , while those for ABSL49-1 T were C 16:0 , C 18:1 ω 9c , summed feature 3 (C 16:1 ω 7 c/ C16:1 ω 6c ) and C 18:0 10-methyl. The G+C contents of the genomic DNA of strains ABSL1-1 T and ABSL49-1 T were 67.0 mol% and 66.0 mol%, respectively. Based on the results of a polyphasic taxonomic analysis, strains ABSL1-1ᵀ and ABSL49-1ᵀ represent the type strains of two novel species of the genus Gordonia , for which the names Gordonia heveisoli sp. nov. (type strain ABSL1-1ᵀ=TBRC 15892ᵀ=NBRC 116252ᵀ) and Gordonia gummivorans sp. nov. (type strain ABSL49-1ᵀ=TBRC 15624ᵀ=NBRC 115559ᵀ) are proposed.
Suriyachadkun et al. (Thu,) studied this question.