Klanbut, Khanungkan

Loading...
Thumbnail Image
Preferred name
Klanbut, Khanungkan
Main Affiliation
Email
khanungkan.kl@kmitl.ac.th

Settings

Now showing 1 - 2 of 2
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Publication,
    Streptomyces tyrfis sp. nov., an actinobacterium isolated from Thai peat swamp forest soil and its promising secondary metabolites
    (2026-12-01)
    Kottip, Penkawee
    ;
    Klanbut, Khanungkan
    ;
    Fukasem, Poowadon
    ;
    Pittayakhajonwut, Pattama
    ;
    Intaraudom, Chakapong
    An actinomycete strain, PTD5-9<sup>T</sup>, was isolated from peat swamp forest soil in Narathiwat Province, Thailand. Chemotaxonomic features and phylogenetic analysis based on the 16S rRNA gene sequence placed this strain within the genus Streptomyces. It exhibited the highest sequence similarity to Streptomyces gelaticus NRRL B-2928ᵀ (99.38%) and Streptomyces sanglieri NBRC 100784ᵀ (99.31%). However, the average nucleotide identity based on MUMmer (ANIm) values (88.48–88.56%), the average amino acid identity (84.37–84.97%), and digital DNA–DNA hybridization (dDDH) estimates (31.2–36.5%) were significantly below the accepted thresholds for species demarcation, supporting its classification as a new species within the genus. Accordingly, the name Streptomyces tyrfis sp. nov. is proposed. The crude extract derived from the culture broth of strain PTD5-9ᵀ exhibited potent antibacterial activity against Gram-positive bacteria (MIC ≤ 250 µg/mL). Subsequent chemical analysis led to the identification of ten bioactive secondary metabolites: isocycloheximide (1), (2R,4S,6E)-anhydrocycloheximide (2), actiphenol (3), (−)-phenatic acid A (4), 8-O-methyltetrangomycin (5), 8-O-methylrabelomycin (6), 4-hydroxy-8-O-methylrabelomycin (7), tetrangulol methyl ether (also known as X-14881 E) (8), (−)-elmonin (9), and 2-phenylacetamide (10). Among these, compounds 3, 6, 7, and 8, which were isolated in sufficient quantities, exhibited notable inhibitory activity against Mycobacterium tuberculosis, with MIC values ranging from 3.13 to 25.0 µg/mL. Furthermore, compounds 6, 7, and 8 demonstrated pronounced cytotoxicity against human small cell lung cancer (NCI-H187) cells (IC₅₀: 1.10–7.80 µM), and against human breast cancer (MCF-7) cells (IC₅₀: 1.21–24.6 µM).
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Publication,
    Streptomyces salinarius sp. nov., an actinomycete isolated from solar saltern soil
    (2023-01-01)
    Klanbut, Khanungkan
    ;
    Rattanakavil, Thitiya
    ;
    Duangupama, Thitikorn
    ;
    Suriyachadkun, Chanwit
    ;
    Herron, Paul Robert
    An actinobacterium, designated strain SS06011<sup>T</sup>, was isolated from solar saltern soil collected from Samut Sakhon province, Thailand. The taxonomic position of this strain was established using the polyphasic taxonomic approach. The strain produced grey aerial spore mass on International Streptomyces Project 2 seawater agar that differentiated into spiral spore chains with rugose-surfaced spores. Strain SS06011<sup>T</sup> was found to have ll-diaminopimelic acid in the cell peptidoglycan. Whole-cell hydrolysates contained galactose, glucose and ribose. MK-9(H<inf>6</inf> ) and MK-9(H<inf>4</inf> ) were major menaquinones. The major cellular fatty acids comprised iso-C<inf>16: 0</inf>, anteiso-C<inf>15: 0</inf> and anteiso-C<inf>17: 0</inf> . Diphosphatidylglycerol, phosphatidylethanolamine, phosphatidyl-glycerol and phosphatidylinositol were detected in cells. These characteristics were coincident with the typical morphological and chemotaxonomic properties of the genus Streptomyces. The taxonomic affiliation at the genus level of this strain could also be confirmed by its 16S rRNA gene sequence data. Strain SS06011<sup>T</sup> showed the highest 16S rRNA gene sequence similarity to Streptomyces ardesiacus NRRL B-1773<sup>T</sup> (99.1 %), Streptomyces coelicoflavus NBRC 15399<sup>T</sup> (99.1 %) and Streptomyces hyderabadensis OU-40<sup>T</sup> (99.1 %). Digital DNA–DNA hybridization (dDDH), average nucleotide identity-blast (ANIb) and average amino acid identity (AAI) values between strain SS06011<sup>T</sup> and its closely related type strains, S. ardesiacus NBRC 15402<sup>T</sup>, S. coe-licoflavus NBRC 15399<sup>T</sup> and S. hyderabadensis JCM 17657<sup>T</sup>, were in the range of 45.4–48.4 % (for dDDH), 90.8–91.9 % (for ANIb) and 90.8–91.7 % (for AAI), respectively, which are lower than the cut-off criteria for species delineation. The DNA G+C content of genomic DNA was 71.9 mol%. With the differences in physiological, biochemical and genotypic data, strain SS06011<sup>T</sup> could be discriminated from its closest neighbours. Thus, strain SS06011<sup>T</sup> should be recognized as representing a novel species of the genus Streptomyces, for which the name Streptomyces salinarius sp. nov. is proposed. The type strain is SS06011<sup>T</sup> (=TBRC 9951<sup>T</sup>=NBRC 113998<sup>T</sup>).