Savitreea siamensis sp. nov., an ascomycetous yeast species in the family Saccharomycetaceae discovered in Thailand.

Four yeast strains, representing a novel anamorphic species, were isolated in Thailand. The two strains (ST-3660T and ST-3647) were obtained from two different estuarine water samples in a mangrove forest. Strain DMKU-FW1-37 was derived from a grease sample, and another strain (TSU57) was isolated from a fruiting body of Phallus sp. Pairwise sequence analysis showed that the four strains had identical or differed by only one nucleotide substitution in the D1/D2 domains of the large subunit (LSU) rRNA gene, and differed by one to three nucleotide substitutions in the internal transcribed spacer (ITS) regions. Savitreea pentosicarens is the most closely related species to the four strains, but with 9-10 (1.57-1.72 %) nucleotide substitutions in the D1/D2 domains of the LSU rRNA gene and 29-31 (4.22-4.45 %) nucleotide substitutions in the ITS regions. Phylogenetic analyses based on the concatenated sequences of the ITS regions and the D1/D2 domains of the LSU rRNA gene showed that the four strains form a well-separated lineage from S. pentosicarens with high bootstrap support, confirming that they represent a distinct species. Therefore, the four strains are assigned as representives of a novel species of the genus Savitreea, for which the name Savitreea siamensis sp. nov. is proposed. The holotype is TBRC 4481T and the ex-type is PYCC 9794T (=ST-3660T). The MycoBank number of the novel species is MB 851951.

Microbiome sequencing revealed the abundance of uncultured bacteria in the Phatthalung sago palm-growing soil.

Environmental variations have been observed to influence bacterial community composition, thereby impacting biological activities in the soil. Together, the information on bacterial functional groups in Phatthalung sago palm-growing soils remains limited. In this work, the core soil bacterial community in the Phatthalung sago palm-growing areas during both the summer and rainy seasons was examined using V3-V4 amplicon sequencing. Our findings demonstrated that the seasons had no significant effects on the alpha diversity, but the beta diversity of the community was influenced by seasonal variations. The bacteria in the phyla Acidobacteriota, Actinobacteriota, Chloroflexi, Methylomirabilota, Planctomycetota, and Proteobacteria were predominantly identified across the soil samples. Among these, 26 genera were classified as a core microbiome, mostly belonging to uncultured bacteria. Gene functions related to photorespiration and methanogenesis were enriched in both seasons. Genes related to aerobic chemoheterotrophy metabolisms and nitrogen fixation were more abundant in the rainy season soils, while, human pathogen pneumonia-related genes were overrepresented in the summer season. The investigation not only provides into the bacterial composition inherent to the sago palm-cultivated soil but also the gene functions during the shift in seasons.

Phylogenomic delineation of two new species of ascomycetous yeasts, Wickerhamiella koratensis sp. nov. and Wickerhamiella limtongiae sp. nov., and proposal of two synonyms, Wickerhamiella infanticola and Wickerhamiella tropicalis.

Two novel ascomycetous yeast species of the genus Wickerhamiella are proposed based on isolates obtained in Thailand from food waste and the fruiting body of a polypore fungus, and on a combination of conventional DNA-barcode sequence analyses and whole-genome phylogenies. We focus on a particular subclade of the genus Wickerhamiella that contains species found in anthropic environments and describe Wickerhamiella limtongiae sp. nov. (DMKU-FW31-5T=PYCC 9022T=TBRC 15055T), found on food waste samples. In an adjacent clade, we describe Wickerhamiella koratensis sp. nov. (DMKU-KO16T=PYCC 8908T=TBRC 14869T), which represents the closest relative of Wickerhamiella slavikovae and was isolated from the fruiting body of Bjerkandera sp. In the subclade of W. limtongiae sp. nov., we propose that Wickerhamiella infanticola should be regarded as a synonym of Wickerhamiella sorbophila and that Wickerhamiella tropicalis should be regarded as a synonym of Wickerhamiella verensis.

Lipase Production by Limtongozyma siamensis, a Novel Lipase Producer and Lipid Accumulating Yeast.

Lipase is a well-known and highly in-demand enzyme. During the last decade, several lipase optimization studies have been reported. However, production costs have always been a bottleneck for commercial-scale microbial enzyme production. This research aimed to optimize the conditions for lipase production by Limtongozyma siamensis DMKU-WBL1-3 via a One-Factor-At-a-Time (OFAT) approach combined with statistical methods while using a low-cost substrate. Results suggest that low-cost substrates can be substituted for all media components. An optimal medium was found, using response surface methodology (RSM) and central composite design (CCD), to consist of 0.50% (w/v) sweet whey, 0.40% (w/v) yeast extract (food grade), and 2.50% (v/v) palm oil with the medium pH adjusted to 4 under shaking flask cultivation. From an economic point of view, this work was successful in reducing production costs while increasing lipase productivity. The medium costs were reduced by 87.5% of the original cost while lipase activity was increased by nearly 6-fold. Moreover, lipase production was further studied in a 2-L stirred-tank fermentor. Its activity was 1,055.6 ± 0.0 U/ml when aeration and agitation rates were adjusted to 1 vvm and 170 rpm, respectively. Interestingly, under this optimal lipase production, the yeast showed accumulated lipids inside the cells. The primary fatty acid is a monounsaturated fatty acid (MUFA) that is typically linked to health benefits. This study hence reveals promising lipase production and lipid accumulation by L. siamensis DMKU-WBL1-3 that are worthy of further study.

Diversity of duckweed (Lemnaceae) associated yeasts and their plant growth promoting characteristics.

The diversity of duckweed (Lemnaceae) associated yeasts was studied using a culture-dependent method. A total of 252 yeast strains were isolated from 53 duckweed samples out of the 72 samples collected from 16 provinces in Thailand. Yeast identification was conducted based on the D1/D2 region of the large subunit (LSU) rRNA gene sequence analysis. It revealed that 55.2% and 44.8% yeast species were Ascomycota and Basidiomycota duckweed associated yeasts, respectively. Among all, Papiliotrema laurentii, a basidiomycetous yeast, was found as the most prevalent species showing a relative of frequency and frequency of occurrence of 21.8% and 25%, respectively. In this study, high diversity index values were shown, indicated by the Shannon-Wiener index (H'), Shannon equitability index (EH) and Simpson diversity index (1-D) values of 3.48, 0.86 and 0.96, respectively. The present results revealed that the yeast community on duckweed had increased species diversity, with evenness among species. Principal coordinate analysis (PCoA) revealed no marked differences in yeast communities among duckweed genera. The species accumulation curve showed that the observed species richness was lower than expected. Investigation of the plant growth promoting traits of the isolated yeast on duckweed revealed that 178 yeast strains produced indole-3-acetic acid (IAA) at levels ranging from 0.08-688.93 mg/L. Moreover, siderophore production and phosphate solubilization were also studied. One hundred and seventy-three yeast strains produced siderophores and exhibited siderophores that showed 0.94-2.55 activity units (AU). One hundred six yeast strains showed phosphate solubilization activity, expressed as solubilization efficiency (SE) units, in the range of 0.32-2.13 SE. This work indicates that duckweed associated yeast is a potential microbial resource that can be used for plant growth promotion.

Distribution of Kazachstania Yeast in Thai Traditional Fermented Fish (Plaa-Som) in Northeastern Thailand.

Thai traditional fermented fish products (Plaa-som) from four provinces (Ubon Ratchathani, Surin, Sisaket, and Khon Kaen) in the northeast part of Thailand were collected and analyzed to determine their salt content, total acidity, and pH. Yeasts in all samples were isolated and identified to the genus and species level based on sequence analysis of the D1/D2 of the large subunit (LSU) rRNA gene and the internal transcribed spacer (ITS) region. The results revealed that the salt content, total acidity, and pH values are in the range of 2.01-6.9%, 0.62-1.9%, and 4.4-6.57%, respectively. Moreover, 35 strains of yeast were isolated and identified as eight genera, namely Candida, Diutina, Filobasidium, Kazachstania, Pichia, Saccharomyces, Torulaspora, and Yarrowia with 17 species. The ascosporogenous yeast, Kazachstania, was the most dominant genus found and was widely distributed among the fermented food samples. In addition, a new strain of yeast, Kazachstania surinensis, was also discovered in Plaa-som samples. Thus, this study is the first to report the presence and wide distribution of these yeasts in fish fermentation products.

Kazachstania surinensis f.a., sp. nov., a novel yeast species isolated from Thai traditional fermented food.

Seven yeast strains (UBIF12-1, UBFB13-1, SRFS56-3, SRFS57-2, SKFS62-1, SKFS66-1 and SKFS67-1) representing a single anamorphic novel yeast species were isolated from traditional Thai fermented foods in Ubon Ratchathani, Surin and Sisaket in the northeast part of Thailand. The results of analysis of the sequences of the D1/D2 region of the large subunit (LSU) rRNA gene and the internal transcribed spacer (ITS) region indicated that the seven strains showed zero to one nucleotide substitutions in the sequences of the D1/D2 region of the LSU rRNA gene, and zero to four nucleotide substitutions in the ITS region. Kazachstania humilis CBS 5658T was the most closely-related species, but with 0.7-0.9% nucleotide substitutions in the D1/D2 region of the LSU rRNA gene, and 2.0-2.2% nucleotide substitution in the ITS region. The results of a phylogenetic analysis based on the concatenated ITS and D1/D2 regions confirmed that the seven strains represented a single species of the genus Kazachstania distinct from the other recognized species of the genus. Furthermore, the morphological, biochemical and physiological properties of the seven strains not only indicated that they represented members of the genus Kazachstania, but that they were separated from K. humilis and K. pseudohumilis, the two most closely related species in the phylogenetic tree. Therefore, the seven strains were identified as representing a novel species, for which we propose the name Kazachstania surinensis f.a., sp. nov. The holotype is TBRC 15053T (isotype: SRFS57-2 and PYCC 9021). The MycoBank number of the novel species is 841892.

Magnusiomyces siamensis sp. nov., a yeast-like fungus isolated from food waste.

Three yeast strains, DMKU-GTSP8-6, DMKU-GTSP8-14T and DMKU-JED8-73, were isolated from food waste in Thailand. Based on the phenotypic characteristics and sequence analysis of the D1/D2 domain of the large subunit (LSU) rRNA gene and the internal transcribed spacer (ITS) region, it was revealed that the three strains clustered with the Magnusiomyces/Saprochaete clade. These strains were distinguished from the closely related species Saprochaete quercus CBS 750.85, Magnusiomyces ovetensis CBS 192.55T, Magnusiomyces starmeri CBS 780.96T, Saprochaete chiloensis CBS 8187T and Magnusiomyces ingens CBS 517.90T by 11.4, 13.1, 11.9, 11.2 and 12.6 % sequence divergence in the D1/D2 domain and by 34.6, 34.5, 33.6, 33.2 and 34.9 % sequence divergence in the ITS region, respectively. The new species, which does not produce ascospores, is described as Magnusiomyces siamensis. The holotype of Magnusiomyces siamensis is TBRC 15056T, and the isotypes are DMKU-GTSP8-14T and PYCC 9023T.

New approach for screening of microorganisms from Arabica coffee processing for their ability to improve Arabica coffee flavor.

The purpose of this research was to isolate microorganisms from coffee fermentation processes and screen them for their potential to improve the flavor of Arabica coffee using a new approach that included pectin degradation ability and growth in mucilage broth. All of the studied microorganisms were isolated from 38 different samples of fresh coffee cherries, coffee mucilage and coffee pulp. A total of 262 microbial isolates were obtained and subjected to screening using pectinase screening agar medium for pectinolytic organisms. The results of the pectinase production test showed that 18 yeast isolates were found to produce pectinase that could degrade the pectin present in solid media. The sugar assimilation profiles and growth of selected strains in mucilage broth were studied. Therefore, 18 isolates from the selected yeasts were subjected to molecular identification by the use of 18S rRNA gene sequencing. The diversity of the yeast isolates was studied, and they were identified as Wickerhamomyces anomalus, Naganishia liquefaciens, Pichia kudriavzevii, Kazachstania naganishii and Kazachstania sp. Moreover, isolates SWU3YWP1-3, SWU3YSK9 and INFCY1-4 were used as a seed culture for Arabica coffee fermentation. The cupping sensory scores of the control (without yeast inoculation) and those inoculated with three isolated yeast strains that were determined by Q-Arabica Graders were 73.75, 84.75, 80.25 and 75.00, respectively. Unique flavors and aromas were detected. This is the first report of screening microorganisms from the Arabica coffee fermentation process by the combination of various properties with success in improving the quality of coffee beverage.

Kitasatospora humi sp. nov., isolated from a tropical peat swamp forest soil, and proposal for the reclassification of Kitasatospora psammotica as a later heterotypic synonym of Kitasatospora aureofaciens.

A polyphasic approach was used to describe strain RB6PN24T, a novel actinobacterium isolated from peat swamp forest soil collected from Rayong province, Thailand. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the strain belonged to the genus Kitasatospora and showed the highest sequence similarities to Kitasatospora kifunensis IFO 15206T (98.7 %) and Kitasatospora acidiphila MMS16-CNU292T (98.5 %). Strain RB6PN24T contained major amounts of meso-diaminopimelic acid, galactose, mannose and ribose in the whole-cell hydrolysates. MK-9(H6) and MK-9(H8) were the predominant menaquinones of the micro-organism. The polar lipids consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol, phosphatidylinositol mannosides, an unidentified lipid, four unidentified aminolipids and six unidentified phospholipids. Mycolic acids were not present. The major fatty acids were iso-C15 : 0, iso-C16 : 0, anteiso-C15 : 0, iso-C17:0, anteiso-C17 : 0 and C16 : 0. The draft genome size of strain RB6PN24T was 8.09 Mbp, with 72.1 mol% G+C content and predicted to contain at least 44 biosynthetic gene clusters encoding diverse secondary metabolites. Furthermore, the strain exhibited low average nucleotide identity and digital DNA-DNA hybridization values with K. acidiphila MMS16-CNU292T (89.1 %, 42.4 %) and K. kifunensis DSM 41654T (79.5 %, 25.5 %). The results of phenotypic, chemotaxonomic, genotypic and phylogenetic analyses revealed that strain RB6PN24T represents a novel species of the genus Kitasatospora, for which the name Kitasatospora humi sp. nov. is proposed. The type strain is RB6PN24T (=TBRC 14818T=NBRC 115116T). In addition, the comparison of the whole genome sequences and phenotypic features suggested that Kitasatospora aureofaciens and Kitasatospora psammotica belong to the same species. Therefore, it is proposed that K. psammotica is reclassified as a later heterotypic synonym of K. aureofaciens.

Description of Crinitomyces reliqui gen. nov., sp. nov. and Reassignment of Trichosporiella flavificans and Candida ghanaensis to the Genus Crinitomyces.

The systematic position of 16 yeast strains isolated from Thailand, Hungary, The Netherlands, and the Republic of Poland were evaluated using morphological, physiological, and phylogenetic analyses. Based on the similarity of the D1/D2 domain of the LSU rRNA gene, the strains were assigned to two distinct species, Trichosporiella flavificans and representatives of a new yeast species. Phylogenetic analyses revealed that Candida ghanaensis CBS 8798T showed a strong relationship with the aforementioned two species. The more fascinating issue is that Candida and Trichosporiella genera have been placed in different subphyla, Saccharomycotina and Pezizomycotina, respectively. The close relationship between Trichosporiella flavificans, Candida ghanaensis and the undescribed species was unexpected and needed to be clarified. As for morphological and physiological characteristics, the three yeast species shared a hairy colony appearance and an ability to assimilate 18 carbon sources. Based on phylogenetic analyses carried out in the present study, Crinitomyces gen. nov. was proposed to accommodate the new yeast species, Crinitomyces reliqui sp. nov. (Holotype: TBRC 15054, Isotypes: DMKU-FW23-23 and PYCC 9001). In addition, the two species Trichosporiella flavificans and Candida ghanaensis were reassigned to the genus Crinitomyces as, Crinitomyces flavificans (Type: CBS 760.79) comb. nov. and Crinitomyces ghanaensis (Type: CBS 8798) comb. nov., respectively.

Pichia bovicola sp. nov., a yeast species associated with small-intestinal content of cattle.

Three yeast strains, DMKU-MP6-4T, DMKU-MP2-6 and DMKU-MP5-1, were isolated from the small-intestinal content or Pia of cattle in Thailand during the investigation of yeast diversity in this habitat. According to the D1/D2 domain of the large subunit (LSU) rRNA gene and internal transcribed spacer (ITS) region sequence analysis, these strains represent a novel yeast species in the genus Pichia. The species produced one to four ascospores per ascus with spherical to ellipsoidal shape and heterogenous in terms of size. These three strains were identical and differed from their closely related species, Pichia exigua NRRL Y-10920T by 2% (six nucleotide substitutions and five gaps) in the D1/D2 domain of the large subunit rRNA gene, while ITS region sequences differed by 3.1% (16 nucleotide substitutions and 27 gaps), 3.7% (19 nucleotide substitutions and 28 gaps) and 3.1% (16 nucleotide substitutions and 27 gaps) for DMKU-MP6-4T, DMKU-MP2-6 and DMKU-MP5-1, respectively. The name, Pichia bovicola, is proposed to accommodate these species. The holotype is DMKU-MP6-4T (TBRC 15616T=PYCC 8905T).

Diversity of fermentative yeasts with probiotic potential isolated from Thai fermented food products.

This research aimed to evaluate the diversity of yeasts recovered from fermented foods gathered from some areas of Northeastern Thailand. The fermented food items included Pla-som, Nham-pla, Kem-buknud, Isan-sausage, Pla-ra, Mhum-neu, Mhum-Khai-pla, Nham-neu, Nham-mu, Kung-joom, Som-pla-noi, and Poo-dong. Their probiotic characteristics were also investigated. A total of 103 yeast isolates of nine genera were identified using 28S rDNA sequencing. The yeast genera were Candida (20.3%), Diutina (2.9%), Filobasidium (1.0%), Kazachstania (33.0%), Pichia (3.9%), Saccharomyces (1.0%), Starmerella (28.2%), Torulaspora (2.9%), and Yarrowia (6.8%). Based on probiotic characteristic analysis of ten selected yeast strains, Kazachstania bulderi KKKS4-1 showed the strongest probiotic characteristics in terms of hemolytic activity, antimicrobial activity against pathogenic bacteria, tolerance to low pH and bile salt and hydrophobicity. Isolated yeasts with probiotic characteristics may be useful in fermented food and animal feed production to improve their nutritional values.

Streptomyces humicola sp. nov., a novel actinobacterium isolated from peat swamp forest soil in Thailand.

A polyphasic approach was used to describe strain RB6PN25T, an actinobacterium isolated from peat swamp forest soil in Rayong Province, Thailand. The strain was a Gram-stain-positive and filamentous bacterium that contained ll-diaminopimelic acid, mannose and ribose in whole-cell hydrolysates. MK-9(H8) was the major menaquinone. The major fatty acids were iso-C16 : 0, anteiso-C15 : 0 and iso-C15 : 0. The polar lipid profile consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol, two unidentified glycophospholipids, two unidentified aminolipids and an unidentified phospholipid. The 16S rRNA gene sequences analysis indicated that it was most closely related to Streptomyces rubrisoli DSM 42083T (97.6 %) and Streptomyces palmae TBRC 1999T (97.4 %). Strain RB6PN25T exhibited low average nucleotide identity and digital DNA-DNA hybridization values with S. rubrisoli DSM 42083T (78.6 %, 23.2 %) and S. palmae TBRC 1999T (76.0 %, 22.6 %). The DNA G+C content of strain RB6PN25T was 69.9%. The results of phenotypic, chemotaxonomic, genotypic and phylogenetic analyses reveal that strain RB6PN25T represents a novel species of the genus Streptomyces, for which the name Streptomyces humicola sp. nov. is proposed. The type strain is RB6PN25T (=TBRC 14819T=NBRC 115204T).

Wickerhamiella martinezcruziae f. a., sp. nov., a yeast species isolated from tropical habitats.

Four yeast isolates with an affinity to the genus Wickerhamiella were obtained from beach sand, a marine zoanthid and a tree exudate at different localities in Brazil. Two other isolates with almost identical ITS and D1/D2 sequences of the large subunit rRNA gene were isolated from the small intestine of cattle and a grease trap in Thailand. These isolates represent a novel species phylogenetically related to Wickerhamiella verensis, Wickerhamiella osmotolerans, Wickerhamiella tropicalis, Wickerhamiella sorbophila and Wickerhamiella infanticola. The novel species differs by 15-30 nucleotide differences from these species in the D1/D2 sequences. The name Wickerhamiella martinezcruziae f.a., sp. nov. is proposed. The holotype of Wickerhamiella martinezcruziae sp. nov. is CBS 16104T. The MycoBank number is MB 839328.

Yeasts Associated with the Small-Intestinal Contents and Epithelium of Pon Yang Kham (Charolais Crossbred) Fattening Beef Cattle.

Yeast diversity in the pia and small-intestinal epithelium of Pon Yang Kham fattening cattle in Thailand was studied using a culture-dependent method. A total of 701 yeasts were isolated from the pia of the duodenum, jejunum, and ileum of the small intestine, while 425 isolates were obtained from the epithelium of all three parts of the small intestine. Yeast identification was performed and ascomycetous yeasts were found at levels of 96.9% and 86.8% in the pia and small intestine, respectively, whereas basidiomycetous yeasts were found at levels of 2.3% and 12.7%. Candida parapsilosis was the species with the highest occurrence in the duodenal and jejunal pia, with an 83.3% and 77.8% frequency of occurrence (FO), respectively. Both C. parapsilosis and C. tropicalis were species with the highest occurrence in the ileum, with a 61.1% FO. Moreover, C. parapsilosis was the species with the highest occurrence in the epithelium of the duodenum, jejunum, and ileum, with FOs of 88.2%, 87.5%, and 87.2%, respectively. Principal coordinate analysis revealed no marked differences in yeast communities from either the pia or epithelium of all three parts of the small intestine. An estimation of the expected richness of the species showed that the observed species richness was lower than the predicted richness.

Large scale production of indole-3-acetic acid and evaluation of the inhibitory effect of indole-3-acetic acid on weed growth.

Indole-3-acetic acid (IAA) is the most common plant hormone of the auxin class and regulates various plant growth processes. The present study investigated IAA production by the basidiomycetous yeast Rhodosporidiobolus fluvialis DMKU-CP293 using the one-factor-at-a-time (OFAT) method and response surface methodology (RSM). IAA production was optimized in shake-flask culture using a cost-effective medium containing 4.5% crude glycerol, 2% CSL and 0.55% feed-grade L-tryptophan. The optimized medium resulted in a 3.3-fold improvement in IAA production and a 3.6-fold reduction in cost compared with those obtained with a non-optimized medium. Production was then scaled up to a 15-L bioreactor and to a pilot-scale (100-L) bioreactor based on the constant impeller tip speed (Vtip) strategy. By doing so, IAA was successfully produced at a concentration of 3569.32 mg/L at the pilot scale. To the best of our knowledge, this is the first report of pilot-scale IAA production by microorganisms. In addition, we evaluated the effect of crude IAA on weed growth. The results showed that weed (Cyperus rotundus L.) growth could be inhibited by 50 mg/L of crude IAA. IAA therefore has the potential to be developed as a herbicidal bioproduct to replace the chemical herbicides that have been banned in various countries, including Thailand.

Amycolatopsis acididurans sp. nov., isolated from peat swamp forest soil in Thailand.

A polyphasic approach was used to describe strain K13G38T, a novel actinomycete isolated from peat swamp forest soil collected from Surat Thani Province, Thailand. The 16S rRNA gene phylogenetic analysis indicated that the strain belonged to the genus Amycolatopsis and showed the highest sequence similarities to both Amycolatopsis acidiphila JCM 30562T and Amycolatopsis bartoniae DSM 45807T (96.8% sequence similarity). Furthermore, strain K13G38T, which formed extensively branched substrate and aerial mycelia, exhibited chemotaxonomical characteristics of the genus Amycolatopsis which included phospholipid pattern type II and cell-wall chemotype IV. The polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, hydroxy-phosphatidylethanolamine, phosphatidylinositol, phosphatidylglycerol, two unidentified phospholipids, and an unidentified aminolipid. MK-9(H4) was a predominant menaquinone of the organism. The major cellular fatty acids were iso-C16:0, anteiso-C17:0, and C16:0. The genomic DNA size of strain K13G38T was 8.5 Mbp with 69.5 mol% G+C content. On the basis of phenotypic characteristics, overall genomic relatedness index and phylogenetic distinctiveness, strain K13G38T represents a novel species of the genus Amycolatopsis, for which the name A. acididurans sp. nov. is proposed. The type strain is K13G38T (=TBRC 12507T = NBRC 114553T).