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.

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.

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.

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).

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).

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.

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.

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.

Amycolatopsis acidicola sp. nov., isolated from peat swamp forest soil.

A novel actinobacterial strain, designated K81G1T, was isolated from a soil sample collected in Kantulee peat swamp forest, Surat Thani Province, Thailand, and its taxonomic position was determined using a polyphasic approach. Optimal growth of strain K81G1T occurred at 28-30 °C, at pH 5.0-6.0 and without NaCl. Strain K81G1T had cell-wall chemotype IV (meso-diaminopimelic acid as the diagnostic diamino acid, and arabinose and galactose as diagnostic sugars) and phospholipid pattern type II, characteristic of the genus Amycolatopsis. It contained MK-9(H4) as the predominant menaquinone, iso-C16 : 0, C17 : 0 cyclo and C16 : 0 as the major cellular fatty acids, and phospholipids consisting of phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, hydroxyphosphatidylethanolamine, phosphatidylinositol and two unidentified phospholipids. Based on 16S rRNA gene sequence similarity and phylogenetic analyses, strain K81G1T was most closely related to Amycolatopsis rhizosphaerae TBRC 6029T (97.8 % similarity), Amycolatopsis acidiphila JCM 30562T (97.8 %) and Amycolatopsis bartoniae DSM 45807T (97.6 %). Strain K81G1T exhibited low average nucleotide identity and digital DNA-DNA hybridization values with A. rhizosphaerae TBRC 6029T (76.4 %, 23.0 %), A. acidiphila JCM 30562T (77.9 %, 24.6 %) and A. bartoniae DSM 45807T (77.8 %, 24.3 %). The DNA G+C content of strain K81G1T was 69.7 mol%. Based on data from this polyphasic study, strain K81G1T represents a novel species of the genus Amycolatopsis, for which the name Amycolatopsis acidicola sp. nov. is proposed. The type strain is K81G1T (=TBRC 10047T=NBRC 113896T).

Limtongozyma siamensis gen. nov., sp. nov., a yeast species in the Saccharomycetales and reassignment of Candida cylindracea to the genus Limtongozyma.

Two yeast strains, DMKU-WBL1-3 and DMKU GT3-16, were obtained from grease samples collected from grease traps at the Kasetsart University canteen, Thailand. Pairwise sequence analysis indicated that the strains were closely related to Candida cylindracea NRRL Y-17506T, but differed by 11 and 35 nucleotide substitutions in the D1/D2 domain of the large subunit (LSU) rRNA gene and the ITS region, respectively. Based on sequence divergences, the novel species was distinguished from C. cylindracea. The results of phylogenetic analysis based on the concatenated sequences from small subunit rRNA, ITS region and LSU rRNA genes showed that the two strains and C. cylindracea NRRL Y-17506T formed a distinct lineage related to the genus Babjeviella. A novel genus, Limtongozyma, is proposed to accommodate these clade members. Hence, Candida cylindracea NRRL Y-17506T is transferred to this genus and assigned as the type species of the genus. The holotype of Limtongozyma siamensis is DMKU-WBL1-3.

Savitreea pentosicarens gen. nov., sp. nov., a yeast species in the family Saccharomycetaceae isolated from a grease trap.

Two strains (DMKU-GTCP10-8 and CLIB 1740) representing a novel anamorphic yeast species were isolated from a grease sample collected from a grease trap in Thailand and from an unidentified fungus collected in French Guiana, respectively. On the basis of phylogenetic analysis based on the combined D1/D2 domain of the large subunit (LSU) rRNA gene and the internal transcribed spacer (ITS) region, Lachancea fermentati CBS 707T was the closely related species with 12.8 % sequence divergence (70 nucleotide substitutions and three gaps in 571 nucleotides) and 28.1 % sequence divergence (93 nucleotide substitutions and 90 gaps in 651 nucleotides) in the D1/D2 domain of the LSU rRNA gene and the ITS region, respectively. Phylogenetic analysis based on the concatenated sequences of the five genes including the small subunit rRNA gene, the D1/D2 domain of the LSU rRNA gene, the ITS region, translation elongation factor-1 alpha (TEF1) and RNA polymerase II subunit 2 (RPB2) genes confirmed that the two strains (DMKU-GTCP10-8 and CLIB 1740) were well-separated from other described yeast genera in Saccharomycetaceae. Hence, Savitreea pentosicarens gen. nov., sp. nov. is proposed to accommodate these two strains as members of the family Saccharomycetaceae. The holotype is S. pentosicarens DMKU-GTCP10-8T (ex-type strain TBRC 12159=PYCC 8490; MycoBank number 835044).

Wickerhamiella osmotolerans sp. nov. and Wickerhamiella tropicalis sp. nov., novel ascomycetous yeast in the family Wickerhamiellaceae.

Seven yeast strains, DMKU VGT1-14T, DMKU VGT1-19T, DMKU-JMGT1-28, DMKU-JMGT1-32, DMKU VGT2-06, DMKU VGT2-19 and DMKU VGT6-14, were isolated from a grease trap in Thailand and two strains, SJ-1 and SN-102 were isolated from the sea surface microlayer in Taiwan. On the basis of phenotypic characteristics and sequence analysis of the D1/D2 region of the large subunit (LSU) rRNA gene and the internal transcribed spacer (ITS) region, these strains represented two novel yeast species of the genus Wickerhamiella. In terms of pairwise sequence similarity, four strains, DMKU VGT1-14, DMKU-JMGT1-32, DMKU VGT6-14 and SN-102, were closely related to Wickerhamiella infanticola NRRL Y-17858T but differed by 13 nucleotide substitutions with one gap (2.46 %) in the D1/D2 domain of the LSU rRNA gene and 15 nucleotide substitutions with 23 gaps (4.2 %) in the ITS region. The strains DMKU VGT1-19T, DMKU-JMGT1-28, DMKU VGT2-06, DMKU VGT2-19 and SJ-1, differed from the type strain of the most closely related species, Wickerhamiella sorbophila NRRL Y-7921T, by nine nucleotide substitutions with one gap (1.66 %) in the D1/D2 domain of the LSU rRNA gene and nine nucleotide substitutions with 17 gaps (2.52%) in the ITS region. Hence, the names Wickerhamiella osmotolerans sp. nov. and Wickerhamiella tropicalis sp. nov. are proposed to accommodate these species in the genus Wickerhamiella. The holotypes are W. osmotolerans DMKU VGT1-14T (ex-type strain TBRC 11425=PYCC 8359=CGMCC 2.6179; Mycobank number 833394) and W. tropicalis DMKU VGT1-19T (ex-type strain TBRC 11426=PYCC 8360=CGMCC 2.6180; Mycobank number 833393).

Pseudomonas mangiferae sp. nov., isolated from bark of mango tree in Thailand.

An aerobic, Gram-stain-negative, rod-shaped bacterium, designated DMKU BBB3-04T, was isolated from bark of mango tree . Colonies were circular, convex with entire margins when grown on nutrient agar medium for 2 days. The bacterium was motile by means of lophotrichous flagella and produced black-brown pigment. The strain grew at 12-40 °C (optimum, 28-30 °C) and at pH 6.0-8.0 (pH 6.5). Growth was observed in the presence of up to 5 % (w/v) NaCl. Strain DMKU BBB3-04T showed the highest 16S rRNA gene sequence similarity to Pseudomonas furukawaii KF707T (97.1 %), Pseudomonas indica NBRC 103045T (97.0 %), Pseudomonas tarimensis MA-69T (96.9 %) and Pseudomonas azotifigens 6H33bT (96.8 %), suggesting that strain DMKU BBB3-04T should be classified within the genus Pseudomonas. Analysis of strain DMKU BBB3-04T was also performed using three housekeeping genes (gyrB,rpoB and rpoD) and further confirmed the phylogenetic assignment of the strain. The major fatty acids found in strain DMKU BBB3-04T were summed feature 8 (C18 : 1 ω7c/C18 : 1 ω6c), C16 : 0 and summed feature 3 (C16 : 1 ω7c/C16 : 1 ω6c) (35, 22 and 19 %, respectively). The major polar lipids consisted of diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylglycerol. The respiratory quinone was Q-9. The DNA G+C content of the strain DMKU BBB3-04T was 67.6 mol%. On the basis of phenotypic characteristics, chemotaxonomic data and phylogenetic analysis, strain DMKU BBB3-04T is considered to represent a novel species in the genus Pseudomonas. We propose the name Pseudomonasmangiferae sp. nov. for this novel species. The type strain of the novel species is DMKU BBB3-04T (=TBRC 7080T=JCM 32061T).

Saccharopolyspora maritima sp. nov., an actinomycete isolated from mangrove sediment.

A novel Saccharopolyspora strain, designated 3SS5-12T, isolated from mangrove sediment collected from Ranong Province is described. The strain was characterized by pale yellow branching aerial mycelium which differentiated into flexuous chains of spores covered with tufts of short curved hairs. The whole-cell hydrolysates of the strain contained meso-diaminopimelic acid as the diagnostic diamino acid, with arabinose, galactose and ribose as the main sugars. A major menaquinone of this strain was MK-9(H4). Mycolic acids were absent. The DNA G+C content of the genomic DNA was 69.4 mol%. The predominant cellular fatty acids were iso-C16 : 0 and anteiso-C17 : 0. Polar lipids consisted of diphosphatidylglycerol, hydroxy-phosphatidylethanolamine, hydroxy-phosphatidylmonomethylethanolamine, phosphatidylethanolamine, phosphatidylmonomethylethanolamine, phosphatidylcholine, phosphatidylglycerol, phosphatidylinositol, unidentified phospholipids and unidentified lipids. Phylogenetic determination based on 16S rRNA gene sequences indicated that the organism was classified in the genus Saccharopolyspora and highly similar to Saccharopolyspora jiangxiensis W12T (98.8 % sequence similarity), Saccharopolyspora hirsutasubsp. kobensis JCM 9109T (98.8 %), Saccharopolyspora antimicrobica I05-00074T (98.2 %) and Saccharopolyspora indica VRC122T (98.1 %). Evidence from the chemotaxonomic, phenotypic and molecular systematic data indicated that strain 3SS5-12T should be classified as a representing novel species of the genus Saccharopolyspora, for which the name Saccharopolyspora maritima sp. nov. is proposed. The type strain is 3SS5-12T (=TBRC 7048T=NBRC 112863T).

Papiliotrema phichitensis f.a., sp. nov., a novel yeast species isolated from sugarcane leaf in Thailand.

Strain DMKU-SP105T representing a novel yeast species was isolated from the external surface of a sugarcane leaf (Saccharum officinarum L.) collected from a sugarcane plantation field in Phichit province, Thailand. On the basis of sequence analysis of the D1/D2 region of the large subunit (LSU) rRNA gene and the internal transcribed spacer (ITS) region, the strain DMKU-SP105T differed by 7-16 substitutions in the D1/D2 region of LSU rRNA gene and 6-22 substitutions in the ITS region from a group of related species, Papiliotrema aspenensis, Papiliotrema odontotermitis, Papiliotrema rajasthanensis and Papiliotrema laurentii. A phylogenetic analysis based on the concatenated sequences of ITS region and the D1/D2 region of the LSU rRNA gene indicated that strain DMKU-SP105T belongs to the laurentii clade of Papiliotrema in the Tremellales and is distinct from other related species in the clade. It therefore represents a novel species of the genus Papiliotrema although the formation of basidiospores was not observed. The name Papiliotrema phichitensis f.a., sp. nov. is proposed. The type is DMKU-SP105T (= CBS 13390T = BCC 61187T = NBRC 109699T).

Cyberlindnera tropicalis f.a., sp. nov., a novel yeast isolated from tropical regions.

Two yeast strains, DMKU-WBBC14 and UFMG-CM-Y3283, were isolated from soil in Samutprakarn province in the central part of Thailand and from rotting wood in an Amazonian forest site in the Roraima State in Brazil, respectively. The two strains showed identical sequences of the D1/D2 domain of the large subunit (LSU) rRNA gene and different sequences by three nucleotide substitutions of the internal transcribed spacer (ITS) region. Therefore, these two strains represented a single species which was most closely related to Cyberlindnera mengyuniae CBS 10845T. The nucleotide sequence differences between the two strains of the novel species and the type strain Cyberlindnera mengyuniae CBS 10845T were 10 substitutions in the D1/D2 region of the LSU rRNA gene and 46 substitutions in the ITS region. DMKU-WBBC14 and UFMG-CM-Y3283 differed in growth temperature profiles. Moreover, they also exhibited different carbon assimilation profiles and growth temperature profiles from the type strain of Cyberlindnera mengyuniae, CBS 10845T. The name Cyberlindnera tropicalis f.a., sp. nov. is proposed. The type strain is DMKU-WBBC14T (=CBS 14558T=TBRC 6562T). The Mycobank number is MB 819722.

Enhanced production of raw starch degrading enzyme using agro-industrial waste mixtures by thermotolerant Rhizopus microsporus for raw cassava chip saccharification in ethanol production.

In the present study, solid-state fermentation for the production of raw starch degrading enzyme was investigated by thermotolerant Rhizopus microsporus TISTR 3531 using a combination of agro-industrial wastes as substrates. The obtained crude enzyme was applied for hydrolysis of raw cassava starch and chips at low temperature and subjected to nonsterile ethanol production using raw cassava chips. The agro-industrial waste ratio was optimized using a simplex axial mixture design. The results showed that the substrate mixture consisting of rice bran:corncob:cassava bagasse at 8 g:10 g:2 g yielded the highest enzyme production of 201.6 U/g dry solid. The optimized condition for solid-state fermentation was found as 65% initial moisture content, 35°C, initial pH of 6.0, and 5 × 106 spores/mL inoculum, which gave the highest enzyme activity of 389.5 U/g dry solid. The enzyme showed high efficiency on saccharification of raw cassava starch and chips with synergistic activities of commercial α-amylase at 50°C, which promotes low-temperature bioethanol production. A high ethanol concentration of 102.2 g/L with 78% fermentation efficiency was achieved from modified simultaneous saccharification and fermentation using cofermentation of the enzymatic hydrolysate of 300 g raw cassava chips/L with cane molasses.

Indole-3-acetic acid biosynthetic pathways in the basidiomycetous yeast Rhodosporidium paludigenum.

Microorganisms produce plant growth regulators, such as auxins, cytokinins and gibberellins, to promote plant growth. Auxins are a group of compounds with an indole ring that have a positive effect on plant growth. Indole-3-acetic acid (IAA) is a plant growth hormone classified as an indole derivative of the auxin family. IAA biosynthesis pathways have been reported and widely studied in several groups of bacteria. Only a few studies on IAA biosynthesis pathways have been conducted in yeast. This study aimed to investigate IAA biosynthesis pathways in a basidiomycetous yeast (Rhodosporidium paludigenum DMKU-RP301). Investigations were performed both with and without a tryptophan supplement. Indole compound intermediates were detected by gas chromatography-mass spectrometry. Indole-3-lactic acid and indole-3-ethanol were found as a result of the enzymatic reduction of indole-3-pyruvic acid and indole-3-acetaldehyde, in IAA biosynthesis via an indole-3-pyruvic acid pathway. In addition, we also found indole-3-pyruvic acid in culture supernatants determined by high-performance liquid chromatography. Identification of tryptophan aminotransferase activity supports indole-3-pyruvic acid-routed IAA biosynthesis in R. paludigenum DMKU-RP301. We hence concluded that R. paludigenum DMKU-RP301 produces IAA through an indole-3-pyruvic acid pathway.

Nonomuraea purpurea sp. nov., an actinomycete isolated from mangrove sediment.

A polyphasic approach was used to verify the novel actinomycete, strain 1SM4-01T, isolated from mangrove sediment collected from Ranong Province, Thailand. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the organism was a member of the genus Nonomuraea and was most closely related to Nonomuraea syzygii GKU 164T (98.7 % sequence similarity), Nonomuraea rhizophila YIM 67092T (98.4 %), Nonomuraea solani NEAU-Z6T (98.4 %), Nonomuraea monospora PT708T (98.3 %) and Nonomuraea thailandensis KC-061T (98.2 %). The strain produced branching aerial mycelium which differentiated into straight chains of rough-surfaced spores borne at the end of a short sporophore. The whole-cell hydrolysates contained meso-diaminopimelic acid as the diagnostic diamino acid, with madurose, mannose and ribose as the main sugars. MK-9(H4) was a major menaquinone of this strain. The acyl type of peptidoglycan was N-acetyl. The predominant cellular fatty acids were C17 : 1ω8c and iso-C16 : 0. Phospholipids consisted of diphosphatidylglycerol, hydroxy-phosphatidylethanolamine, hydroxy-phosphatidylmonomethylethanolamine, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol, phosphatidylinositol mannoside, aminophospholipids and unidentified lipids. The G+C content of the genomic DNA was 70.4 mol%. On the basis of phenotypic characteristics, DNA-DNA relatedness and phylogenetic distinctiveness, strain 1SM4-01T represents a novel species of the genus Nonomuraea, for which the name Nonomuraea purpurea sp. nov. is proposed. The type strain is 1SM4-01T (=BCC 60397T=NBRC 109647T).