Methylopila helvetica sp. nov. and Methylobacterium dichloromethanicum sp. nov.--novel aerobic facultatively methylotrophic bacteria utilizing dichloromethane

Eight strains of Gram-negative, aerobic, asporogenous, neutrophilic, mesophilic, facultatively methylotrophic bacteria are taxonomically described. These icl- serine pathway methylobacteria utilize dichloromethane, methanol and methylamine as well as a variety of polycarbon compounds as the carbon and energy source. The major cellular fatty acids of the non-pigmented strains DM1, DM3, and DM5 to DM9 are C18:1, C16:0, C18:0, Ccy19:0 and that of the pink-pigmented strain DM4 is C18:1. The main quinone of all the strains is Q-10. The non-pigmented strains have similar phenotypic properties and a high level of DNA-DNA relatedness (81-98%) as determined by hybridization. All strains belong to the alpha-subgroup of the alpha-Proteobacteria. 16S rDNA sequence analysis led to the classification of these dichloromethane-utilizers in the genus Methylopila as a new species - Methylopila helvetica sp.nov. with the type strain DM9 (=VKM B-2189). The pink-pigmented strain DM4 belongs to the genus Methylobacterium but differs from the known members of this genus by some phenotypic properties, DNA-DNA relatedness (14-57%) and 16S rDNA sequence. Strain DM4 is named Methylobacterium dichloromethanicum sp. nov. (VKM B-2191 = DSMZ 6343).     

Description of Ectothiorhodospira salini sp. nov

Strain JA430(T) is a Gram-negative, vibrioid to spiral shaped phototrophic purple sulfur bacterium isolated from anoxic sediment of a saltern at Kanyakumari in a mineral salts medium that contained 2% NaCl (w/v). Strain JA430(T) grows optimally at 5-6% NaCl and tolerates up to 12% NaCl. Intracellular photosynthetic membranes were of the lamellar type. Bacteriochlorophyll a and carotenoids of the spirilloxanthin series are present as photosynthetic pigments. Major cellular fatty acids are C(18:1)ω7c, C(16:0), C(19:0)cycloω8c and C(16:1)ω7c/C(16:1)ω6c. Strain JA430(T) exhibits photoorganoheterotrophy and chemoorganoheterotrophy and requires para-aminobenzoic acid, pantothenate and pyridoxal phosphate for growth. Phylogenetic analysis on the basis of 16S rRNA gene sequence analysis showed that strain JA430(T) forms monophyletic group in the genus Ectothiorhodospira. The highest sequence similarity for strain JA430(T) was found with the type strains of Ectothiorhodospira variabilis DSM 21381(T) (96.1%) and Ectothiorhodospira haloalkaliphila ATCC 51935(T) (96.2%). Morphological and physiological characteristics discriminate strain JA430(T) from other species of the genus Ectothiorhodospira, for which we describe this as a novel species, Ectothiorhodospira salini sp. nov. ( = NBRC 105915(T) = KCTC 5805(T)).     

Heliobacterium sulfidophilum sp. nov. andHeliobacterium undosum sp. nov.: Sulfideoxidizing heliobacteria from thermal sulfidic springs

Two new species of heliobacteria isolated from cyanobacterial mats of two alkaline sulfidic hot springs are formally described. Strains BR4 and BG29 are assigned to anoxygenic phototrophic bacteria of the familyHeliobacteriaceae, since they possess the unique properties of this taxon: strict anaerobiosis, formation of bacteriochlorophyllg, the lack of extensive intracytoplasmic membranes and chlorosomes, an unusual cell wall structure, and phylogenetic relatedness to the low G+C gram-positive eubacteria. Based on the 16S rDNA sequence similarity, strains BR4 and BG29 are assigned to the genusHeliobacterium and described as two new species of this genus:Heliobacterium sulfidophilum sp. nov. andHeliobacterium undosum sp. nov. The G+C content of the DNA is 51.3 mol % inHbt. sulfidophilum and 57.2-57.7 mol % inHbt. undosum. The cells ofHbt. sulfidophilum are rods, and the cells ofHbt. undosum are slightly twisted spirilla or short rods. Both new bacteria are motile by peritrichous flagella.Hbt. sulfidophilum produces endospores. The new bacteria are strict anaerobes growing photoheterotrophically on a limited range of organic compounds. In the dark, they can switch from photosynthesis to the slow fermentation of pyruvate. Biotin is required as a growth factor. Both species are highly tolerant to sulfide (up to 2 mM at pH 7.5) and oxidize it photoheterotrophically to elemental sulfur; photoautotrophic growth was not observed. The temperature optimal for growth ofHbt. sulfidophilum andHbt undosum is 30–35‡C, and the optimal pH is 7–8.     

Thiobacillus sajanensis sp. nov., a new obligately autotrophic sulfur-oxidizing bacterium isolated from Khoito-Gol hydrogen-sulfide springs, Buryatia

Four strains of rod-shaped gram-negative sulfur-oxidizing bacteria were isolated from Khoito-Gol hydrogen-sulfide springs in the eastern Sayan Mountains (Buryatia). The cells of the new isolates were motile by means of a single polar flagellum. The strains were obligately chemolithoautotrophic aerobes that oxidized thiosulfate (with the production of sulfur and sulfates) and hydrogen sulfide. They grew in a pH range of 6.8-9.5, with an optimum at pH 9.3 and in a temperature range of 5-39 degrees C, with an optimum at 28-32 degrees C. The cells contained ubiquinone Q-8. The DNA G+C content of the new strains was 62.3-64.2 mol %. According to the results of analysis of their 16S rRNA genes, the isolates belong to the genus Thiobacillus within the subclass Betaproteobacteria. However, the similarity level of nucleotide sequences of the 16S rRNA genes was insufficient to assign the isolates to known species of this genus. The affiliation to the genus Thiobacillus was confirmed by DNA-DNA hybridization of the isolates with the type strain of the type species of the genus Thiobacillus, T. thioparus DSM 505T (= ATCC 8158T). Despite the phenotypic similarity, the hybridization level was as low as 21-29%. In addition, considerable differences were revealed in the structure of the genes encoding RuBPC, the key enzyme of autotrophic CO2 assimilation, between the known Thiobacillus species and the new isolates. Based on molecular-biological features and certain phenotypic distinctions, the new isolates were assigned to a new Thiobacillus species, T. sajanensis sp. nov., with the type strain 4HGT (= VKM B-2365T).     

Exiguobacterium mexicanum sp. nov. and Exiguobacterium artemiae sp. nov., isolated from the brine shrimp Artemia franciscana

Two Gram-positive strains isolated from cysts of the brine shrimp Artemia franciscana were subjected to a polyphasic taxonomic analysis. Based on 16S rRNA gene sequence comparison and composition of isoprenoid quinones, peptidoglycan and fatty acids, these organisms are members of the genus Exiguobacterium. Both strains showed 95.9% 16S rRNA gene sequence similarity to one another. The 16S rRNA gene sequences of strain 8N(T) and 9AN(T) were 97.5% and 98.9% similar to those of Exiguobacterium aurantiacum DSM 6208(T) and Exiguobacterium undae DSM 14481(T), respectively. Based on differences in chemotaxonomic and physiological characteristics, results of DNA-DNA hybridization and automated riboprinting, two novel species of the genus Exiguobacterium are proposed, Exiguobacterium mexicanum sp. nov. (type strain 8N(T)=DSM 16483(T)=CIP 108859(T)) and Exiguobacterium artemiae sp. nov. (type strain 9AN(T)=DSM 16484(T)=CIP 108858(T)).     

Eight new species of the genus Micromonospora, Micromonospora citrea sp. nov., Micromonospora echinaurantiaca sp. nov., Micromonospora echinofusca sp. nov. Micromonospora fulviviridis sp. nov., Micromonospora inyonensis sp. nov., Micromonospora peucetia sp. nov., Micromonospora sagamiensis sp. nov., and Micromonospora viridifaciens sp. nov

A previous phylogenetic study on type strains of the genus Micromonospora and Micromonospora species bearing non-validly published names has pointed towards the species status of several of latter strains. Subsequent studies on morphological, cultural, chemotaxonomic, metabolic, and genomic properties, and on whole cell mass spectrometric analyses by matrix adsorbed laser desorption/ionization time-of-flight (MALDI-TOF) confirmed the species status, leading to the proposal of eight new Micromonospora species: Micromonospora citrea sp. nov., type strain DSM 43903T, Micromonospora echinaurantiaca sp. nov., type strain DSM 43904T, Micromonospora echinofusca sp. nov., type strain DSM 43913T, Micromonospora fulviviridis sp. nov., type strain DSM 43906T, Micromonospora inyonensis sp. nov., type strain DSM 46123T, Micromonospora peucetia sp. nov., type strain DSM 43363T, Micromonospora sagamiensis sp. nov., type strain DSM 43912T and Micromonospora viridifaciens sp. nov., type strain DSM 43909T.     

Description of Desulfotomaculum nigrificans subsp. salinus as a new species, Desulfotomaculum salinum sp. nov

This study focused on the physiological, chemotaxonomic, and genotypic characteristics of two thermophilic spore-forming sulfate-reducing bacterial strains, 435T and 781, of which the former has previously been assigned to the subspecies Desulfotomaculum nigrificans subsp. salinus. Both strains reduced sulfate with the resulting production of H2S on media supplemented with H2 + CO2, formate, lactate, pyruvate, malate, fumarate, succinate, methanol, ethanol, propanol, butanol, butyrate, valerate, or palmitate. Lactate oxidation resulted in acetate accumulation; butyrate was oxidized completely, with acetate as an intermediate product. Growth on acetate was slow and weak. Sulfate, sulfite, thiosulfate, and elemental sulfur, but not nitrate, served as electron acceptors for growth with lactate. The bacteria performed dismutation of thiosulfate to sulfate and hydrogen sulfide. In the absence of sulfate, pyruvate but not lactate was fermented. Cytochromes of b and c types were present. The temperature and pH optima for both strains were 60-65 degrees C and pH 7.0. Bacteria grew at 0 to 4.5-6.0% NaCl in the medium, with the optimum being at 0.5-1.0%. Phylogenetic analysis based on a comparison of incomplete 16S rRNA sequences revealed that both strains belonged to the C cluster of the genus Desulfotomaculum, exhibiting 95.5-98.3% homology with the previously described species. The level of DNA-DNA hybridization of strains 435T and 781 with each other was 97%, while that with closely related species D. kuznetsovii 17T was 51-52%. Based on the phenotypic and genotypic properties of strains 435T and 781, it is suggested that they be assigned to a new species: Desulfotomaculum salinum sp. nov., comb. nov. (type strain 435T = VKM B 1492T).     

Asterotremella meifongana sp. nov. and Asterotremella nantouana sp. nov., two anamorphic basidiomycetous yeasts isolated from soil and mushrooms

Two novel yeast species, Asterotremella meifongana sp. nov. and Asterotremella nantouana sp. nov., belonging to Asterotremellaceae within the Trichosporonales, are proposed to accommodate five strains isolated from Taiwanese samples of soil and basidiocarps during 2006-2007. Sequence analysis of the D1/D2 domains of the large subunit rRNA gene revealed that the two species are phylogenetically closely related to species of the genus Asterotremella, which indicates that they are members of the genus. The two species can be further differentiated from other Asterotremella species based on their internal transcribed spacer sequences, as well as on a few physiological test responses. The type strains are A. meifongana SN4S04(T) (=CBS 11424(T) = BCRC 23196(T)) and A. nantouana SN5S06(T) (=CBS 10890(T) = BCRC 23135(T)).     

Haliangium ochraceum gen. nov., sp. nov. and Haliangium tepidum sp. nov.: novel moderately halophilic myxobacteria isolated from coastal saline environments

Phenotypic and phylogenetic studies were performed on two myxobacterial strains, SMP-2 and SMP-10, isolated from coastal regions. The two strains are morphologically similar, in that both produce yellow fruiting bodies, comprising several sessile sporangioles in dense packs. They are differentiated from known terrestrial myxobacteria on the basis of salt requirements (2-3% NaCl) and the presence of anteiso-branched fatty acids. Comparative 16S rRNA gene sequencing studies revealed that SMP-2 and SMP-10 are genetically related, and constitute a new cluster within the myxobacteria group, together with the Polyangium vitellinum Pl vt1 strain as the closest neighbor. The sequence similarity between the two strains is 95.6%. Based on phenotypic and phylogenetic evidence, it is proposed that these two strains be assigned to a new genus, Haliangium gen. nov., with SMP-2 designated as Haliangium ochraceum sp. nov. (= JCM 11303(T) = DSM 14365(T)), and SMP-10 as Haliangium tepidum sp. nov. (= JCM 11304(T)= DSM 14436(T)).     

Heliobacterium sulfidophilum sp. Nov. and Heliobacterium undosum sp. Nov.: sulfide-oxidizing Heliobacteria from thermal sulfidic springs

Two new species of heliobacteria isolated from cyanobacterial mats of two alkaline sulfidic hot springs are formally described. Strains BR4 and BG29 are assigned to anoxygenic phototrophic bacteria of the family Heliobacteriaceae, since they possess the unique properties of this taxon: strict anaerobiosis, formation of bacteriochlorophyll g, the lack of extensive intracytoplasmic membranes and chlorosomes, an unusual cell wall structure, and phylogenetic relatedness to the low G + C gram-positive eubacteria. Based on the 16S rDNA sequence similarity, strains BR4 and BG29 are assigned to the genus Heliobacterium and described as two new species of this genus: Heliobacterium sulfidophilum sp. nov. and Heliobacterium undosum sp. nov. The G + C content of the DNA is 51.3 mol % in Hbt. sulfidophilum and 57.2-57.7 mol % in Hbt. undosum. The cells of Hbt. sulfidophilum are rods, and the cells of Hbt. undosum are slightly twisted spirilla or short rods. Both new bacteria are motile by peritrichous flagella. Hbt. sulfidophilum produces endospores. The new bacteria are strict anaerobes growing photoheterotrophically on a limited range of organic compounds. In the dark, they can switch from photosynthesis to the slow fermentation of pyruvate. Biotin is required as a growth factor. Both species are highly tolerant to sulfide (up to 2 mM at pH 7.5) and oxidize it photoheterotrophically to elemental sulfur; photoautotrophic growth was not observed. The temperature optimal for growth of Hbt. sulfidophilum and Hbt. undosum is 30-35 degrees C, and the optimal pH is 7-8.     

Hansschlegelia plantiphila gen. nov. sp. nov., a new aerobic restricted facultative methylotrophic bacterium associated with plants

A new genus, Hansschlegelia, and a new species, Hansschlegelia plantiphila, are proposed for three strains of methanol-utilizing bacteria isolated from lilac buds (strain S(1)(T)), linden buds (strain S(2)) and blue spruce needles (strain S(4)), which were selected in winter at -17 degrees C. These bacteria are aerobic, Gram-negative, colorless, non-motile short rods that multiply by binary fission and employ the ribulose bisphosphate (RuBP) and the serine pathways for C(1) assimilation. The strains have a limited number of growth substrates and use methanol, methylamine, formate, CO(2)/H(2) and glycerol as carbon and energy sources. Only strain S(1)(T) grows with ethanol and inulin. The strains are neutrophilic and mesophilic, and synthesize phytohormones (auxins and cytokinins) and vitamin B(12). Their major cellular fatty acids are saturated C(16:0), straight-chain, unsaturated C(18:1)(omega)(7) and cyclopropane C(19 cyc) acids. The main ubiquinone is ubiquinone-10 (Q-10). The dominant phospholipids are phosphatidylethanolamine, phosphatidylcholine and diphosphatidylglycerol (cardiolipin). The DNA G+C content is 68.5+/-0.2 mol%. The strains share almost identical 16S rRNA gene sequences, a high DNA-DNA hybridization value (72-86%) and represent a novel lineage of autotrophic methanol-utilizing bacteria within the Alphaproteobacteria. Collectively, these strains comprise a new genus and species H. plantiphila gen. nov., sp. nov., with strain S(1)(T) (VKM B-2347(T), NCIMB 14035(T)) as the type strain.     

Two new species of the genus Micromonospora: Micromonospora chokoriensis sp. nov. and Micromonospora coxensis sp. nov., isolated from sandy soil

Two actinomycete strains, 2-19(6)(T) and 2-30-b(28)(T), which produced single, non-motile noduler to warty spore surfaces, were isolated from sandy soil in Chokoria, Cox's Bazar, Bangladesh. A polyphasic study was carried out to establish the taxonomic position of these strains. Morphological and chemotaxonomic characteristics of these strains coincided with those of the genus Micromonospora. Phylogenetic analysis using 16S rDNA sequences indicated that these strains should be classified in the genus Micromonospora. The 16S rDNA sequence of strain 2-19(6)(T )showed closest similarity to the type strains of M. mirobrigensis (98.9%) and M. carbonacea (98.8%), and the strain 2-30-b(28)(T) to the type strains of M. purpureochromogenes (99.4%), M. halophytica (99.3%) and M. aurantiaca (99.2%). Furthermore, a combination of DNA-DNA hybridization results and some differential physiological and biochemical properties indicated that these strains were distinguished from the phylogenetically closest relatives. These strains therefore represent two novel species, for which the name Micromonospora chokoriensis sp. nov. and Micromonospora coxensis sp. nov. are proposed. The type strains are 2-19(6)(T) (=JCM 13247(T) =MTCC 8535(T)) and 2-30-b(28)(T) (=JCM 13248(T)=MTCC 8093(T)).     

Disproportionation of inorganic sulfur compounds by the sulfate-reducing bacterium Desulfocapsa thiozymogenes gen. nov., sp. nov.

A new strictly anaerobic, gram-negative bacterium was isolated from the sediment of a freshwater lake after enrichment with thiosulfate as the energy source. The strain, named Bra2 (DSM 7269), is able to grow by disproportionation of thiosulfate or sulfite to sulfate plus sulfide. Elemental sulfur is also disproportionated to sulfate and sulfide, but this only supports growth if free sulfide is chemically removed from the culture, e.g., by precipitation with amorphous ferric hydroxide. Growth is also possible by coupling the reduction of sulfate to sulfide with the oxidation of ethanol, propanol, or butanol to the corresponding fatty acid. The cells are rod-shaped, motile, and have genomic DNA with a mol% G+C content of 50.7. Cytochromes are present, but desulfoviridin is not. The new strain was shown to be related to, but distinct from members of the genus Desulfobulbus on the basis of physiological characteristics and by comparative sequence analysis of its 16S rDNA. Strain Bra2 is described as the type strain of a new taxon, Desulfocapsa thiozymogenes gen. nov., sp. nov. Received: 29 January 1996 / Accepted: 31 May 1996     

Candida alocasiicola sp. nov., Candida hainanensis sp. nov., Candida heveicola sp. nov. and Candida musiphila sp. nov., novel anamorphic, ascomycetous yeast species isolated from plants

In a taxonomic study on the ascomycetous yeasts isolated from plant materials collected in tropical forests in Yunnan and Hainan Provinces, southern China, four strains isolated from tree sap (YJ2E(T)) and flowers (YF9E(T), YWZH3C(T) and YYF2A(T)) were revealed to represent four undescribed yeast species. Molecular phylogenetic analysis based on the large subunit (26S) rRNA gene D1/D2 domain sequences showed that strain YJ2E(T) was located in a clade together with Candida haemulonii and C. pseudohaemulonii. Strain YF9E(T) was most closely related to C. azyma and strain YWZH3C(T) to C. sorbophila and C. spandovensis. Strain YYF2A(T) was clustered in a clade containing small-spored Metschnikowia species and related anamorphic Candida species. The new strains differed from their closely related described species by more than 10% mismatches in the D1/D2 domain. No sexual states were observed for the four strains on various sporulation media. The new species are therefore assigned to the genus Candida and described as Candida alocasiicola sp. nov. (type strain, YF9E(T) = AS 2.3484(T) = CBS 10702(T)), Candida hainanensis sp. nov. (type strain, YYF2A(T) = AS 2.3478(T) = CBS 10696(T)), Candida heveicola sp. nov. (type strain, YJ2E(T) = AS 2.3483(T) = CBS 10701(T)) and Candida musiphila sp. nov. (type strain, YWZH3C(T) = AS 2.3479(T) = CBS 10697(T)).     

Three new thermotolerant methylotrophic yeasts, Candida krabiensis sp. nov., Candida sithepensis sp. nov., and Pichia siamensis sp. nov., isolated in Thailand

Five strains of thermotolerant methylotrophic yeasts isolated in Thailand were found to represent three new species in the genera Pichia and Candida, based on phylogenetic analysis of D1/D2 domain of 26S rDNA, in addition to the morphological, physiological, biochemical and chemotaxonomic characterization. Three strains, FS96 and FS101 from flowers and M02 from tree flux, were characterized by ubiquinone Q7, multilateral budding, and the formation of hat-shaped ascospores that are liberated at maturation. These strains showed identical nucleotide sequences in the D1/D2 domain and formed a cluster with Candida thermophila, "Pichia salicis" and Pichia angusta. They differed by 1.9% of nucleotide substitutions from Candida thermophila, the nearest species. They were considered to represent a single new species and are described as Pichia siamensis sp. nov. Two strains, N051 and S023, isolated from soil did not produce ascospores, proliferated by multilateral budding, did not demonstrate urease or DBB color reaction, and lacked sexual stages. These characteristics correspond to the genus Candida. Strains N051 and S023 differed by 2.8% and 1.9% of nucleotide substitutions in the D1/D2 domain from the nearest species, Candida nemodendra and Candida ovalis, respectively, and are considered to represent respective new species. N051 and S023 are described as Candida krabiensis sp. nov. and Candida sithepensis sp. nov., respectively.     

Bifidobacterium reuteri sp. nov., Bifidobacterium callitrichos sp. nov., Bifidobacterium saguini sp. nov., Bifidobacterium stellenboschense sp. nov. and Bifidobacterium biavatii sp. nov. isolated from faeces of common marmoset (Callithrix jacchus) and red-handed tamarin (Saguinus midas)

Five strains of bifidobacteria were isolated from faeces of a common marmoset (Callithrix jacchus) and a red-handed tamarin (Saguinus midas). The five isolates clustered inside the phylogenetic group of the genus Bifidobacterium but did not show high sequence similarities between the isolates and to known species in the genus by phylogenetic analysis based on 16S rRNA gene sequences. Sequence analyses of dnaJ1 and hsp60 also indicated their independent phylogenetic positions to each other in the Bifidobacterium cluster. DNA G+C contents of the species ranged from 57.3 to 66.3 mol%, which is within the values recorded for Bifidobacterium species. All isolates showed fructose-6-phosphate phosphoketolase activity. Based on the data provided, the five isolates represent five novel species, for which the names Bifidobacterium reuteri sp. nov. (type strain: AFB22-1(T) = JCM 17295(T) = DSM 23975(T)), Bifidobacterium callitrichos sp. nov. (type strain: AFB22-5(T) = JCM 17296(T) = DSM 23973(T)), Bifidobacterium saguini sp. nov. (type strain: AFB23-1(T) = JCM 17297(T) = DSM 23967(T)), Bifidobacterium stellenboschense sp. nov. (type strain: AFB23-3(T) = JCM 17298(T) = DSM 23968(T)) and Bifidobacterium biavatii sp. nov. (type strain: AFB23-4(T) = JCM 17299(T) = DSM 23969(T)) are proposed.     

Rhodovulum phaeolacus sp. nov. a phototrophic alphaproteobacterium isolated from a brown pond

Two strains of oval-rod shaped, Gram-negative, phototrophic, purple non-sulfur bacteria designated JA580(T) and JA595 were isolated from a sediment sample collected from a brown pond. Strain JA580(T) was designated as the type strain, while strain JA595 as an additional strain has similar characteristics to the type strain. Strain JA580(T) was non-motile and grew photoheterotrophically with a number of organic compounds serving as carbon source/electron donor. Intracellular photosynthetic membranes were of the vesicular type. Bacteriochlorophyll a and carotenoids of the spheroidene series were present as the major photosynthetic pigments. Strain JA580(T) requires yeast extract for growth. Strain JA580(T) has an obligate requirement for sulfide or thiosulfate for growth. C(18:1)ω7c, C(18:0), C(18:1)ω9c were the predominant components of cellular fatty acids. Phylogenetic analysis on the basis of 16S rRNA gene sequences showed that strain JA580(T) clustered with species of the genus Rhodovulum of the family Rhodobacteraceae and is most closely related to the type strains of Rhodovulum adriaticum, Rhodovulum iodosum (96.5%), Rhodovulum robiginosum (96%), Rhodovulum imhoffii (95.6%) and other members of the genus Rhodovulum (<95%). On the basis of phenotypic and molecular genetic evidence, it is proposed that strain JA580(T) should be classified as a novel species of the genus Rhodovulum of the family Rhodobacteraceae, with the species name Rhodovulum phaeolacus sp. nov. The type strain of the species is JA580(T) (=NBRC 107612(T) =KCTC 5963(T)).     

Candida easanensis sp. nov., Candida pattaniensis sp. nov. and Candida nakhonratchasimensis sp. nov., three new species of yeasts isolated from insect frass in Thailand

Six strains of anamorphic yeasts isolated from insect frass collected in several regions of Thailand were assigned to the genus Candida based on the conventional taxonomic criteria used for yeast classification. These strains have Q-7 as the major ubiquinone and are suggested to have close relationships to the genus Pichia. Three strains, ST-225, ST-228 and ST-229, have identical nucleotide sequences in the D1/D2 domain of 26S rDNA and are closely related to Pichia japonica, but differ by six nucleotides (1.1% ) from this species. These three strains are considered to represent a single new species, which is described as Candida easanensis sp. nov. Two strains, ST-311 and ST-320, have identical sequences in the D1/D2 domain and resemble Pichia veronae and Pichia fabianii but differ from them by nine nucleotides (1.6%) in D1/D2 sequences. The two strains are described as Candida pattaniensis sp. nov. The remaining strain, ST-37, is related to Pichia americana and Pichia bimundalis but differs by six(1.1%) and seven (1.2%) nucleotides from these species, respectively. This strain is described as Candida nakhonratchasimensis sp. nov.