A simple HPLC method for analysing diaminopimelic acid diastereomers in cell walls of Gram-positive bacteria

Chryseomicrobium aureum sp. nov., a bacterium isolated from activated sludge

A Gram-stain-positive, rod-shaped, non-motile, non-spore-forming, aerobic bacterial strain, designated BUT-2T, was isolated from activated sludge of one herbicide-manufacturing wastewater-treatment facility in Kunshan, Jiangsu province, China, and subjected to polyphasic taxonomic studies. Analysis of the 16S rRNA gene sequence indicated that strain BUT-2T shared the highest similarity with Chryseomicrobium amylolyticum (98.98 %), followed by Chryseomicrobium imtechense (98.88 %), with less than 96 % similarlity to members of the genera Paenisporosarcina , Planococcus , Sporosarcina and Planomicrobium . Phylogenetic analysis based on the 16S rRNA gene sequence showed that strain BUT-2T clustered with C. amylolyticum JC16T and C. imtechense MW10T, occupying a distinct phylogenetic position. The major fatty acid (>10 % of total fatty acids) type of strain BUT-2T was iso-C15 : 0. The quinone system comprised menaquinone MK-7 (77.8 %), MK-6 (11.9 %) and MK-8 (10.3 %). The polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and some unidentified phospholipids. The cell-wall peptidoglycan type of strain BUT-2T was l-Orn-d-Glu. The genomic DNA G+C content of strain BUT-2T was 48.5 mol%. Furthermore, the DNA–DNA relatedness in hybridization experiments against the reference strain was lower than 70 %, confirming that strain BUT-2T did not belong to previously described species of the genus Chryseomicrobium . On the basis of its morphological, physiological and chemotaxonomic characteristics as well as phylogenetic analysis, strain BUT-2T is considered to represent a novel species of the genus Chryseomicrobium , for which the name Chryseomicrobium aureum sp. nov. is proposed. The type strain is BUT-2T ( = CCTCC AB2013082T = KACC 17219T).

Nonomuraea fuscirosea sp. nov., an actinomycete isolated from the rhizosphere soil of rehmannia (Rehmannia glutinosa Libosch)

A novel actinomycete, designated strain NEAU-dht8T, was isolated from the rhizosphere soil of rehmannia (Rehmannia glutinosa Libosch) and characterized using a polyphasic approach. The organism was found to have morphological and chemotaxonomic characteristics typical of the genus Nonomuraea . The G+C content of the DNA was 68.47 mol%. On the basis of 16S rRNA gene sequence similarity studies, strain NEAU-dht8T was most closely related to Nonomuraea maheshkhaliensis 16-5-14T (99.31 %), Nonomuraea kuesteri GW 14-1925T (98.77 %), Nonomuraea coxensis JCM 13931T (98.71 %), Nonomuraea wenchangensis 210417T (98.44 %), Nonomuraea bangladeshensis 5-10-10T (98.36 %) and Nonomuraea salmonea DSM 43678T (98.0 %); similarities to other species of the genus Nonomuraea were lower than 98 %. Two tree-making algorithms based on 16S rRNA gene sequences showed that the isolate formed a phyletic line with its closest neighbour N. maheshkhaliensis 16-5-14T. However, the low level of DNA–DNA relatedness allowed the novel isolate to be differentiated from N. maheshkhaliensis 16-5-14T. Strain NEAU-dht8T could also be differentiated from other species of the genus Nonomuraea showing high 16S rRNA gene sequence similarity (98–98.77 %) by morphological and physiological characteristics. Thus, strain NEAU-dht8T is considered to represent a novel species of the genus Nonomuraea , for which the name Nonomuraea fuscirosea sp. nov. is proposed. The type strain is NEAU-dht8T ( = CGMCC 4.7104T = DSM 45880T).

Actinomycetospora atypica sp. nov., a novel soil actinomycete and emended description of the genus Actinomycetospora

A novel actinomycete, designated strain NEAU-st4(T), was isolated from a soil sample collected from Shaanxi province, Northwest China and characterized using a polyphasic approach. 16S rRNA gene sequence analysis revealed that strain NEAU-st4(T) has the highest sequence similarities with Actinomycetospora rishiriensis RI109-Li102(T) (99.4 %), Actinomycetospora corticicola 014-5(T) (99.1 %), Actinomycetospora chiangmaiensis YIM 0006(T) (98.8 %) and Actinomycetospora iriomotensis IR73-Li102(T) (98.2 %). However, the low level of DNA-DNA relatedness differentiated strain NEAU-st4(T) from its closest phylogenetic neighbours. The main chemotaxonomic properties of strain NEAU-st4(T), such as the diamino acid of the peptidoglycan, the whole-cell hydrolysates, the predominant menaquinones and the phospholipid profile, supported its classification within the genus Actinomycetospora. The distinctive morphology of this strain compared with that of other members in the genus Actinomycetospora is the formation of sporangia directly on the substrate hyphae. Phenotypic and genotypic differences also allowed the distinction of the strain from closely related species. Consequently, strain NEAU-st4(T) represents a new species of the genus Actinomycetospora, for which the name Actinomycetospora atypica sp. nov. is proposed. The type strain is NEAU-st4(T) (=CGMCC 4.7093(T) = DSM 45873(T)).

Actinoplanes lutulentus sp. nov., isolated from mucky soil in China

A novel actinomycete, designated strain NEAU-GRX6T, was isolated from mucky soil collected from a stream of Jinlong Mountain in Harbin, Heilongjiang Province, north China, and characterized using a polyphasic approach. The isolate formed irregular sporangia containing motile sporangiospores on the substrate mycelium. The whole-cell sugars were xylose, glucose and galactose. The predominant menaquinones were MK-9(H6), MK-10(H4) and MK-9(H4). The major fatty acids were C16:0, C15:0, C18:1ω9c, C17:1ω7c and C18:0. The phospholipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol and phosphatidylinositol. The DNA G+C content was 67 mol%. 16S rRNA gene sequence similarity studies showed that strain NEAU-GRX6T belonged to the genus Actinoplanes, being most closely related to Actinoplanes palleronii IFO 14916T (97.80% similarity) and Actinoplanes missouriensis NBRC 102363T (97.76%). However, the low observed levels of DNA-DNA relatedness allowed the isolate to be differentiated from the above-mentioned species of the genus Actinoplanes. Moreover, strain NEAU-GRX6T could also be distinguished from A. palleronii IFO 14916T and A. missouriensis NBRC 102363T by phenotypic characteristics. Therefore, it is proposed that strain NEAU-GRX6T represents a novel species of the genus Actinoplanes, for which the name Actinoplanes lutulentus sp. nov. is proposed. The type strain is strain NEAU-GRX6T (=CGMCC 4.7090T=DSM 45883T).

Micromonospora polyrhachis sp. nov., an actinomycete isolated from edible Chinese black ant (Polyrhachis vicina Roger)

A novel actinomycete, designated strain NEAU-ycm2T, was isolated from edible Chinese black ants (Polyrhachis vicina Roger) and characterized using a polyphasic approach. The organism was found to have morphological and chemotaxonomic characteristics typical of the genus Micromonospora . The 16S rRNA gene sequence of strain NEAU-ycm2T showed highest similarity to those of Micromonospora sonneratiae 274745T (99.12 %), Micromonospora pattaloongensis TJ2-2T (98.85 %), Micromonospora pisi GUI 15T (98.76 %), Polymorphospora rubra TT 97-42T (98.42 %) and Micromonospora eburnea LK2-10T (98.21 %). Phylogenetic analysis based on the 16S rRNA gene and gyrB gene demonstrated that strain NEAU-ycm2T is a member of the genus Micromonospora and supported the close phylogenetic relationship to M. sonneratiae 274745T, M. pattaloongensis JCM 12833T and M. pisi GUI 15T. Furthermore, a combination of DNA–DNA hybridization and some physiological and biochemical properties indicated that the novel strain could be readily distinguished from its closest phylogenetic relatives. Therefore, it is proposed that NEAU-ycm2T represents a novel species of the genus of Micromonospora , for which the name Micromonospora polyrhachis sp. nov. is proposed. The type strain is NEAU-ycm2T ( = CGMCC 4.7100T = DSM 45886T).

Bacillus luteus sp. nov., isolated from soil

Two bacterial strains (JC167T and JC168) were isolated from a soil sample collected from Mandpam, Tamilnadu, India. Colonies of both strains were orange and cells Gram-stain-positive. Cells were small rods, and formed terminal endospores of ellipsoidal to oval shape. Both strains were positive for catalase, oxidase and hydrolysis of starch/gelatin, and negative for chitin hydrolysis, H2S production, indole production and nitrate reduction activity. Major fatty acids of both strains (>5%) were anteiso-C15:0, iso-C16:0, iso-C15:0, anteiso-C17:0, iso-C14:0 and C16:0 with minor (<5 but >1%) amounts of iso-C17:0, anteiso-C17:0 B/iso-C17:0 I and C16:1ω11c. Diphosphatydilglycerol, phosphatidylethanolamine and phosphatidylglycerol were the major polar lipids of both strains. Cell wall amino acids were L-alanine, D-alanine, D-glutamic acid and meso-diaminopimelic acid. β-Carotene and five unidentified carotenoids were present in both strains. Mean genomic DNA G+C content was 53.4±1 mol% and the two strains were closely related (mean DNA-DNA hybridization>90%). 16S rRNA gene sequence comparisons of both strains indicated that they represent species of the genus Bacillus within the family Bacillaceae of the phylum Firmicutes. Both strains had a sequence similarity of 97.6% with Bacillus saliphilus 6AGT and <96.8% with other members of the genus Bacillus. Sequence similarity between strain JC167T and 168 was 100%. Strain JC167T showed 25.8±1% reassociation (based on DNA-DNA hybridization) with B. saliphilus DSM 15402T (=6AGT). Distinct morphological, physiological and genotypic differences from previously described taxa support the classification of strain JC167T as a representative of a novel species of the genus Bacillus, for which the name Bacillus luteus sp. nov. is proposed. The type strain is JC167T (=KCTC 33100T=LMG 27257T).

Streptomyces zhaozhouensis sp. nov., an actinomycete isolated from candelabra aloe (Aloe arborescens Mill)

A novel endophytic actinomycete, designated strain NEAU-LZS-5(T), was isolated from the leaf of candelabra aloe (Aloe arborescens Mill) and characterized using a polyphasic approach. Analysis of the 16S rRNA gene sequence showed that strain NEAU-LZS-5(T) belongs to the genus Streptomyces and exhibited 99.51 and 97.37 % similarity to Streptomyces sedi YIM 65188(T) and Streptomyces specialis GW41-1564(T), respectively, whereas low similarity values (<97 %) distinguished strain NEAU-LZS-5(T) from all other species of the genus Streptomyces with validly published names. Two tree-making algorithms also supported the position that strain NEAU-LZS-5(T) formed a distinct clade with Streptomyces sedi YIM 65188(T) and Streptomyces specialis GW41-1564(T). However, levels of DNA-DNA relatedness between strain NEAU-LZS-5(T) and Streptomyces sedi YIM 65188(T) and Streptomyces specialis GW41-1564(T) were 45.59 and 31.90 %, respectively. A comparative study between strain NEAU-LZS-5(T) and the type strains of closest related species of the genus Streptomyces revealed that it differed from them in morphological, physiological and biochemical characteristics. Therefore, strain NEAU-LZS-5(T) represents a novel species of the genus Streptomyces, for which the name Streptomyces zhaozhouensis sp. nov. is proposed. The type strain is NEAU-LZS-5(T) ( = CGMCC 4.7095(T) = DSM 42101(T)).

Nonomuraea guangzhouensis sp. nov., and Nonomuraea harbinensis sp. nov., two novel actinomycetes isolated from soil

Two novel actinomycetes, designated strains NEAU-ZJ3(T) and NEAU-yn31(T), were isolated from soils in China and their taxonomic positions determined by a polyphasic approach. Key morphological and chemotaxonomic properties of the two strains were consistent with the description of the genus Nonomuraea. The G+C contents of strains NEAU-ZJ3(T) and NEAU-yn31(T) were determined to be 67.4 and 68.0 %, respectively. Phylogenetic analysis using 16S rRNA gene sequences indicated that the two strains should be classified in the genus Nonomuraea. The 16S rRNA gene sequence of strain NEAU-ZJ3(T) showed it to be most closely related to Nonomuraea salmonea DSM 43678(T) (98.27 %), Nonomuraea endophytica YIM 65601(T) (98.23 %) and Nonomuraea candida HMC10(T) (98.08 %), and that of strain NEAU-yn31(T) to Nonomuraea ferruginea IFO 14094(T) (99.08 %) and N. candida HMC10(T) (98.01 %). Furthermore, a combination of DNA-DNA hybridization results and some phenotypic characteristics indicated that the two strains can be distinguished from each other and their phylogenetically closest relatives. Thus, strains NEAU-ZJ3(T) and NEAU-yn31(T) represent two novel species of the genus Nonomuraea, for which the names Nonomuraea guangzhouensis sp. nov. and Nonomuraea harbinensis sp. nov. are proposed. The type strains are NEAU-ZJ3(T) (=CGMCC 4.7101(T) = DSM 45889(T)) and NEAU-yn31(T) (=CGMCC 4.7106(T) = DSM 45887(T)), respectively.

Streptomyces harbinensis sp. nov., an endophytic, ikarugamycin-producing actinomycete isolated from soybean root [Glycine max (L.) Merr]

A novel ikarugamycin-producing actinomycete, designated strain NEAU-Da3(T), was isolated from soybean root [Glycine max (L.) Merr.] and characterized using a polyphasic approach. 16S rRNA gene sequence similarity studies showed that strain NEAU-Da3(T) belonged to the genus Streptomyces, and was most closely related to Streptomyces carpaticus NRRL B-16359(T) (99.5 %), Streptomyces cheonanensis VC-A46(T) (99.3 %) and Streptomyces xiamenensis MCCC 1A01550(T) (97.2 %); similarities to other type strains of species of the genus Streptomyces were lower than 97.1 %. The maximum-likelihood phylogenetic tree based on 16S rRNA gene sequences showed that the isolate formed a distinct phyletic line with S. carpaticus NRRL B-16359(T), S. cheonanensis VC-A46(T) and S. xiamenensis MCCC 1A01550(T). This branching pattern was also supported by the tree reconstructed with the neighbour-joining method. A comparative study between strain NEAU-Da3(T) and the type strains of the closest related species of the genus Streptomyces revealed that it differed from them in morphological, physiological and biochemical characteristics. Therefore, it is proposed that strain NEAU-Da3(T) represents a novel species of the genus Streptomyces, for which the name Streptomyces harbinensis sp. nov. is proposed. The type strain is NEAU-Da3(T) ( = CGMCC 4.7047(T) = DSM 42076(T)).

Streptomyces heilongjiangensis sp. nov., a novel actinomycete that produces borrelidin isolated from the root surface of soybean [Glycine max (L.) Merr]

A borrelidin-producing actinomycete, designated strain NEAU-W2(T), was isolated from the root surface of soybean [Glycine max (L.) Merr] and characterized using a polyphasic approach. The organism was found to have morphological and chemotaxonomic characteristics typical of streptomycetes. The G+C content of the DNA was 66.12 mol%. Analysis of the 16S rRNA gene sequence of strain NEAU-W2(T) revealed that the strain formed a distinct clade within the 16S rRNA gene sequence phylogenetic tree and showed highest similarity (99.61 %) to Streptomyces neyagawaensis ATCC 27449(T). However, the DNA-DNA relatedness between strain NEAU-W2(T) and S. neyagawaensis ATCC 27449(T) was 58.51 %. Strain NEAU-W2(T) could also be differentiated from S. neyagawaensis ATCC 27449(T) and other Streptomyces species showing high 16S rRNA gene sequence similarity (98-99 %), as well as other borrelidin-producing strains, based on morphological and physiological characteristics. On the basis of its physiological and molecular properties, it is proposed that strain NEAU-W2(T) represents a novel Streptomyces species, Streptomyces heilongjiangensis sp. nov. The type strain is NEAU-W2(T) ( = CGMCC 4.7004(T)  = ATCC BAA-2424(T)  = DSM 42073(T)).

Actinoplanes hulinensis sp. nov., a novel actinomycete isolated from soybean root (Glycine max (L.) Merr)

A novel actinomycete, designated strain NEAU-M9(T), was isolated from soybean root (Glycine max (L.) Merr) and characterized using a polyphasic approach. 16S rRNA gene sequence similarity studies showed that strain NEAU-M9(T) belonged to the genus Actinoplanes, being most closely related to Actinoplanes campanulatus DSM 43148(T) (98.85 %), Actinoplanes capillaceus DSM 44859(T) (98.70 %), Actinoplanes lobatus DSM 43150(T) (98.30 %), Actinoplanes auranticolor DSM 43031(T) (98.23 %) and Actinoplanes sichuanensis 03-723(T) (98.06 %); similarity to other type strains of the genus Actinoplanes ranged from 95.87 to 97.56 %. The neighbour-joining phylogenetic tree based on 16S rRNA gene sequences showed that the isolate formed a distinct phyletic line with A. campanulatus DSM 43148(T) and A. capillaceus DSM 44859(T). This branching pattern was also supported by the tree constructed with the maximum-likelihood method. However, the low level of DNA-DNA relatedness allowed the isolate to be differentiated from the above-mentioned two Actinoplanes species. Moreover, strain NEAU-M9(T) could also be distinguished from the most closely related species by morphological, physiological and characteristics. Therefore, it is proposed that strain NEAU-M9(T) represents a novel Actinoplanes species, Actinoplanes hulinensis sp. nov. The type strain of Actinoplanes hulinensis is NEAU-M9(T) (= CGMCC 4.7036(T) = DSM 45728(T)).

Wangella harbinensis gen. nov., sp. nov., a new member of the family Micromonosporaceae

A novel endophytic actinomycete, designated strain NEAU-J3(T), was isolated from soybean root (Glycine max (L.) Merr) and characterized using a polyphasic approach. Phylogenetic analysis based on 16S rRNA gene sequences suggested that strain NEAU-J3(T) fell within the family Micromonosporaceae. The strain was observed to form an extensively branched substrate mycelium, which carried non-motile oval spores with a smooth surface. The cell walls of strain NEAU-J3(T) were determined to contain meso-diaminopimelic acid and galactose, ribose and glucose were detected as whole-cell sugars. The major menaquinones were determined to be MK-9(H(4)) and MK-9(H(6)). The phospholipids detected were phosphatidylcholine and phosphatidylethanolamine. The major cellular fatty acids were determined to be C(16:0), C(18:1) ω9c, C(18:0), C(17:0), C(17:1) ω7c, anteiso-C(17:0), C(16:1) ω7c and C(15:0). The DNA G + C content was 62.5 mol%. On the basis of the morphological and chemotaxonomic characteristics, phylogenetic analysis and characteristic patterns of 16S rRNA gene signature nucleotides, strain NEAU-J3(T) is considered to represent a novel species of a new genus within the family Micromonosporaceae, for which the name Wangella harbinensis gen. nov., sp. nov. is proposed. The type strain of Wangella harbinensis is strain NEAU-J3(T) (=CGMCC 4.7039(T) = DSM 45747(T)).

Chryseomicrobium amylolyticum sp. nov., isolated from a semi-arid tropical soil, and emended descriptions of the genus Chryseomicrobium and Chryseomicrobium imtechense

A rod-shaped, non-motile, Gram-stain-positive, catalase-positive, starch-hydrolysing strain, JC16(T), was isolated from a semi-arid tropical soil from India. Phylogenetic analysis based on 16S rRNA gene sequence showed that strain JC16(T) clustered with the type species of the genus Chryseomicrobium, Chryseomicrobium imtechense MW 10(T), a member of the family Planococcaceae within the phylum Firmicutes with 99.3 % sequence similarity. Major (>10 %) fatty acids of strain JC16(T) were iso-C15 : 0 and iso-C16 : 0. Minor (<10 and >1 %) amounts of C16 : 0, iso-C14 : 0, anteiso-C15 : 0, iso-C17 : 0, anteiso-C17 : 0, iso-C17 : 1ω10c and C16 : 1ω11c are present in strain JC16(T). Polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phospholipids (PL2-4), aminolipids (AL1, 2) and an unknown lipid. Cell wall peptidoglycan was of the type l-Orn-D-Glu. The quinone system was composed of MK-7, MK-8 and MK-6. Genomic DNA G+C content of strain JC16(T) was 57.6 mol%. Distinct physiological, chemotaxonomic and genotypic differences (37 % reassociation based on DNA-DNA hybridization) from Chryseomicrobium imtechense MW 10(T) support the classification of strain JC16(T) as a representative of a novel species in the genus Chryseomicobium, for which the name Chryseomicrobium amylolyticum sp. nov. (type strain JC16(T) = DSM 23442(T) = NBRC 105215(T)) is proposed.

Nonomuraea solani sp. nov., an actinomycete isolated from eggplant root (Solanum melongena L.)

A novel actinomycete, designated strain NEAU-Z6(T), was isolated from eggplant (Solanum melongena L.) root. Phylogenetic analysis based on the 16S rRNA gene sequence showed that strain NEAU-Z6(T) belonged to the genus Nonomuraea, with highest sequence similarity to Nonomuraea monospora PT 708(T) (98.83 %), Nonomuraea rosea GW 12687(T) (98.55 %) and Nonomuraea rhizophila YIM 67092(T) (98.02 %). Sequence similarities between strain NEAU-Z6(T) and other species of the genus Nonomuraea ranged from 97.94 % (Nonomuraea candida HMC10(T)) to 96.30 % (Nonomuraea wenchangensis 210417(T)). Key morphological, physiological and chemotaxonomic characteristics of strain NEAU-Z6(T) were congruent with the description of the genus Nonomuraea. The G+C content of the genomic DNA was 64.51 mol%. DNA-DNA relatedness and comparative analysis of physiological, biochemical and chemotaxonomic data allowed genotypic and phenotypic differentiation of strain NEAU-Z6(T) from closely related species. Thus, strain NEAU-Z6(T) represents a novel species of the genus Nonomuraea, for which the name Nonomuraea solani sp. nov. is proposed. The type strain is NEAU-Z6(T) ( = CGMCC 4.7037(T) = DSM 45729(T)).

Xiangella phaseoli gen. nov., sp. nov., a member of the family Micromonosporaceae

A novel endophytic actinomycete, designated strain NEAU-J5(T) was isolated from roots of snap bean (Phaseolus vulgaris L.). Comparative analysis of the 16S rRNA gene sequence indicated that NEAU-J5(T) is phylogenetically related to members of the family Micromonosporaceae. The whole-cell sugars were galactose, mannose and glucose. The predominant menaquinones were MK-9(H4) and MK-9(H6). The major fatty acids were C16:0, C18:0, C17:1ω7c, iso-C15:0 and C17:0. The phospholipids were phosphatidylmethylethanolamine, phosphatidylethanolamine, phosphatidylcholine, phosphatidylinositol and phosphatidylinositol mannoside. The DNA G+C content was 72.2 mol%. On the basis of the morphological and chemotaxonomic characteristics, phylogenetic analysis and characteristic patterns of 16S rRNA gene signature nucleotides, strain NEAU-J5(T) represents a novel species of a new genus within the family Micromonosporaceae, for which the name Xiangella phaseoli gen. nov., sp. nov. is proposed. The type strain of Xiangella phaseoli is strain NEAU-J5(T) (=CGMCC 4.7038(T)=DSM 45730(T)).

Borrelidin, a potent antifungal agent: insight into the antifungal mechanism against Phytophthora sojae

Borrelidin has high and specific antifungal activity against Phytophthora sojae . To explore the antifungal mechanism of borrelidin against P. sojae , the relationship between the antifungal activity of borrelidin and the concentration of threonine was evaluated. The results demonstrated that the growth-inhibitory effect of borrelidin on the growth of P. sojae was antagonized by threonine in a dose-dependent manner, suggesting that threonyl-tRNA synthetase (ThrRS) may be the potential target of borrelidin. Subsequently, the inhibition of the enzymatic activity of ThrRS by borrelidin in vitro was confirmed. Furthermore, the detailed interaction between ThrRS and borrelidin was investigated using fluorescence spectroscopy and circular dichroism (CD), implying a tight binding of borrelidin to ThrRS. Taken together, these results suggest that the antifungal activity of borrelidin against P. sojae was mediated by inhibition of ThrRS via the formation of the ThrRS-borrelidin complex.

Georgenia satyanarayanai sp. nov., an alkaliphilic and thermotolerant amylase-producing actinobacterium isolated from a soda lake

A Gram-stain-positive, oxidase-negative, starch-hydrolysing, actinobacterium (strain JC82T) was isolated from a soda lake in Lonar, India. Based on 16S rRNA gene sequence similarity studies, strain JC82T belonged to the genus Georgenia and was most closely related to Georgenia muralis 1A-CT (96.8 %) and other members of the genus Georgenia (<96.5 %). The DNA G+C content of strain JC82T was 73.4 mol%. The cell-wall amino acids were alanine, glutamic acid and lysine with peptidoglycan type A4α. Polar lipids included diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, phosphatidylinositol mannosides, an unidentified lipid (L1) and an unidentified glycolipid (GL3). The predominant isoprenoid quinone was menaquinone MK-8(H4). Anteiso-C15 : 0 was the predominant fatty acid and significant proportions of iso-C14 : 0, C14 : 0, C16 : 0, iso-C15 : 0 and iso-C16 : 0 were also detected. Strain JC82T produced thermostable alkaline amylase. The results of physiological and biochemical tests allowed a clear phenotypic differentiation of strain JC82T from all other members of the genus Georgenia . Based on these data, strain JC82T represents a novel species of the genus Georgenia , for which the name Georgenia satyanarayanai sp. nov. is proposed. The type strain is JC82T ( = KCTC 19802T = NBRC 107612T).

Occurrence and degradation of peptidoglycan in aquatic environments

Mechanisms controlling microbial degradation of dissolved organic matter (DOM) in aquatic environments are poorly understood, although microbes are crucial to global nutrient cycling. Bacterial cell wall components may be one of the keys in understanding the presence of slowly degrading DOM in nature. We found that dominant components of bacterial cell walls (D-amino acids (D-AA), glucosamine (GluA) and diaminopimelic acid (DAPA)) comprised up to 11.4% of the dissolved organic nitrogen in 50 diverse rivers entering the Baltic Sea. Occurrence of DAPA, a characteristic component of Gram-negative (G(-)) bacteria, in the rivers suggests that G(-) bacteria rather than Gram-positive (G(+)) were the major source of the cell wall material. In laboratory studies, the degradation of whole bacterial cells, cell wall material and purified peptidoglycan was studied to characterize degradation of cell wall material by natural aquatic bacteria. Addition of whole killed G(-) and G(+) bacteria to cultures of estuarine bacteria demonstrated fragmentation and loss of cell structure of the G(+) bacteria, while the G(-) bacteria maintained an intact cell shape during the entire 69-day period. In another experiment, estuarine bacteria degraded 39-69% of GluA, D-AA and DAPA in added cell wall material of a representative G(-) bacterial species during 8 days, as compared to a 72-89% degradation of GluA, D-AA and DAPA in cell material of a G(+) bacterial species. When cultures of estuarine bacteria were enriched with purified G(-) and G(+) peptidoglycan (1 mg l(-1)), at least 49% (G(-)) and 58% (G(+)) of D-AA in the peptidoglycan was degraded. No major changes in GluA were obvious. Interpretation of the results was difficult as a portion of the purified peptidoglycan was of similar size to the bacteria and could not be differentiated from cells growing in the cultures. Addition of the purified peptidoglycan stimulated the bacterial growth, and after 6 days the cell density in the enriched cultures was 4-fold higher than in the controls. A regrowth of bacteria after addition of L-broth at 105 days caused a 50- to 75-fold increase in dissolved D-AA and GluA. Most of the D-AA and GluA were taken up during the following 10 days, indicating that cell wall constituents are dynamic compounds. Our results show that a variable portion of peptidoglycan in G(-) and G(+) bacteria can be degraded by natural bacteria, and that peptidoglycan in G(-) bacteria is more resistant to bacterial attack than that in G(+) bacteria. Thus, the presence of cell wall constituents in natural DOM may reflect the recalcitrant nature of especially G(-) peptidoglycan.

Elution behavior of diaminopimelic acid and related diamino acids using the advanced Marfey's method

The advanced Marfey's method consists of a chromatography technique for the separation of amino acids into each enantiomer by derivatization with 1-fluoro-2,4-dinitrophenyl-5-L-leucinamide (L-FDLA), and a detection method using liquid chromatography/mass spectrometry (LC/MS) which can determine the non-empirically the absolute configuration of various amino acids including the non-protein ones. However, this method has not been applied to the determination of the absolute configuration of an amino acid with a "meso" configuration such as diaminopimelic acid (A2pm). In the present study, this method was successfully applied to determine the absolute configurations of diaminosuccinic acid (DAS), A2pm, cystine (Cys), selenocystine (SeCys) and homocystine (HomoCys) using a racemization procedure and the DL-FDLA method, and the resulting elution behavior was summarized as follows: (1) the LL- and meso-isomers were eluted prior to the DD-isomer except for one case; (2) the LL- and meso-isomers are closely eluted and the elution was occasionally reversed; (3) the retention time for both the L- and D-derivatives of the meso-isomer was not changed; (4) the complementary use of the two solvent systems using CH3CN and MeOH was effective to obtain a chromatogram with a high resolution; (5) the abnormality, such as the elution order and peak shape, was observed in the elution behavior of DAS.

Isolates of ‘Candidatus Nostocoida limicola’ Blackall et al. 2000 should be described as three novel species of the genus Tetrasphaera, as Tetrasphaera jenkinsii sp. nov., Tetrasphaera vanveenii sp. nov. and Tetrasphaera veronensis sp. nov

Despite differences in their morphologies, comparative analyses of 16S rRNA gene sequences revealed high levels of similarity (>94 %) between strains of the filamentous bacterium ‘Candidatus Nostocoida limicola’ and the cocci Tetrasphaera australiensis and Tetrasphaera japonica and the rod Tetrasphaera elongata, all isolated from activated sludge. These sequence data and their chemotaxonomic characters, including cell wall, menaquinone and lipid compositions and fingerprints of their 16S–23S rRNA intergenic regions, support the proposition that these isolates should be combined into a single genus containing six species, in the family Intrasporangiaceae in the Actinobacteria. This suggestion receives additional support from DNA–DNA hybridization data and when partial sequences of the rpoC1 gene are compared between these strains. Even though few phenotypic characterization data were obtained for these slowly growing isolates, it is proposed, on the basis of the extensive chemotaxonomic and molecular evidence presented here, that ‘Candidatus N. limicola’ strains Ben 17, Ben 18, Ben 67, Ben 68 and Ben 74 all be placed into the species Tetrasphaera jenkinsii sp. nov. (type strain Ben 74T=DSM 17519T=NCIMB 14128T), ‘Candidatus N. limicola’ strain Ben 70 into Tetrasphaera vanveenii sp. nov. (type strain Ben 70T=DSM 17518T=NCIMB 14127T) and ‘Candidatus N. limicola’ strains Ver 1 and Ver 2 into Tetrasphaera veronensis sp. nov. (type strain Ver 1T=DSM 17520T=NCIMB 14129T).

Streptomyces sp. strain isolated from river water has high bisphenol A degradability

AIMS

We report the identification of the bisphenol A (BPA) biodegradability in Streptomyces sp. strain isolated from river water.

METHODS AND RESULTS

The water samples spiked with BPA (1 mg l(-1)) and the culture solution of Streptomyces sp. strain were placed at 30 degrees C for 10 days and were analysed by high-performance liquid chromatography. A half-life for BPA degradation was between 3 and 4 days. The removal rate of BPA was >90% for 10 days.

CONCLUSIONS

These results show that the Streptomyces sp. strain isolated from river water has high BPA degradability.

SIGNIFICANCE AND IMPACT OF THE STUDY

To our knowledge, this is the first report of BPA degradation by Streptomyces sp. strain.

Resolution of chiral drugs by liquid chromatography based upon diastereomer formation with chiral derivatization reagents

Chiral derivatization reagents for resolution of biologically important compounds, such as chiral drugs by high-performance liquid chromatography (HPLC), based upon pre-column derivatization and diastereomer formation, are reviewed. The derivatization reagents for various functional groups, i.e., amine, carboxyl, carbonyl, hydroxyl and thiol, are evaluated in terms of reactivity, stability, wavelength, handling, versatility, sensitivity, and selectivity. The applicability of the reagents to the analyses of drugs and bioactive compounds are included in the text.