Selection of a Photosynthetic Bacterium Suitable for Hydrogen Production in Outdoor Cultures among Strains Isolated in the Seoul,Taegu, Sendai and Bangkok Areas

Very efficient hydrogen producing photosynthetic bacteria, strains SL1, SL3, SL16 and TG28 newly isolated in Korea, and strain KM113 newly isolated in the Sendai area, were found to be Rhodopseudomonas spp. To examine the stability of cell suspensions of the cultures for hydrogen production, which is closely associated with light absorption, we conducted larger scale cultures under periodic illumination (12-hr intervals) without stirring at 30°C using strains SL1 and Rhodopseudomonas sphaeroides B5, the latter was isolated in the Bangkok area. Both strains gave homogeneous cell suspensions throughout the incubation period and larger amounts of hydrogen were produced in a shorter period of time by both cultures than obtained with Rhodopseudomonas sp. TN3, an isolate from the Sendai area which was reported previously. With the cells of the new isolates and strains TN3 and B5 grown on glutamate-malate medium at 30°C, we measured hydrogen production at 20, 30 and 40°C in the same medium. Among them, strains SL1, SL16 and KM113 showed the highest hydrogen production activity at 30°C. The maximum hydrogen production rates with these strains were over 130 µ1/hr/mg dry cells, but at 40°C, the highest activity (138 µl/hr/mg dry cells) was obtained with strain B5. Since strain B5 also showed good activities at 20 and 30°C, we suggest that this strain might be suitable for hydrogen production in outdoor cultures.     

Themoanaerobacterium calidifontis sp. nov., a novel anaerobic, thermophilic, ethanol-producing bacterium from hot springs in China

A novel thermophilic Gram staining positive strain Rx1 was isolated from hot springs in Baoshan of Yunnan Province, China. The strain was characterized as a hemicellulose-decomposing obligate anaerobe bacterium that is rod-shaped (diameter: 0.5–0.7 μm; length: 2.0–6.7 μm), spore-forming, and motile. Its growth temperature range is 38–68 °C (optimum 50–55 °C) and pH range is 4.5–8.0 (optimum 7.0). The maximum tolerance concentration of NaCl was 3 %. Rx1 converted thiosulfate to elemental sulfur and reduced sulfite to hydrogen sulfide. The bacterium grew by utilizing xylan and starch, as well as a wide range of monosaccharide and polysaccharides, including glucose and xylose. The main products of fermentation were ethanol, lactate, acetate, CO₂, and H₂. The maximum xylanase activity in the culture supernatant after 30 h of incubation at 55 °C was 16.2 U/ml. Rx1 DNA G + C content was 36 mol %. 16S rRNA gene sequence analysis indicated that strain Rx1 belonged to the genus Thermoanaerobacterium of the family ‘Thermoanaerobacteriaceae’ (Firmicutes), with Thermoanaerobacterium aciditolerans 761–119 (99.2 % 16S rRNA gene sequence similarity) being its closest relative. DNA–DNA hybridization between Rx1 and T. aciditolerans 761–119 showed 36 % relatedness. Based on its physiological and biochemical tests and DNA–DNA hybridization analyses, the isolate is considered to represent a novel species in the genus Thermoanaerobacterium, for which the name Thermoanaerobacterium calidifontis sp. nov. is proposed, with the type strain is Rx1 (=JCM 18270 = CCTCC M 2011109).     

Geodermatophilus africanus sp. nov., a halotolerant actinomycete isolated from Saharan desert sand

A novel Gram-strain positive, aerobic, actinobacterial strain, designated CF11/1^T, was isolated from a sand sample obtained in the Sahara Desert, Chad. The black-pigmented isolate was aerobic and exhibited optimal growth from 25 to 35 °C at pH 6.0–8.0 and with 0–8 % (w/v) NaCl, indicating that it is a halotolerant mesophile. Chemotaxonomic and molecular characteristics of the isolate matched those described for members of the genus Geodermatophilus. The G+C content in the genome was 74.4 mol%. The peptidoglycan contained meso-diaminopimelic acid as diagnostic diaminoacid. The main phospholipids were diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol and a minor fraction of phosphatidylglycerol; MK-9(H₄) was the dominant menaquinone, and galactose was detected as a diagnostic sugar. The major cellular fatty acid was branched-chain saturated acid iso-C_16:0. Analysis of 16S rRNA gene sequences showed 95.3–98.6 % pairwise sequence identity with the members of the genus Geodermatophilus. Based on phenotypic and chemotaxonomic properties, as well as phylogenetic distinctiveness, the isolate represents a novel species, Geodermatophilus africanus, with the type strain CF11/1^T (DSM 45422 = CCUG 62969 = MTCC 11556).     

Marinobacter persicus sp. nov., a moderately halophilic bacterium from a saline lake in Iran

A Gram-negative, non-endospore-forming, rod shaped, strictly aerobic, moderately halophilic bacterium, designated strain M9B^T, was isolated from the hypersaline lake Aran-Bidgol in Iran. Cells of strain M9B^T were found to be motile and produce colonies with an orange-yellow pigment. Growth was determined to occur between 5 and 20 % (w/v) NaCl and the isolate grew optimally at 7.5–10 % (v/w) NaCl. The optimum pH and temperature for growth of the strain were determined to be pH 7.0 and 35 °C, respectively, while it was able to grow over pH and temperature ranges of 6–8 and 25–45 °C, respectively. Phylogenetic analysis based on the comparison of 16S rRNA gene sequences revealed that strain M9B^T is a member of the genus Marinobacter. The closest relative to this strain was found to be Marinobacter hydrocarbonoclasticus MBIC 1303^T with a similarity level of 97.7 %. DNA–DNA hybridization between the novel isolate and this phylogenetically related species was 13 ± 2 %. The major cellular fatty acids of the isolate were identified as C_16:0, C_19:1 ω6c, C_18:1 ω9c and C_16:1 ω9c. The polar lipid pattern of strain M9B^T was determined to consist of phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylserine and three phospholipids. Ubiquinone 9 (Q-9) was the only lipoquinone detected. The G+C content of the genomic DNA of this strain was determined to be 58.6 mol%. Phenotypic characteristics, phylogenetic analysis and DNA–DNA relatedness data suggest that this strain represents a novel species of the genus Marinobacter, for which the name Marinobacter persicus sp. nov. is proposed. The type strain of Marinobacter persicus is strain M9B^T (=IBRC-M 10445^T = CCM 7970^T = CECT 7991^T = KCTC 23561^T).     

Tenuibacillus halotolerans sp. nov., a novel bacterium isolated from a soil sample from a salt lake in Xinjiang, China and emended description of the genus Tenuibacillus

A Gram-positive, moderately halotolerant, rod-shaped bacterium, designated YIM 94025^T, was isolated from a soil sample from a salt lake in Xinjiang province, north-west China. Strain YIM 94025^T was observed to grow at 25–45 °C (optimum 37 °C), 0–22 % NaCl (optimum 2–10 %) and pH 6.0–9.0 (optimum pH 8.0). Phylogenetic analyses based on 16S rRNA gene sequences revealed that the organism belongs to the genus Tenuibacillus and exhibited sequence similarity of 98.0 % to the closest type strain, Tenuibacillus multivorans AS 1.3442^T. The predominant menaquinone was found to be MK-7; the cell-wall peptidoglycan diamino acid was meso-diaminopimelic acid; the polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, an unidentified phospholipid and an unknown lipid; and the major fatty acids were found to contain iso-C_15:0, anteiso-C_15:0 and iso-C_16:0. The chemotaxonomic characteristics of strain YIM 94025^T are consistent with those of the genus Tenuibacillus. The level of DNA–DNA relatedness value between YIM 94025^T and T. multivorans AS 1.3442^T was 36.6 ± 4.5 %. The G+C content of the strain YIM 94025^T was determined to be 38.5 %. Based on the comparative analysis of physiological, biochemical and chemotaxonomic data, as well as DNA–DNA hybridization results, the isolate is considered to represent a novel species of the genus Tenuibacillus, for which the name Tenuibacillus halotolerans sp. nov., is proposed, with the type strain of YIM 94025^T (=CCTCC AB 2012860^T = KCTC 33046^T).     

<Emphasis Type="Italic">Burkholderia alba</Emphasis> sp. nov., isolated from a soil sample on Halla mountain in Jeju island

A rod-shaped, round and white colony-forming strain AD18^T was isolated from the soil on Halla mountain in Jeju Island, Republic of Korea. Comparative analysis of 16S rRNA gene sequence revealed that this strain was closely related to Burkholderia oklahomensis C6786^T (98.8%), Burkholderia thailandensis KCTC 23190^T (98.5%). DNA-DNA relatedness (14.6%) indicated that the strain AD18^T represents a distinct species that is separate from B. oklahomensis C6786^T. The isolate grew at pH 5.0–9.0 (optimum, pH 7.0), 0–3% (w/v) NaCl (optimum, 0%), and temperature 10–40°C (optimum 35°C). The sole quinone of the strain was Q-8, and the predominant fatty acids were C_16:0, C_17:0 cyclo, and C_19:0 cyclo ω8c. The genomic DNA G + C content of AD18T was 65.6 mol%. Based on these findings, strain AD18^T is proposed to be a novel species in the genus Burkholderia, for which the name Burkholderia alba sp. nov. is proposed (= KCCM 43268^T = JCM 32403^T). The type strain is AD18^T.     

Streptomyces bullii sp. nov., isolated from a hyper-arid Atacama Desert soil

A Streptomyces strain isolated from a hyper-arid Atacama Desert soil was characterised using a polyphasic taxonomic approach. The strain, designated C2^T, had chemical and morphological properties typical of the genus Streptomyces. The isolate formed a branch in the Streptomyces 16S rRNA gene tree together with the type strain of Streptomyces chromofuscus and was also loosely related to Streptomyces fragilis NRRL 2424^T. DNA:DNA relatedness values between the isolate and its two phylogenetic neighbours showed that it formed a distinct genomic species. The strain was readily distinguished from these organisms using a combination of morphological and phenotypic data. Based on the genotypic and phenotypic results, isolate C2^T represents a novel species in the genus Streptomyces, for which the name Streptomyces bullii sp. nov. is proposed. The type strain is C2^T (=CGMCC 4.7019^T = KACC 15426^T).     

Methanohalophilus profundi sp. nov., a methylotrophic halophilic piezophilic methanogen isolated from a deep hypersaline anoxic basin

A novel anaerobic methylotrophic halophilic methanogen strain SLHTYRO^T was isolated from a deep hypersaline anoxic basin called “Tyro” located in the Eastern Mediterranean Sea. Cells of SLHTYRO^T were motile cocci. The strain SLHTYRO^T grew between 12 and 37 °C (optimum 30 °C), at pH between 6.5 and 8.2 (optimum pH 7.5) and salinity from 45 to 240 g L⁻¹ NaCl (optimum 135 g L⁻¹). Strain SLHTYRO^T was methylotrophic methanogen able to use methylated compounds (trimethylamine, dimethylamine, monomethylamine and methanol). Strain SLHTYRO^T was able to grow at in situ hydrostatic pressure and temperature conditions (35 MPa, 14 °C). Phylogenetic analysis based on 16S rRNA gene and mcrA gene sequences indicated that strain SLHTYRO^T was affiliated to genus Methanohalophilus within the order Methanosarcinales. It shared >99.16% of the 16S rRNA gene sequence similarity with strains of other Methanohalophilus species. Based on ANIb, AAI and dDDH measurements, and the physiological properties of the novel isolate, we propose that strain SLHTYRO^T should be classified as a representative of a novel species, for which the name Methanohalophilus profundi sp. nov. is proposed; the type strain is SLHTYRO^T (=DSM 108854 = JCM 32768 = UBOCC-M-3308).     

Roseomonas musae sp. nov., a new bacterium isolated from a banana phyllosphere

A Gram-negative, coccobacilli, non-spore forming and non-motile bacterium, designated PN1^T, was isolated from a banana leaf collected in Mattra island, Thailand. This isolate was observed to grow optimally at 30 °C and pH 7.0, and to grow with 0–3 % NaCl. Comparative 16S rRNA gene sequence analysis showed that strain PN1^T is closely related to members of the genus Roseomonas, exhibiting the highest 16S rRNA gene sequence similarity to Roseomonas aestuarii JC17^T (96.5 %). The DNA G + C content of strain PN1^T was determined to be 69.7 mol %. Based on physiological and biochemical tests, and genotypic differences between strain PN1^T and the validly named species of the genus Roseomonas, it is proposed that the strain be classified as a new species of Roseomonas for which the name Roseomonas musae sp. nov. is proposed. The type strain is PN1^T (= BCC 44863^T = NBRC 107870^T).     

R-enantioselective hydrolysis of 2,2-dimethylcyclopropanecarboxamide by amidase from a newly isolated strain Brevibacterium epidermidis ZJB-07021

Aims: To isolate new micro-organisms with R-stereospecific amidase activity and to examine their potential as biocatalysts in enantioselective hydrolysis of 2,2-dimethylcyclopropanecarboxamide ( 1 ). Methods and Results: A novel R-stereospecific amidase-producing strain ZJB-07021 was isolated through a sophisticated colorimetric screening method. Based on morphology, physiological tests, Biolog system (GP2) and 16S rRNA sequence, the new isolate was identified as Brevibacterium epidermidis. After 70 min of bioconversion at 35°C, kinetic resolution of (R,S)- 1 by the amidase afforded (S)- 1 in 41·1% yield (>99% ee) and (R)- 2 in 49·9% yield (69·7% ee) with an average E-value of 23. The enantioselectivity was found to be temperature dependent and enhanced from 12·6 at 45°C to 65·9 at 14°C. Conclusions: A novel bacterial strain of B. epidermidis ZJB-07021 producing R-stereospecific amidase was isolated and characterized. The isolate exhibited high E values for kinetic resolution of racemic- 1 to (S)- 1 . Significance and Impact of the Study: To our knowledge, this was the first report on the species B. epidermidis that harboured R-stereospecific amidase. Strain ZJB-07021 could be further improved as a suitable biocatalyst for the stereoselective bioconversion of racemic- 1 after optimization of culture and biotransformation process.     

Extracellular lipase from <Emphasis Type="Italic">Pseudomonas aeruginosa</Emphasis> JCM5962(T): Isolation,identification, and characterization

The study was done to isolate, identify, and characterize a good lipolytic strain from soil. Lipolytic strain isolation was done using tributyrin agar medium. The biochemical testing and 16S rRNA gene sequencing analysis was done for identification. The enzyme was purified using ammonium sulfate precipitation and column chromatography. Results have shown a novel high lipolytic strain of P. aeruginosa JCM5962(T), isolated from soil of sugarcane field. The 16S rRNA sequence analysis confirmed the strain as P. aeruginosa JCM5962(T); further, the sequence was submitted to Genbank (KX946966.1). The isolate produced an extracellular lipase which was purified as single band of 31 kDa. Maximum lipase activity was observed at 50 °C and pH 8.0. Activity was enhanced in the presence of cobalt and benzene solvent, whereas mercury, sodium dodecyl sulfate, and chloroform inhibited it. The enzyme’s marked stability and activity at high temperature, alkaline pH and organic solvents suggest that this can be effectively used in a variety of applications in industries and as biotechnological tools.     

DNA supercoiling in a thermotolerant mutant ofEscherichia coli

A spontaneously occurring, nalidixic acid-resistant (Nal^R), thermotolerant (T/r) mutant ofEscherichia coli was isolated. Bacteriophage P1-mediated transduction showed that Nal^R mapped at or neargyr A, one of the two genes encoding DNA gyrase. Expression ofgyrA ⁺ from a plasmid rendered the mutant sensitive to nalidixic acid and to high temperature, the result expected for alleles mapping ingyrA. Plasmid linking number measurements, made with DNA from cells grown at 37° C or shifted to 48° C, revealed that supercoiling was about 12% less negative in the T/r mutant than in the parental strain. Each strain preferentially expressed two different proteins at 48° C. The genetic and supercoiling data indicate that thermo-tolerance can arise from an alteration in DNA gyrase that lowers supercoiling. This eubacterial study, when. coupled with those of archaebacteria, suggests that DNA relaxation is a general aspect of thermotolerance.     

Thermococcus alcaliphilus sp. nov., a new hyperthermophilic archaeum growing on polysulfide at alkaline pH

A novel coccoid-shaped, hyperthermophilic, heterotrophic member of the archaea was isolated from a shallow marine hydrothermal system at Vulcano Island, Italy. The isolate grew between 56 and 90° C with an optimum around 85° C. The pH range for growth was 6.5 to 10.5, with an optimum around 9.0. Polysulfide and elemental sulfur were reduced to H₂S. Sulfur stimulated the growth rate. The isolate fermented yeast extract, peptone, meat extract, tryptone, and casein. Isovalerate, isobutyrate, propionate, acetate, CO₂, NH₃, and H₂S (in the presence of S°) were detected as end products. Growth was not inhibited by H₂. Based on DNA-DNA hybridization and 16S rRNA partial sequences, the new isolate represents a new species of Thermococcus, which we named Thermococcus alcaliphilus. The type strain is isolate AEDII12 (DSM 10322) Received: 7 July 1995 / Accepted: 25 August 1995     

<Emphasis Type="Italic">Virgibacillus kimchii</Emphasis> sp. nov., a halophilic bacterium isolated from kimchi

A Gram-stain-positive, halophilic, rod-shaped, non-motile, spore forming bacterium, strain NKC1-2^T, was isolated from kimchi, a Korean fermented food. Comparative analysis based on 16S rRNA gene sequence demonstrated that the isolated strain was a species of the genus Virgibacillus. Strain NKC1-2^T exhibited high level of 16S rRNA gene sequence similarity with the type strains of Virgibacillus xinjiangensis SL6-1^T (96.9%), V. sediminis YIM kkny3^T (96.8%), and V. salarius SA-Vb1^T (96.7%). The isolate grew at pH 6.5–10.0 (optimum, pH 8.5–9.0), 0.0–25.0% (w/v) NaCl (optimum, 10–15% NaCl), and 15–50°C (optimum, 37°C). The major menaquinone in the strain was menaquinone-7, and the main peptidoglycan of the strain was meso-diaminopimelic acid. The predominant fatty acids of the strain were iso-C_14:0, anteisio-C_15:0, iso- C_15:0, and iso-C_16:0 (other components were < 10.0%). The polar lipids consisted of diphosphatidylglycerol and phosphatidylglycerol. The genomic DNA G + C content of NKC1-2^T was 42.5 mol%. On the basis of these findings, strain NKC1-2^T is proposed as a novel species in the genus Virgibacillus, for which the name Virgibacillus kimchii sp. nov. is proposed (=KACC 19404^T =JCM 32284^T). The type strain of Virgibacillus kimchii is NKC1-2T.     

Geodermatophilus saharensis sp. nov., isolated from sand of the Saharan desert in Chad

A novel Gram-positive, aerobic, actinobacterial strain, CF5/5, was isolated from soil in the Sahara desert, Chad. It grew best at 20–35 °C and at pH 6.0–8.0 and with 0–4 % (w/v) NaCl, forming black-colored colonies. Chemotaxonomic and molecular characteristics of the isolate matched those described for members of the genus Geodermatophilus. The DNA G + C content was 75.9 mol%. The peptidoglycan contained meso-diaminopimelic acid; galactose and xylose were detected as diagnostic sugars. The main phospholipids were diphosphatidylglycerol, phosphatidylcholine, and phosphatidylinositol; MK-9(H₄) was the dominant menaquinone. The major cellular fatty acids were: iso-C_16:0 and iso-C_15:0. The 16S rRNA gene showed 95.6–98.3 % sequence similarity with the other named members of the genus Geodermatophilus. Based on the polyphasic taxonomy data, the isolate is proposed to represent a novel species, Geodermatophilus saharensis with the type strain CF5/5^T = DSM 45423 = CCUG 62813 = MTCC 11416.     

Isolation and characterisation of moderately halophilic bacteriumHalomonas ventosae DL7 synthesizing ectoine as compatible solute

A moderately halophilic Gram-negative bacterium, strain DL7, was isolated from saltern sediment of Dalian, China. Phylogenetic analysis based on 16S rRNA gene sequences indicated that this isolate belongs to the genusHalomonas. Based on the taxonomic and DNA sequence in addition to high DNA-DNA homologies, we concluded that this strain was similar with the type strain ofHalomonas ventosae. Ectoine, one of the representative compatible solutes, was mainly detected in the cells as a result of¹H- and¹³C-NMR measurements when grown in the presence of wide concentration ranges of NaCl. The results showed that higher amount of ectoine was synthesized in a shorter incubation time compared with those of other strains reported earlier.     

Wohlfahrtiimonas larvae sp. nov., isolated from the larval gut of Hermetia illucens (Diptera: Stratiomyidae)

A novel, Gram-negative, facultative anaerobic, motile and short rod-shaped bacterium, strain KBL006^T was isolated from the larval gut of Hermetia illucens, Black soldier fly. The 16S rRNA gene sequence of strain KBL006^T showed 96.4 % similarity to that of Wohlfahrtiimonas chitiniclastica S5^T. Strain KBL006^T grew optimally at 30 °C, at pH 8.0 and in the presence of 1–2 % (w/v) NaCl. Oxidase activity and catalase activity were positive. The major fatty acids were C_18:1 ω7c, C_14:0, and C_16:0. The major respiratory quinone was ubiquinone-8 (Q-8). The major polar lipids were phosphatidylethanolamine, phosphatidylglycerol, and diphosphatidylglycerol, and two phospholipids. The G+C content of the genomic DNA was 45.2 mol%. Based on these polyphasic data, strain KBL006^T is considered to represent a novel species in the genus Wohlfahrtiimonas, for which the name Wohlfahrtiimonas larvae sp. nov. is proposed. The type strain is KBL006^T (= KACC 16839^T = JCM 18424^T).