Deinococcus hibisci sp. nov., isolated from rhizosphere of Hibiscus syriacus L. (mugunghwa flower).

A Gram-stain-positive, pink-pigmented, coccus-shaped, strictly aerobic, non-motile bacterium, strain THG-AG1.5T, was isolated from rhizosphere of Hibiscus syriacus L. (Mugunghwa flower) located in Kyung Hee University, Yongin, Gyeonggi, Republic of Korea. The isolated strain grew optimally at 25-30 °C, at pH 6.0-7.5 and in the presence of additional 0-1.5 % (w/v) NaCl. Strain THG-AG1.5T exhibited tolerance to UV radiation (>1500 J m-2) and to gamma radiation (>12 kGy). Based on 16S rRNA gene sequence comparisons, strain THG-AG1.5T was closely related to Deinococcus daejeonensis MJ27T (98.03 %), Deinococcus radiotolerans C1T (97.61 %) and Deinococcus grandis DSM 3963T (97.32 %). The genomic DNA G+C content of strain THG-AG1.5T was 74.8 mol%. The DNA-DNA hybridization values between strain THG-AG1.5T and its closest phylogenetically neighbours were below 63.0 %. The peptidoglycan amino acids were alanine, valine, glutamic acid, glycine, ornithine, lysine and aspartic acid. Strain THG-AG1.5T contained ribose, mannose and glucose as whole-cell-wall sugars and menaquinone-8 (MK-8) as the only isoprenoid quinone. The major component in the polyamine pattern was spermidine. The major polar lipids of strain THG-AG1.5T were a phosphoglycolipid, six unidentified glycolipids and an unidentified aminophospholipid. The major fatty acids were identified as iso-C15 : 0, C15 : 1ω6c, C16 : 0, iso-C17 : 0, C17 : 0, C18 : 0 and summed feature 3. On the basis of our polyphasic taxonomy study, strain THG-AG1.5T represents a novel species within the genus Deinococcus, for which the name Deinococcushibisci sp. nov. is proposed. The type strain is THG-AG1.5T (=KACC 18850T=CCTCC AB 2016078T).

Flavobacterium limi sp. nov., isolated from forest mud.

A Gram-stain-negative, aerobic, non-motile, yellow and rod-shaped bacterial strain was isolated from forest mud located at Kyung Hee University, South Korea. Strain THG-AG6.4T grew at 10-35 °C, pH 6.0-9.5 and in the presence of 0-1.5 % (w/v) NaCl. Phylogenetic analysis, based on 16S rRNA gene sequencing, showed that strain THG-AG6.4T was most closely related to Flavobacterium gyeonganense HME 7524T (97.66 %), Flavobacterium defluvii EMB 117T (96.93 %) and Flavobacterium arsenitoxidans S2-3HT (96.80 %). The DNA G+C content of strain THG-AG6.4T was 30.2 mol%. The DNA-DNA relatedness values between strain THG-AG6.4T and its closest phylogenetic neighbour, F. gyeonganense HME 7524T, were below 61.0 %. The predominant quinone of strain THG-AG6.4T was MK-6. The major polar lipids were phosphatidylethanolamine, an unidentified phospholipid, five unidentified glycolipids, phosphatidylserine, an unidentified lipid, an unidentified aminophospholipid, two unidentified aminolipids and two unidentified aminoglycolipids. The major fatty acids were C16 : 0, C18 : 0 10-methyl, summed feature 3 and C18 : 1ω9c. The major polyamine was homospermidine. On the basis of the phenotypic, genotypic and phylogenetic characterization of strain THG-AG6.4T, it is concluded that the isolate represents a novel species of the genus Flavobacterium, for which the name Flavobacterium limi sp. nov. is proposed, with THG-AG6.4T as the type strain (=KACC 18851T=CGMCC 1.16060T).

Aquaspirillum soli sp. nov., isolated from a soil sample.

A Gram-stain-negative, smooth, opaque, white-pigmented, helical-shaped, catalase- and oxidase-positive bacterium that was motile by means of bipolar tufts of flagella and grew under microaerophilic conditions, was isolated from a soil sample of a reed pond in Shangqiu, Henan province, PR China. The strain, designated THG-SQE6T, grows well at 25-42 °C, pH 6.5-7.5 and in the presence of 0-1 % (w/v) NaCl. hylogenetic analysis based on 16S rRNA gene sequences showed that strain THG-SQE6T was most closely related to Aquaspirillum serpens IAM 13944T (97.23 % 16S rRNA gene sequence similarity). The DNA G+C content of strain THG-SQE6T was 53.10 mol%. In DNA-DNA hybridization experiments, the DNA-DNA relatedness between strain THG-SQE6T and its closest phylogenetic neighbour was below 62.6 %. The predominant isoprenoid quinone detected in strain THG-SQE6T was ubiquinone-8 (Q-8). The major polar lipids were phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol, phosphatidylserine, an unidentified phospholipid, an unidentified aminolipid and two unidentified lipids. The major fatty acids were identified as C12 : 0 3-OH, C16 : 0, C18 : 0, summed feature 3 and summed feature 8. These data support the affiliation of strain THG-SQE6T to the genus Aquaspirillum. Based on findings from the phenotypic, genotypic and phylogenetic characterization of strain THG-SQE6T, a novel species of the genus AquaspirillumnamedAquaspirillum soli sp. nov. is proposed. The type strain is THG-SQE6T (=KACC 18846T=CCTCC AB 2016081T).

Flavobacterium hibisci sp. nov., isolated from the rhizosphere of Hibiscus syriacus L.

A Gram-stain-negative, smooth, bright-yellow-pigmented, rod-shaped bacterial strain, slightly motile by gliding, catalase- and oxidase-positive and aerobic, but growing weakly under anaerobic conditions, was isolated from the rhizosphere of the flower mugunghwa (Hibiscus syriacus L.) located in Kyung Hee University, Yongin, Gyeonggi, South Korea. The strain named THG-HG1.4T grew at 15-35 °C, pH 6.5-9.0 and in the presence of 0-2.5 % (w/v) NaCl. The phylogenetic analysis based on 16S rRNA gene sequence showed that strain THG-HG1.4T was most closely related to Flavobacterium gyeonganense HME7524T (98.83 %) and Flavobacterium arsenitoxidans S2-3HT (97.28 %). The DNA G+C content of strain THG-HG1.4T was 41.2 mol%. In DNA-DNA hybridization, the DNA-DNA relatedness between strain THG-HG1.4T and its closest phylogenetic neighbour was below 64.1 %. The predominant isoprenoid quinone detected in strain THG-HG1.4T was menaquinone-6 (MK-6). The major polar lipids were found to be phosphatidylethanolamine, three unidentified lipids, two unidentified glycolipids and an unidentified aminolipid. The major fatty acids were identified as iso-C15 : 0, iso-C15 : 0 3-OH, C16 : 0, iso-C17 : 0 3-OH and summed feature 3. Thus, based on the report of the phenotypic, genotypic and phylogenetic characterization of strain THG-HG1.4T, it has been concluded that the novel isolate represents a novel species of the genus Flavobacterium.Flavobacterium hibisci sp. nov. is proposed, with THG-HG1.4T (=KACC 18852T=CCTCC AB 2016178T) as the type strain.

Niastellahibisci sp. nov., isolated from rhizosphere soil of mugunghwa, the Korean national flower.

A Gram-stain-negative, aerobic, non-motile, long rods with no flagellum strain, designated THG-YS3.2.1T, was isolated from rhizosphere soil of mugunghwa, collected from Kyung Hee University, Yongin, South Korea. Growth occurred at 10-40 °C (optimum 28 °C), at pH 6.0-8.0 (optimum pH 7.0) and with 0-1.0 % NaCl (optimum 1.0 %). The predominant menaquinone was menaquinone-7 (MK-7). The major cellular fatty acids were anteiso-C12 : 0, iso-C14 : 0, iso-C15 : 0, anteiso-C15 : 0, iso-C15 : 1 G, anteiso-C15 : 1 A, C15 : 0 2-OH, C16 : 0, iso-C16 : 0, C16 : 0 3-OH, iso-C16 : 0 3-OH, iso-C16 : 1 G, C17 : 0 2-OH, iso-C17 : 0 3-OH, C17 : 1ω6c, C18 : 3ω6c (6, 9, 12), C18 : 0, summed feature 3 (C16 : 1ω7c and/or iso-C15 : 0 2-OH). The major polar lipids were phosphatidylmethylethanolamine), phosphatidylethanolamine, five unidentified aminolipids and three unidentified lipids. The DNA G+C content of strain THG-YS3.2.1T was 45.3 mol%. Based on 16S rRNA gene sequence analysis, the nearest phylogenetic neighbours of strain THG-YS3.2.1T were Niastella populi KCTC 22560T (98.7 % 16S rRNA gene sequence similarity), Niastella gongjuensis KACC 17399T (96.9 %), Niastella vici KCTC 42474T (96.2 %), Niastella yeongjuensis KACC 11466T (95.5 %) and Niastella koreensis KACC 11465T (95.1 %). DNA-DNA hybridization values between strain THG-YS3.2.1T and N. populi KCTC 22560T, N. gongjuensis KACC 17399T, N.vici KCTC 42474T, N. yeongjuensis KACC 11466T and N. koreensis KACC 11465Twere 55.8±1.0, 39.5±0.5, 35.2±0.1, 17.6±0.3 and 12.5±1.2 %, respectively. On the basis of the phylogenetic analysis, chemotaxonomic data, physiological characteristics and DNA-DNA hybridization data, strain THG-YS3.2.1T represents a novel species of the genus Niastella, for which the name Niastellahibisci sp. nov. is proposed. The type strain is THG-YS3.2.1T (=KCTC 52084T=CCTCC AB 2015356T).

Lysobacter rhizophilus sp. nov., isolated from rhizosphere soil of mugunghwa, the national flower of South Korea.

A Gram-staining-negative, aerobic, motile, rod-shaped, catalase- and oxidase-negative strain with one polar flagellum, designated THG-YS3.6T, was isolated from rhizosphere soil of a mugunghwa flower collected from Kyung Hee University, Yongin, South Korea. Growth occurred at 10-37 °C (optimum 25-30 °C), at pH 6-8 (optimum 7.0) and with 0-2.0 % NaCl (optimum 1 %). The isoprenoid quinone was ubiquinone-8 (Q-8). The major cellular fatty acids were iso-C11 : 0, iso-C11 : 0 3-OH, iso-C15 : 0, iso-C16 : 0, C16 : 1ω7c alcohol, C16 : 0, iso-C17 : 0 and summed feature 9 (iso-C17 : 1ω9c and/or C16 : 0 10-methyl). The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylmethylethanolamine, phosphatidylethanolamine, one unknown phospholipid, one unknown lipid and three unknown aminolipids. The DNA G+C content of strain THG-YS3.6T was 65.3 mol%. Based on 16S rRNA gene sequence analysis, the nearest phylogenetic neighbours of strain THG-YS3.6T were identified as Lysobacter yangpyeongensis KACC 11407T (98.7 %), Lysobacter oryzae KCTC 22249T (98.0 %), Lysobacter niabensis KACC 11587T (97.6 %) and Lysobacter terrae KACC 17646T (97.1 %). The DNA-DNA relatedness values between strain THG-YS3.6T and L. yangpyeongensis KACC 11407T, L. oryzae KCTC 22249T, L. niabensis KACC 11587T and L. terrae KACC 17646T were 53.8±1.0 %, 12.9±1.2 %, 10.9±0.6 % and 7.0±1.9 %, respectively. On the basis of the phylogenetic analysis, chemotaxonomic data, physiological characteristics and DNA-DNA hybridization data, strain THG-YS3.6T represents a novel species of the genus Lysobacter, for which the name Lysobacter rhizophilus sp. nov. is proposed. The type strain is THG-YS3.6T (=KCTC 52082T=CCTCC AB 2015358T).

Sphingobacterium ginsenosidimutans sp. nov., a bacterium with ginsenoside-converting activity isolated from the soil of a ginseng field.

A Gram-staining-negative, aerobic, non-motile, non-spore-forming, and rod-shaped bacterium designated THG 07(T) was isolated from the soil of a ginseng field of Pocheon in South Korea, and its taxonomic position was investigated by using a polyphasic study. Strain THG 07(T) grew optimally at 25-30°C and at pH 6.5-7.0 and in the absence of NaCl on nutrient agar. Strain THG-T17(T) displayed ß-glucosidase activity that was responsible for its ability to transform ginsenoside Rb1 (one of the dominant ginsenosides of ginseng) to compound C-K. On the basis of 16S rRNA gene sequence similarity, strain THG 07(T) was shown to belong to the family Sphingobacteriaceae and was related to Sphingobacterium canadense CR11(T) (98.7%), S. cladoniae No.6(T) (98.1%), S. detergens 6.2S(T) (98.0%), S. multivorum IAM14316(T) (97.9%), S. siyangense SY1(T) (97.8%) and S. thalpophilum DSM11723(T) (96.9%). The G+C content of the genomic DNA was 40.6 mol%. The major menaquinone, MK-7, and major fatty acids, iso-C15:0 and C16:1 ω7c and/or ω6c, supported the affiliation of strain THG 07(T) to the genus Sphingobacterium. The DNA-DNA relatedness values between strain THG 07(T) and its closest phylogenetic neighbors were below 26.9%. The results of physiological and biochemical tests enabled strain THG 07(T) to be differentiated phenotypically from the recognized species of the genus Sphingobacterium. Therefore the isolate represents a novel species, for which the name Sphingobacterium ginsenosidimutans sp. nov. is proposed, with the type strain THG 07(T) (=KACC 14526(T)=JCM 16722(T)).

Association of colony morphology with coenzyme Q(10) production and its enhancement from Rhizobium radiobacter T6102W by addition of isopentenyl alcohol as a precursor.

Rhizobium radiobacter T6102 was morphologically purified by the aniline blue agar plates to give two distinct colonies; white smooth mucoid colony (T6102W) and blue rough colony (T6102B). The coenzyme Q(10) (CoQ(10)) was produced just by T6102W, showing 2.0 mg/g of CoQ(10) content, whereas the T6102B did not produce the CoQ(10). All of the used CoQ(10) biosynthetic precursors enhanced the CoQ(10) production by T6102W. Specifically, the supplementation of 0.75 mM isopentenyl alcohol improved the CoQ(10) concentration (19.9 mg/l) and content (2.4 mg/g) by 42% and 40%, respectively.

Enhanced production of gamma-aminobutyric acid using rice bran extracts by Lactobacillus sakei B2-16.

An efficient and simple fermentation process was developed for the production of gamma-amminobutyric acid (GABA) by Lactobacillus sakei B2-16. When the L. sakei B2-16 was cultivated in the rice bran extracts medium containing 4% sucrose, 1% yeast extract and 12% monosodium glutamate, the maximum GABA concentration reached 660.0 mM with 100% conversion yield, showing the 2.4-fold higher GABA concentration compared to the modified MRS medium without the rice bran extracts. The GABA production was scaled-up from a laboratory scale (5 L) to a pilot (300 L) and a plant scales (5,000 L) to investigate the application possibility of GABA production to industrial fields. The GABA production at the pilot and plant scales was similar to the laboratory scale using rice bran extracts medium which could be effective for the low-cost production of GABA.

Electrically conductive bacterial cellulose by incorporation of carbon nanotubes.

Electrically conducting polymeric membranes were prepared by incorporating multiwalled carbon nanotubes (MWCNTs) into bacterial cellulose pellicles produced by Gluconacetobacter xylinum. The MWCNTs were dispersed in a surfactant (cationic cetyl trimethylammonium bromide) solution, and cellulose pellicles were dipped into the solution for 6, 12, and 24 h. The surfactants were then extracted in pure water and dried. Electron microscopy showed that the individual MWCNTs were strongly adhered to the surface and the inside of the cellulose pellicle. The conductivity of the MWCNTs-incorporated cellulose pellicle, as measured by a four-probe at room temperature, was 1.4 x 10(-1) S/cm, based on the total cross-sectional area (approximately 9.6 wt % of MWCNTs). This suggests that the MWCNTs were incorporated uniformly and densely into the pellicles.

Simple one-step purification of nisin Z from unclarified culture broth of Lactococcus lactis subsp. lactis A164 using expanded bed ion exchange chromatography.

A simple one-step purification method, using expanded bed, ion-exchange chromatography, for the fractionation of nisin Z produced by Lactococcus lactis subsp. lactis A164 was developed. The highest dynamic binding capacity (0.92) of the adsorbent was obtained at a superficial velocity of 367 cm h(-1), resulting in approx. 2.7-fold bed expansion. The range of pH for the maximum adsorption was 3-4. The isocratic elution with 0.15 M NaCl led to approx. >90% recovery. Single-step purification of nisin Z from unclarified A164 culture broth resulted in 31-fold purification with a 90% yield.

Influence of growth conditions on the production of a nisin-like bacteriocin by Lactococcus lactis subsp. lactis A164 isolated from kimchi.

The influence of growth parameters on the fermentative production of a nisin-like bacteriocin by Lactococcus lactis subsp. lactis A164 isolated from kimchi was studied. The bacteriocin production was greatly affected by carbon and nitrogen sources. Strain A164 produced at least 4-fold greater bacteriocin in M17 broth supplemented with lactose than other carbon sources. The amount of 3% yeast extract was found to be the optimal organic nitrogen source. While the maximum biomass was obtained at 37 degrees C, the optimal temperature for the bacteriocin production was 30 degrees C. The bacteriocin production was also affected by pH of the culture broth. The optimal pH for growth and bacteriocin production was 6.0. Although the cell growth at pH 6.0 was nearly the same level at pH 5.5 and 6.5, the greater bacteriocin activity was observed at pH 6.0. Exponential growth took place only during an initial period of the cultivation, and then linear growth was observed. Linear growth rates increased from 0.160 g(DCW) x l(-1) x h(-1) to 0.245 g(DCW) x l(-1) x h(-1) with increases in lactose concentrations from 0.5 to 3.0%. Maximum biomass was also increased from 1.88 g(DCW) x l(-1) to 4.29 g(DCW) x l(-1). However, increase in lactose concentration did not prolong the active growth phase. After 20 h cultivation, cell growth stopped regardless of lactose concentration. Production of the bacteriocin showed primary metabolic kinetics. However, bacteriocin yield based on cell mass increased greatly during the late growth phase. A maximum activity of 131x10(3) AU x ml(-1) was obtained at early stationary growth phase (20 h) during the batch fermentation in M17L broth (3.0% lactose) at 30 degrees C and pH 6.0.