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1.
Pseudomonas psychrophila HA-4 is a cold-adaptable, sulfamethoxazole-degrading bacterium. The genes related to its cold adaptation mechanism and sulfamethoxazole metabolism were unknown. We present the draft genome of strain HA-4. It could provide further insight into the sulfamethoxazole-degrading mechanism of strain HA-4.  相似文献   

2.
A cold-adapted lipase producing bacterium, designated SS-33T, was isolated from sea sediment collected from the Bay of Bengal, India, and subjected to a polyphasic taxonomic study. Strain SS-33T exhibited the highest 16S rRNA gene sequence similarity with Staphylococcus cohnii subsp. urealyticus (97.18 %), Staphylococcus saprophyticus subsp. bovis (97.16 %) and Staphylococcus cohnii subsp. cohnii (97.04 %). Phylogenetic analysis based on the 16S rRNA gene sequences showed that strain SS-33T belongs to the genus Staphylococcus. Cells of strain SS-33T were Gram-positive, coccus-shaped, non-spore-forming, non-motile, catalase-positive and oxidase-negative. The major fatty acid detected in strain SS-33T was anteiso-C15:0 and the menaquinone was MK-7. The genomic DNA G + C content was 33 mol%. The DNA-DNA hybridization among strain SS-33T and the closely related species indicated that strain SS-33T represents a novel species of the genus Staphylococcus. On the basis of the morphological, physiological and chemotaxonomic characteristics, the results of phylogenetic analysis and the DNA-DNA hybridization, a novel species is proposed for strain SS-33T, with the name Staphylococcus lipolyticus sp. nov. The strain type is SS-33T (=MTCC 10101T?=?JCM 16560T). Staphylococcus lipolyticus SS-33T hydrolyzed various substrates including tributyrin, olive oil, Tween 20, Tween 40, Tween 60, and Tween 80 at low temperatures, as well as mesophilic temperatures. Lipase from strain SS-33T was partially purified by acetone precipitation. The molecular weight of lipase protein was determined 67 kDa by SDS-PAGE. Zymography was performed to monitor the lipase activity in Native-PAGE. Calcium ions increased lipase activity twofold. The optimum pH of lipase was pH 7.0 and optimum temperature was 30 °C. However, lipase exhibited 90 % activity of its optimum temperature at 10 °C and became more stable at 10 °C as compared to 30 °C. The lipase activity and stability at low temperature has wide ranging applications in various industrial processes. Therefore, cold-adapted mesophilic lipase from strain SS-33T may be used for industrial applications. This is the first report of the production of cold-adapted mesophilic lipase by any Staphylococcus species.  相似文献   

3.
The biodegradation of furfuryl alcohol (FA) in shake flask experiments using a pure culture of Pseudomonas putida (MTCC 1194) and Pseudomonas aeruginosa (MTCC 1034) was studied at 30 °C and pH 7.0. Experiments were performed at different FA concentrations ranging from 50 to 500 mg/l. Before carrying out the biodegradation studies, the bacterial strains were acclimatized to the concentration of 500 mg/l of FA by gradually raising 100 mg/l of FA in each step. The well acclimatized culture of P. putida and P. aeruginosa degraded about 80 and 66% of 50 mg/l FA, respectively. At higher concentration of FA, the percentage of FA degradation decreased. The purpose of this study was to determine the kinetics of biodegradation of FA by measuring biomass growth rates and concentration of FA as a function of time. Substrate inhibition was calculated from experimental growth parameters using the Haldane equation. Data for P. putida were determined as µ max ?=?0.23 h?1, K s ?=?23.93 mg/l and K i ?=?217.1 mg/l and for P. aeruginosa were determined as µ max ?=?0.13 h?1, K s ?=?21.3 mg/l and K i ?=?284.9 mg/l. The experimental data were fitted in Haldane, Aiba and Edwards inhibition models.  相似文献   

4.
An enrichment culture method was applied to the isolation of a bacterial strain responsible for biodegradation of methidathion residues, from a methidathion-treated orchard. The strain (SPL-2) was identified as Serratia sp. according to its physiological characteristics and 16S rRNA gene phylogenetic analysis. Serratia sp. was able to grow in a poor medium consisting of mineral salts and using methidathion as the sole carbon source at a concentrations of 50–150 mg/L. The effects of multifactors on degradation of methidathion in pure cultures by Serratia sp. were investigated using an orthogonal experimental design L9 (34). On the basis of range analysis and ANOVA results, the most significant factors were temperature and inoculum size. The optimal conditions for methidathion biodegradation in pure cultures were a temperature in 30 °C, an inoculum size of 10 %, pH?=?7 and an aeration rate of 200 rpm. Two different concentrations of strain SPL-2 fermenting liquids (OD600?=?0.2 and OD600?=?0.4) were prepared and applied to remove methidathion residues from agricultural products, and this process can be described by a first order rate model. In contrast to controls, the DT50 of methidathion was shortened by 35.7 %, 8.2 % and by 62.3 %, 57.5 % on OD600?=?0.2 and OD600?=?0.4 treated haricot beans and peaches, respectively. These results suggest that the isolated bacterial strain may have potential for use in bioremediation of methidathion-contaminated crops.  相似文献   

5.
Conversion of lactose into ethyl acetate by Kluyveromyces marxianus allows economic reuse of whey-borne sugar. The high volatility of ethyl acetate enables its process-integrated recovery by stripping. This stripping is governed by both the aeration rate and the partition coefficient, K EA,L/G. Cultivation at elevated temperatures should decrease the K EA,L/G value and thus favor stripping. K. marxianus DSM 5422 as a potent producer of ethyl acetate was cultivated aerobically in whey-borne media for studying temperature-dependent growth and ester formation. Shake flask cultivation proved thermal tolerance of this yeast growing from 7 to 47 °C with a maximum rate of 0.75 h?1 at 40 °C. The biomass yield was 0.41 g/g at moderate temperatures while low and high temperatures caused distinct drops. The observed μ-T and Y X/S-T dependencies were described by mathematical models. Further cultivations were done in an 1-L stirred reactor for exploring the effect of temperature on ester synthesis. Cultivation at 32 °C caused significant ester formation (Y EA/S?=?0.197 g/g) while cultivation at 42 °C suppressed ester synthesis (Y EA/S?=?0.002 g/g). The high temperature affected metal dissolution from the bioreactor delivering iron for yeast growth and preventing ester synthesis. Cultivation at 32 °C with a switch to 42 °C at the onset of ester synthesis allowed quick and efficient ester production (Y EA/S?=?0.289 g/g). The high temperature lowered the K EA,L/G value from 78 to 44 L/L which heightened the gas-phase ester concentration (favoring ester recovery) without increasing the liquid-phase concentration (avoiding product inhibition).  相似文献   

6.
A bacterial strain C21 isolated from constructed wetland soil was identified as Arthrobacter sp. based on 16S rRNA gene sequence analysis and physio-biochemical characteristics and was capable of utilizing di-n-butyl phthalate (DBP) as a carbon and energy source for growth. Strain C21 can also utilize other phthalates (PAEs) up to a molecular weight of 390.56 and phthalic acid (PA). The biodegradability of these compounds decreased with the increase in the length of phthalate alkyl chains and molecular weight. Kinetic analysis indicated that the strain C21 cell growth on DBP fitted well with Haldane-Andrews’ model (R 2?>?0.98) with μ max, K s, and K i of 0.12/h, 4.2 mg/L, and 204.6 mg/L, respectively. When the initial DBP concentration was lower than 100 mg/L, DBP biodegradation reaction fitted with the first-order kinetics. The results suggested that Arthrobacter strain C21 played an active role in the bioremediation of the wetland contaminated with phthalates.  相似文献   

7.
A Gram-negative, aerobic, non-motile and ovoid or rod-shaped bacterial strain, GGW-M5T, was isolated from seawater on the southern coast in Korea, and its taxonomic position was investigated by using a polyphasic approach. Strain GGW-M5T grew optimally at pH 7.0–8.0, at 30 °C and in the presence of 2 % (w/v) NaCl. A neighbour-joining phylogenetic tree based on 16S rRNA gene sequences revealed that strain GGW-M5T belonged to the genus Glaciecola, joining the cluster comprising the type strains of G. agarilytica, G. arctica, G. chathamensis, G. mesophila, G. polaris and G. psychrophila, with which it exhibited 16S rRNA gene sequence similarity values of 95.9–96.7 %. Strain GGW-M5T exhibited sequence similarity values of 93.2–94.8 % to the type strains of the other Glaciecola species. Strain GGW-M5T contained Q-8 as the predominant ubiquinone and C16:1 ω7c and/or iso-C15:0 2-OH, C16:0 and C14:0 2-OH as the major fatty acids. Major polar lipids were phosphatidylglycerol, phosphatidylethanolamine and diphosphatidylglycerol. The DNA G+C content was 42.4 mol%. Differential phenotypic properties, together with the phylogenetic distinctiveness, demonstrated that strain GGW-M5T could be distinguished from other Glaciecola species. On the basis of the data presented, strain GGW-M5T is considered to represent a novel species of the genus Glaciecola, for which the name Glaciecola aquimarina sp. nov. is proposed. The type strain is GGW-M5T (=KCTC 32108T = CCUG 62918T).  相似文献   

8.
9.
10.
A novel cold-adapted lipolytic enzyme gene, est97, was identified from a high Arctic intertidal zone sediment metagenomic library. The deduced amino acid sequence of Est97 showed low similarity with other lipolytic enzymes, the maximum being 30 % identity with a putative lipase from Vibrio caribbenthicus. Common features of lipolytic enzymes, such as the GXSXG sequence motif, were detected. The gene product was over-expressed in Escherichia coli and purified. The recombinant Est97 (rEst97) hydrolysed various ρ-nitrophenyl esters with the best substrate being ρ-nitrophenyl hexanoate (K m and k cat of 39 μM and 25.8 s?1, respectively). This esterase activity of rEst97 was optimal at 35 °C and pH 7.5 and the enzyme was unstable at temperatures above 25 °C. The apparent melting temperature, as determined by differential scanning calorimetry was 39 °C, substantiating Est97 as a cold-adapted esterase. The crystal structure of rEst97 was determined by the single wavelength anomalous dispersion method to 1.6 Å resolution. The protein was found to have a typical α/β-hydrolase fold with Ser144-His226-Asp197 as the catalytic triad. A suggested, relatively short lid domain of rEst97 is composed of residues 80–114, which form an α-helix and a disordered loop. The cold adaptation features seem primarily related to a high number of methionine and glycine residues and flexible loops in the high-resolution structures.  相似文献   

11.
Strain 16F3HT, a Gram-negative, aerobic, non-motile, and oval-shaped bacterium, was isolated from river water collected from the Han River in South Korea. Growth of strain 16F3HT was observed at 10–42 °C (optimum at 25–30 °C), but no growth occurred at 4 °C. The strain is able to grow at pH 4–10 (optimum at pH 7–8) and tolerates up to 4% NaCl (w/v), with optimum growth at 0.5% NaCl. The isolate was found to be resistant to UV irradiation. Based on 16S rRNA gene sequence analysis, it is closely related to ‘Deinococcus seoulensis’ 16F1E (98.8%), Deinococcus aquaticus PB314T (98.1%) and Deinococcus caeni Ho-08T (98.0%). The level of DNA–DNA homology between the novel strain and the three related strains was 57.4, 41.2, and 35.8%, respectively. Chemotaxonomic data revealed that strain 16F3HT possesses MK-8 as the predominant respiratory quinone, an unidentified phosphoglycolipid as the major polar lipid, and C15:1 ω6c and C16:1 ω7c as the major fatty acids. The DNA G + C content was determined to be 65.7 mol%. Based on polyphasic evidence, strain 16F3HT (=KCTC 33794T = JCM 31406T) should be classified as the type strain of a novel Deinococcus species, for which the name Deinococcus knuensis sp. nov. is proposed.  相似文献   

12.
The only available genome sequence for Rhizopus oryzae strain 99-880 was annotated to not encode any β-1,4-endoxylanase encoding genes of the glycoside hydrolase (GH) family 10 or 11. Here, we report the identification and cloning of two such members in R. oryzae strain NRRL 29086. Strain 29086 was one of several selected fungi grown on wheat or triticale bran and screened for xylanase activity among other hydrolytic actions. Its high activity (138 U/ml) in the culture supernatant led to the identification of two activity-stained proteins, designated Xyn-1 and Xyn-2 of respective molecular masses 32,000 and 22,000. These proteins were purified to electrophoretic homogeneity and characterized. The specific activities of Xyn-1 and Xyn-2 towards birchwood xylan were 605 and 7,710 U/mg, respectively. Kinetic data showed that the lower molecular weight Xyn-2 had a higher affinity (K m?=?3.2?±?0.2 g/l) towards birchwood xylan than Xyn-1 by about 4-fold. The melting temperature (T m) of the two proteins, estimated to be in the range of 49.5–53.7 °C indicated that they are rather thermostable proteins. N-terminal and internal peptide sequences were obtained by chemical digestion of the purified xylanases to facilitate cloning, expression in Escherichia coli, and sequencing of the respective gene. The cloned Rhizopus xylanases were used to demonstrate release of xylose from flax shives-derived hemicellulose as model feedstock. Overall, this study expands the catalytic toolbox of GH10 and 11 family proteins that have applications in various industrial and bioproducts settings.  相似文献   

13.
Glucose isomerase (GIase) catalyzes the isomerization of d-glucose to d-fructose. The GIase from Thermobifida fusca WSH03-11 was expressed in Escherichia coli BL21(DE3), and the purified enzyme took the form of a tetramer in solution and displayed a pI value of 5.05. The temperature optimum of GIase was 80 °C and its half life was about 2 h at 80 °C or 15 h at 70 °C. The pH optimum of GIase was 10 and the enzyme retained 95 % activity over the pH range of 5–10 after incubating at 4 °C for 24 h. Kinetic studies showed that the K m and K cat values of the enzyme are 197 mM and 1,688 min?1, respectively. The maximum conversion yield of glucose (45 %, w/v) to fructose of the enzyme was 53 % at pH 7.5 and 70 °C. The present study provides the basis for the industrial application of recombinant T. fusca GIase in the production of high fructose syrup.  相似文献   

14.
We previously reported on a new yeast strain of Clavispora sp. NRRL Y-50464 that is capable of utilizing cellobiose as sole source of carbon and energy by producing sufficient native β-glucosidase enzyme activity without further enzyme supplementation for cellulosic ethanol production using simultaneous saccharification and fermentation. Eliminating the addition of external β-glucosidase reduces the cost of cellulosic ethanol production. In this study, we present results on the isolation and identification of a β-glucosidase protein from strain Y-50464. Using Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and blast search of the NCBInr database (National Center for Biotechnology Information nonredundant), the protein from Y-50464 was identified as a β-glucosidase (BGL1) with a molecular weight of 93.3 kDa. The BGL1 protein was purified through multiple chromatographic steps to a 26-fold purity (K m?=?0.355 mM [pNPG]; K i?=?15.2 mM [glucose]), which has a specific activity of 18.4 U/mg of protein with an optimal performance temperature at 45 °C and pH of 6.0. This protein appears to be intracellular although other forms of the enzyme may exist. The fast growth rate of Y-50464 and its capability to produce sufficient β-glucosidase activity for ethanol conversion from cellobiose provide a promising means for low-cost cellulosic ethanol production through a consolidated bioprocessing development.  相似文献   

15.
A novel Gram-negative, orange pigmented, strictly aerobic bacterium, designated strain IP9T, was isolated from seawater at the sea shore of Incheon Eulwang-ri beach, South Korea. Cells of strain IP9T were observed to be straight or slightly curved rods and colonies to be round and convex. Strain IP9T was found to be catalase and oxidase positive, and non-motile. Growth was observed in the temperature range of 10–37 °C (optimum at 30 °C), pH range of 6–10 (optimum at pH 7–8) and salt concentration range of 0–7% (w/v) NaCl (optimum at 0–1%). On the basis of 16S rRNA gene sequence similarity and phylogenetic analysis, strain IP9T was found to be related to the members of the family Flavobacteriaceae, being closely related to Hwangdonia seohaensis KCTC 32177T (95.3% sequence similarity). The DNA G?+?C content of the novel strain was determined to be 39.1 mol%. The major polar lipids were found to be phosphatidylethanolamine, three unidentified aminoglycolipids and two unidentified glycolipids. The major fatty acids (>?10%) were identified as iso-C15:0 and iso-C17:0 3-OH. The predominant quinone was found to be menaquinone 6 (MK-6). Based on the biochemical, phylogenetic and physiological data, we conclude that strain IP9T (=?KCTC 52523T?=?JCM 31732T) represents the type species of a novel genus of the family Flavobacteriaceae for which the name Thalassorhabdus aurantiaca gen. nov., sp. nov. is proposed.  相似文献   

16.
A gram-positive bacterium Citricoccus nitrophenolicus (strain PNP1T, DSM 23311T, CCUG 59571T) isolated from a waste water treatment plant was capable of effectively degrading p-nitrophenol (pNP) as a source of carbon, nitrogen and energy for growth. Degradation of pNP required oxygen and resulted in the stoichiometric release of nitrite. Strain PNP1T also degraded 4-chlorophenol, phenol and salicylate. pNP was degraded at pH values between 6.8 and 10.0 and at temperatures between 15–32 °C. pNP at concentrations up to 150 mg L?1 were degraded during growth in media at pH ≤ 10, whereas 200 mg L?1 was completely inhibitory to growth. When incubated in an NH4Cl-free medium (pH 10) containing both pNP and acetate, pNP is degraded with concomitant release of nitrite which was subsequently assimilated during acetate degradation. Intact cells of strain PNP1T suspended in NaHCO3/Na2CO3 buffer were able to continuously degrade 200 mg L?1 pNP over a 40 day period at pH 10.  相似文献   

17.
Strain SR-1T, a Gram-positive, strictly-aerobic, short-rod shaped, non-motile bacterium, was isolated from a mountain soil collected in Seoul Women’s University in South Korea. Growth occurred between 15 and 37 °C (optimum, 30 °C), at pH 6.0–9.0 (optimum, pH 7.0) and with 0–2 % NaCl. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain SR-1T belongs to the genus Nocardioides and is closely related to Nocardioides simplex KCTC 9106T (96.8 %), Nocardioides caeni MN8T (96.7 %), Nocardioides aromaticivorans H-1T (96.6 %), and Nocardioides kongijuensis A2-4T (96.6 %). Chemotaxonomic data revealed that strain SR-1T possesses MK-8(H4) as predominant menaquinone, ll-2,6-diaminopimelic acid as the diagnostic diamino acid, phosphatidylglycerol and diphosphatidylglycerol as predominant polar lipids and iso-C16:0, 10-methyl-C18:0, and C18:1 ω9c are major fatty acids. The DNA G+C content of the strain SR-1T was 72.4 mol%. Based on polyphasic evidence, strain SR-1T (= KEMC 9004-134T = JCM 19684T) should be classified as the type strain of a novel Nocardioides species, for which the name Nocardioides soli sp. nov. is proposed.  相似文献   

18.
A Gram-stain negative, ovoid-rod shaped, strictly aerobic bacterium, strain Y2T, was isolated from a deep-sea sediment of the Western Pacific. Phylogenetic and phenotypic properties of the organism indicated that it belongs to the genus Altererythrobacter. Strain Y2T shares highest 16S rRNA gene sequence similarity of 96.6 % with Erythrobacter jejuensis CNU001T, followed by the type strains of recognized members of the genus Altererythrobacter (94.8–96.5 %). Strain Y2T forms a clade with E. jejuensis CNU001T in the cluster of species of the genus Altererythrobacter. Growth of strain Y2T was observed at 4–40 °C (optimum, 35–37 °C), at pH 6.0–10.0 (optimum, pH 7.0–8.0) and in the presence of 0–5 % (w/v) NaCl (optimum, 2–3 %). The major cellular fatty acids were found to be C17:1 ω6c (41.5 %), summed feature 8 (C18:1 ω7c and/or C18:1 ω6c; 17.2 %), C17:1 ω8c (11.0 %) and C15:0 2OH (8.1 %). The major respiratory quinone was determine to be ubiquinone 10 (Q-10). The polar lipid analysis indicated the presence of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, phosphatidylglycerol, one sphingoglycolipid, three unidentified phospholipids, two unidentified glycolipids, two unidentified aminolipids and three unknown lipids. The DNA G + C content of the type strain is 60.0 mol %. On the basis of the data from the polyphasic characterization, strain Y2T represents a novel species, for which the name Altererythrobacter oceanensis sp. nov. is proposed. The type strain is Y2T (=CGMCC 1.12752T =LMG 28109T).  相似文献   

19.
An aerobic, Gram-negative, moderately halophilic bacterium, oxidase, and catalase positive-designated Abdou3T, was isolated from salted traditional foods (Anchovies) in Tunisia. Cells were rod-shaped, non-spore-forming and motile. Growth occurred at 15–45 °C (optimum, 37 °C), pH 5.5–8.75 (optimum, 7.3), and in the presence of 1–15 % NaCl (optimum, 10 %). Strain Abdou3T used glucose, d-arabinose, and sucrose. Strain Abdou3T had Q9 as the major respiratory quinone and C18:1 ω9c and C16:0 as predominant fatty acids. The DNA G+C content was 55.2 mol%. Phylogenetic analysis of the small-subunit ribosomal RNA (rRNA) gene sequence indicated that strain Abdou3T had as its closest relative Marinobacter maritimus (identity of 96 %). Based on phenotypic, phylogenetic, and taxonomic characteristics, strain Abdou3T is proposed as a novel species of the genus Marinobacter within the order Alteromonadales, for which the name M. piscensis sp. nov. is proposed. The type strain is Abdou3T (=DSM 26804T).  相似文献   

20.
A Gram-staining negative, strictly aerobic, motile by gliding, non-spore-forming, pale yellow pigmented and rod-shaped bacterium designated strain THG-107T was isolated from soil of a ginseng field on Ganghwa Island in the Republic of Korea and its taxonomic position was investigated by using a polyphasic study. Growth of strain THG-107T was found to occur at 4–37 °C (optimum, 20–30 °C), at pH 5.5–10 (optimum, pH 7.0) and in the presence of 0–1 % (w/v) NaCl (optimum, absence) on R2A agar. On the basis of 16S rRNA gene sequence similarity, strain THG-107T was shown to belong to the family Flavobacteriaceae and was related to Flavobacterium denitrificans ED5T (99.1 % similarity). The G+C content of the genomic DNA was determined to be 34.2 mol%. These results are consistent with characteristics of members of the genus Flavobacterium. The only isoprenoid quinone detected in strain THG-107T was menaquinone-6 (MK-6) and the major polyamine was identified as homospermidine (82.9 %). The major polar lipid detected was phosphatidylethanolamine and the major cellular fatty acids were identified as iso-C15:0 (26.3 %), iso-C17:0 3OH (12.6 %) and summed feature 3 (comprising C16:1 ω7c and/or C16:1 ω6c; 11.6 %). Flexirubin-type pigments were found to be present. Strain THG-107T has β-glucosidase activity to convert ginsenosides Rb1 and Rd into Gyp17 and F2. DNA-DNA hybridization with F. denitrificans ED5T was 52 %. Strain THG-107T could be distinguished from F. denitrificans ED5T and the other species of the genus Flavobacterium by its phylogenetic and genetic distinctiveness and by several phenotypic properties. Therefore, strain THG-107T is considered to represent a novel species in the genus Flavobacterium, for which the name Flavobacterium kyungheensis sp. nov. is proposed (type strain THG-107T = KACC 16219T = LMG 26575T).  相似文献   

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