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1.
Two isolates of methanethiol producing coryneform bacteria sharing morphological and physiological similarities with Brevibacterium are described. They were isolated from bumble-foot-like manifestations of poultry but proved to be non-pathogenic for experimental animals.  相似文献   

2.
The activity ofNocardia V. nitro-reductase appears to vary considerably during the life cycle of the culture. The optimal conditions found for the formation of the highest amount of enzyme per unit dry weight of cell were: incubation of the organism in a medium containing salts, glucose, and sodium glutamate at pH 7.4 for 28–30 hr at about 29–30 C. TheNocardia nitro-reductase is a constitutive enzyme in contrast to the adaptive nitrate- and nitrite-reductases in other organisms. The enzyme requires a sulphydryl compound for activity and uses reduced pyridine nucleotides as the electron donor for the reduction of nitro-groups. The only reduction product found when usingp-dinitrobenzene as substrate of the nitro-reductase isp-nitroaniline. This compound has been identified by electrophoresis, spectroscopy, melting point, chemical derivatives and elementary analysis. No evidence has been obtained which indicates the nature of the intermediate steps in the biological reduction of nitro-groups.  相似文献   

3.
Li J  Long LJ  Yang LL  Xu Y  Wang FZ  Li QX  Zhang S  Li WJ 《Antonie van Leeuwenhoek》2012,102(1):157-162
A novel actinobacterium, designated strain SCSIO 10480T, was isolated from a gorgonian coral sample of Anthogorgia sp. Phylogenetic and phenotypic properties of the organism supported that it belonged to the genus Janibacter. Phylogenetic analysis indicated that the levels of 16S rRNA gene sequence similarity between strain SCSIO 10480T and other type strains of recognized members of the genus Janibacter were 96.0–97.8 %. Growth in the presence of up to 17 % (w/v) NaCl and optimally at pH 9.0–10.0 was a distinctive characteristic of strain SCSIO 10480T. Other biochemical and physiological properties and the fatty acid profile also differentiated the isolate from other members of Janibacter species. Based on the results obtained in this study, we propose that strain SCSIO 10480T should be classified within a novel species of the genus Janibacter, for which the name Janibacter alkaliphilus sp. nov. is proposed, with SCSIO 10480T (=CCTCC AB 2011027T = DSM 24723T) as the type strain.  相似文献   

4.
苜蓿、草木樨、锦鸡儿根瘤菌的表型多样性分析   总被引:23,自引:1,他引:22  
选用48株分离自新疆和内蒙的苜蓿属、草木樨属、锦鸡儿属植物的根瘤菌菌株, 进行了营养利用、抗生素抗性、耐逆性和酶活性测定等133个表型性状分析。发现分离自同种寄主植物的根瘤菌由于地理来源的不同而存在着较大的多样性。通过数值分类,各已知种分别聚群,41株未知菌在85%的相似水平上分为3个不同于已知种的群。群1的菌株主要分自苜蓿,群2的菌株主要分自草木樨,群3的菌株分自锦鸡儿,XJ96 333(寄主为Melilotus)作为1个单株在84%的相似水平上和群1聚在一起。NM 020(寄主为Caragana)在88%的相似水平上和R.leguminosarum聚在一起; NM 183、NM 218(寄主为Caragana)在86%的相似水平上和S.fredii聚在一起; 在67%的相似水平上, XJ96 482(寄主为Medicago sativa)和其它所有供试菌株聚群。群1、2、3的所有菌株能在含2.0%(340 mM)NaCl的YMA培养基上、pH 9.0的YMA培养基、40℃的高温下生长; 群3的所有菌株还能在含3.0%(510 mM)NaCl的YMA培养基上生长;群1中90%的菌株和群2、3的所有菌株能在10℃的低温下生长。 表明群1、2、3的菌株具有较强的耐盐碱、耐高低温的特性。和已知种S.meliloti具有相同寄主的群1、群2在85%相似水平上未和S.meliloti聚群,表现了这两群菌在表型上的多样性。  相似文献   

5.
Summary Nebularine has now been isolated from a novelMicrobispora sp., identified as a new mesophilic species. An efficient method for the isolation of nebularine using Droplet Counter Current Chromatography is described.  相似文献   

6.
Exocellular chitinase from a Streptomyces sp   总被引:13,自引:0,他引:13  
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7.
8.
Acinetobacter strain IVS-B aerobically grows on isovalerate as sole carbon and energy source. Isovalerate is metabolised via isovaleryl-CoA, an intermediate of the oxidative (S)-leucine degradation pathway. A 3-methylglutaconyl-CoA hydratase (EC 4.2.1.18) was purified 65-fold to apparent homogeneity from cell-free extracts of isovalerate-grown cells of Acinetobacter strain IVS-B. The enzyme was found to be a homotetramer (115.2 kDa) composed of four identical subunits of 28.8 kDa not containing any cofactors. The enzyme was shown to catalyse the hydration of (E)-glutaconyl-CoA (k cat=18 s−1, K m=40 μM) and the dehydration of (S)-3-hydroxyglutaryl-CoA (k cat=13 s−1, K m=52 μM), albeit with somewhat lower catalytic efficiencies as compared to the 3-methyl derivatives, 3-methylglutaconyl-CoA (k cat=138 s−1, K m=14 μM) and (S)-3-hydroxy-3-methylglutaryl-CoA (k cat=60 s−1, K m=36 μM). Thus, the mechanistically simple syn-addition of water to the (E)-isomer of 3-methylglutaconyl-CoA of the leucine degradative pathway leading to the common intermediate (S)-3-hydroxy-3-methylglutaryl-CoA was assigned as the major physiological role to this enzyme. The amino acid sequence of 3-methylglutaconyl-CoA hydratase from Acinetobacter sp. was found to be related to over 100 prokaryotic enoyl-CoA hydratases (up to 50% identity), possibly all being 3-methylglutaconyl-CoA hydratases.An erratum to this article can be found at  相似文献   

9.
10.
A total of 21 bacterial cultures were isolated that could utilize glyphosate (N-phosphonomethyl glycine) as a sole source of phosphorus in a mineral salts medium. Sources of inocula for enrichment cultures included aerobic digester liquid, raw sewage, trickling filter effluent, pesticide disposal pit liquid, and soil. Eleven cultures were identified asPseudomonas sp., one asPseudomonas stutzeri, and nine asAlcaligenes sp. Aminomethylphosphonic acid, the major metabolic intermediate of glyphosate degradation in soil, could also serve as a sole phosphorus source for all 21 isolates. Neither glyphosate nor aminomethylphosphonic acid could serve as carbon sources in mineral salts media. Experiments withPseudomonas sp. SG-1 (isolated from aerobic digester liquid) suggested that enzymatic activity responsible for glyphosate degradation was intracellular, inducible, and required the cofactors pyruvate and pyridoxal phosphate. The degradation pathway for glyphosate in this culture may be similar to that previously reported for aminoethylphosphonic acid.  相似文献   

11.
B.R. MOHAPATRA, R.K. SANI AND U.C. BANERJEE. 1995. The bacterial flora associated with an intertidal marine alga ( Sargassum sp.) were screened for the presence of extracellular L-asparaginase; one out of five Bacillus strains was found positive. The maximum L-asparaginase activity was found at 37°C and pH 8.0. The optimum NaCl concentration for enzyme activity was found to be 2% (w/v). The enzyme activity was not affected by the addition of different metal ions (Ca2+, Co2+, Fe2+, Mg2+and Ni2+) at 10 mmol 1-1, but was strongly inhibited by EDTA.  相似文献   

12.
13.
Two new spliceostatin analogs, designed as spliceostatins J and K ( 1 and 2 ), were isolated and identified from the culture of Pseudomonas sp., along with two known ones, FR901464 ( 3 ) and spliceostatin E ( 4 ). Their structures were elucidated by detailed interpretation of their spectroscopic data, especially 2D‐NMR and HR‐ESI‐MS. Spliceostatin J ( 1 ) represented the first example of spliceostatins bearing an unusual hexahydrofuro[3,4‐b]furan moiety. Biological assay showed all the isolated compounds except 1 displayed potent cytotoxic activities against two cancer cell lines (MDA‐MB‐231 and A‐549). Structure‐activity‐relationship studies revealed that the tetrahydropyran ring in spliceostatin analogs was necessary for their bioactive retention.  相似文献   

14.
Protease was isolated from Sporosarcina RRLJ1 which was collected from acid tea (Camellia sinensis) plantations. It showed potential for production of the enzyme for commercial purposes. The study revealed that optimum pH for growth of the organism was 6.5-7 and supplement of casein (1%) in the medium was required for production of protease. Enzyme production and enzyme activity was maximum in 72 hr old broth culture. Maximum activity of the enzyme was found at pH 6.5.  相似文献   

15.
Two new brominated compounds, subereaphenol K ( 2 ) and 2‐(3,5‐dibromo‐1‐ethoxy‐4‐oxocyclohexa‐2,5‐dien‐1‐yl)acetamide ( 3 ), together with subereaphenol B (methyl 2‐(2,4‐dibromo‐3,6‐dihydroxyphenyl)acetate; 1 ) with a revised structure, and five dibromotyrosine‐derived metabolites, 4 – 8 , were isolated from the sponge Suberea sp. and characterized by 1D‐ and 2D‐NMR spectroscopic and HR‐MS spectrometric data. Compounds 1, 2, 6 , and 8 exhibited various weak or moderate bioactivities, including antimicrobial and cytotoxic activities. Furthermore, compounds 1 and 2 inhibited human recombinant phosphodiesterase 4 (PDE4) with IC50 values of 2 μM , whereas compounds 6 and 8 were less active.  相似文献   

16.
Total ceramides containing nonbranched and iso-branched C18- and C19-phytosphingosines acylated with non-hydroxylated fatty acids were isolated from a marine sponge Oceanapia sp. The structures of these compounds were determined by HPLC, NMR, MALDI-TOF MS, and GLC-MS of the Me3Si derivatives and by chemical transformations. The English version of the paper: Russian Journal of Bioorganic Chemistry, 2006, vol. 32, no. 3; see also http://www.maik.ru.  相似文献   

17.
18.
Gamma-butyrobetaine hydroxylase from Pseudomonas sp AK 1   总被引:1,自引:0,他引:1  
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19.
Li G  Deng Z  Guan H  van Ofwegen L  Proksch P  Lin W 《Steroids》2005,70(1):13-18
Fifteen steroids were isolated from the soft coral Dendronephthya sp., of which five are determined as new compounds, namely (22E)-3-O-beta-formylcholest-5,22-diene (1), (22E)-3-O-beta-formyl-24-methyl-cholest-5,22-diene (2), 2-ethoxycarbonyl-2-beta-hydroxy-A-nor-cholest-5-ene-4-one (3), (22E)-2-ethoxycarbonyl-2-beta-hydroxy-A-nor-cholest-5,22-diene-4-one (4), and (22E)-2-ethoxycarbonyl-2-beta-hydroxy-24-mthyl-A-nor-cholest-5,22-diene-4- one (5). 1 and 2 belonged to 3-O-formylated cholesterol analogues, and 3 to 5 are unique ring A-contracted steroids. Their structures were elucidated by extensive 2D NMR in association with IR, MS analysis.  相似文献   

20.
The surface are and crystallinity was measured on a cellulose powder made from Cladophora sp. algae. The algae cellulose powder was found to have a very high surface area (63.4 m2/g, N2 gas adsorption) and build up of cellulose with a high crystallinity (approximately 100%, solid state NMR). The high surface area was confirmed by calculations from atomic force microscope imaging of microfibrils from Cladophora sp. algae.  相似文献   

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