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1.
2.
AcetylCoA carboxylase (E.C.6.4.1.2) enzymatic activity was studied in high- and low-producing strains ofStreptomyces aureofaciens. Study of the rate of H14CO3 ? incorporation into acetylCoA and of CH3 14COO? incorporation into the fatty acids showed that specific activity attained maximum values after about 24 hours' cultivation. AcetylCoA carboxylase activity in the producing strain was approximately double the value in the low-producing strain. The subcellular particles present in the supernatant fractions from cells disintegrated by spinning one hour at 600g and 10,000g did not influence the activity of the enzyme. Avidin inhibited it. The relationship between specific activity of the enzyme and the rate of oligoketide synthesis is discussed.  相似文献   

3.
A novel thermophilic, Gram-staining positive bacterium, designated DX-2T, was isolated from the anode biofilm of a microbial fuel cell. Cells of the strain were oxidase positive, catalase positive, facultative anaerobic, motile rods. The isolate grew at 30–60 °C (optimum 50 °C) and pH 5–9 (optimum pH 8–8.5). The pairwise 16S rRNA gene sequence similarities showed that strain DX-2T was most closely related to Bacillus fumarioli LMG 17489T (96.2 %), B. firmus JCM 2512T (96.0 %) and B. foraminis DSM 19613T (95.7 %). Phylogenetic analysis based on 16S rRNA gene sequences showed that strain DX-2T formed a cluster with B. smithii (95.5 %) and B. infernus (94.9 %). The genomic G+C content of DX-2T was 43.7 mol%. The predominant respiratory quinone was MK-7. The polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and unknown phospholipids. The major cellular fatty acid was iso-C16:0. Based on its phenotypic characteristics, chemotaxonomic features, and results of phylogenetic analysis, the strain was identified to represent a distinct novel species in the genus Bacillus, and the name proposed is B. thermophilum sp. nov. The type strain is DX-2T (=CCTCC AB2012194T = KCTC 33128T).  相似文献   

4.
The laboratory strains of Chlamydomonas reinhardtii have been reported to contain no phosphatidylcholine (PC), which is considered to be replaced by another zwitterionic lipid, diacylglyceryl-N,N,N-trimethylhomoserine (DGTS). According to the recently published classification, the strains belonged to the subgroup Reinhardtinia. Screening for PC in 13 selected strains of Chlamydomonas in the NIES Algal Collection, which are different in habitats and belong to different phylogenetic subgroups in the genus, revealed the presence of PC in four strains: a strain in the subgroup Polytominia, and three strains in Reinhardtinia. PC was not detected in three other strains of Reinhardtinia analyzed. The presence/absence of PC was not related to the phylogenetic relationship based on 18S rRNA. DGTS was detected in all the strains analyzed. The rare isomer of linolenic acid, 18:3(5,9,12), which has been found in the DGTS of C. reinhardtii, was found in the PC of the two strains and in the DGTS of the five strains. The occurrence of this fatty acid seems limited to a branch of Reinhardtinia. Acquisition and loss of PC in various strains of Chlamydomonas are discussed from the viewpoint of evolution of PC biosynthetic pathway.  相似文献   

5.
An aerobic, Gram-staining negative, non-motile, and rod-shaped bacterial strain, SS011A0-7#2-2T, was isolated from the sediment of South China Sea with the depth of 1,500 m. Optimum growth occurred at pH 8.0, 30 °C, and 6 % (w/v) NaCl. Strain SS011A0-7#2-2T did not synthesize bacteriochlorophyll a or carotenoid, neither possess photosynthesis genes. Its genome DNA G+C content was 67.9 mol%. It contained Q-10 as the predominant ubiquinone and C18:1 ω7c (52.3 %) as the major fatty acid. The major polar lipids were phosphatidylcholine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, unidentified phospholipid, and unidentified aminolipid. The 16S rRNA gene sequence analysis revealed that it was closely related to Seohaeicola saemankumensis SD-15T, Phaeobacter gallaeciensis BS 107T and Roseovarius pacificus 81-2T in Rhodobacteraceae, with the 16S rRNA gene sequence similarities being 96.5, 95.7, and 95.6 %, respectively. However, the phylogeny of the 16S rRNA gene sequences revealed that strain SS011A0-7#2-2T was a member of the genus Seohaeicola. Strain SS011A0-7#2-2T was moderately halophilic which was different from Seohaeicola saemankumensis SD-15T, and it showed the enzyme activities and carbon source spectrum significantly different from Seohaeicola saemankumensis SD-15T. As its physiological and chemotaxinomic properties were different from those of Seohaeicola saemankumensis SD-15T, strain SS011A0-7#2-2T represents a novel species of the genus Seohaecola. The name Seohaeicola nanhaiensis sp. nov. is proposed, with strain SS011A0-7#2-2T (=LMG 27733T = CGMCC 1.12759T) as the type strain.  相似文献   

6.
A Gram-stain-negative, aerobic, non-motile and rod-shaped or ovoid bacterial strain, GJSW-22T, which was isolated from seawater at Geoje island in South Korea, was characterized taxonomically. Strain GJSW-22T was observed to grow optimally at 30 °C, at pH 7.0–8.0 and in the presence of 2.0 % (w/v) NaCl. In the neighbour-joining phylogenetic tree based on 16S rRNA gene sequences, strain GJSW-22T grouped with the type strains of Thalassobius species, forming a stable cluster with the type strain of Thalassobius aestuarii (bootstrap value of 83.2 %). Strain GJSW-22T exhibited the highest 16S rRNA gene sequence similarity value (98.0 %) to the type strain of T. aestuarii. It exhibited 16S rRNA gene sequence similarity values of 95.6–96.1 % to the type strains of the other Thalassobius species. Strain GJSW-22T was found to contain Q-10 as the predominant ubiquinone and C18:1 ω7c and 11-methyl C18:1 ω7c as the major fatty acids. The major polar lipids of strain GJSW-22T were identified as phosphatidylcholine, phosphatidylglycerol, phosphatidylethanolamine, one unidentified aminolipid and one unidentified lipid. The DNA G + C content of strain GJSW-22T is 60.3 mol % and its mean DNA–DNA relatedness value with the type strain of T. aestuarii was 23 %. Differential phenotypic properties, together with the phylogenetic and chemotaxonomic data, confirmed that strain GJSW-22T is distinct from other Thalassobius species. On the basis of the data presented, strain GJSW-22T is considered to represent a novel species of the genus Thalassobius, for which the name Thalassobius aquaeponti sp. nov. is proposed. The type strain is GJSW-22T (=KCTC 42115T = NBRC 110378T).  相似文献   

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8.
Ralstonia paucula strain RA4T, a gram negative, non-spore forming, motile bacterium having positive catalase and oxidase test, was isolated from surface soil. Twin arginine translocation protein type D (TatD) is shown to be located in cytoplasm and exhibits magnesium-dependent DNase. A tatD DNase gene was isolated and cloned from Ralstonia paucula RA4T genome. Nucleotide sequence analysis of the gene revealed 813 nucleotides encoding a protein of 270 amino acid residues. The tatD gene showed a high similarity to homolog gene from Ralstonia pickettii strain 12D. The deduced polypeptide sequence of TatD DNase from R. paucula RA4T had a typical catalytic site, HHPLDEHRHDP, and its calculated molecular mass and predicted isoelectric point were 29616 Da and 5.33, respectively. The deduced amino acid sequence showed a high degree of similarity to TatD DNase isoforms from Ralstonia genus and other sources. Predicted three-dimensional structure of TatD confirmed the presence of active site and theoretical function as DNase.  相似文献   

9.
Candida infections are frequently reported in both HIV and cancer patients. Recent reports have shown that Candida participates in malignant transformation of oral fibrosis. The aim of the present study was to isolate and to identify anticandidal compound from soil Streptomyces sp. VITPK9. It was isolated from a brine spring of Manipur located in Thoubal district, Manipur, India. The ethyl acetate extract from culture supernatant of Streptomyces sp. VITPK9 was prepared and purified by silica gel column chromatography and HPLC. The purified compound was identified by using 1H and 13C NMR spectral data and based on the similarity index with reference compounds available in the mass spectra library of National Institute for Standards and Technology as pyrrolo[1,2-a]pyrazine-1,4-dione,hexahydro-3-(phenylmethyl)-. The antifungal activity of the purified compound was tested against the Candida strains according to the National Committee for Clinical Laboratory Standards guidelines and it was revealed that its MIC50 value ranged from 0.78 to 2.00 μg/mL. The results of the study suggest that Streptomyces sp. VITPK9 is the potential source for diketopiperazine type of anticandidal compounds.  相似文献   

10.
A Gram-stain negative, short rod-shaped aerobic bacterium with flagella, designated strain Y32T, was isolated from coastal seawater in Xiamen, Fujian Province of China. 16S rRNA gene sequence comparisons showed that strain Y32T is a member of the family Oceanospirillaceae, forming a distinct lineage with species of the genus Litoribacillus. The 16S rRNA gene sequence similarities between strain Y32T and other strains were all less than 94.0 %. Strain Y32T was found to grow optimally at 28 °C, at pH 7.0–8.0 and in the presence of 4–5 % (w/v) NaCl. The major fatty acids were identified as Summed Feature 3 (comprising C16:1 ω7c and/or C16:1 ω6c, 49.4 %), C16:0 (17.7 %), C14:0 (6.9 %) and C18:1 ω9c (5.4 %). The major respiratory quinone was identified as ubiquinone-8 (Q-8). The major polar lipids were identified as diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylglycerol. The DNA G+C content of strain Y32T was determined to be 55.6 mol%. According to its morphology, physiology, fatty acid composition, polar lipids composition and 16S rRNA gene sequence data, strain Y32T represents a novel species of a new genus in the family Oceanospirillaceae, for which the name Litoribrevibacter albus gen. nov. sp. nov. is proposed. The type strain of Litoribrevibacter albus is Y32T (=MCCC 1F01211T=NBRC 110071T).  相似文献   

11.
Propolis presents many biological properties, including antibacterial activities, and has been proposed as an additive in ruminant nutrition. Twenty bacterial strains, previously isolated from enrichments of Brazilian cow rumen contents in the presence of different propolis extracts (LLOS), were characterized using phenotyping and 16S rRNA identification. Seven strains were assigned to Streptococcus sp., most likely S. bovis, and were all degrading starch. One amylolytic lactate-utilizing strain of Selenomonas ruminantium was also found. Two strains of Clostridium bifermentans were identified and showed proteolytic activity. Two strains were assigned to Mitsuokella jalaludinii and were saccharolytic. One strain belonged to a Bacillus species and seven strains were affiliated with Escherichia coli. All of the 20 strains were able to use many sugars, but none of them were able to degrade the polysaccharides carboxymethylcellulose and xylans. The effect of three propolis extracts (LLOS B1, C1 and C3) was tested on the in vitro growth of four representative isolates of S. bovis, E. coli, M. jalaludinii and C. bifermentans. The growth of S. bovis, E. coli and M. jalaludinii was not affected by the three propolis extracts at 1 mg ml?1. C. bifermentans growth was completely inhibited at this LLOS concentration, but this bacterium was partially resistant at lower concentrations. LLOS C3, with the lower concentration of phenolic compounds, was a little less inhibitory than B1 and C1 on this strain.  相似文献   

12.
A Gram-stain positive, facultative anaerobic endospore-forming bacterium, designated strain YIM h-19T, was isolated from a tobacco sample. Cells were observed to be motile rods by means of peritrichous flagella and colonies were observed to be convex, yellow, circular and showed catalase-positive and oxidase-negative reactions. Strain YIM h-19T was able to grow at 4–45 °C, pH 6.0–8.0 and 0–3 % NaCl (w/v). The predominant respiratory quinone was identified as MK-7. Major fatty acids were identified as anteiso-C15:0, anteiso-C17:0 and C16:0. The polar lipids were found to be phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol and two unidentified polar lipids. The genomic DNA G+C content was determined to be 54 mol%. 16S rRNA gene sequence analysis showed the strain YIM h-19T was most closely related to Paenibacillus hordei RH-N24T and Paenibacillus hunanensis FeL05T with similarities of 98.30 and 94.64 % respectively. However, DNA–DNA hybridization data indicated that the isolate represented a novel genomic species with the genus Paenibacillus. All data from genotypic and phenotypic analyses support the conclusion that strain YIM h-19T represents a novel species of the genus Paenibacillus, for which the name Paenibacillus nicotianae sp. nov. is proposed. The type strain is YIM h-19T (=CGMCC1.12819T = NRRL B-59112T).  相似文献   

13.
Ginsenosides are the major pharmacological components in ginseng. We isolated lactic acid bacteria from Kimchi to identify microbial modifications of ginsenosides. Phylogenetic analysis of 16S rRNA gene sequences indicated that the strain DCY65-1 belongs to the genus Lactobacillus and is most closely related to Lactobacillus brevis. On the basis of TLC and HPLC analysis, we found two metabolic pathways: F1 → 6α,12β-dihydroxydammar-3-one-20(S)-O-β-d-glucopyranoside and C–K → 12β-hydroxydammar-3-one-20(S)-O-β-d-glucopyranoside. These results suggest that strain DCY65-1 is capable of potent ketonic decarboxylation, ketonizing the hydroxyl group at C-3. The F1 metabolite had a more potent inhibitory effect on mushroom tyrosinase than did the substrate. Therefore, the F1 and C–K derivatives may be more pharmacologically active compounds, which should be further characterized.  相似文献   

14.
Occurrence of feruloyl-CoA synthetase (fcs) and enoyl-CoA hydratase (ech) genes responsible for the bioconversion of ferulic acid to vanillin have been reported and characterized from Amycolatopsis sp., Streptomyces sp., and Pseudomonas sp. Attempts have been made to express these genes in Escherichia coli DH5α, E. coli JM109, and Pseudomonas fluorescens. However, none of the lactic acid bacteria strain having GRAS status was previously proposed for heterologous expression of fcs and ech genes for production of vanillin through biotechnological process. Present study reports heterologous expression of vanillin synthetic gene cassette bearing fcs and ech genes in a dairy isolate Pediococcus acidilactici BD16. After metabolic engineering, statistical optimization of process parameters that influence ferulic acid to vanillin biotransformation in the recombinant strain was carried out using central composite design of response surface methodology. After scale-up of the process, 3.14 mM vanillin was recovered from 1.08 mM ferulic acid per milligram of recombinant cell biomass within 20 min of biotransformation. From LCMS-ESI spectral analysis, a metabolic pathway of phenolic biotransformations was predicted in the recombinant P. acidilactici BD16 (fcs +/ech +).  相似文献   

15.
Strain DCY84T, a Gram-stain positive, rod-shaped, aerobic, spore-forming bacterium, motile by means of peritrichous flagella, was isolated from humus soil from Yongin forest in Gyeonggi province, South Korea. Strain DCY84T shared the highest sequence similarity with Paenibacillus barengoltzii KACC 15270T (96.86 %), followed by Paenibacillus timonensis KACC 11491T (96.49 %) and Paenibacillus phoenicis NBRC 106274T (95.77 %). Strain DCY84T was found to able to grow best in TSA at temperature 30 °C, at pH 8 and at 0.5 % NaCl. MK-7 menaquinone was identified as the isoprenoid quinone. The major polar lipids were identified as phosphatidylethanolamine, an unidentified aminophospholipid, two unidentified aminolipids and an unidentified polar lipid. The peptidoglycan was found to contain the amino acids meso-diaminopimelic acid, alanine and d-glutamic acid. The major fatty acids of strain DCY84T were identified as branched chain anteiso-C15:0, saturated C16:0 and branched chain anteiso-C17:0. The cell wall sugars of strain DCY84T were found to comprise of ribose, galactose and xylose. The major polyamine was identified as spermidine. The DNA G+C content was determined to be 62.6 mol%. After 6 days of incubation, strain DCY84T produced 52.96 ± 1.85 and 72.83 ± 2.86 µg/ml l-indole-3-acetic acid, using media without l-tryptophan and supplemented with l-tryptophan, respectively. Strain DCY84T was also found to be able to solubilize phosphate and produce siderophores. On the basis of the phenotypic characteristics, genotypic analysis and chemotaxonomic characteristics, strain DCY84T is considered to represent a novel species of the genus Paenibacillus, for which the name Paenibacillus yonginensis sp. nov. is proposed. The type strain is DCY84T (=KCTC 33428T = JCM 19885T).  相似文献   

16.
A group of 29 isolates of Candida parapsilosis sensu stricto, 29 of Candida orthopsilosis, and 4 of Candida metapsilosis were assayed for the presence of killer activity using Saccharomyces cerevisiae ATCC 26609 as a sensitive strain. All C. metapsilosis isolates showed killer activity at 25 °C while strains of C. parapsilosis sensu stricto or C. orthopsilosis did not exhibit this activity. Sensitivity to killer toxins was evaluated using a set of previously reported killer strains of clinical origin. Only 11 isolates of the C. parapsilosis complex were inhibited by at least one killer isolate without resulting in any clear pattern, except for C. parapsilosis sensu stricto ATCC 22019, which was inhibited by every killer strain with the exception of C. parapsilosis and Candida utilis. The lack of sensitivity to killer activity among isolates of the genus Candida suggests that their toxins belong to the same killer type. Differentiation of species within the C. parapsilosis complex using the killer system may be feasible if a more taxonomically diverse panel of killer strains is employed.  相似文献   

17.
The experiments presented here were based on the conclusions of our previous results. In order to avoid introduction of expression plasmid and to balance the NADH/NAD ratio, the NADH biosynthetic enzyme, i.e., NAD-dependent glyceraldehyde-3-phosphate dehydrogenase (GADPH), was replaced by NADP-dependent GADPH, which was used to biosynthesize NADPH rather than NADH. The results indicated that the NADH/NAD ratio significantly decreased, and glucose consumption and l-lysine production drastically improved. Moreover, increasing the flux through l-lysine biosynthetic pathway and disruption of ilvN and hom, which involve in the branched amino acid and l-methionine biosynthesis, further improved l-lysine production by Corynebacterium glutamicum. Compared to the original strain C. glutamicum Lys5, the l-lysine production and glucose conversion efficiency (α) were enhanced to 81.0 ± 6.59 mM and 36.45 % by the resulting strain C. glutamicum Lys5-8 in shake flask. In addition, the by-products (i.e., l-threonine, l-methionine and l-valine) were significantly decreased as results of genetic modification in homoserine dehydrogenase (HSD) and acetohydroxyacid synthase (AHAS). In fed-batch fermentation, C. glutamicum Lys5-8 began to produce l-lysine at post-exponential growth phase and continuously increased over 36 h to a final titer of 896 ± 33.41 mM. The l-lysine productivity was 2.73 g l?1 h?1 and the α was 47.06 % after 48 h. However, the attenuation of MurE was not beneficial to increase the l-lysine production because of decreasing the cell growth. Based on the above-mentioned results, we get the following conclusions: cofactor NADPH, precursor, the flux through l-lysine biosynthetic pathway and DCW are beneficial to improve l-lysine production in C. glutamicum.  相似文献   

18.
Peaches with low acidity are preferred in the market and this trait is usually selected in commercial breeding programs. A major gene (D/d) has been described for this character located on linkage group 5 of peach, where the low acid character is determined by the dominant D allele. In this paper, we analyze a collection of 231 varieties and 542 offspring to identify diagnostic markers for this character. The CPPCT040 single sequence repeat (SSR) is known to be tightly linked to D. We found that one of its alleles (193) is diagnostic for the subacid character and identified with high probability individuals with low acidity (titratable acidity <5.5 mg/l). The region around CPPCT040 was explored using 13 DNA fragments for a total of 5,297 bp, covering a length of 70.4 kbp of the peach genome. The sequenced fragments detected 19 single nucleotide polymorphisms (SNPs) and five indels. All subacid individuals shared a large haplotype (>24 kb) around CPPCT040, a region with higher than average SNPs between acid and subacid varieties. The CPPCT040 marker plus one of the SNPs identified (DH875) were used to genotype a collection of 542 seedlings, from different crosses expected to segregate for this character, which were phenotyped by tasting the fruit in the field. Data provided by both markers were always consistent and only 24 plants (4 %) did not fit the expectations. These markers and others that can be obtained from the haplotype identified can be readily used for marker-assisted selection in peach breeding.  相似文献   

19.
A Gram-stain negative, yellow-pigmented, motile, pleomorphic bacterium, designated strain CBA4602T, was isolated from the gut of the sea cucumber Stichopus japonicus, which was collected from Jeju Island in the Republic of Korea. In a phylogenetic analysis based on the 16S rRNA gene, strain CBA4602T belonged to the order Sphingomonadales in the class Alphaproteobacteria. The 16S rRNA gene sequence similarity between strain CBA4602T and ‘Citromicrobium bathyomarinum’ JF-1, the most closely related strain having nonvalidly published name, was 98.4%, followed by 95.2–96.7% identities with sequence of the other closest strains in the genus Erythrobacter. Strain CBA4602T had bacteriochlorophyll a and carotenoids. Strain CBA4602T grew in 0–10% (w/v) NaCl, at 10–42°C and pH 6.0–8.0, with optimal growth in 1–2% NaCl, at 30–37°C and pH 7.0. Strain CBA4602T was positive for catalase and oxidase activities and was able to hydrolyse gelatine and Tween 20 and 40, but not starch, Tween 80 or l-tyrosine. The G+C content of genomic DNA from strain CBA4602T was 68.0 mol% and Q-10 was the major detected isoprenoid quinone. The polar lipids were three unidentified phospholipids, three unidentified glycolipids, and two unidentified lipids. The dominant fatty acids were anteiso-C15:0, C16:0, anteiso-C17:0 and C18:0. As considering the current taxonomic status of the genus ‘Citromicrobium’ and polyphasic taxonomic analyses, strain CBA4602T represents a novel genus and species. The name Citrimicrobium luteum is proposed for the type strain CBA4602T (=KACC 17668T =JCM 19530T).  相似文献   

20.
A Gram-negative, poly-3-hydroxybutyrate-accumulating rod bacterium, strain GYP-2T, was isolated from a pool of marine Spirulina platensis cultivation, Sanya, China. Growth was observed at 10–45 °C and pH 6–10 in the presence of 1–10 % (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the new isolate belonged to Gammaproteobacteria and displayed 93.8–95.3 % 16S rRNA gene sequences similarities to members of the genera Thalassolituus, Oleibacter, and Oceanobacter, but house-keeping gene gyrB (encode DNA gyrase beta subunit) demonstrated that the new isolate was distantly related to Thalassolituus, Oleibacter, and Oceanobacter species (only 77–83 % gene gyrB sequences similarities).The G+C content of genomic DNA was 55 mol%. The major respiratory quinone was Q-9, while that for Oceanobacter kriegii LMG 6238T was Q-8. Major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, and phosphatidylethanolamine. On the basis of its physiological, chemotaxonomic, and molecular properties, strain GYP-2T is suggested to represent a novel species of a new genus in Gammaproteobacteria, for which the name Bacterioplanes sanyensis gen. nov., sp. nov. is proposed. The type strain is GYP-2T (=CGMCC 1.12392T=KCTC 32220T).  相似文献   

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