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1.
Data of draft genome sequencing of Streptomyces fradiae-АТСС19609-Olg4R strain, resistant to (33S)-33-deoxy-33-thiocyanatooligomycin A, are presented. Comparative analysis of the genomes of S. fradiae wild-type strain ATCC19609 and S. fradiae strain ATCC19609-Olg4R showed the single nucleotide substitution that led to A(600)T change in the conservative P-loop NTPase region of class IV helicase gene, which, probably, promoted the resistance of S. fradiae strain ATCC19609-Olg4R to (33S)-33-deoxy-33-thiocyanatooligomycin A.  相似文献   

2.
Ganoderma boninense, the main causal agent of oil palm (Elaeis guineensis) basal stem rot (BSR), severely reduces oil palm yields around the world. To reduce reliance on fungicide applications to control BSR, we are investigating the efficacy of alternative control methods, such as the application of biological control agents. In this study, we used four Streptomyces-like actinomycetes (isolates AGA43, AGA48, AGA347 and AGA506) that had been isolated from the oil palm rhizosphere and screened for antagonism towards G. boninense in a previous study. The aim of this study was to characterize these four isolates and then to assess their ability to suppress BSR in oil palm seedlings when applied individually to the soil in a vermiculite powder formulation. Analysis of partial 16S rRNA gene sequences (512 bp) revealed that the isolates exhibited a very high level of sequence similarity (>?98%) with GenBank reference sequences. Isolates AGA347 and AGA506 showed 99% similarity with Streptomyces hygroscopicus subsp. hygroscopicus and Streptomyces ahygroscopicus, respectively. Isolates AGA43 and AGA48 also belonged to the Streptomyces genus. The most effective formulation, AGA347, reduced BSR in seedlings by 73.1%. Formulations using the known antifungal producer Streptomyces noursei, AGA043, AGA048 or AGA506 reduced BSR by 47.4, 30.1, 54.8 and 44.1%, respectively. This glasshouse trial indicates that these Streptomyces spp. show promise as potential biological control agents against Ganoderma in oil palm. Further investigations are needed to determine the mechanism of antagonism and to increase the shelf life of Streptomyces formulations.  相似文献   

3.
The structures of cell wall anionic carbohydrate-containing polymers in Streptomyces melanosporofaciens VKM Ac-1864T and phylogenetically close organisms—S. hygroscopicus subsp. hygroscopicus VKM Ac-831T, S. violaceusniger VKM Ac-583T, S. endus VKM Ac-1331T, S. endus VKM Ac-129, and S. rutgersensis subsp. castelarensis VKM Ac-832T—have been comparatively studied by chemical and NMR spectroscopic methods. The natural polymer of a new, previously unknown structure, Kdn (3-deoxy-D-glycero-D-galacto-non-2-ulopyranosonic acid) with β-galactose residues at C-9, has been found in the cell walls of all the strains under study. The cell walls of all the studied organisms contain three teichoic acids (TA): a predominant TA (1,3-poly(glycerol phosphate) with N-acetylated α-glucosaminyl substitutes by C-2 of glycerol, and minor TAs, 1,3-and 2,3-poly(glycerol phosphate) polymers without substitution. Their chains have O-acetyl and O-lysyl groups. Microorganisms of the above-mentioned species differ in the number of α-glucosaminyl substitutes and in the degree of their acetylation in the predominant teichoic acid.  相似文献   

4.
Actinomycetes are well-known for producing numerous bioactive secondary metabolites. In this study, primary screening by antifungal activity assay found one actinomycete strain WA23-4-4 isolated from the intestinal tract of Periplaneta americana that exhibited broad spectrum antifungal activity. 16S rDNA gene analysis of strain WA23-4-4 revealed close similarity to Streptomyces nogalater (AB045886) with 86.6% sequence similarity. Strain WA23-4-4 was considered as a novel Streptomyces and the 16s rDNA sequence has been submitted to GenBank (accession no. KX291006). The maximum antifungal activity of WA23-4-4 was achieved when culture conditions were optimized to pH 8.0, with 12% inoculum concentration and 210 ml ISP2 medium, which remained stable between the 5th and the 9th day. 3-Acetyl benzoyl amide was isolated by ethyl acetate extraction of WA23-4-4 fermentation broth, and its molecular formula was determined as C9H9NO2 based on MS, IR, 1H, and 13C NMR analyses. The compound showed significant antifungal activity against Candida albicans ATCC 10231 (MIC: 31.25 μg/ml) and Aspergillus niger ATCC 16404 (MIC: 31.25 μg/ml). However, the compound had higher MIC values against Trichophyton rubrum ATCC 60836 (MIC: 500 μg/ml) and Aspergillus fumigatus ATCC 96918 (MIC: 1,000 μg/ml). SEM analysis showed damage to the cell membrane of Candida albicans ATCC 10231 and to the mycelium of Aspergillus niger ATCC 16404 after being treatment with 3-acetyl benzoyl amide. In conclusion, this is the first time that 3-acetyl benzoyl amide has been identified from an actinomycete and this compound exhibited antifungal activity against Candida albicans ATCC 10231 and Aspergillus niger ATCC 16404.  相似文献   

5.
The oleaginous bacterium, Rhodococcus jostii RHA1 has attracted considerable attention due to its capability to accumulate significant levels of triacylglycerol as renewable hydrocarbon. To enable the strain to utilize arabinose derived from lignocellulosic biomass, the metabolic pathway of L-arabinose utilization was introduced into R. jostii RHA1 by heterogenous expression of the operon, araBAD from Escherichia coli. The results showed that recombinant bearing araBAD could grow on L-arabinose as the sole carbon source, and additional expression of araFGH encoding the arabinose transporter from E. coli could improve the cell biomass yield from high contents of arabinose. We further increased the content of lipid produced from arabinose in the recombinants from 47.9 to 56.8 % of the cell dry weight (CDW) by overexpression of a gene, atf1 encoding a diglyceride acyltransferase from R. opacus PD630. This work demonstrated the feasibility of producing lipid from arabinose by genetic modification of the rhodococci strain.  相似文献   

6.
A novel actinomycete, designated strain NEAU-LA29T, was isolated from soil collected from Xianglu Mountain and subjected to a polyphasic taxonomic study. Based on a polyphasic taxonomic approach comprising chemotaxonomic, phylogenetic, morphological and physiological characterisation, the isolate has been affiliated to the genus Streptomyces. 16S rRNA gene sequence analysis showed that the isolate is closely related to Streptomyces vastus JCM4524T (98.8% identity) and Streptomyces cinereus DSM43033T (97.9%). However, multilocus sequence analysis based on five other house-keeping genes (atpD, gyrB, rpoB, recA and trpB) and low DNA–DNA relatedness values enabled the strain to be differentiated from these closely related species of the genus Streptomyces. Thus, strain NEAU-LA29T is concluded to represent a novel species of the genus Streptomyces, for which the name Streptomyces xiangluensis sp. nov. is proposed. The type strain is NEAU-LA29T (=?CGMCC 4.7466T?=?DSM 105786T).  相似文献   

7.
The present study was designed to characterize phenotypically and genotypically a Trueperella pyogenes strain isolated from a brain abscess of an adult roebuck (Capreolus capreolus). The species identity could be confirmed by phenotypical investigations, by MALDI-TOF MS analysis, and by sequencing the 16S ribosomal RNA (rRNA) gene, the 16S–23S rRNA intergenic spacer region (ISR); by sequencing the target genes rpoB, gap, and tuf; and by detection of T. pyogenes chaperonin-encoding gene cpn60 with a previously developed loop-mediated isothermal amplification (LAMP) assay. The T. pyogenes strain could additionally be characterized by PCR-mediated amplification of several known and putative virulence factor-encoding genes which revealed the presence of the genes plo encoding pyolysin and nanH and nanP encoding neuraminidases; the genes fimA, fimC, and fimE encoding the fimbrial subunits FimA, FimC, and FimE; and the gene cbpA encoding collagen-binding protein CbpA. The present data give a detailed characterization of a T. pyogenes strain isolated from a brain abscess of a roebuck. However, the route of infection of the roebuck remains unclear.  相似文献   

8.
The rise of antibiotic resistance in pathogenic bacteria is endangering the efficacy of antibiotics, which consequently results in greater use of silver as a biocide. Chromosomal mapping of the Cus system or plasmid encoded Sil system and their relationship with silver resistance was studied for several gram-negative bacteria. However, only few reports investigated silver detoxification mediated by the Sil system integrated in Escherichia coli chromosome. Accordingly, this work aimed to study the Sil system in E. coli ATCC 8739 and to produce evidence for its role in silver resistance development. Silver resistance was induced in E. coli ATCC 8739 by stepwise passage in culture media containing increasing concentrations of AgNO3. The published genome of E. coli ATCC 8739 contains a region showing strong homology to the Sil system genes. The role of this region in E. coli ATCC 8739 was assessed by monitoring the expression of silC upon silver stress, which resulted in a 350-fold increased expression. De novo sequencing of the whole genome of a silver resistant strain derived from E. coli ATCC 8739 revealed mutations in ORFs putative for SilR and CusR. The silver resistant strain (E. coli AgNO3R) showed constitutive expression of silC which posed a cost of fitness resulting in retarded growth. Furthermore, E. coli AgNO3R exhibited cross-resistance to ciprofloxacin and a slightly increased tolerance to ampicillin. This study demonstrates that E. coli is able to develop resistance to silver, which may pose a threat towards an effective use of silver compounds as antiseptics.  相似文献   

9.
This study aimed to disclose the acid tolerance mechanism of Lactobacillus plantarum by comparing L. plantarum ZDY 2013 with the type strain L. plantarum ATCC 8014 in terms of cell membrane, energy metabolism, and amino acid metabolism. L. plantarum ZDY 2013 had a superior growth performance under acidic condition with 100-fold higher survival rate than that of L. plantarum ATCC 8014 at pH 2.5. To determine the acid tolerance physiological mechanism, cell integrity was investigated through scanning electron microscopy. The study revealed that L. plantarum ZDY 2013 maintained cell morphology and integrity, which is much better than L. plantarum ATCC 8014 under acid stress. Analysis of energy metabolism showed that, at pH 5.0, L. plantarum ZDY 2013 enhanced the activity of Na+/K+-ATPase and decreased the ratio of NAD+/NADH in comparison with L. plantarum ATCC 8014. Similarly, amino acid metabolism of intracellular arginine, glutamate, and alanine was improved in L. plantarum ZDY 2013. Correspondingly, the activity of arginine deiminase and glutamate decarboxylase of L. plantarum ZDY 2013 increased by 1.2-fold and 1.3-fold compared with L. plantarum ATCC 8014 in acid stress. In summary, it is demonstrated that the special physiological behaviors (integrity of cell membrane, enhanced energy metabolism, increased amino acid and enzyme level) of L. plantarum ZDY 2013 can protect the cells from acid stress.  相似文献   

10.
11.

Objective

To improve the production of welan gum and obtain a carotenoid-free strain while reducing the fermentation and post-treatment costs.

Results

The vitreoscilla globin (vgb) gene combined with the β-galactosidase (lacZ) promoter was inserted into the phytoene synthase (crtB) gene region of the chromosome in Alcaligenes sp. ATCC31555. When the recombinant strain was grown in a 5 l fermentor, welan gum was produced at 24 ± 0.4 g l?1 compared to 21 g ± 0.4 g l?1 in the wild type. Furthermore, the carotenoid-free welan gum produced using Alcaligenes sp. ATCC31555 VHb strain was less expensive with improved properties.

Conclusions

Alcaligenes sp. ATCC31555 VHb strain was a better neutral welan-producing strain with a higher production than the wild-type strain.
  相似文献   

12.
A novel Gram-stain positive, spore-forming, aerobic actinomycete, designated strain NEAU-QTH3-11T, was isolated from muddy soil collected from a stream in Qitaihe, Heilongjiang Province, northeast China and characterised using a polyphasic approach. The 16S rRNA gene sequence analysis showed that strain NEAU-QTH3-11T belongs to the genus Streptomyces and is closely related to Streptomyces rhizosphaerihabitans NBRC 109807T (99.38%) and Streptomyces mirabilis JCM 4791T (99.03%). Phylogenetic analysis based on the 16S rRNA gene sequences indicated that the strain formed a cluster with S. rhizosphaerihabitans NBRC 109807T and Streptomyces siamensis NBRC 108799T (98.62%). The menaquinones were identified as MK-9(H8), MK-9(H6) and MK-9(H4). The phospholipid profile was found to consist of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol, an unidentified phospholipid and an unidentified lipid. The major fatty acids were identified as anteiso-C15:0, iso-C16:0, C16:0 and C15:0. However, multilocus sequence analysis based on five house-keeping genes (atpD, gyrB, rpoB, recA and trpB), low DNA-DNA hybridization results and some phenotypic, physiological and biochemical properties could differentiate the strain from its close relatives in the genus Streptomyces. Therefore, strain NEAU-QTH3-11T is considered to represent a novel species of the genus Streptomyces, for which the name Streptomyces lutosisoli sp. nov. is proposed, with NEAU-QTH3-11T (=DSM 42165T=CGMCC 4.7198T) as the type strain.  相似文献   

13.
The gene encoding the xlnR xylanolytic activator of the heterologous fungus Aspergillus niger was incorporated into the Penicillium canescens genome. Integration of the xlnR gene resulted in the increase in a number of activities, i.e. endoxylanase, β-xylosidase, α-L-arabinofuranosidase, α-galactosidase, and feruloyl esterase, compared to the host P. canescens PCA 10 strain, while β-galactosidase, β-glucosidase, endoglucanase, and CMCase activities remained constant. Two different expression constructs were developed. The first consisted of the nucleotide sequence containing the mature P. canescens phytase gene under control of the axhA promoter region gene encoding A. niger (1,4)-β-D-arabinoxylan-arabinofuranohydrolase. The second construct combined the P. canescens phytase gene and the bgaS promoter region encoding homologous β-galactosidase. Both expression cassettes were transformed into P. canescens host strain containing xlnR. Phytase synthesis was observed only for strains with the bgaS promoter on arabinose-containing culture media. In conclusion, the bgaS and axhA promoters were regulated by different inducers and activators in the P. canescens strain containing a structural tandem of the axhA promoter and the gene of the xlnR xylanolytic activator.  相似文献   

14.
The probiotic characteristics of Lactobacillus curvatus DN317, a strain isolated from chicken ceca, were evaluated. This strain was selected for study from the isolated Lactobacillus strains because it has specific anti-microbial activity against Campylobacter jejuni ATCC 33560, Camp. jejuni NCTC 11168, Listeria monocytogenes ATCC 7644, and Bacillus subtilis ATCC 8633. Lact. curvatus DN317 showed an auto-aggregation percentage of 72% and presented the highest co-aggregation with Lact. monocytogenes ATCC 7644 (68%) compared to B. subtilis ATCC 8633 (45%), Camp. jejuni ATCC 33560 (36%), and Camp. jejuni NCTC 11168 (35%). The data revealed that Lact. curvatus DN317 could survive at 0.25% bile, maintain viability at pH 2.5 for 30 min, produce biosurfactants, and adhere to Caco-2 cells. Quantification of IL-6, IL-8, IL-10, and β-defensin 2 levels shows that Lact. curvatus DN317 induces an increase in IL-8 and β-defensin 2 secretion, while the levels of IL-6 and IL-10 do not change. Lact. curvatus DN317 showed high levels of esterase and cysteine arylamidase activities (5); moderate levels of esterase lipase, β-galactosidase, and α-galactosidase activities (4, 3); and weak levels of leucine arylamidase, valine arylamidase, and acid phosphatase activity (1). Various activities were obtained of α-chymotrypsin, β-glucuronidase, β-glucosidase, and N-acetyl-β-glucosaminidase, which have been associated with intestinal diseases. Lact. curvatus DN317 lowered the cholesterol level in MRS with and without bile. Antibiotic susceptibility tests indicated that DN317 was sensitive to ampicillin, gentamicin, kanamycin, streptomycin, tetracycline, clindamycin, erythromycin, and vancomycin but was resistant to chloramphenicol and ciprofloxacin. These results suggest that Lact. curvatus DN317 could potentially function as a probiotic.  相似文献   

15.
Actinomycete strain AUM 00500 was 99.5 % similar to Streptomyces sanglieri NBRC 100784T and was evaluated for antagonistic activity towards Ganoderma boninense, the causative fungus of basal stem rot of oil palm. The strain showed strong antifungal activity towards G. boninense in in vitro and SEM analysis showed various modes of inhibition of the fungus. Ethyl acetate extracts of single culture and inhibition zone of cross-plug culture by HPLC indicated that strain AUM 00500 produced two different antibiotics of the glutarimide group namely cycloheximide and actiphenol. In greenhouse trials, oil palm seed treated with spores of S. sanglieri strain AUM 00500 at 109 cfu/ml showed significant (P < 0.05) increase in oil palm seedlings growth when compared to the control. Streptomyces sanglieri strain AUM 00500 successfully colonised the epidermal surface of the roots of treated oil palm seedlings and it was recovered from root fragments plated on starch casein agar.  相似文献   

16.
17.
Selectable marker genes are widely used for the efficient transformation of crop plants. In most cases, selection is based on antibiotic or herbicide resistance genes because they tend to be most efficient. The Synechococcus hemL gene has been successfully employed as a selectable marker for tobacco and alfalfa genetic transformation, by using gabaculine as the selective agent. The gene conferring gabaculine resistance is a mutant form of the hemL gene from Synechococcus PCC6301, strain GR6, encoding a gabaculine insensitive form of the glutamate1-semialdehyde aminotransferase (GSA) enzyme. In the present study we compared the transformation and selection efficiency of the common selection method based on the Streptomyces hygroscopicus bar gene conferring resistance to Bialaphos®, with both the Synechococcus hemL gene and a Medicago sativa mutated GSA gene (MsGSAgr) conferring resistance to phytotoxin gabaculine. Callus derived from immature embryos of the durum wheat cultivar Varano were simultaneously co-bombarded with bar/hemL and bar/MsGSAgr genes. After gene delivery, the marker genes were individually evaluated through all the selection phases from callus regeneration to adult plant formation, and compared for their transformation and selection efficiency. The integration of the three genes in the T0 generation was confirmed by PCR analysis with specific primers for each gene and southern blot analysis. Both Synechococcus hemL and MsGSA were more efficient than bar for biolistic transformation (2.8% vs. 1.8% and 1.1% vs. 0.5%) and selection (79% vs. 43% and 87% vs. 50%). Thus, an efficient selection method for durum wheat transformation was established that obviates the use of herbicide resistance genes.  相似文献   

18.
A novel actinomycete strain, designated TRM 49605T, was isolated from a desert soil sample from Lop Nur, Xinjiang, north-west China, and characterised using a polyphasic taxonomic approach. The strain exhibited antifungal activity against the following strains: Saccharomyces cerevisiae, Curvularia lunata, Aspergillus flavus, Aspergillus niger, Fusarium oxysporum, Penicillium citrinum, Candida albicans and Candida tropicalis; Antibacterial activity against Bacillus subtilis, Staphylococcus epidermidis and Micrococcus luteus; and no antibacterial activity against Escherichia coli. Phylogenetic analysis based on 16S rRNA gene sequences affiliated strain TRM 49605T to the genus Streptomyces. Strain TRM 49605T shows high sequence similarities to Streptomyces roseolilacinus NBRC 12815T (98.62 %), Streptomyces flavovariabilis NRRL B-16367T (98.45 %) and Streptomyces variegatus NRRL B-16380T (98.45 %). Whole cell hydrolysates of strain TRM 49605T were found to contain ll-diaminopimelic acid as the diagnostic diamino acid and galactose, glucose, xylose and mannose as the major whole cell sugars. The major fatty acids in strain TRM 49605T were identified as iso C16:0, anteiso C15:0, C16:0 and Summed Feature 5 as defined by MIDI. The main menaquinones were identified as MK-9(H4), MK-9(H6), MK-9(H8) and MK-10(H6). The polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, phosphatidylinositol and phosphatidylinositol mannoside. The G+C content of the genomic DNA was determined to be 71.2 %. The DNA–DNA relatedness between strain TRM 49605T and the phylogenetically related strain S. roseolilacinus NBRC 12815T was 60.12 ± 0.06 %, which is lower than the 70 % threshold value for delineation of genomic prokaryotic species. Based on the phenotypic, chemotaxonomic and phylogenetic data, strain TRM 49605T (=CCTCC AA2015026T = KCTC 39666T) should be designated as the type strain of a novel species of the genus Streptomyces, for which the name Streptomyces luozhongensis sp. nov. is proposed.  相似文献   

19.
In the current investigation, the biological activities of essential oils obtained from organs of Ruta chalepensis plants grown under salt stress (0, 50 and 100 mM NaCl) were analyzed. Their chemical composition was often investigated by GC/FID and GC–MS and the antimicrobial activities towards eight bacteria (Salmonella All, Salmonella K, Escherichia coli 45AG, Escherichia coli 45AI, Staphylococcus aureus 9402, Staphylococcus aureus 02B145, Listeria 477 and Pseudomonas aeruginosa ATCC 10145) and five fungi strains (Aspergillus, Saccharomycee crvisiale, Streptomyces griseus, Fusarium solani and Penicillium thomii) were studied. Results revealed that salt increased essential oil production in leaves at 50 and 100 mM NaCl. A total of 20 compounds were identified in leaves, undecan-2-one, nonan-2-one and geijerene being the dominant ones. In stems, 21 compounds were found; they were dominated by decan-2-one, geijerene, nonan-2-one and undecan-2-one. In contrast, roots exhibited a large variation with 25 volatile compounds and octyl acetate, methyl decanoate, phytyl acetate were the major ones. Salt stress induced significant antibacterial activity changes, mainly in leaves and stems. In leaves, the minimum inhibitory and bactericidal concentration decreased at 100 mM NaCl against Listeria 477, the two strains of E. coli (45AG and 45AI) and P. aeruginosa but it increased versus other bacteria. In stems, salt increased oil antibacterial activity against all strains except P. aeruginosa ATCC 10145. Root oil showed the least antibacterial activity under saline conditions versus Listeria 477 and P. aeruginosa ATCC 10145. As regards antifungal activity, NaCl reduced the antifungal activity of essential oils against the majority of fungi strains.  相似文献   

20.
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