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Sample records for brevibacterium

  1. Ectoine accumulation in Brevibacterium epidermis.

    Science.gov (United States)

    Onraedt, Annelies; De Muynck, Cassandra; Walcarius, Bart; Soetaert, Wim; Vandamme, Erick

    2004-10-01

    As a halotolerant bacterial species, Brevibacterium epidermis DSM 20659 can grow at relatively high salinity, tolerating up to 2 M NaCl. It synthesizes ectoine and the intracellular content increases with the medium salinity, with a maximum of 0.14 g ectoine/g CDW at 1 M NaCl. Sugar-stressed cells do not synthesize ectoine. Ectoine synthesis is also affected by the presence of external osmolytes. Added betaine is taken up and completely replaced ectoine, while L-proline is only temporarily accumulated after which ectoine is synthesized. The strain can metabolize ectoine; L-glutamate is a better carbon source for ectoine synthesis than L-aspartate.

  2. Growth stimulation of Brevibacterium sp. by siderophores

    NARCIS (Netherlands)

    Noordman, W.H.; Reissbrodt, R.; Bongers, R.S.; Rademaker, J.L.W.; Bockelmann, W.; Smit, G.

    2006-01-01

    To assess which types of siderophores are typically produced by Brevibacterium and how siderophore production and utilization traits are distributed within this genus. Methods and Results: During co-cultivation experiments it was found that growth of B. linens Br5 was stimulated by B. linens NIZO B1

  3. Degradation of ochratoxin a by Brevibacterium species.

    Science.gov (United States)

    Rodriguez, Hector; Reveron, Ines; Doria, Francesca; Costantini, Antonella; De Las Rivas, Blanca; Muňoz, Rosario; Garcia-Moruno, Emilia

    2011-10-12

    The ability to degrade ochratoxin A was studied in different bacteria with a well-known capacity to transform aromatic compounds. Strains belonging to Rhodococcus, Pseudomonas, and Brevibacterium genera were grown in liquid synthetic culture medium containing ochratoxin A. Brevibacterium spp. strains showed 100% degradation of ochratoxin A. Ochratoxin α was detected and identified by high-performance liquid chromatography-mass spectrometry (HPLC-MS) as a degradation product in the cell-free supernatants. The degradation of ochratoxin A is of public concern for food and environmental safety, because it could contribute to the development of new biological ochratoxin A detoxification systems in foodstuffs. In this study, the degradation of ochratoxin A by bacteria belonging to the food chain was demonstrated for the first time.

  4. Reclassification of Brevibacterium incertum (Breed 1953) as Desemzia incerta gen. nov., comb. nov.

    Science.gov (United States)

    Stackebrandt, E; Schumann, P; Swiderski, J; Weiss, N

    1999-01-01

    Phylogenetic analysis of 16S rDNA indicates that Brevibacterium incertum is not a member of the genus Brevibacterium but related to species of the genus Carnobacterium. Hence, Brevibacterium incertum is not a member of the class Actinobacteria but belongs to the phylogenetically defined broad Bacillus-Lactobacillus cluster. Based upon properties that taxonomically clearly distinguishes Brevibacterium incertum from species of the phylogenetic sister genus Carnobacterium, Brevibacterium incertum is reclassified as Desemzia incerta gen. nov., comb. nov.

  5. Brevibacterium otitidis: an elusive cause of neurosurgical infection.

    LENUS (Irish Health Repository)

    Fe Talento, Alida

    2013-03-01

    Coryneform bacteria are usually considered as non-pathogenic when isolated from clinical specimens. We present a case of Brevibacterium otitidis neurosurgical infection in an immunocompetent patient, and highlight the difficulty with identification and interpretation of antimicrobial susceptibility results for this unusual pathogen.

  6. Transport kinetics of ectoine, an osmolyte produced by Brevibacterium epidermis.

    Science.gov (United States)

    Onraedt, A; De Mey, M; Walcarius, B; Soetaert, W; Vandamme, E J

    2006-11-01

    Brevibacterium epidermis DSM 20659 is a halotolerant Gram-positive bacterium which can synthesize the osmolyte, ectoine, but prefers to take it up from its environment. The present study revealed that B. epidermis is equipped with at least one transport system for ectoine, with a maximal transport velocity of 15.7 +/- 4.3 nmol/g CDW.min. The transport requires energy (ATP) and is completely inhibited by the proton uncoupler, CCCP. The ectoine uptake system is constitutively expressed at a basal level of activity and its activity is immediately 10-fold increased by hyper-osmotic stress. Initial uptake rates are not influenced by the intensity of the hyper-osmotic shock but the duration of the increased activity of the uptake system could be directly related to the osmotic strength of the assay solution. Competition assays indicate that betaine, but not proline, is also transported by the ectoine uptake system.

  7. Brevibacterium pityocampae sp. nov., isolated from caterpillars of Thaumetopoea pityocampa (Lepidoptera, Thaumetopoeidae).

    Science.gov (United States)

    Kati, Hatice; Ince, Ikbal Agah; Demir, Ismail; Demirbag, Zihni

    2010-02-01

    This work deals with the taxonomic study of a bacterium, strain Tp12(T), isolated from caterpillars of the pine processionary moth (Thaumetopoea pityocampa Denis & Schiffermüller, 1775; Lepidoptera, Thaumetopoeidae). The isolate was assigned to the genus Brevibacterium on the basis of a polyphasic taxonomic study, including morphological and biochemical characteristics, 16S rRNA gene sequence analysis, fatty acid analysis and DNA G+C content. The highest 16S rRNA gene sequence similarity to this isolate was approximately 96 %, with the type strains of Brevibacterium album and Brevibacterium samyangense. Cellular fatty acids of the isolate are of the branched type, with the major components being anteiso-C(15 : 0) and anteiso-C(17 : 0). The DNA G+C content was 69.8 mol%. Although the strain was related to B. album and B. samyangense according to 16S rRNA gene sequence analysis, it differed from any known species of Brevibacterium. Based on this evidence, the novel species Brevibacterium pityocampae sp. nov. is proposed, with strain Tp12(T) (=DSM 21720(T) =NCCB 100255(T)) as the type strain.

  8. Purification and Characterization of an Extracellular Proteinase from Brevibacterium-Linens ATCC-9174

    DEFF Research Database (Denmark)

    Rattray, F P; Bockelmann, W; Fox, P F

    1995-01-01

    An extracellular serine proteinase from Brevibacterium linens ATCC 9174 was purified to homogeneity. pH and temperature optima were 8,5 and 50 degrees C, respectively. The results for the molecular mass of the proteinase were 56 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and...

  9. Efficient utilization of ectoine by halophilic Brevibacterium species and Escherichia coli subjected to osmotic downshock.

    Science.gov (United States)

    Nagata, Shinichi; Wang, Chenxiang

    2005-01-01

    Halophilic and non-halophilic bacteria subjected to osmotic downshock, from 0.7 M NaCl to deionized water, were examined for their survival, with the uptake and utilization of the cyclic amino acid ectoine, one of the representative compatible solutes, being taken into account. The uptake of ectoine added externally and survival of the cells were monitored as a function of incubation time in the presence and absence of NaCl. The halophilic Brevibacterium sp. JCM 6894 and B. epidermidis JCM 2593 actively accumulated ectoine regardless of the presence of NaCl, which led to cell survival. Brevibacterium casei JCM 2594 belonging to the same Brevibacterium species, however, revealed Na+-dependence of its uptake activity of ectoine. Non-halophilic Escherichia coli K-12 did not accumulate ectoine, and thereby this strain failed to survive irrespective of whether NaCl was present. The physiological meanings of the downshock procedure are discussed in connection with the uptake and the subsequent utilization of ectoine.

  10. Recent advances in recombinant protein expression by Corynebacterium, Brevibacterium, and Streptomyces: from transcription and translation regulation to secretion pathway selection.

    Science.gov (United States)

    Liu, Long; Yang, Haiquan; Shin, Hyun-Dong; Li, Jianghua; Du, Guocheng; Chen, Jian

    2013-11-01

    Gram-positive bacteria are widely used to produce recombinant proteins, amino acids, organic acids, higher alcohols, and polymers. Many proteins have been expressed in Gram-positive hosts such as Corynebacterium, Brevibacterium, and Streptomyces. The favorable and advantageous characteristics (e.g., high secretion capacity and efficient production of metabolic products) of these species have increased the biotechnological applications of bacteria. However, owing to multiplicity from genes encoding the proteins and expression hosts, the expression of recombinant proteins is limited in Gram-positive bacteria. Because there is a very recent review about protein expression in Bacillus subtilis, here we summarize recent strategies for efficient expression of recombinant proteins in the other three typical Gram-positive bacteria (Corynebacterium, Brevibacterium, and Streptomyces) and discuss future prospects. We hope that this review will contribute to the development of recombinant protein expression in Corynebacterium, Brevibacterium, and Streptomyces.

  11. Brevibacterium frigoritolerans as a Novel Organism for the Bioremediation of Phorate.

    Science.gov (United States)

    Jariyal, Monu; Gupta, V K; Mandal, Kousik; Jindal, Vikas

    2015-11-01

    Phorate, an organophosphorus insecticide, has been found effective for the control of various insect pests. However, it is an extremely hazardous insecticide and causes a potential threat to ecosystem. Bioremediation is a promising approach to degrade the pesticide from the soil. The screening of soil from sugarcane fields resulted in identification of Brevibacterium frigoritolerans, a microorganism with potential for phorate bioremediation was determined. B. frigoritolerans strain Imbl 2.1 resulted in the active metabolization of phorate by between 89.81% and 92.32% from soils amended with phorate at different levels (100, 200, 300 mg kg(-1) soil). But in case of control soil, 33.76%-40.92% degradation were observed. Among metabolites, sulfone was found as the main metabolite followed by sulfoxide. Total phorate residues were not found to follow the first order kinetics. This demonstrated that B. frigoritolerans has potential for bioremediation of phorate both in liquid cultures and agricultural soils.

  12. Some enzymatic properties of cholesterol oxidase produced by Brevibacterium sp Algumas propriedades enzimáticas da colesterol oxidase produzida por Brevibacterium sp.

    Directory of Open Access Journals (Sweden)

    Terezinha J.G. Salva

    1999-12-01

    Full Text Available In this study we determined some properties of the cholesterol oxidase from a Brevibacterium strain isolated from buffalo's milk and identified the cholesterol degradation products by the bacterial cell. A small fraction of the enzyme synthesized by cells cultured in liquid medium for 7days was released into the medium whereas a larger fraction remained bound to the cell membrane. The extraction of this fraction was efficiently accomplished in 1 mM phosphate buffer, pH 7.0, containing 0.7% Triton X-100. The enzyme stability under freezing and at 45oC was improved by addition of 20% glycerol. The optimum temperature and pH for the enzyme activity were 53°C and 7.5, respectively. The only steroidal product from cholesterol oxidation by the microbial cell and by the crude extract of the membrane-bound enzyme was 4-colesten-3-one. Chromatographic analysis showed that minor no steroidal compounds as well as 4-colesten-3-one found in the reaction media arose during fermentation process and were extracted together with the enzyme in the buffer solution. Cholesterol oxidation by the membrane-bound enzyme was a first order reaction type.Neste trabalho foram definidas algumas propriedades da enzima colesterol oxidase produzida por uma linhagem de Brevibacterium sp. isolada de leite de búfala e foram identificados os compostos resultantes da degradação do colesterol pela bactéria. Uma pequena fração da enzima sintetizada pelas células cultivadas em meio líquido por 7 dias foi liberada no meio de cultura e uma fração maior permaneceu ligada à membrana celular. A extração desta fração foi eficientemente efetuada em tampão fosfato 1mM, pH 7,0, contendo 0,7% de triton X-100. A estabilidade da enzima congelada e a 45oC foi aumentada pela adição de 20% de glicerol. A temperatura ótima para a atividade enzimática esteve ao redor de 53(0C e o pH ótimo esteve ao redor de 7,5. O único produto da degradação do colesterol, causada pela a

  13. Growth characteristics of Brevibacterium, Corynebacterium, Microbacterium, and Staphylococcus spp. isolated from surface-ripened cheese.

    Science.gov (United States)

    Mounier, Jérôme; Rea, Mary C; O'Connor, Paula M; Fitzgerald, Gerald F; Cogan, Timothy M

    2007-12-01

    The growth characteristics of five bacteria, Brevibacterium aurantiacum 1-16-58, Corynebacterium casei DPC 5298(T), Corynebacterium variabile DPC 5310, Microbacterium gubbeenense DPC 5286(T), and Staphylococcus saprophyticus 4E61, all of which were isolated from the surface of smear cheese, were studied in complex and chemically defined media. All of the coryneforms, except M. gubbeenense, grew in 12% salt, while B. aurantiacum and S. saprophyticus grew in 15% salt. All five bacteria assimilated lactate in a semisynthetic medium, and none of the coryneform bacteria assimilated lactose. Glucose assimilation was poor, except by S. saprophyticus and C. casei. Five to seven amino acids were assimilated by the coryneforms and 12 by S. saprophyticus. Glutamate, phenylalanine, and proline were utilized by all five bacteria, whereas utilization of serine, threonine, aspartate, histidine, alanine, arginine, leucine, isoleucine, and glycine depended on the organism. Growth of C. casei restarted after addition of glutamate, proline, serine, and lactate at the end of the exponential phase, indicating that these amino acids and lactate can be used as energy sources. Pantothenic acid was essential for the growth of C. casei and M. gubbeenense. Omission of biotin reduced the growth of B. aurantiacum, C. casei, and M. gubbeenense. All of the bacteria contained lactate dehydrogenase activity (with both pyruvate and lactate as substrates) and glutamate pyruvate transaminase activity but not urease activity.

  14. Efficient cyclic system to yield ectoine using Brevibacterium sp. JCM 6894 subjected to osmotic downshock.

    Science.gov (United States)

    Nagata, Shinichi; Wang, Yaoqiang; Oshima, Akinobu; Zhang, Linghua; Miyake, Hideyoshi; Sasaki, Hideaki; Ishida, Akio

    2008-03-01

    Brevibacterium sp. JCM 6894 cells grown in the presence of 1.5-2.5 M NaCl for 24 h at 30 degrees C were subjected to the osmotic downshock. Downshocked cells after ectoine release were grown for further 24 h in the fresh medium with same salinity as before shock. When this cyclic system was applied to the strain JCM 6894, the amount of ectoine in the cells increased with an increase of incubation time, which indicates that the cells manipulated by the present conditions were enough active to survive and synthesize ectoine after several times of osmotic downshock. In the presence of 2 M NaCl, the highest yield of ectoine released was achieved in this cyclic system, more than 2.4 g/L during 7 days of incubation. (1)H and (13)C-NMR analyses of solutes released from the cells by the osmotic downshock showed the presence of only ectoine with high purity. Release of ectoine from the cells was carried out within 5 min and its rates were increased by the dilution in the downshock treatment. For the convenience of operations, non-sterilized medium containing 2 M NaCl was examined for the cell growth in the present system, in which almost same level of ectoine yield, release rates, and cell viability were observed as those of sterilized medium.

  15. Optimization of ectoine synthesis through fed-batch fermentation of Brevibacterium epidermis.

    Science.gov (United States)

    Onraedt, Annelies E; Walcarius, Bart A; Soetaert, Wim K; Vandamme, Erick J

    2005-01-01

    A production process for ectoine has been developed, using Brevibacterium epidermis DSM20659 as the producer strain. First, the optimal conditions for intracellular synthesis of ectoine were determined. The size of the intracellular ectoine pool is shown to be dependent on the external salt concentration, type of carbon source, and yeast extract concentration. Under the optimized conditions of 1 M NaCl, 50 g/L monosodium glutamate, and 2.5 g/L yeast extract, a maximum concentration of intracellular ectoine of 0.9 g/L was obtained in shake flask cultures. After optimizing the batch fermentation parameters of temperature, pH, agitation, and aeration, the yield could be further increased by applying the fed-batch fermentation principle in 1.5- to 2-L fermentors. Glutamate and yeast extract were fed to the bacterial cells such that the total glutamate concentration in the broth remained constant. A total yield of 8 g ectoine/L fermentation broth was obtained with a productivity of 2 g ectoine/L/day. After the bacterial cells were harvested from the culture broth, the ectoine was recovered from them by a two-step extraction with water and ethanol. Crystallization of the product was obtained after concentration of the extract via evaporation under reduced pressure. After this downstream process, 55% of the ectoine produced in the fermentor could be crystallized in four fractions. The first fractions were of very high purity (98%). This production process can compete with other described production processes for ectoine in productivity and simplicity. Further advantages are the relatively low amounts of NaCl needed and the absence of hydroxyectoine, often a byproduct, in the final product.

  16. Co-expression of five genes in E coli for L-phenylalanine in Brevibacterium fiavum

    Institute of Scientific and Technical Information of China (English)

    Yong-Qing Wu; Pei-Hong Jiang; Chang-Sheng Fan; Jian-Gang Wang; Liang Shang; Wei-Da Huang

    2003-01-01

    AIM: To study the effect of co-expression of ppsA, pckA,aroG, pheA and tyrB genes on the production of L-phenylalanine, and to construct a genetic engineering strainfor L-phenylalanine.METHODS: ppsA and pckA genes were amplified fromgenomic DNA of E. coli by polymerase chain reaction, andthen introduced into shuttle vectors between E coli andBrevibacterium flavumto generate constructs pJN2 and pJN5.pJN2 was generated by inserting ppsA and pckA genes intovector pCZ; whereas pJN5 was obtained by introducing ppsAand pckA genes into pCZ-GAB, which was originallyconstructed for co-expression of aroG, pheA and tyrB genes.The recombinant plasmids were then introduced into B.flavum by electroporation and the transformants were usedfor L-phenylalanine fermentation.RESULTS: Compared with the original B. flavum cells, all the transformants were showed to have increased five enzyme activities specifically, and have enhanced Lphenylalanine biosynthesis ability variably. pJN5 transformant was observed to have the highest elevation of Lphenylalanine production by a 3.4-fold. Co-expression of ppsA and pckA increased activity of DAHP synthetase significantly.CONCLUSION: Co-expression of ppsA and pckA genes in B. flavum could remarkably increase the expression of DAHP synthetase; Co-expression of ppsA, pckA, aroG, pheA and tyrB of E. coli in B. flavum was a feasible approach toconstruct a strain for phenylalanine production.

  17. Simultaneous identification of two cyclohexanone oxidation genes from an environmental Brevibacterium isolate using mRNA differential display.

    Science.gov (United States)

    Brzostowicz, P C; Gibson, K L; Thomas, S M; Blasko, M S; Rouvière, P E

    2000-08-01

    The technique of mRNA differential display was used to identify simultaneously two metabolic genes involved in the degradation of cyclohexanone in a new halotolerant Brevibacterium environmental isolate. In a strategy based only on the knowledge that cyclohexanone oxidation was inducible in this strain, the mRNA population of cells exposed to cyclohexanone was compared to that of control cells using reverse transcription-PCR reactions primed with a collection of 81 arbitrary oligonucleotides. Three DNA fragments encoding segments of flavin monooxygenases were isolated with this technique, leading to the identification of the genes of two distinct cyclohexanone monooxygenases, the enzymes responsible for the oxidation of cyclohexanone. Each monooxygenase was expressed in Escherichia coli and characterized. This work validates the application of mRNA differential display for the discovery of new microbial metabolic genes.

  18. Phenylalanine biosynthesis in Brevibacterium lactofermentum using Escherichia coli genes pheA, aroG and tyrB

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Genetic engineering technology to increase the production of L-phenylalanine was used in the study.Three genes encoding the key enzymes involved in the biosynthesis of L-phenylalanine were utilized, in which the gene aroG encodes 3-deoxy-D-arabino-heptulosonate-7-phosphate synthetase (DS); the gene pheA encodes bifunctional enzyme of chorisate mutase (CM) and prephenate dehydratase (PD); and the gene tyrb encodes aminotransferase (AT).The three genes were amplified by polymerase chain reaction (PCR) from the genome of the E. coli mutant strains resistant to fluro-DL-phenylalanine and inserted into the cloning vectors. Then, they were expressed in E. coli and Brevibacterium lactofermentum in a tandem arrangement. The expressed enzymes had high activities in the host cells.

  19. Genome analysis shows Bacillus axarquiensis is not a later heterotypic synonym of Bacillus mojavensis; reclassification of Bacillus malacitensis and Brevibacterium halotolerans as heterotypic synonyms of Bacillus axarquiensis.

    Science.gov (United States)

    Dunlap, Christopher A; Bowman, Michael J; Schisler, David A; Rooney, Alejandro P

    2016-06-01

    Bacillus axarquiensis and Bacillus malacitensis were previously reported to be later heterotypic synonyms of Bacillus mojavensis, based primarily on DNA-DNA relatedness values. We have sequenced draft genomes of Bacillus axarquiensis NRRL B-41617T and Bacillus malacitensis NRRL B-41618T. Comparative genomics and DNA-DNA relatedness calculations showed that while Bacillus axarquiensis and Bacillus malacitensis are synonymous with each other, they are not synonymous with Bacillus mojavensis. In addition, a draft genome was completed for Brevibacterium halotolerans, a strain long suspected of being a Bacillus subtilis group member based on 16S rRNA similarities (99.8 % with Bacillus mojavensis). Comparative genomics and DNA-DNA relatedness calculations showed that Brevibacterium halotolerans is synonymous with Bacillus axarquiensis and Bacillus malacitensis. The pairwise in silico DNA-DNA hybridization values calculated in comparisons between the three conspecific strains were all greater than 92 %, which is well above the standard species threshold of 70 %. While the pairwise in silico DNA-DNA hybridization values calculated in comparisons of the three conspecific strains with Bacillus mojavensis were all less than 65 %. The combined results of our genotype and phenotype studies showed that Bacillus axarquiensis, Bacillus malacitensis and Brevibacterium halotolerans are conspecific and distinct from Bacillus mojavensis. Because the valid publication of the name Bacillus axarquiensis predates the publication of the name Bacillus malacitensis, we propose that Bacillus malacitensis be reclassified as a synonym of Bacillus axarquiensis. In addition, we propose to reclassify Brevibacterium halotolerans as a synonym of Bacillus axarquiensis. An amended description of Bacillus axarquiensis is provided.

  20. Brevibacterium metallicus sp. nov., an endophytic bacterium isolated from roots of Prosopis laegivata grown at the edge of a mine tailing in Mexico.

    Science.gov (United States)

    Román-Ponce, Brenda; Li, Yong Hua; Vásquez-Murrieta, María Soledad; Sui, Xin Hua; Chen, Wen Feng; Estrada-de Los Santos, Paulina; Wang, En Tao

    2015-12-01

    A Gram-positive, aerobic, nonmotile strain, NM2E3(T) was identified as Brevibacterium based on the 16S rRNA gene sequence analysis and had the highest similarities to Brevibacterium jeotgali SJ5-8(T) (97.3 %). This novel bacterium was isolated from root tissue of Prosopis laegivata grown at the edge of a mine tailing in San Luis Potosí, Mexico. Its cells were non-spore-forming rods, showing catalase and oxidase activities and were able to grow in LB medium added with 40 mM Cu(2+), 72 mM As(5+) and various other toxic elements. Anteiso-C15:0 (41.6 %), anteiso-C17:0 (30 %) and iso-C15:0 (9.5 %) were the major fatty acids. MK-8(H2) (88.4 %) and MK-7(H2) (11.6 %) were the major menaquinones. The DNA G + C content of the strain NM2E3(T) was 70.8 mol % (Tm). DNA-DNA hybridization showed that the strain NM2E3(T) had 39.8, 21.7 and 20.3 % relatedness with B. yomogidense JCM 17779(T), B. jeotgali JCM 18571(T) and B. salitolerans TRM 45(T), respectively. Based on the phenotypic and genotypic analyses, the strain NM2E3(T) (=CCBAU 101093(T) = HAMBI 3627(T) = LMG 8673(T)) is reported as a novel species of the genus Brevibacterium, for which the name Brevibacterium metallicus sp. nov., is proposed.

  1. Decolorization and biodegradation of reactive sulfonated azo dyes by a newly isolated Brevibacterium sp. strain VN-15.

    Science.gov (United States)

    Franciscon, Elisangela; Grossman, Matthew James; Paschoal, Jonas Augusto Rizzato; Reyes, Felix Guillermo Reyes; Durrant, Lucia Regina

    2012-12-01

    Azo dyes constitute the largest and most versatile class of synthetic dyes used in the textile, pharmaceutical, food and cosmetics industries and represent major components in wastewater from these industrial dying processes. Biological decolorization of azo dyes occurs efficiently under low oxygen to anaerobic conditions. However, this process results in the formation of toxic and carcinogenic amines that are resistant to further detoxification under low oxygen conditions. Moreover, the ability to detoxify these amines under aerobic conditions is not a wide spread metabolic activity. In this study we describe the use of Brevibacterium sp. strain VN-15, isolated from an activated sludge process of a textile company, for the sequential decolorization and detoxification of the azo dyes Reactive Yellow 107 (RY107), Reactive Black 5 (RB5), Reactive Red 198 (RR198) and Direct Blue 71 (DB71). Tyrosinase activity was observed during the biotreatment process suggesting the role of this enzyme in the decolorization and degradation process, but no-activity was observed for laccase and peroxidase. Toxicity, measured using Daphnia magna, was completely eliminated.

  2. Catabolism of volatile sulfur compounds precursors by Brevibacterium linens and Geotrichum candidum, two microorganisms of the cheese ecosystem.

    Science.gov (United States)

    Arfi, Kenza; Amárita, Felix; Spinnler, Henry-Eric; Bonnarme, Pascal

    2003-11-01

    Two Brevibacterium linens strains and the cheese-ripening yeast Geotrichum candidum were compared with regard to their ability to produce volatile sulfur compounds (VSCs) from three different precursors namely L-methionine, 4-methylthio-2-oxobutyric acid (KMBA) and 4-methylthio-2-hydroxybutyric acid (HMBA). All microorganisms were able to convert these precursors to VSCs. However, although all were able to produce VSCs from L-methionine, only G. candidum accumulated KMBA when cultivated on this amino acid, contrary to B. linens suggesting that the transamination pathway is not active in this microorganism. Conversely, a L-methionine gamma-lyase activity--which catalyses the one step L-methionine to methanethiol (MTL) degradation route--was only found in B. linens strains. Several other enzymatic activities involved in the catabolism of the precursors tested were investigated. KMBA transiently accumulated in G. candidum cultures, and was then reduced to HMBA by a KMBA dehydrogenase (KDH) activity. This activity was not detected in B. linens. Despite no HMBA dehydrogenase (HDH) was found in G. candidum, a strong HMBA oxidase (HOX) activity was measured in this microorganism. This latter activity was weakly active in B. linens. KMBA and HMBA demethiolating activities were found in all the microorganisms. Our results illustrate the metabolic diversity between cheese-ripening microorganisms of the cheese ecosystem.

  3. Improvement of L-valine production at high temperature in Brevibacterium flavum by overexpressing ilvEBNrC genes.

    Science.gov (United States)

    Hou, Xiaohu; Ge, Xiangyang; Wu, Di; Qian, He; Zhang, Weiguo

    2012-01-01

    Brevibacterium flavum ATCC14067 was engineered for L: -valine production by overexpression of different ilv genes; the ilvEBN(r)C genes from B. flavum NV128 provided the best candidate for L: -valine production. In traditional fermentation, L: -valine production reached 30.08 ± 0.92 g/L at 31°C in 72 h with a low conversion efficiency of 0.129 g/g. To further improve the L: -valine production and conversion efficiency based on the optimum temperatures of L: -valine biosynthesis enzymes (above 35°C) and the thermotolerance of B. flavum, the fermentation temperature was increased to 34, 37, and 40°C. As a result, higher metabolic rate and L: -valine biosynthesis enzymes activity were obtained at high temperature, and the maximum L: -valine production, conversion efficiency, and specific L: -valine production rate reached 38.08 ± 1.32 g/L, 0.241 g/g, and 0.133 g g(-1) h(-1), respectively, at 37°C in 48 h fermentation. The strategy for enhancing L: -valine production by overexpression of key enzymes in thermotolerant strains may provide an alternative approach to enhance branched-chain amino acids production with other strains.

  4. 3-(2-hydroxyphenyl)catechol as substrate for proximal meta ring cleavage in dibenzofuran degradation by Brevibacterium sp. strain DPO 1361

    Energy Technology Data Exchange (ETDEWEB)

    Strubel, V.; Engesser, K.H.; Fischer, P.; Knackmuss, H.J. (Univ. Stuttgart (West Germany))

    1991-03-01

    Dibenzofuran (DBF) has been used in some recent studies as a model compound for investigating the microbial degradation of cyclic biaryl ethers. Public attention has focused on this class of compounds, since it comprises some of the most pernicious and persistent molecules, such as TCDD (2,3,7,8-tetrachlorodibenzo-p-dioxin). For DBF, the most simple cyclic biaryl ether, a novel degradation mechanism involving angular dioxygenation has been described with 3-(2-hydroxyphenyl)catechol (HPC) as a central intermediate. Definite proof for this mechanism is presented in this paper, and the total degradation of DBF by Brevibacterium is described.

  5. Rhizospheric bacterial strain Brevibacterium casei MH8a colonizes plant tissues and enhances Cd, Zn, Cu phytoextraction by white mustard

    Directory of Open Access Journals (Sweden)

    Tomasz ePłociniczak

    2016-02-01

    Full Text Available Environmental pollution by heavy metals has become a serious problem in the world. Phytoextraction, which is one of the plant-based technologies, has attracted the most attention for the bioremediation of soils polluted with these contaminants.The aim of this study was to determine whether the multiple-tolerant bacterium, Brevibacterium casei MH8a isolated from the heavy metal-contaminated rhizosphere soil of Sinapis alba L., is able to promote plant growth and enhance Cd, Zn and Cu uptake by white mustard under laboratory conditions. Additionally, the ability of the rifampicin-resistant spontaneous mutant of MH8a to colonize plant tissues and its mechanisms of plant growth promotion were also examined. In order to assess the ecological consequences of bioaugmentation on autochthonous bacteria, the phospholipid fatty acid (PLFA analysis was used. The MH8a strain exhibited the ability to produce ammonia, 1-amino-cyclopropane-1-carboxylic acid deaminase, indole 3-acetic acid and HCN but was not able to solubilize inorganic phosphate and produce siderophores. Introduction of MH8a into soil significantly increased S. alba biomass and the accumulation of Cd (208%, Zn (86% and Cu (39% in plant shoots in comparison with those grown in non-inoculated soil. Introduced into the soil, MH8a was able to enter the plant and was found in the roots and leaves of inoculated plants thus indicating its endophytic features. PLFA analysis revealed that the MH8a that was introduced into soil had a temporary influence on the structure of the autochthonous bacterial communities. The plant growth-promoting features of the MH8a strain and its ability to enhance the metal uptake by white mustard and its long-term survival in soil as well as its temporary impact on autochthonous microorganisms make the strain a suitable candidate for the promotion of plant growth and the efficiency of phytoextraction.

  6. (L)-Valine production with minimization of by-products' synthesis in Corynebacterium glutamicum and Brevibacterium flavum.

    Science.gov (United States)

    Hou, Xiaohu; Chen, Xinde; Zhang, Yue; Qian, He; Zhang, Weiguo

    2012-12-01

    Corynebacterium glutamicum ATCC13032 and Brevibacterium flavum JV16 were engineered for L-valine production by over-expressing ilvEBN ( r ) C genes at 31 °C in 72 h fermentation. Different strategies were carried out to reduce the by-products' accumulation in L-valine fermentation and also to increase the availability of precursor for L-valine biosynthesis. The native promoter of ilvA of C. glutamicum was replaced with a weak promoter MPilvA (P-ilvAM1CG) to reduce the biosynthetic rate of L-isoleucine. Effect of different relative dissolved oxygen on L-valine production and by-products' formation was recorded, indicating that 15 % saturation may be the most appropriate relative dissolved oxygen for L-valine fermentation with almost no L-lactic acid and L-glutamate formed. To minimize L-alanine accumulation, alaT and/or avtA was inactivated in C. glutamicum and B. flavum, respectively. Compared to high concentration of L-alanine accumulated by alaT inactivated strains harboring ilvEBN ( r ) C genes, L-alanine concentration was reduced to 0.18 g/L by C. glutamicum ATCC13032MPilvA△avtA pDXW-8-ilvEBN ( r ) C, and 0.22 g/L by B. flavum JV16avtA::Cm pDXW-8-ilvEBN ( r ) C. Meanwhile, L-valine production and conversion efficiency were enhanced to 31.15 g/L and 0.173 g/g by C. glutamicum ATCC13032MPilvA△avtA pDXW-8-ilvEBN ( r ) C, 38.82 g/L and 0.252 g/g by B. flavum JV16avtA::Cm pDXW-8-ilvEBN ( r ) C. This study provides combined strategies to improve L-valine yield by minimization of by-products' production.

  7. Effect of duration of osmotic downshock and coexisting glutamate on survival and uptake of ectoine in halotolerant Brevibacterium sp. JCM 6894.

    Science.gov (United States)

    Nagata, Shinichi; Wang, Chenxiang

    2006-01-01

    Halotolerant Brevibacterium sp. JCM 6894 that was subjected to an osmotic downshock (0.7 M NaCl to 0 M) was examined for its survival and uptake of ectoine in the presence of ectoine and/or carbon sources. In the presence of ectoine alone, the rates of ectoine uptake by the 1 h-downshocked cells were low and high in the absence and presence of 0.7 M NaCl, respectively, which were in parallel with the rates of cell growth. The presence of glutamate or amino acids together with ectoine exerted a stimulative effect on the survival of downshocked cells. The incubation time of the cells subjected to osmotic downshock strongly affected ectoine uptake as well as the cell growth of this strain, suggesting that the transporter of ectoine in the strain JCM 6894 was stimulated during the osmotic downshock for about 1 h. Different downshock strengths had marked effects on the rate of ectoine uptake when the downshocked cells were incubated in the presence of NaCl.

  8. Report: Bioconversion of agriculture waste to lysine with UV mutated strain of brevibacterium flavum and its biological evaluation in broiler chicks.

    Science.gov (United States)

    Tabassum, Alia; Hashmi, Abu Saeed; Masood, Faiza; Iqbal, Muhammad Aamir; Tayyab, Muhammad; Nawab, Amber; Nadeem, Asif; Sadeghi, Zahra; Mahmood, Adeel

    2015-07-01

    Lysine executes imperative structural and functional roles in body and its supplementation in diet beneficial to prevent the escalating threat of protein deficiency. The physical mutagenesis offers new fascinating avenues of research for overproduction of lysine through surplus carbohydrate containing agriculture waste especially in developing countries. The current study was aimed to investigate the potential of UV mutated strain of Brevibacterium flavum at 254 nm for lysine production. The physical and nutritional parameters were optimized and maximum lysine production was observed with molasses (4% substrate water ratio). Moreover, supplementation of culture medium with metal cations (i.e. 0.4% CaSO₄, 0.3% NaCl, 0.3% KH₂PO₄, 0.4% MgSO₄, and 0.2% (NH₄) ₂SO₄w/v) together with 0.75% v/v corn steep liquor significantly enhanced the lysine production up to 26.71 ± 0.31 g/L. Though, concentrations of urea, ammonium nitrate and yeast sludge did not exhibit any profound effect on lysine production. Biological evaluation of lysine enriched biomass in terms of weight gain and feed conversion ratio reflected non-significant difference for experimental and control (+ve) groups. Conclusively, lysine produced in the form of biomass was compatible to market lysine in its effectiveness and have potential to utilize at commercial scale.

  9. Characterization of the extremely arsenic-resistant Brevibacterium linens strain AE038-8 isolated from contaminated groundwater in Tucumán, Argentina

    Science.gov (United States)

    Maizel, Daniela; Blum, Jodi S.; Ferrero, Marcela A.; Utturkar, Sagar M.; Brown, Steven D.; Rosen, Barry P.; Oremland, Ronald S.

    2015-01-01

    Brevibacterium linens AE038-8, isolated from As-contaminated groundwater in Tucumán (Argentina), is highly resistant to arsenic oxyanions, being able to tolerate up to 1 M As(V) and 75 mM As(III) in a complex medium. Strain AE038-8 was also able to reduce As(V) to As(III) when grown in complex medium but paradoxically it could not do this in a defined minimal medium with sodium acetate and ammonium sulfate as carbon and nitrogen sources, respectively. No oxidation of As(III) to As(V) was observed under any conditions. Three copies of the ars operon comprising arsenic resistance genes were found on B. linens AE038-8 genome. In addition to the well known arsC, ACR3 andarsR, two copies of the arsO gene of unknown function were detected.

  10. Bench-scale production of acrylamide using the resting cells of Brevibacterium sp. CH2 in a fed-batch reactor.

    Science.gov (United States)

    Lee, C Y; Choi, S K; Chang, H N

    1993-11-01

    Effects of various organic acids and salts on the stabilization of nitrile hydratase were investigated. The stability of the nitrile hydratase of Brevibacterium CH2 during storage was greatly enhanced by the addition of n-butyric acid. Effects of temperature, pH, and concentrations of acrylonitrile and n-butyric acid on acrylamide production by the resting cells were also investigated. Acrylamide production per unit dry weight of the cells increased 1.33 times by the addition of 0.05% n-butyric acid. A 20% acrylamide solution was successfully produced in a bench-scale reactor (12 l) with only a trace amount of salts after 10 h of hydration reaction under optimum reaction conditions without using an isotonic substrate. The conversion yield was nearly 100%, and acrylic acid as a by-product was not produced. Final acrylamide production of 400 g g-1 cells and productivity of 20 g/(g cells l-1 x h-1) were obtained.

  11. [Microbial synthesis of deuterium labelled L-phenylalanine with different levels of isotopic enrichment by facultative methylotrophic bacterium Brevibacterium methylicum with RMP assimilation of carbon].

    Science.gov (United States)

    Mosin, O V; Shvets, V I; Skladnev, D A; Ignatov, I

    2014-01-01

    The preparative microbial synthesis of amino acids labelled with stable isotopes, including deuterium ( 2 H), suitable for biomedical applications by methylotrophic bacteria was studied using L-phenylalanine as example. This amino acid is secreted by Gram-negative aerobic facultative methylotrophic bacteria Brevibacterium methylicum, assimilating methanol via ribulose-5-monophosphate (RMP) cycle of assimilation of carbon, The data on adaptation of L-phenylalanine secreted by methylotrophic bacterium В. methylicum to the maximal concentration of deuterium in the growth medium with 98% 2 Н 2 O and 2% [ 2 Н]methanol, and biosynthesis of deuterium labelled L-phenylalanine With different levels of enrichment are presented. The strain was adapted by means of plating initial cells on firm (2% agarose) minimal growth media with an increasing gradient of 2 Н 2 O concentration from 0; 24.5; 49.0; 73.5 up to 98% 2 Н 2 O followed by subsequent selection of separate colonies stable to the action of 2 Н 2 O. These colonies were capable to produce L-phenylalanine. L-phenylalanine was extracted from growth medium by extraction with isopropanol with the subsequent crystallization in ethanol (output 0.65 g/l). The developed method of microbial synthesis allows to obtain deuterium labelled L-phenylalanine with different levels of isotopic enrichment, depending on concentration of 2 Н 2 O in growth media, from 17% (on growth medium with 24,5% 2 Н 2 O) up to 75% (on growth medium with 98% 2 Н 2 O) of deuterium in the molecule that is confirmed with the data of the electron impact (EI) mass- spectrometry analysis of methyl ethers of N-dimethylamino(naphthalene)-5-sulfochloride (dansyl) phenylalanine in these experimental conditions.

  12. 黄色短杆菌原生质体制备与再生条件的研究%Study on Protoplast Preparation and Regeneration of Brevibacterium flavum

    Institute of Scientific and Technical Information of China (English)

    祁咏春; 徐军庆; 高艳华; 李峰; 袁建国

    2013-01-01

    Objective To determine the optimal conditions of protoplast preparation and regeneration of Brevibacterium flavum which produces glutamine highly.Methods we used lysozyme to hydrolyze Brevibacterium flavum which had been pretreated with penicillin and glycine,then researched the effects of cell age,concentration and pretreatment time of penicillin and glycine,enzyme concentration,enzymolysis time,enzymolysis temperature on protoplast preparation and regeneration.Results The optimal conditions of protoplast preparation and regeneration were as follows:pretreating Brevibacteriumflavum at the early time of exponential phase,the optimum concentration of penicillin of 0.4 u/mL,2 % glycine,preconditioning time of 2 h,enzyme concentration of 1 mg/mL,enzymolysis time of 12 h,enzymolysis temperature of 37 ℃.Conclusion Under the optimal conditions,the protoplast formation rate can be 99.71%,the regeneration rate can be 16.52 %.%目的 研究高产谷氨酰胺的黄色短杆菌原生质体制备和再生的最佳条件.方法 用青霉素和甘氨酸预处理黄色短杆菌后,用溶菌酶酶解,研究菌龄、青霉素和甘氨酸预处理浓度及时间、酶浓度、酶解时间、酶解温度等条件对原生质体制备和再生的影响.结果 原生质体制备和再生的最佳条件为:预处理处于对数生长早期的黄色短杆菌,青霉素最适浓度0.4 u/mL,甘氨酸浓度2%,预处理时间2h,酶浓度1 mg/mL,酶解时间12h,酶解温度37℃.结论 在最佳条件下原生质体形成率达99.71%,再生率达16.52%.

  13. Using of Facultative Methylotrophic Bacterium Brevibacterium Methylicum В-5652 With RMP-cycle of Carbon Assimilation for Microbiological Synthesis of [2H]phenylalanine With Different Levels of Deuterium Enrichment

    Directory of Open Access Journals (Sweden)

    Oleg Mosin

    2014-03-01

    Full Text Available With using of a strain of of L-phenylalanine secreted Gram-positive aerobic facultative methylotrophic bacteria Brevibacterium methylicum В-5652, assimilating methanol via ribulose-5-monophosphate (RMP cycle of carbon assimilation it was carried out the preparative microbiological synthesis of phenylalanine and metabolically related amino acids (alanine, valine, leucine/isoleucine in the amount of 5–6 mmol/l, labelled with deuterium (2H. The data on adaptation of L-phenylalanine secreted methylotrophic bacterium В. methylicum to the maximal concentration of deuterium in minimal growth medium M9 with 98 % 2Н2O and 2 % [2Н]methanol, and data on biosynthesis of deuterium labelled L-phenylalanine with different levels of enrichment are submitted. The developed method for biosynthesis allows to obtain [2Н]phenylalanine with different levels of isotopic enrichment, depending on 2Н2O concentration in growth media M9, from 17 % (2 deuterium atoms (on growth medium with 24,5 % 2Н2О right up to 75 % (6 deuterium atoms (on growth medium with 98 % 2Н2О with introduction of deuterium to benzyl С6Н5СН2-fragment of molecule that is confirmed with the data of the electron impact (EI mass-spectrometry analysis of methyl ethers of N-dimethylamino(naphthalene-5-sulfochloride (dansyl derivatives of [2Н]phenylalanine, isolated from the liquid culture after its separation by RP HPLC

  14. Cloning of Phosphoserine Aminotransferase (SerB) Gene of Escherichia coli and Expression in Brevibacterium flavum%大肠杆菌SerB基因的克隆及其在黄色短杆菌中的表达

    Institute of Scientific and Technical Information of China (English)

    殷丽霞; 崔春生; 简子健; 谭慧林; 包慧芳

    2006-01-01

    磷酸丝氨酸转氨酶(Phosphoserine aminotransferase,SerB)是L-丝氨酸生物合成中的关键酶,应用PCR技术从大肠杆菌JM109(E.Coli JM109)中扩增出磷酸丝氨酸转氨酶基因,将其与表达载体pEC 7连接.通过电转化方法,将重组质粒转入黄色短杆菌(Brevibacterium flavum C-11,BfC-11)中,经酶活检测和摇瓶发酵培养,含有重组表达质粒的BfC-11B的磷酸丝氨酸转氨酶的活力和L-丝氨酸产率均比原宿主菌BfC-11有所提高,为构建L-丝氨酸高产基因工程菌的研究奠定了基础.

  15. Optimization of Cholesterol-Induced Cholesterol Oxidase Production by Brevibacterium sp.%胆固醇诱导甾短杆菌发酵产胆固醇氧化酶能力的研究

    Institute of Scientific and Technical Information of China (English)

    傅裕; 丁晓雯; 蒋丽施; 李凯; 罗金凤; 任美燕

    2012-01-01

    In this study,Brevibacterium sp.was cultured in a fermentation medium supplemented with cholesterol to enhance the production of cholesterol oxidase.Through one-factor-at-a-time analysis,three experimental conditions including cholesterol and Tween-80 concentration in the fermentation medium and ultrasonic power(for promoting the release of intracellular cholesterol oxidase) were found to significantly influence the activity of crude cholesterol oxidase solution.The optimal cholesterol and Tween-80 concentration as well as ultrasonic power and treatment time were 3.30 g/L,3.72 mL/L,80 W and 20 min,respectively,as optimized using Box-Behnken experimental design and response surface methodology.The resulting cholesterol oxidase activity was 731.967 U/L,which was increased by 1.17-fold when compared with that obtained in the absence of cholesterol.%利用胆固醇诱导甾短杆菌发酵来提高胆固醇氧化酶产量;通过对单因素的研究,选取影响比较显著的3个因素:胆固醇质量浓度、吐温-80添加量、超声波功率,并利用Box-Behnken试验设计和响应曲面分析法进一步研究得到结果:甾短杆菌产酶的最佳条件是当超声时间为20min时,胆固醇质量浓度为3.30g/L、吐温-80添加量为3.72mL/L、超声波功率为80W,在此条件下测得的胆固醇氧化酶产量为731.967U/L。比未使用胆固醇诱导产酶时,酶产量提高了1.17倍。

  16. NH4+浓度对黄色短杆菌XV0505发酵生产L-缬氨酸的影响%Effect of NH4+concentration on L-valine fermentation by Brevibacterium flavum XV0505

    Institute of Scientific and Technical Information of China (English)

    冯宁; 白亚磊; 徐庆阳; 谢希贤; 陈宁

    2011-01-01

    以L-缬氨酸(L-Val)生产菌黄色短杆菌XV0505为供试菌株,以(NH4)2SO4为唯一添加N源,考察不同NH4+浓度对发酵过程中菌体干质量、L-Val产量和葡萄糖消耗速率以及菌体内代谢流量的影响.研究表明:NH4+浓度过高或不足都会影响发酵水平,降低L-Val的产量.合适的初始NH4+浓度为225 mmol/L,产酸期NH4+维持浓度为35mmol/L时,有利菌体产酸.在此NH4+浓度下,在30L发酵罐发酵60h,发酵液中菌体生物量和L-Val质量浓度分别可达22.35和59.12g/L.%The ammonium sulfate was selected as the only feeding nitrogen source in the L-valine fermentation process by Brevibacterium flavum XV0505. Effects of different N H4+ concentrations on biomass,yield of L-valine,glucose consumption rate and the metabolic flux were studied in a 30 L fermentor. Results showed that excessive or insufficient concentrations of NH4+ would adversely affect the yield of L-valine and bacterial growth. Therefore,the appropriate additive dosage of NH4+ (225 mmol/l) was determined,and L-valine production was increased by keeping low NH4+ concentration(35 mmol/L) in the synthesis period of L-valine. With the optimum additional dosage of NH4+ , the yields of L-valine and DCW were up to 59. 12 and 22. 35 g/L (60 h) in the 30 L fermentor.

  17. 溶氧控制对黄色短杆菌YILW合成L-异亮氨酸的影响%Effect of Dissolved Oxygen Control on L-isoleucine Synthesis by Brevibacterium flavum YIL W

    Institute of Scientific and Technical Information of China (English)

    白亚磊; 徐庆阳; 谢希贤; 陈宁

    2011-01-01

    The condition of dissolved oxygen of L-isoleucine synthesis in Brevibacterium flavum YILW was explored,and the metabolic networks and metabolic flux balance model were constructed. The fermentation processes were studied on the condition of different dissolved oxygen in 30 L fermenter. The results show that high dissolved oxygen leads to bacterium growth. Higher production ratio of L-isoleucine maintains a long time under the condition of 15% dissolved oxygen. Thus the grading-controlling mode of dissolved oxygen was proposed: 25% dissolved oxygen concentration in the cell growth phase and 15% dissolved oxygen concentration in the phase of acid stable. Under this strategy,the yield of L-isoleucine is 31.8 g/L in 30 L fermenter in 60 h,and the conversion of sugar to acid is up to 18.3%. The vice acid is reduced significantly such as lactic, alanine. The results was demonstrated by using the method of metabolic flux analysis ,providing a theoretical basis for the in-depth understanding from the perspective of the amount of dissolved oxygen on L-isoleucine fermentation , and providing a theoretical guidance for further optimization of L-isoleucine fermentation condition of dissolved oxygen.%对黄色短杆菌YILW合成L-异亮氨酸的发酵溶氧条件进行了探索,构建了该菌合成上L-异亮氨酸的代谢网络和代谢流平衡模型.在30 L发酵罐中考察了不同溶氧浓度下L-异亮氨酸发酵过程.研究结果表明:高溶氧浓度有利于菌体生长,15%溶氧浓度下产酸速率高且维持的时间长,有利于L-异亮氨酸的积累.为此提出了分段控氧模式:在菌体生长期,溶氧浓度控制为25%;在产酸稳定期,溶氧浓度控制为15%.在此溶氧控制模式下,在30 L发酵罐上补料分批发酵60 h.L-异亮氨酸产量可达31.8 g/L,糖酸转化率可达18.3%,且乳酸、丙氨酸等副酸明显减少.对此结果运用代谢流分析的方法进行论证,旨在从量的角度理解溶氧对L-异亮氨酸合

  18. The Effect of Nitrogen Sources and Its Additional Strategies on L-valine Fermentation by Brevibacterium flavum XV0505%氮源及其补加策略对L-缬氨酸发酵的影响

    Institute of Scientific and Technical Information of China (English)

    冯宁; 白亚磊; 徐庆阳; 谢希贤; 陈宁

    2011-01-01

    通过分析黄色短杆菌xv0505发酵生产L-缬氨酸的过程,得知在菌体生长期和快速产酸期氮源对L-缬氨酸发酵的影响不同.以黄色短杆菌XV0505为供试菌株,研究了不同氮源种类及不同氮源浓度对L-缬氨酸发酵过程的影响,选定了以豆饼水解液和硫酸铵为氮源,并确定了合适的初始氮源浓度.在初始氮源浓度相同的情况下,考察了间歇流加补氮策略、恒氮源浓度补氮策略和幂函数流加补氮策略对L-缬氨酸发酵的影响,研究发现,幂指数补氮策略可减少频繁的取样及铵浓度检测,在缺乏在线监测系统和反馈自控系统的情况下,将发酵体系中氮源浓度维持在合适值,既可适度促进菌体生长,又可使L-缬氨酸的产量得到进一步提高.在最优的氮源添加策略下,在30 L发酵罐发酵60 h,发酵液中L-缬氨酸可达63.17 g/L,糖酸转化率24.69%.%By analyzing the L-valine fermentation process by Brevibacterium flavum XV0505, one of important factors influenced on the bacterial productivity and L-valine yield is nitrogen source and its additional strategies. The effect of nitrogen sources on the fermentation of L-valine was studied by adding different nitrogen sources with different concentrations. Therefore, soybean hydrolysates and ammonium sulfate were selected as the appropriate nitrogen source, and the best L-valine yield was obtained with the medium supplemented low initial concentration of 225 mmol/L. In the case of the same initial nitrogen concentration, the effects of three nitrogen feeding strategies (intermittent nitrogen feeding,constant concentration feeding and power function feeding) on biomass, yield of L-valine,concentration of byproduct and conversion rate were studied in the 30L fermentor. The result showed that the concentration and the feed rate of nitrogen source were effectively and timely manipulated by power function feeding, while lacking of online monitoring and feedback

  19. 黄色短杆菌 ilvN 基因定点突变和 ilvBN、ilvC 串联表达对L-缬氨酸产量的影响%Effects of Brevibacterium flavum with directed mutagenesis of ilvN and co-expression of ilvBNC cluster on L-valine production

    Institute of Scientific and Technical Information of China (English)

    曾邦定; 黄钦耿; 梁玲; 郭小雷; 王明兹; 施巧琴; 吴松刚

    2016-01-01

    由 ilvBN、ilvC 基因编码的乙酰羟酸合成酶(AHAS)和乙酰羟酸异构还原酶(AHAIR)是 L-缬氨酸合成途径的两个关键酶。本实验以黄色短杆菌 Brevibacterium flavum MD515为出发菌株,通过 PCR 技术扩增其 ilvBN和 ilvC 基因,对调节亚基 ilvN 进行定点突变,获得抗反馈抑制突变型编码基因 ilvBNrC;然后将其插入穿梭表达载体 pZ8-1中,构建串联表达质粒 pZ8-1-ilvBNrC 并转化出发菌株,筛选获得工程菌株 B.flavum MD515/pZ8-1-ilvBNrC。摇瓶发酵该工程菌株 L-缬氨酸产量达29.5 g·L−1,较出发菌株提高27.7%,同时生长速度和生物量也比出发菌株有所提高,丙氨酸含量降低,L-亮氨酸及 L-异亮氨酸含量提高。在30 L 发酵罐连续补料发酵60 h 后 L-缬氨酸产量达61.7 g·L−1,糖酸转化率为39.2%。菌株 MD515/pZ8-1-ilvBNrC 发酵液透光率较出发菌株高且蛋白含量低,这些特性有利于发酵液后期的分离提取。%Acetohydroxy acid synthase (AHAS) and acetohydroxy acid isomeroreductase (AHAIR) encoded by ilvBN and ilvC are two key enzymes which play important roles in the biosynthetic pathway of L-valine. Brevibacterium flavum MD515 was used as the origin strain and site-specific mutagenesis was performed in its ilvN gene which coded for the regulatory subunit of AHAS, resulting in the obtainment of an anti-feedback inhibition gene, named ilvBN'C. Then, the ilvBNrC gene was ligased to plasmid pZ8-1 for construction of the recombinant plasmid pZ8-1-ilvBNrC, which was subsequently transfored into B. flavum MD515. With this method, the targeted transformant B. flavum MD515/pZ8-1-ilvBNrC showed better L-valine producing capacity of 29.5 g·L−1, 27.7% increase than that of original strain when it was cultured in 250 ml shake flasks. Meanwhile, the yield of leucine and isoleucine also increased while the alanine decreased. The biomass and growth rate were also increased. Moreover

  20. Brevibacterium oceanic sp. nov., isolated from deep-sea sediment of the Chagos Trench, Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Bhadra, B.; Raghukumar, C.; Pindi, P.K.; Shivaji, S.

    Two bacterial strains, designated BBH5 and BBH7 sup(T), were isolated from a deep-sea sediment sample collected from the Chagos Trench of the Indian Ocean (11 degrees 6 minutes S 72 degrees 31 minutes E). Based on their 16S rRNA gene sequence...

  1. Effect of oxidative stress induced by Brevibacterium sp. BS01 on a HAB causing species--Alexandrium tamarense.

    Directory of Open Access Journals (Sweden)

    Huajun Zhang

    Full Text Available Harmful algal blooms occur all over the world, destroying aquatic ecosystems and threatening other organisms. The culture supernatant of the marine algicidal actinomycete BS01 was able to lysis dinoflagellate Alexandrium tamarense ATGD98-006. Physiological and biochemical responses to oxidative stress in A. tamarense were investigated to elucidate the mechanism involved in BS01 inhibition of algal growth. Transmission electron microscope analysis revealed that there were some chloroplast abnormalities in response to BS01 supernatant. The decrease in cellular-soluble protein content suggested that cell growth was greatly inhibited at high concentration of BS01 supernatant. The increase in the levels of reactive oxygen species (ROS and malondialdehyde contents following exposure to BS01 supernatant indicated that algal cells suffered from oxidative damage. The content of pigment was significantly decreased after 12 h treatment, which indicated that the accumulation of ROS destroyed pigment synthesis. Moreover, the decrease of Fv/Fm ratio suggested that in the photosynthetic system, the dominant sites producing ROS were destroyed by the supernatant of the BS01 culture. The activities of the antioxidant enzymes including superoxide dismutase and peroxidase increased in a short time and decreased slightly with increasing exposure time. A real-time PCR assay showed changes in the transcript abundances of two photosynthetic genes, psbA and psbD. The results showed that BS01 supernatant reduced the expression of the psbA gene after 2 h exposure, but the expression of the psbD gene was increased at concentrations of 1.0 and 1.5%. Our results demonstrated that the expression of the psbA gene was inhibited by the BS01 supernatant, which might block the electron transport chain, significantly enhancing ROS level and excess activity of the antioxidant system. The accumulation of ROS destoryed pigment synthesis and membrane integrity, and inhibited or ultimately killed the algal cells.

  2. Comparison of two poultry litter qPCR assays targeting the 16S rRNA gene of Brevibacterium sp

    Science.gov (United States)

    Chicken feces are vectors of human pathogens and are also important sources of fecal pollution in environmental waters. Consequently, methods that can detect chicken fecal pollution are needed in public health and environmental monitoring studies. In this study, we compared a pre...

  3. Genome analysis shows Bacillus axarquiensis is not a later heterotypic synonym of Bacillus mojavensis; Reclassification of Bacillus malacitensis and Brevibacterium halotolerans as heterotypic synonyms of Bacillus axarquiensis

    Science.gov (United States)

    Bacillus axarquiensis and Bacillus malacitensis were previously reported to be later heterotypic synonyms of Bacillus mojavensis, based primarily on DNA-DNA relatedness values. We have sequenced draft genomes of Bacillus axarquiensis NRRL B-41617**T and Bacillus malacitensis NRRL B-41618**T. Compara...

  4. GENE 16S RRNA SEQUENCE PHYLOGENETIC ANALYSIS OF LYSINE PRODUCERS STRAINS

    Directory of Open Access Journals (Sweden)

    G. S. Andriiash

    2014-12-01

    Full Text Available The phylogenetic relationships of strainsproducers of essential amino acids of aspartate family Brevibacterium sp. UCM Ac-674 (Brevibacterium sp. 90, Brevibacterium sp. IMV Ac-5004 (Brevibacterium sp. 90H, Brevibacterium sp. UCM Ac-675 (Brevibacterium sp. E531, mutant strain Brevibacterium sp. IMV B-7447 from the «Collections strains and lines of plants for food and agricultural biotechnology SO “Institute for Food Biotechnology and Genomics” of National Academy of Sciences of Ukraine were investigated. The affiliation strain Brevibacterium sp. IMV B-7447 to the genus Brevibacterium within the sequences of the genes based on 16S rRNA was confirmed. The dendogram of phylogenetic relationships of studied strains and related strains Brevibacterium from database GenBank was constructed. It was shown that by the criterion of homology gene sequences based on 16S rRNA the investigated strains-producers belong to three phylogenetic groups. It was established that the mutant strain Brevibacterium sp. ІMV B-7447 has no analogues in the database GenBank.

  5. Autoinducer-2 activity produced by bacteria found in smear of surface ripened cheeses

    DEFF Research Database (Denmark)

    Gori, Klaus; Moslehi Jenabian, Saloomeh; Purrotti, Micol

    2011-01-01

    -2) activity using the Vibrio harveyi (BB170) bioluminescence assay. In contrast, Brevibacterium casei and Brevibacterium linens strains were not found to have AI-2 activity. When exposed to low pH and high NaCl concentrations, AI-2 activities increased between 5.0 and 11.6× for C. casei 44701, M...

  6. Behaviour of marine oil-degrading bacterial populations in a continuous culture system

    Digital Repository Service at National Institute of Oceanography (India)

    Mohandass, C.; David, J.J.; Nair, S.; LokaBharathi, P.A.; Chandramohan, D.

    In pursuit of developing an oil-degrading microbial consortium, we used the principle of "plasmid assisted molecular breeding" (PAMB) in a continuous culture system. Three marine bacteria, Pseudomonas putida, Brevibacterium epidermidis...

  7. Diversity of l-Ieucine catabolism in various microorganisms involved in dairy fermentations, and identification on the rate-controlling step in the formation of the potent flavour component 3-methylbutanal.

    NARCIS (Netherlands)

    Smit, B.A.; Engels, W.J.M.; Wouters, J.T.M.; Smit, G.

    2004-01-01

    Various microorganisms, belonging to the genera Lactococcus, Lactobacillus, Streptococcus, Leuconostoc, Bifidobacterium, Propionibacterium, Brevibacterium, Corynebacterium and Arthrobacter, used in dairy fermentations such as cheese making, were analysed for their potential to convert leucine into f

  8. Detoxification of toxic heavy metals by marine bacteria highly resistant to mercury

    Digital Repository Service at National Institute of Oceanography (India)

    De, J.; Ramaiah, N.; Vardanyan, L.

    isolate), Pseudomonas aeruginosa (one isolate), and Brevibacterium iodinium (one isolate). The mechanisms of heavy metal detoxification were through volatilization (for Hg), putative entrapment in the extracellular polymeric substance (for Hg, Cd and Pb...

  9. Bioremediation of toxic substances by mercury resistant marine bacteria

    Digital Repository Service at National Institute of Oceanography (India)

    De, J.; Sarkar, A.; Ramaiah, N.

    emission spectrometry (ICP-AES). Similarly, CH07, S3 (Bacillus pumilus) and GP13 (Brevibacterium iodinium), were grown in the presence of Pb (maximum concentration of 100 ppm) and removal of Pb from the medium was estimated following standard method.... Results: Bacterial isolates: Seven of the thirteen (54%) of the MRB were identified as Alcaligenes faecalis, four (30%) were identified as Bacillus pumilus and there was one each of Pseudomonas aeruginosa, and Brevibacterium iodinium. The isolates...

  10. COLONIZATION OF VIGNA RADIATA ROOTS BY CHROMIUM RESISTANT BACTERIAL STRAINS OF OCHROBACTRUM INTERMEDIUM, BACILLUS CEREUS AND BREVIBA CTERIUM SP.

    Institute of Scientific and Technical Information of China (English)

    MUHAMMAD Faisal; SHAHIDA Hasnain

    2005-01-01

    The present study deals with colonization potential of plant growth promoting bacterial strains ( Ochrobactrum intermedium, Bacillus cereus and Brevibacterium sp. ) on Vigna radiata roots. The roots were heavily colonized with O. intermedium and B. cereus as compared to Brevibacterium sp. O. intermedium mainly colonized rhizoplane while B. cereus occurred both on the rhizoplane and near root zone. O. intermedium and B. cereus were found to be present both on the rhizoplane and near root zone, while Brevibacterium only in the rhizosphere in the form of groups. The cells of B. cereus were found more in the sites where root exudates were existed. From the above results it was observed that the number of O. intermedium cells were large at root exudate site. Fig 2, Tab 1, Ref 15

  11. A comparative study of the anti-listerial activity of smear bacteria

    DEFF Research Database (Denmark)

    Gori, Klaus; Mortensen, Christina; Jespersen, Lene

    2010-01-01

    Cell-free supernatants from Staphylococcus epidermidis, Staphylococcus warneri and Brevibacterium linens were found to possess anti-listerial activities. Anti-listerial activities were increased during exponential growth phase and reached a maximum during stationary growth phase. S. epidermidis (...... to bacteriocin production. The bacteriocins were found to be relatively heat stable and had a molecular mass higher than 30 kDa....

  12. Influence of addition of plasmin or mastitic milk to cheesemilk on quality of smear-ripened cheese

    OpenAIRE

    O'Farrell, Ian P.; Sheehan, Jeremiah J.; Martin G. Wilkinson; Harrington, Dermot; Kelly, Alan L.

    2002-01-01

    peer-reviewed Smear-ripened cheese varieties are characterised by the growth of a smear culture, containing predominantly Brevibacterium linens, on the cheese surface during ripening. In such cheese, considerable zonal differences in biochemistry of ripening exist, due to moisture loss from, and growth and metabolic activity of smear microflora at, the cheese surface. In this study, the effects of adding exogenous plasmin or small amounts of mastitic milk to good quality milk o...

  13. Bacterial Reduction of Toxic Cr(Ⅵ)into Cr(Ⅲ)%利用细菌还原有毒Cr(Ⅵ)为Cr(Ⅲ)

    Institute of Scientific and Technical Information of China (English)

    Muhammad Faisal; Shahida Hasnain

    2004-01-01

    Two chromium-resistant bacterial strains CrT-1 and CrT-13,which can tolerate K2 CrO4 up to 40 mg·mL-1 on nutrient agar,25 mg·mL-1 K2 CrO4 in nutrient broth,and up to 10 mg·mL-1 in acetate-minimal media,were used in this study.On the basis of 16S rRNA,strain CrT-1 was identified as Ochrobactrum intermedium and CrT-13 as Brevibacterium sp..Uptake of chromate was greater in living cells than in heat-killed cells.Ochrobactrum intermedium CrT-1 reduced 73% and 41% of Cr(Ⅵ)while Brevibacterium CrT-13 reduced 62% and 48% Cr(Ⅵ) at an initial chromate concentration of 750,and 1500 μg·mL-1,after 96 hours with an inoculum size of 9.6×107 cells·mL-1.Different heavy metals at low concentrations did not affect the reduction potential of the strains significantly.Ochrobactrum intermedium CrT-1 reduced 84% and 65% while Brevibacterium CrT-13 reduced 60% and 44% of Cr(Ⅵ)at an initial Cr(Ⅵ)concentration of 250 and 500 μg·mL-1,espectively,in an industrial effluent sample.

  14. Structural Basis for Substrate and Oxygen Activation in Homoprotocatechuate 2,3-Dioxygenase: Roles of Conserved Active Site Histidine-200

    OpenAIRE

    Kovaleva, Elena G.; Rogers, Melanie S.; Lipscomb, John D.

    2015-01-01

    Kinetic and spectroscopic studies have shown that the conserved active site residue His200 of the extradiol ring-cleaving homoprotocatechuate 2,3-dioxygenase (FeHPCD) from Brevibacterium fuscum is critical for efficient catalysis. The roles played by this residue are probed here by analysis of the steady state kinetics, pH dependence, and X-ray crystal structures of the FeHPCD position 200 variants His200Asn, His200Gln, and His200Glu alone and in complex with three catecholic substrates (homo...

  15. 1株湿地稀有放线菌的多相分类鉴定%Polyphasic Taxonomy of a Rare Marine Actinomycetes

    Institute of Scientific and Technical Information of China (English)

    唐树戈; 张柳; 于基成; 刘秋; 齐小辉

    2014-01-01

    Strain S402003 was isolated from marine sediment collected from Yalu River in Dandong, Liaoning Province. Based on the polyphasic studies, including the morphology, physiological and biochemical characteristics, chemotaxonomy and 16S rRNA gene sequence analysis, the results showed that strain S402003 had lipase activity and was capable to reduce nitrate, belongs to the mild salt-tolerant and basophilic bacteria. It was primarily identified as Brevibacterium linens with the similarity 98.834%.%从鸭绿江滨海湿地样品中分离得到1株稀有海洋放线菌S402003,通过形态观察、培养特征、生理生化特征、化学组分鉴定以及16S rRNA基因序列分析对其进行多相分类鉴定。结果表明:该菌株具有脂酶活性,能还原硝酸盐,属于轻度耐盐、嗜碱菌。该菌株属于Brevibacterium linens,相似性为98.834%。

  16. Molecular Detection and Sensitivity to Antibiotics and Bacteriocins of Pathogens Isolated from Bovine Mastitis in Family Dairy Herds of Central Mexico

    Science.gov (United States)

    León-Galván, Ma. Fabiola; Barboza-Corona, José E.; Lechuga-Arana, A. Arianna; Valencia-Posadas, Mauricio; Aguayo, Daniel D.; Cedillo-Pelaez, Carlos; Martínez-Ortega, Erika A.; Gutierrez-Chavez, Abner J.

    2015-01-01

    Thirty-two farms (n = 535 cows) located in the state of Guanajuato, Mexico, were sampled. Pathogens from bovine subclinical mastitis (SCM) and clinical mastitis (CLM) were identified by 16S rDNA and the sensitivity to both antibiotics and bacteriocins of Bacillus thuringiensis was tested. Forty-six milk samples were selected for their positive California Mastitis Test (CMT) (≥3) and any abnormality in the udder or milk. The frequency of SCM and CLM was 39.1% and 9.3%, respectively. Averages for test day milk yield (MY), lactation number (LN), herd size (HS), and number of days in milk (DM) were 20.6 kg, 2.8 lactations, 16.7 animals, and 164.1 days, respectively. MY was dependent on dairy herd (DH), LN, HS, and DM (P < 0.01), and correlations between udder quarters from the CMT were around 0.49 (P < 0.01). Coagulase-negative staphylococci were mainly identified, as well as Staphylococcus aureus, Streptococcus uberis, Brevibacterium stationis, B. conglomeratum, and Staphylococcus agnetis. Bacterial isolates were resistant to penicillin, clindamycin, ampicillin, and cefotaxime. Bacteriocins synthesized by Bacillus thuringiensis inhibited the growth of multiantibiotic resistance bacteria such as S. agnetis, S. equorum, Streptococcus uberis, Brevibacterium stationis, and Brachybacterium conglomeratum, but they were not active against S. sciuri, a microorganism that showed an 84% resistance to antibiotics tested in this study. PMID:25815326

  17. Halotolerant bacteria in the São Paulo Zoo composting process and their hydrolases and bioproducts

    Directory of Open Access Journals (Sweden)

    Lilian C.G. Oliveira

    2015-06-01

    Full Text Available Halophilic microorganisms are able to grow in the presence of salt and are also excellent source of enzymes and biotechnological products, such as exopolysaccharides (EPSs and polyhydroxyalkanoates (PHAs. Salt-tolerant bacteria were screened in the Organic Composting Production Unit (OCPU of São Paulo Zoological Park Foundation, which processes 4 ton/day of organic residues including plant matter from the Atlantic Rain Forest, animal manure and carcasses and mud from water treatment. Among the screened microorganisms, eight halotolerant bacteria grew at NaCl concentrations up to 4 M. These cultures were classified based on phylogenetic characteristics and comparative partial 16S rRNA gene sequence analysis as belonging to the genera Staphylococcus, Bacillus and Brevibacterium. The results of this study describe the ability of these halotolerant bacteria to produce some classes of hydrolases, namely, lipases, proteases, amylases and cellulases, and biopolymers. The strain characterized as of Brevibacterium avium presented cellulase and amylase activities up to 4 M NaCl and also produced EPSs and PHAs. These results indicate the biotechnological potential of certain microorganisms recovered from the composting process, including halotolerant species, which have the ability to produce enzymes and biopolymers, offering new perspectives for environmental and industrial applications.

  18. Molecular Detection and Sensitivity to Antibiotics and Bacteriocins of Pathogens Isolated from Bovine Mastitis in Family Dairy Herds of Central Mexico

    Directory of Open Access Journals (Sweden)

    Ma. Fabiola León-Galván

    2015-01-01

    Full Text Available Thirty-two farms (n=535 cows located in the state of Guanajuato, Mexico, were sampled. Pathogens from bovine subclinical mastitis (SCM and clinical mastitis (CLM were identified by 16S rDNA and the sensitivity to both antibiotics and bacteriocins of Bacillus thuringiensis was tested. Forty-six milk samples were selected for their positive California Mastitis Test (CMT (≥3 and any abnormality in the udder or milk. The frequency of SCM and CLM was 39.1% and 9.3%, respectively. Averages for test day milk yield (MY, lactation number (LN, herd size (HS, and number of days in milk (DM were 20.6 kg, 2.8 lactations, 16.7 animals, and 164.1 days, respectively. MY was dependent on dairy herd (DH, LN, HS, and DM P<0.01, and correlations between udder quarters from the CMT were around 0.49 P<0.01. Coagulase-negative staphylococci were mainly identified, as well as Staphylococcus aureus, Streptococcus uberis, Brevibacterium stationis, B. conglomeratum, and Staphylococcus agnetis. Bacterial isolates were resistant to penicillin, clindamycin, ampicillin, and cefotaxime. Bacteriocins synthesized by Bacillus thuringiensis inhibited the growth of multiantibiotic resistance bacteria such as S. agnetis, S. equorum, Streptococcus uberis, Brevibacterium stationis, and Brachybacterium conglomeratum, but they were not active against S. sciuri, a microorganism that showed an 84% resistance to antibiotics tested in this study.

  19. Identification and characterisation of potential biofertilizer bacterial strains

    Science.gov (United States)

    Karagöz, Kenan; Kotan, Recep; Dadaşoǧlu, Fatih; Dadaşoǧlu, Esin

    2016-04-01

    In this study we aimed that isolation, identification and characterizations of PGPR strains from rhizosphere of legume plants. 188 bacterial strains isolated from different legume plants like clover, sainfoin and vetch in Erzurum province of Turkey. These three plants are cultivated commonly in the Erzurum province. It was screen that 50 out of 188 strains can fix nitrogen and solubilize phosphate. These strains were identified via MIS (Microbial identification system). According to MIS identification results, 40 out of 50 strains were identified as Bacillus, 5 as Pseudomonas, 3 as Paenibacillus, 1 as Acinetobacter, 1 as Brevibacterium. According to classical test results, while the catalase test result of all isolates are positive, oxidase, KOH and starch hydrolysis rest results are variable.

  20. Ectoine as a natural component of food: detection in red smear cheeses.

    Science.gov (United States)

    Klein, Julia; Schwarz, Thomas; Lentzen, Georg

    2007-11-01

    Ectoine is a compatible solute accumulated in halophilic bacteria in response to high salt concentrations and offers protection from osmotic stress. The occurrence of compatible solutes is widespread among bacteria, yet ectoine has never been detected in foods. The use of an ectoine producing microorganism (Brevibacterium linens) in the surface ripening of red smear cheeses led to the question whether ectoine can be found in cheese. Therefore we examined samples from a variety of cheese manufacturers and different types of red smear cheeses for the presence of ectoine using HPLC and HPLC/MS analysis. Ectoine solely appears in the rind and was detected up to 178 mg/200 g red smear cheese, depending on several factors like ripening status and conditions throughout the cheese production process (e.g. salt concentrations of used brine baths).

  1. Possibility of using strain F9 (Serratia marcescens) as a bio-collector for hema-tite flotation

    Institute of Scientific and Technical Information of China (English)

    Hui-fen Yang; Tian Li; Yan-hong Chang; Hui Luo; Qiong-yao Tang

    2014-01-01

    In this study, we characterized strain F9 and evaluated the interaction between strain F9 and hematite by scanning electron micros-copy (SEM), Fourier transform infrared spectrophotometry (FTIR), zeta potential, flotation, and other methods. The results showed that strain F9 belongs to Serratia marcescens. This brevibacterium had CH2, CH3, and hydroxyl groups on its cell wall, which imparted a strong hy-drophobic and negative charge. Adsorption of strain F9 reduced the zeta potential of the hematite surface and increased the hydrophobicity of the hematite surface, thereby generating hydrophobic hematite agglomerates. At least four groups on strain F9 interacted with the hematite surface, which contributed to chemical interactions of carboxylic groups and hydrophobic association among hydrophobic hematite particles. The possible use of strain F9 as a bio-collector for hematite flotation was proved.

  2. Actinobacterial Flora in Feces of Healthy Cottontail Rabbits (Sylvilagus auduboni).

    Science.gov (United States)

    Zhang, Yu; Tan, Hongming; Deng, Qingli; Cao, Lixiang

    2015-03-01

    Most known antibiotics from bacteria are produced by Actinobacteria. However, little is known about the community structure and diversity of fecal actinobacteria from rabbit feces. To investigate the actinobacterial community structure in rabbit feces, different actinobacterial-specific primer sets were used to amplify the overlap regions of 16S rRNA genes from the same DNA. At the genus level, 12 actinobacterial genera were detected by the L and S libraries. Arthrobacter, Brachybacterium, Dietzia, Leucobacter, Microbacterium, Promicromonospora and Rhodococcus were detected by L and S libraries. The Nocardioides, Streptomyces and Williamsia were only detected by L library; the Oerskovia and Brevibacterium were only detected by S library. The results indicated that rabbit feces contain diverse nonpathogenic actinobacterial taxa and PCR primer sets could underestimate the actinobacterial diversity besides the DNA extract efficiency.

  3. Research and Analysis of Cultivate Bacteria in Captive Gibbons Faeces in the Kunming Zoo%昆明动物园圈养长臂猿粪便可培养细菌分析

    Institute of Scientific and Technical Information of China (English)

    李莲; 马国强; 刘丽; 刘安荣; 师婧; 周杰珑; 王秀艳

    2016-01-01

    It took seven captive Gibbons of Kuming Zoo as the research object,adopted a combination of tradi-tional microbiological and molecular biological methods,isolated,identified and analyzed the cultivate bacteria of fresh feces.The results showed that nine strains could identify to spicies among the 15 isolated strains of bacteria, which were belonged to Bacillus methylotrophicus,Enterococcus hirae,Brevibacterium halotolerans and Shigella flex-neri 4 species,respectively.The other six strains could identify to genus,which were belonged to the genus Neisse-ria and Escherichia coli 2 genus,respectively.Which the brevibacterium halotolerans and Escherichia coli were the dominant bacteria.%以昆明动物园7只圈养长臂猿为研究对象,通过传统微生物检测和分子生物学方法相结合,对其新鲜粪便可培养细菌进行分离、鉴定与分析。结果表明:分离得到的15株细菌中,有9株细菌可鉴定到种,分别属于甲基营养型芽孢杆菌、海氏肠球菌、耐盐短杆菌和弗氏志贺菌4个种;有6株细菌可以鉴定到属,分别属于奈瑟菌属和大肠杆菌2个属;其中优势菌为耐盐短杆菌和大肠杆菌。

  4. Effects of lipid concentration on anaerobic co-digestion of municipal biomass wastes

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Yifei, E-mail: sunif@buaa.edu.cn [School of Chemistry and Environment, Beihang University, Beijing 100191 (China); Wang, Dian; Yan, Jiao [School of Chemistry and Environment, Beihang University, Beijing 100191 (China); Qiao, Wei [College of Chemical Science and Engineering, China University of Petroleum, Beijing 102249 (China); Wang, Wei [School of Environment, Tsinghua University, Beijing 100084 (China); Zhu, Tianle [School of Chemistry and Environment, Beihang University, Beijing 100191 (China)

    2014-06-01

    Highlights: • Lipid in municipal biomass would not inhibited the anaerobic digestion process. • A lipid concentration of 65% of total VS was the inhibition concentration. • The amount of Brevibacterium decreased with the increasing of the lipid contents. • Long chain fatty acids stacked on the methanogenic bacteria and blocked the mass transfer process. - Abstract: The influence of the lipid concentration on the anaerobic co-digestion of municipal biomass waste and waste-activated sludge was assessed by biochemical methane potential (BMP) tests and by bench-scale tests in a mesophilic semi-continuous stirred tank reactor. The effect of increasing the volatile solid (VS) concentration of lipid from 0% to 75% was investigated. BMP tests showed that lipids in municipal biomass waste could enhance the methane production. The results of bench-scale tests showed that a lipids concentration of 65% of total VS was the inhibition concentration. Methane yields increased with increasing lipid concentration when lipid concentrations were below 60%, but when lipid concentration was set as 65% or higher, methane yields decreased sharply. When lipid concentrations were below 60%, the pH values were in the optimum range for the growth of methanogenic bacteria and the ratios of volatile fatty acid (VFA)/alkalinity were in the range of 0.2–0.6. When lipid concentrations exceeded 65%, the pH values were below 5.2, the reactor was acidized and the values of VFA/alkalinity rose to 2.0. The amount of Brevibacterium decreased with increasing lipid content. Long chain fatty acids stacked on the methanogenic bacteria and blocked the mass transfer process, thereby inhibiting anaerobic digestion.

  5. Biosynthesis, characterization, and antimicrobial applications of silver nanoparticles

    Directory of Open Access Journals (Sweden)

    Singh P

    2015-03-01

    Full Text Available Priyanka Singh,1 Yeon Ju Kim,2 Hina Singh,1 Chao Wang,2 Kyu Hyon Hwang,3 Mohamed El-Agamy Farh,1 Deok Chun Yang1,2 1Department of Oriental Medicinal Material and Processing, 2Graduate School of Biotechnology and Ginseng Bank, College of Life Sciences, Kyung Hee University, Yongin, 3Gyeonggi-Do Agricultural Research & Extension Services, Gyeonggi, Republic of Korea Abstract: In the present study, the strain Brevibacterium frigoritolerans DC2 was explored for the efficient and extracellular synthesis of silver nanoparticles. These biosynthesized silver nanoparticles were characterized by ultraviolet-visible spectrophotometry, which detected the formation of silver nanoparticles in the reaction mixture and showed a maximum absorbance at 420 nm. In addition, field emission transmission electron microscopy revealed the spherical shape of the nanoparticles. The dynamic light scattering results indicated the average particle size of the product was 97 nm with a 0.191 polydispersity index. Furthermore, the product was analyzed by energy dispersive X-ray spectroscopy, X-ray diffraction, and elemental mapping, which displayed the presence of elemental silver in the product. Moreover, on a medical platform, the product was checked against pathogenic microorganisms including Vibrio parahaemolyticus, Salmonella enterica, Bacillus anthracis, Bacillus cereus, Escherichia coli, and Candida albicans. The nanoparticles demonstrated antimicrobial activity against all of these pathogenic microorganisms. Additionally, the silver nanoparticles were evaluated for their combined effects with the commercial antibiotics lincomycin, oleandomycin, vancomycin, novobiocin, penicillin G, and rifampicin against these pathogenic microorganisms. These results indicated that the combination of antibiotics with biosynthesized silver nanoparticles enhanced the antimicrobial effects of antibiotics. Therefore, the current study is a demonstration of an efficient biological synthesis

  6. L-缬氨酸高产菌诱变育种的研究%Studies on the Breeding of L-Valine Hyper-Producing Mutant

    Institute of Scientific and Technical Information of China (English)

    张伟国; 钱和

    2011-01-01

    Using Brevibacterium flavum XQ-2 ( Leu1 (-ABr AHVr 2-TAr) as a starting strain for stepwise mutagenesis by diethylsulfate (DES), N-methyl-N '-nitro-soguanidine (NTG) treatment, a L-valine hyper-producing mutant XQ-8 (Leu1 (-ABhr2-TAhrAHVhr) was obtained,which could be resistant to high concentration a-amino-butyric acid (α-AB), 2-thiazole-DLalanaine (2-TA) and a-amino-β- hydroxy-valeric acid (AHV). As a result, high L-valine concentration (64~66g/L) was obtained with shaking at 31 ±1℃ for 72h in the medium containing 135g/L glucose and 50g/L (NH4)2SO4.%以黄色短杆茵(Brevibacterium flavum)L-缬氨酸产生菌XQ-2为出发菌株,经硫酸二乙酯(DES)和亚硝基胍(NTG)逐级诱变处理,氨基酸结构类似物α-氨基丁酸(α-AB)、2-噻唑丙氨酸(2-TA)和α一氨基-β-羟基戊酸(AHV)定向筛选,获得一株L-缬氨酸高产茵XQ-8(Leu1(-ABhr2-TAhrAHVht).在以135 g/L葡萄糖为碳源和50 g/L硫酸铵为氮源的培养基中摇瓶发酵72 h,产酸达64~66 g/L.

  7. 水磨年糕中微生物的分离纯化与鉴定%Purification and Identification of Microbes in Water Mill Rice Cake

    Institute of Scientific and Technical Information of China (English)

    陈挺; 娄永江; 庞林江; 王茜茜

    2015-01-01

    通过对年糕内部和表面的微生物进行分离纯化,并通过形态观察、生化测定的方法来鉴定微生物的组成,结果表明:年糕表面的微生物主要有6种细菌、3种霉菌和2种酵母菌。细菌中4种是芽孢杆菌,分别为巨大芽孢杆菌(Bacillus megaterium)、枯草芽孢杆菌(Bacillus subtilis)、蜡状芽孢杆菌(Bacillus cereus)和短芽孢杆菌(Bacillus brevis),2种是非芽孢杆菌,分别为乙酰短杆菌(Brevibacterium acetylicum)和乙酸钙不动杆菌(Acinetobacter calcoaceticus);霉菌分别为米根霉(Rhizopus oryzae)、构巢曲霉(Aspergillus nidulans)和米曲霉(As⁃pergillus oryzae);酵母菌分别为茁芽丝孢酵母(Trichosporon pullulans)和白色假丝酵母(Candida albicans)。年糕内部的微生物有巨大芽孢杆菌、枯草芽孢杆菌、短芽孢杆菌和白色假丝酵母,无霉菌。%Through the morphology observation and the physiological and biochemical of microorganisms which were separated and purified from the interior and the surface of the rice cake,we can get that there were 6 kinds of bacteri⁃um(involving 4 kinds of Bacillus which were Bacillus megaterium,Bacillus subtilis,Bacillus cereus and Bacillus bre⁃vis,2 kinds of non-Bacillus were Brevibacterium acetylicum and Acinetobacter calcoaceticus),3 kinds of molds(Rhizo⁃pus oryzae,Aspergillus oryzae and Aspergillus nidulans),and 2 kinds of Yeast(they were respectively Candida albi⁃cans and Trichosporon pullulans)on the surface of rice cake.The inside microorganisms of Rice cake were Bacillus megaterium,Bacillus subtilis,Bacillus brevis and trichosporon pullulans without mold.

  8. Investigation of the activity of the microorganisms in a Reblochon-style cheese by metatranscriptomic analysis

    Directory of Open Access Journals (Sweden)

    Christophe eMonnet

    2016-04-01

    Full Text Available The microbial communities in cheeses are composed of varying bacteria, yeasts, and molds, which contribute to the development of their typical sensory properties. In situ studies are needed to better understand their growth and activity during cheese ripening. Our objective was to investigate the activity of the microorganisms used for manufacturing a surface-ripened cheese by means of metatranscriptomic analysis. The cheeses were produced using two lactic acid bacteria (Streptococcus thermophilus and Lactobacillus delbrueckii ssp. bulgaricus, one ripening bacterium (Brevibacterium aurantiacum, and two yeasts (Debaryomyces hansenii and Geotrichum candidum. RNA was extracted from the cheese rinds and, after depletion of most ribosomal RNA, sequencing was performed using a short-read sequencing technology that generated approximately 75 million reads per sample. Except for Brevibacterium aurantiacum, which failed to grow in the cheeses, a large number of CDS reads were generated for the inoculated species, making it possible to investigate their individual transcriptome over time. From day 5 to day 35, G. candidum accounted for the largest proportion of CDS reads, suggesting that this species was the most active. Only minor changes occurred in the transcriptomes of the lactic acid bacteria. For the two yeasts, we compared the expression of genes involved in the catabolism of lactose, galactose, lactate, amino acids and free fatty acids. During ripening, genes involved in ammonia assimilation and galactose catabolism were down-regulated in the two species. Genes involved in amino acid catabolism were up-regulated in G. candidum from day 14 to day 35, whereas in D. hansenii, they were up-regulated mainly at day 35, suggesting that this species catabolized the cheese amino acids later. In addition, after 35 days of ripening, there was a down-regulation of genes involved in the electron transport chain, suggesting a lower cellular activity. The

  9. Temperature and relative humidity influence the microbial and physicochemical characteristics of Camembert-type cheese ripening.

    Science.gov (United States)

    Leclercq-Perlat, M-N; Sicard, M; Trelea, I C; Picque, D; Corrieu, G

    2012-08-01

    To evaluate the effects of temperature and relative humidity (RH) on microbial and biochemical ripening kinetics, Camembert-type cheeses were prepared from pasteurized milk seeded with Kluyveromyces marxianus, Geotrichum candidum, Penicillium camemberti, and Brevibacterium aurantiacum. Microorganism growth and biochemical changes were studied under different ripening temperatures (8, 12, and 16°C) and RH (88, 92, and 98%). The central point runs (12°C, 92% RH) were both reproducible and repeatable, and for each microbial and biochemical parameter, 2 kinetic descriptors were defined. Temperature had significant effects on the growth of both K. marxianus and G. candidum, whereas RH did not affect it. Regardless of the temperature, at 98% RH the specific growth rate of P. camemberti spores was significantly higher [between 2 (8°C) and 106 times (16°C) higher]. However, at 16°C, the appearance of the rind was no longer suitable because mycelia were damaged. Brevibacterium aurantiacum growth depended on both temperature and RH. At 8°C under 88% RH, its growth was restricted (1.3 × 10(7) cfu/g), whereas at 16°C and 98% RH, its growth was favored, reaching 7.9 × 10(9) cfu/g, but the rind had a dark brown color after d 20. Temperature had a significant effect on carbon substrate consumption rates in the core as well as in the rind. In the rind, when temperature was 16°C rather than 8°C, the lactate consumption rate was approximately 2.9 times higher under 88% RH. Whatever the RH, temperature significantly affected the increase in rind pH (from 4.6 to 7.7 ± 0.2). At 8°C, an increase in rind pH was observed between d 6 and 9, whereas at 16°C, it was between d 2 and 3. Temperature and RH affected the increasing rate of the underrind thickness: at 16°C, half of the cheese thickness appeared ripened on d 14 (wrapping day). However, at 98% RH, the underrind was runny. In conclusion, some descriptors, such as yeast growth and the pH in the rind, depended solely on

  10. Rizobactérias no controle da mancha angular do algodoeiro Rhizobacteria to control cotton bacterial blight

    Directory of Open Access Journals (Sweden)

    Alessandra Keiko Nakasone Ishida

    2008-02-01

    Full Text Available Avaliou-se o potencial de rizobactérias na indução de resistência do algodoeiro à Xanthomonas axonopodis pv. malvacearum. Após o isolamento das rizobactérias, foram selecionados os isolados capazes de reduzir os sintomas da mancha angular bacteriana em casa de vegetação, os quais foram aplicados espacialmente separados do patógeno desafiador. Os melhores isolados foram testados quanto à capacidade de reduzir os sintomas da ramulose e da murcha de Verticillium e de inibir diretamente os patógenos in vitro. Do total de 123 isolados de rizobactérias foram selecionados cinco, L2-1 (Bacillus cereus, MT5-6 (Bacillus cereus, L2-2 (Achromobacter xylosoxidans, MT5-5 (Bacillus cereus e MT5-11 (Brevibacterium sp., os quais apresentaram controle da mancha angular acima de 40%, em relação à testemunha. Nenhum isolado reduziu a severidade da ramulose e da murcha de Verticillium em relação à testemunha, nem apresentou efeito inibitório direto in vitro a X. axonopodis pv. malvacearum e Colletotrichum gossypii var. cephalosporioides. Para V. dahliae, apenas o isolado L2-1 apresentou efeito inibitório.The potential of rhizobacteria was evaluated for resistance induction against Xanthomonas axonopodis pv. malvacearum. After isolation, the rhizobacteria were screened for the reduction of angular leaf spot severity under greenhouse conditions. They were spatially separated from the challenging pathogen. The best isolates were tested for the capacity to reduce ramulose and Verticillium wilt severity and directly inhibit pathogens in vitro. From a total of 123 rhizobacterial isolates, five were selected, L2-1 (Bacillus cereus, MT5-6 (Bacillus cereus, L2-2 (Achromobacter xylosoxidans, MT5-5 (Bacillus cereus and MT5-11 (Brevibacterium sp., which showed angular leaf spot control above 40% as compared to the control. The tested isolates neither reduced the severity of ramulose and verticillium wilt compared to the control nor showed in vitro direct

  11. 兴安落叶松林土壤微生物分布%THE DISTRIBUTION OF SOIL MICROORGANISM IN Larix gmelinii FOREST

    Institute of Scientific and Technical Information of China (English)

    李晓彤; 姜海燕; 闰伟; 赵洪凯; 董内涵

    2011-01-01

    本研究利用选择性培养基,研究了原始林中的草类-落叶松林(HLV)、柴桦-落叶松林(BLV),被干扰林中的皆伐-落叶松林(CL)、渐伐-落叶松林(SL)的土壤微生物的数量和种群组成.结果表明:土壤微生物随季节的变化是7月大于5月、9月,微生物的垂直变化是随着土层深度的增加,微生物数量呈递减趋势.从原始林与干扰林中共分离到细菌18属,优势菌属为短杆菌属(Brevibacterium)、芽孢杆菌属(Bacillus)、棒杆菌属(Corynebacterium)、微球菌属(Micrococcus);放线菌8属,优势属为链霉菌属(Streptomyces)、诺卡氏菌属(Nocardia);真菌18属,优势菌属为青霉属(Penicillium)和头孢属(Cephalosporium).%The population structure and numbers of soil microorganisms in different forest types were studied in Ledwn palustre -Herbage -L. Gmelinii virgin forest, Betula -L gmelinii virgin forest of the primary forest and clear cutting L. Gmelinii forest .successive cutting L. Gmelinii forest of the disturbed forest in the national forestry ecosystems station of Inner Mongolia Great Xingan Mountains by selective media. The results showed that the quantity of total microorganisms were July > May and September, the quantity of soil microorganisms were gradual lower with the increasing in vertical depth, follow orders: 0 - 10cm layer > 10 -20cm layer >20 -30cm layer. Bacteria isolated from plots belonged to 18 genera, Brevibacterium,Bacillus,Corynebacterium and Micrococcus were main genera; actinomycetes were composed of 8 genera, Streptomyces and Nocardia were the main genera; fungi were composed of 18 genera, Peni-cillium and Cephalosporium were the dominant genera from the primary forest and disturbed forest.

  12. Studying of Phenomenon of Biological Adaptation to Heavy Water

    Directory of Open Access Journals (Sweden)

    Oleg Mosin

    2014-12-01

    Full Text Available Biological influence of deuterium on cells of various taxonomic groups of prokaryotic and eucaryotic microorganisms realizing methylotrophic, chemoheterotrophic, photo-organotrophic, and photosynthetic ways of assimilation of carbon substrates (methylotrophic bacteria Brevibacterium methylicum, chemoheterotrophic bacteria Bacillus subtilis, photo-organotrophic halobacteria Halobacterium halobium, and green micro algae Chlorella vulgaris was investigated at the growth on media with heavy water (2H2O. For investigated microorganisms are submitted the data on growth and adaptation on the growth media containing as sources of deuterated substrates 2H2O, [2H]methanol and hydrolisates of deutero-biomass of methylotrophic bacteria B. methylicum, obtained after multistage adaptation to 2H2O. The qualitative and quantitative composition of intra- and endocellular amino acids, proteins, carbohydrates and fatty acids in conditions of adaptation to 2H2O is investigated. It is shown, that the effects observed at adaptation to 2H2O, possess a complex multifactorial character and connected to cytological, morphological and physiological changes – the magnitude of the lag- period, time of cellular generation, output of biomass, a parity ratio of synthesized amino acids, proteins, carbohydrates and lipids, and also with an evolutionary level of the organization of the investigated object and the pathways of assimilation of carbon substrates as well.

  13. Diversity and Biomineralization Potential of the Epilithic Bacterial Communities Inhabiting the Oldest Public Stone Monument of Cluj-Napoca (Transylvania, Romania)

    Science.gov (United States)

    Andrei, Adrian-Ştefan; Păuşan, Manuela R.; Tămaş, Tudor; Har, Nicolae; Barbu-Tudoran, Lucian; Leopold, Nicolae; Banciu, Horia L.

    2017-01-01

    In this study, we investigated the biomineralization potential and diversity of the epilithic bacterial communities dwelling on the limestone statue of Saint Donatus, the oldest public monument of Cluj-Napoca city (Transylvania region, NW Romania). Their spatial distribution together with phylogenetic and metabolic diversity, as well as their capacity to precipitate calcium carbonate was evaluated by combining molecular and phenotypic fingerprinting methods with X-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron-microscopy analyses. The results of real-time quantitative PCR, molecular fingerprinting and community-level physiological profiling showed that diverse and abundant bacterial assemblages that differ in relation to their collection site colonized the statue. The cultivation and molecular identification procedures allowed the characterization of 79 bacterial isolates belonging to Proteobacteria (73.4%), Firmicutes (19%), and Actinobacteria (7.6%). Amongst them, the 22 strains identified as being capable of calcium carbonate precipitation were found to belong mostly to Bacillus and Pseudomonas genera. We found that bacteria acted as nucleation sites, inducing the formation of nanoscale aggregates that were shown to be principally composed of vaterite. Furthermore, we expanded the current knowledge on culturable diversity of carbonatogenic bacteria by providing evidence for biogenic vaterite/calcite formation mediated by: Pseudomonas synxantha, P. graminis, Brevibacterium iodinum, Streptomyces albidoflavus, and Stenotrophomonas chelatiphaga. Overall, this study highlights the need to evaluate the carbonatogenetic potential of all the bacterial communities present on stone artwork prior to designing an efficient conservation treatment based on biomineralization. PMID:28326074

  14. Non-spore forming eubacteria isolated at an altitude of 20,000 m in Earth's atmosphere: extended incubation periods needed for culture-based assays

    Science.gov (United States)

    Griffin, Dale W.

    2008-01-01

    On 13 August 2004, an atmospheric sample was collected at an altitude of 20,000 m along a west to east transect over the continental United States by NASA’s Stratospheric and Cosmic Dust Program. This sample was then shipped to the US Geological Survey’s Global Desert Dust program for microbiological analyses. This sample, which was plated on a low nutrient agar to determine if cultivable microorganisms were present, produced 590 small yellow to off-white colonies after approximately 7 weeks of incubation at room-temperature. Of 50 colonies selected for identification using 16S rRNA sequencing, 41 belonged to the family Micrococcaceae, seven to the family Microbacteriaceae, one to the genus Staphylococcus, and one to the genus Brevibacterium. All of the isolates identified were non-spore-forming pigmented bacteria, and their presence in this sample illustrate that it is not unusual to recover viable microbes at extreme altitudes. Additionally, the extended period required to initiate growth demonstrates the need for lengthy incubation periods when analyzing high-altitude samples for cultivable microorganisms.

  15. Modification of chimeric (2S, 3S)-butanediol dehydrogenase based on structural information.

    Science.gov (United States)

    Shimegi, Tomohito; Mochizuki, Kaito; Oyama, Takuji; Ohtsuki, Takashi; Kusunoki, Masami; Ui, Sadaharu

    2014-01-01

    A chimeric (2S, 3S)-butanediol dehydrogenase (cLBDH) was engineered to have the strict (S)-configuration specificity of the (2S, 3S)-BDH (BsLBDH) derived from Brevibacterium saccharolyticum as well as the enzymatic stability of the (2R, 3S)-BDH (KpMBDH) from Klebsiella pneumonia by swapping the domains of two native BDHs. However, while cLBDH possesses the stability, it lacks the specificity. In order to assist in the design a BDH having strict substrate specificity, an X-ray structural analysis of a cLBDH crystal was conducted at 1.58 Å. The results obtained show some readily apparent differences around the active sites of cLBDH and BsLBDH. Based on this structural information, a novel (2S, 3S)-BDH having a preferred specificity was developed by introducing a V254L mutation into cLBDH. The influence of this mutation on the stability of cLBDH was not evaluated. Nevertheless, the technique described herein is an effective method for the production of a tailor-made BDH.

  16. Diversity, ecological distribution and biotechnological potential of Actinobacteria inhabiting seamounts and non-seamounts in the Tyrrhenian Sea

    KAUST Repository

    Ettoumi, Besma

    2016-04-01

    In the present study, the ecological distribution of marine Actinobacteria isolated from seamount and non-seamount stations in the Tyrrhenian Sea was investigated. A collection of 110 isolates was analyzed by Automated Ribosomal Intergenic Spacer Analysis (ARISA) and 16S rRNA gene sequencing of representatives for each ARISA haplotype (n = 49). Phylogenetic analysis of 16S rRNA sequences showed a wide diversity of marine isolates and clustered the strains into 11 different genera, Janibacter, Rhodococcus, Arthrobacter, Kocuria, Dietzia, Curtobacterium, Micrococcus, Citricoccus, Brevibacterium, Brachybacterium and Nocardioides. Interestingly, Janibacter limosus was the most encountered species particularly in seamounts stations, suggesting that it represents an endemic species of this particular ecosystem. The application of BOX-PCR fingerprinting on J. limosus sub-collection (n = 22), allowed their separation into seven distinct BOX-genotypes suggesting a high intraspecific microdiversity among the collection. Furthermore, by screening the biotechnological potential of selected actinobacterial strains, J. limosus was shown to exhibit the most important biosurfactant activity. Our overall data indicates that Janibacter is a major and active component of seamounts in the Tyrrhenian Sea adapted to low nutrient ecological niche.

  17. New recombinant cyclohexylamine oxidase variants for deracemization of secondary amines by orthogonally assaying designed mutants with structurally diverse substrates

    Science.gov (United States)

    Li, Guangyue; Yao, Peiyuan; Cong, Peiqian; Ren, Jie; Wang, Lei; Feng, Jinhui; Lau, Peter C. K.; Wu, Qiaqing; Zhu, Dunming

    2016-05-01

    To further expand the substrate range of the cyclohexylamine oxidase (CHAO) from Brevibacterium oxydans, a library of diverse mutants was created and assayed toward a group of structurally diverse substrates. Among them, mutants T198A and M226A exhibited enhanced activity relative to wt CHAO for most (S)-enantiomers of primary amines and some secondary amines. While mutants T198I, L199I, L199F, M226I and M226T were more active than wt CHAO toward the primary amines, mutants T198F, L199T, Y321A, Y321T, Y321I and Y321F enhanced the enzyme activity toward the secondary amines. In particular, mutant Y321I displayed an enhanced catalytic efficiency toward 1-(4-methoxybenzyl)-1, 2, 3, 4, 5, 6, 7, 8-octahydroisoquinoline (13). Whereas a double mutant, Y321I/M226T, acted on (S)-N-(prop-2-yn-1-yl)-2, 3-dihydro-1H-inden-1-amine [(S)-8]. Since (R)-8 is an irreversible inhibitor of monoamine oxidase and (S)-13 is an intermediate of dextromethorphan, a cough suppressant drug, deracemizations of 8 and 13 were carried out with crude enzyme extracts of the respective mutants. This resulted in 51% and 78% isolated yields of (R)-8 and (S)-13, respectively, each with high enantiomeric excess (93% and 99% ee). The results demonstrated the application potential of the evolved CHAO mutants in drug synthesis requiring chiral secondary amines.

  18. Phylogenetic diversity and biological activity of actinobacteria isolated from the Chukchi Shelf marine sediments in the Arctic Ocean.

    Science.gov (United States)

    Yuan, Meng; Yu, Yong; Li, Hui-Rong; Dong, Ning; Zhang, Xiao-Hua

    2014-03-06

    Marine environments are a rich source of Actinobacteria and have the potential to produce a wide variety of biologically active secondary metabolites. In this study, we used four selective isolation media to culture Actinobacteria from the sediments collected from the Chukchi Shelf in the Arctic Ocean. A total of 73 actinobacterial strains were isolated. Based on repetitive DNA fingerprinting analysis, we selected 30 representatives for partial characterization according to their phylogenetic diversity, antimicrobial activities and secondary-metabolite biosynthesis genes. Results from the 16S rRNA gene sequence analysis indicated that the 30 strains could be sorted into 18 phylotypes belonging to 14 different genera: Agrococcus, Arsenicicoccus, Arthrobacter, Brevibacterium, Citricoccus, Janibacter, Kocuria, Microbacterium, Microlunatus, Nocardioides, Nocardiopsis, Saccharopolyspora, Salinibacterium and Streptomyces. To our knowledge, this paper is the first report on the isolation of Microlunatus genus members from marine habitats. Of the 30 isolates, 11 strains exhibited antibacterial and/or antifungal activity, seven of which have activities against Bacillus subtilis and Candida albicans. All 30 strains have at least two biosynthetic genes, one-third of which possess more than four biosynthetic genes. This study demonstrates the significant diversity of Actinobacteria in the Chukchi Shelf sediment and their potential for producing biologically active compounds and novel material for genetic manipulation or combinatorial biosynthesis.

  19. Isolation and characterisation of 1-alkyl-3-methylimidazolium chloride ionic liquid-tolerant and biodegrading marine bacteria.

    Directory of Open Access Journals (Sweden)

    Julianne Megaw

    Full Text Available The aim of this study was to isolate and identify marine-derived bacteria which exhibited high tolerance to, and an ability to biodegrade, 1-alkyl-3-methylimidazolium chloride ionic liquids. The salinity and hydrocarbon load of some marine environments may induce selective pressures which enhance the ability of microbes to grow in the presence of these liquid salts. The isolates obtained in this study generally showed a greater ability to grow in the presence of the selected ionic liquids compared to microorganisms described previously, with two marine-derived bacteria, Rhodococcus erythropolis and Brevibacterium sanguinis growing in concentrations exceeding 1 M 1-ethyl-3-methylimidazolium chloride. The ability of these bacteria to degrade the selected ionic liquids was assessed using High Performance Liquid Chromatography (HPLC, and three were shown to degrade the selected ionic liquids by up to 59% over a 63-day test period. These bacterial isolates represent excellent candidates for further potential applications in the bioremediation of ionic liquid-containing waste or following accidental environmental exposure.

  20. Identification and antibiotic action of an anti-aflatoxin strain from Domiati cheese%Domiati奶酪中抗黄曲霉毒素活性物质产生菌的分离鉴定及其抑菌作用

    Institute of Scientific and Technical Information of China (English)

    畅晓渊; 刘国荣; 李平兰; Magdy M.Osrnan; 吴寒宇

    2009-01-01

    通过抑菌活性试验、蛋白酶敏感性试验、菌株的动力学生长曲线测定,菌株的生理生化试验以及1 6S rRNA序列鉴定试验,对埃及传统Domiati奶酪中的产抗黄曲霉毒素的活性物质的菌株进行分离与鉴定.结果显示:分离得到的菌株的发酵上清液对多株受试真菌均有明显抑制作用,尤其对产生黄曲霉毒素的黄曲霉(Asper-gillus flauus)有很强的抑制效果;该菌株产生的抑菌活性物质不是蛋白类物质,也不同于一般细菌素;该菌鉴定为扩展短杆菌(Brevibacterium linens),命名为lpl-8菌.

  1. Antibacterial activity of silver nanoparticle-coated fabric and leather against odor and skin infection causing bacteria.

    Science.gov (United States)

    Velmurugan, Palanivel; Lee, Sang-Myeong; Cho, Min; Park, Jung-Hee; Seo, Sang-Ki; Myung, Hyun; Bang, Keuk-Soo; Oh, Byung-Taek

    2014-10-01

    We present a simple, eco-friendly synthesis of silver and gold nanoparticles using a natural polymer pine gum solution as the reducing and capping agent. The pine gum solution was combined with silver nitrate (AgNO3) or a chloroauric acid (HAuCl4) solution to produce silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs), respectively. The reaction process was simple; formation of the nanoparticles was achieved by autoclaving the silver and gold ions with the pine gum. UV-Vis spectra showed surface plasmon resonance (SPR) for silver and gold nanoparticles at 432 and 539 nm, respectively. The elemental forms of AgNPs and AuNPs were confirmed by energy-dispersive X-ray spectroscopy (EDX). Fourier transform infrared spectroscopy (FTIR) showed the biomolecules present in the pine gum, AgNPs, and AuNPs. Transmission electron microscopy (TEM) images showed the shape and size of AgNPs and AuNPs. The crystalline nature of synthesized AgNPs and AuNPs was confirmed by X-ray crystallography [X-ray diffraction (XRD)]. Application of synthesized AgNPs onto cotton fabrics and leather, in order to evaluate their antibacterial properties against odor- or skin infection-causing bacteria, is also discussed. Among the four tested bacteria, AgNP-coated cotton fabric and leather samples displayed excellent antibacterial activity against Brevibacterium linens.

  2. Antimicrobial fabrication of cotton fabric and leather using green-synthesized nanosilver.

    Science.gov (United States)

    Velmurugan, Palanivel; Cho, Min; Lee, Sang-Myeong; Park, Jung-Hee; Bae, Sunyoung; Oh, Byung-Taek

    2014-06-15

    This study aims to investigate the green synthesis of silver nanoparticles (AgNPs) by Erigeron annuus (L.) pers flower extract as reducing and capping agent, and evaluation of their antibacterial activities for the first time. The obtained product was confirmed by UV-Vis spectrum, high resolution-transmission electron microscopy, energy-dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, and X-ray diffraction studies. The optimum AgNPs production was achieved at pH 7, metal silver (Ag(+) ion) concentration of 2.0mM, flower extract concentration 4%, and time 335 min. In addition, the antibacterial activity of cotton fabrics and tanned leather loaded with AgNPs, commercial AgNPs, flower extract, Ag(+) ion and blend of flower extract with AgNPs were evaluated against Gram-positive odor causing bacteria Brevibacterium linens and Staphylococcus epidermidis. The results showed maximum zone of inhibition (ZOI) by the cotton fabrics embedded with blend of flower extract and AgNPs against B. linens. The structure and morphology of cotton fabric and leather samples embedded with AgNPs, Ag(+) ion and blend of flower extract with AgNPs were examined under field emission scanning electron microscope.

  3. Characterization of 15 selected coccal bacteria isolated from Antarctic rock and soil samples from the McMurdo-Dry Valleys (South-Victoria Land)

    Science.gov (United States)

    Siebert, J.; Hirsch, P.; Friedmann, E. I. (Principal Investigator)

    1988-01-01

    Approximately 1500 cultures of microorganisms were isolated from rocks and soils of the Ross Desert (McMurdo-Dry Valleys). From these, 15 coccoid strains were chosen for more detailed investigation. They were characterized by morphological, physiological and chemotaxonomical properties. All isolates were Gram-positive, catalase-positive and nonmotile. Six strains showed red pigmentation and could be identified as members of the genera Micrococcus (M. roseus, M. agilis) or Deinococcus. In spite of their coccoid morphology, the remaining nine strains had to be associated with coryneform bacteria (Arthrobacter, Brevibacterium), because of their cell wall composition and G+C ratios. Most of the strains were psychrotrophic, but one strain was even obligately psychrophilic, with a temperature maximum below 20 degrees C. Red cocci had in vitro pH optima above 9.0 although they generally originated from acid samples. Most isolates showed a preference for sugar alcohols and organic acids, compounds which are commonly known to be released by lichens, molds and algae, the other components of the cryptoendolithic ecosystem. These properties indicate that our strains are autochthonous members of the natural Antarctic microbial population.

  4. Paratrechina longicornis ants in a tropical dry forest harbor specific Actinobacteria diversity.

    Science.gov (United States)

    Reyes, Ruth D Hernández; Cafaro, Matías J

    2015-01-01

    The diversity of Actinobacteria associated with Paratrechina longicornis, an ant species that prefers a high protein diet, in a subtropical dry forest (Guánica, Puerto Rico) was determined by culture methods and by 16S rDNA clone libraries. The results of both methodologies were integrated to obtain a broader view of the diversity. Streptomyces, Actinomadura, Nocardia, Ornithinimicrobium, Tsukamurella, Brevibacterium, Saccharopolyspora, Nocardioides, Microbacterium, Leifsonia, Pseudonocardia, Corynebacterium, Geodermatophilus, Amycolatopsis, and Nonomuraea were found associated with the ants. The genera Streptomyces and Actinomadura were the most abundant. Also, the diversity of Actinobacteria associated with the soil surrounding the nest was determined using 16S rDNA clone libraries. In total, 27 genera of Actinobacteria were associated with the nest soils. A dominant genus was not observed in any of the soil samples. We compared statistically the Actinobacteria communities among P. longicornis nests and each nest with its surrounding soil using the clone libraries data. We established that the communities associated with the ants were consistent and significantly different from those found in the soil in which the ants live.

  5. Isolation and identification of high-activity flocculation bacteria in potato starch wastewater%马铃薯淀粉废水高活性絮凝菌的分离鉴定

    Institute of Scientific and Technical Information of China (English)

    赵起政; 路宏科; 彭涛; 马文锦; 陈兴叶; 殷欣; 张小燕; 杨旭星; 金红

    2015-01-01

    从马铃薯淀粉废水和黄河污水排放口附近的污泥中分离得到300株菌,对所分离的菌株进行分离纯化,初筛和复筛,得到6株絮凝活性在60%以上的细菌,对6株细菌进行形态特征分析,将复筛的6株细菌悬液按照等体积的比例进行复配,絮凝率最高的混合菌为N1和N2,达到96.41%,选取絮凝率80%以上的4组构建菌中的5株细菌,对其进行16S rDNA序列分析,鉴定结果为N1短杆菌属(Brevibacterium sp.)、N2短小芽孢杆菌(Bacillus pumilus)、N3希瓦氏菌属(Shewanella sp.)、N4赖氨酸芽孢杆茵(Lysinibacillus fusiformis)、N5解鸟氨酸拉乌尔菌(Raoultella omithinolytica).

  6. 降解除草剂异噁草酮细菌的分离、鉴定及生长特性%Studies on screening, identification and growth characters of the herbicide clomazone degrading-bacteria

    Institute of Scientific and Technical Information of China (English)

    刘亚光; 闫春秀; 赵滨

    2007-01-01

    利用长期施用长残留除草剂的土壤,采用高压富集的方法,从两种培养液中共分离出3株细菌,根据菌株的形态特性和生理生化特征,对此3个菌株进行了初步鉴定:W2为短杆菌属(Brevibacterium);Y1和X同为芽胞杆菌属(Bacillus);W2、Y1和X的最适生长温度分别是30℃、35℃和30℃;W2培养基的pH值为6.0~9.0,Y1和X的最适pH值为6.0~8.0;W2生长最适异噁草酮的浓度是200mg a.i.·L-1,Y1和X生长最适异噁草酮的浓度是100mg a..i.·L-1.

  7. Gold nanoparticles mediated coloring of fabrics and leather for antibacterial activity.

    Science.gov (United States)

    Velmurugan, Palanivel; Shim, Jaehong; Bang, Keuk-Soo; Oh, Byung-Taek

    2016-07-01

    Metal gold nanoparticles (AuNPs) were synthesized in situ onto leather, silk and cotton fabrics by three different modules, including green, chemical, and a composite of green and chemical synthesis. Green synthesis was employed using Ginkgo biloba Linn leaf powder extract and HAuCl4 with the fabrics, and chemical synthesis was done with KBH4 and HAuCl4. For composite synthesis, G. biloba extract and KBH4 were used to color and embed AuNPs in the fabrics. The colored fabrics were tested for color coordination and fastness properties. To validate the green synthesis of AuNPs, various instrumental techniques were used including UV-Vis spectrophotometry, HR-TEM, FTIR, and XRD. The chemical and composite methods reduce Au(+) onto leather, silk and cotton fabrics upon heating, and alkaline conditions are required for bonding to fibers; these conditions are not used in the green synthesis protocol. FE-SEM image revealed the binding nature of the AuNPs to the fabrics. The AuNPs that were synthesized in situ on the fabrics were tested against a skin pathogen, Brevibacterium linens using LIVE/DEAD BacLight Bacterial Viability testing. This study represents an initial route for coloring and bio-functionalization of various fabrics with green technologies, and, accordingly, should open new avenues for innovation in the textile and garment sectors.

  8. Study of the Production Conditions and Bacteriolytic Specificity of Bacteriolytic Enzyme RX-17 Produced by Streptomyces sp%链霉菌RX-17溶菌酶的产生条件及溶菌特异性研究

    Institute of Scientific and Technical Information of China (English)

    赵昕; 任光文; 屠晓平; 张玉臻

    2003-01-01

    通过液体及平板溶菌活性测定,证明了灰色链霉菌(Streptomyces griseus)RX-17发酵液中存在对变链球菌(Streptococcus mutans)Ingbritt有强力溶解作用的物质-RX-17溶菌酶.产酶培养基碳、氮源最适配比为蔗糖3%、大豆蛋白胨1.25%、牛肉膏0.2%;最适产酶温度为33℃;高溶氧水平对酶的产生有利.溶菌特异性试验证实了RX-17溶菌酶对金黄色葡萄球菌(Staphylococcus aureus)、乳脂链球菌(S.cremoris)、保加利亚乳杆菌(Lactoba-cillus bulgaricus)、短乳杆菌(L.brevis)、产氨短杆菌(Brevibacterium ammoniagenes)及铜绿假单胞菌(Pseudomonasaeruginosa)等多种G+、G-细菌均有良好的溶解作用.

  9. Biosynthesis, characterization, and antimicrobial applications of silver nanoparticles.

    Science.gov (United States)

    Singh, Priyanka; Kim, Yeon Ju; Singh, Hina; Wang, Chao; Hwang, Kyu Hyon; Farh, Mohamed El-Agamy; Yang, Deok Chun

    2015-01-01

    In the present study, the strain Brevibacterium frigoritolerans DC2 was explored for the efficient and extracellular synthesis of silver nanoparticles. These biosynthesized silver nanoparticles were characterized by ultraviolet-visible spectrophotometry, which detected the formation of silver nanoparticles in the reaction mixture and showed a maximum absorbance at 420 nm. In addition, field emission transmission electron microscopy revealed the spherical shape of the nanoparticles. The dynamic light scattering results indicated the average particle size of the product was 97 nm with a 0.191 polydispersity index. Furthermore, the product was analyzed by energy dispersive X-ray spectroscopy, X-ray diffraction, and elemental mapping, which displayed the presence of elemental silver in the product. Moreover, on a medical platform, the product was checked against pathogenic microorganisms including Vibrio parahaemolyticus, Salmonella enterica, Bacillus anthracis, Bacillus cereus, Escherichia coli, and Candida albicans. The nanoparticles demonstrated antimicrobial activity against all of these pathogenic microorganisms. Additionally, the silver nanoparticles were evaluated for their combined effects with the commercial antibiotics lincomycin, oleandomycin, vancomycin, novobiocin, penicillin G, and rifampicin against these pathogenic microorganisms. These results indicated that the combination of antibiotics with biosynthesized silver nanoparticles enhanced the antimicrobial effects of antibiotics. Therefore, the current study is a demonstration of an efficient biological synthesis of silver nanoparticles by B. frigoritolerans DC2 and its effect on the enhancement of the antimicrobial efficacy of well-known commercial antibiotics.

  10. Long-term nitrogen fertilization decreased the abundance of inorganic phosphate solubilizing bacteria in an alkaline soil

    Science.gov (United States)

    Zheng, Bang-Xiao; Hao, Xiu-Li; Ding, Kai; Zhou, Guo-Wei; Chen, Qing-Lin; Zhang, Jia-Bao; Zhu, Yong-Guan

    2017-02-01

    Inorganic phosphate solubilizing bacteria (iPSB) are essential to facilitate phosphorus (P) mobilization in alkaline soil, however, the phylogenetic structure of iPSB communities remains poorly characterized. Thus, we use a reference iPSB database to analyze the distribution of iPSB communities based on 16S rRNA gene illumina sequencing. Additionally, a noval pqqC primer was developed to quantify iPSB abundance. In our study, an alkaline soil with 27-year fertilization treatment was selected. The percentage of iPSB was 1.10~2.87% per sample, and the dominant iPSB genera were closely related to Arthrobacter, Bacillus, Brevibacterium and Streptomyces. Long-term P fertilization had no significant effect on the abundance of iPSB communities. Rather than P and potassium (K) additions, long-term nitrogen (N) fertilization decreased the iPSB abundance, which was validated by reduced relative abundance of pqqC gene (pqqC/16S). The decreased iPSB abundance was strongly related to pH decline and total N increase, revealing that the long-term N additions may cause pH decline and subsequent P releases relatively decreasing the demands of the iPSB community. The methodology and understanding obtained here provides insights into the ecology of inorganic P solubilizers and how to manipulate for better P use efficiency.

  11. Long-term nitrogen fertilization decreased the abundance of inorganic phosphate solubilizing bacteria in an alkaline soil

    Science.gov (United States)

    Zheng, Bang-Xiao; Hao, Xiu-Li; Ding, Kai; Zhou, Guo-Wei; Chen, Qing-Lin; Zhang, Jia-Bao; Zhu, Yong-Guan

    2017-01-01

    Inorganic phosphate solubilizing bacteria (iPSB) are essential to facilitate phosphorus (P) mobilization in alkaline soil, however, the phylogenetic structure of iPSB communities remains poorly characterized. Thus, we use a reference iPSB database to analyze the distribution of iPSB communities based on 16S rRNA gene illumina sequencing. Additionally, a noval pqqC primer was developed to quantify iPSB abundance. In our study, an alkaline soil with 27-year fertilization treatment was selected. The percentage of iPSB was 1.10~2.87% per sample, and the dominant iPSB genera were closely related to Arthrobacter, Bacillus, Brevibacterium and Streptomyces. Long-term P fertilization had no significant effect on the abundance of iPSB communities. Rather than P and potassium (K) additions, long-term nitrogen (N) fertilization decreased the iPSB abundance, which was validated by reduced relative abundance of pqqC gene (pqqC/16S). The decreased iPSB abundance was strongly related to pH decline and total N increase, revealing that the long-term N additions may cause pH decline and subsequent P releases relatively decreasing the demands of the iPSB community. The methodology and understanding obtained here provides insights into the ecology of inorganic P solubilizers and how to manipulate for better P use efficiency. PMID:28181569

  12. Allergic alveolitis among agricultural workers in eastern Poland: a study of twenty cases.

    Science.gov (United States)

    Milanowski, J; Dutkiewicz, J; Potoczna, H; Kuś, L; Urbanowicz, B

    1998-01-01

    The aim of this study was to identify the specific agents which caused extrinsic allergic alveolitis (EAA) in the selected group of 20 agricultural workers from eastern Poland. The microbiological analysis of the samples of plant materials or dusts reported by the patients as causing symptoms has been carried out, followed by allergological tests (inhalation challenge, agar-gel precipitation test, inhibition of leukocyte migration, skin test) with extrinsic microbial antigens. It was found that the causative agents of allergic alveolitis in the examined group of patients were mesophilic, non-branching bacteria associated with grain dust, mostly Pantoea agglomerans (synonyms: Erwinia herbicola, Enterobacter agglomerans) and Arthrobacter globiformis (each in eight cases). The remaining agents were Alcaligenes faecalis (in two cases), and Brevibacterium linens and Staphylococcus epidermidis (in one case each). On the basis of the clinical picture, the bronchoalveolar lavage (BAL) and allergological tests, the diagnosis of the chronic form of the disease was stated in 14 patients and an acute form - in 6 patients. EAA patients demonstrated in the BAL fluid a typical lymphocytic alveolitis both in terms of percentage and absolute number of lymphocytes. Also, the numbers of eosinophils and neutrophils were significantly higher in EAA patients.

  13. A methodological approach to screen diverse cheese-related bacteria for their ability to produce aroma compounds.

    Science.gov (United States)

    Pogačić, Tomislav; Maillard, Marie-Bernadette; Leclerc, Aurélie; Hervé, Christophe; Chuat, Victoria; Yee, Alyson L; Valence, Florence; Thierry, Anne

    2015-04-01

    Microorganisms play an important role in the development of cheese flavor. The aim of this study was to develop an approach to facilitate screening of various cheese-related bacteria for their ability to produce aroma compounds. We combined i) curd-based slurry medium incubated under conditions mimicking cheese manufacturing and ripening, ii) powerful method of extraction of volatiles, headspace trap, coupled to gas chromatography-mass spectrometry (HS-trap-GC-MS), and iii) metabolomics-based method of data processing using the XCMS package of R software and multivariate analysis. This approach was applied to eleven species: five lactic acid bacteria (Leuconostoc lactis, Lactobacillus sakei, Lactobacillus paracasei, Lactobacillus fermentum, and Lactobacillus helveticus), four actinobacteria (Brachybacterium articum, Brachybacterium tyrofermentans, Brevibacterium aurantiacum, and Microbacterium gubbeenense), Propionibacterium freudenreichii, and Hafnia alvei. All the strains grew, with maximal populations ranging from 7.4 to 9.2 log (CFU/mL). In total, 52 volatile aroma compounds were identified, of which 49 varied significantly in abundance between bacteria. Principal component analysis of volatile profiles differentiated species by their ability to produce ethyl esters (associated with Brachybacteria), sulfur compounds and branched-chain alcohols (H. alvei), branched-chain acids (H. alvei, P. freudenreichii and L. paracasei), diacetyl and related carbonyl compounds (M. gubbeenense and L. paracasei), among others.

  14. Survival of cheese-ripening microorganisms in a dynamic simulator of the gastrointestinal tract.

    Science.gov (United States)

    Adouard, Nadège; Magne, Laurent; Cattenoz, Thomas; Guillemin, Hervé; Foligné, Benoît; Picque, Daniel; Bonnarme, Pascal

    2016-02-01

    A mixture of nine microorganisms (six bacteria and three yeasts) from the microflora of surface-ripened cheeses were subjected to in vitro digestive stress in a three-compartment "dynamic gastrointestinal digester" (DIDGI). We studied the microorganisms (i) grown separately in culture medium only (ii) grown separately in culture medium and then mixed, (iii) grown separately in culture medium and then included in a rennet gel and (iv) grown together in smear-ripened cheese. The yeasts Geotrichum candidum, Kluyveromyces lactis and Debaryomyces hansenii, were strongly resistant to the whole DIDGI process (with a drop in viable cell counts of less than cheese-grown cultures. Ripening bacteria such as Hafnia alvei survived gastric stress less well when grown in cheese (with no viable cells after 90 min of exposure of the cheese matrix, compared with 6 CFU mL(-1) in lab cultures). The ability of Corynebacterium casei and Staphylococcus equorum to withstand digestive stress was similar for cheese and pure culture conditions. When grow in a cheese matrix, Brevibacterium aurantiacum and Arthrobacter arilaitensis were clearly more sensitive to the overall digestive process than when grown in pure cultures. Lactococcus lactis displayed poorer survival in gastric and duodenal compartments when it had been grown in cheese. In vivo experiments in BALB/c mice agreed with the DIDGI experiments and confirmed the latter's reliability.

  15. Antioxidant/Prooxidant and Antibacterial/Probacterial Effects of a Grape Seed Extract in Complex with Lipoxygenase

    Directory of Open Access Journals (Sweden)

    Veronica Sanda Chedea

    2014-01-01

    Full Text Available In an attempt to determine the antioxidant/prooxidant, antibacterial/probacterial action of flavan-3-ols and procyanidins from grape seeds, pure catechin (CS, and an aqueous grape seed extract (PE, were applied in the absence and presence of pure lipoxygenase (LS or in extract (LE to leucocyte culture, Escherichia coli B41 and Brevibacterium linens, and observed whether there was any effect on lipid peroxidation, cytotoxicity, or growth rate. Short time periods of coincubation of cells with the polyphenols, followed by the exposure to LS and LE, revealed a high level of lipid peroxidation and a prooxidative effect. Longer coincubation and addition of LS and LE resulted in the reversal of the prooxidant action either to antioxidant activity for CS + LS and PE + LS or to the control level for CS + LE and PE + LE. Lipid peroxidation was significantly reduced when cells were exposed to polyphenols over a longer period. Longer exposure of E. coli to CS or PE followed by addition of LS for 3 h resulted in bactericidal activity. Significant stimulatory effect on microbial growth was observed for PE + LS and PE + LE treatments in B. linens, illustrating the potential probacterial activity in B. linens cultures. Lipoxygenase-polyphenols complex formation was found to be responsible for the observed effects.

  16. Utilization of soluble starch by a recombinant Corynebacterium glutamicum strain: growth and lysine production.

    Science.gov (United States)

    Seibold, Gerd; Auchter, Marc; Berens, Stephan; Kalinowski, Jörn; Eikmanns, Bernhard J

    2006-07-13

    Corynebacterium glutamicum, well known for the industrial production of amino acids, grows aerobically on a variety of mono- and disaccharides and on alcohols and organic acids as single or combined sources of carbon and energy. Members of the genera Corynebacterium and Brevibacterium were here tested for their ability to use the homopolysaccharide starch as a substrate for growth. None of the 24 type strains tested showed growth on or degradation of this substrate, indicating that none of the strains synthesized and secreted starch-degrading enzymes. Introducing the Streptomyces griseus amy gene on an expression vector into the lysine-producer C. glutamicum DM1730, we constructed a C. glutamicum strain synthesizing and secreting alpha-amylase into the culture broth. Although some high-molecular-weight degradation products remained in the culture broth, this recombinant strain effectively used soluble starch as carbon and energy substrate for growth and also for lysine production. Thus, employment of our construct allows avoidance of the cost-intensive enzymatic hydrolysis of the starch, which commercially is used as a substrate in industrial amino acid fermentations.

  17. Synthesis and characterization of nanosilver with antibacterial properties using Pinus densiflora young cone extract.

    Science.gov (United States)

    Velmurugan, Palanivel; Park, Jung-Hee; Lee, Sang-Myeong; Jang, Jum-Suk; Lee, Kui-Jae; Han, Sang-Sub; Lee, Sang-Hyun; Cho, Min; Oh, Byung-Taek

    2015-06-01

    This study describes an eco-friendly, rapid method for green synthesis of silver nanoparticles (Ag NPs) from an aqueous solution of silver nitrate using Pinus densiflora for. multicaulis Uyeki young cone extract in a single-pot process. Color changes, ultraviolet-visible spectra (444.5 nm), X-ray diffraction peaks (2θ=39.68, 46.92, 68.12, and 79.10), and Fourier transform infrared spectroscopy (FT-IR) confirmed the presence of Ag NPs and phytochemicals. Transmission electron microscopy showed that the nanoparticles were mostly oval in shape, with a few triangular-shaped particles. Average particle size was 30-80 nm. Phytochemicals present in the young pine cone extract were likely responsible for the reduction of Ag(+) ions. The synthesized Ag NPs (40 μg) had a 7 mm larger zone of inhibition against the skin pathogen Brevibacterium linens than commercial Ag NPs, Propionibacterium acnes (14 mm), Bacillus cereus (9 mm) and Staphylococcus epidermidis (10mm).

  18. Bacterial flora concurrent with Helicobacter pylori in the stomach of patients with upper gastrointestinal diseases

    Institute of Scientific and Technical Information of China (English)

    Yuan Hu; Li-Hua He; Di Xiao; Guo-Dong Liu; Yi-Xin Gu; Xiao-Xia Tao; Jian-Zhong Zhang

    2012-01-01

    AIM:To investigate the non-Helicobacter pylori (H.pylorl) bacterial flora concurrent with H.py/ori infection.METHODS:A total of 103 gastric biopsy specimens from H.py/ori positive patients were selected for bacterial culture.All the non-H.py/ori bacterial isolates were identified by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS).RESULTS:A total of 201 non-H.py/ori bacterial isolates were cultivated from 67 (65.0%) of the 103 gastric samples,including 153 isolates identified successfully at species level and 48 at genus level by MALDI-TOF MS.The dominant species were Streptococcus,Neisseria,Rothia and Staphylococcus,which differed from the predominantly acid resistant species reported previously in healthy volunteers.The prevalence of non-H.pylori bacteria was higher in non-ulcer dyspepsia group than in gastric ulcer group (100% vs 42.9%,P < 0.001).Six bacterial species with urease activity (Staphylococcus epidermidis,Staphylococcus warneri,Staphylococcus capitis,Staphylococcus aureus,Brevibacterium spp.and Klebsiella pneumoniae) were also isolated.CONCLUSION:There is a high prevalence of the non-H.pylori bacteria concurrent with H.pylori infection,and the non-H.pylori bacteria may also play important as-yet-undiscovered roles in the pathogenesis of stomach disorders.

  19. Antioxidant Activity, Polyphenols Content and Antimicrobial Activity of Several Native Pteridophytes of Romania

    Directory of Open Access Journals (Sweden)

    Liliana Cristina SOARE

    2012-05-01

    Full Text Available The aim of this paper was to test the antioxidant activity, polyphenols content and antimicrobial activity of crude extracts obtained from leaves of pteridophyte species commonly found in Romania. The ORAC (Oxygen Radical Absorbance Capacity of the investigated ferns varied between 421.90 ?mol TE (Trolox equivalents/g FW (fresh weight in Dryopteris filix-mas and 128.18 ?mol TE/g FW in D. affinis. Methanolic extracts obtained from leaves of ferns have similar antioxidant activity to that of some medicinal plants. Polyphenols content in the leaves of ferns varies between 2340 mg Gallic acid equivalents (GAE/100 g FW in D. filix-mas and 887 mg GAE/100 g FW in D. affinis. The correlation coefficient between ORAC and the total polyphenol content was R=0.985. This correlation suggests that phenolic compounds are major contributors to the antioxidant activity. The methanolic extract obtained from ferns inhibits the growth of Gram negative Escherichia coli ATCC 25922, Pseudomonas aeruginosa NBJMCC1390, Salmonella abony and Gram positive Staphyllococcus aureus ATCC 25093 and Enterococcus faecalis. The highest antimicrobial activity was determined for the Dryopteris extract. The antimicrobial activity of methanolic extracts obtained from leaves of D. filix-mas and D. affinis is better than the A. filix-femina in the case of Brevibacterium flavum ATCC 14067, Sarcina sp., Bacillus cereus ATCC 1390, Saccharomyces cerevisiae and Aspergillus niger. The tested ferns could be used as cosmetic ingredients, as preservatives in food or in antimicrobial therapy.

  20. Entrapment of live microbial cells in electropolymerized polyaniline and their use as urea biosensor.

    Science.gov (United States)

    Jha, Sandeep Kumar; Kanungo, Mandakini; Nath, Archana; D'Souza, Stanislaus F

    2009-04-15

    The lyophilized biomass of bacterium Brevibacterium ammoniagenes was immobilized in polystyrene sulphonate-polyaniline (PSS-PANI) conducting polymer on a Pt twin wire electrode by potentiostatic electropolymerization. The bacterial cells retained their viability as well as urease activity under entrapped state, as confirmed with bacterial live-dead fluorescent assay and enzymatic assays. The entrapped cells were visualized using scanning electron microscope. The immobilized cells were used as a source of unpurified urease to develop a conductometric urea biosensor. The catalytic action of urease in the sensor released ammonia, thereby causing an increase in the pH of the microenvironment. The pH dependant change in the resistivity of the polymer was used as the basis of sensing mechanism. The sensor response was linear over a range of 0-75 mM urea with a sensitivity of 0.125 mM(-1). The sensor could be reused for 12-15 independent measurements and was quite stable in dry as well as buffered storage condition at 4 degrees C for at least 7 days.

  1. 牛乳中产耐高温蛋白酶嗜冷菌的分离及鉴定研究%Study on Isolation and Identification of Thermotolerant Protease-producing Psychrophiles in Milk

    Institute of Scientific and Technical Information of China (English)

    刘敏; 曹志军; 母智深; 李艳梅

    2009-01-01

    本实验采用单一性底物甲板分离法和Folin法,通过观察蛋白酶水解圈大小和测定该酶活力,从牛乳中共获得10株产耐高温蛋白酶的嗜冷菌.对菌体形态、染色反应、培养性状、生理生化性状进行系统研究.鉴定结果表明,上述10个细菌菌株分别属于气单胞菌属(Aeromonas)、巴斯德氏菌属(Pasteurella)、黄杆菌属(Flavobacterium)、变形菌属(Proteus)、节杆菌属(Arthrobacter)、短杆菌属(Brevibacterium)、微球菌属(Micrococcus)、片球菌属(Pediococcus)、乳球菌属(Lactococcus)和明串球菌属(Trichococcus).

  2. [Competitive Microbial Oxidation and Reduction of Arsenic].

    Science.gov (United States)

    Yang, Ting-ting; Bai, Yao-hui; Liang, Jin-song; Huo, Yang; Wang, Ming-xing; Yuan, Lin-ijang

    2016-02-15

    Filters are widely applied in drinking water treatment plants. Our previous study, which explored the asenic redox in a filter of drinking water plant treating underground water, found that As3+ could be oxidized to As5+ by biogenic manganese oxides, while As5+ could be reduced to As3+ by some microbial arsenic reductases in the biofilter system. This microbial competition could influence the system stability and treatment efficiency. To explore its mechanism, this study selected a manganese-oxidizing bacterial strain (Pseudomonas sp. QJX-1) and a arsenic-reducing strain (Brevibacterium sp. LSJ-9) to investigate their competitive relationship in nutrient acquisition and arsenic redox in the presence of Mn2+, As3+ or As5+ The results revealed that the concentration and valence of Mn and As varied with different reaction time; biological manganese oxides dominated the arsenic redox by rapidly oxidizing the As3+ in the existing system and the As3+ generated by arsenic reductase into As. PCR and RT-PCR results indicated that the arsenic reductase (arsC) was inhibited by the manganese oxidase (cumA). The expression of 16S rRNA in QJX-1 was two orders of magnitude higher than that in LSJ-9, which implied QJX-1 was dominant in the bacterial growth. Our data revealed that hydraulic retention time was critical to the valence of arsenic in the effluent of filter in drinking water treatment plant.

  3. PCR-denaturing gradient gel electrophoresis analysis of microbial community in soy-daddawa, a Nigerian fermented soybean (Glycine max (L.) Merr.) condiment.

    Science.gov (United States)

    Ezeokoli, Obinna T; Gupta, Arvind K; Mienie, Charlotte; Popoola, Temitope O S; Bezuidenhout, Cornelius C

    2016-03-02

    Soy-daddawa, a fermented soybean (Glycine max (L.) Merr.) condiment, plays a significant role in the culinary practice of West Africa. It is essential to understand the microbial community of soy-daddawa for a successful starter culture application. This study investigated the microbial community structure of soy-daddawa samples collected from Nigerian markets, by PCR-denaturing gradient gel electrophoresis (DGGE) targeting the V3-V5 region of the 16S rRNA gene of bacteria and internal transcribed spacer 2 (ITS2) region of fungi. Six bacterial and 16 fungal (nine yeasts and seven molds) operational taxonomic units (OTUs)/species were obtained at 97% sequence similarity. Taxonomic assignments revealed that bacterial OTUs belonged to the phyla Firmicutes and Actinobacteria, and included species from the genera Atopostipes, Bacillus, Brevibacterium and Nosocomiicoccus. Densitometric analysis of DGGE image/bands revealed that Bacillus spp. were the dominant OTU/species in terms of population numbers. Fungal OTUs belonged to the phyla Ascomycota and Zygomycota, and included species from the genera, Alternaria, Aspergillus, Candida, Cladosporium, Dokmaia, Issatchenkia, Kodamaea, Lecythophora, Phoma, Pichia, Rhizopus, Saccharomyces and Starmerella. The majority of fungal species have not been previously reported in soy-daddawa. Potential opportunistic human pathogens such as Atopostipes suicloacalis, Candida rugosa, Candida tropicalis, and Kodamaea ohmeri were detected. Variation in soy-daddawa microbial communities amongst samples and presence of potential opportunistic pathogens emphasises the need for starter culture employment and good handling practices in soy-daddawa processing.

  4. Combination of culture-independent and culture-dependent molecular methods for the determination of bacterial community of iru, a fermented Parkia biglobosa seeds.

    Science.gov (United States)

    Adewumi, Gbenga A; Oguntoyinbo, Folarin A; Keisam, Santosh; Romi, Wahengbam; Jeyaram, Kumaraswamy

    2012-01-01

    In this study, bacterial composition of iru produced by natural, uncontrolled fermentation of Parkia biglobosa seeds was assessed using culture-independent method in combination with culture-based genotypic typing techniques. PCR-denaturing gradient gel electrophoresis (DGGE) revealed similarity in DNA fragments with the two DNA extraction methods used and confirmed bacterial diversity in the 16 iru samples from different production regions. DNA sequencing of the highly variable V3 region of the 16S rRNA genes obtained from PCR-DGGE identified species related to Bacillus subtilis as consistent bacterial species in the fermented samples, while other major bands were identified as close relatives of Staphylococcus vitulinus, Morganella morganii, B. thuringiensis, S. saprophyticus, Tetragenococcus halophilus, Ureibacillus thermosphaericus, Brevibacillus parabrevis, Salinicoccus jeotgali, Brevibacterium sp. and uncultured bacteria clones. Bacillus species were cultured as potential starter cultures and clonal relationship of different isolates determined using amplified ribosomal DNA restriction analysis (ARDRA) combined with 16S-23S rRNA gene internal transcribed spacer (ITS) PCR amplification, restriction analysis (ITS-PCR-RFLP), and randomly amplified polymorphic DNA (RAPD-PCR). This further discriminated B. subtilis and its variants from food-borne pathogens such as B. cereus and suggested the need for development of controlled fermentation processes and good manufacturing practices (GMP) for iru production to achieve product consistency, safety quality, and improved shelf life.

  5. Combination of culture-independent and culture-dependent molecular methods for the determination of bacterial community of iru, a fermented Parkia biglobosa seeds.

    Directory of Open Access Journals (Sweden)

    Gbenga Adedeji Adewumi

    2013-01-01

    Full Text Available In this study, bacterial composition of iru produced by natural, uncontrolled fermentation of Parkia biglobosa seeds was assessed using culture-independent method in combination with culture-based genotypic typing techniques. PCR-denaturing gradient gel electrophoresis (DGGE revealed similarity in DNA fragments with the two DNA extraction methods used and confirmed bacterial diversity in the sixteen iru samples from different production regions. DNA sequencing of the highly variable V3 region of the 16S rRNA genes obtained from PCR-DGGE identified species related to Bacillus subtilis as consistent bacterial species in the fermented samples, while other major bands were identified as close relatives of Staphylococcus vitulinus, Morganella morganii, B. thuringiensis, Staphylococcus saprophyticus, Tetragenococcus halophilus, Ureibacillus thermosphaericus, Brevibacillus parabrevis, Salinicoccus jeotgali, Brevibacterium sp. and Uncultured bacteria clones. Bacillus species were cultured as potential starter cultures and clonal relationship of different isolates determined using amplified ribosomal DNA restriction analysis (ARDRA combined with 16S-23S rRNA gene internal transcribed spacer (ITS PCR amplification, restriction analysis (ITS-PCR-RFLP and randomly amplified polymorphic DNA (RAPD-PCR. This further discriminated Bacillus subtilis and its variants from food-borne pathogens such as Bacillus cereus and suggested the need for development of controlled fermentation processes and good manufacturing practices (GMP for iru production to achieve product consistency, safety quality and improved shelf life.

  6. Novel bacterial strains for the removal of microcystins from drinking water.

    Science.gov (United States)

    Lawton, L A; Welgamage, A; Manage, P M; Edwards, C

    2011-01-01

    Microcystins (MC) and nodularin (NOD) are common contaminants of drinking water around the world and due to their significant health impact it is important to explore suitable approaches for their removal. Unfortunately, these toxins are not always removed by conventional water treatments. One of the most exciting areas that hold promise for a successful and cost effective solution is bioremediation of microcystins. Recent work resulted in successful isolation and characterisation of 10 novel bacterial strains (Rhodococcus sp., Arthrobacter spp. and Brevibacterium sp.) capable of metabolizing microcystin-LR (MC-LR) in a Biolog MT2 assay. The work presented here aims to further investigate and evaluate the metabolism and the degradation of multiple microcystins (MC-LR, MC-LF, MC-LY, MC-LW and MC-RR) and nodularin by the bacterial isolates. A total of five bacterial isolates representing the three genera were evaluated using Biolog MT2 assay with a range of MCs where they all demonstrated an overall metabolism on all MCs and NOD. Subsequently, the results were confirmed by observing the degradation of the range of toxins in a separate batch experiment.

  7. 一株耐冷反硝化菌的分离鉴定及其反硝化特性%Identification and Denitrification Characteristics of a Strain of Psychrotrophic Denitrifying Bacteria

    Institute of Scientific and Technical Information of China (English)

    李军; 闫爽; 邓娴; 王立军; 张雅南; 杨宏宇

    2012-01-01

    A psychrotrophic denitrifying bacteria (designated Y2)with high efficiency degradation of nitrate nitrogen was isolated from the submerged mud in winter water at 151 which was used to treat high-nitrate wastewater at low temperature. According to the results of morphological observation,physiological and biochemical test .sequence analyses of the 16S rDNA, strain Y2 was identified as Brevibacterium. The NO," -N removal rate of Y2 can reach 51. 6% in denitrification medium at 151 in 3 days,and 99. 3% in 7 days. The optimum carbon source and the optimum nitrogen source of Y2 were sodium acetate and potassium nitrate. The suitable molar ratio of carbon/nitrogen for denitrification of the bacteria was 3= 1,the optimum pH value was 7.5, and the optimum temperature was 25 t. It showed Y2 was suitable for the nitrate elimination of ni-trates at low temperature.%目的 筛选分离出一株具有高效降解硝态氮的耐冷反硝化菌,以提高低温下硝酸盐废水处理的生物反硝化速率.方法 在15℃条件下从冬季淹水泥中分离纯化出一株耐冷反硝化细菌Y2,通过对该菌株的形态观察、生理生化试验以及16S rRNA序列分析,对菌株进行鉴定;通过批试验研究不同因素对菌株单位生物量脱氮率的影响.结果 初步确定Y2菌株为黄色短杆菌(Brevibacterium).该菌株能在15℃下在反硝化培养基中3d内对NO3- -N的去除率达到51.6%,7d能达到99.3%,该菌的最适碳源为乙酸钠、最适氮源为硝酸钾,最适碳氮比为3:1、最适pH值为7.5、最适温度25℃.结论 菌株Y2在低温下表现出良好的反硝化性能,NO3- -N质量浓度达300 mg/L时,去除率可达99.8%,适用于低温硝酸盐废水处理.

  8. Fermentation and recovery of L-glutamic acid from cassava starch hydrolysate by ion-exchange resin column Produção de ácido L-glutâmico a partir de um hidrolisado de amido de mandioca usando resina de troca iônica

    Directory of Open Access Journals (Sweden)

    K. Madhavan Nampoothiri

    1999-07-01

    Full Text Available Investigations were carried out with the aim of producing L-glutamic acid from Brevibacterium sp. by utilizing a locally available starchy substrate, cassava (Manihot esculenta Crantz. Initial studies were carried out in shake flasks, which showed that even though the yield was high with 85-90 DE (Dextrose Equivalent value, the maximum conversion yield (~34% was obtained by using only partially digested starch hydrolysate, i.e. 45-50 DE. Fermentations were carried out in batch mode in a 5 L fermenter, using suitably diluted cassava starch hydrolysate, using a 85-90 DE value hydrolysate. Media supplemented with nutrients resulted in an accumulation of 21 g/L glutamic acid with a fairly high (66.3% conversation yield of glucose to glutamic acid (based on glucose consumed and on 81.74% theoretical conversion rate. The bioreactor conditions most conducive for maximum production were pH 7.5, temperature 30°C and an agitation of 180 rpm. When fermentation was conducted in fed-batch mode by keeping the residual reducing sugar concentration at 5% w/v, 25.0 g/L of glutamate was obtained after 40 h fermentation (16% more the batch mode. Chromatographic separation by ion-exchange resin was used for the recovery and purification of glutamic acid. It was further crystallized and separated by making use of its low solubility at the isoelectric point (pH 3.2.Pesquisas foram realizadas com o objetivo de produzir ácido glutâmico a partir de Brevibacterium sp. utilizando um substrato disponível na região, a mandioca (Manihot esculenta Crantz. Estudos iniciais, desenvolvidos em shaker, demonstraram que mesmo obtendo elevado rendimento com 85-90 DE (Dextrose Equivalent value, a taxa de conversão máxima (~34% foi obtida usando um hidrolisado de amido parcialmente digerido, i.e. 45-50 DE. As fermentações foram realizadas em um fermentador de 5 L, usando um hidrolisado de amido de mandioca adequadamente diluído, preparado à partir de um valor DE de 85-90. O

  9. Polyphasic approach to characterize heterotrophic bacteria of biofilms and patina on walls of the Suburban Bath of the Herculaneum's archaeological excavations in Italy

    Science.gov (United States)

    Ventorino, V.; Pepe, O.; Sannino, L.; Blaiotta, G.; Palomba, S.

    2012-04-01

    plates were purified in the same growth medium by streaking and differentiated by assessing their morphological (phase-contrast microscopy) and biochemical characteristics (Gram-stains KOH-lysis and catalase activity). Cultural-based method allow us to identify by 16S and 26S rRNA partial sequence analysis, heterotrophic bacteria belonging to different genera as Bacillus, Pseudomonas, Aeromonas and Microbacterium. By using this approach, Bacillus-related species (B. benzoevorans, B. megaterium and B. pumilis and B. megaterium/B. simplex group) as well as Aeromonas sobria/Aeromonas salmonicida/Aeromonas hydrophila group, Pseudomonas plecoglossicida and Microbacterium esteraromaticum were isolated in different sample points analysed. DGGE analysis of PCR amplified V3 region of rDNA from DNA directly recovered from samples of biofilms and patina, enabled identification of bacterial species not found using culturable technology, as those closest related to Aeromonas, Paenibacillus, Brevibacterium, Exiguobacterium, Microbacterium, Brevibacterium, Stenothophomonas and Streptomyces. Combination of culture-dependent and independent methods provide a better characterization of heterotrophic microbiota that colonize the surface of ancient decorated walls and can contribute to understand the potential of biodeterioration activity by heterotrophic microorganisms.

  10. Diversidade e potencial biotecnológico da comunidade bacteriana endofítica de sementes de soja Diversity and biotechnological potential of endophytic bacterial community of soybean seeds

    Directory of Open Access Journals (Sweden)

    Laura de Castro Assumpção

    2009-05-01

    Full Text Available O objetivo deste trabalho foi isolar, caracterizar e identificar a comunidade bacteriana endofítica de sementes de soja e avaliar o seu potencial biotecnológico. Foram utilizadas sementes de 12 cultivares de soja. Os isolados bacterianos endofíticos obtidos foram avaliados in vitro quanto ao antagonismo a fungos fitopatogênicos, síntese de ácido indolacético (AIA e solubilização de fosfato. A caracterização foi realizada com técnicas de isolamento, análise de restrição do DNA ribossomal amplificado (ARDRA e sequenciamento parcial do gene 16S rDNA. Os isolados com maior potencial biotecnológico foram inoculados em sementes de soja, para se avaliar a capacidade de promoção de crescimento de plantas. Foi possível identificar 12 ribótipos por meio da ARDRA, que foram classificados como: Acinetobacter, Bacillus, Brevibacterium, Chryseobacterium, Citrobacter, Curtobacterium, Enterobacter, Methylobacterium, Microbacterium, Micromonospora, Pantoea, Paenibacillus, Pseudomonas, Ochrobactrum, Streptomyces e Tsukamurella. Quanto ao potencial biotecnológico da comunidade, 18% dos isolados controlaram o crescimento de fungos fitopatogênicos, 100% produziram AIA, e 39% solubilizaram fosfato. O isolado 67A(57 de Enterobacter sp. aumentou significativamente a massa de matéria seca da raiz. A inoculação de isolados com elevado potencial biotecnológico em avaliações in vitro não promoveu o crescimento de plantas de soja na maioria dos casos.The objectives of this work were to isolate, characterize and identify the endophytic bacterial community of soybean seeds, and to test the biotechnological potential of this community. Seeds from 12 soybean cultivars were used. The endophytic bacterial isolates were evaluated for in vitro antagonism against phytopathogenic fungi, synthesis of indoleacetic acid (IAA, and capacity to solubilize phosphate. Isolation techniques, amplified ribosomal DNA restriction analysis (ARDRA grouping, and

  11. 沉水植物轮叶黑藻附生细菌对双酚A的降解能力研究%Degradation of bisphenol A by the epiphytic bacteria of submerged macrophytes Hydrilla verticillata (L. f.) Royle

    Institute of Scientific and Technical Information of China (English)

    张国森; 王玉; 庄晓瑾; 杨劭; 蒋金辉

    2016-01-01

    Epiphytic bacteria of submerged macrophytes may have the capability in biodegradation and/or biotransformation of bisphenol A (BPA) in water column, therefore affect the fate of such environmental pollutant. In this research,Hydrilla verticillata(L. f.) Royle was selected and their attached BPA degrading epiphytic bacteria attached were isolated. Among the 22bacteria strains, the BPA removal rates were from 11.46% to 25.06% with the inoculum density at 1×10-8cell/mL and culture at 37℃ for 72h. The most effective bacteria strains, B12, B14and B23 were identified asLysinibacillus sp.,Brevibacterium sp. andOchrobactrum sp., respectively, according to the results of 16S rDNA sequencing and morphological, physiological and biochemical tests. But aseptic seedlings ofH. verticillata significantly decreased their BPA removal rates after the addition with B12, B14and B23 (P<0.05). Natural seedlings of such species surprisingly increased about 5% in BPA removal after partially removing their epiphyte with physical methods. All the results indicated that epiphytic bacteria of submerged plant can remove BPA, although their contributions (about 23%) are less than the host plants in the submerged macrophytes-epiphyte associations.%沉水植物附生细菌可能具有降解转化水体中双酚 A(BPA)能力从而影响该污染物在环境中的归趋.以轮叶黑藻为代表,分离筛选其BPA降解附生菌,结果共获得22株,在接种量为1×108个/mL,37℃下72h对BPA的去除率为11.46%~25.06%.选择降解率最高的3株细菌B12、B14和B23,采用16S rDNA鉴定,结合生理生化反应和形态观察,3株细菌分别为属于Lysinibacillus sp.(杆菌属),Brevibacterium sp.(短杆菌属)和Ochrobactrum sp.(苍白杆菌属).将3株菌株添加至轮叶黑藻无菌苗体系中,发现BPA去除率显著下降(P<0.05).物理去除部分野生轮叶黑藻表面部分附生细菌后,BPA去除率反而上升(约5%).综合本研究结果,沉水植物附生细菌具有降

  12. Contagem, isolamento e caracterização de bactérias psicrotróficas contaminantes de leite cru refrigerado Counting, isolation and characterization of psychrotrophic bacteria from refrigerated raw milk

    Directory of Open Access Journals (Sweden)

    Edna Froeder Arcuri

    2008-11-01

    Full Text Available Com os objetivos de quantificar, isolar e caracterizar bactérias psicrotróficas contaminantes de leite cru refrigerado, produzido na região da Zona da Mata de Minas Gerais e Sudeste do Rio de Janeiro, foram analisadas amostras de leite coletadas de 20 tanques coletivos e 23 tanques individuais. As contagens de bactérias psicrotróficas nas amostras de leite para os dois tipos de tanques de refrigeração variaram entre 10² e 10(7 Unidades Formadoras de Colônias (UFC ml-1, porém, um maior número de tanques coletivos apresentou contagens acima de 1 x 10(5 UFC ml-1. Foi verificada a predominância de bactérias psicrotróficas gram-negativas (81,2%, que foram identificadas pelos sistemas API 20E e API 20NE nos gêneros: Aeromonas, Alcaligenes, Acinetobacter, Burkholderia,Chryseomonas, Enterobacter, Ewingella, Klebsiella, Hafnia, Methylobacterium, Moraxella, Pantoea, Pseudomonas, Serratia, Sphingomonas e Yersinia. As bactérias gram-positivas (18,8% foram identificadas com API 50 CH, API Coryne e API Staph, nos gêneros: Bacillus, Brevibacterium, Cellum/Microbacterium, Kurthia e Staphylococcus. Os sistemas API utilizados não identificaram todos os isolados bacterianos. Pseudomonas foi o gênero mais isolado e P. fluorescens foi a espécie predominante. A maioria dos isolados bacterianos apresentou atividade proteolítica e/ou lipolítica a temperaturas de refrigeração de 4°C, 7°C e 10°C, evidenciando seu alto potencial de deterioração do leite e dos produtos lácteos. Os resultados ressaltam que maior atenção deve ser dada aos procedimentos que impeçam a contaminação do leite por esses microrganismos.This study aimed to quantify, isolate and characterize psychrotrophic bacteria from refrigerated raw milk produced at the ‘Mata’ Region of Minas Gerais State and Southeast of Rio de Janeiro State, Brazil. Raw milk samples, were collected at the farms, from 20 collective refrigerated tanks and 23 individual refrigerated tanks

  13. Bacterial Communities in Crude Oil Gathering and Transferring System%石油集输系统中微生物群落结构研究

    Institute of Scientific and Technical Information of China (English)

    刘永军; 郑昕; 金鹏康

    2009-01-01

    采用16S rRNA基因克隆-变性梯度凝胶电泳分析方法研究了石油集输系统原油和油田产水中的微生物群落结构.变性梯度凝胶电泳图谱显示:油田产水中微生物群落远比原油中的菌群丰富.所有的油田水样和原油样本中都存在与Ochrobactrum sp. 和Stenotrophomonas sp. 相关的细菌;原油样本中检测出与Burkholderia sp.、Brevundimonas sp.和Propionibacterium sp.相关的细菌,而这些细菌在油田水样中未检出;在油田水样中检出与Hippea sp.、Acidovorax sp.、Arcobacter sp.、Pseudomonas sp.、Thiomicrospira sp.、Brevibacterium sp.、Tissierella sp.和Peptostreptococcus sp.相关的细菌,而这些细菌在原油样本中未检出.用古细菌特异性引物进行检测发现在油田水样中存在与Methanomicrobials和Methanosarcinales相关的产甲烷菌,而这些细菌在原油样本中未检出.在石油集输过程中,油田水样和原油中微生物群落的相似性分别为83.3%和88.2%,说明微生物群落结构较为稳定.%Microbial community's structure of crude oil and oil field production water from an oil gathering and transferring system were studied adopting 16S rRNA gene cloning-denaturing gradient gel electrophoresis (DGGE) analysis. The atlas of DGGE showed that microbial communities in oilfield production water were far more richer than those in crude oil. All samples from oilfield production water and crude oil existed bacteria related to Ochrobacterium sp. and Stenotrophomonas sp. While samples from crude oil bacteria related to Burkholderia sp., Brevundimonas sp. and Propionibacterium sp. were detected, but none from oilfield production water samples. Bacteria related to Hippea sp., Acidovorax sp., Arcobacter sp., Pseudomonas sp., Thiomicrospira sp., Brevibacterium sp., Tissierella sp. and Peptostreptococcus sp. were detected from oilfield water samples, but none from crude oil samples. It were found Methanomicrobials and Methanosarcinales methane

  14. Identification and characterisation of oil sludge degrading bacteria isolated from compost

    Directory of Open Access Journals (Sweden)

    Ubani Onyedikachi

    2016-06-01

    Full Text Available Compounds present in oil sludge such as polycyclic aromatic hydrocarbons (PAHs are known to be cytotoxic, mutagenic and potentially carcinogenic. Microorganisms including bacteria and fungi have been reported to degrade oil sludge components to innocuous compounds such as carbon dioxide, water and salts. In the present study, we isolated different bacteria with PAH-degrading capabilities from compost prepared from oil sludge and animal manures. These bacteria were isolated on a mineral base medium and mineral salt agar plates. A total of 31 morphologically distinct isolates were carefully selected from 5 different compost treatments for identification using polymerase chain reaction (PCR of the 16S rRNA gene with specific primers (universal forward 16S-P1 PCR and reverse 16S-P2 PCR. The amplicons were sequenced and sequences were compared with the known nucleotides from the GenBank. The phylogenetic analyses of the isolates showed that they belong to 3 different clades; Firmicutes, Proteobacteria and Actinobacteria. These bacteria identified were closely related to the genera Bacillus, Arthrobacter, Staphylococcus, Brevibacterium, Variovorax, Paenibacillus, Ralstonia and Geobacillus. The results showed that Bacillus species were predominant in all composts. Based on the results of the degradation of the PAHs in the composts and results of previous studies on bacterial degradation of hydrocarbons in oil, the characteristics of these bacterial isolates suggests that they may be responsible for the breakdown of PAHs of different molecular weights in the composts. Thus, they may be potentially useful for bioremediation of oil sludge during compost bioremediation.

  15. 嗜铁细菌CAS17的分离鉴定及其对毒死蜱的降解特性研究%Isolation, identification and chlorpyrifos-degradation characteristics of siderophore producing bacterial strain CAS17

    Institute of Scientific and Technical Information of China (English)

    于婷; 董庆龙; 刘嘉芬; 安淼; 王海荣; 余贤美

    2014-01-01

    采用改良定向培育法,从获得的几株嗜铁细菌菌株中经过驯化筛选,获得1株对毒死蜱有较高降解作用的细菌CAS17.结合其生理生化特性及16SrRNA序列分析,将其鉴定为耐盐短杆菌(Brevibacterium halotolerans).生长特性和毒死蜱降解试验结果表明,该菌株对毒死蜱有较高的耐受性,在毒死蜱浓度达到800 mg·L-1时仍可生长.最适毒死蜱降解浓度为≤100 mg·L-1,降解率可达67%左右,浓度继续升高时降解效果明显降低;最适降解温度为30 ℃,对高温敏感;对pH值有着较强的适应范围,pH值在5~9之间的降解率波动不大;最适降解时间为48 h,振荡速率为150r·min-1,接种量为4%;适合其降解的最佳外加碳源为葡萄糖,最佳氮源为酵母粉,最佳无机盐为CaCl2.

  16. Plant growth promoting bacteria from Crocus sativus rhizosphere.

    Science.gov (United States)

    Ambardar, Sheetal; Vakhlu, Jyoti

    2013-12-01

    Present study deals with the isolation of rhizobacteria and selection of plant growth promoting bacteria from Crocus sativus (Saffron) rhizosphere during its flowering period (October-November). Bacterial load was compared between rhizosphere and bulk soil by counting CFU/gm of roots and soil respectively, and was found to be ~40 times more in rhizosphere. In total 100 bacterial isolates were selected randomly from rhizosphere and bulk soil (50 each) and screened for in-vitro and in vivo plant growth promoting properties. The randomly isolated bacteria were identified by microscopy, biochemical tests and sequence homology of V1-V3 region of 16S rRNA gene. Polyphasic identification categorized Saffron rhizobacteria and bulk soil bacteria into sixteen different bacterial species with Bacillus aryabhattai (WRF5-rhizosphere; WBF3, WBF4A and WBF4B-bulk soil) common to both rhizosphere as well as bulk soil. Pseudomonas sp. in rhizosphere and Bacillus and Brevibacterium sp. in the bulk soil were the predominant genera respectively. The isolated rhizobacteria were screened for plant growth promotion activity like phosphate solubilization, siderophore and indole acetic acid production. 50 % produced siderophore and 33 % were able to solubilize phosphate whereas all the rhizobacterial isolates produced indole acetic acid. The six potential PGPR showing in vitro activities were used in pot trial to check their efficacy in vivo. These bacteria consortia demonstrated in vivo PGP activity and can be used as PGPR in Saffron as biofertilizers.This is the first report on the isolation of rhizobacteria from the Saffron rhizosphere, screening for plant growth promoting bacteria and their effect on the growth of Saffron plant.

  17. Dynamics of bacterial communities during the ripening process of different Croatian cheese types derived from raw ewe's milk cheeses.

    Science.gov (United States)

    Fuka, Mirna Mrkonjić; Wallisch, Stefanie; Engel, Marion; Welzl, Gerhard; Havranek, Jasmina; Schloter, Michael

    2013-01-01

    Microbial communities play an important role in cheese ripening and determine the flavor and taste of different cheese types to a large extent. However, under adverse conditions human pathogens may colonize cheese samples during ripening and may thus cause severe outbreaks of diarrhoea and other diseases. Therefore in the present study we investigated the bacterial community structure of three raw ewe's milk cheese types, which are produced without the application of starter cultures during ripening from two production sites based on fingerprinting in combination with next generation sequencing of 16S rRNA gene amplicons. Overall a surprisingly high diversity was found in the analyzed samples and overall up to 213 OTU97 could be assigned. 20 of the major OTUs were present in all samples and include mostly lactic acid bacteria (LAB), mainly Lactococcus, and Enterococcus species. Abundance and diversity of these genera differed to a large extent between the 3 investigated cheese types and in response to the ripening process. Also a large number of non LAB genera could be identified based on phylogenetic alignments including mainly Enterobacteriaceae and Staphylococcacae. Some species belonging to these two families could be clearly assigned to species which are known as potential human pathogens like Staphylococcus saprophyticus or Salmonella spp. However, during cheese ripening their abundance was reduced. The bacterial genera, namely Lactobacillus, Streptococcus, Leuconostoc, Bifidobacterium, Brevibacterium, Corynebacterium, Clostridium, Staphylococcus, Thermoanerobacterium, E. coli, Hafnia, Pseudomonas, Janthinobacterium, Petrotoga, Kosmotoga, Megasphaera, Macrococcus, Mannheimia, Aerococcus, Vagococcus, Weissella and Pediococcus were identified at a relative low level and only in selected samples. Overall the microbial composition of the used milk and the management of the production units determined the bacterial community composition for all cheese types to a

  18. The Biosynthesis of Deuterium Labeled Amino Acids Using a Strain of Facultative Methylotrophic Bacterium Вrevibacterium Methylicum 5662 With RuMP Cycle of Carbon Assimilation

    Directory of Open Access Journals (Sweden)

    Oleg Mosin

    2015-03-01

    Full Text Available We used Gram-positive aerobic facultative methylotrophic bacterium, Brevibacterium methylicum, L-phenylalanine producer with ribulose-5-monophosphate (RuMP cycle for carbon assimilation for microbiological preparation of [2H]phenylalanine via conversion of low molecular weight substrates ([U-2H]MeOH and 2H2O. For this purpose, the cells of the methylotroph with improved growth characteristics were used on minimal salt media M9 supplemented with 2 % (v/v [U-2H]MeOH and increasing gradient of 2Н2O concentration from 0; 24,5; 49,0; 73,5 up to 98 % (v/v 2Н2O. L-phenylalanine was isolated from the growth medium after adding 5 M 2HCl (in 2Н2О, pH = 2,0 by extraction with isopropanol and subsequent crystallization in ethanol (output 0,65 g/l. Alanine, valine, and leucine/isoleucine were produced and accumulated exogenously in amounts of 5–6 mol in addition to the main product of biosynthesis. The method allows to obtain [2Н]amino acids with different levels of deuterium enrichment, depending on 2Н2O concentration in growth media, from 17 atom% 2Н (2 deuterium atoms (on the growth medium with 24,5 % (v/v 2Н2О up to 75 atom% 2Н (6 deuterium atoms (on the growth medium with 98 % (v/v 2Н2О with introduction of deuterium to benzyl С6Н5СН2-fragment of molecule that is confirmed with the data of electron impact (EI mass spectrometry analysis of methyl ethers of N-5-dimethylamino(naphthalene-1-sulfochloride [2H]amino acids after the separation by reverse-phase HPLC.

  19. Microbiological Synthesis of 2H-Labeled Phenylalanine, Alanine, Valine, and Leucine/Isoleucine with Different Degrees of Deuterium Enrichment by the Gram-Positive Facultative Methylotrophic Bacterium Вrevibacterium Methylicum

    Directory of Open Access Journals (Sweden)

    Oleg V. Mosin, PhD¹

    2013-06-01

    Full Text Available The microbiological synthesis of [2H]amino acids was performed by the conversion of low molecular weight substrates ([U-2H]MeOH and 2H2O using the Gram-positive aerobic facultative methylotrophic bacterium Brevibacterium methylicum, an L-phenylalanine producer, realizing the NAD+ dependent methanol dehydrogenase (EC 1.6.99.3 variant of the ribulose-5-monophosphate (RuMP cycle of carbon assimilation. In this process, the adapted cells of the methylotroph with enhanced growth characteristics were used on a minimal salt medium M9, supplemented with 2% (v/v [U-2H]MeOH and an increasing gradient of 2Н2O concentration from 0; 24.5, 49.0; 73.5 up to 98% (v/v 2Н2O. Alanine, valine, and leucine/isoleucine were produced and accumulated exogeneously in quantities of 5–6 mol, in addition to the main product of biosynthesis. This method enables the production of [2Н]amino acids with different degrees of deuterium enrichment, depending on the 2Н2O concentration in the growth medium, from 17 at.% 2Н (on the growth medium with 24.5 % (v/v 2Н2О up to 75 at.% 2Н (on the growth medium with 98 % (v/v 2Н2О. This has been confirmed with the data from the electron impact (EI mass spectrometry analysis of the methyl ethers of N-dimethylamino(naphthalene-5-sulfochloride [2H]amino acids under these experimental conditions.

  20. Use of the parallax-quench method to determine the position of the active-site loop of cholesterol oxidase in lipid bilayers.

    Science.gov (United States)

    Chen, X; Wolfgang, D E; Sampson, N S

    2000-11-07

    To elucidate the cholesterol oxidase-membrane bilayer interaction, a cysteine was introduced into the active site lid at position-81 using the Brevibacterium enzyme. To eliminate the possibility of labeling native cysteine, the single cysteine in the wild-type enzyme was mutated to a serine without any change in activity. The loop-cysteine mutant was then labeled with acrylodan, an environment-sensitive fluorescence probe. The fluorescence increased and blue-shifted upon binding to lipid vesicles, consistent with a change into a more hydrophobic, i.e., lipid, environment. This acrylodan-labeled cholesterol oxidase was used to explore the pH, ionic strength, and headgroup dependence of binding. Between pH 6 and 10, there was no significant change in binding affinity. Incorporation of anionic lipids (phosphatidylserine) into the vesicles did not increase the binding affinity nor did altering the ionic strength. These experiments suggested that the interactions are primarily driven by hydrophobic effects not ionic effects. Using vesicles doped with either 5-doxyl phosphatidylcholine, 10-doxyl phosphatidylcholine, or phosphatidyl-tempocholine, quenching of acrylodan fluorescence was observed upon binding. Using the parallax method of London [Chattopadhyay, A., and London, E. (1987) Biochemistry 26, 39-45], the acrylodan ring is calculated to be 8.1 +/- 2.5 A from the center of the lipid bilayer. Modeling the acrylodan-cysteine residue as an extended chain suggests that the backbone of the loop does not penetrate into the lipid bilayer but interacts with the headgroups, i.e., the choline. These results demonstrate that cholesterol oxidase interacts directly with the lipid bilayer and sits on the surface of the membrane.

  1. Structural Basis for Substrate and Oxygen Activation in Homoprotocatechuate 2,3-Dioxygenase: Roles of Conserved Active Site Histidine-200

    Science.gov (United States)

    Kovaleva, Elena G.; Rogers, Melanie S.; Lipscomb, John D.

    2015-01-01

    Kinetic and spectroscopic studies have shown that the conserved active site residue His200 of the extradiol ring-cleaving homoprotocatechuate 2,3-dioxygenase (FeHPCD) from Brevibacterium fuscum is critical for efficient catalysis. The roles played by this residue are probed here by analysis of the steady state kinetics, pH dependence, and X-ray crystal structures of the FeHPCD position 200 variants His200Asn, His200Gln, and His200Glu alone and in complex with three catecholic substrates (homoprotocatechuate, 4-sulfonylcatechol, and 4-nitrocatechol) possessing substituents with different inductive capacity. Structures solved at 1.35 –1.75 Å resolution show that there is essentially no change in overall active site architecture or substrate binding mode for these variants when compared to the structures of the wild type enzyme and its analogous complexes. This shows that the maximal 50-fold decrease in kcat for ring cleavage, the dramatic changes in pH dependence, and the switch from ring cleavage to ring oxidation of 4-nitrocatechol by the FeHPCD variants can be attributed specifically to the properties of the altered second sphere residue and the substrate. The results suggest that proton transfer is necessary for catalysis, and that it occurs most efficiently when the substrate provides the proton and His200 serves as a catalyst. However, in the absence of an available substrate proton, a defined proton-transfer pathway in the protein can be utilized. Changes in steric bulk and charge of the residue at position 200 appear capable of altering the rate-limiting step in catalysis, and perhaps, the nature of the reactive species. PMID:26267790

  2. Structural Basis for Substrate and Oxygen Activation in Homoprotocatechuate 2,3-Dioxygenase: Roles of Conserved Active Site Histidine 200.

    Science.gov (United States)

    Kovaleva, Elena G; Rogers, Melanie S; Lipscomb, John D

    2015-09-01

    Kinetic and spectroscopic studies have shown that the conserved active site residue His200 of the extradiol ring-cleaving homoprotocatechuate 2,3-dioxygenase (FeHPCD) from Brevibacterium fuscum is critical for efficient catalysis. The roles played by this residue are probed here by analysis of the steady-state kinetics, pH dependence, and X-ray crystal structures of the FeHPCD position 200 variants His200Asn, His200Gln, and His200Glu alone and in complex with three catecholic substrates (homoprotocatechuate, 4-sulfonylcatechol, and 4-nitrocatechol) possessing substituents with different inductive capacity. Structures determined at 1.35-1.75 Å resolution show that there is essentially no change in overall active site architecture or substrate binding mode for these variants when compared to the structures of the wild-type enzyme and its analogous complexes. This shows that the maximal 50-fold decrease in kcat for ring cleavage, the dramatic changes in pH dependence, and the switch from ring cleavage to ring oxidation of 4-nitrocatechol by the FeHPCD variants can be attributed specifically to the properties of the altered second-sphere residue and the substrate. The results suggest that proton transfer is necessary for catalysis, and that it occurs most efficiently when the substrate provides the proton and His200 serves as a catalyst. However, in the absence of an available substrate proton, a defined proton-transfer pathway in the protein can be utilized. Changes in the steric bulk and charge of the residue at position 200 appear to be capable of altering the rate-limiting step in catalysis and, perhaps, the nature of the reactive species.

  3. Exploring the diversity and antimicrobial potential of marine Actinobacteria from the Comau Fjord in Northern Patagonia, Chile

    Directory of Open Access Journals (Sweden)

    Agustina Undabarrena

    2016-07-01

    Full Text Available Bioprospecting natural products in marine bacteria from fjord environments are attractive due to their unique geographical features. Although Actinobacteria are well known for producing a myriad of bioactive compounds, investigations regarding fjord-derived marine Actinobacteria are scarce. In this study, the diversity and biotechnological potential of Actinobacteria isolated from marine sediments within the Comau fjord, in Northern Chilean Patagonia, were assessed by culture-based approaches. The 16S rRNA gene sequences revealed that members phylogenetically related to the Micrococcaceae, Dermabacteraceae, Brevibacteriaceae, Corynebacteriaceae, Microbacteriaceae, Dietziaceae, Nocardiaceae and Streptomycetaceae families were present at the Comau fjord. A high diversity of cultivable Actinobacteria (10 genera was retrieved by using only five different isolation media. Four isolates belonging to Arthrobacter, Brevibacterium, Corynebacterium and Kocuria genera showed 16S rRNA gene identity <98.7% suggesting that they are novel species. Physiological features such as salt tolerance, artificial sea water requirement, growth temperature, pigmentation and antimicrobial activity were evaluated. Arthrobacter, Brachybacterium, Curtobacterium, Rhodococcus and Streptomyces isolates showed strong inhibition against both Gram-negative Pseudomonas aeruginosa, Escherichia coli and Salmonella enterica and Gram-positive Staphylococcus aureus, Listeria monocytogenes. Antimicrobial activities in Brachybacterium, Curtobacterium and Rhodococcus have been scarcely reported, suggesting that non-mycelial strains are a suitable source of bioactive compounds. In addition, all strains bear at least one of the biosynthetic genes coding for NRPS (91%, PKS I (18% and PKS II (73%.Our results indicate that the Comau fjord is a promising source of novel Actinobacteria with biotechnological potential for producing biologically active compounds.

  4. [Microbiological analysis of terrestrial biotopes of the Antarctic region].

    Science.gov (United States)

    Tashirev, A B; Romanovskaia, V A; Rokitko, P V; Shilin, S O; Chernaia, N A; Tashireva, A A

    2010-01-01

    Microbiological analysis has been made of 120 samples from biotopes of the western coast of the Antarctic peninsula (Rasmussen cope, Tuxen cope, Waugh mountain), Argentine archipelago islands (Galindez, Skua, Corner, Barchans, Irizar, Uruguay, Cluls, Three Little Pigs, King-George), as well as neighbouring islands (Petermann--on the north, a group of Jalour islands--on the east, Berthelot--on the south-east); and more remote islands (Darboux, Lippmann, Booth). It was found out that the total number of chemoorganotrophic aerobic microorganisms was 10(6) - 10(8) cells/g of soil, that was by 2-3 orders lower than in the regions with temperate climate. One can observe a tendency of decreasing the quantity of chemoorganotrophic microorganisms in the Antartic biotopes (cells/g of a sample) in the following order: soil (1 x 10(7) - 8 x 10(8)), underground part of moss (1 x 10(6) - 5 x 10(7)), grass Deschampsia antarctica (10(6) - 10(8), slit of fresh-water reservoir (10(5) - 10(7)), ground part of moss (10(3) - 10(6)), lichens (10(3) - 10(6)). Representatives of several phylogenetic lines: Proteobacteria (genera Pseudomonas, Methylobacterium, Enterobacter), Firmicutes (genera Bacillus, Staphylococcus), Actinobacteria (genera Brevibacterium, Actinomyces, Streptomyces) have been found in the Antarctic samples. As a rule, genera of bacteria found in the Antarctic Region are widely distributed in different regions of the Earth with temperate climate. Microorganisms similar to the species Exophiala nigra (Issatsch.) Haats et de Hoog 1999, which was first detected 100 years ago by Academician B.L. Isachenko in the Arctic region water, were also isolated from biofilms on vertical rocks of the Galindez Island as well as from the soil of the Irizar Island.

  5. Increase in Bacterial Colony Formation from a Permafrost Ice Wedge Dosed with a Tomitella biformata Recombinant Resuscitation-Promoting Factor Protein.

    Science.gov (United States)

    Puspita, Indun Dewi; Kitagawa, Wataru; Kamagata, Yoichi; Tanaka, Michiko; Nakatsu, Cindy H

    2015-01-01

    Resuscitation-promoting factor (Rpf) is a protein that has been found in a number of different Actinobacteria species and has been shown to promote the growth of active cells and resuscitate dormant (non-dividing) cells. We previously reported the biological activity of an Rpf protein in Tomitella biformata AHU 1821(T), an Actinobacteria isolated from a permafrost ice wedge. This protein is excreted outside the cell; however, few studies have investigated its contribution in environmental samples to the growth or resuscitation of bacteria other than the original host. Therefore, the aim of the present study was to determine whether Rpf from T. biformata impacted the cultivation of other bacteria from the permafrost ice wedge from which it was originally isolated. All experiments used recombinant Rpf proteins produced using a Rhodococcus erythropolis expression system. Dilutions of melted surface sterilized ice wedge samples mixed with different doses of the purified recombinant Rpf (rRpf) protein indicated that the highest concentration tested, 1250 pM, had a significantly (p <0.05) higher number of CFUs on agar plates after 8 d, approximately 14-fold higher than that on control plates without rRpf. 16S rRNA gene sequences revealed that all the colonies on plates were mainly related to Brevibacterium antiquum strain VKM Ac-2118 (AY243344), with 98-99% sequence identity. This species is also a member of the phylum Actinobacteria and was originally isolated from Siberian permafrost sediments. The results of the present study demonstrated that rRpf not only promoted the growth of T. biformata from which it was isolated, but also enhanced colony formation by another Actinobacteria in an environmental sample.

  6. Phosphate Solubilizing Ability and Phylogenetic Diversity of Bacteria from P-Rich Soils Around Dianchi Lake Drainage Area of China

    Institute of Scientific and Technical Information of China (English)

    YANG Pei-Xiang; YANG Fa-Xiang; MA Li; CHEN Ming-Hui; XI Jia-Qin; HE Feng; DUAN Chang-Qun; MO Ming-He; FANG Dun-Huang; DUAN Yan-Qing

    2012-01-01

    The phylogenetic diversity of phosphate solubilizing bacteria (PSB) distributed in P-rich soils in the Dianchi Lake drainage area of China was characterized,and the tricalcium phosphate (TCP) solubilizing activities of isolated PSB were determined.Among 1328 bacteria isolated from 100 P-rich soil samples,377 isolates (28.39% of the total) that exhibited TCP solubilization activity were taken as PSB.These PSB showed different abilities to solubilize TCP,with the concentrations of solubilized P in bacterial cultures varying from 33.48 to 69.63 mg L -1.A total of 123 PSB isolates,with relatively high TCP solubilization activity (> 54.00mg L-1),were submitted for restriction fragment length polymorphism (RFLP) analysis,which revealed 32 unique RFLP patterns.Based on these patterns,62 representative isolates,one to three from each RFLP pattern,were selected for 16S rRNA sequencing Phylogenetic analysis placed the 123 PSB into three bacterial phyla,namely proteobacteria,Actinobacteria and Firrnicutes.Members of proteobacteria were the dominant PSB,where 107 isolates represented by 26 RFLP patterns were associated with the genera of Burkholdema,Pseudomonas,Acinetobacter,Enterobacter,Pantoea,Serratia,Klebsiella,Leclercia,Raoultella and Cedecea.Firmicutes were the subdominant group,in which 13 isolates were affiliated with the genera of Bacillus and Brevibacterium.The remaining 3 isolates were identified as three species of the genus Arthrobacter.This research extends the knowledge on PSB in P-rich soils and broadens the spectrum of PSB for the development of environmentally friendly biophosphate fertilizers.

  7. Pyrethroid-Degrading Microorganisms and Their Potential for the Bioremediation of Contaminated Soils: A Review

    Directory of Open Access Journals (Sweden)

    Mariusz Sebastian Cycoń

    2016-09-01

    Full Text Available Pyrethroid insecticides have been used to control pests in agriculture, forestry, horticulture, public health and for indoor home use for more than 20 years. Because pyrethroids were considered to be a safer alternative to organophosphate pesticides (OPs, their applications significantly increased when the use of OPs was banned or limited. Although pyrethroids have agricultural benefits, their widespread and continuous use is a major problem as they pollute the terrestrial and aquatic environments and affect non-target organisms. Since pyrethroids are not degraded immediately after application and because their residues are detected in soils, there is an urgent need to remediate pyrethroid-polluted environments. Various remediation technologies have been developed for this purpose; however, bioremediation, which involves bioaugmentation and/or biostimulation and is a cost-effective and eco-friendly approach, has emerged as the most advantageous method for cleaning-up pesticide-contaminated soils. This review presents an overview of the microorganisms that have been isolated from pyrethroid-polluted sites, characterized and applied for the degradation of pyrethroids in liquid and soil media. The paper is focused on the microbial degradation of the pyrethroids that have been most commonly used for many years such as allethrin, bifenthrin, cyfluthrin, cyhalothrin, cypermethrin, deltamethrin, fenpropathrin, fenvalerate and permethrin. Special attention is given to the bacterial strains from the genera Achromobacter, Acidomonas, Bacillus, Brevibacterium, Catellibacterium, Clostridium, Lysinibacillus, Micrococcus, Ochrobactrum, Pseudomonas, Serratia, Sphingobium, Streptomyces and the fungal strains from the genera Aspergillus, Candida, Cladosporium and Trichoderma, which are characterized by their ability to degrade various pyrethroids. Moreover, the current knowledge on the degradation pathways of pyrethroids, the enzymes that are involved in the

  8. Accumulation of Rare Earth Elements in Various Microorganisms

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The removal of rare earth elements (REEs) from solution in various microorganisms was examined. Seventy-six strains from 69 species (22 bacteria, 20 actinomycetes, 18 fungi, and 16 yeasts) were tested. Initially, Sm was used to test the removal capabilities of the various organisms. Gram-positive bacteria, such as Bacillus licheniformis, B. subtilis, Brevibacterium helovolum, and Rhodococcus elythropolis, exhibited a particularly high capacity for accumulating Sm. In particular, the B. lichemiformis cells accumulated approximately 316 μmol Sm per gram dry wt. of microbial cells. A full suite of screenings was then conducted to compare the abilities of the organisms to remove Sc, Y, La, Er, and, Lu from solution. Tests were done with solutions containing one REE at a time. Accumulation was nearly identical for the various metals and organisms. However, when solutions with equimolar amounts of two REEs were used, preferential removal from solution was observed. When an Eu/Gd solution was used, gram-positive bacteria removed more Eu and Gd as compared to actinomycetes. When Eu/Sm combination was used, gram-positive bacteria removed equal mounts of both metals and some actinomycetes removed more Eu. The selective removal was quantified by calculating separation factors (S. F.), which indicated that Streptomyces levoris cells accumulated the greatest proportion of Eu. The removal of REEs from a solution containing five metals (Y, La, Sm, Er, and Lu) was then examined. Mucor javanicus preferentially accumulated Sm and S. flavoviridis preferentially accumulated Lu. The effects of pH and Sm concentration on the accumulation of Sm by B. licheniformis were also examined. Accumulation increased at higher pH and at greater solution concentrations.

  9. Bacterial diversity in spent mushroom compost assessed by amplified rDNA restriction analysis and sequencing of cultivated isolates.

    Science.gov (United States)

    Ntougias, Spyridon; Zervakis, Georgios I; Kavroulakis, Nektarios; Ehaliotis, Constantinos; Papadopoulou, Kalliope K

    2004-11-01

    Spent mushroom compost (SMC) is the residual by-product of commercial Agaricus spp. cultivation, and it is mainly composed of a thermally treated cereal straw/animal manure mixture colonized by the fungal biomass. Research on the valorization of this material is mainly focusing on its use as soil conditioner and plant fertilizer. An investigation of the bacterial diversity in SMC was performed using molecular techniques in order to reveal the origin of SMC microflora and its potential effect on soil microbial communities after incorporation into agricultural soils. The bacterial population was estimated by the plate count method to a mean of 2.7 10(9) colony forming units (cfu) per g of dry weight, while the numbers of Gram-positive and Gram-negative bacteria were 1.9 10(9) and 4.9 10(8) cfu per g dw respectively as estimated by enumeration on semi-selective media. Fifty bacterial isolates were classified into 14 operational taxonomic units (OTUs) following ARDRA-PCR of the 16S rDNA gene. Sequencing of the 16S rDNA amplicon assigned 12 of the 14 OTUs to Gram-positive bacteria, associated with the genera Bacillus, Paenibacillus, Exiguobacterium, Staphylococcus, Desemzia, Carnobacterium, Brevibacterium, Arthrobacter and Microbacterium of the bacterial divisions Firmicutes and Actinobacteria. Two bacterial groups have phylogenetic links with the genera Comamonas and Sphingobacterium, which belong to beta-Proteobacteria and Bacteroidetes respectively. Two potentially novel bacteria are reported, which are associated with the genera Bacillus and Microbacterium. Most of the bacteria identified are of environmental origin, while strains related to species usually isolated from insects, animal and clinical sources were also detected. It appears that bacterial diversity in SMC is greatly affected by the origin of the initial material, its thermal pasteurization treatment and the potential unintended colonization of the mushroom substrate during the cultivation process.

  10. 宜宾芽菜低盐腌渍工艺研究%Study on the Low-salt Pickling Technology of Yibin Sprouts

    Institute of Scientific and Technical Information of China (English)

    尹礼国; 庄婷; 凌跃; 游玲; 王松; 徐洲; 张超

    2015-01-01

    从宜宾芽菜腌渍产品中筛选到5株产酸能力强的乳酸菌,降亚硝酸盐能力均在90%以上.通过16S rDNA分子生物学鉴定初步确定LAB-YC-2为Bacillus tequilensis,LAB-YC-8,LBA-YC-23为Brevibacterium halotolerans,LAB-YC-22,LAB-YC-28为Bacillus subtilis subsp.subtilis.LAB-Yc28较其他4株菌更适于制作低盐芽菜.研究确定芽菜低盐腌渍工艺条件是在25℃条件下,接种5%的以LAB-YC-28制作的发酵剂,腌渍6天,添加6%的食盐,腌渍产品色泽鲜艳,香气纯正,脆嫩可口,pH值为3.46~3.64,总酸度(以乳酸计)为0.75%±0.08%,亚硝酸盐含量为(1.528士0.122)mg/kg.低盐腌渍工艺是降低工厂废水排放量,减少人体食盐撮入量的有效措施.

  11. Pyrethroid-Degrading Microorganisms and Their Potential for the Bioremediation of Contaminated Soils: A Review

    Science.gov (United States)

    Cycoń, Mariusz; Piotrowska-Seget, Zofia

    2016-01-01

    Pyrethroid insecticides have been used to control pests in agriculture, forestry, horticulture, public health and for indoor home use for more than 20 years. Because pyrethroids were considered to be a safer alternative to organophosphate pesticides (OPs), their applications significantly increased when the use of OPs was banned or limited. Although, pyrethroids have agricultural benefits, their widespread and continuous use is a major problem as they pollute the terrestrial and aquatic environments and affect non-target organisms. Since pyrethroids are not degraded immediately after application and because their residues are detected in soils, there is an urgent need to remediate pyrethroid-polluted environments. Various remediation technologies have been developed for this purpose; however, bioremediation, which involves bioaugmentation and/or biostimulation and is a cost-effective and eco-friendly approach, has emerged as the most advantageous method for cleaning-up pesticide-contaminated soils. This review presents an overview of the microorganisms that have been isolated from pyrethroid-polluted sites, characterized and applied for the degradation of pyrethroids in liquid and soil media. The paper is focused on the microbial degradation of the pyrethroids that have been most commonly used for many years such as allethrin, bifenthrin, cyfluthrin, cyhalothrin, cypermethrin, deltamethrin, fenpropathrin, fenvalerate, and permethrin. Special attention is given to the bacterial strains from the genera Achromobacter, Acidomonas, Bacillus, Brevibacterium, Catellibacterium, Clostridium, Lysinibacillus, Micrococcus, Ochrobactrum, Pseudomonas, Serratia, Sphingobium, Streptomyces, and the fungal strains from the genera Aspergillus, Candida, Cladosporium, and Trichoderma, which are characterized by their ability to degrade various pyrethroids. Moreover, the current knowledge on the degradation pathways of pyrethroids, the enzymes that are involved in the cleavage of

  12. Histamine and tyramine degradation by food fermenting microorganisms.

    Science.gov (United States)

    Leuschner, R G; Heidel, M; Hammes, W P

    1998-01-06

    Microorganisms suitable for food fermentation were examined with regard to their potential to degrade histamine and tyramine. Out of 64 lactic acid bacteria evaluated in this study, 27 degraded histamine and one tyramine, respectively, with low activity. Among 32 strains of Brevibacterium linens and coryneform bacteria, 21 exhibited histamine and tyramine oxidase activity. None of 20 strains of Staphylococcus carnosus tested degraded histamine or tyramine. One strain out of nine strains of Geotrichum candidum degraded tyramine slightly. Among 44 strains of Micrococcus sp. examined, 17 degraded either one or two biogenic amines. In this study Micrococcus varians (M. varians) LTH 1540 exhibited the highest tyramine oxidase activity of all strains tested and was therefore investigated in detail. The enzyme was found to be located in the cytoplasm and was not membrane bound. The reaction end product p-hydroxyphenyl acetic acid was detected by HPLC analysis. An activity staining for the amine oxidase in a native polyacrylamide gel based on the formation of H2O2 during amine oxidation was developed. Resting cells of the strain exhibited optimal tyramine oxidase activity at a pH of 7 at 37-40 degrees C. The enzyme in the cell free extract had a pH optimum between 7-8. The enzyme activity was decreased by NaCl, glucose and hydralazine. Phenylethylamine and tryptamine were oxidized at lower concentrations than tyramine. The potential for amine degradation was not found to be associated with that of formation of biogenic amines, as 23 microorganisms with the ability to metabolise biogenic amines exhibited no decarboxylase activity toward histidine, tyrosine, phenylalanine, lysine or ornithine.

  13. Exploring the Diversity and Antimicrobial Potential of Marine Actinobacteria from the Comau Fjord in Northern Patagonia, Chile

    Science.gov (United States)

    Undabarrena, Agustina; Beltrametti, Fabrizio; Claverías, Fernanda P.; González, Myriam; Moore, Edward R. B.; Seeger, Michael; Cámara, Beatriz

    2016-01-01

    Bioprospecting natural products in marine bacteria from fjord environments are attractive due to their unique geographical features. Although, Actinobacteria are well known for producing a myriad of bioactive compounds, investigations regarding fjord-derived marine Actinobacteria are scarce. In this study, the diversity and biotechnological potential of Actinobacteria isolated from marine sediments within the Comau fjord, in Northern Chilean Patagonia, were assessed by culture-based approaches. The 16S rRNA gene sequences revealed that members phylogenetically related to the Micrococcaceae, Dermabacteraceae, Brevibacteriaceae, Corynebacteriaceae, Microbacteriaceae, Dietziaceae, Nocardiaceae, and Streptomycetaceae families were present at the Comau fjord. A high diversity of cultivable Actinobacteria (10 genera) was retrieved by using only five different isolation media. Four isolates belonging to Arthrobacter, Brevibacterium, Corynebacterium and Kocuria genera showed 16S rRNA gene identity <98.7% suggesting that they are novel species. Physiological features such as salt tolerance, artificial sea water requirement, growth temperature, pigmentation and antimicrobial activity were evaluated. Arthrobacter, Brachybacterium, Curtobacterium, Rhodococcus, and Streptomyces isolates showed strong inhibition against both Gram-negative Pseudomonas aeruginosa, Escherichia coli and Salmonella enterica and Gram-positive Staphylococcus aureus, Listeria monocytogenes. Antimicrobial activities in Brachybacterium, Curtobacterium, and Rhodococcus have been scarcely reported, suggesting that non-mycelial strains are a suitable source of bioactive compounds. In addition, all strains bear at least one of the biosynthetic genes coding for NRPS (91%), PKS I (18%), and PKS II (73%). Our results indicate that the Comau fjord is a promising source of novel Actinobacteria with biotechnological potential for producing biologically active compounds. PMID:27486455

  14. L-methionine degradation potentialities of cheese-ripening microorganisms.

    Science.gov (United States)

    Bonnarme, P; Lapadatescu, C; Yvon, M; Spinnler, H E

    2001-11-01

    Volatile sulphur compounds are major flavouring compounds in many traditional fermented foods including cheeses. These compounds are products of the catabolism of L-methionine by cheese-ripening microorganisms. The diversity of L-methionine degradation by such microorganisms, however, remains to be characterized. The objective of this work was to compare the capacities to produce volatile sulphur compounds by five yeasts, Geotrichum candidum, Yarrowia lipolytica, Kluyveromyces lactis, Debaryomyces hansenii, Saccharomyces cerevisiae and five bacteria, Brevibacterium linens, Corynebacterium glutamicum, Arthrobacter sp., Micrococcus lutens and Staphylococcus equorum of technological interest for cheese-ripening. The ability of whole cells of these microorganisms to generate volatile sulphur compounds from L-methionine was compared. The microorganisms produced a wide spectrum of sulphur compounds including methanethiol, dimethylsulfide, dimethyldisulfide, dimethyltrisulfide and also S-methylthioesters, which varied in amount and type according to strain. Most of the yeasts produced methanethiol, dimethylsulfide, dimethyldisulfide and dimethyltrisulfide but did not produce S-methylthioesters, apart from G. candidum that produced S-methyl thioacetate. Bacteria, especially Arth. sp. and Brevi. linens, produced the highest amounts and the greatest variety of volatile sulphur compounds includling methanethiol, sulfides and S-methylthioesters, e.g. S-methyl thioacetate, S-methyl thiobutyrate, S-methyl thiopropionate and S-methyl thioisovalerate. Cell-free extracts of all the yeasts and bacteria were examined for the activity of enzymes possibly involved in L-methionine catabolism, i.e. L-methionine demethiolase, L-methionine aminotransferase and L-methionine deaminase. They all possessed L-methionine demethiolase activity, while some (K. lactis, Deb. hansenii, Arth. sp., Staph. equorum) were deficient in L-methionine aminotransferase, and none produced L-methionine deaminase

  15. Microbial diversity and dynamics throughout manufacturing and ripening of surface ripened semi-hard Danish Danbo cheeses investigated by culture-independent techniques.

    Science.gov (United States)

    Ryssel, Mia; Johansen, Pernille; Al-Soud, Waleed Abu; Sørensen, Søren; Arneborg, Nils; Jespersen, Lene

    2015-12-23

    Microbial successions on the surface and in the interior of surface ripened semi-hard Danish Danbo cheeses were investigated by culture-dependent and -independent techniques. Culture-independent detection of microorganisms was obtained by denaturing gradient gel electrophoresis (DGGE) and pyrosequencing, using amplicons of 16S and 26S rRNA genes for prokaryotes and eukaryotes, respectively. With minor exceptions, the results from the culture-independent analyses correlated to the culture-dependent plating results. Even though the predominant microorganisms detected with the two culture-independent techniques correlated, a higher number of genera were detected by pyrosequencing compared to DGGE. Additionally, minor parts of the microbiota, i.e. comprising cheeses diverged. During cheese production pyrosequencing determined Lactococcus as the dominating genus on cheese surfaces, representing on average 94.7%±2.1% of the OTUs. At day 6 Lactococcus spp. declined to 10.0% of the OTUs, whereas Staphylococcus spp. went from 0.0% during cheese production to 75.5% of the OTUs at smearing. During ripening, i.e. from 4 to 18 weeks, Corynebacterium was the dominant genus on the cheese surface (55.1%±9.8% of the OTUs), with Staphylococcus (17.9%±11.2% of the OTUs) and Brevibacterium (10.4%±8.3% of the OTUs) being the second and third most abundant genera. Other detected bacterial genera included Clostridiisalibacter (5.0%±4.0% of the OTUs), as well as Pseudoclavibacter, Alkalibacterium and Marinilactibacillus, which represented cheeses was dominated by Lactococcus spp. comprising on average 93.9%±7.8% of the OTUs throughout the cheese processing. The microbial dynamics described at genus level in this study add to a comprehensive understanding of the complex microbiota existing especially on surface ripened semi-hard cheeses.

  16. Commercial ripening starter microorganisms inoculated into cheese milk do not successfully establish themselves in the resident microbial ripening consortia of a South german red smear cheese.

    Science.gov (United States)

    Goerges, Stefanie; Mounier, Jérôme; Rea, Mary C; Gelsomino, Roberto; Heise, Valeska; Beduhn, Rüdiger; Cogan, Timothy M; Vancanneyt, Marc; Scherer, Siegfried

    2008-04-01

    Production of smear-ripened cheese critically depends on the surface growth of multispecies microbial consortia comprising bacteria and yeasts. These microorganisms often originate from the cheese-making facility and, over many years, have developed into rather stable, dairy-specific associations. While commercial smear starters are frequently used, it is unclear to what degree these are able to establish successfully within the resident microbial consortia. Thus, the fate of the smear starters of a German Limburger cheese subjected to the "old-young" smearing technique was investigated during ripening. The cheese milk was supplemented with a commercial smear starter culture containing Debaryomyces hansenii, Galactomyces geotrichum, Arthrobacter arilaitensis, and Brevibacterium aurantiacum. Additionally, the cheese surface was inoculated with an extremely stable in-house microbial consortium. A total of 1,114 yeast and 1,201 bacterial isolates were identified and differentiated by Fourier transform infrared spectroscopy. Furthermore, mitochondrial DNA restriction fragment length polymorphism, random amplified polymorphic DNA, repetitive PCR, and pulsed field gel electrophoresis analyses were used to type selected isolates below the species level. The D. hansenii starter strain was primarily found early in the ripening process. The G. geotrichum starter strain in particular established itself after relocation to a new ripening room. Otherwise, it occurred at low frequencies. The bacterial smear starters could not be reisolated from the cheese surface at all. It is concluded that none of the smear starter strains were able to compete significantly and in a stable fashion against the resident microbial consortia, a result which might have been linked to the method of application. This finding raises the issue of whether addition of starter microorganisms during production of this type of cheese is actually necessary.

  17. 冷海水保藏下鲐鱼(Pneumatophorus japonicus)菌相变化规律及优势腐败菌的分离鉴定%Microflora Composition Variation in Mackerel (Pneumatophorus japonicas) Stored in Refrigerated Seawater, and Isolation and Identification of the Dominant Spoilage Bacteria

    Institute of Scientific and Technical Information of China (English)

    郑振霄; 周聃; 冯俊丽; 金仁耀; 戴志远

    2016-01-01

    以冷海水保鲜的鲐鱼为研究对象,通过选择性生培养基和16S rDNA序列分析法探究其在冷海水保鲜过程中的菌相变化,确定了鲐鱼在冷海水保鲜条件下的优势腐败菌,并通过MEGA5.2软件构建了贮藏末期代表菌株的系统发育树.结果表明:冷海水保鲜鲐鱼样品在贮藏初期(第0d)的微生物比较复杂,优势种群是假单胞菌属(Pseudomonas sp.)和嗜冷菌属(Psychrobacter sp.),还有少量的类芽孢杆菌属(Paenibacillus sp.)、希瓦氏菌属(Shewanella sp.)、蜡状芽孢杆菌(Bacillus anthracis)、枯草芽孢杆菌属(Brevibacterium sp.);随着贮藏时间的延长,鲐鱼样品中的菌相逐渐变的单一,假单胞菌属迅速下降,希瓦氏菌属迅速增加;贮藏末期希瓦氏菌属和肠杆菌属(Enterobacter sp.)的比例迅速增加,其中希瓦氏菌属呈上升趋势且到贮藏后期数量占绝对优势,被确定为鲐鱼冷海水保鲜条件下的优势腐败菌.

  18. Bacterial diversity in Amblyomma americanum (Acari: Ixodidae) with a focus on members of the genus Rickettsia.

    Science.gov (United States)

    Heise, Stephanie R; Elshahed, M S; Little, S E

    2010-03-01

    The lone star tick, Amblyomma americanum (Acari: Ixodidae), is commonly reported from people and animals throughout the eastern U.S. and is associated with transmission of a number of emerging diseases. To better define the microbial communities within lone star ticks, 16S rRNA gene based analysis using bacteria-wide primers, followed by sequencing of individual clones (n = 449) was used to identify the most common bacterial operational taxonomic units (OTUs) present within colony-reared and wild A. americanum. The colony-reared ticks contained primarily sequence affiliated with members of the genus Coxiella (89%; 81/91), common endosymbionts of ticks, and Brevibacterium (11%; 10/91). Similarly, analysis of clones from unfed wild lone star ticks revealed that 96.7% (89/92) of all the OTUs identified were affiliated with Coxiella-like endosymbionts, as compared with only 5.1-11.7% (5/98-9/77) of those identified from wild lone star ticks after feeding. In contrast, the proportion of OTUs identified as Rickettsia sp. in wild-caught ticks increased from 2.2% (2/92) before feeding to as high as 46.8% (36/77) after feeding, and all Rickettsia spp. sequences recovered were most similar to those described from the spotted fever group Rickettsia, specifically R. amblyommii and R. massiliae. Additional characterization of the Rickettsiales tick community by polymerase chain reaction, cloning, and sequencing of 17 kDa and gltA genes confirmed these initial findings and suggested that novel Rickettsia spp. are likely present in these ticks. These data provide insight into the overall, as well as the rickettsial community of wild lone star ticks and may ultimately aid in identification of novel pathogens transmitted by A. americanum.

  19. Chlor-alkali plant contamination of Aussa River sediments induced a large Hg-resistant bacterial community

    Science.gov (United States)

    Baldi, Franco; Marchetto, Davide; Gallo, Michele; Fani, Renato; Maida, Isabel; Covelli, Stefano; Fajon, Vesna; Zizek, Suzana; Hines, Mark; Horvat, Milena

    2012-11-01

    A closed chlor-alkali plant (CAP) discharged Hg for decades into the Aussa River, which flows into Marano Lagoon, resulting in the large-scale pollution of the lagoon. In order to get information on the role of bacteria as mercury detoxifying agents, analyses of anions in the superficial part (0-1 cm) of sediments were conducted at four stations in the Aussa River. In addition, measurements of biopolymeric carbon (BPC) as a sum of the carbon equivalent of proteins (PRT), lipids (LIP), and carbohydrates (CHO) were performed to correlate with bacterial biomass such as the number of aerobic heterotrophic cultivable bacteria and their percentage of Hg-resistant bacteria. All these parameters were used to assess the bioavailable Hg fraction in sediments and the potential detoxification activity of bacteria. In addition, fifteen isolates were characterized by a combination of molecular techniques, which permitted their assignment into six different genera. Four out of fifteen were Gram negative with two strains of Stenotrophomonas maltophilia, one Enterobacter sp., and one strain of Brevibacterium frigoritolerans. The remaining strains (11) were Gram positive belonging to the genera Bacillus and Staphylococcus. We found merA genes in only a few isolates. Mercury volatilization from added HgCl2 and the presence of plasmids with the merA gene were also used to confirm Hg reductase activity. We found the highest number of aerobic heterotrophic Hg-resistant bacteria (one order magnitude higher) and the highest number of Hg-resistant species (11 species out of 15) at the confluence of the River Aussa and Banduzzi's channel, which transport Hg from the CAP, suggesting that Hg is strongly detoxified [reduced to Hg(0)] at this location.

  20. Fermentation and recovery of glutamic acid from palm waste hydrolysate by Ion-exchange resin column.

    Science.gov (United States)

    Das, K; Anis, M; Azemi, B M; Ismail, N

    1995-12-05

    Glutamic acid produced from palm waste hydrolysate by fermentation with Brevibacterium lactofermentum ATCC 13869 is produced with a remarkably high yield compared with that produced from pure glucose as a carbon source. The produce yield is 70 g/L with glucose, wherease, when palm waste hydrolysate is the fermentation medium in the same bioreactor under same conditions, it is 88 g/L. The higher yield may be attributed to the fact that this organism has the ability to convert sugars other than only glucose present in the hydrolysate. Bioreactor conditions most conducive for maximum production are pH 7.5, temperature of 30 degrees rmentation period of 48 h, inoculum size 6%, substrate concentration of 10 g per 100 mL, yeast extract 0.5 g per 100 mL as a suitable N source, and biotin at a concentration of 10 pg/L. Palm waste hydrolysate used in this study was prepared by enzymic saccharification of treated palm press fiber under conditions that yielded a maximum of 30 g/L total reducing sugars. Glutamic acid from fermentation broth was recovered by using a chromatographic column (5cm x 60 cm) packed with a strong ion-exchange resin. The filtered broth containing glutamic acid and other inorganic ions was fed to the fully charged column. The broth was continuously recycled at a flow rate of 50 mL/min (retention time of 55 min) until glutamic acid was fully adsorbed on the column leaving other ions in the effluent. Recovery was done by eluting with urea and sodium hydroxide for total displacement of glutamic acid from the resin. The eluent containing 88 g/L of glutamic acid was concentrated by evaporation to obtain solid crystals of the product. (c) 1995 John Wiley & Sons, Inc.

  1. Dynamics of bacterial communities during the ripening process of different Croatian cheese types derived from raw ewe's milk cheeses.

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    Mirna Mrkonjić Fuka

    Full Text Available Microbial communities play an important role in cheese ripening and determine the flavor and taste of different cheese types to a large extent. However, under adverse conditions human pathogens may colonize cheese samples during ripening and may thus cause severe outbreaks of diarrhoea and other diseases. Therefore in the present study we investigated the bacterial community structure of three raw ewe's milk cheese types, which are produced without the application of starter cultures during ripening from two production sites based on fingerprinting in combination with next generation sequencing of 16S rRNA gene amplicons. Overall a surprisingly high diversity was found in the analyzed samples and overall up to 213 OTU97 could be assigned. 20 of the major OTUs were present in all samples and include mostly lactic acid bacteria (LAB, mainly Lactococcus, and Enterococcus species. Abundance and diversity of these genera differed to a large extent between the 3 investigated cheese types and in response to the ripening process. Also a large number of non LAB genera could be identified based on phylogenetic alignments including mainly Enterobacteriaceae and Staphylococcacae. Some species belonging to these two families could be clearly assigned to species which are known as potential human pathogens like Staphylococcus saprophyticus or Salmonella spp. However, during cheese ripening their abundance was reduced. The bacterial genera, namely Lactobacillus, Streptococcus, Leuconostoc, Bifidobacterium, Brevibacterium, Corynebacterium, Clostridium, Staphylococcus, Thermoanerobacterium, E. coli, Hafnia, Pseudomonas, Janthinobacterium, Petrotoga, Kosmotoga, Megasphaera, Macrococcus, Mannheimia, Aerococcus, Vagococcus, Weissella and Pediococcus were identified at a relative low level and only in selected samples. Overall the microbial composition of the used milk and the management of the production units determined the bacterial community composition for all

  2. Production of recombinant cholesterol oxidase containing covalently bound FAD in Escherichia coli

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    Molla Gianluca

    2010-04-01

    Full Text Available Abstract Background Cholesterol oxidase is an alcohol dehydrogenase/oxidase flavoprotein that catalyzes the dehydrogenation of C(3-OH of cholesterol. It has two major biotechnological applications, i.e. in the determination of serum (and food cholesterol levels and as biocatalyst providing valuable intermediates for industrial steroid drug production. Cholesterol oxidases of type I are those containing the FAD cofactor tightly but not covalently bound to the protein moiety, whereas type II members contain covalently bound FAD. This is the first report on the over-expression in Escherichia coli of type II cholesterol oxidase from Brevibacterium sterolicum (BCO. Results Design of the plasmid construct encoding the mature BCO, optimization of medium composition and identification of the best cultivation/induction conditions for growing and expressing the active protein in recombinant E. coli cells, concurred to achieve a valuable improvement: BCO volumetric productivity was increased from ~500 up to ~25000 U/L and its crude extract specific activity from 0.5 up to 7.0 U/mg protein. Interestingly, under optimal expression conditions, nearly 55% of the soluble recombinant BCO is produced as covalently FAD bound form, whereas the protein containing non-covalently bound FAD is preferentially accumulated in insoluble inclusion bodies. Conclusions Comparison of our results with those published on non-covalent (type I COs expressed in recombinant form (either in E. coli or Streptomyces spp., shows that the fully active type II BCO can be produced in E. coli at valuable expression levels. The improved over-production of the FAD-bound cholesterol oxidase will support its development as a novel biotool to be exploited in biotechnological applications.

  3. 4-nitrocatechol as a probe of a Mn(II)-dependent extradiol-cleaving catechol dioxygenase (MndD): comparison with relevant Fe(II) and Mn(II) model complexes.

    Science.gov (United States)

    Reynolds, Mark F; Costas, Miquel; Ito, Masami; Jo, Du-Hwan; Tipton, A Alex; Whiting, Adam K; Que, Lawrence

    2003-02-01

    Mn(II)-dependent 3,4-dihydroxyphenylacetate 2,3-dioxygenase (MndD) is an extradiol-cleaving catechol dioxygenase from Arthrobacter globiformis that has 82% sequence identity to and cleaves the same substrate (3,4-dihydroxyphenylacetic acid) as Fe(II)-dependent 3,4-dihydroxyphenylacetate 2,3-dioxygenase (HPCD) from Brevibacterium fuscum. We have observed that MndD binds the chromophoric 4-nitrocatechol (4-NCH(2)) substrate as a dianion and cleaves it extremely slowly, in contrast to the Fe(II)-dependent enzymes which bind 4-NCH(2) mostly as a monoanion and cleave 4-NCH(2) 4-5 orders of magnitude faster. These results suggest that the monoanionic binding state of 4-NC is essential for extradiol cleavage. In order to address the differences in 4-NCH(2) binding to these enzymes, we synthesized and characterized the first mononuclear monoanionic and dianionic Mn(II)-(4-NC) model complexes as well as their Fe(II)-(4-NC) analogs. The structures of [(6-Me(2)-bpmcn)Fe(II)(4-NCH)](+), [(6-Me(3)-TPA)Mn(II)(DBCH)](+), and [(6-Me(2)-bpmcn)Mn(II)(4-NCH)](+) reveal that the monoanionic catecholate is bound in an asymmetric fashion (Delta r(metal-O(catecholate))=0.25-0.35 A), as found in the crystal structures of the E(.)S complexes of extradiol-cleaving catechol dioxygenases. Acid-base titrations of [(L)M(II)(4-NCH)](+) complexes in aprotic solvents show that the p K(a) of the second catecholate proton of 4-NCH bound to the metal center is half a p K(a) unit higher for the Mn(II) complexes than for the Fe(II) complexes. These results are in line with the Lewis acidities of the two divalent metal ions but are the opposite of the trend observed for 4-NCH(2) binding to the Mn(II)- and Fe(II)-catechol dioxygenases. These results suggest that the MndD active site decreases the second p K(a) of the bound 4-NCH(2) relative to the HPCD active site.

  4. 河西灌区马铃薯茎基腐病的发生规律与防治技术研究%Occurrence and control of potato crown rot in irrigated areas of Hexi Corridor

    Institute of Scientific and Technical Information of China (English)

    雷玉明; 张建朝; 费永祥; 邢会琴; 张建文

    2011-01-01

    本文首次报道马铃薯茎基腐病在田间表现为立枯型、萎蔫型、根腐型、黄化型4种症状类型,一般在苗期至现蕾期、开花期至结薯期为发病高峰期;明确了河西灌区种植的大多数品种对茎基腐病无明显抗性;发病程度与多种因素有关,灰钙土发病较重,其次为壤土,沙土发病较轻;土壤pH与含水量较高发病重;植株密度较高发病重;连作年限越长发病越重;与油菜、茄科蔬菜连作发病较重;高温有利于该病发生;经药剂种薯、土壤、灌根处理表明:以代森锰锌、菌核净和敌磺钠种薯和土壤处理,代森锰锌、井·1亿活枯草芽孢菌、菌核净灌根处理,防效达50.3%~65.9%.%The symptoms of potato crown rot were recorded for the first time, i.e.damping-off, wilt, root rot and yellowing.The disease severely occurred during seedling, budding, flowering and fruiting stages.No significant resistance to crown rot had been observed in most cultivars.The effect of soil texture on potato crown rot was that the disease index was highest in sierozem, lower in clay loam and lowest in sandy soils.The disease occurrence was more serious in alkaline soils with high water content than in weak acid or neutral soils with low water content.High density caused serious disease.The longer the consecutive cropping lasted, the more seriously the disease occurred.Rape-potato and solanaceae-potato cropping also caused more serious disease.High temperature and moisture were good for potato crown rot occurrence.Control tests indicated that the efficacy of mancozeb,dimetachlone and fenaminosulf with seed treatment and soil treatment, and mancozeb, dimetachlone and brevibacterium with root-irrigating treatment were between 50.3% and 65.9%.

  5. Mobilization of manganese by basalt associated Mn(II)-oxidizing bacteria from the Indian Ridge System.

    Science.gov (United States)

    Sujith, P P; Mourya, B S; Krishnamurthi, S; Meena, R M; Loka Bharathi, P A

    2014-01-01

    The Indian Ridge System basalt bearing Mn-oxide coatings had todorokite as the major and birnesite as the minor mineral. We posit that microorganisms associated with these basalts participate in the oxidation of Mn and contribute to mineral deposition. We also hypothesized that, the Mn-oxidizing microbes may respond reversibly to pulses of fresh organic carbon introduced into the water column by mobilizing the Mn in Mn-oxides. To test these two hypotheses, we enumerated the number of Mn-oxidizers and -reducers and carried out studies on the mobilization of Mn by microbial communities associated with basalt. In medium containing 100 μM Mn(2+), 10(3) colony forming units (CFU) were recovered with undetectable number of reducers on Mn-oxide amended medium, suggesting that the community was more oxidative. Experiments were then conducted with basalt fragments at 4±2 °C in the presence 'G(+)' and absence 'G(-)' of glucose (0.1%). Controls included set-ups, some of which were poisoned with 15 mM azide and the others of which were heat-killed. The mobilization of Mn in the presence of glucose was 1.76 μg g(-1) d(-1) and in the absence, it was 0.17 μg g(-1) d(-1) after 150 d. Mn mobilization with and without added glucose was 13 and 4 times greater than the corresponding azide treated controls. However, rates in 'G(+)' were 16 times and 'G(-)' 24 times more than the respective heat killed controls. The corresponding total counts in the presence of added glucose increased from 1.63×10(6) to 6.71×10(7) cells g(-1) and from 1.41×10(7) to 3.52×10(7) cells g(-1) in its absence. Thus, the addition of glucose as a proxy for organic carbon changed the community's response from Mn(II)-oxidizing to Mn(IV)-reducing activity. The results confirm the participation of Mn oxidizing bacteria in the mobilization of Mn. Identification of culturable bacteria by 16S rRNA gene analysis showed taxonomic affiliations to Bacillus, Exiguobacterium, Staphylococcus, Brevibacterium and

  6. Microbiota characterization of a Belgian protected designation of origin cheese, Herve cheese, using metagenomic analysis.

    Science.gov (United States)

    Delcenserie, V; Taminiau, B; Delhalle, L; Nezer, C; Doyen, P; Crevecoeur, S; Roussey, D; Korsak, N; Daube, G

    2014-10-01

    Herve cheese is a Belgian soft cheese with a washed rind, and is made from raw or pasteurized milk. The specific microbiota of this cheese has never previously been fully explored and the use of raw or pasteurized milk in addition to starters is assumed to affect the microbiota of the rind and the heart. The aim of the study was to analyze the bacterial microbiota of Herve cheese using classical microbiology and a metagenomic approach based on 16S ribosomal DNA pyrosequencing. Using classical microbiology, the total counts of bacteria were comparable for the 11 samples of tested raw and pasteurized milk cheeses, reaching almost 8 log cfu/g. Using the metagenomic approach, 207 different phylotypes were identified. The rind of both the raw and pasteurized milk cheeses was found to be highly diversified. However, 96.3 and 97.9% of the total microbiota of the raw milk and pasteurized cheese rind, respectively, were composed of species present in both types of cheese, such as Corynebacterium casei, Psychrobacter spp., Lactococcus lactis ssp. cremoris, Staphylococcus equorum, Vagococcus salmoninarum, and other species present at levels below 5%. Brevibacterium linens were present at low levels (0.5 and 1.6%, respectively) on the rind of both the raw and the pasteurized milk cheeses, even though this bacterium had been inoculated during the manufacturing process. Interestingly, Psychroflexus casei, also described as giving a red smear to Raclette-type cheese, was identified in small proportions in the composition of the rind of both the raw and pasteurized milk cheeses (0.17 and 0.5%, respectively). In the heart of the cheeses, the common species of bacteria reached more than 99%. The main species identified were Lactococcus lactis ssp. cremoris, Psychrobacter spp., and Staphylococcus equorum ssp. equorum. Interestingly, 93 phylotypes were present only in the raw milk cheeses and 29 only in the pasteurized milk cheeses, showing the high diversity of the microbiota

  7. Studying of Biosynthetic Pathways of 2H-labeled Purine Ribonucleoside Inosine in a Chemoheterotrophic Bacterium Bacillus subtilis B-3157 by FAB Mass-Spectrometry

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    Oleg Mosin

    2015-09-01

    Full Text Available This paper deals with studying biosynthetic pathways of 2H-labeled purine ribonucleoside inosine excreted into liquid microbial culture (LC by Gram-positive chemoheterotrophic bacterium Bacillus subtilis B-3157 while growing of this bacterium on heavy water (HW medium with 2% (v/v hydrolysate of deuterated biomass of the methylotrophic bacterium Brevibacterium methylicum B-5662 as a source of 2H-labeled growth substrates. Isolation of 2H-labeled inosine from LC was performed by adsorption/desorption on activated carbon with following extraction by 0,3 M ammonium–formate buffer (pH = 8,9, crystallization in 80% (v/v EtOH, and ion exchange chromatography (IEC on a column with AG50WX 4 cation exchange resin equilibrated with 0,3 M ammonium–formate buffer and 0,045 M NH4Cl. The investigation of deuterium incorporation into the inosine molecule by FAB method demonstrated incorporation of 5 deuterium atoms into the molecule (the total level of deuterium enrichment – 65,5 atom% 2H with 3 deuterium atoms being included into the ribose and 2 deuterium atoms – into the hypoxanthine residue of the molecule. Three non-exchangeable deuterium atoms were incorporated into the ribose residue owing to the preservation in this bacterium the minor pathways of de novo glucose biosynthesis in 2H2O-medium. These non-exchangeable deuterium atoms in the ribose residue were originated from HMP shunt reactions, while two other deuterium atoms at C2, C8-positions in the hypoxanthine residue were synthesized from [2H]amino acids, primarily glutamine and glycine, that originated from deuterated hydrolysate. A glycoside proton at -N9-glycosidic bond could be replaced with deuterium via the reaction of СО2 elimination at the stage of ribulose-5-monophosphate formation from 3-keto-6-phosphogluconic acid with subsequent proton (deuteron attachment at the С1-position of ribulose-5-monophosphate. Two other protons at C2(C3 and C4 positions in ribose residue could be

  8. Population dynamics of two antilisterial cheese surface consortia revealed by temporal temperature gradient gel electrophoresis

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    Hasler Madlen

    2010-03-01

    Full Text Available Abstract Background Surface contamination of smear cheese by Listeria spp. is of major concern for the industry. Complex smear ecosystems have been shown to harbor antilisterial potential but the microorganisms and mechanisms involved in the inhibition mostly remain unclear, and are likely related to complex interactions than to production of single antimicrobial compounds. Bacterial biodiversity and population dynamics of complex smear ecosystems exhibiting antilisterial properties in situ were investigated by Temporal temperature gradient gel electrophoresis (TTGE, a culture independent technique, for two microbial consortia isolated from commercial Raclette type cheeses inoculated with defined commercial ripening cultures (F or produced with an old-young smearing process (M. Results TTGE revealed nine bacterial species common to both F and M consortia, but consortium F exhibited a higher diversity than consortium M, with thirteen and ten species, respectively. Population dynamics were studied after application of the consortia on fresh-produced Raclette cheeses. TTGE analyses revealed a similar sequential development of the nine species common to both consortia. Beside common cheese surface bacteria (Staphylococcus equorum, Corynebacterium spp., Brevibacterium linens, Microbacterium gubbeenense, Agrococcus casei, the two consortia contained marine lactic acid bacteria (Alkalibacterium kapii, Marinilactibacillus psychrotolerans that developed early in ripening (day 14 to 20, shortly after the growth of staphylococci (day 7. A decrease of Listeria counts was observed on cheese surface inoculated at day 7 with 0.1-1 × 102 CFU cm-2, when cheeses were smeared with consortium F or M. Listeria counts went below the detection limit of the method between day 14 and 28 and no subsequent regrowth was detected over 60 to 80 ripening days. In contrast, Listeria grew to high counts (105 CFU cm-2 on cheeses smeared with a defined surface culture

  9. Investigation of the Activity of the Microorganisms in a Reblochon-Style Cheese by Metatranscriptomic Analysis.

    Science.gov (United States)

    Monnet, Christophe; Dugat-Bony, Eric; Swennen, Dominique; Beckerich, Jean-Marie; Irlinger, Françoise; Fraud, Sébastien; Bonnarme, Pascal

    2016-01-01

    The microbial communities in cheeses are composed of varying bacteria, yeasts, and molds, which contribute to the development of their typical sensory properties. In situ studies are needed to better understand their growth and activity during cheese ripening. Our objective was to investigate the activity of the microorganisms used for manufacturing a surface-ripened cheese by means of metatranscriptomic analysis. The cheeses were produced using two lactic acid bacteria (Streptococcus thermophilus and Lactobacillus delbrueckii ssp. bulgaricus), one ripening bacterium (Brevibacterium aurantiacum), and two yeasts (Debaryomyces hansenii and Geotrichum candidum). RNA was extracted from the cheese rinds and, after depletion of most ribosomal RNA, sequencing was performed using a short-read sequencing technology that generated ~75 million reads per sample. Except for B. aurantiacum, which failed to grow in the cheeses, a large number of CDS reads were generated for the inoculated species, making it possible to investigate their individual transcriptome over time. From day 5 to 35, G. candidum accounted for the largest proportion of CDS reads, suggesting that this species was the most active. Only minor changes occurred in the transcriptomes of the lactic acid bacteria. For the two yeasts, we compared the expression of genes involved in the catabolism of lactose, galactose, lactate, amino acids, and free fatty acids. During ripening, genes involved in ammonia assimilation and galactose catabolism were down-regulated in the two species. Genes involved in amino acid catabolism were up-regulated in G. candidum from day 14 to day 35, whereas in D. hansenii, they were up-regulated mainly at day 35, suggesting that this species catabolized the cheese amino acids later. In addition, after 35 days of ripening, there was a down-regulation of genes involved in the electron transport chain, suggesting a lower cellular activity. The present study has exemplified how

  10. Assessment of the Microbial Constituents of the Home Environment of Individuals with Cystic Fibrosis (CF and Their Association with Lower Airways Infections.

    Directory of Open Access Journals (Sweden)

    Alya Heirali

    Full Text Available Cystic fibrosis (CF airways are colonized by a polymicrobial community of organisms, termed the CF microbiota. We sought to define the microbial constituents of the home environment of individuals with CF and determine if it may serve as a latent reservoir for infection.Six patients with newly identified CF pathogens were included. An investigator collected repeat sputum and multiple environmental samples from their homes. Bacteria were cultured under both aerobic and anaerobic conditions. Morphologically distinct colonies were selected, purified and identified to the genus and species level through 16S rRNA gene sequencing. When concordant organisms were identified in sputum and environment, pulsed-field gel electrophoresis (PFGE was performed to determine relatedness. Culture-independent bacterial profiling of each sample was carried out by Illumina sequencing of the V3 region of the 16s RNA gene.New respiratory pathogens prompting investigation included: Mycobacterium abscessus(2, Stenotrophomonas maltophilia(3, Pseudomonas aeruginosa(3, Pseudomonas fluorescens(1, Nocardia spp.(1, and Achromobacter xylosoxidans(1. A median 25 organisms/patient were cultured from sputum. A median 125 organisms/home were cultured from environmental sites. Several organisms commonly found in the CF lung microbiome were identified within the home environments of these patients. Concordant species included members of the following genera: Brevibacterium(1, Microbacterium(1, Staphylococcus(3, Stenotrophomonas(2, Streptococcus(2, Sphingomonas(1, and Pseudomonas(4. PFGE confirmed related strains (one episode each of Sphinogomonas and P. aeruginosa from the environment and airways were identified in two patients. Culture-independent assessment confirmed that many organisms were not identified using culture-dependent techniques.Members of the CF microbiota can be found as constituents of the home environment in individuals with CF. While the majority of isolates from

  11. Microbial biodiversity in cheese consortia and comparative Listeria growth on surfaces of uncooked pressed cheeses.

    Science.gov (United States)

    Callon, Cécile; Retureau, Emilie; Didienne, Robert; Montel, Marie-Christine

    2014-03-17

    psychrotolerans and Gram positive catalase positive bacteria represented by Staphylococcus vitulinus, Brevibacterium linens, Microbacterium gubbeenense and Brachybacterium tyrofermentans. The results show that the species composition of consortium is more important than the number of species. It is likely that inhibition mechanisms differ from one consortium to another; investigating gene expression will be an effective way to elucidate microbial interactions in cheese.

  12. Study on the Phylogeny and Growth Promoting Effect of Endophytes Isolated from Legume Root Nodules in Hoh Xil%可可西里豆科植物根瘤内生细菌系统发育及促生特性研究

    Institute of Scientific and Technical Information of China (English)

    王金平; 齐雅琳; 韩素贞

    2016-01-01

    Objective] The aim was to study the phylogeny,antimicrobial activity and secreting IAA capacity of endophytes isolated from legume root nodules in Hoh Xil.[Method] The endophyte strains isolated from the nodules of Oxytropis falcate Bunge in Hoh Xil were used to do the 16s sequences analysis,antimicrobial test and IAA detection.[Result] The result of 16s rDNA sequence analysis showed that 12 of 17 test strains be-long to Bacillus.CNU097903 and Brevibacterium halotolerans,CNU097916 and Agrobacterium tumefaciens were at the same branch respectively , which similarity were as high as 99.9%and 99.8%.CNU097914 and CNU097915 were in a separate branch and their system development status remained to be further confirmed.The antimicrobial experiment result showed that 10 strains had the different degrees of resistance to Xan-thomonas campestris,Staphylococcus aureus,Botrytis cinerea,and Pythium aphanidermatum.CNU097906 had the highest resistant spectrum which could resist to all 4 indicator bacteria.CNU097902 and CNU097908 had the strongest resistance to Botrytis cinerea,Xanthomonas campestris re-spectively and the bacteriostatic circle of 38 mm in diameter.CNU097901 had the strongest resistance for Staphylococcus aureus,and the bacterio-static circle of 41 mm in diameter.The Salkowski colorimetric method showed that all the 10 selected strains had the ability to secrete IAA.[Con-clusion] The study lays a foundation for further research on prevention mechanism and ways of endophytic bacteria ,provides theoretical basis for research of endophytic bacteria in Hoh Xil and rational decelopment .%[目的]研究可可西里豆科植物根瘤内生细菌系统发育、抗菌特性和分泌IAA能力。[方法]对分离自可可西里的豆科植物Oxyt-ropis falcate Bunge的根瘤内生细菌进行了16S rDNA全序列分析、抗菌试验以及IAA分泌能力检测。[结果]16S rDNA全序列分析结果表明,17株供试菌有12株属于芽孢杆菌属( Bacillus);有1

  13. 湖南衡阳铀尾矿库中微生物分布调查及优势菌鉴定%Investigation of the microbial distribution and identification of single isolates of uranium tailings impoundment in Hunan

    Institute of Scientific and Technical Information of China (English)

    朱捷; 何微; 陈晓明; 刘梅; 张娥; 柳芳; 陈浩

    2013-01-01

    identified as Bacillus, Ub for Enterobacter, Uc for Arthrobacter, Ud for Brevibacterium, Uh for Paenibacillus, and Uj for Kocuria strains, though the results of similarity proved by using Biolog method seem to be lower than that probed by using 16S rDNA method.%为了考察铀尾矿库中微生物的分布情况,筛选优势菌株,通过稀释涂布法对湖南衡阳铀尾矿库3个不同坝体(N坝、E坝、S坝)的矿渣样品进行研究,利用16S rDNA及Biolog系统鉴定微生物.结果表明,铀尾矿中微生物的数量和种类均明显少于普通土壤,不同菌群数量从多到少为细菌、放线菌、霉菌.不同坝体微生物总量从多到少为S坝、N坝、E坝.N坝细菌的数量较多,占微生物总量的99%;S坝放线菌及霉菌数量最多.E坝和S坝中微生物的数量和种类较为相似.E坝放线菌数量随矿渣深度增加而增加,霉菌数量则相反;S坝中细菌数量随矿渣深度递增.分离出12株优势菌株,经16S rDNA比对,可分为芽孢杆菌属(Bacillus)、肠杆菌属(Enterobacter)、节杆菌属(Arthrobacter)、短杆菌属(Brevibacterium)、类芽孢杆菌属(Paenibacillus)及库克菌属(Kocuria rosea);与Biolog鉴定结果相似,但Biolog结果相似度较低.

  14. Effect of Trichoderma harzianum T4 on Bacterial Community in Watermelon (Citrullus lanatus) Rhizosphere Soil%生防菌哈茨木霉Trichoderma harzianum T4对西瓜根围土壤细菌群落的影响

    Institute of Scientific and Technical Information of China (English)

    夏飞; 张于; 旭热; 王伟

    2013-01-01

      采用平板培养、末端限制性片段长度多态性(terminal restriction fragment length polymorphism, T-RFLP)以及变性梯度凝胶电泳(denatured gradient gel electrophoresis, DGGE)的方法相结合探讨生防菌哈茨木霉 Trichoderma harzianum T4对大棚西瓜根围土壤细菌群落及氨氧化细菌群落的影响,为其在田间应用的生态安全性的评估提供支撑。末端限制性片段长度多态性以及变性梯度凝胶电泳的结果均表明哈茨木霉 T4施入田间约四周内对根围土壤细菌群落产生明显的影响,随后这种扰动现象逐渐减小。对 DGGE中受影响条带的测序结果表明,生防菌 T4促进了假单胞菌 Pseudomonas,芽孢杆菌 Bacillus,苍白杆菌Ochrobactrum 以及中慢生根瘤菌 Mesorhizobium 等细菌类群的生长,对短杆菌 Brevibacterium,克雷白氏肺炎杆菌 Klebsiella pneumoniae,根瘤菌 Rhizobium sp 等表现出抑制作用。生防菌 T4对根围土壤中氨氧化细菌群落并没有产生明显的影响。可见,生防菌木霉 T4引入初期对根围土壤中细菌群落产生明显的扰动,但这种干扰是短暂的,并没有对根围土壤细菌群落形成持续的影响。%The effects of biocontrol strain Trichoderma harzianum T4 on bacterial and ammonia-oxidizing bacteria (AOB) communities in watermelon (Citrullus lanatus) rhizosphere soil were studied using plate colony calculation, T-RFLP and DGGE method, in order to provide a theoretical basis and technique for assessing the microbial ecology risk of biocontrol agents application. Both T-RFLP and DGGE method demonstrated that T. harzianum T4 had short-term influence on rhizosphere soil bacterial communities which lasted about four weeks. Biocontrol strain T. harzianum T4 increased population of some bacteria, such as Pseudomonas, Bacillus, Ochrobactrum and Mesorhizobium. Meanwhile population of other bacteria such as Brevibacterium and Klebsiella pneumoniae were

  15. Analysis of infection prevention and continuous improvement of artificial joint replacement surgery%人工关节置换术感染预防与持续改进分析

    Institute of Scientific and Technical Information of China (English)

    于传亭; 厉吉霞; 徐锦; 杨春玲; 孙东绣

    2014-01-01

    Objective To analyze the causes of reducing postoperative infection after joint replacement and to observe the prophylactic mangement measures.Methods Totally 309 patients with total joint replacements of Yantaishan hospital of Yantai city were selected and divided into improving before group (94 cases) and improving group (215 cases).The speciments for bacterial culture were taken from the hands of the operation surgeon,the scrub nurse and the air flow in the operation room for all cases.The growth of bacteria after improvement was observed.Results There were significant differences on bacteria growth rate of air aulture in improving group compared with improve before group [59.5 % (128/215) vs 73.4% (69/94)] (P < 0.05).There were significant differences on bacteria growth rate of hand of surgeon and nurse in improving group compared with improving before group [1.9% (4/215) vs 6.4% (6/94)] (P < 0.05).There were Micrococcus,Corynebacterium,Staphylococcus haemolyticus,Neisseria,Brevibacterium bacteria,Serratia marcescens,Staphylococcus epidermidis and Baumanii from bacterial culture of hands of the operation surgeon,scrub nurse and the air flow.Conclusion Improvement of the management in the operation room and checking the laminar air flow device regularly are important for the infection prevention after total joint replacement.%目的 预防性管理措施改进对人工关节转换术术后感染的影响.方法 收集山东省烟台市烟台山医院收治的309例施行人工关节置换术的患者,按改进前后时间将患者分为改进前组(94例)和改进后组(215例).对2组患者术中空气、主刀人员的手、手术护士的手进行细菌采集,观察改进前与改进后的细菌生长情况.结果 改进后组空气培养有细菌生长率与改进前组比较,差异有统计学意义[59.5%(128/215)比73.4% (69/94)](P<0.05).空气培养中的细菌有微球菌、棒状杆菌、溶血葡萄球菌、奈瑟菌、柘草芽孢

  16. Preparation and Immunomodulatory Properties of Modified Peptidoglycan Fragments

    Directory of Open Access Journals (Sweden)

    Tomić, S.

    2013-01-01

    Full Text Available Immunostimulators, known also as adjuvants, are added to vaccines to accelerate, extend or amplify the specific immune reaction to a specific antigen. One well known class of immuno- modulating compounds is based on muramylpeptides which are fragments of peptidoglycans, natural polymers that build up the cell wall of bacteria. Muramyldipeptide, N-acetyl- muramyl-L-alanyl-D-isoglutamine (MDP, Fig. 1 is the smallest structural unit of the peptidoglycan monomer (PGM, Fig. 2 which shows immunostimulating activity. PGM isolated from Brevibacterium divaricatum, acts in itself as an effective adjuvant, and several derivatives were prepared to study the possible influence of different substituents on the immunomodulatory activity. Thus, lipophilic derivativestert-butyloxycarbonyl-L-tyrosyl-PGM and (adamant- 1-ylacetyl-PGM (Fig. 3 were prepared and their activities studied. They were also shown to be good substrates for N-acetylmuramyl-L-alanine amidase from human serum (Scheme 1 which specifically hydrolyzes the lactylamide bond. MDP which is an integral part of PGM and proven to be an effective adjuvant was further synthetically modified and obtained derivatives tested as possible immunomodulators. Romutide (MDP-Lys(L18, approved by Food and Drug Administration (FDA, and mifamurtide (L-MTP-PE, approved by European Medicines Agency (EMA, highlight among many other MDP derivatives (Fig. 4. Since N-acetylglucosamine in the structure of MDP is not essential for the immunostimulating effect, desmuramyldipeptides (Fig. 5 with different acyl groups at N-terminus of L-Ala-D-isoGln dipeptide were prepared. In ada mantyl desmuramyldipeptides such as adamantylamide dipeptide (Fig 6, adamantyl tripeptides (Fig. 7 and desmuramylpeptides with (adamant-1-ylcarboxyamido group (Fig. 8, lipophilic adamantane moiety is bound to the dipeptide part. Binding of some specific sugars to immune active substances may help their targeted delivery. An example is mannose which

  17. Characterisation of prototype Nurmi cultures using culture-based microbiological techniques and PCR-DGGE.

    Science.gov (United States)

    Waters, Sinéad M; Murphy, Richard A; Power, Ronan F G

    2006-08-01

    Undefined Nurmi-type cultures (NTCs) have been used successfully to prevent salmonella colonisation in poultry for decades. Such cultures are derived from the caecal contents of specific-pathogen-free birds and are administered via drinking water or spray application onto eggs in the hatchery. These cultures consist of many non-culturable and obligately anaerobic bacteria. Due to their undefined nature it is difficult to obtain approval from regulatory agencies to use these preparations as direct fed microbials for poultry. In this study, 10 batches of prototype NTCs were produced using an identical protocol over a period of 2 years. Traditional microbiological techniques and a molecular culture-independent methodology, polymerase chain reaction combined with denaturing gradient gel electrophoresis (PCR-DGGE), were applied to characterise these cultures and also to examine if the constituents of the NTCs were identical. Culture-dependent analysis of these cultures included plating on a variety of selective and semi-selective agars, examination of colony morphology, Gram-staining and a series of biochemical tests (API, BioMerieux, France). Two sets of PCR-DGGE studies were performed. These involved the amplification of universal and subsequently lactic acid bacteria (LAB)-specific hypervariable regions of a 16S rRNA gene by PCR. Resultant amplicons were subjected to DGGE. Sequence analysis was performed on subsequent bands present in resultant DGGE profiles using the Basic Local Alignment Search Tool (BLAST). Microbiological culturing techniques tended to isolate common probiotic bacterial species from the genera Lactobacillus, Lactococcus, Bifidobacterium, Enterococcus, Clostridium, Escherichia, Pediococcus and Enterobacterium as well as members of the genera, Actinomyces, Bacteroides, Propionibacterium, Capnocytophaga, Proteus, and Klebsiella. Bacteroides, Enterococcus, Escherichia, Brevibacterium, Klebsiella, Lactobacillus, Clostridium, Bacillus, Eubacterium

  18. 臭氧-接种生物滤池组合工艺去除饮用水中典型致嗅物质%Ozonation-Inoculated Biofiltration for Removal of the Typical Taste and Odor Compounds in Drinking Water

    Institute of Scientific and Technical Information of China (English)

    袁蓉芳; 周北海; 施春红; 顾军农; 李玉仙

    2013-01-01

    通过在生物滤池表面接种MIB(2-甲基异茨醇)及geosmin(土臭素)降解菌,增强生物滤池的作用,并探讨臭氧-生物滤池组合工艺对MIB和geosmin的处理效果.结果表明:单独接种生物滤池可使ρ(MIB)和ρ(geosmin)从初始的500 ng/L分别降至125和112 ng/L,MIB和geosmin的去除效果先随EBCT(空床停留时间)的延长而显著增加,但当EBCT大于20 min后无明显变化;随着滤料深度的增加,滤池生物量逐渐降低,对污染物的去除率增加缓慢.在接种生物滤池前增加臭氧单元,当EBCT为20min、臭氧投加量为2 mg/L时,臭氧-接种生物滤池组合工艺可去除84%的MIB和94%的geosmin,其中接种生物滤池单元中生物量随滤池深度的增加呈先增后减的趋势,滤料深度为100~200 mm时,单位高度滤料的去除率最高.采用臭氧-接种生物滤池组合工艺可有效去除水中的MIB和geosmin.%2-methylisoborneol (MIB) and geosmin are two of the most common taste and odor compounds which can not be readily removed by conventional drinking water treatment processes.The objective of this study was to enhance the biofiltration of MIB and geosmin by inoculating the sand filter with MIB and geosmin degraders,and to examine the removal efficiencies of MIB and geosmin using inoculated filter and non-inoculated filter in the presence and absence of ozonation.The degraders were Micrococcus sp.,Flavobacterium sp.,Brevibacterium sp.and Pseudomonas sp.as MIB degraders,and Chryseobacterium sp.,Sinorhizobium sp.,and Stenotrophomonas sp.as geosmin degraders.These bacteria were isolated from granular activated carbon in a commercial water plant.For the filter inoculated with a consortium of MIB and geosmin biodegraders,MIB and geosmin contents were decreased to 125 and 112 ng/L from 500 ng/L,respectively.Initially,removal efficiencies of MIB and geosmin rapidly increased with the extension of empty bed contact time (EBCT),and resulted in no obvious change when EBCT

  19. Isolation and selection of P-dissolving microbes%解磷微生物的分离与筛选

    Institute of Scientific and Technical Information of China (English)

    钟传青; 曹广祥; 黄为一

    2014-01-01

    Phosphorus is the main component of organic compounds in plant and necessary for the biological nitrogen fixation.Most of the phosphorus is insoluble in soil,which cannot be absorbed by plants directly.P-dissolving microbes can promote the transformation of insoluble phosphorus to available phosphorus in soil.The study was centered on the current situation of effective phosphorus deficiency in cultivated land.Diversity of P-dissolving microbes was explored by construction of screening model during the study of initial screening medium and re-screening culture medium.More than 2000 strains of P-dissolving microbes were isolated from different soil samples by solid plate method .Results are shown as follows.P-dissolving microbes are most in vegetable garden soil because of its high content of organic matter.Quantity and kinds of P-dissolving microbes are different in soil from different area.Bacillus P17,Brevibacterium P10,Rhodotorula Y3 are isolated and identified.P-dissolving microbes could be isolated with the screening model by solid plate method,but P-dissolving effect is still needed to be determined combined with liquid screening model.%磷是植物体内有机化合物的主要成分,为生物固氮所必需,土壤中大部分磷以难溶态存在,不能被植物直接吸收利用,解磷微生物可以促进土壤难溶磷向有效磷的转化。基于目前耕地有效磷缺乏的现状,通过对解磷微生物初筛、复筛培养基的研究,探索了解磷微生物的筛选模型以及各地解磷微生物的多样性,对不同类型土壤中分离出的2000多株解磷微生物的溶磷效果进行了研究。结果表明:菜园土中有机质含量高,解磷微生物最多,从全国各地土样及种子表皮中分离出芽孢杆菌P17菌株、短杆菌P10菌株和红酵母Y3菌株等解磷微生物;不同地域、同种地区不同类型土壤中溶解难溶性无机磷和有机磷微生物的种类和数量存在显著差异;

  20. Diversity of culturable bacteria associated with the sea urchin Hemicentrotus pulcherrimus from Naozhou Island%硇洲岛海胆可培养细菌的多样性

    Institute of Scientific and Technical Information of China (English)

    黄苛; 张丽; 刘祝祥; 陈奇辉; 彭清忠; 李文均; 崔晓龙; 陈义光

    2009-01-01

    [Objective] To investigate the diversity of culturable bacteria isolated from the sea urchin Hemicentrotus pulcherrimus collected from a tidal flat of Naozhou Island(20°52'N~20°56'N 110°33'E~110°38'E),Leizhou Bay,South China Sea,China. [Methods] Bacteria were isolated from the sample by using conventional culture-dependent method and then investigated by using phylogenetic analysis based on 16S rRNA gene sequence comparisons.[Results ]We isolated 106 bacterial strains from the sample on media (Difco marine 2216;International Streotomyces Project medium 2;nutrient;sea water and humic acid agars) supplemented with 0~2 mol/L NaCl.On the basis of morphological;physiological and biochemical characteristics;we selected 34 strains to perform a phylogenetic analysis based on 16S rRNA gene sequences.Our results showed that 34 isolates represented 21 species; belonging to 17 genera (Alteromonas, Bacillus, Brachybacterium , Brevibacterium, Halobacillus,Halomonas, Nocardiopsis , Oceanobacillus, Piscibacillus, Planococcus, Pontibadllus, Pseudoalteromonas, Pseudonocardia,Sahnicoccus, Sahnwibrio, Staphylococcus, Vibrio, Virgibacillus) of 10 families (Alteromonadaceae, Bacillaceae,Brevibactenaceae, Dermabacteraceae,Halomonadaceae,Planococcaceae,Pseudoalteromonadaceae,Pseudonocardiaceae;Nocardiopsaceae,Staphylococcaceae,Vibnonaceae)in three phylogenetic groups (Actinobactena,Firmicutes,GammaProteobactena).The most abundant and diverse isolates were within the phylum Firmicutes (58.8%)and the subphylum Gamma-Proteobactena (26.5% ).The phylogenetic distance matrix results suggested that there were obvious genetic divergences between most isolates and their closestly related type strains (16S rRNA gene sequence similarities ranged from 99.6 to 99.9%), and that, out of 34 isolates, at least 5 strains (JSM 076033, JSM 076056, JSM 076093, JSM 078063, JSM 078169) could represent 5 potential new species within 5 characterized genera (Jeotgalicoccus

  1. Marine actinomycetes from Madeira Archipelago preliminary taxonomic studies

    Directory of Open Access Journals (Sweden)

    Ilda Santos Sanches

    2014-06-01

    region and suggesting a more globally distribution of this genus than previously supposed (unplublished results. In this study further 82 strains from Madeira Archipelago (out of 421 were selected for taxonomic identification, taking into account small groups of strains (1-4 evidencing very diverse morphological appearances, as exemplified in Figure 2. Using the same experimental microbiology identification tools, 8 genera were identified. However it was perceived that, the genera Streptomyces, Nocardiopsis and Actinomycetospora were predominant (93%, Figure 3. The phylogenetic trees built for the 82 taxonomically identified strains performed in this study are presented in Figures 4, 5 and 6. To date, having into account the present work and previous studies, our research group have identified from the actinomycetes isolated from Madeira´s ocean sediments, genera Streptomyces, Micromonospora, Salinispora, Nocardiopsis, Verrucosispora, Kocuria, Nonomuraea, Nocardia, Brevibacterium, Mycobacterium, Marinobacter, Actinomadura, Micrococcus, Actinomycetospora, Pseudonocardia, Gordonia and Millisia. From which genera Streptomyces, Micromonospora, Salinispora evidence a major representation. Crude extracts were obtained from all 421 strains and tested for their ability to produce natural products with bioactive properties: (i antimicrobial activity against methicillin-resistant Staphylococcus aureus (MRSA, vancomycin-resistant Enterococcus faecalis (VRE and Candida albicans strains; and (ii cytotoxic activity against the HCT-116 cell line. A screening positive rate of 2.4% for antimicrobial MRSA and VRE assays and 3.2% for cytotoxic HCT-116 assay was obtained (submitted manuscripts. These studies demonstrate that the Macaronesian Atlantic Ocean region is a rich source of marine actinomycete biodiversity with potential industrial applications. Figure 1. Marine actinomycetes sediment sampling locations at Madeira Archipelago. Figure 2. Morphological diversity characteristics of