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Sample records for acetobacter

  1. Cellulose biosynthesis in Acetobacter xylinum

    Energy Technology Data Exchange (ETDEWEB)

    Lin, F.C.

    1988-01-01

    Time-lapse video microscopy has shown periodic reversals during the synthesis of cellulose. In the presence of Congo Red, Acetobacter produces a band of fine fibrils. The direction of cell movement is perpendicular to the longitudinal axis of cell, and the rate of movement was decreased. A linear row of particles, presumably the cellulose synthesizing complexes, was found on the outer membrane by freeze-fracture technique. During the cell cycle, the increase of particles in linear row, the differentiation to four linear rows and the separation of the linear rows have been observed. A digitonin-solubilized cellulose synthase was prepared from A. xylinum, and incubated under conditions known to lead to active in vitro synthesis of 1,4-{beta}-D-glucan polymer. Electron microscopy revealed that clusters of fibrils were assembled within minutes. Individual fibrils are 17 {plus minus} 2 angstroms in diameter. Evidence for the cellulosic composition of newly synthesized fibrils was based on incorporation of tritium from UDP-({sup 3}H) glucose binding of gold-labeled cellobiohydrolase, and an electron diffraction pattern identified as cellulose II polymorph instead of cellulose I.

  2. The mechanism and localization of hexonate metabolism in Acetobacter suboxydans and acetobacter melanogenum

    NARCIS (Netherlands)

    Ley, J. de; Stouthamer, A.J.

    1959-01-01

    In our strain of Acetobacter suboxydans, three enzymes are present for the oxidation of gluconate: 1. (1) a soluble TPN-specific dehydrogenase, yielding 2-ketogluconate (2-ketogluconoreductase); 2. (2) a soluble TPN-specific dehydrogenase, yielding 5-ketogluconate (5-ketogluconoreductase); 3. (3

  3. Localization of cellulose synthase in Acetobacter xylinum

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    Bureau, T.E.

    1987-01-01

    The cytoplasmic and outer membranes of Acetobacter xylinum (ATCC 53582) were isolated by discontinuous sucrose density ultracentrifugation. Both lysozyme and trypsin were required for efficient crude membrane separation. Primary dehydrogenases and NADH oxidase were used as cytoplasmic membrane markers, and 2-keto-3-deoxy-octulosonic acid was used to identify the outer membranes. Cellulose synthetase activity was assayed as the conversion of radioactivity from UDP-(/sup 14/C)glucose into an alkali-insoluble ..beta..-1,4-D-(/sup 14/C)glucan. The cellulosic nature of the product was demonstrated by enzymatic hydrolysis followed by thin-layer chromatography, and by methylation analysis followed by thin-layer chromatography and gas chromatography-mass spectroscopy. X-ray diffraction analysis indicated that the in vitro product is cellulose II which is in contrast to the in vivo product, namely cellulose I. In addition, no microfibrillar morphology could be observed from negative stained and metal shadowed preparations of the in vitro product.

  4. Genetic organization of the cellulose synthase operon in Acetobacter xylinum.

    OpenAIRE

    Wong, H C; Fear, A L; Calhoon, R D; Eichinger, G H; Mayer, R; Amikam, D; Benziman, M; Gelfand, D H; Meade, J H; Emerick, A W

    1990-01-01

    An operon encoding four proteins required for bacterial cellulose biosynthesis (bcs) in Acetobacter xylinum was isolated via genetic complementation with strains lacking cellulose synthase activity. Nucleotide sequence analysis indicated that the cellulose synthase operon is 9217 base pairs long and consists of four genes. The four genes--bcsA, bcsB, bcsC, and bcsD--appear to be translationally coupled and transcribed as a polycistronic mRNA with an initiation site 97 bases upstream of the co...

  5. Acetobacter aceti fast identification by Real Time PCR in spoiled wine samples

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    Attila Kántor

    2014-11-01

    Full Text Available Wine is a beverage that made from grape berries. However, without beneficial bacteria, we would not produce good wine. But very often wines contain acetic acid bacteria, which are undesirable in winemaking process. Acetic acid bacteria as known as a vinegar bacteria are Gram-negative, aerobic, rod-shaped and ubiquitous bacteria. This study was focused on species of acetic acid bacteria, specifically Acetobacter aceti that make spoilage in wine.The aim of our study was the identification of Acetobacter aceti in spoiled red wine samples, with plate dilution method on agar plates and using sensitive Real-time PCR (qPCR method. We cultivated Acetobacter aceti on GYC agar at 30°C, 48h. The one of main objective in the present work was the test fast, sensitive and reliable technique such as quantitative Real-time PCR and detecting the presence of Acetobacter aceti in wine samples with positive Acetobacteraceti control on amplification plot and melting curve. The next objective before  qPCR analysis was DNA extraction from wine samples incubated for one week at 28°C aerobically. We used five different red wine samples for this experiment: Alibernet 2013, Blaufränkisch 2013, Cabernet Sauvignon 2013, Dunaj 2012 and Saint-Laurent 2012. Next we extracted DNA from wine samples and from pure Acetobacter aceti CCM 3620T strain purchased from Czech collection of microorganisms in Brno. Susceptibility ofAcetobacter aceti was varied in different isolates from 102 to 107 CFU.mL-1. The number of Acetobacter cells on GYC medium ranged from 4.05 to 4.83log CFU.mL-1 in differentwine samples.The higher number of Acetobacter cells (4.83 log CFU.mL-1 was found in Cabernet Sauvignon 2013 wine.

  6. Inkorporasi Asam Askorbat pada Pembentukan Selulosa Bakteri Dengan Menggunakan Acetobacter xylinum

    OpenAIRE

    Yusak, Yuniarti

    2012-01-01

    Incorporation of ascorbic acid at forming bacterial cellulose by using Acetobacter xylinum. Coconut water as a substance, use for making bacterial cellulose thrugh phosphate pentose pathway with juice Acetobacter xylinum bacteria and it was used for making starter. And starter of coconut water used to synthesize bacterial cellulose . Making of bacterial cellulose by ascorbic acid various 0, 0,5, 1,0 ,1,5 and 2,0 gram from cellulose for fourteen days. The product was pr...

  7. Role of Plasmid in Production of Acetobacter Xylinum Biofilms

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    Abbas Rezaee

    2005-01-01

    Full Text Available Acetobacter xylinum has the ability to produce cellulotic biofilms. Bacterial cellulose is expected to be used in many industrial or biomedical materials for its unique characteristics. A. xylinum contains a complex system of plasmid DNA molecules. A 44 kilobases (kb plasmid was isolated in wild type of A. xylinum. To improve the cellulose producing ability of A. xylinum, role of the plasmid in production of cellulose was studied. The comparisons between wild type and cured cells of A. xylinum showed that there is considerably difference in cellulose production. In order to study the relationship between plasmid and the rate of cellulose production, bacteria were screened for plasmid profile by a modified method for preparation of plasmid. This method yields high levels of pure plasmid DNA that can be used for common molecular techniques, such as digestion and transformation, with high efficiency.

  8. Anticorrosive Influence of Acetobacter aceti Biofilms on Carbon Steel

    Science.gov (United States)

    France, Danielle Cook

    2016-07-01

    Microbiologically influenced corrosion (MIC) of carbon steel infrastructure is an emerging environmental and cost issue for the ethanol fuel industry, yet its examination lacks rigorous quantification of microbiological parameters that could reveal effective intervention strategies. To quantitatively characterize the effect of cell concentration on MIC of carbon steel, numbers of bacteria exposed to test coupons were systematically controlled to span four orders of magnitude throughout a seven-day test. The bacterium studied, Acetobacter aceti, has been found in ethanol fuel environments and can convert ethanol to the corrosive species acetic acid. A. aceti biofilms formed during the test were qualitatively evaluated with fluorescence microscopy, and steel surfaces were characterized by scanning electron microscopy. During exposure, biofilms developed more quickly, and test reactor pH decreased at a faster rate, when cell exposure was higher. Resulting corrosion rates, however, were inversely proportional to cell exposure, indicating that A. aceti biofilms are able to protect carbon steel surfaces from corrosion. This is a novel demonstration of corrosion inhibition by an acid-producing bacterium that occurs naturally in corrosive environments. Mitigation techniques for MIC that harness the power of microbial communities have the potential to be scalable, inexpensive, and green solutions to industrial problems.

  9. Characterization of cellulose membranes produced by Acetobacter xyllinum

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    Pikul Wanichapichart

    2002-11-01

    Full Text Available Cellulose membranes formed by Acetobacter xylinum under known cell density in a culture medium were characterized. A dead end testing unit was used for water flux and filtration of Chlorella sp. and bovine serum albumin (BSA. This study found that the cells formed membranes faster in sucrose supplemented coconut juice than in the standard Schramm & Hestrin's medium. For two-day formed membranes in the former medium, an increase in cell density from 1 × 108 to 2 × 108 cfu.ml-1 reduced water flux and, hence, reduced the hydraulic permeability coefficient (Lp from 3.6 × 10-10 to 0.5 × 10-10 m3N-1s-1. These membranes were asymmetric-hydrophilic type with thickness less than 6.0 μm. Membrane porosity was found to vary from 1.4% to 2.4%, with the averaged pore size 0.08 μm. Under 100 kPa filtration, two-day formed membranes in sucrose supplemented coconut juice with higher cell density rejected Chlorella cells and BSA by 99.8% and 98.4%, respectively.

  10. Immobilization of Acetobacter aceti on cellulose ion exchangers: adsorption isotherms

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    Bar, R.; Gainer, J.L.; Kirwan, D.J.

    1986-08-01

    The adsorptive behavior of cells of Acetobacter aceti, ATCC 23746, on DEAE-, TEAE-, and DEHPAE-cellulose ion exchangers in a modified Hoyer's medium at 30 degrees Centigrade was investigated. The maximum observed adsorption capacities varied from 46 to 64 mg dry wt/g resin. The Langmuir isotherm form was used to fit the data, since the cells formed a monolayer on the resin and exhibited saturation. The equilibrium constant in the Langmuir expression was qualitatively correlated with the surface charge density of the resin. The adsorption was also ''normalized'' by considering the ionic capacities of the resins. The exceptionally high normalized adsorption capacity of ECTEOLA-cellulose, 261 mg dry/meq, may be explained by an interaction between the cell wall and the polyglyceryl chains of the exchanging groups in addition to the electrostatic effects. The effect of pH on the bacterial adsorption capacity of ECTEOLA-, TEAE-, and phosphate-cellulose resins was studied and the pH of the bacteria was estimated to be 3.0. 17 references.

  11. Anticorrosive Influence of Acetobacter aceti Biofilms on Carbon Steel

    Science.gov (United States)

    France, Danielle Cook

    2016-09-01

    Microbiologically influenced corrosion (MIC) of carbon steel infrastructure is an emerging environmental and cost issue for the ethanol fuel industry, yet its examination lacks rigorous quantification of microbiological parameters that could reveal effective intervention strategies. To quantitatively characterize the effect of cell concentration on MIC of carbon steel, numbers of bacteria exposed to test coupons were systematically controlled to span four orders of magnitude throughout a seven-day test. The bacterium studied, Acetobacter aceti, has been found in ethanol fuel environments and can convert ethanol to the corrosive species acetic acid. A. aceti biofilms formed during the test were qualitatively evaluated with fluorescence microscopy, and steel surfaces were characterized by scanning electron microscopy. During exposure, biofilms developed more quickly, and test reactor pH decreased at a faster rate, when cell exposure was higher. Resulting corrosion rates, however, were inversely proportional to cell exposure, indicating that A. aceti biofilms are able to protect carbon steel surfaces from corrosion. This is a novel demonstration of corrosion inhibition by an acid-producing bacterium that occurs naturally in corrosive environments. Mitigation techniques for MIC that harness the power of microbial communities have the potential to be scalable, inexpensive, and green solutions to industrial problems.

  12. Unique regulatory properties of the UDP-glucose:. beta. -1,4-glucan synthetase of Acetobacter xylinum. [Acetobacter xylinum

    Energy Technology Data Exchange (ETDEWEB)

    Benziman, M.; Aloni, Y.; Delmer, D.P.

    1983-01-01

    Conditions have been found for an extremely efficient transfer of glucose from UDP-glucose to a cellulosic ..beta..-1,4-glucan product, using enzyme preparations derived from cells of Acetobacter xylinum. Membrane fractions obtained by rupturing cells in the presence of 20% (w/v) polyethylene glycol-4000 (PEG-4000) exhibited UDP-glucose:..beta..-1,4-glucan synthetase activity 3- to 10-fold higher than those previously reported. Enzyme prepared in this fashion also shows a further marked activation by GTP. The activation (apparent K/sub alpha/ = 35 ..mu..M) is quite specific for GTP. A variety of other nucleotides and nucleotide derivatives had no effect on activity. Guanosine-5'-(lambda-thio)triphosphate, an analog of GTP, is even more efficient than GTP (K/sub alpha/ = 17 ..mu..M). Enzyme prepared in the absence of PEG-4000 does not respond to GTP because it lacks a protein factor essential for GTP activation. PEG-4000 promotes the interaction of the protein factor with the enzyme. The factor itself is devoid of synthetase activity and does not stimulate activity of the enzyme in the absence of GTP. Under optimal conditions, in the presence of GTP, factor, and PEG-4000, initial rates of enzyme activity that are 200 times higher than those previously reported can be achieved. Such rates exceed 40% of the in vivo rate of cellulose synthesis from glucose. 26 references, 3 figures, 3 tables.

  13. THE INFLUENCE OF CULTURE MEDIA ON ACETIC FERMENTATION WITH SELECTED Acetobacter STRAINS

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    MARIA CRISTIANA GARNAI

    2012-06-01

    Full Text Available We have systematically followed the efficiency of acetic fermentation, by cultivating 14 Acetobacter strains (previously isolated and identified, within a medium obtain out of ethanol and acetic acid, in various proportions, and utilizing corn extract (CE as a nutrient. The purpose of the research was to determine the resistance of the studied Acetobacter strains related to the composition of the cultivation media (acidity and alcohol content of the medium, as well as following the dynamics of the acetic fermentation by calculating the practical yield. The research led to optimal variants which may be industrially exploited in order to obtain vinegar.

  14. Assessment of the contribution of cocoa-derived strains of Acetobacter ghanensis and Acetobacter senegalensis to the cocoa bean fermentation process through a genomic approach.

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    Illeghems, Koen; Pelicaen, Rudy; De Vuyst, Luc; Weckx, Stefan

    2016-09-01

    Acetobacter ghanensis LMG 23848(T) and Acetobacter senegalensis 108B are acetic acid bacteria that originate from a spontaneous cocoa bean heap fermentation process and that have been characterised as strains with interesting functionalities through metabolic and kinetic studies. As there is currently little genetic information available for these species, whole-genome sequencing of A. ghanensis LMG 23848(T) and A. senegalensis 108B and subsequent data analysis was performed. This approach not only revealed characteristics such as the metabolic potential and genomic architecture, but also allowed to indicate the genetic adaptations related to the cocoa bean fermentation process. Indeed, evidence was found that both species possessed the genetic ability to be involved in citrate assimilation and displayed adaptations in their respiratory chain that might improve their competitiveness during the cocoa bean fermentation process. In contrast, other properties such as the dependence on glycerol or mannitol and lactate as energy sources or a less efficient acid stress response may explain their low competitiveness. The presence of a gene coding for a proton-translocating transhydrogenase in A. ghanensis LMG 23848(T) and the genes involved in two aromatic compound degradation pathways in A. senegalensis 108B indicate that these strains have an extended functionality compared to Acetobacter species isolated from other ecosystems. PMID:27217361

  15. Transformation of microorganisms with the plasmid vector with the replicon from pAC1 from Acetobacter pasteurianus.

    Science.gov (United States)

    Grones, J; Turna, J

    1995-01-26

    A number of gram-negative and gram-positive bacteria species was screened for the expression of the gram-negative plasmid pACK5 and pACT72 with replicon of pAC1 plasmid from Acetobacter pasteurianus. As was described previously, both plasmids were expressed in Escherichia coli, Acetobacter pasteurianus, Acetobacter aceti, Shigella spp. and Citrobacter spp. Expressions of plasmids were successful in twelve species tested, Comamonas terrigena, Salmonella typhimurium, Serratia marcescens, Bacillus cereus, Bacillus megatericum, Bacillus subtilis, Lactobacillus helveticus, Micrococcus luteus, Sarcina lutea, Staphylococcus aureus, Staphylococcus epidermidis, Streptoccocus feacalis, and the stability of plasmid DNA was tested after cultivation in non-selective conditions. PMID:7832808

  16. Draft Genome Sequence of Acetobacter malorum CECT 7742, a Strain Isolated from Strawberry Vinegar.

    Science.gov (United States)

    Sainz, Florencia; Mas, Albert; Torija, María Jesús

    2016-06-23

    The present article reports the draft genome sequence of the strain Acetobacter malorum CECT 7742, an acetic acid bacterium isolated from strawberry vinegar. This species is characterized by the production of d-gluconic acid from d-glucose, which it further metabolizes to keto-d-gluconic acids.

  17. Draft Genome Sequence of Acetobacter malorum CECT 7742, a Strain Isolated from Strawberry Vinegar

    Science.gov (United States)

    Sainz, Florencia; Torija, María Jesús

    2016-01-01

    The present article reports the draft genome sequence of the strain Acetobacter malorum CECT 7742, an acetic acid bacterium isolated from strawberry vinegar. This species is characterized by the production of d-gluconic acid from d-glucose, which it further metabolizes to keto-d-gluconic acids. PMID:27340078

  18. Draft Genome Sequence of Acetobacter malorum CECT 7742, a Strain Isolated from Strawberry Vinegar.

    Science.gov (United States)

    Sainz, Florencia; Mas, Albert; Torija, María Jesús

    2016-01-01

    The present article reports the draft genome sequence of the strain Acetobacter malorum CECT 7742, an acetic acid bacterium isolated from strawberry vinegar. This species is characterized by the production of d-gluconic acid from d-glucose, which it further metabolizes to keto-d-gluconic acids. PMID:27340078

  19. Effect of tungsten concentration on growth of acetobacter xylinum as a promising agent for eco-friendly recycling system

    Science.gov (United States)

    Nandiyanto, A. B. D.; Halimatul, H. S.; Rosyid, N. H.; Effendi, D. B.

    2016-04-01

    Effect of tungsten (W) concentration on Acetobacter xylinum growth was studied. In the experimental procedure, concentration of W in the bacterial growth medium containing pineapple peels waste was varied from 0.5 to 50 ppm. To confirm the influence of W, the bacterial incubation process was carried out for 72 hours. Spectrophotometer analysis showed that the growth rate of Acetobacter xylinum decreased with increasing concentration of W. The result from fourier transform infra red analysis showed a slightly change on the absorption peak intensities and informing the interaction of W ion and bacteria cell. The result confirmed that Acetobacter xylinum was able to uptake W concentration up to 15 ppm, indicating that Acetobacter xylinum might act as a promising agent for eco-friendly recycling system.

  20. Removal of Mercury from chlor-alkali Industry Wastewater using Acetobacter xylinum Cellulose

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    A. Rezaee

    2005-01-01

    Full Text Available In this study, the removal of mercury ions by cellulose of Acetobacter xylinum was investigated in the synthetic and chlor-alkali wastewater. Biofilms of Acetobacter xylinum were grown in laboratory column bioreactors. The biofilms were continuously treated with sterile synthetic model wastewater or nonsterile, neutralized chloralkali wastewater.The extent of adsorption was studied as function of pH, adsorbent dose and contact time. Efficiency of mercury ion removal from chlor-alkali industry wastewater by aluminum sulfate and ferric chloride was also determined. Under acidic condition the adsorption of mercury by cellulose was quite low and increasing processing time more than 10min has no remarkably effect on the adsorption rate. Adsorption capacity of cellulose under dynamic condition for chlor-alkali wastewater was 65mg/µg which was less than the value (80mg/µg that obtained from batch adsorption experiments for synthetic wastewater.

  1. APPLICATION OF RT-PCR FOR ACETOBACTER SPECIES DETECTION IN RED WINE

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    Attila Kántor

    2014-02-01

    Full Text Available Acetic acid bacteria play a negative role in wine making because they increase the volatile acidity of wines. They can survive in the various phases of alcoholic fermentation and it is very important to control their presence and ulterior development. The main objective of the present work is to test fast, sensitive and reliable technique such as real-time PCR (rt-PCR and detecting the presence of Acetobacter aceti, Acetobacter pasteurianus, Gluconobacter oxydans, Gluconacetobacter liquefaciens and Gluconacetobacter hansenii in red wine. The aim of our study was the identification of some species of acetic acid bacteria in red wine during the fermentation process using a classical microbiological method. The changes in different groups of microorganisms were monitored in total counts of bacteria, and Acetobacter cells. Microbiological parameters were observed during the current collection and processing of wine in 2012. Samples (Modry Portugal, MP and Frankovka modra, FM were taken during the fermentation process in wine enterprises and were storage with different conditions. The total counts of bacteria ranged from 4.21 in the wine MP at 4°C of storage to 5.81 log CFU.mL-1 in the wine MP at 25°C of storage, but the total counts of bacteria ranged from 4.85 in the wine FM at 4°C of storage to 5.63 log CFU.mL-1 in the wine FM at 25°C of storage. The higher number of Acetobacter cells was found in wine MP at 25°C.

  2. Location and limitation of cellulose production by Acetobacter xylinum established from oxygen profiles

    NARCIS (Netherlands)

    Verschuren, P.G.; Cardona, T.D.; Nout, M.J.R.; Gooijer, de K.D.; Heuvel, van den J.C.

    2000-01-01

    The static fermentation of coconut water sucrose by Acetobacter xylinum was carried out at initial pH's of 3.0, 4.0, 5.0 or 6.0. Cellulose was produced at the surface, and its production was most favourable at pH's 4.0 and 5.0. These pH values also allowed for optimal bacterial growth. Oxygen concen

  3. Study of acetic acid production by immobilized acetobacter cells: oxygen transfer

    Energy Technology Data Exchange (ETDEWEB)

    Ghommidh, C.; Navarro, J.M.; Durand, G.

    1982-03-01

    The immobilization of living Acetobacter cells by adsorption onto a large-surface-area ceramic support was studied in a pulsed flow reactor. The high oxygen transfer capability of the reactor enabled acetic acid production rates up to 10.4 g/L/h to be achieved. Using a simple mathematical model incorporating both internal and external mass transfer coefficients, it was shown that oxygen transfer in the microbial film controls the reactor productivity. (Refs. 10).

  4. Cellulose Assemblies Produced by Acetobacter Xylinum (FUNDAMENTAL MATERIAL PROPERTIES-Molecular Dynamic Characteristics)

    OpenAIRE

    Hirai, Asako; Horii, Fumitaka

    2000-01-01

    Structures of cellulose assemblies produced by Acetobacter xylinum under various conditions have been studied mainly by transmission electron microscopy. Native cellulose crystals are composites of cellulose Iα and Iβ . Twisted-ribbn cellulose assemblies produced in the HS medium at 28 °C were rich in cellulose Iα . On the contrary, splayed microfibrils produced in the presence of CMC at 28 °C were rich in Iβ . Not only the ribbon assembly but also the bundle of splayed microfibrils was deter...

  5. Synthesis of cellulose by Acetobacter xylinum. VI. Growth on citric acid-cycle intermediates.

    Science.gov (United States)

    GROMET-ELHANAN, Z; HESTRIN, S

    1963-02-01

    Gromet-Elhanan, Zippora (The Hebrew University, Jerusalem, Israel) and Shlomo Hestrin. Synthesis of cellulose by Acetobacter xylinum. VI. Growth on citric acid-cycle intermediates. J. Bacteriol. 85:284-292. 1963.-Acetobacter xylinum could be made to grow on ethanol, acetate, succinate, or l-malate. The growth was accompanied by formation of opaque leathery pellicles on the surface of the growth medium. These pellicles were identified as cellulose on the basis of their chemical properties, solubility behavior, and infrared absorption spectra. Washed-cell suspensions prepared from cultures grown on ethanol or the organic acids, in contrast to washed sugar-grown cells, were able to transform citric-cycle intermediates into cellulose. The variations in the substrate spectrum of cellulose synthesis between sugar-grown cells and organic acids-grown cells were found to be correlated with differences in the oxidative capacity of the cells. The significance of the findings that A. xylinum could be made to grow on ethanol on complex as well as synthetic media is discussed from the viewpoint of the whole pattern of Acetobacter classification.

  6. Studying on the pde-gene′s disruption of the Acetobacter xy linum%醋酸杆菌 Acetobacter xylinum pde 基因敲除研究

    Institute of Scientific and Technical Information of China (English)

    张雯; 齐香君; 李彦军

    2013-01-01

    基于磷酸二酯酶(PDE)对细菌纤维素(BC)合成产生抑制的机理,对细菌纤维素生产菌株醋酸杆菌(Acetobacter xylinum)的PDE编码基因(pde基因)进行了基因敲除研究,构建PDE失活型(PDE -)重组菌株,并通过氨苄青霉素及氯霉素抗生素培养基筛选出目的重组菌株。发酵及遗传稳定性实验结果表明,PDE -重组菌株发酵生产BC产量比出发菌株最大可提高38%,且遗传性能稳定。本研究为提高BC发酵产量奠定了基础。%According to the mechanism that the phosphodiesterase(PDE) would restrain the synthesis of bacterial cellulose(BC) ,pde-gene which code PDE in the Acetobacter xylinum producing BC is disrupted ,and new strains named PDE - strain w hose PDE have non-activity are constructed .The aim strains are filtrated using the culture medium which contains ampi-cillin and chloromycetin .The results of the fermentation shows that the BC output of PDE -strain can increased by 38% than the starting strain ,and its heredity was stable .This study has laid certain foundation to increase the fermentation output of BC .

  7. Assimilation of methanol by an acidophilic bacterium of the genus Acetobacter

    Energy Technology Data Exchange (ETDEWEB)

    Babel, W.

    1984-01-01

    The assimilation of methanol can take place via several pathways. Acetobacter methanolicus prefers an acidic pH range for growth. The latter is interesting from a regulatory point of view because phosphofructokinase disappears during growth on glucose, which is assimilated via the hexosemonophosphate pathway. Although A. methanolicus uses the hexulosephosphate pathway the growth yield on methanol is smaller than with other 'hexulosephosphate pathway bacteria' e.g. with obligate methanol assimilating bacteria. The relationship between the dependence on and the protection from, high external proton concentration on the one hand and the causes of the low growth yield on the other are discussed.

  8. Isolation and Identification of Acetobacter Bacteria from Kefir Grains%开菲尔粒中醋酸菌的分离鉴定

    Institute of Scientific and Technical Information of China (English)

    刘芸; 曹宜; 刘波; 刘丹莹; 朱育菁; 刘欣

    2012-01-01

    Two Acetobacter strains FJAT-13764 and FJAT-13780 were isolated from kefir grains. The observations with scanning electron microscope showed that both bacteria strains were rod-shaded with round terminals, presented in single or pairs, produced no spores. Their orerall biochemical and physiological characters indicated that these strains should be placed in the Acetobacter spp. The 16S rDNA sequence analysis indicated that FJAT-13764 and FJAT-13780 were Acetobacter orientalis and Acetobacter syzygii, respectively. This study is the first report in Acetobacter orientalis isolated from kefir grains, which provides the basic information for further researches on the micro-flora diversity in kefir grain.%从开菲尔粒中分离出2株醋酸菌FJAT-13764和FJAT-13780.利用形态学观察、生理生化和16S rDNA方法对菌株进行分类鉴定.菌株FJAT-13764和FJAT-13780的菌体形态均为圆端直杆菌,单个或成对,无芽孢,其生理生化特征与醋杆菌属Acetobacter基本一致.经16S rDNA基因序列同源性比较和系统发育分析,鉴定菌株FJAT-13764为Acetobacter orientalis(东方醋酸菌),菌株FJAT-13780为Acetobacter syzygii.

  9. Bacterial Cellulose Production by Acetobacter xylinum Strains from Agricultural Waste Products

    Science.gov (United States)

    Kongruang, Sasithorn

    Bacterial cellulose is a biopolysaccharide produced from the bacteria, Acetobacter xylinum. Static batch fermentations for bacterial cellulose production were studied in coconut and pineapple juices under 30 °C in 5-1 fermenters by using three Acetobacter strains: A. xylinum TISTR 998, A. xylinum TISTR 975, and A. xylinum TISTR 893. Experiments were carried out to compare bacterial cellulose yields along with growth kinetic analysis. Results showed that A. xylinum TISTR 998 produced a bacterial cellulose yield of 553.33 g/l, while A. xylinum TISTR 893 produced 453.33 g/l and A. xylinum TISTR 975 produced 243.33 g/l. In pineapple juice, the yields for A. xylinum TISTR 893, 975, and 998 were 576.66, 546.66, and 520 g/l, respectively. The strain TISTR 998 showed the highest productivity when using coconut juice. Morphological properties of cellulose pellicles, in terms of texture and color, were also measured, and the textures were not significantly different among treatments.

  10. Comparative Proteome of Acetobacter pasteurianus Ab3 During the High Acidity Rice Vinegar Fermentation.

    Science.gov (United States)

    Wang, Zhe; Zang, Ning; Shi, Jieyan; Feng, Wei; Liu, Ye; Liang, Xinle

    2015-12-01

    As a traditional Asian food for several centuries, vinegar is known to be produced by acetic acid bacteria. The Acetobacter species is the primary starter for vinegar fermentation and has evolutionarily acquired acetic acid resistance, in which Acetobacter pasteurianus Ab3 is routinely used for industrial production of rice vinegar with a high acidity (9 %, w/v). In contrast to the documented short-term and low acetic acid effects on A. pasteurianus, here we investigated the molecular and cellular signatures of long-term and high acetic acid responses by proteomic profiling with bidimensional gel electrophoresis and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI TOF/MS) analyses. Protein spots of interest were selected based on the threshold ANOVA p value of 0.05 and minimal twofold of differential expression, leading to the identification of 26 proteins that are functionally enriched in oxidoreductase activity, cell membrane, and metabolism. The alterations in protein functioning in respiratory chain and protein denaturation may underlay cellular modifications at the outer membrane. Significantly, we found that at higher acidity fermentation phase, the A. pasteurianus Ab3 cells would adapt to distinct physiological processes from that of an ordinary vinegar fermentation with intermediate acidity, indicating increasing energy requirement and dependency of membrane integrity during the transition of acetic acid production. Together, our study provided new insights into the adaptation mechanisms in A. pasteurianus to high acetic acid environments and yield novel regulators and key pathways during the development of acetic acid resistance.

  11. Immobilization of Acetobacter sp. CCTCC M209061 for efficient asymmetric reduction of ketones and biocatalyst recycling

    Directory of Open Access Journals (Sweden)

    Chen Xiao-Hong

    2012-09-01

    Full Text Available Abstract Background The bacterium Acetobacter sp. CCTCC M209061 is a promising whole-cell biocatalyst with exclusive anti-Prelog stereoselectivity for the reduction of prochiral ketones that can be used to make valuable chiral alcohols such as (R-4-(trimethylsilyl-3-butyn-2-ol. Although it has promising catalytic properties, its stability and reusability are relatively poor compared to other biocatalysts. Hence, we explored various materials for immobilizing the active cells, in order to improve the operational stability of biocatalyst. Results It was found that Ca-alginate give the best immobilized biocatalyst, which was then coated with chitosan to further improve its mechanical strength and swelling-resistance properties. Conditions were optimized for formation of reusable immobilized beads which can be used for repeated batch asymmetric reduction of 4′-chloroacetophenone. The optimized immobilized biocatalyst was very promising, with a specific activity of 85% that of the free-cell biocatalyst (34.66 μmol/min/g dw of cells for immobilized catalyst vs 40.54 μmol/min/g for free cells in the asymmetric reduction of 4′-chloroacetophenone. The immobilized cells showed better thermal stability, pH stability, solvent tolerance and storability compared with free cells. After 25 cycles reaction, the immobilized beads still retained >50% catalytic activity, which was 3.5 times higher than degree of retention of activity by free cells reused in a similar way. The cells could be recultured in the beads to regain full activity and perform a further 25 cycles of the reduction reaction. The external mass transfer resistances were negligible as deduced from Damkohler modulus Da η ∅ Conclusions Ca-alginate coated with chitosan is a highly effective material for immobilization of Acetobacter sp. CCTCC M209061 cells for repeated use in the asymmetric reduction of ketones. Only a small cost in terms of the slightly lower catalytic activity compared to

  12. Isolation and nucleotide sequence of the GDP-mannose:cellobiosyl-diphosphopolyprenol alpha-mannosyltransferase gene from Acetobacter xylinum.

    OpenAIRE

    Petroni, E A; Ielpi, L

    1996-01-01

    A genetic locus from Acetobacter xylinum involved in acetan polysaccharide synthesis has been characterized. The chromosomal region was identified by screening a genomic library of A. xylinum in a Xanthomonas campestris mutant defective in xanthan polysaccharide synthesis. The A. xylinum cosmid clone can functionally complement a xanthan-negative mutant. The polymer produced by the recombinant strain was found to be indistinguishable from xanthan. Insertion mutagenesis and subcloning of the c...

  13. Coffea arabica L., a new host plant for Acetobacter diazotrophicus, and isolation of other nitrogen-fixing acetobacteria.

    OpenAIRE

    Jimenez-Salgado, T; Fuentes-Ramirez, L. E.; Tapia-Hernandez, A; Mascarua-Esparza, M A; Martinez-Romero, E.; Caballero-Mellado, J

    1997-01-01

    Acetobacter diazotrophicus was isolated from coffee plant tissues and from rhizosphere soils. Isolation frequencies ranged from 15 to 40% and were dependent on soil pH. Attempts to isolate this bacterial species from coffee fruit, from inside vesicular-arbuscular mycorrhizal fungi spores, or from mealybugs (Planococcus citri) associated with coffee plants were not successful. Other acid-producing diazotrophic bacteria were recovered with frequencies of 20% from the coffee rhizosphere. These N...

  14. Isolation of a new restriction enzyme, ApaCI, an isoschizomer of BamHI produced by Acetobacter pasteurianus.

    Science.gov (United States)

    Grones, J; Turna, J

    1992-01-01

    A new Type II restriction endonuclease ApaCI purified from Acetobacter pasteurianus is an isoschizomer of BamHI that cleaves at the nucleotide sequence 5'-G/GATCC-3' of double-stranded DNA. The single restriction activity present in this strain permits rapidly purified 30,000 units of cleavage activity from 10 g of freshly harvested cells. The resulting ApaCI preparation is free of contaminant nuclease activities that might interfere with in vitro manipulation of DNA.

  15. Determination of Dehydrogenase Activities Involved in D-Glucose Oxidation in Gluconobacter and Acetobacter Strains.

    Science.gov (United States)

    Sainz, Florencia; Jesús Torija, María; Matsutani, Minenosuke; Kataoka, Naoya; Yakushi, Toshiharu; Matsushita, Kazunobu; Mas, Albert

    2016-01-01

    Acetic acid bacteria (AAB) are known for rapid and incomplete oxidation of an extensively variety of alcohols and carbohydrates, resulting in the accumulation of organic acids as the final products. These oxidative fermentations in AAB are catalyzed by PQQ- or FAD- dependent membrane-bound dehydrogenases. In the present study, the enzyme activity of the membrane-bound dehydrogenases [membrane-bound PQQ-glucose dehydrogenase (mGDH), D-gluconate dehydrogenase (GADH) and membrane-bound glycerol dehydrogenase (GLDH)] involved in the oxidation of D-glucose and D-gluconic acid (GA) was determined in six strains of three different species of AAB (three natural and three type strains). Moreover, the effect of these activities on the production of related metabolites [GA, 2-keto-D-gluconic acid (2KGA) and 5-keto-D-gluconic acid (5KGA)] was analyzed. The natural strains belonging to Gluconobacter showed a high mGDH activity and low activity in GADH and GLDH, whereas the Acetobacter malorum strain presented low activity in the three enzymes. Nevertheless, no correlation was observed between the activity of these enzymes and the concentration of the corresponding metabolites. In fact, all the tested strains were able to oxidize D-glucose to GA, being maximal at the late exponential phase of the AAB growth (24 h), which coincided with D-glucose exhaustion and the maximum mGDH activity. Instead, only some of the tested strains were capable of producing 2KGA and/or 5KGA. In the case of Gluconobacter oxydans strains, no 2KGA production was detected which is related to the absence of GADH activity after 24 h, while in the remaining strains, detection of GADH activity after 24 h resulted in a high accumulation of 2KGA. Therefore, it is possible to choose the best strain depending on the desired product composition. Moreover, the sequences of these genes were used to construct phylogenetic trees. According to the sequence of gcd, gene coding for mGDH, Acetobacter and Komagataeibacter

  16. Determination of Dehydrogenase Activities Involved in D-Glucose Oxidation in Gluconobacter and Acetobacter Strains

    Science.gov (United States)

    Sainz, Florencia; Jesús Torija, María; Matsutani, Minenosuke; Kataoka, Naoya; Yakushi, Toshiharu; Matsushita, Kazunobu; Mas, Albert

    2016-01-01

    Acetic acid bacteria (AAB) are known for rapid and incomplete oxidation of an extensively variety of alcohols and carbohydrates, resulting in the accumulation of organic acids as the final products. These oxidative fermentations in AAB are catalyzed by PQQ- or FAD- dependent membrane-bound dehydrogenases. In the present study, the enzyme activity of the membrane-bound dehydrogenases [membrane-bound PQQ-glucose dehydrogenase (mGDH), D-gluconate dehydrogenase (GADH) and membrane-bound glycerol dehydrogenase (GLDH)] involved in the oxidation of D-glucose and D-gluconic acid (GA) was determined in six strains of three different species of AAB (three natural and three type strains). Moreover, the effect of these activities on the production of related metabolites [GA, 2-keto-D-gluconic acid (2KGA) and 5-keto-D-gluconic acid (5KGA)] was analyzed. The natural strains belonging to Gluconobacter showed a high mGDH activity and low activity in GADH and GLDH, whereas the Acetobacter malorum strain presented low activity in the three enzymes. Nevertheless, no correlation was observed between the activity of these enzymes and the concentration of the corresponding metabolites. In fact, all the tested strains were able to oxidize D-glucose to GA, being maximal at the late exponential phase of the AAB growth (24 h), which coincided with D-glucose exhaustion and the maximum mGDH activity. Instead, only some of the tested strains were capable of producing 2KGA and/or 5KGA. In the case of Gluconobacter oxydans strains, no 2KGA production was detected which is related to the absence of GADH activity after 24 h, while in the remaining strains, detection of GADH activity after 24 h resulted in a high accumulation of 2KGA. Therefore, it is possible to choose the best strain depending on the desired product composition. Moreover, the sequences of these genes were used to construct phylogenetic trees. According to the sequence of gcd, gene coding for mGDH, Acetobacter and Komagataeibacter

  17. 藏灵菇发酵乳中醋酸菌的分离纯化与鉴定%Isolation and Identification of Acetobacter in Tibetan Kefir

    Institute of Scientific and Technical Information of China (English)

    曹宜; 刘芸; 刘波; 朱育菁; 陈倩倩

    2012-01-01

    One Acetobacter strain, FJAT-13797, was isolated from Tibetan kefir. The image under scanning electronic microscope showed that the bacterium was rod-shaped with round ends, and presented in single or pairs without spores. The strain showed the bio-chemical properties of Acetobacter spp. The 16S rDNA sequence analysis indicated that the strain, FJAT-13797, belonged to Acetobacter orientalis.%从藏灵菇中分离出醋酸菌株FJAT-13797,利用形态学观察、生理生化和16S rDNA方法对其进行细菌学鉴定,菌体形态为圆端直杆,单个或成对,无芽孢,其生理生化特征与醋杆菌属(Acetobacter)基本一致.经16S rDNA基因序列同源性比较和系统发育分析,菌株FJAT-13797鉴定为东方醋酸菌(Acetobacter orientalis).

  18. Antioxidant and anti-inflammatory levan produced from Acetobacter xylinum NCIM2526 and its statistical optimization.

    Science.gov (United States)

    Srikanth, Rapala; Siddartha, Gudimalla; Sundhar Reddy, Chinta H S S; Harish B S; Janaki Ramaiah, M; Uppuluri, Kiran Babu

    2015-06-01

    Levan is a homopolymer of fructose naturally obtained from both the plants and microorganisms. Along with the general properties of a biopolymer like bio-compatibility, bio-degradability, renewability, flexibility, and eco-friendliness, levan also offers some important biomedical properties such as anti-oxidant, anti-inflammatory, anti-carcinogenic, anti-AIDS and hyperglycaemic inhibitor. In this study, we have demonstrated the microbial production of therapeutically potential levan by batch fermentation process in sucrose rich medium using Acetobacter xylinum NCIM 2526. The produced Levan was characterized using various physicochemical techniques such as FTIR, (1)H NMR, (13)C NMR spectroscopy, TGA and HPLC. The biomedical potential of the isolated A. xylinum levan for its anti-oxidant and anti-inflammatory activities was exploited in vitro. Further the present study also focused on the optimization of levan production using one factor at a time approach followed by a statistical method, central composite design (CCD) with selected variables. The yield of levan was increased significantly from 0.54 to 13.25g/L with the optimized variables. PMID:25843829

  19. Characterization of the acetyl-CoA synthetase of Acetobacter aceti.

    Science.gov (United States)

    O'Sullivan, J; Ettlinger, L

    1976-12-20

    The acetate activating system of Acetobacter aceti has been studied. The enzyme responsible, acetyl-CoA synthetase, has been purified about 500-fold from crude cell extracts and was approximately 85% pure as judged by polyacrylamide gel electrophoresis in sodium dodecyl sulphate. The purified enzyme showed optimal activity at pH 7.6 in both Tris-HCL and potassium phosphate buffers. In its purest form, the enzyme was stable at 4 degrees-C but denatured upon freezing. The Km values for CoA, ATP and acetate were found to be 0.104 mM, 0.36 mM and 0.25 mM respectively; propionate and acrylate were also activated by the enzyme but not butyrate, isobutyrate or valerate. GTP, UTP, CTP and ADP could not replace ATP in the reaction, and cysteine or pantetheine failed to replace CoA. The cationic requirements were studied and of the divalent cations tested, only Mn2+ could significantly replace Mg2+ in the reaction; K+ and NH4+ stimulated enzyme activity but inhibited at high concentrations; Na+ was a poor activator, but did not inhibit at higher concentrations. The effect of a number of glucose and other metabolites on enzyme activity has been tested. PMID:12800

  20. Minerals consumption by Acetobacter xylinum on cultivation medium on coconut water

    Directory of Open Access Journals (Sweden)

    Denise Milleo Almeida

    2013-01-01

    Full Text Available The objective of this work is to verifying the consume of the minerals K, Na, Fe, Mg, P, S-SO4-2,B,N Total Kjedahl (NTK, NO3--N, and NH4+-N in the production of bacterial cellulose by Acetobacter xylinum, according to the medium and the manner of cultivation. The fermentative process was in ripe and green coconut water. K and Na were determined by flame emission photometry, Mg and Fe by atomic absorption spectrophotometry, P by molecular absorption spectrophotometry, S-SO4-2 by barium sulphate turbidimetry, B by Azomethin-H method, NTK by Kjeldahl method, N-NO3-and N-NH4+ by vapor distillation with magnesium oxide and Devarda's alloy, respectively. In Fermentation of ripe coconut water there were higher consumption of K (69%, Fe (84,3%, P (97,4%, S-SO2-2 (64,9%, B (56,1%, N-NO3 (94,7% and N-NH4+ (95,2%, whereas coconut water of green fruit the most consumed ions were Na (94,5%, Mg (67,7% and NTK (56,6%. The cultivation under agitation showed higher mineral consumption. The higher bacterial cellulose production, 6 g.L-1, was verified in the coconut water fermentative in ripe fruit, added KH2PO4, FeSO4 and NaH2PO4 kept under agitation.

  1. Minerals consumption by Acetobacter xylinum on cultivation medium on coconut water.

    Science.gov (United States)

    Almeida, Denise Milleo; Prestes, Rosilene Aparecida; da Fonseca, Adriel Ferreira; Woiciechowski, Adenise L; Wosiacki, Gilvan

    2013-01-01

    The objective of this work is to verifying the consume of the minerals K, Na, Fe, Mg, P, S-SO4 (-2), B, N Total Kjedahl (NTK), NO3 (-)-N, and NH4 (+)-N in the production of bacterial cellulose by Acetobacter xylinum, according to the medium and the manner of cultivation. The fermentative process was in ripe and green coconut water. K and Na were determined by flame emission photometry, Mg and Fe by atomic absorption spectrophotometry, P by molecular absorption spectrophotometry, S-SO4 (-2) by barium sulphate turbidimetry, B by Azomethin-H method, NTK by Kjeldahl method, N-NO3 (-) and N-NH4 (+) by vapor distillation with magnesium oxide and Devarda's alloy, respectively. In Fermentation of ripe coconut water there were higher consumption of K (69%), Fe (84,3%), P (97,4%), S-SO2 (-2) (64,9%), B (56,1%), N-NO3 (-) (94,7%) and N-NH4 (+) (95,2%), whereas coconut water of green fruit the most consumed ions were Na (94,5%), Mg (67,7%) and NTK (56,6%). The cultivation under agitation showed higher mineral consumption. The higher bacterial cellulose production, 6 g.L(-1), was verified in the coconut water fermentative in ripe fruit, added KH2PO4, FeSO4 and NaH2PO4 kept under agitation. PMID:24159306

  2. Partial Purification and Characterisation of Alcohol Dehydrogenase from Acetobacter aceti Isolated from Palm Wine

    Directory of Open Access Journals (Sweden)

    Donatus Chimaobi ONAH

    2016-06-01

    Full Text Available Palm wine is a very important alcoholic beverage whose consumption is limited because it spoils easily. The study was designed to isolate Acetobacter aceti from palm wine, then extract, purify and characterize alcohol dehydrogenase (AD from the A. aceti. Muller Hilton agar was used as medium for the growth of A. aceti for 48 h. The cells were harvested and subjected to ultrasonication using 500 watt ultrasonicator. Enzyme assay was carried out in both the supernatant and pellet. The enzyme was precipitated by polyethelene glycol 6000 while gel filtration was used for purifying the enzyme. The effects of pH, temperature and substrate concentration on AD were evaluated. The isolated A. aceti was gram negative, rod shaped, catalase positive, oxidase negative and was able to oxidize acetic acid to CO2 and H2O. Triton X-100 (0.3% was the most effective concentration in solubilizing the protein (AD, while 15% polyethelene glycol 6000 was the most effective concentration for the precipitation of AD. An optimal pH of 5 was obtained with an optimal temperature of 50 °C. The most appropriate to solubilize and precipitate AD were 0.3% triton X-100 and 15% polyethelene glycol 6000 respectively, while AD activity was reduced under acidic pH, as well as for low and high temperatures.

  3. EVALUASI PENGGUNAAN METILEN BIRU SEBAGAI MEDIATOR ELEKTRON PADA MICROBIAL FUEL CELL DENGAN BIOKATALIS ACETOBACTER ACETI

    Directory of Open Access Journals (Sweden)

    Dani Permana

    2013-05-01

    Full Text Available Microbial fuel cell (MFC merupakan salah satu teknologi sel bahan bakar alternatif yang dapat diperbarui. MFC memanfaatkan proses oksidasi senyawa kimia oleh biokatalis untuk menghasilkan energi listrik daya rendah. Tujuan dari penelitian ini adalah mengetahui kinerja MFC dengan dan tanpa mediator elektron metilen biru (MB menggunakan biokatalis Acetobacter aceti dan substrat glukosa agar diperoleh energi listrik. Metode yang dilakukan adalah peremajaan kultur A. aceti, persiapan inokulum, persiapan reaktor MFC, persiapan media MFC dengan substrat glukosa 2% dengan dan tanpa mediator MB, pencuplikan secara periodik, penentuan kurva pertumbuhan, arus, potensial, kerapatan daya, energi, kadar glukosa dan tingkat keasaman (pH. Hasil penelitian menunjukkan bahwa MFC dengan mediator menghasilkan kuat arus sebesar 0,040 mA, potensial 878 mV, kerapatan daya 0,395 mW/cm2, energi maksimum 3,685 kJ, pemanfaatan glukosa 93,02% dan pH akhir 3,33, sedangkan MFC tanpa mediator menghasilkan kuat arus 0,035 mA, potensial 773 mV, kerapatan daya 0,290 mW/cm2, energi maksimum 2,434 kJ, pemanfaatan glukosa 90,16% dan pH akhir 3,24. Perolehan kerapatan daya pada kedua jenis MFC masih tergolong kecil dan tidak berbeda secara signifikan. Berdasarkan hasil penelitian dapat disimpulkan bahwa penggunaan mediator MB hanya berpengaruh terhadap perolehan potensial pada MFC dengan kondisi perlakuan yang diterapkan dalam penelitian ini.

  4. Production and characterization of nanospheres of bacterial cellulose from Acetobacter xylinum from processed rice bark

    Energy Technology Data Exchange (ETDEWEB)

    Goelzer, F.D.E. [Group of Industrial Microbiology, UNIVALI-Universidade do Vale do Itajai, R. Uruguai, 458, 88302-202, Itajai, Santa Catarina (Brazil); Faria-Tischer, P.C.S. [Group of Industrial Microbiology, UNIVALI-Universidade do Vale do Itajai, R. Uruguai, 458, 88302-202, Itajai, Santa Catarina (Brazil); Laboratory of Biopolymers, UFPR-Universidade Federal do Parana, CxP 19081, 81531-990, Curitiba, Parana (Brazil); Vitorino, J.C. [Group of Industrial Microbiology, UNIVALI-Universidade do Vale do Itajai, R. Uruguai, 458, 88302-202, Itajai, Santa Catarina (Brazil); Sierakowski, Maria-R. [Laboratory of Biopolymers, UFPR-Universidade Federal do Parana, CxP 19081, 81531-990, Curitiba, Parana (Brazil); Tischer, C.A. [Group of Industrial Microbiology, UNIVALI-Universidade do Vale do Itajai, R. Uruguai, 458, 88302-202, Itajai, Santa Catarina (Brazil)], E-mail: cesarat@uol.com.br

    2009-03-01

    Bacterial cellulose (BC), biosynthesized by Acetobacter xylinum, was produced in a medium consisting of rice bark pre-treated with an enzymatic pool. Rice bark was evaluated as a carbon source by complete enzymatic hydrolysis and monosaccharide composition (GC-MS of derived alditol acetates). It was treated enzymatically and then enriched with glucose up to 4% (w/v). The BC produced by static and aerated processes was purified by immersion in 0.1 M NaOH, was characterized by FT-IR, X-ray diffraction and the biosynthetic nanostructures were evaluated by Scanning Electronic (SEM), Transmission Electronic (TEM) and Atomic Force Microscopy (AFM). The BC films arising from static fermentation with rice bark/glucose and glucose are tightly intertwined, partially crystalline, being type II cellulose produced with rice bark/glucose, and type I to the produced in a glucose medium. The nanostructurated biopolymer obtained from the rice bark/glucose medium, produced in a reactor with air flux had micro- and nanospheres linked to nanofibers of cellulose. These results indicate that the bark components, namely lignins, hemicelluloses or mineral contents, interact with the cellulose forming micro- and nanostructures with potential use to incorporate drugs.

  5. Comparison of the mechanism of cellulose biosynthesis in plants and bacteria. [Acetobacter xylinum

    Energy Technology Data Exchange (ETDEWEB)

    Delmer, D.P. (Michigan State Univ., East Lansing); Benziman, M.; Klein, A.S.; Bacic, A.; Mitchell, B.; Weinhouse, H.; Aloni, Y.; Callaghan, T.

    1983-01-01

    Results of recent studies on the mechanism of cellulose biosynthesis in higher plants and in the bacterium Acetobacter xylinum are compared and contrasted. In higher plants, the synthesizing complex is thought to be mobile in the fluid-mosaic plasma membrane, whereas it is stationary in cells of A. xylinum. Similar patterns of sensitivity to inhibitors of cellulose synthesis as well as to changes in transmembrane electrical potential are shared by both plants and A. xylinum. In vivo tracer studies with both types of organisms support the concept the UDP-glucose is a precursor of cellulose. A characterization of additional compounds which may serve as precursors in A. xylinum beyond the level of UDP-glucose is described. UDP-glucose:..beta..-glucan synthetases have been solubilized from plants and A. xylinum. Attempts at purification of solubilized soybean glucan synthetases indicate that a factor(s) is lost during purification which is necessary for activity; studies described elsewhere indicate that the A. xylinum ..beta..-1,4-glucan synthetase requires a protein factor for GTP activation. The stimulatory effect of polyethylene glycol (PEG) on glucan synthetases from both plants and A. xylinum may relate to stabilization by PEG of enzyme-factor associations. 34 references, 3 figures, 3 tables.

  6. Acetobacter tropicalis is a major symbiont of the olive fruit fly (Bactrocera oleae).

    Science.gov (United States)

    Kounatidis, Ilias; Crotti, Elena; Sapountzis, Panagiotis; Sacchi, Luciano; Rizzi, Aurora; Chouaia, Bessem; Bandi, Claudio; Alma, Alberto; Daffonchio, Daniele; Mavragani-Tsipidou, Penelope; Bourtzis, Kostas

    2009-05-01

    Following cultivation-dependent and -independent techniques, we investigated the microbiota associated with Bactrocera oleae, one of the major agricultural pests in olive-producing countries. Bacterial 16S rRNA gene libraries and ultrastructural analyses revealed the presence of several bacterial taxa associated with this insect, among which Acetobacter tropicalis was predominant. The recent increased detection of acetic acid bacteria as symbionts of other insect model organisms, such as Anopheles stephensi (G. Favia et al., Proc. Natl. Acad. Sci. USA 104:9047-9051, 2007) or Drosophila melanogaster (C. R. Cox and M. S. Gilmore, Infect. Immun. 75:1565-1576, 2007), prompted us to investigate the association established between A. tropicalis and B. oleae. Using an A. tropicalis-specific PCR assay, the symbiont was detected in all insects tested originating from laboratory stocks or field-collected from different locations in Greece. This acetic acid bacterium was successfully established in cell-free medium, and typing analyses, carried out on a collection of isolates, revealed that different A. tropicalis strains are present in fly populations. The capability to colonize and lodge in the digestive system of both larvae and adults and in Malpighian tubules of adults was demonstrated by using a strain labeled with a green fluorescent protein.

  7. Identification, sequencing and structural analysis of a nifA-like gene of Acetobacter diazotrophicus.

    Science.gov (United States)

    Teixeira, K R; Morgan, T; Meletzus, D; Galler, R; Baldani, J I; Kennedy, C

    1999-01-01

    A recombinant plasmid, pAD101, containing a DNA fragment of Acetobacter diazotrophicus strain PAL5 was isolated by its ability to restore Nif+ phenotype to a nifA- ntrC- double mutant of Azotobacter vinelandii. Hybridization with the nifA genes of Azospirillum brasilense located the nifA gene more precisely to specific fragments of pAD101. DNA sequencing of appropriate subclones of pAD101 revealed that the nifA gene was adjacent to the nifB gene in A. diazotrophicus, and the 5' end of the nifB gene was located downstream of the nitrogenase MoFe subunit gene, nifK. The deduced aminoacid sequence of A. diazotrophicus nifA and nifB gene were most similar to the NifA and NifB proteins of Azorhizobium caulinodans and Rhodobacter capsulatus, respectively. In addition, nucleotide sequences upstream of the A. diazotrophicus nifA-encoding region indicate features similar to those in the A. caulinodans nifA promoter region involved in O2 and fixed N regulation of nifA expression. PMID:10530336

  8. The optimal conditions for nata production from sugar palm syrup by Acetobacter xylinum TISTR 107

    Directory of Open Access Journals (Sweden)

    Laochareonsuk, T.

    2005-11-01

    Full Text Available The optimal conditions of nata production from the fermentation of sugar palm syrup by Acetobacter xylinum TISTR 107 was studied. The results showed that optimized production for a litre of sugar palm syrup medium should compose 15 ºBrix concentration, 7.0 g NH4H2PO4 and 0.7 g MgSO4. 7 H2O at pH 4.25 and incubation at room temperature. The thickness of nata production reached 1.15 cm in 9 days. Sensory evaluation showed that there were no significant difference in odor and acceptability between the nata from sugar palm syrup and the traditional nata production from coconut juice whereas there were significant differences in color and texture. However, the nata from sugar palm syrup gave a better texture. Chemical analysis of the nata produced under these optimal culture conditions revealed 0.13% protein, 0.012% fat, 2.74% fiber, 0.378% nitrogen-free extract, 0.11% ash and 96.63% moisture content. The results suggest that nata produced from sugar palm syrup can be used in food and confectionery.

  9. Ketahanan Hidup Sel Acetobacter xylinum pada Pengawetan secara Kering-Beku Menggunakan Medium Pembawa (Viability of A. xylinum Subjected to Freeze Drying Using Carrier Media

    Directory of Open Access Journals (Sweden)

    Noor Aini Habibah

    2009-03-01

    Full Text Available A research on the use of sucrose and lactose as carrier media to protect Acetobacter xylinum cell subjected to freeze drying has been done. The aim of the research was to know the number of the viable cells from dried culture and to know the concentration of the carrier medium that would give best result. The best result is sucrose at the concentration of 15% that produced 28.2 x 106 viable cells/ ml of rehidrated culture. The rehidrated culture used in the research was Schramm & Herstin medium. Key words : Acetobacter xylinum, freeze drying, carrier media

  10. A Novel Carbonyl Reductase with Anti-Prelog Stereospecificity from Acetobacter sp. CCTCC M209061: Purification and Characterization

    OpenAIRE

    Xiao-Hong Chen; Ping Wei; Xiao-Ting Wang; Min-Hua Zong; Wen-Yong Lou

    2014-01-01

    A novel carbonyl reductase (AcCR) catalyzing the asymmetric reduction of ketones to enantiopure alcohols with anti-Prelog stereoselectivity was found in Acetobacter sp. CCTCC M209061 and enriched 27.5-fold with an overall yield of 0.4% by purification. The enzyme showed a homotetrameric structure with an apparent molecular mass of 104 kDa and each subunit of 27 kDa. The gene sequence of AcCR was cloned and sequenced, and a 762 bp gene fragment was obtained. Either NAD(H) or NADP(H) can be use...

  11. Acetobacter xylinum NUST4.2摇瓶发酵细菌纤维素的动力学研究%Studies on Fermentation Kinetics of Acetobacter xylinumNUST4.2 Producing Bacterial Cellulose in Shake Flask

    Institute of Scientific and Technical Information of China (English)

    殷智超; 马波; 朱春林; 孙东平

    2011-01-01

    研究了细菌纤维素生产菌株Acetobacter xylinum NUST4.2的发酵动力学特性,建立了基于Logistic方程的菌体生长动力学、产物生成动力学、底物消耗动力学,得到了描述摇瓶发酵过程的动力学模型及模型参数,模型与实验数据拟合良好,反映了该菌株分批发酵过程的动力学特征。%The fermentation kinetics of bacterial cellulose-producting strain Acetobacter xylinum NUST4.2 was studied.A kinetic model was established based on the Logistic equation for cell growth,product formation and substrate consumption during fermentation in shake flask.The model fitted well and gave a reasonable description of the batch fermentation process.

  12. Cloning, Sequence Analysis, and Expression in Escherichia coli of the Gene Encoding an α-Amino Acid Ester Hydrolase from Acetobacter turbidans

    NARCIS (Netherlands)

    Polderman-Tijmes, Jolanda J.; Jekel, P; de Vries, Erik; van Merode, Annet; Floris, René; Laan, Jan-Metske van der; Sonke, Theo; Janssen, Dick B.

    2002-01-01

    The α-amino acid ester hydrolase from Acetobacter turbidans ATCC 9325 is capable of hydrolyzing and synthesizing β-lactam antibiotics, such as cephalexin and ampicillin. N-terminal amino acid sequencing of the purified α-amino acid ester hydrolase allowed cloning and genetic characterization of the

  13. Cloning, sequence analysis, and expression in Escherichia coli of the gene encoding an alpha-amino acid ester hydrolase from Acetobacter turbidans

    NARCIS (Netherlands)

    Polderman-Tijmes, JJ; Jekel, PA; de Vries, EJ; van Merode, Annet; Floris, R; van der Laan, JM; Sonke, T; Janssen, DB

    2002-01-01

    The alpha-amino acid ester hydrolase from Acetobacter turbidans ATCC 9325 is capable of hydrolyzing and synthesizing beta-lactam antibiotics, such as cephalexin and ampicillin. N-terminal amino acid sequencing of the purified alpha-amino acid ester hydrolase allowed cloning and genetic characterizat

  14. Acetobacter turbidans alpha-amino acid ester hydrolase : merohedral twinning in P2(1) obscured by pseudo-translational NCS

    NARCIS (Netherlands)

    Barends, TRM; Dijkstra, BW; Barends, Thomas R.M.; Dijkstra, Bauke W.

    2003-01-01

    The structure elucidation of the alpha-amino acid ester hydrolase from Acetobacter turbidans by molecular replacement is described. In the monoclinic crystal, the molecules are related by both rotational and pseudo-crystallographic translational NCS (non-crystallographic symmetry). Refinement of the

  15. Determination of dehydrogenase activities involved in D-glucose oxidation in Gluconobacter and Acetobacter strains

    Directory of Open Access Journals (Sweden)

    Florencia Sainz

    2016-08-01

    Full Text Available Acetic acid bacteria (AAB are known for rapid and incomplete oxidation of an extensively variety of alcohols and carbohydrates, resulting in the accumulation of organic acids as the final products. These oxidative fermentations in AAB are catalyzed by PQQ- or FAD- dependent membrane bound dehydrogenases. In the present study, the enzyme activity of the membrane bound dehydrogenases (membrane-bound PQQ-glucose dehydrogenase (mGDH, D-gluconate dehydrogenase (GADH and membrane-bound glycerol dehydrogenase (GLDH involved in the oxidation of D-glucose and D-gluconic acid (GA was determined in six strains of three different species of AAB (three natural and three type strains. Moreover, the effect of these activities on the production of related metabolites (GA, 2-keto-D-gluconic acid (2KGA and 5-keto-D-gluconic acid (5KGA was analyzed. The natural strains belonging to Gluconobacter showed a high mGDH activity and low activity in GADH and GLDH, whereas the A. malorum strain presented low activity in the three enzymes. Nevertheless, no correlation was observed between the activity of these enzymes and the concentration of the corresponding metabolites. In fact, all the tested strains were able to oxidize D-glucose to GA, being maximal at the late exponential phase of the AAB growth (24 h, which coincided with glucose exhaustion and the maximum mGDH activity. Instead, only some of the tested strains were capable of producing 2KGA and/or 5KGA. In the case of G. oxydans strains, no 2KGA production was detected which is related to the absence of GADH activity after 24 h, while in the remaining strains, detection of GADH activity after 24h resulted in a high accumulation of 2KGA. Therefore, it is possible to choose the best strain depending on the desired product composition.Moreover, the sequences of these genes were used to construct phylogenetic trees. According to the sequence of gcd, gene coding for mGDH, Acetobacter and Komagataeibacter were

  16. Ocorrência de micorrizas arbusculares e da bactéria diazotrófica Acetobacter diazotrophicus em cana-de-açúcar Occurrence of arbuscular mycorrhizae and bacterium Acetobacter diazotrophicus in sugar cane

    OpenAIRE

    Veronica Massena Reis; Mauro Augusto de Paula; Johanna Döbereiner

    1999-01-01

    Foi avaliada a ocorrência e a distribuição de espécies de fungos micorrízicos arbusculares (FMAs) e Acetobacter diazotrophicus em plantios de cana-de-açúcar em diferentes tipos de manejo nos Estados do Rio de Janeiro e Pernambuco. Foram feitas 35 coletas de amostras de solo da rizosfera e de raízes de 14 variedades de cana-de-açúcar para extração de esporos e isolamento da bactéria. O número de esporos variou de 18 a 2.070/100 mL de solo, e os maiores número e diversidade de espécies foram ve...

  17. Seperation and identification of acetobacter from naturally fermentated apple vinegar%自然发酵的苹果醋中醋酸菌的分离鉴定

    Institute of Scientific and Technical Information of China (English)

    李大为; 朱运平; 张雪; 李秀婷; 梁治军; 孙宝国; 杨然

    2015-01-01

    选用自然发酵的苹果醋醪液为样品,以恶臭醋酸杆菌AS1.41为对照菌株.采用钙平板分离初筛、革兰氏染色与产醋酸定性试验初步鉴定、乙醇氧化试验法复筛等方法从中分离筛选出5株醋酸菌.再经过产酸量试验、耐盐性试验、耐酒精性试验等一系列试验后,确定了2株产酸量高且稳定的优势醋酸菌株,并对其进行形态观察、生理生化试验、16S rDNA序列以及dnaK功能基因序列分析.最终鉴定这2株菌分别为巴氏醋酸杆菌(Acetobacter pasteurianus)B103和热带醋酸杆菌(Acetobacter tropicalis)B104.其中巴氏醋酸杆菌(Acetobacter pasteurianus)B103的产酸量达到35.6g/L,耐酒精浓度为7%,耐盐浓度为0.3%.热带醋酸杆菌(Acetobacter tropicalis)B104的产酸量达到33.2g/L,耐酒精浓度为7%,耐盐浓度为0.3%.

  18. Ocorrência de micorrizas arbusculares e da bactéria diazotrófica Acetobacter diazotrophicus em cana-de-açúcar Occurrence of arbuscular mycorrhizae and bacterium Acetobacter diazotrophicus in sugar cane

    Directory of Open Access Journals (Sweden)

    Veronica Massena Reis

    1999-10-01

    Full Text Available Foi avaliada a ocorrência e a distribuição de espécies de fungos micorrízicos arbusculares (FMAs e Acetobacter diazotrophicus em plantios de cana-de-açúcar em diferentes tipos de manejo nos Estados do Rio de Janeiro e Pernambuco. Foram feitas 35 coletas de amostras de solo da rizosfera e de raízes de 14 variedades de cana-de-açúcar para extração de esporos e isolamento da bactéria. O número de esporos variou de 18 a 2.070/100 mL de solo, e os maiores número e diversidade de espécies foram verificados nos canaviais de Campos, RJ, especialmente naqueles que não adotam a queima do palhiço. As espécies predominantes nas três localidades amostradas foram: Acaulospora sp., Scutellospora heterogama, Glomus etunicatum, Glomus occultum e Gigaspora margarita. A. diazotrophicus estava presente nas amostras de raízes colhidas em canaviais de Campos, com exceção de uma coleta de cana-de-açúcar plantada num solo usado como bacia de sedimentação de vinhaça. Não foi possível isolar essa bactéria a partir de esporos desinfestados dos FMAs nativos, apenas dos esporos lavados com água estéril.The occurrence and distribution of species of arbuscular mycorrhizae fungi and Acetobacter diazotrophicus in sugar cane (Saccharum officinarum grown in different regimes of crop management in the States of Rio de Janeiro and Pernambuco, Brazil, were studied. Thirty five samples of the rhizosphere soil and roots were collected from 14 varieties of sugar cane for the extraction of spores and isolation of the bacterium. The number of spores varied from 18 to 2,070 per 100 mL of soil, and the greatest diversity of fungal species was found in the sugarcane fields of Campos (Rio de Janeiro State, especially in those where the sugarcane trash was not burned at harvest. The predominant species found in the three localities sampled were: Scutellospora heterogama, Glomus etunicatum, Glomus occultum, Acaulospora sp. and Gigaspora margarita. A

  19. Acetobacter xylinum CGMCC5173发酵生产细菌纤维素的条件优化%Optimization of the Production of Bacterial Cellulose Fermented by Acetobacter Xylinum CGMCC5173

    Institute of Scientific and Technical Information of China (English)

    许燕娜; 张剑恩; 黎嘉惠; 蔡兴蓉; 黄娆勤; 吴晖; 刘冬梅

    2012-01-01

    为提高Acetobacter xylinum CGMCC5173生产细菌纤维素(BC)的产量,对该菌生产BC的条件进行优化.研究表明,采用CJMF培养基,培养到第二代时BC产量最高,达到43.91 g/L;采用HMF培养基,当接种量为10%,蔗糖、乙酸钠、乙醇和L-乳酸的含量分别为10%、1.0%、1.5%和0.25%时,细菌纤维素产量最高,分别达到14.79 g/L、7.47 g/L、4.24 g/L、40.07 g/L和21.92g/L;而D-乳酸越多,BC产量越低;采用80% HMF与20% CJMF混合复配的发酵液,BC的产量最高为29.30 g/L.结果表明,控制A.xylinum 5173的培养代数和用HMF与CJMF复配的发酵液可稳定和有效地提高BC产量.%In order to improve the yield of Bacterial Cellulose fermented by Acetobacter xylinum CGMCC5173, the optimum conditions for fermentation were investigated. The result showed that, in CJMF medium, BC production reached the highest as 43.91 g/L when ^4. xylinum 5173 was cultivated to the second generation. In HMF medium, when the quantity of inoculums content, sucrose, sodium acetate, ethanol and L-lactic acid are 10%, 10%, 1.0%, 1.5% and 0.25% respectively, BC production were enhanced up to their peak, as 14.79 g/L, 7.47 g/L, 4.24g/L, 40.07 g/L and 21.92 g/L. However.the higher the D-lactic content was, the less the BC content was found. When the medium was mixed 20% CJMF with 80 % HMF, the BC yield was highest as 29.30 g/L. The results indicated that controlling cultivation generation and using mixed medium of HMF and CJMF can improve the BC yield steadily and effectively.

  20. Optimum Culture Conditions for Bacterial Cellulose Produced by Acetobacter xylinum NUST4%Acetobacter xylinum NUST4合成细菌纤维素发酵条件的优化

    Institute of Scientific and Technical Information of China (English)

    周伶俐; 孙东平; 吴清杭; 杨树林

    2005-01-01

    采用均匀设计法优化了Acetobacter xylinum NUST4的基础培养基,向其中添加了Mg2+、Fe2+、对氨基苯甲酸、烟酸、生物素、乙醇,优化后的发酵培养基组成为:葡萄糖24g,蔗糖22g,蛋白胨16g,醋酸2.4mL,磷酸氢二钠3.5g,磷酸二氢钾1g,硫酸镁6g,硫酸亚铁0.015g,烟酸0.003g,生物素0.02g和乙醇20mL,纤维素产量达9.87g,定容至1L,比由S-H培养基发酵合成的纤维素产量(仅0.74g·L-1)提高了12倍.

  1. Purification of Alcohol Dehydrogenase from Acetobacter Z127 and Parts of Its nzymatic property%Acetobacter Z127乙醇脱氢酶的纯化及酶学性质

    Institute of Scientific and Technical Information of China (English)

    霍丹群; 张云茹; 侯长军

    2006-01-01

    利用自行筛选、鉴定的Acetobacter Z127,纯化出高活性的乙醇脱氢酶,并对该酶的生化特性进行了初步研究.试验表明:粗酶液通过硫酸铵分级沉淀、透析脱盐、Sephadex G-100层析分离,纯化出一种以NAD+为辅酶的ADH,经SDS-PAGE电泳检测其分子量为28KDa;ADH反应的最适pH值为7.0,最适温度为60℃,K+离子对其酶活有促进作用,二价金属离子对其活性有抑制作用,Fe3+极易使ADH产生沉淀.研究为ADH的应用及其新用途的探索提供了理论基础和可靠的工艺参数.

  2. Global insights into acetic acid resistance mechanisms and genetic stability of Acetobacter pasteurianus strains by comparative genomics.

    Science.gov (United States)

    Wang, Bin; Shao, Yanchun; Chen, Tao; Chen, Wanping; Chen, Fusheng

    2015-12-22

    Acetobacter pasteurianus (Ap) CICC 20001 and CGMCC 1.41 are two acetic acid bacteria strains that, because of their strong abilities to produce and tolerate high concentrations of acetic acid, have been widely used to brew vinegar in China. To globally understand the fermentation characteristics, acid-tolerant mechanisms and genetic stabilities, their genomes were sequenced. Genomic comparisons with 9 other sequenced Ap strains revealed that their chromosomes were evolutionarily conserved, whereas the plasmids were unique compared with other Ap strains. Analysis of the acid-tolerant metabolic pathway at the genomic level indicated that the metabolism of some amino acids and the known mechanisms of acetic acid tolerance, might collaboratively contribute to acetic acid resistance in Ap strains. The balance of instability factors and stability factors in the genomes of Ap CICC 20001 and CGMCC 1.41 strains might be the basis for their genetic stability, consistent with their stable industrial performances. These observations provide important insights into the acid resistance mechanism and the genetic stability of Ap strains and lay a foundation for future genetic manipulation and engineering of these two strains.

  3. Efficient Production Process for Food Grade Acetic Acid by Acetobacter aceti in Shake Flask and in Bioreactor Cultures

    Directory of Open Access Journals (Sweden)

    Hassan M. Awad

    2012-01-01

    Full Text Available Acetic acid is one of the important weak acids which had long history in chemical industries. This weak organic acid has been widely used as one of the key intermediate for many chemical, detergent, wood and food industries. The production of this acid is mainly carried out using submerged fermentation system and the standard strain Acetobacter aceti. In the present work, six different media were chosen from the literatures and tested for acetic acid production. The highest acetic acid production was produced in medium composed of glucose, yeast extract and peptone. The composition of this medium was optimized by changing the concentration of medium components. The optimized medium was composed of (g/L: glucose, 100; yeast extract, 12 and peptone 5 and yielded 53 g/L acetic acid in shake flask after 144 h fermentation. Further optimization in the production process was achieved by transferring the process to semi-industrial scale 16-L stirred tank bioreactor and cultivation under controlled pH condition. Under fully aerobic conditions, the production of acetic acid reached maximal concentration of about 76 g/L and 51 g/L for uncontrolled and controlled pH cultures, respectively.

  4. Global insights into acetic acid resistance mechanisms and genetic stability of Acetobacter pasteurianus strains by comparative genomics

    Science.gov (United States)

    Wang, Bin; Shao, Yanchun; Chen, Tao; Chen, Wanping; Chen, Fusheng

    2015-12-01

    Acetobacter pasteurianus (Ap) CICC 20001 and CGMCC 1.41 are two acetic acid bacteria strains that, because of their strong abilities to produce and tolerate high concentrations of acetic acid, have been widely used to brew vinegar in China. To globally understand the fermentation characteristics, acid-tolerant mechanisms and genetic stabilities, their genomes were sequenced. Genomic comparisons with 9 other sequenced Ap strains revealed that their chromosomes were evolutionarily conserved, whereas the plasmids were unique compared with other Ap strains. Analysis of the acid-tolerant metabolic pathway at the genomic level indicated that the metabolism of some amino acids and the known mechanisms of acetic acid tolerance, might collaboratively contribute to acetic acid resistance in Ap strains. The balance of instability factors and stability factors in the genomes of Ap CICC 20001 and CGMCC 1.41 strains might be the basis for their genetic stability, consistent with their stable industrial performances. These observations provide important insights into the acid resistance mechanism and the genetic stability of Ap strains and lay a foundation for future genetic manipulation and engineering of these two strains.

  5. Medium Optimization of Acetobacter xylinum HN001%木醋杆菌的培养基优化研究

    Institute of Scientific and Technical Information of China (English)

    杜晶晶; 曹献英; 林强; 陈胜杰; 胡凌俊

    2011-01-01

    采用六因素三水平正交实验对木醋杆菌Acetobacter xylinum HN001的培养基进行了优化,确定了最佳培养基组成为:葡萄糖30g/L,蛋白胨7.5g/L,酵母粉10g/L,磷酸氢二钠7.5g/L,柠檬酸0.5g/L,pH 5.0,30℃.采用优化的培养基制备细菌纤维素,应用傅立叶红外光谱、热重分析和扫描电子显微镜对其结构和性能进行表征.红外光谱测试显示含有纤维素的特征吸收峰.热重分析结果表明细菌纤维素最大失重温度为319.06℃,热稳定性较好.扫描电镜观察到细菌纤维素的纳米网状结构.

  6. Effect of composites based nickel foam anode in microbial fuel cell using Acetobacter aceti and Gluconobacter roseus as a biocatalysts.

    Science.gov (United States)

    Karthikeyan, Rengasamy; Krishnaraj, Navanietha; Selvam, Ammaiyappan; Wong, Jonathan Woon-Chung; Lee, Patrick K H; Leung, Michael K H; Berchmans, Sheela

    2016-10-01

    This study explores the use of materials such as chitosan (chit), polyaniline (PANI) and titanium carbide (TC) as anode materials for microbial fuel cells. Nickel foam (NF) was used as the base anode substrate. Four different types of anodes (NF, NF/PANI, NF/PANI/TC, NF/PANI/TC/Chit) are thus prepared and used in batch type microbial fuel cells operated with a mixed consortium of Acetobacter aceti and Gluconobacter roseus as the biocatalysts and bad wine as a feedstock. A maximum power density of 18.8Wm(-3) (≈2.3 times higher than NF) was obtained in the case of the anode modified with a composite of PANI/TC/Chit. The MFCs running under a constant external resistance of (50Ω) yielded 14.7% coulombic efficiency with a maximum chemical oxygen demand (COD) removal of 87-93%. The overall results suggest that the catalytic materials embedded in the chitosan matrix show the best performance and have potentials for further development. PMID:26970695

  7. KINETIKA FERMENTASI ASAM ASETAT (VINEGAR OLEH BAKTERI Acetobacter aceti B 127 DARI ETANOL HASIL FERMENTASI LIMBAH CAIR PULP KAKAO [Kinetics of Acetic Acid (Vinegar Fermentation By Acetobacter aceti B127 from Ethanol Produced by Fermentation of Liquid Waste of Cacao Pulp

    Directory of Open Access Journals (Sweden)

    M. Supli Effendi

    2002-08-01

    Full Text Available Acetic acid concentration is one of vinegar’s quality parameter. Acetic acid concentration in vinegar is influenced by the activity of acetic acid bacteria. This research studied the kinetics of anaerobic fermentation of liquid waste of cacao pulp by Saccharomyces cerevisiae R60 to produce ethanol and the kinetics of acetic acid fermentation from ethanol by Acetobacter aceti B127. The kinetics of acetic acid fermentation from ethanol by Acetobacter aceti B127 can be used as a basic of bioprocess design for aerobic fermentation in general and acetic acid fermentation from ethanol by Acetobacter aceti B127 in particular. Fermentation medium used was liquid waste of cocoa pulp with sugar content of 12.85%, and the addition of sucrosa and urea. The parameter observed was growth of Saccharomyces cerevisiae R60 and Acetobacter aceti B127, and chemical analysis including concentration of ethanol, total sugar and acetic acid, content. The research result showed that the  value was 0.048 hour-1, Y P was 0.676, Qp value was 0.033 hour-, and KLa value was 0.344, QO2.Cx value was 0.125 (mgO2L-1jam-1, Y X was s O2 0.378 (x 108selmL-1g-1¬¬O2, and dCT was 0.150 mgL-1hour-1. Concentration of acetic acid in the product was 4.24% or 42.4 gL-1

  8. 醋酸杆菌生物催化丙烯醛合成丙烯酸%Biosynthesis of acrylic acid from acrolein by Acetobacter sp.

    Institute of Scientific and Technical Information of China (English)

    王旭昌; 宗红; 陆信曜; 诸葛斌; 方慧英; 宋健; 诸葛健

    2015-01-01

    丙烯酸是一种重要的有机化工原料,主要用于合成树脂和丙烯酸酯,广泛应用于生产和生活的各方面.本文开展了利用微生物催化丙烯醛生产丙烯酸的研究.通过菌株筛选和ESI-MS验证,获得2株目的微生物,经鉴定比较发现Acetobacter sp.对丙烯醛的催化效率较高,在Acetobacter sp.细胞浓度15 g/L,初始底物浓度10 g/L,pH 6.8,30℃的条件下反应1h,转化率可达88.0%,产物浓度达到11.32 g/L丙烯酸.同时,利用固定化细胞的方法提高反应对底物和产物的耐受性,经过2.5h的反应,20 g/L的丙烯醛被催化成22.96 g/L丙烯酸,摩尔转化率为89.3%,固定化细胞重复利用6次后转化率仍可达到85.4%.利用Acetobacter sp.细胞催化生产丙烯酸,为丙烯酸的制备提供了一种新的可能.

  9. Study on Formula and Process of Fermented Honey drink by Acetobacter Fermentation%蜂蜜醋酸发酵饮料配方及工艺研究

    Institute of Scientific and Technical Information of China (English)

    王树林; 赵永华; 李宗文

    2001-01-01

    Optimal formula and process have been determined through thestudy of relationship among the additive quantities of honey, yeast and acetobacter with different tempertures and times of fermentation to evaluate quality and rate of fermentation.%通过讨论蜂蜜添加量、酵母和醋酸菌接种量、发酵温度及时间对产品感官质量和发酵速度的影响,确定了产品的最佳配方及发酵工艺。

  10. Breeding of Acetobacter xylinum C5 by Ultraviolet Mutagenesis%细菌纤维素高产菌株的紫外诱变育种研究

    Institute of Scientific and Technical Information of China (English)

    赵琼; 杨谦

    2007-01-01

    以木醋杆菌(Acetobacter xylinum)C5为出发菌株,对其进行紫外诱变,将照射时间3 min作为紫外诱变剂量,经过初筛和复筛,获得1株细菌纤维素高产菌株A.xylinumC544,该突变株的产量是原始菌株的1.5倍.

  11. Simultaneous production of acetic and gluconic acids by a thermotolerant Acetobacter strain during acetous fermentation in a bioreactor.

    Science.gov (United States)

    Mounir, Majid; Shafiei, Rasoul; Zarmehrkhorshid, Raziyeh; Hamouda, Allal; Ismaili Alaoui, Mustapha; Thonart, Philippe

    2016-02-01

    The activity of bacterial strains significantly influences the quality and the taste of vinegar. Previous studies of acetic acid bacteria have primarily focused on the ability of bacterial strains to produce high amounts of acetic acid. However, few studies have examined the production of gluconic acid during acetous fermentation at high temperatures. The production of vinegar at high temperatures by two strains of acetic acid bacteria isolated from apple and cactus fruits, namely AF01 and CV01, respectively, was evaluated in this study. The simultaneous production of gluconic and acetic acids was also examined in this study. Biochemical and molecular identification based on a 16s rDNA sequence analysis confirmed that these strains can be classified as Acetobacter pasteurianus. To assess the ability of the isolated strains to grow and produce acetic acid and gluconic acid at high temperatures, a semi-continuous fermentation was performed in a 20-L bioreactor. The two strains abundantly grew at a high temperature (41°C). At the end of the fermentation, the AF01 and CV01 strains yielded acetic acid concentrations of 7.64% (w/v) and 10.08% (w/v), respectively. Interestingly, CV01 was able to simultaneously produce acetic and gluconic acids during acetic fermentation, whereas AF01 mainly produced acetic acid. In addition, CV01 was less sensitive to ethanol depletion during semi-continuous fermentation. Finally, the enzymatic study showed that the two strains exhibited high ADH and ALDH enzyme activity at 38°C compared with the mesophilic reference strain LMG 1632, which was significantly susceptible to thermal inactivation.

  12. In vivo and in vitro evaluation of an Acetobacter xylinum synthesized microbial cellulose membrane intended for guided tissue repair

    Directory of Open Access Journals (Sweden)

    de Lima-Neto João

    2009-03-01

    Full Text Available Abstract Background Barrier materials as cellulose membranes are used for guided tissue repair. However, it is essential that the surrounding tissues accept the device. The present study histologically evaluated tissue reaction to a microbial cellulose membrane after subcutaneous implantation in mice. Furthermore, the interaction between mesenchymal stem cells and the biomaterial was studied in vitro to evaluate its ability to act as cellular scaffold for tissue engineering. Methods Twenty-five Swiss Albino mice were used. A 10 × 10 mm cellulose membrane obtained through biosynthesis using Acetobacter xylinum bacteria was implanted into the lumbar subcutaneous tissue of each mouse. The mice were euthanatized at seven, 15, 30, 60, and 90 days, and the membrane and surrounding tissues were collected and examined by histology. Results A mild inflammatory response without foreign body reaction was observed until 30 days post-surgery around the implanted membrane. Polarized microscopy revealed that the membrane remained intact at all evaluation points. Scanning electron microscopy of the cellulose membrane surface showed absence of pores. The in vitro evaluation of the interaction between cells and biomaterial was performed through viability staining analysis of the cells over the biomaterial, which showed that 95% of the mesenchymal stem cells aggregating to the cellulose membrane were alive and that 5% were necrotic. Scanning electron microscopy showed mesenchymal stem cells with normal morphology and attached to the cellulose membrane surface. Conclusion The microbial cellulose membrane evaluated was found to be nonresorbable, induced a mild inflammatory response and may prove useful as a scaffold for mesenchymal stem cells.

  13. A novel carbonyl reductase with anti-Prelog stereospecificity from Acetobacter sp. CCTCC M209061: purification and characterization.

    Directory of Open Access Journals (Sweden)

    Xiao-Hong Chen

    Full Text Available A novel carbonyl reductase (AcCR catalyzing the asymmetric reduction of ketones to enantiopure alcohols with anti-Prelog stereoselectivity was found in Acetobacter sp. CCTCC M209061 and enriched 27.5-fold with an overall yield of 0.4% by purification. The enzyme showed a homotetrameric structure with an apparent molecular mass of 104 kDa and each subunit of 27 kDa. The gene sequence of AcCR was cloned and sequenced, and a 762 bp gene fragment was obtained. Either NAD(H or NADP(H can be used as coenzyme. For the reduction of 4'-chloroacetophenone, the Km value for NADH was around 25-fold greater than that for NADPH (0.66 mM vs 0.026 mM, showing that AcCR preferred NADPH over NADH. However, when NADH was used as cofactor, the response of AcCR activity to increasing concentration of 4'-chloroacetophenone was clearly sigmoidal with a Hill coefficient of 3.1, suggesting that the enzyme might possess four substrate-binding sites cooperating with each other The Vmax value for NADH-linked reduction was higher than that for NADPH-linked reduction (0.21 mM/min vs 0.17 mM/min. For the oxidation of isopropanol, the similar enzymological properties of AcCR were found using NAD+ or NADP+ as cofactor. Furthermore, a broad range of ketones such as aryl ketones, α-ketoesters and aliphatic ketones could be enantioselectively reduced into the corresponding chiral alcohols by this enzyme with high activity.

  14. A novel carbonyl reductase with anti-Prelog stereospecificity from Acetobacter sp. CCTCC M209061: purification and characterization.

    Science.gov (United States)

    Chen, Xiao-Hong; Wei, Ping; Wang, Xiao-Ting; Zong, Min-Hua; Lou, Wen-Yong

    2014-01-01

    A novel carbonyl reductase (AcCR) catalyzing the asymmetric reduction of ketones to enantiopure alcohols with anti-Prelog stereoselectivity was found in Acetobacter sp. CCTCC M209061 and enriched 27.5-fold with an overall yield of 0.4% by purification. The enzyme showed a homotetrameric structure with an apparent molecular mass of 104 kDa and each subunit of 27 kDa. The gene sequence of AcCR was cloned and sequenced, and a 762 bp gene fragment was obtained. Either NAD(H) or NADP(H) can be used as coenzyme. For the reduction of 4'-chloroacetophenone, the Km value for NADH was around 25-fold greater than that for NADPH (0.66 mM vs 0.026 mM), showing that AcCR preferred NADPH over NADH. However, when NADH was used as cofactor, the response of AcCR activity to increasing concentration of 4'-chloroacetophenone was clearly sigmoidal with a Hill coefficient of 3.1, suggesting that the enzyme might possess four substrate-binding sites cooperating with each other The Vmax value for NADH-linked reduction was higher than that for NADPH-linked reduction (0.21 mM/min vs 0.17 mM/min). For the oxidation of isopropanol, the similar enzymological properties of AcCR were found using NAD+ or NADP+ as cofactor. Furthermore, a broad range of ketones such as aryl ketones, α-ketoesters and aliphatic ketones could be enantioselectively reduced into the corresponding chiral alcohols by this enzyme with high activity. PMID:24740089

  15. Separation of Acetobacter aceti and Compared the Rules of Produced Organic Acid%醋酸菌分离及其有机酸产生规律

    Institute of Scientific and Technical Information of China (English)

    李亚武; 张宝善; 魏冉; 王玮; 黄雯

    2015-01-01

    For compared the rules of different forms of Acetobacter aceti produced organic acid. Determination of organic acids by HPLC method found:S strain had more ability than R strain for produced quinic acid , malic acid, fumaric acid and succinic acid and less ability for produced ability lactic acid and citric acid. Therefore , we can infer that ornithine cycle, gluconeogenesis, and the citric acid cycle involved in the formation of Acetobacter aceti pellice.%研究不同形态醋酸菌产生有机酸规律的比较。经HPLC法测定有机酸含量发现:不产膜菌S菌产生奎宁酸、苹果酸、富马酸和琥珀酸的能力比产膜菌R菌高;而产生乳酸和柠檬酸的能力低于R菌。因此推断鸟氨酸循环、糖异生作用和三羧酸循环参与醋酸菌菌膜的形成。

  16. 细菌纤维素生产过程Acetobacter xylinum NUST4.2的细胞浓度测定方法研究%Concentration determination of Acetobacter xylinum NUST4.2 during production of bacterial cellulose

    Institute of Scientific and Technical Information of China (English)

    殷智超; 周浩; 徐海东; 刘林枝; 刘广梅; 孙东平

    2010-01-01

    讨论了比浊法和MTT比色法2种细胞浓度测定方法在Acetobacter xylinum NUST4.2发酵生产细菌纤维素过程中的应用.结果显示,比浊法可以很好的应用在总菌浓度的测量上,而MMT比色法测游离活菌浓度时较适合,但是仍然会受产物影响不能很好的反映发酵液总的活菌浓度.

  17. Green synthesis of silver and gold nanoparticles employing levan, a biopolymer from Acetobacter xylinum NCIM 2526, as a reducing agent and capping agent.

    Science.gov (United States)

    Ahmed, Khan Behlol Ayaz; Kalla, Divya; Uppuluri, Kiran Babu; Anbazhagan, Veerappan

    2014-11-01

    With a vision of finding greener materials to synthesize nanoparticles, we report the production and isolation of levan, a polysaccharide with repeating units of fructose, from Acetobacter xylinum NCIM2526. The isolated levan were characterized using potassium ferricyanide reducing power assay, Fourier transform infra-red (FTIR) spectroscopy and (1)H nuclear magnetic resonance spectroscopy ((1)H NMR). To exploit levan in nanotechnology, we present a simple and greener method to synthesize silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) using biopolymer, levan as both reducing and stabilizing agents. The morphology and stability of the AgNPs and AuNPs were examined by transmission electron microscopy (TEM) and UV-vis absorption (UV-vis) spectroscopy. The possible capping mechanism of the nanoparticles was postulated using FTIR studies. As synthesized biogenic nanoparticles showed excellent catalytic activity as evidenced from sodium borohydride mediated reduction of 4-nitro phenol and methylene blue. PMID:25129779

  18. Study of the gel films of Acetobacter Xylinum cellulose and its modified samples by 1H NMR cryoporometry and small-angle X-ray scattering

    International Nuclear Information System (INIS)

    Gel films of Acetobacter Xylinum cellulose and its modified samples have been investigated by 1H nuclear magnetic resonance (NMR) cryoporometry and small-angle X-ray scattering. The joint use of these two methods made it possible to characterize the sizes of aqueous pores in gel films and estimate the sizes of structural inhomogeneities before and after the sorption of polyvinylpyrrolidone and Se0 nanoparticles (stabilized by polyvinylpyrrolidone) into the films. According to small-angle X-ray scattering data, the sizes of inhomogeneities in a gel film change only slightly upon the sorption of polyvinylpyrrolidone and nanoparticles. The impregnated material is sorbed into water-filled cavities that are present in the gel film. 1H NMR cryoporometry allowed us to reveal the details of changes in the sizes of small aqueous pores during modifications.

  19. Study of the gel films of Acetobacter Xylinum cellulose and its modified samples by {sup 1}H NMR cryoporometry and small-angle X-ray scattering

    Energy Technology Data Exchange (ETDEWEB)

    Babushkina, T. A.; Klimova, T. P. [Russian Academy of Sciences, Nesmeyanov Institute of Organoelement Compounds (Russian Federation); Shtykova, E. V.; Dembo, K. A.; Volkov, V. V. [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation); Khripunov, A. K. [Russian Academy of Sciences, Institute of Macromolecular Compounds (Russian Federation); Klechkovskaya, V. V., E-mail: klechvv@ns.crys.ras.ru [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation)

    2010-03-15

    Gel films of Acetobacter Xylinum cellulose and its modified samples have been investigated by 1H nuclear magnetic resonance (NMR) cryoporometry and small-angle X-ray scattering. The joint use of these two methods made it possible to characterize the sizes of aqueous pores in gel films and estimate the sizes of structural inhomogeneities before and after the sorption of polyvinylpyrrolidone and Se{sub 0} nanoparticles (stabilized by polyvinylpyrrolidone) into the films. According to small-angle X-ray scattering data, the sizes of inhomogeneities in a gel film change only slightly upon the sorption of polyvinylpyrrolidone and nanoparticles. The impregnated material is sorbed into water-filled cavities that are present in the gel film. {sup 1}H NMR cryoporometry allowed us to reveal the details of changes in the sizes of small aqueous pores during modifications.

  20. Identification of the uridine 5'-diphosphoglucose (UDP-Glc) binding subunit of cellulose synthase in Acetobacter xylinum using the photoaffinity probe 5-azido-UDP-Glc

    Energy Technology Data Exchange (ETDEWEB)

    Lin, F.C.; Brown, R.M. Jr.; Drake, R.R. Jr.; Haley, B.E. (Univ. of Texas, Austin (USA))

    1990-03-25

    Photoaffinity labeling of purified cellulose synthase with (beta-32P)5-azidouridine 5'-diphosphoglucose (UDP-Glc) has been used to identify the UDP-Glc binding subunit of the cellulose synthase from Acetobacter xylinum strain ATCC 53582. The results showed exclusive labeling of an 83-kDa polypeptide. Photoinsertion of (beta-32P)5-azido-UDP-Glc is stimulated by the cellulose synthase activator, bis-(3'----5') cyclic diguanylic acid. Addition of increasing amounts of UDP-Glc prevents photolabeling of the 83-kDa polypeptide. The reversible and photocatalyzed binding of this photoprobe also showed saturation kinetics. These studies demonstrate that the 83-kDa polypeptide is the catalytic subunit of the cellulose synthase in A. xylinum strain ATCC 53582.

  1. Optimization of culture conditions to produce high yields of active Acetobacter sp. CCTCC M209061 cells for anti-Prelog reduction of prochiral ketones

    Directory of Open Access Journals (Sweden)

    Chen Xiao-Hong

    2011-11-01

    Full Text Available Abstract Background Chiral alcohols are widely used in the synthesis of chiral pharmaceuticals, flavors and functional materials and appropriate whole-cell biocatalysts offer a highly enantioselective, minimally polluting route to these valuable compounds. The recently isolated strain Acetobacter sp. CCTCC M209061 showed exclusive anti-Prelog stereoselectivity for the reduction of prochiral ketones, but the low biomass has limited its commercialization and industrial applications. To tackle this problem, the effects of medium components and culture conditions on the strain's growth and reduction activity were explored. Results By using a one-at-a-time method and a central composite rotatable design (CCRD, the optimal medium and culture conditions were found to be as follows: glucose 8.26 g/L, fructose 2.50 g/L, soy peptone 83.92 g/L, MnSO4·H2O 0.088 g/L, pH 5.70, 30°C and 10% (v/v inoculum. Under the above-mentioned conditions, the biomass after 30 h cultivation reached 1.10 ± 0.03 g/L, which was 9.5-fold higher than that obtained with basic medium. Also, the reduction activity towards 4'-chloroacetophenone was markedly enhanced to 39.49 ± 0.96 μmol/min/g from 29.34 ± 0.65 μmol/min/g, with the product e.e. being above 99%. Comparable improvements were also seen with the enantioselective bioreduction of 4-(trimethylsilyl-3-butyn-2-one to the key pharmaceutical precursor (R - 4-(trimethylsilyl-3-butyn-2-ol. Conclusions The biomass and reduction activity of Acetobacter sp. CCTCC M209061 can be greatly enhanced through the optimization strategy. This facilitates use of the strain in the anti-Prelog stereoselective reduction of prochiral ketones to enantiopure chiral alcohols as building blocks for many industries.

  2. 含水有机溶剂体系中固定化Acetobacter sp.CCTCC M209061细胞催化乙酰乙酸乙酯不对称还原反应%Biocatalytic Asymmetric Reduction of Ethyl Acetoacetate with Immobilized Acetobacter sp.CCTCC M209061 Cells in a Micro-water-containing Organic Solvent

    Institute of Scientific and Technical Information of China (English)

    徐玉; 王晓婷; 娄文勇; 宗敏华

    2014-01-01

    本论文报道了含微水有机溶剂体系中固定化Acetobacter sp.CCTCC M209061细胞催化乙酰乙酸乙酯不对称还原为(R)-3-羟基丁酸乙酯.研究表明,Acetobacter sp.CCTCC M209061细胞能遵循反Prelog规则高选择性地催化乙酰乙酸乙酯不对称还原.与单水相反应体系相比,含有机溶剂体系不仅可有效地解决底物和产物的抑制作用,而且可提高反应底物的浓度和产率.在所研究的不同有机溶剂中,正己烷为该反应的最适有机相,其能较好溶解底物且对Acetobacter sp.CCTCC M209061细胞的毒性较小,从而导致反应的初速度较快,产率较高.异丙醇为该反应的最佳辅底物,其最适浓度为60 mmol/L;该反应体系中的最适正己烷体积百分比、反应温度、底物浓度分别为约100.00%(水含量约为0.01 wt%),35℃,40 mmol/L.在此条件下,反应的初速率、产率和产物的e.e.值分别为0.72 μmol/min,85.24%和99.00%以上,明显好于水单相反应体系进行该反应的结果.

  3. 固定化醋酸杆菌发酵条件的研究%Optimization of Fermentation Conditions for Acid Production by Immobilized Acetobacter aceti

    Institute of Scientific and Technical Information of China (English)

    林清华; 唐欣昀

    2011-01-01

    以海藻酸钠为载体,采用包埋法固定化醋酸杆菌,利用固定化醋酸杆菌进行醋酸发酵,寻求其最优工艺参数。在单因素试验的基础上,确定接种量、起始乙醇体积分数和发酵温度为主要影响因素,采用响应面法的Box-Behnken试验设计对发酵条件进行优化。建立产酸量与影响因子的多元二次回归方程,得到固定化醋酸杆菌进行醋酸发酵的最佳条件为:接种量7.88g/100mL,起始乙醇体积分数4.63%,发酵温度32℃,在此条件下,产酸量的理论值为3.56g/100mL。对最佳发酵条件进行实验验证,结果产酸量为3.51g/100mL,%Response surface methodology was employed to find optimal fermentation conditions for immobilized Acetobacter pasteurianus cells obtained by using sodium alginate as the carrier.One-factor-at-a-time experiments were conducted to identify inoculum amount,initial alcohol concentration and temperature as main affecting factors of acid production.On the basis of a three-level,seventeen-run Box-Behnken experimental design,a quadratic regression model equation describing acid production as a function of the three selected variables was established.The results indicated that the optimal conditions for acetic acid fermentation were inoculum amount of 7.88 g/100 mL,initial alcohol concentration of 4.63%,and fermentation temperature of 32 ℃.Under the optimized fermentation conditions,the yield of total acids was 3.51 g/100 mL,which was close to the theoretical yield of 3.56 g/100 mL.Therefore,response surface methodology can provide the optimal fermentation condition of immobilized Acetobacter aceti for practical applications due to its reliability.

  4. 热带醋酸杆菌B104发酵条件的优化研究%Optimization of fermentation conditions of Acetobacter tropicalis B104

    Institute of Scientific and Technical Information of China (English)

    朱运平; 李大为; 张雪; 黄月宜; 李秀婷; 梁治军; 孙宝国

    2015-01-01

    从自然发酵的苹果醋醪中筛选鉴定得到l株热带醋酸杆菌(Acetobacter tropicalis)B 104,为进一步提高这株热带醋酸杆菌的产酸能力,对其培养条件和培养基成分进行了优化.结果表明,最佳培养条件和培养基组成为接种量4.0%,培养温度30℃,摇床转速120 r/min,培养基初始pH值为5.5,10.0g/L葡萄糖和体积分数为5.0%的无水乙醇为碳源,20.0 g/L酵母膏为氮源.在此条件下培养12 d,该菌株产酸量达到55.4 g/L,是优化前的1.5倍.

  5. 木醋杆菌发酵培养基优化及发酵方式的探讨%Medium optimization and fermentation condition of Acetobacter xylinum

    Institute of Scientific and Technical Information of China (English)

    秦微微; 迟玉杰

    2006-01-01

    以木醋杆菌(Acetobacter xylinum)为出发菌株,细菌纤维素产量为指标,通过正交试验优化发酵培养基,其最优组成为葡萄糖15g/L、蛋白胨10 g/L、酵母膏5g/L、玉米浆40mL/L、磷酸三钠3g/L、柠檬酸钠1g/L、硫酸镁2g/L、氯化钙0.2g/L、硫酸亚铁0.03g/L、乙醇10mL/L.适宜的发酵方式为先130r/min振荡培养10h,后静置培养10d.经验证试验,细菌纤维素产量可达3.81 g/L.

  6. Combination of deep eutectic solvent and ionic liquid to improve biocatalytic reduction of 2-octanone with Acetobacter pasteurianus GIM1.158 cell.

    Science.gov (United States)

    Xu, Pei; Du, Peng-Xuan; Zong, Min-Hua; Li, Ning; Lou, Wen-Yong

    2016-01-01

    The efficient anti-Prelog asymmetric reduction of 2-octanone with Acetobacter pasteurianus GIM1.158 cells was successfully performed in a biphasic system consisting of deep eutectic solvent (DES) and water-immiscible ionic liquid (IL). Various DESs exerted different effects on the synthesis of (R)-2-octanol. Choline chloride/ethylene glycol (ChCl/EG) exhibited good biocompatibility and could moderately increase the cell membrane permeability thus leading to the better results. Adding ChCl/EG increased the optimal substrate concentration from 40 mM to 60 mM and the product e.e. kept above 99.9%. To further improve the reaction efficiency, water-immiscible ILs were introduced to the reaction system and an enhanced substrate concentration (1.5 M) was observed with C4MIM·PF6. Additionally, the cells manifested good operational stability in the reaction system. Thus, the efficient biocatalytic process with ChCl/EG and C4MIM·PF6 was promising for efficient synthesis of (R)-2-octanol.

  7. Combination of deep eutectic solvent and ionic liquid to improve biocatalytic reduction of 2-octanone with Acetobacter pasteurianus GIM1.158 cell.

    Science.gov (United States)

    Xu, Pei; Du, Peng-Xuan; Zong, Min-Hua; Li, Ning; Lou, Wen-Yong

    2016-01-01

    The efficient anti-Prelog asymmetric reduction of 2-octanone with Acetobacter pasteurianus GIM1.158 cells was successfully performed in a biphasic system consisting of deep eutectic solvent (DES) and water-immiscible ionic liquid (IL). Various DESs exerted different effects on the synthesis of (R)-2-octanol. Choline chloride/ethylene glycol (ChCl/EG) exhibited good biocompatibility and could moderately increase the cell membrane permeability thus leading to the better results. Adding ChCl/EG increased the optimal substrate concentration from 40 mM to 60 mM and the product e.e. kept above 99.9%. To further improve the reaction efficiency, water-immiscible ILs were introduced to the reaction system and an enhanced substrate concentration (1.5 M) was observed with C4MIM·PF6. Additionally, the cells manifested good operational stability in the reaction system. Thus, the efficient biocatalytic process with ChCl/EG and C4MIM·PF6 was promising for efficient synthesis of (R)-2-octanol. PMID:27185089

  8. Hanseniaspora opuntiae, Saccharomyces cerevisiae, Lactobacillus fermentum, and Acetobacter pasteurianus predominate during well-performed Malaysian cocoa bean box fermentations, underlining the importance of these microbial species for a successful cocoa bean fermentation process.

    Science.gov (United States)

    Papalexandratou, Zoi; Lefeber, Timothy; Bahrim, Bakhtiar; Lee, Ong Seng; Daniel, Heide-Marie; De Vuyst, Luc

    2013-09-01

    Two spontaneous Malaysian cocoa bean box fermentations (one farm, two plantation plots) were investigated. Physical parameters, microbial community dynamics, yeast and bacterial species diversity [mainly lactic acid bacteria (LAB) and acetic acid bacteria (AAB)], and metabolite kinetics were monitored, and chocolates were produced from the respective fermented dry cocoa beans. Similar microbial growth and metabolite profiles were obtained for the two fermentations. Low concentrations of citric acid were found in the fresh pulp, revealing low acidity of the raw material. The main end-products of the catabolism of the pulp substrates glucose, fructose, and citric acid by yeasts, LAB, and AAB were ethanol, lactic acid, acetic acid, and/or mannitol. Hanseniaspora opuntiae, Lactobacillus fermentum, and Acetobacter pasteurianus were the prevalent species of the two fermentations. Saccharomyces cerevisiae, Lactobacillus plantarum, Lactobacillus pentosus, and Acetobacter ghanensis were also found during the mid-phase of the fermentation processes. Leuconostoc pseudomesenteroides and Acetobacter senegalensis were among the prevailing species during the initial phase of the fermentations. Tatumella saanichensis and Enterobacter sp. were present in the beginning of the fermentations and they could be responsible for the degradation of citric acid and/or the production of gluconic acid and lactic acid, respectively. The presence of facultative heterofermentative LAB during the fermentations caused a high production of lactic acid. Finally, as these fermentations were carried out with high-quality raw material and were characterised by a restricted microbial species diversity, resulting in successfully fermented dry cocoa beans and good chocolates produced thereof, it is likely that the prevailing species H. opuntiae, S. cerevisiae, Lb. fermentum, and A. pasteurianus were responsible for it.

  9. Cloning and expression of α-acetolactate decarboxylase gene from Acetobacter racens%醋酸杆菌α-乙酰乳酸脱羧酶基因的克隆表达

    Institute of Scientific and Technical Information of China (English)

    王爱娥; 荫俊; 宋伟; 王慧; 姜永强; 王景林

    2001-01-01

    根据已知α-乙酰乳酸脱羧酶(α-ALDC)的基因序列,用PCR法从醋酸杆菌(Acetobacter racens)中克隆到约1 kb的DNA片段,经DNA测序证明是ALDC基因,将该基因重组到质粒pBV220中,转化大肠杆菌,实现了高表达,获得了目的蛋白表达量约40%的转化子,为下一步研究其酶活性奠定了基础.

  10. BIOLOGICAL AND PHYSICOCHEMICAL PROPERTIES AND COMMERCIAL APPLICATION OF BACTERIAL CELLULOSE PRODUCED BY Acetobacter xylinum (REVIEW)%细菌纤维素生物理化特性和商业用途(综述)

    Institute of Scientific and Technical Information of China (English)

    马承铸; 顾真荣

    2001-01-01

    简要介绍了木醋杆菌(Acetobacter xylinum)纤维素的生物合成、理化特性、发酵和应用研究的进展近况.醋菌纤维素形成纳米级极细的纤维,具有极高的杨氏模量和机械强度、高纯度和高结晶度、高亲水性和生物可降解性,预计不久将成为一种多用途的重要商品生物材料.

  11. Molecular cloning and characterization of two inducible NAD⁺-adh genes encoding NAD⁺-dependent alcohol dehydrogenases from Acetobacter pasteurianus SKU1108.

    Science.gov (United States)

    Masud, Uraiwan; Matsushita, Kazunobu; Theeragool, Gunjana

    2011-11-01

    The cytosolic NAD⁺-dependent alcohol dehydrogenases (NAD⁺-ADHs) are induced in the quinoprotein ADH-(PQQ-ADH) defective Acetobacter pasteurianus SKU1108 mutant during growth in an ethanol medium. The adhI and adhII genes, which encode NAD⁺-ADH I and ADH II, respectively, of this strain have been cloned and characterized. Sequence analyses have revealed that the adhI gene consists of 1029 bp coding for 342 amino acids, which share 99.71% identity with the same protein from A. pasteurianus IFO 3283. Conversely, the adhII gene is composed of 762 bp encoding for a polypeptide of 253 amino acids, which exhibit 99.60% identity with the A. pasteurianus IFO 3283 protein. ADH I is a member of the group I Zn-dependent long-chain ADHs, while the ADH II belongs to the group II short-chain dehydrogenase/reductase NAD⁺-ADHs. The NAD⁺-adh gene disruptants exhibited a growth reduction when grown in an ethanol medium. In Escherichia coli, ethanol induced adhI and adhII promoter activities by approximately 1.5 and 2.0 times, respectively, and the promoter activity of the adhII gene exceeded that of the adhI gene by approximately 3.5 times. The possible promoter regions of the adhI and adhII genes are located at approximately 81-105 bp and 74-92 bp, respectively, from their respective ATG start codons. Their repressor regions might be located in proximity to these promoters and may repress gene expression in the wild-type, where the membrane-bound ADH effectively functions.

  12. A kinetic study of the oxidation by molecular oxygen of the cytochrome chain of intact yeast cells, Acetobacter suboxydans cells, and of particulate suspensions of heart muscle.

    Science.gov (United States)

    Ludwig, G D; Kuby, S A; Edelman, G M; Chance, B

    1983-01-01

    The pre-steady state kinetics of the cytochrome c oxidase reaction with oxygen were studied by a variation in the reaction time between approximately 6 and 25 ms at oxygen concentrations less than 6 mumol/l. For baker's yeast, a pseudo-first-order velocity constant of approximately 150 s-1 at 1.3 mumol/l O2 was obtained corresponding to a second-order reaction between O2 and a3 at a forward velocity constant (k+1) of approximately 3 X 10(7) liter equiv.-1s-1. Thus, the membrane-bound oxidase in the intact cell exhibits one of the most rapid enzyme-substrate reactions to be reported. The value is identical with that of Greenwood and Gibson on an isolated, solubilized cytochrome c oxidase. Similar values of k+1 are calculated from the turnover numbers [k+2 (a+2)] divided by the Km values (formula; see text) measured for these yeast preparations, which points to an almost negligible reverse reaction (k-1) compared to k+2(a+2). Similar calculations for the membrane-bound cytochrome c oxidase of heart muscle give a value of k+1 approximately equal to 10(7) liter equiv.-1s-1. The concordance of the different values of k+1 supports the view that the yeast cell wall does not impart a significant diffusion barrier to the transport of molecular oxygen. In contrast, Acetobacter suboxydans exhibits a much larger value for Km, and has a terminal oxidase of different kinetic parameters.

  13. The mechanism of Acetobacter xylinum cellulose biosynthesis: direction of chain elongation and the role of lipid pyrophosphate intermediates in the cell membrane

    Energy Technology Data Exchange (ETDEWEB)

    Han, N.S.; Robyt, J.F. [Laboratory of Carbohydrate Chemistry and Enzymology, Iowa State University, Ames, IA (United States)

    1998-12-01

    The biosynthesis of Acetobacter xylinum ATCC 10821 cellulose has been studied with resting cells and a membrane preparation using {sup 14}C-pulse and chase reactions, with d-glucose and UDPGlc, respectively. Cellulose was biosynthesized from UDPGlc, and it was found to be tightly associated with both the cells and the membrane. The cellulose chains could be released from the cells and the membrane preparation by treating at pH 2, 100 C for 20 min. The cellulose chains that were released from the pulse and pulse-chase reactions were purified and separated from any low molecular weight substances by gel chromatography on Bio-Gel P4. They were then reduced with sodium borohydride and hydrolyzed with 4 M trifluoroacetic acid at 121 C for 2 h. Labeled products from the acid hydrolyzates were separated by paper chromatography and found to be d-glucose and d-glucitol. The amount of radioactivity in the products was determined by liquid scintillation counting. It was found that the pulsed products from the resting cells gave a ratio of d-[{sup 14}C]glucitol to d-[{sup 14}C]glucose of 1:11, and after chasing, the ratio decreased to 1:36. The pulsed products from the membrane gave a ratio of d-[{sup 14}C]glucitol to d-[{sup 14}C]glucose of 1:12, and after chasing for 5 min the ratio decreased to 1:43, and after 10 min, the ratio decreased to 1:66. These results show that the labeled d-glucitol obtained from the reducing end of the cellulose chain is chased into the interior of the cellulose chain during synthesis, showing that the cellulose chain is elongated from the reducing end. An insertion mechanism for the synthesis of cellulose from UDPGlc is proposed that involves lipid pyrophosphate glycosyl intermediates and three membrane enzymes: lipid phosphate:UDPGlc phosphotransferase, cellulose synthase, and lipid pyrophosphate phosphohydrolase. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  14. Estudo experimental da resposta tecidual à presença de celulose produzida por Acetobacter xylinum no dorso nasal de coelhos Experimental study of the tissue reaction caused by the presence of cellulose produced by Acetobacter Xylinum in the nasal dorsum of rabbits

    Directory of Open Access Journals (Sweden)

    Wander Lopes Amorim

    2009-04-01

    Full Text Available Vários materiais são propostos para reconstrução nasal, não havendo consenso sobre qual o melhor. A manta de celulose produzida por bactéria pode ser mais um elemento para adição cartilaginosa. Não há estudos deste material no dorso nasal. OBJETIVO: Avaliar a resposta tecidual à presença da celulose bacteriana no dorso nasal de coelhos. MATERIAL E MÉTODO: Foram utilizados 22 coelhos Nova Zelândia, sendo que em 20 deles foi implantada a manta de celulose no dorso nasal e em 2 controles nada foi feito. Foram acompanhados por um período de três e seis meses, sendo então retirados as regiões do dorso nasal e narinas dos coelhos e realizado estudo histopatológico levando em consideração parâmetros definidos de condição inflamatória como congestão vascular, intensidade do processo inflamatório e presença de exsudato purulento. RESULTADOS: O processo inflamatório manteve-se estável, demonstrando sua relação com o procedimento cirúrgico, e não com a presença da manta de celulose. Nos demais parâmetros estudados não houve diferença estatisticamente significante. CONCLUSÃO: A manta de celulose de Acetobacter xylinum mostrou boa biocompatibilidade e manteve-se estável no decorrer do tempo de estudo, podendo ser considerada um bom material para uso na elevação do dorso nasal.Several materials have been proposed for nasal reconstruction. There is no consensus on which is the best. The cellulose blanket produced by bacteria may be a possible cartilaginous addition element to the nose. AIM: to study tissue reaction to cellulose in the dorsal nose of rabbits. MATERIALS AND METHODS: 22 New Zealand rabbits were used. In 20 a cellulose blanket was implanted in the nasal dorsum and 2 served as controls. They were followed up through a period of three and six months, after which their nostrils and nasal dorsums were removed and histological studies were carried out on them, considering defined parameters of inflammation such

  15. 水相体系中固定化Acetobacter sp.CCTCC M209061细胞催化(S)-3-氯苯丙醇不对称合成%Asymmetric Synthesis of (S)-3-Chloro-1-phenylpropanol with Immobilized Acetobacter sp.CCTCC M209061 Cells in a Monophasic System

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    黄宇美; 徐玉; 赵冰怡; 娄文勇

    2015-01-01

    光学纯的3-氯苯丙醇是合成抗抑郁类药物的重要中间体.本论文报道了水相体系中固定化Acetobacter sp.CCTCC M209061细胞高效、高选择性地催化3-氯苯丙酮不对称还原为(S)-3-氯苯丙醇,采用聚乙烯醇与海藻酸钠的混合载体对醋酸杆菌细胞进行固定化,所得的固定化细胞的稳定性(热稳定性、pH稳定性及操作稳定性)均明显优于游离细胞.同时,固定化后的微生物细胞具有较好的重复利用性,连续反应3个批次后固定化细胞仍保留了80.0%以上的活性,而游离细胞的相对活性则小于20%.在所研究的体系中,葡萄糖为该反应的最佳辅底物,其最适浓度为50.0 mmol/L;该反应体系中的最适缓冲液pH值、反应温度、底物浓度分别为5.5、30℃和3.0 mmol/L.在此条件下,反应的初速度、产率以及产物的e.e.值依次为1.77 mM/h,88.9%和99.0%以上.

  16. Study on the Fermentation Conditions of Acetobacter sp.to Produce Alcohol Dehydrogenase%醋酸杆菌产乙醇脱氢酶发酵条件的研究

    Institute of Scientific and Technical Information of China (English)

    肖仔君; 黄国清; 莫小婵

    2010-01-01

    选择一株醋酸杆茵Acetobacter sp.CCTCC M209061,通过单因素和正交实验确定醋酸杆菌产乙醇脱氢酶(Alcohol Dehydrogenase,ADH)的最优发酵条件.结果表明,产ADH的最优培养条件为温度30℃、pH值6.0、通气量为100 mL/250 mL、接种量为8%,在此条件下发酵培养24 h,发酵液酶活可达0.340 U/mL.

  17. 有机酸对木醋杆菌合成细菌纤维素的影响规律%Effect of Organic Acid on the Production of Acetobacter xylinum Cellulose

    Institute of Scientific and Technical Information of China (English)

    马霞; 贾士儒; 关凤梅; 王瑞明

    2003-01-01

    木醋杆菌(Acetobacter xylinum)在静止培养条件下,在基本培养基中添加醋酸、柠檬酸和乳酸,可以提高细菌纤维素的产量.但各种增效因子的添加量均有一最适宜的浓度.其中,添加0.1%的醋酸,细菌纤维素的产量为2.75 g/L;加入0.2%的柠檬酸时细菌纤维素产量为2.15 g/L;加入0.1%的乳酸,细菌纤维素的产量为2.76 g/L.

  18. ANALYSIS OF ITS SEQUENCE IN ACETOBACTER XYLINUM AND RESEARCH THE CONDITION OF PRODUCTION FIBRE%木醋杆菌ITS序列分析及产纤维素条件的研究

    Institute of Scientific and Technical Information of China (English)

    张艳玲; 石晓珍; 黄俊生

    2009-01-01

    木醋杆菌(Acetobacter xylinum)是合成纤维素能力最强的细菌,设计木醋杆菌16S-23S rDNA转录间隔区(internally transcribed spacer ITS)序列引物,对其扩增.在GenBank上的登陆号为GenBank EU196159.选择到合适的木醋杆菌ITS扩增引物,PCR扩增条件.木醋杆菌最佳培养温度28℃,通过测定纤维素产量发现最佳接种量5%,最佳碳源为葡萄糖,最佳碳源浓度为2.5%.

  19. SCREENING, IDENTIFICATION AND PRODUCTS TESTING OF HIGH-YIELD CELLULOSE-PRODUCING STRAINS OF Acetobacter xylinum%醋菌纤维素高产菌株筛选和菌物鉴定

    Institute of Scientific and Technical Information of China (English)

    马承铸; 顾真荣

    2000-01-01

    从150份自然材料中分离得到26个产纤维素菌株.其中,Ax-1、Ac- Ⅱ两高产菌株初步鉴定为巴氏醋杆菌木醋亚种(Acetobacter pasteutinus Subsp. Xylinum)和汉森醋杆菌(A. Hansenii).该二菌株在28℃ 4~5d静态培养中,从50g/L蔗糖(或葡萄糖)培养液中产出14g/L或16g/L纤维素,并初步测试了该纤维素的基本特性.

  20. 不同供氧方式对木醋杆菌培养中生物量的影响%Effects of Different Oxygen-supply Modes on Biomass of Acetobacter xylinum

    Institute of Scientific and Technical Information of China (English)

    向东; 王锡彬; 钟春燕

    2011-01-01

    Acetobacter xylinum strain named HN001 was cultivated in the 10 liter fermentation tank by different ways including stationary culture mode, bottom oxygen-supply mode, rhythmic oxygen-supply mode, and modified system of oxygen-supply mode. The results showed that different dissolved oxygen (DO) values in the fermentation liquid were obtained with different oxygen-supply modes but the biomass of HN001 strain showed no increase with increasing DO value. The maximal value of DO was obtained by the bottom oxygen-supply mode which leading to sharp stirs and shear force in the fermentation tank. However, the minimal biomass was achieved because the Acetobacter xylinum strain was liable to negative mutation in this oxygen-supply mode. A silicon tube circling from bottom to top of the tank was used to supply oxygen which formed the modified system of oxygen-supply and gained weak stirs and shear force and the biomass of Acetobacter xylinum strain reached to 14.80X104 viable counts/ml after a 7-day cultivation. The results showed that the modified system of oxygen-supply mode was the best culture mode and the biomass of strain increased nearly 10 times than stationary culture mode.%分别采用静置、底部供氧、间歇式供氧、改进供氧系统等4种培养方式,用10 L发酵罐培养木醋杆菌菌株HN001,研究供氧方式对木醋杆菌生物量的影响.结果表明,通过发酵罐培养木醋杆菌,生物量的变化并未随溶氧量增大而增大.不同供氧方式发酵液中的溶氧量不同,底部供氧方式溶氧量最大,但这种培养方式形成了较大的搅拌和剪切力,生产菌株容易产生负突变,木醋杆菌生物量最小;改进供氧系统培养方式通过发酵罐底部盘旋至顶部的硅胶管供氧,对培养液的搅拌和剪切力较小,培养7 d后,木醋杆菌生物量可达14.80× 104 cfu/mL.比生产中常用的静置培养方式增加了近10倍,同时也优于底部供氧、间歇式供氧培养方式.

  1. 胶醋杆菌生产纤维素凝胶的工业化培养基的优化研究%Study on the Optimization of the Industrial Culture Medium of Acetobacter Xylinum in the Cellulose Producing

    Institute of Scientific and Technical Information of China (English)

    吴周新; 王锡彬; 林强; 陈航

    2003-01-01

    本文研究了胶醋杆菌(Acetobacter xylinum)工业化生产培养基的优化组成.结果表明,影响纤维素凝胶产量的因素依次为:椰子水>醋酸钠>硫酸铵>蔗糖>磷酸二氢钾.影响凝胶中纤维素含量的因素依次为:椰子水>醋酸钠>蔗糖>磷酸二氢钾、硫酸铵.最适pH为4.2,最佳培养温度30℃.综合考虑凝胶产量和凝胶纤维素含量对产品质量的影响,确定培养基的最佳组成为:椰子水40%~50%,蔗糖4%,硫酸铵0.5%,醋酸钠0.2%,磷酸二氢钾0.05%,pH4.2.

  2. The production of acetic acid by Acetobacter pasteurianus with enhanced expression of alchol dehydrogenase%乙醇脱氢酶过表达对醋酸菌发酵产酸影响研究

    Institute of Scientific and Technical Information of China (English)

    宋山; 潘丽军; 吴学凤

    2016-01-01

    目的:通过构建乙醇脱氢酶过表达基因工程菌株提高醋酸菌醋酸发酵产率.方法:PCR扩增沪酿1.01 Acetobacter pasteurianus CICC20001的乙醇脱氢酶亚基Ⅰ(Alcohol dehydrogenase Ⅰ,adhA)和乙醇脱氢酶亚基Ⅱ(Cytochrome c subunit,adhB)基因,将其依次连接到质粒pBBR1MCS-4中,构建重组质粒pBBR-adhA-adhB,并将该重组质粒导入沪酿1.01,成功获得过表达乙醇脱氢酶的基因工程菌,并对基因工程菌与原始菌的微观形态以及发酵特性进行对比分析.结果:乙醇脱氢酶过表达基因工程菌的醋酸发酵产率和酒精耐受性都有所提高.结论:乙醇脱氢酶的过表达不仅提高了醋酸菌的产酸率,其酒精耐受性也有显著提高.

  3. Study on optimized culture conditions and medium composition of Acetobacter pasteurianus B103%巴氏醋酸杆菌B103培养条件和培养基成分的优化研究

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    朱运平; 李大为; 张雪; 李秀婷; 梁治军; 孙宝国; 杨然

    2015-01-01

    本研究以巴氏醋酸杆菌(Acetobacter pasteurianus)B103为出发菌株,以发酵液中醋酸含量为评价指标,对其培养条件和培养基成分进行优化.结果表明最佳培养条件和培养基组成为:按体积百分比接种量为5.0% (v/v),培养温度30℃,摇床转速140r/min,培养基初始pH5.5,1.0%葡萄糖和3.0%无水乙醇为碳源,2.0%酵母膏为氮源,在此条件下醋酸产量可达58.6g/L,是优化前的1.6倍.

  4. 木醋杆菌纤维素合成操纵子的克隆及棉花转化%Cloning Whole Cellulose-Synthesizing Operon (ayacs Operon) from Acetobacter xylinum and Transforming It into Cultivated Cotton Plants

    Institute of Scientific and Technical Information of China (English)

    卢迎春; 魏刚; 朱玉贤

    2002-01-01

    The gram-negative bacterium Acetobacter xylinum synthesizes an extracellular ribbon of cellulose microfibrils that possess unique structural and mechanical properties when compared to higher plant cellulose. All four genes in the cellulose-synthesizing operon (ayacs operon) of A. xylinum Ay201 were amplified by polymerase chain reaction (PCR) using oligonucleotide primers designed according to published acs operon sequence of A. xylinum ATCC 53582. Alignment of the two operons showed that they were highly homologous (98% similarity, 97% identity). AcsA and acsB gene were cloned in pCAMBIA 1301 vector while acsC and acsD were cloned in pCOB302-3 under the control of CaM 35S promoter. The constructs were introduced into cotton by the pollen-tube-pathway method and seeds obtained from putative transgenic plants were germinated on media containing hygromycin and phosphinothricin (PPT). Five seedlings out of 934 seeds were proved to contain all four foreign genes by PCR amplification. This is the first time that a whole operon encoding four different bacterial enzymes with various biological functions is transformed into cultivated cotton plants.%革兰氏阴性菌木醋杆菌(Acetobacter xylinum (Brown) Yamada)合成一种由纤维素微纤丝组成的胞外带状物.与高等植物纤维素相比,它具有独特的结构和机械性能.根据从木醋杆菌ATCC 53582克隆的acs纤维素合成操纵子序列设计引物, 用PCR的方法从木醋杆菌Ay201中克隆了ayacs纤维素合成操纵子的全部4个基因.序列比较发现,两者高度同源.将连上CaMV 35S启动子的acsA、acsB克隆到植物表达载体pCAMBIA 1301上,acsC、acsD克隆到pCOB302-3中.然后通过花粉管通道法转化棉花(Gossypium hirsutum)胚珠,收获的种子在含有卡那霉素和除草剂的双抗培养基上进行筛选.PCR检测发现934粒种子中有5棵植株含有全部4个基因.这是首次将编码4个功能蛋白的细菌操纵子成功地转入棉花.

  5. UV-mutagenesis of Acetobacter xylinum and Screening Good Mutant Strains%紫外线诱变木醋杆菌及优良突变菌种的选育

    Institute of Scientific and Technical Information of China (English)

    蔡兴蓉; 刘冬梅; 许燕娜; 肖性龙; 袁琨

    2013-01-01

    为了提高细菌纤维素(简称BC)量和续代发酵的稳定性,该研究利用紫外线照射木醋杆菌Acetobacter xylinum CGMCC 5173菌株诱变,还对3种不同培养基培养得到BC进行了对比.研究表明,紫外线分别照射3 min、4 min和5 min,经筛选得到UV31、UV32、UV33、UV42、UV44五株产量较高的突变菌株,其产量高达26.96 g/L~35.48 g/L;菌株UV31、UV32、UV33、UV42连续发酵四代产量仍比较稳定,分别稳定在23 g/L~39 g/L、25 g/L~36 g/L、24 g/L~39 g/L;菌株UV32、UV42和野生菌在CMMF中的BC产量高约为19.94 g/L~39.97 g/L,但结构松散,在MMF中BC的产量低为10.17 g/L~22.28 g/L,均匀紧密,在CO-MMF-CMMF中BC产量中等为16.24 g/L~31.09 g/L,较均匀紧密.结果表明,紫外诱变3 min菌株的BC产量高且3代~4代发酵产量保持稳定,CO-MMF-CMMF是最适于发酵的培养基.

  6. Isolation and Identification of An Excellent Strain of Acetobacter spp. for the Fermentation of Changshanhuyou Tangelo Vinegar%胡柚果醋生产菌种的筛选与鉴定

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    刘欠欠; 杨颖; 陆胜民; 陶宁萍; 夏其乐; 邢建荣

    2010-01-01

    目的:筛选1株适合胡柚果醋生产的醋酸菌.方法:从自然发酵胡柚果醋中筛选产醋酸菌种,研究其酒精耐受性、酒精消耗速度、产醋酸速度;分别发酵生产胡柚果醋,对其进行感官分析,以Vitek-32型微生物分析系统对最适菌种进行鉴定.结果:筛选出3株性能较好的醋酸菌株,分别命名为HY05、HY19与HY36,其中HY05菌株性能最优,能够耐受14%的酒精浓度,起始酒精浓度为10%时酒精转化最快,产酸速度快,所生产的果醋色泽淡黄,质地滑清透亮,风味芳香怡人;根据形态观察与Vitek-32系统的分析结果,将其鉴定为醋杆菌属的巴氏醋杆菌(Acetobacter pasteurianus),命名为A.pasteurianus HY05.结论:A.pasteurianus HY05适宜胡柚果醋的生产.

  7. Analysis of energetic metabolism of Acetobacter pasteurianus during high acidic vinegar fermentation%巴氏醋杆菌高酸度醋发酵过程的能量代谢分析

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    亓正良; 杨海麟; 夏小乐; 王武; 余晓斌

    2013-01-01

    [目的]初步分析了Acetobacter pasteurianus CICIM B7003-02在醋酸发酵过程中的能量代谢状况,通过强化细胞能量代谢水平以提升菌株高酸发酵的产酸强度.[方法]探明A.pasteurianus CICIM B7003-02在高酸度醋发酵的不同阶段中三羧酸循环底物含量、乙醇呼吸链酶活及能量代谢酶基因的转录水平等代谢特点,分析用于醋酸发酵的产能代谢途径及其作用.[结果]发现A.pasteurianus CICIM B7003-02在醋酸发酵初期,主要通过苹果酸/琥珀酸回补偶联有氧呼吸途径产能.进入醋酸快速积累阶段,乙醇呼吸链为主要供能代谢途径.发酵后期苹果酸/琥珀酸回补途径配合乙醇呼吸链供能.基于上述研究,采取添加琥珀酸和苹果酸强化细胞产能,促进高酸度醋发酵强度.[结论]能量供给影响醋杆菌耐酸能力和醋酸生产能力.确定乙醇呼吸链为醋酸发酵的主要供能系统.强化细胞产能手段可达到提高醋酸发酵强度的目的.

  8. 醋酸杆菌发酵细菌纤维素及其改性研究%Study on fermentation of bacterial cellulose by Acetobacter xylinum and its modification

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    张雯; 赵秋红; 李彦军

    2013-01-01

    为提高细菌纤维素再溶胀能力,改善细菌纤维素(BC)材料特性,以醋酸杆菌(Acetobacter xylinum)为生产菌株,通过向发酵培养基中分别添加水溶性多糖-羧甲基纤维素钠(CMCNa)、羧甲基淀粉钠(CMSCNa)、海藻酸钠(AS)发酵生产细菌纤维素及把普通细菌纤维素凝胶膜分别浸渍在多羟基化合物-1,3-丁二醇、N,N-二甲基甲酰胺、甘油中两种方式对细菌纤维素进行了改性,对改性前后的细菌纤维素进行了红外(IR)检测、X衍射(XRD)检测及持水率、孔隙率、再溶胀能力、水蒸汽透过率等性能检测.结果表明:培养基中添加0.5% AS所得改性BC膜持水率比改性前提高了2%;培养基中加入0.5% AS所得改性BC膜及N,N-二甲基甲酰胺浸渍改性所得BC膜再溶胀能力比改性前提高了30%;培养基中加入1.5% CMCNa所得改性BC膜孔隙率比改性前提高了5倍.发酵改性对细菌纤维素的结晶度影响不大.

  9. Screening and Identification of Acetobacter spp.for Green Mume Fruit Vinegar Fermentation%青梅果醋醋酸发酵菌种的筛选与鉴定

    Institute of Scientific and Technical Information of China (English)

    杨颖; 刘欠欠; 陆胜民; 邢建荣; 夏其乐

    2010-01-01

    目的:筛选1株适合青梅果醋生产的醋酸菌种.方法:从自然发酵的青梅果醋中筛选醋酸菌种,研究其酒精耐受性、酒精消耗速度、产醋酸速度.发酵生产青梅果醋,时其进行感官分析.以ABI 377型DNA序列分析仪时最适菌种进行16S rRNA序列分析,鉴定其种属.结果:筛选出性能较好的3株醋酸菌株.分别命名为QM08、QM17与QM50,其中QM17菌株综合性能优,能够耐受13%的酒精,且起始酒精含量为10%时酒精转化较快,产酸速度较快.用本方法生产的果醋质量佳,色泽淡黄,质地澄清、透亮,风味芳香怡人.根据形态观察与16S rRNA序列分析,将其鉴定为醋杆菌属的巴氏醋杆菌(Acetobacter pasteurianus),命名为巴氏醋杆菌QM17.结论:巴氏醋杆菌QM17适宜青梅果醋的生产.

  10. Cloning and protein sequence analysis of alcohol dehydrogenase of Acetobacter pasteurianus AC2005%巴斯德醋酸杆菌AC2005乙醇脱氢酶基因克隆与蛋白序列分析

    Institute of Scientific and Technical Information of China (English)

    张科平; 郑宇; 贾钧辉; 骆健美; 王敏

    2011-01-01

    以具有优良醋酸发酵性能的巴斯德醋酸杆菌AC2005基因组DNA为模板,利用PCR的方法分别克隆了编码乙醇脱氢酶亚基Ⅰ和乙醇脱氢酶亚基Ⅱ的基因adhA和adhB。序列分析表明,adhA与GenBank已报道的序列(accessio nnumber:D13893.1)具有94%的同源性,氨基酸序列同源性达98%;adhB与GenBank已报道的序列(accession number:D13893.1)同源性为93%,氨基酸序列同源性达97%。利用TMHMM 2.0软件,对乙醇脱氢酶跨膜结构进行了分析,发现乙醇脱氢酶亚基Ⅰ和乙醇脱氢酶亚基II均为膜结合蛋白。利用Swiss-Model在线软件模拟了巴斯德醋酸杆菌AC2005乙醇脱氢酶亚基I的三维立体结构。该研究对该酶的结构和功能的进一步分析提供了基础。%The genes,adhA and adhB,coding the subunit I and II of alcohol dehydrogenase(ADH)were amplified by the polymerase chain reaction(PCR),using genomic DNA of Acetobacter pasteurianus AC2005 as template,which had been demonstrated a potential strain for acetic acid production. The sequences were blasted in GenBank databases. The results showed that adhA shared 94% identity and 98% amino acid sequence homology,besides adhB shared 93% identity and 97% amino acid sequence homology with the reported gene(accession number:D13893. 1). The characterization of transbilayer helix of ADH was analyzed,using software of TMHMM 2. 0. It was found that the subunits I and II were both membrane-bound protein. Furthermore,the three dimensional structure of subunit I of ADH in A. pasteurianus AC2005 was produced by using Swiss-Model workspace. Those results provided that some information for further researching the relationship of structure and function of ADH.

  11. Physiological response to acetic acid stress of the Acetobacter pasteuranus HN 1.01 during liquid-preservation%巴氏醋酸杆菌沪酿1.01对液体保藏中醋酸胁迫的生理应答

    Institute of Scientific and Technical Information of China (English)

    马新凤; 陈义伦; 周波; 李超男; 吴慧; 黄颖倩; 张玉环; 郭莎莎

    2016-01-01

    Acetobacter pasteurianus Huniang 1.01为试验菌株,采用不同醋酸酸度保藏液保藏醋酸菌,每周检测活菌数、酸度、乙醇脱氢酶(Alcohol dehydrogenase,ADH)、乙醛脱氢酶(Acetaldehyde dehydrogenase,ALDH)活性及细胞多糖含量随保藏时间的变化,通过显微镜观察醋酸菌细胞形态,采用气相色谱-质谱联用(gas chromatography-mass spectrometry,GC-MS)分析细胞膜脂肪酸成分的变化.结果表明,活菌数先缓慢后快速地减少,脱氢酶系活性呈现波动变化状态,酸度变化幅度很小,呈平缓上升趋势;随着酸度的过度上升,活菌数、ADH、ALDH活性降低,醋酸菌的生长和产酸代谢活动受到抑制,细胞形态由规则的椭圆形变为不规则的长棒杆状,细胞多糖含量增加,细胞膜不饱和脂肪酸的相对含量显著提高.初步断定Acetobacter pasteurianus Huniang 1.01主要依靠改变乙醇呼吸链酶活力、细胞形态、细胞膜脂肪酸组分,增加细胞荚膜多糖的分泌和细胞膜的流动性等机制的协同作用来适应液体保藏过程中醋酸胁迫产生的不良环境.

  12. Sequential Design Optimization of Bacterial Cellulose Production by Acetobacter xylinus Using Chayote (Sechium edule)Juice as the Basal Fermentation Medium%序贯设计优化佛手瓜汁生产细菌纤维素工艺

    Institute of Scientific and Technical Information of China (English)

    李家洲; 肖玉平; 黄荣林; 赵鑫

    2011-01-01

    在以佛手瓜汁为原料利用木醋杆菌(Acetobacter xylinus)发酵生产细菌纤维素的过程中,利用Plackett-Burman 分部析因试验设计确定出蔗糖质量浓度和pH值对产量具有显著影响,再利用最速爬坡试验确定出这两个因素的中心点,最后以中心点进行中心组合试验设计,建立试验空间下的模型,优化出最佳的因素水平为温度28℃、(NH4)2SO2质量浓度0.3g/l00mL、佛手瓜汁用量(体积分数)100%、蔗糖质量浓度6.54g/l00mL、pH4.19.在最优条件下可得最大干基产量为4.18g/L.

  13. 巴氏醋杆菌核酸修复酶UvrA对大肠杆菌耐受性的影响%Effect of Repair Excinuclease UvrA fromAcetobacter pasteurianus on the Tolerance ofEscherichia coli

    Institute of Scientific and Technical Information of China (English)

    郑宇; 陈兴京; 王靖; 牟俊; 王敏

    2016-01-01

    Acetobacter pasteurianus is commonly used for acetic acid fermentation due to its high acetic acid tolerance. Excinuclease UvrA is related with the tolerance of microorganisms to environmented presses such as acid and heat. In this research,the gene of excinuclease UvrA was cloned fromA. pasteurianus and expressed inEscherichia coli to study its effect on the tolerance ofE. coli to acetic acid,low pH,heat and peroxide. The result showed that the survival rate ofE. coli JM109/pMV24-uvrA was 11.2,4.7,19.2,and 7.5 times ofE. coli JM109/pMV24,respectively,after the treatment with 0.5%, acetic acid,pH 3,53,℃ and 0.15% H2O2 for about 40 min. All these demonstrate that the expression of UvrA fromA. pasteurianus could increase the tolerance of E. colito acetic acid,low pH,heat and peroxide. The reason could be that UvrA has increased the protection or repair ability of the strains under pressure.%巴氏醋杆菌(Acetobacter pasteurianus)具有较高的醋酸耐受性,常用于醋酸的发酵生产.微生物中核酸修复酶UvrA与菌体对酸、热等不良环境的耐受性相关,本论文克隆巴氏醋杆菌AC2005中的核酸修复酶基因uvrA,并在大肠杆菌(Escherichia coli)中重组表达,研究其对大肠杆菌醋酸、低pH、热和过氧化胁迫条件耐受性的影响.结果表明,分别在0.5%,醋酸、pH 3、53,℃、0.15%,H2O2这4种胁迫条件下处理40,min后,重组菌E.,coli JM109/pMV24-uvrA的存活率分别是对照菌E.,coli JM109/pMV24的11.2、4.7、19.2和7.5倍,说明来源于巴氏醋杆菌的核酸修复酶UvrA能够提高大肠杆菌对醋酸、低 pH、热与过氧化的耐受性,其原因可能是由于重组表达 UvrA 提高了菌体在不同胁迫条件下对DNA的保护或修复能力.

  14. 响应面法优化木醋杆菌发酵酿酒丢糟水解液产细菌纤维素培养基及其产物性能%Optimization of Culture Medium Based on Vinasse Hydrolysate for Acetobacter xylinum by Response Surface Methodology for Enhanced Production of Bacterial Cellulose and Properties of the Product

    Institute of Scientific and Technical Information of China (English)

    张雯; 刘康; 罗霏霏; 张敏娟; 李彦军

    2015-01-01

    为提高木醋杆菌(Acetobacter xylinum)发酵酿酒丢糟水解液生产细菌纤维素(bacterial cellulose,BC)的产量,采用响应面法对发酵培养基进行了优化,同时比较了发酵产物BC的性能和结构.通过单因素及响应面试验结果确定木醋杆菌发酵酿酒丢糟水解液生产BC的最佳培养基配方为:蔗糖39.33 g、蛋白胨20.01 g、MgSO4 0.91 g、柠檬酸钠3.45 g、黄嘌呤1.02 g、乙醇10mL、酒糟水解液1 000 mL、pH 6.0.在此条件下BC的产量为6.27 g/L,较优化前(4.4 g/L)提高了42.5%.利用傅里叶红外光谱、X射线衍射、扫描电子显微镜对发酵产物BC的性能和结构进行了比较,结果表明,酒糟水解液发酵产物BC结构性能与基本培养基发酵产物BC的基本一致,说明酒糟水解液能够替代部分发酵原料发酵生产BC,且不影响BC性能.

  15. Effect of synergistic factor on the substances change of fermentation liquid with bacterial cellulose-producing Acetobacter xylinum%增效因子对木醋杆菌产细菌纤维素发酵液中物质变化的影响

    Institute of Scientific and Technical Information of China (English)

    贾青慧; 卢红梅; 陈莉; 张丽平

    2016-01-01

    在木醋杆菌(Acetobacter xylinum)产细菌纤维素(BC)培养基中,添加一定量的增效因子,考察增效因子椰子水、玉米浆、Tween-80、羧甲基纤维素(CMC)、烟酸和生物素对发酵液中细菌纤维素产量、总糖、总酸和有机酸含量的影响.结果表明,10%玉米浆及60%椰子水对细菌纤维素产量的增效作用最强,细菌纤维素产量分别为8.534 g/L、6.008 g/L,与空白组相比,分别增加了4.67、2.99倍;添加60%椰子水,可以促进总糖含量降低,有利于木醋杆菌合成BC.添加各增效因子后发酵液内总酸含量变化基本一致,整体均呈下降的趋势.10%玉米浆试验组有机酸含量最高,且其中葡萄糖酸、乳酸、乙酸和丁二酸等主体酸所占比例大,这与10%玉米浆对BC产量较为明显的增效作用有一定关系.

  16. Biocatalytic Asymmetric Oxidation of Racemic 1-(4-Methoxyphenyl) Ethanol Using Immobilized Acetobacter sp. CCTCC M209061 Cells in Organic Solvent-containing Biphasic System%有机溶剂/缓冲液双相体系中固定化Acetobactersp. CCTCCM209061细胞催化1-(4-甲氧基)-苯基乙醇不对称氧化反应

    Institute of Scientific and Technical Information of China (English)

    程景; 娄文勇; 宗敏华

    2014-01-01

    在有机溶剂/缓冲液双相体系中,利用固定化醋酸杆菌 Acetobacter sp. CCTCC M209061细胞高对映体选择性地催化1-(4-甲氧基)-苯基乙醇(MOPE)的不对称氧化反应,成功地拆分外消旋 MOPE 得到对映体纯(S)-MOPE.与游离细胞相比,固定化细胞催化反应速度有所降低,但其稳定性(包括操作稳定性、热稳定性和储藏稳定性)明显提高.固定化细胞连续使用10批次(每批次12 h)后,仍能保留其初始催化活性的58%以上,而游离细胞仅保留约20%的相对活性.在所考察的不同有机溶剂中,正己烷不仅能较好地溶解底物,而且对细胞的生物相容性相对较好,因而提高了反应底物浓度、反应初速度、对映体回收率及残留底物 e. e.值,是反应体系中最适宜的有机相.该反应的最适宜正己烷体积分数为60%,辅底物为50 mmol/ L 丙酮,底物浓度为40 mmol/ L,缓冲液 pH=6.5,反应温度为30℃;在此条件下,反应初速度为80.4μmol/ min,反应12 h 后,对映体回收率和残留底物 e. e.值分别为51.0%和99.9%,明显好于水单相反应体系.%The resolution of racemic 1-(4-methoxyphenyl) ethanol ( MOPE) to enantiopure ( S)-MOPE through highly enantioselective oxidation of MOPE with immobilized Acetobacter sp. CCTCC M209061cells was successfully conducted in organic solvent-containing biphasic system. In spite of exhibiting relatively slower reaction rate than free cells, immobilized cells of Acetobacter sp. CCTCC M209061 showed much higher stabili-ty, including operational stability, thermal stability and storage stability. The immobilized cells still retained more than 58% of its original catalytic activity after being repeatedly used for 10 batches(12 h per batch), and the free cells maintained only around 20% of relative activity. Among various organic solvents examined, use of n-hexane as the second phase in a two-phase system enhanced the concentration of substrate, the initial reaction rate, the

  17. Bacterial cellulose membrane produced by Acetobacter sp. A10 for burn wound dressing applications.

    Science.gov (United States)

    Kwak, Moon Hwa; Kim, Ji Eun; Go, Jun; Koh, Eun Kyoung; Song, Sung Hwa; Son, Hong Joo; Kim, Hye Sung; Yun, Young Hyun; Jung, Young Jin; Hwang, Dae Youn

    2015-05-20

    Bacteria cellulose membranes (BCM) are used for wound dressings, bone grafts, tissue engineering, artificial vessels, and dental implants because of their high tensile strength, crystallinity and water holding ability. In this study, the effects of BCM application for 15 days on healing of burn wounds were investigated based on evaluation of skin regeneration and angiogenesis in burn injury skin of Sprague-Dawley (SD) rats. BCM showed a randomly organized fibrils network, 12.13 MPa tensile strength, 12.53% strain, 17.63% crystallinity, 90.2% gel fraction and 112.14 g × m(2)/h highest water vapor transmission rate (WVTR) although their swelling ratio was enhanced to 350% within 24h. In SD rats with burned skin, the skin severity score was lower in the BCM treated group than the gauze (GZ) group at all time points, while the epidermis and dermis thickness and number of blood vessels was greater in the BCM treated group. Furthermore, a significant decrease in the number of infiltrated mast cells and in vascular endothelial growth factor (VEGF) and angiopoietin-1 (Ang-1) expression was observed in the BCM treated group at day 10 and 15. Moreover, a significant high level in collagen expression was observed in the BCM treated group at day 5 compared with GZ treated group, while low level was detected in the same group at day 10 and 15. However, the level of metabolic enzymes representing liver and kidney toxicity in the serum of BCM treated rats was maintained at levels consistent with GZ treated rats. Overall, BCM may accelerate the process of wound healing in burn injury skin of SD rats through regulation of angiogenesis and connective tissue formation as well as not induce any specific toxicity against the liver and kidney. PMID:25817683

  18. Crystallization and preliminary crystallographic analysis of the cellulose biosynthesis-related protein CMCax from Acetobacter xylinum

    Energy Technology Data Exchange (ETDEWEB)

    Kawano, Shin; Yasutake, Yoshiaki; Tajima, Kenji; Satoh, Yasuharu; Yao, Min, E-mail: yao@castor.sci.hokudai.ac.jp; Tanaka, Isao; Munekata, Masanobu

    2005-02-01

    The cellulose biosynthesis-related protein CMCax from A. xylinum has been purified and crystallized. The crystals of CMCax belong to the primitive hexagonal space group P6{sub 1} or P6{sub 5}, with unit-cell parameters a = b = 89.1, c = 94.2 Å.

  19. Acetobacter tropicalis is a major symbiont of the olive fruit fly (Bactrocera oleae)

    DEFF Research Database (Denmark)

    Kounatidis, Ilias; Crotti, Elena; Sapountzis, Panagiotis;

    2009-01-01

    Following cultivation-dependent and -independent techniques, we investigated the microbiota associated with Bactrocera oleae, one of the major agricultural pests in olive-producing countries. Bacterial 16S rRNA gene libraries and ultrastructural analyses revealed the presence of several bacterial...

  20. Effect of Organic Acids on Bacterial Cellulose Produced by Acetobacter xylinum

    Directory of Open Access Journals (Sweden)

    Hongmei Lu

    2016-03-01

    Full Text Available Based on the difference of bacterial cellulose production from rice saccharificate medium and chemical medium under static cultivation, effect of organic acids in the process of bacterial cellulose produced by A. xylinum was studied. The results showed that the kinds and contents of organic acids were different in both culture medium, in which accumulated oxalic acid and tartaric acid inhibited A. xylinum producing BC in chemical medium, while pyruvic acid, malic acid, lactic acid, acetic acid, citric acid and succinic acid, as ethanol, promoted A. xylinum to produce BC. Compared to the blank BC production 1.48 g/L, the optimum addition concentrations of pyruvic acid, malic acid, lactic acid, acetic acid, citric acid, succinic acid, and ethanol in chemical medium were 0.15%, 0.1%, 0.3%, 0.4%, 0.1%, 0.2% , 4% and the BC productions were 2.49 g/L, 2.83 g/L, 2.12 g/L, 2.54 g/L, 2.27 g/L, 1.88 g/L , 2.63 g/L, respectively. The co-existence of above organic acids and ethanol increased BC production even further.

  1. Production of nano bacterial cellulose from waste water of candied jujube-processing industry using Acetobacter xylinum.

    Science.gov (United States)

    Li, Zheng; Wang, Lifen; Hua, Jiachuan; Jia, Shiru; Zhang, Jianfei; Liu, Hao

    2015-04-20

    The work is aimed to investigate the suitability of waste water of candied jujube-processing industry for the production of bacterial cellulose (BC) by Gluconacetobacter xylinum CGMCC No.2955 and to study the structure properties of bacterial cellulose membranes. After acid pretreatment, the glucose of hydrolysate was higher than that of waste water of candied jujube. The volumetric yield of bacterial cellulose in hydrolysate was 2.25 g/L, which was 1.5-folds of that in waste water of candied jujube. The structures indicated that the fiber size distribution was 3-14 nm in those media with an average diameter being around 5.9 nm. The crystallinity index of BC from pretreatment medium was lower than that of without pretreatment medium and BCs from various media had similar chemical binding. Ammonium citrate was a key factor for improving production yield and the crystallinity index of BC.

  2. Possible participation of transient sheets of 1. -->. 4-. beta. -glucans in the biosynthesis of cellulose I. [Acetobacter xylinum

    Energy Technology Data Exchange (ETDEWEB)

    Colvin, J.R.

    1983-01-01

    It is suggested that a primary, essential stage in the biologic formation of a microfibril of cellulose I is an extracellular, lateral association of presynthesized (1..-->..4)-..beta..-D-glucans, by hydrogen bonding, to form long, thin sheets. These sheets then superimpose themselves nonenzymatically by London forces to form the nascent microfibril. The ends of the constituent glucans of the nascent microfibril may undergo extension or rearrangement of the type indicated by Maclachlan and colleagues. The formation of the metastable, native structure (cellulose I) may be deduced from the above suggestion as a natural consequence of closest packing of the sheets. The irreversibility of the change from cellulose I to cellulose II, either by mercerization or regeneration, also follows from the postulate. The suggestion also explains why cellulose microfibrils and chitin microfibrils may be formed contiguously in cell walls without interfering with each other. High-resolution electron micrographs of the tips of newly formed microfibrils of bacterial cellulose which had been very lightly negatively stained with sodium phosphotungstate are consistent with the suggestion. 33 references, 3 figures.

  3. Production of nano bacterial cellulose from waste water of candied jujube-processing industry using Acetobacter xylinum.

    Science.gov (United States)

    Li, Zheng; Wang, Lifen; Hua, Jiachuan; Jia, Shiru; Zhang, Jianfei; Liu, Hao

    2015-04-20

    The work is aimed to investigate the suitability of waste water of candied jujube-processing industry for the production of bacterial cellulose (BC) by Gluconacetobacter xylinum CGMCC No.2955 and to study the structure properties of bacterial cellulose membranes. After acid pretreatment, the glucose of hydrolysate was higher than that of waste water of candied jujube. The volumetric yield of bacterial cellulose in hydrolysate was 2.25 g/L, which was 1.5-folds of that in waste water of candied jujube. The structures indicated that the fiber size distribution was 3-14 nm in those media with an average diameter being around 5.9 nm. The crystallinity index of BC from pretreatment medium was lower than that of without pretreatment medium and BCs from various media had similar chemical binding. Ammonium citrate was a key factor for improving production yield and the crystallinity index of BC. PMID:25662694

  4. 巴氏醋酸杆菌纤维素合成条件初探%Condition of Acetobacter pasteurianum bacterial cellulose fermentation

    Institute of Scientific and Technical Information of China (English)

    周媛; 邵伟; 涂志英; 黎姝华

    2000-01-01

    通过试验探索出巴氏醋酸杆菌在蛋白胨1.0%、 *!酵母浸膏0.5%、蔗糖2.0%、柠檬酸0.115%、乙醇1%、Na2HPO40.5%,pH6.0培养基中,合成纤维素的最佳条件:30℃,静置培养6d,细菌纤维素最大产量可达9.85g/L.

  5. Study on debittering of citrus juices limonin by acetobacter%醋酸菌脱除柑桔汁柠碱苦味的研究

    Institute of Scientific and Technical Information of China (English)

    罗自生; 张惟广; 曾凡坤; 吴永娴

    2001-01-01

    研究了用醋酸杆菌脱除柑桔汁中柠碱苦味的菌株筛选,选择性培养条件的确定,研究表明:醋酸杆菌AS 1.01、AS 1.216、AS1.41、AS 1.44四个菌株中以AS1.41的脱苦能力最强.其选择性培养条件为:温度25℃,摇床转速150 r/min,添加 1%乙醇于液体培养基,此培养条件下脱苦率达58.3%.

  6. INVESTIGATION OF OPTIMAL MEDIUM COMPOSITION FOR MICROBIAL CELLULOSE PRODUCTION BY ACTEBACTER XYLINUM%Acetobacter xylinum生产纤维素的最适培养基成分

    Institute of Scientific and Technical Information of China (English)

    余晓斌; 卞玉荣; 全文海

    1999-01-01

    探索出胶醋杆菌在摇瓶培养最适培养基成分为蛋白胨浓度1.0%、酵母膏0.5%、葡萄糖浓度2.0%、柠檬酸0.115%、乙醇1%、Na2HPO40.5%,pH6.0,160r/min的条件下进行摇瓶培养,细菌纤维素最大产量为7.55g/l.

  7. Selection and biochemical characteristics of high-yield Acetobacter%高产醋酸菌的筛选及其形态生化特征研究

    Institute of Scientific and Technical Information of China (English)

    张忠明

    2006-01-01

    从天然发酵醋醅中分离得到了32株醋酸菌,经初筛、复筛产酸试验,筛选出了J4和J8 2株醋酸菌.采用紫外线诱变处理始发J4菌株,经分离筛选获得产醋酸能力高的醋酸菌J4-1和J4-4,产酸量分别为85.44 g/L和87.56 g/L,J4-4产酸量比菌株J4(84.19 g/L)提高了4 %,并对J4-4菌株的形态生化特征进行了研究.

  8. 开菲尔粒中一株醋酸菌的分离鉴定%Isolation and Identification of an Acetobacter Bacteria KAB7 from Kefir Grains

    Institute of Scientific and Technical Information of China (English)

    陈卫红; 沈伟达; 阳大海; 鲁水龙; 郑武; 于岚

    2010-01-01

    [目的]从开菲尔粒中分离并鉴定醋酸菌,为研究醋酸菌在开菲尔饮品发酵及开菲尔粒形成机理提供理论及技术基础.[方法]将开菲尔粒粉碎后制备成不同稀释浓度的菌悬液,涂布于筛选培养基上,37 ℃条件下培养7 d,挑选单菌落进行形态观察、生理生化试验,并扩增其16S rRNA基因,测序鉴定.[结果]筛选到一株醋酸菌--KAB7.[结论]根据该菌形态观察、生理生化试验结果以及16S rRNA测序比对,鉴定为巴氏醋杆菌巴氏亚种.

  9. Functional Bradyrhizobium japonicum NifA expression under a hybrid nptII-nifH promoter in E. coli and Acetobacter diazotrophicus SRT4.

    Science.gov (United States)

    Menéndez, C; Selman-Housein, G; Arrieta, J G; Coego, A; Hernández, L

    1998-01-01

    A hybrid promoter consisting of the in tandem fusion of the Tn5 nptII and the Klebsiella pneumoniae nifH promoters was constructed to study the functionality of the nif genes transcriptional activator NifA from Bradyrhizobium japonicum in two different host bacteria. beta-galactosidase experiments in E. coli revealed that the hybrid nptII-nifH promoter can behave as a constitutive or a NifA-inducible promoter depending on the aeration conditions. Expression of the B. japonicum NifA from the hybrid nptII-nifH promoter (plasmid pBPF204) induced "in trans" lacZ transcription from the Azotobacter chroococcum nifH promoter in E. coli and A. diazotrophicus cells grown at low pO2. Similarly, the plasmid pBPF204 increased nitrogenase activity in A. diazotrophicus cells grown under microaerobic conditions. Based on these results, we suggest that the B. japonicum NifA could function as an efficient O2-sensitive transcriptional activator of nif genes in genetically distant diazotrophic bacteria. PMID:10932742

  10. Study on Bacterial Cellulose Production by Acetobacter Xylinum NUST4. 2 in Shake Flask Culture and Its Application%Acetobacter xylinum NUST4.2摇瓶培养高产细菌纤维素及应用研究

    Institute of Scientific and Technical Information of China (English)

    孙东平; 周伶俐; 杨加志; 马波; 朱春林; 刘长生

    2008-01-01

    添加生长因子于Acetobactet-zylinum NUST4.2的基础培养基中,优化的发酵培养基为:葡萄糖18 g,蔗糖21 g,玉米浆干粉20 g,硫酸铵4 g,磷酸二氢钾2 g,硫酸镁0.4 g,醋酸1.4 mL,乙醇4 mL,硫酸亚铁2 mg,烟酰胺0.6 mg,对氨基苯甲酸0.6 mg,蛋氨酸3 mg,水1 L.采用该优化培养基,动态条件下纤维素产量达7.16 g·L-1,是基础培养基的9.7倍.将动态·细菌纤维素进行匀浆处理后,与两种植物纤维纸浆配合抄纸,结果发现添加细菌纤维素能提高纸张的机械性能和防水性.

  11. 玉米浆做Acetobacter xylinum培养基生产纤维素的发酵条件优化%Study on the fermentation condition for the production of cellose by Acetobacter xylinum using corn syrup as the medium

    Institute of Scientific and Technical Information of China (English)

    张凤清; 张海悦; 郑春雨; 彭悦; 解丛林

    2005-01-01

    以玉米浆作为木醋杆菌营养氮源,探索出发酵培养基的最优配方,并利用单因素优选法对发酵条件进行了优化.结果表明,葡萄糖4%,玉米浆5.5%,磷酸氢二钠0.5%,生物素25mg/L,咖啡因2mg/L,柠檬酸0.1%,pH为6,利用木醋杆菌静止浅层培养法,纤维素的产量高迭7.22g/L,比酵母膏做氮源的纤维素产量提高了1倍.

  12. Scale-up production of yacon fruit vinegar by Acetobacter%醋酸杆菌发酵雪莲果生产果醋饮料工程放大实验研究

    Institute of Scientific and Technical Information of China (English)

    黄晓宾; 罗荣华; 张茜; 黄彪; 李媛媛; 唐湘华

    2011-01-01

    Using yacon fruits as main raw materials, yacon fruit vinegar was produced by two stages of alcoholic fermentation and acetic fermentation in 200L fermentor. The fermentation time was 200h and acetic acid concentration could reach 24.18g/L. The components of fermentation product were analyzed by GC-MS. The content of acid material reached 82.34%, in which, acetic acid content was 74.70%. The scale-up experiments provided an important reference for development of liquid fermentation fruit vinegar beverage.%通过以雪莲果为主要原料在200L发酵罐中经过酒精发酵和醋酸发酵2个阶段,获得雪莲果果醋产物,总发酵时间为200h,醋酸浓度可达到24.18g/L,对发酵产物进行GC-MS分析,发酵产物中酸类物质的含量占82.34%,其中醋酸的含量占到总量的74.70%.该放大实验的研究为液态发酵果醋饮料的发展和技术提升提供了重要的基础.

  13. 醋酸杆菌醇脱氢酶粗酶液的特性研究%Properties of Alcohol Dehydrogenase(ADH)Preparation from Acetobacter sp.CCTCC M209061

    Institute of Scientific and Technical Information of China (English)

    肖仔君; 黄国清; 钟瑞敏

    2010-01-01

    乙醇脱氢酶(ADH)是醋酸杆菌发酵生产醋酸的关键酶.以硫酸铵为沉淀剂,采用盐析法对醋酸杆菌中乙醇脱氢酶进行初步的分离纯化,并研究其酶学特性.结果表明:ADH比活力从粗酶液的0.201 U/mg提高到0.460 U/mg,纯化倍数为2.289;其最适作用pH值为7.5~8.0,pH值为7.8时酶活力达到最大,pH值为7.0时酶较为稳定;最适作用温度为35℃,温度为30℃~40℃时酶活力较为稳定,温度超过45℃后酶活力急剧下降.通过对乙醇底物浓度对ADH活力影响的研究,ADH对乙醇的米氏常数Km为2.59×10-2mol/L.

  14. Screening of High Cellulose Producting Acetobacter xylinum and Optimization of Its Fermentation Process%高产纤维素木醋杆菌的筛选及其发酵工艺优化

    Institute of Scientific and Technical Information of China (English)

    2016-01-01

    我国细菌纤维素生产存在的主要问题有产量低、成本高等.本实验通过诱变筛选出一株较佳产细菌纤维素生产菌,利用玉米糖化液为碳源,对其发酵工艺进行优化研究,获得了较好效果,对于提高细菌纤维素产量,降低发酵成本均有较好的效果,也为细菌纤维素的工业化生产提供了理论依据和实践基础.

  15. STUDY ON BACTERIAL CELLULOSE PRODUCTION BY STATIC CULTURE OF ACETOBACTER XYLINUM%木醋杆菌静态培养生产细菌纤维素的研究

    Institute of Scientific and Technical Information of China (English)

    苏建宇; 乔长晟

    2001-01-01

    静态培养条件下,木醋杆菌纤维素产量取决于培养基的成分和液层深度.采用GPY培养基ф90mm培养皿中,以培养基体积为30mL-,液层深度为5mm时纤维素产量最高,达4.1mg.mL-,液层过深或过浅均不利于纤维素的产生.培养基分别以果糖、蔗糖和葡萄糖为唯一碳源时,果糖作为碳源细菌纤维素产量最高,达6.3mg·mL-;蔗糖为碳源时次之,为5.4mg·mL-;而葡萄糖为碳源时细菌纤维素产量最低,为3,9mg·mL-.

  16. Fermentation Condition of Bacterial Cellulose by Acetobacter xylinum M096%木醋杆菌M096生产细菌纤维素的发酵条件

    Institute of Scientific and Technical Information of China (English)

    王红艳; 王申涛

    2010-01-01

    探讨温度、初始pH值、碳源和氮源对细菌纤维素产量的影响,以确定生产菌株发酵生产细菌纤维素的条件.结果显示,木醋杆菌M096发酵生产细菌纤维素的培养条件是:发酵温度25℃,初始pH值最适范围是5.8~6.6,最佳碳源为蔗糖且最适浓度是8%,最佳氮源为牛肉膏且最适浓度是1.5%.

  17. 柑桔果醋发酵用醋酸菌筛选及特性研究%Selection and Characteristics of High-yield Acetobacter in Citrus Vinegar Fermentation

    Institute of Scientific and Technical Information of China (English)

    程世春

    2010-01-01

    从水果中分离得到41株醋酸菌,经过初筛和复筛产酸实验,筛选到一株高产醋酸菌株Ac1.3,该菌以桔汁和桔皮为原料,产酸量分别为38.35g/L 和38.46g/L,并对Ac1.3菌株的培养及柑桔果醋酿制特性进行了研究.

  18. Screen and identification of Acetobacter about grape skin vinegar from natural fermentation%自然发酵的葡萄皮醋中醋酸菌的分离鉴定

    Institute of Scientific and Technical Information of China (English)

    何文兵; 刘雪莲; 马冬雪

    2012-01-01

    The grape skin vinegar from natural fermentation was taken as a sample, acetic acid bacteria was isolated through purification and qualitative test from it. The six good acetic acid bacteria was isolated through morphology, physiological and biochemical characteristics test and preliminary identification. Finaliy, a good strain G4 was isolated through the determination of continue test, acid yield test and alcohol resistance test. The acid yield amount can reach 31.05g/L.%以自然发酵的葡萄皮醋为样品,采用分离纯化培养、定性试验等方法,从中筛选出醋酸菌,再通过形态特征以及生理生化等初步鉴定以及初筛试验筛选出6株优势醋酸,再经过复筛、产酸量、耐酒精度等试验后,最终筛选出一株产酸量为31.05g/L的醋酸菌.

  19. 发酵条件对木醋杆菌合成细菌纤维素影响的研究进展%Effects of Fermentation Conditions on Biosynthesis of Bacteria Cellulose by Acetobacter xylinum

    Institute of Scientific and Technical Information of China (English)

    马霞; 王瑞明; 关凤梅; 贾士儒

    2005-01-01

    产细菌纤维素能力较强的微生物是木醋杆菌.影响较大的发酵条件有:①培养基中含有乳酸盐或甲硫氨酸,能加速细胞生长,提高纤维素产量.②当氧分压为大气压的10%~15%时,纤维素的产量最高.提高溶氧会使气相的CO2分压同时加大,而降低纤维素的生产速率.③在发酵培养基中加入醋酸作为能源,能保持培养基中pH的稳定,有利于纤维素的生成.④在培养基中添加少量纤维素酶可提高纤维素的产量.分别添加1.5%的乙醇,0.1%的醋酸,0.2%的柠檬酸,纤维素的产量可分别提高59.5%,44.4%和40.5%.(陶然)

  20. Tissue cultured plantlets of sweet potato inoculated with the nitrogen-fixing bacterium Acetobacter diazotrophicus%甘薯组培苗接种固氮醋酸杆菌的初步研究

    Institute of Scientific and Technical Information of China (English)

    宋亚娜; 郑伟文

    2001-01-01

    固氮醋酸杆菌是一种从甘蔗中分离的固氮细菌。通过对组织培养的甘薯进行接种,发现固氮醋酸杆菌可以侵染到甘薯体内并定殖;指示剂显色反应和从接种植株体再分离细菌结果显示,固氮醋酸杆菌可以从根系或茎基部的伤口进入植株体内,并可到达根、茎、叶等器官中定殖;研究还发现接种固氮醋酸杆菌可以显著提高甘薯组培苗的生物量和叶片叶绿素含量,表明其有利于植株生长和氮营养的改善。%Tissue cultured plantlets of sweet potato were inoculated withA.diazotrophicus originally isolated from field-grew sugarcane.The results showed that the plantlet of sweet potato could be infected by A.diazotrophicus. The bacterium on and within the plant tissues were confirmed by the color change from green to dark orange of medium.The chlorophyll content and fresh weight of asepticsweet potato plantlet inoculated with A.diazotrophicus was higher than those of asepticsweet potato plant without A.diazotrophicus.

  1. Fabrication of living soft matter by symbiotic growth of unicellular microorganisms

    NARCIS (Netherlands)

    Das, Anupam A.K.; Bovill, James; Ayesh, Maram; Stoyanov, Simeon D.; Paunov, Vesselin N.

    2016-01-01

    We report the fabrication of living soft matter made as a result of the symbiotic relationship of two unicellular microorganisms. The material is composed of bacterial cellulose produced in situ by acetobacter (Acetobacter aceti NCIMB 8132) in the presence of photosynthetic microalgae (Chlamydomo

  2. Evolution of Acetic Acid Bacteria During Fermentation and Storage of Wine

    OpenAIRE

    Joyeux, A.; Lafon-Lafourcade, S.; Ribéreau-Gayon, P.

    1984-01-01

    Acetic acid bacteria were present at all stages of wine making, from the mature grape through vinification to conservation. A succession of Gluconobacter oxydans, Acetobacter pasteurianus, and Acetobacter aceti during the course of these stages was noted. Low levels of A. aceti remained in the wine; they exhibited rapid proliferation on short exposure of the wine to air and caused significant increases in the concentration of acetic acid. Higher temperature of wine storage and higher wine pH ...

  3. Volatile Fatty Acids and Ammonia Levels in Local Sheep’s Rumen Fluid Fed with Fermented Rice Straw

    Directory of Open Access Journals (Sweden)

    Sri Hidanah

    2016-04-01

    Full Text Available This study aims to determine the effects of providing suspension of Acetobacter liquefaciens bacterial isolate and Geotrichum sp. fungi isolate, as well as a mix between Acetobacter liquefaciens and Geotrichum sp. isolates extracted from the faeces of girrafes feeding on rice straw on pH value and Volatile Fatty Acids (VFA and ammonia levels in Local sheep’s rumen fluid. This experiment utilized twenty Local sheep randomly divided into four treatments where each treatment consisted of five repetitions, thus Completely Randomized Design method was applied (four treatments by five repetitions. The four treatments were T0: 60% (rice straw fermented without isolates+ 3% of urea + 3% of molasses + 40% of concentrates, T1: 60% (rice straw fremented with Acetobacter liquefaciens bacteria + 3% urea + 3% molasses + 40% of concentrates, T2: 60% (rice straw fermented with Geotrichum sp. fungi isolates + 3% of urea + 3% of molasses + 40% concentrates, and T3: 60% (fermented rice straw with Acetobacter liquefaciens and Geotrichum sp. isolates + 3% of urea + 3% of molasses + 40% of concentrates. The isolates of Acetobacter liquefaciens bacteria and Geotrichum sp. fungi were extracted from giraffes’ faeces kept in Safari Park, Pandaan, East Java. At the end of this three months study, the rumen fluid was collected using a vacuum pump. The variables were then measured including pH value and the levels of VFA and ammonia. The result of the research shows that local sheep fed with rice straw fermented with suspension of Acetobacter liquefaciens bacteria, Geotrichum sp. fungi, as well as a mixture of Acetobacter liquefaciens and Geotrichum sp. experienced an increase on their pH level as well as the VFA and ammonia levels in their rumen fluid the provision of the suspension of cellulolytic bacteria isolate mixture of Acetobacter liquefaciens and Geotrichum sp. fungi in the fermentation of rice straw yields the highest levels of acetic, propionic, butyric acids

  4. Optimization of Fermentation Medium for Alcohol Dehydrogenase Produced from Acetobacter sp.CCTCC M209061 by Response Surface Methodology%响应面设计优化醋酸杆菌产乙醇脱氢酶发酵培养基

    Institute of Scientific and Technical Information of China (English)

    肖仔君; 黄国清; 钟瑞敏

    2010-01-01

    利用响应面分析法优化醋酸杆菌产乙醇脱氢酶培养基.在单因素试验的基础上,采用Box-Behnken中心组合试验设计,选定碳源、氮源和生长因子3个因素为响应因子,以乙醇脱氢酶的酶活为响应值建立二次回归方程,相关系数R2 =0.9652,在分析各个因素的显著性和交互作用后,确定了醋酸杆菌产乙醇脱氢酶最优的培养基,即碳源15.1 g/L、氮源7.0 g/L、生长因子272.5 mL/L,在此条件下,乙醇脱氢酶活力理论响应值为0.352 U/mL ,验证值为0.349 U/mL.

  5. X-ray analysis of two antibiotic-synthesizing bacterial ester hydrolases : Preliminary results

    NARCIS (Netherlands)

    Barends, Thomas; Hensgens, Charles M.H.; Polderman-Tijmes, Jolanda J.; Jekel, P; de Vries, Erik; Janssen, Dick B.; Dijkstra, Bauke W.

    2003-01-01

    alpha-Amino-acid ester hydrolases are multimeric enzymes of potential use in antibiotic production. Knowledge of their structure could help to engineer these enzymes into economically viable biocatalysts. The alpha-amino-acid ester hydrolases from Xanthomonas citri and Acetobacter turbidans have bee

  6. 21 CFR 186.1839 - Sorbose.

    Science.gov (United States)

    2010-04-01

    ... microbial oxidation of sorbitol. It also occurs naturally in other plants. Sorbose can be synthesized by the catalytic hydrogenation of glucose to D-sorbitol. The resulting sorbitol can be oxidized by Acetobacter... migrates to food at levels not to exceed good manufacturing practice. (d) Prior sanctions for...

  7. LACTIC ACID AND ACETIC ACID BACTERIA ISOLATED FROM RED WINE

    Directory of Open Access Journals (Sweden)

    Attila Kántor

    2013-02-01

    Full Text Available The aim of our study was the identification of red wine microbiota during the fermentation process using a classical microbiological method and real-time PCR. The changes in different groups of microorganisms were monitored in total counts of bacteria, Lactobacillus cells and Acetobacter cells. Microbiological parameters were observed during the current collection and processing of wine in 2012. Samples were taken during the fermentation process in wine enterprises and were storaged with different conditions. During this period were examined 4 bottles of wine berween Cabernet Sauvignon and Frankovka modra. The total counts of bacteria ranged from 4.98±0.08 in the wine Cabernet Sauvignon at 4 °C of storage to 5.63±0.13 log CFU.ml-1 in the wine Cabernet Sauvignon at 25 °C of storage. The number of lactobacilli ranged from 2.18±0.10 in the Cabernet Sauvignon at 4 °C to 2.49±0.04 log CFU.ml-1 in the Frankovka modra wine at 25 °C of storage and the number of Acetobacter cells ranged from 4.21±0.04 in the Cabernet Sauvignon at 4 °C of storage to 4.52±0.15 log CFU.ml-1 in Cabernet Sauvignon at 25 °C of storage. The presence and sensitivity of Gram-positive and Gram-negative bacterial species Lactobacillus acidophilus, Lactobacillus crispatus, Lactobacillus salivarius, Acetobacter aceti, Acetobacter pasteurianus and Acetobacter orleaniensis were detected using Real time PCR.

  8. Isolation and identification of acetic acid bacteria and acid-producing property from Songhe Daqu%宋河大曲中醋酸菌的分离鉴定及产酸特性

    Institute of Scientific and Technical Information of China (English)

    侯小歌; 杜红阳; 李学思; 张咚咚; 李绍亮; 胡炳义

    2011-01-01

    对宋河大曲中的醋酸菌进行分离鉴定并研究耐酒精和产酸特性.共分离得到7株醋酸菌,经形态特征观察和生理生化试验,初步鉴定归2个属3个种,1株未知.2个属分别为葡糖杆菌属和醋杆菌属,3个种分别为氧化葡糖杆菌(Gluconobacter oxydans),巴氏醋杆菌(Acetobacter pasteurianus)和醋化醋杆菌(Acetobacter aceti).氧化葡糖杆菌和醋化醋杆菌是宋河大曲中的主要醋酸菌.醋杆菌在产酸过程中可耐受含量为5%vol~11%vol的酒精,氧化葡糖杆菌的产酸性能受含量为9%vol~11%vol酒精.醋杆菌和氧化葡糖杆菌产酸快,30℃培养20h后,可迅速产酸,44h后趋近稳定,最低pH值可达4.2以下.%Acetic acid bacteria from Songhe Daqu were isolated and identified, and the ability of tolerance to alcohol and acetic acid production were further studied.7 Acetic acid bacteria were isolated and identified as Gluconobacter oxydans, Acetobacter pasteurianus and Acetobacter aceti through morphological characteristics and physiological-biochemical characteristics except one unknown strain.G.oxydans and A.aceti are dominant acetic acid bacteria in Songhe Daqu.The ethanol tolerance of Acetobacter was in range from 5%-11% vol during acetic acidproduction, and that of G.oxydans was between 9%vol and 11%vol.Acetobacter and G.oxydans started to produce acetic acid rapidly after fermentation for 20 h and reached steady state after 44 h at 30℃.The minimum pH value was below 4.2.

  9. Microbial Diversity and Biochemical Analysis of Suanzhou: A Traditional Chinese Fermented Cereal Gruel

    Science.gov (United States)

    Qin, Huibin; Sun, Qinghui; Pan, Xuewei; Qiao, Zhijun; Yang, Hongjiang

    2016-01-01

    Suanzhou as a traditional Chinese gruel is fermented from proso millet and millet. The biochemical analysis showed Suanzhou had relatively high concentrations of lactic acid, acetic acid, and free amino acids. The metagenomics of Suanzhou were studied, with the analysis of the V4 region of 16S rRNA gene, the genera Lactobacillus and Acetobacter were found dominant with the average abundance of 58.2 and 24.4%, respectively; and with the analysis of the ITS1 region between 18S and 5.8S rRNA genes, 97.3% of the fungal community was found belonging to the genus Pichia and 2.7% belonging to five other genera. Moreover, the isolates recovered from 59 Suanzhou samples with various media were identified with the 16S rRNA or 18S rRNA gene analyses. Lactobacillus fermentum (26.9%), L. pentosus (19.4%), L. casei (17.9%), and L. brevis (16.4%) were the four dominant Lactobacillus species; Acetobacter lovaniensis (38.1%), A. syzygii (16.7%), A. okinawensis (16.7%), and A. indonesiensis (11.9%) were the four dominant Acetobacter species; and Pichia kudriavzevii (55.8%) and Galactomyces geotrichum (23.1%) were the two dominant fungal species. Additionally, L. pentosus p28-c and L. casei h28-c1 were selected for the fermentations mimicking the natural process. Collectively, our data demonstrate that Suanzhou is a nutritional food high in free amino acids and organic acids. Diverse Lactobacillus, Acetobacter, and yeast species are identified as the dominant microorganisms in Suanzhou. The isolated strains can be further characterized and used as starters for the industrial production of Suanzhou safely.

  10. Surface modification of cellulose materials : from wood pulps to artificial blood vessels

    OpenAIRE

    Ahrenstedt, Lage

    2007-01-01

    This thesis describes the improvement of two radically different cellulose materials, paper and artificial blood vessels, constructed from two diverse cellulose sources, wood pulp and Acetobacter xylinum. The improvement of both materials was possible due to the natural affinity of the hemicellulose xyloglucan for cellulose. Chemical and mechanical pulps were treated with xyloglucan in the wet-end prior to hand sheet formation or by spray application of dry hand sheets, loading a comparable a...

  11. Microbial Diversity and Biochemical Analysis of Suanzhou: A Traditional Chinese Fermented Cereal Gruel.

    Science.gov (United States)

    Qin, Huibin; Sun, Qinghui; Pan, Xuewei; Qiao, Zhijun; Yang, Hongjiang

    2016-01-01

    Suanzhou as a traditional Chinese gruel is fermented from proso millet and millet. The biochemical analysis showed Suanzhou had relatively high concentrations of lactic acid, acetic acid, and free amino acids. The metagenomics of Suanzhou were studied, with the analysis of the V4 region of 16S rRNA gene, the genera Lactobacillus and Acetobacter were found dominant with the average abundance of 58.2 and 24.4%, respectively; and with the analysis of the ITS1 region between 18S and 5.8S rRNA genes, 97.3% of the fungal community was found belonging to the genus Pichia and 2.7% belonging to five other genera. Moreover, the isolates recovered from 59 Suanzhou samples with various media were identified with the 16S rRNA or 18S rRNA gene analyses. Lactobacillus fermentum (26.9%), L. pentosus (19.4%), L. casei (17.9%), and L. brevis (16.4%) were the four dominant Lactobacillus species; Acetobacter lovaniensis (38.1%), A. syzygii (16.7%), A. okinawensis (16.7%), and A. indonesiensis (11.9%) were the four dominant Acetobacter species; and Pichia kudriavzevii (55.8%) and Galactomyces geotrichum (23.1%) were the two dominant fungal species. Additionally, L. pentosus p28-c and L. casei h28-c1 were selected for the fermentations mimicking the natural process. Collectively, our data demonstrate that Suanzhou is a nutritional food high in free amino acids and organic acids. Diverse Lactobacillus, Acetobacter, and yeast species are identified as the dominant microorganisms in Suanzhou. The isolated strains can be further characterized and used as starters for the industrial production of Suanzhou safely. PMID:27610102

  12. Bacterial Ecology of Fermented Cucumber Rising pH Spoilage as Determined by Non-Culture Based Methods

    Science.gov (United States)

    Medina, Eduardo; Pérez-Díaz, Ilenys M.; Breidt, Fred; Hayes, Janet; Franco, Wendy; Butz, Natasha; Azcarate-Peril, María Andrea

    2016-01-01

    Fermented cucumber spoilage (FCS) characterized by rising pH and the appearance of manure and cheese like aromas is a challenge of significant economical impact for the pickling industry. Previous culture based studies identified the yeasts Pichia manshurica and Issatchenkia occidentalis, four gram positive bacteria, Lactobacillus buchneri, Lactobacillus parrafaraginis, Clostridium sp. and Propionibacterium and one gram-negative genus, Pectinatus as relevant in various stages of FCS given their ability to metabolize lactic acid. It was the objective of this study to augment the current knowledge of FCS using culture independent methods to microbiologically characterize commercial spoilage samples. Ion Torrent data and 16S rRNA cloning library analyses of samples collected from commercial fermentation tanks confirmed the presence of L. rapi and L. buchneri and revealed the presence of additional species involved in the development of FCS such as Lactobacillus namurensis, Lactobacillus acetotolerans, Lactobacillus panis, Acetobacter peroxydans, Acetobacter aceti, and Acetobacter pasteurianus at pH below 3.4. The culture independent analyses also revealed the presence of species of Veillonella and Dialister in spoilage samples with pH above 4.0 and confirmed the presence of Pectinatus spp. during lactic acid degradation at the higher pH. Acetobacter spp. were successfully isolated from commercial samples collected from tanks subjected to air purging by plating on Mannitol Yeast Peptone agar. In contrast, Lactobacillus spp. were primarily identified in samples of FCS collected from tanks not subjected to air purging for more than 4 months. Thus, it is speculated that oxygen availability may be a determining factor in the initiation of spoilage and the leading microbiota. Practical Application Understanding of the underlying microbiology and biochemistry driving FCS is essential to enhancing the sodium chloride (NaCl)-free cucumber fermentation technology and in

  13. Microbial Diversity and Biochemical Analysis of Suanzhou: A Traditional Chinese Fermented Cereal Gruel.

    Science.gov (United States)

    Qin, Huibin; Sun, Qinghui; Pan, Xuewei; Qiao, Zhijun; Yang, Hongjiang

    2016-01-01

    Suanzhou as a traditional Chinese gruel is fermented from proso millet and millet. The biochemical analysis showed Suanzhou had relatively high concentrations of lactic acid, acetic acid, and free amino acids. The metagenomics of Suanzhou were studied, with the analysis of the V4 region of 16S rRNA gene, the genera Lactobacillus and Acetobacter were found dominant with the average abundance of 58.2 and 24.4%, respectively; and with the analysis of the ITS1 region between 18S and 5.8S rRNA genes, 97.3% of the fungal community was found belonging to the genus Pichia and 2.7% belonging to five other genera. Moreover, the isolates recovered from 59 Suanzhou samples with various media were identified with the 16S rRNA or 18S rRNA gene analyses. Lactobacillus fermentum (26.9%), L. pentosus (19.4%), L. casei (17.9%), and L. brevis (16.4%) were the four dominant Lactobacillus species; Acetobacter lovaniensis (38.1%), A. syzygii (16.7%), A. okinawensis (16.7%), and A. indonesiensis (11.9%) were the four dominant Acetobacter species; and Pichia kudriavzevii (55.8%) and Galactomyces geotrichum (23.1%) were the two dominant fungal species. Additionally, L. pentosus p28-c and L. casei h28-c1 were selected for the fermentations mimicking the natural process. Collectively, our data demonstrate that Suanzhou is a nutritional food high in free amino acids and organic acids. Diverse Lactobacillus, Acetobacter, and yeast species are identified as the dominant microorganisms in Suanzhou. The isolated strains can be further characterized and used as starters for the industrial production of Suanzhou safely.

  14. Self-supported silver nanoparticles containing bacterial cellulose membranes

    Energy Technology Data Exchange (ETDEWEB)

    Barud, Hernane S.; Barrios, Celina; Regiani, Thais; Marques, Rodrigo F.C. [Institute of Chemistry-UNESP, CP 355, Zip 14801-970, Araraquara, SP, 14801-970 (Brazil); Verelst, Marc; Dexpert-Ghys, Jeannette [Centre d' Elaboration de Materiaux et d' Etudes Structurales, CEMES, UPR No. 8011 - Universite Toulouse III, B.P. 94347, 29 rue Jeanne Marvig, 31055 Toulouse Cedex (France); Messaddeq, Younes [Institute of Chemistry-UNESP, CP 355, Zip 14801-970, Araraquara, SP, 14801-970 (Brazil); Ribeiro, Sidney J.L. [Institute of Chemistry-UNESP, CP 355, Zip 14801-970, Araraquara, SP, 14801-970 (Brazil)], E-mail: sidney@iq.unesp.br

    2008-05-01

    Hydrated bacterial cellulose (BC) membranes obtained from cultures of Acetobacter xylinum were used in the preparation of silver nanoparticles containing cellulose membranes. In situ preparation of Ag nanoparticles was achieved from the hydrolytic decomposition of silver triethanolamine (TEA) complexes. Scanning electron microscopy (SEM) images and X-ray diffraction (XRD) patterns both lead to the observation of spherical metallic silver particles with mean diameter of 8 nm well adsorbed onto the BC fibriles.

  15. Study on the production of bacterial cellulose by tea fermentation%茶水发酵法生产细菌纤维素的研究

    Institute of Scientific and Technical Information of China (English)

    邱晓红; 周炳全

    2006-01-01

    主要介绍了以茶水、白砂糖为原料,利用木醋杆菌(Acetobacter xylinum)发酵生产细菌纤维素的工艺流程,为细菌纤维素的大规模生产开发出了成本低、来源广泛的原料.

  16. Fermentation Tecniques and Applications of Bacterial Cellulose: a Review Técnicas de fermentación y aplicaciones de la celulosa bacteriana: una revisión

    Directory of Open Access Journals (Sweden)

    Luz Dary Carreño Pineda

    2012-12-01

    Full Text Available Bacterial cellulose is a polymer obtained by fermentation with microorganismsfrom Acetobacter, Rhizobium, Agrobacterium and Sarcina genera. Amongthem, Acetobacter xylinum is the most efficient specie. This polymer hasthe same chemical composition of plant cellulose, but its conformation andphysicochemical properties are different, making it attractive for several applications, especially in the areas of food, separation processes, catalysis andhealth, due to its biocompatibility. However, the main problem is the production in mass that is constrained by low yield. It is therefore necessaryto develop some alternatives. This paper presents a review about synthesis,production, properties and principal applications of bacterial cellulose, as wellas some alternatives to reduce the difficulties for process scaling.La celulosa bacteriana es un polímero obtenido por fermentación con microrganismosde los géneros Acetobacter, Rhizobium, Agrobacterium y Sarcina, delas cuales la especie más eficiente es la Acetobacter Xylinum. Este polímero presenta la misma estructura química de la celulosa de origen vegetal, pero difiereen su conformación y propiedades fisicoquímicas, lo que lo hace atractivo para diversas aplicaciones, especialmente en las áreas de alimentos, procesosde separación, catálisis y en medicina, gracias a su biocompatibilidad. Sin embargo, el principal problema es la producción a gran escala limitada por losbajos rendimientos, lo que genera la necesidad de desarrollar alternativas que permitan disminuir o eliminar las causas de esta limitación. En este artículo se hace una revisión acerca de la síntesis, producción, propiedades y principales aplicaciones de la celulosa bacteriana, así como de algunas alternativas estudiadas para disminuir los inconvenientes en el escalamiento del proceso.

  17. Biochemical localization of a protein involved in Gluconacetobacter hansenii cellulose synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Iyer, Prashanti R; Catchmark, Jeffrey M; Brown, Nicole Robitaille; Tien, Ming

    2011-02-08

    Using subcellular fractionation and Western blot methods, we have shown that AcsD, one of the proteins encoded by the Acetobacter cellulose synthase (acs) operon, is localized in the periplasmic region of the cell. AcsD protein was heterologously expressed in Escherichia coli and purified using histidine tag affinity methods. The purified protein was used to obtain rabbit polyclonal antibodies. The purity of the subcellular fractions was assessed by marker enzyme assays.

  18. Production of alcohol and acetic acid from pineapple wastes in Thailand

    Energy Technology Data Exchange (ETDEWEB)

    Muttamara, S.; Nirmala, D.J.

    1982-01-01

    Pineapple cannery wastes were supplemented with (NH/sub 4/)/sub 2/SO/sub 4/ and KH/sub 2/PO/sub 4/ and fermented with Saccharomyces cerevisiae to produce ethanol. The liquid portion of the fermentation broth was inoculated with Acetobacter aceti to produce acetic acid. Maximum yields of ethanol and acetic acid were 5.8% and 1.9%, respectively. The solid residue had feed value.

  19. Bacterial Ecology of Fermented Cucumber Rising pH Spoilage as Determined by Nonculture-Based Methods.

    Science.gov (United States)

    Medina, Eduardo; Pérez-Díaz, Ilenys M; Breidt, Fred; Hayes, Janet; Franco, Wendy; Butz, Natasha; Azcarate-Peril, María Andrea

    2016-01-01

    Fermented cucumber spoilage (FCS) characterized by rising pH and the appearance of manure- and cheese-like aromas is a challenge of significant economical impact for the pickling industry. Previous culture-based studies identified the yeasts Pichia manshurica and Issatchenkia occidentalis, 4 Gram-positive bacteria, Lactobacillus buchneri, Lactobacillus parrafaraginis, Clostridium sp., and Propionibacterium and 1 Gram-negative genus, Pectinatus, as relevant in various stages of FCS given their ability to metabolize lactic acid. It was the objective of this study to augment the current knowledge of FCS using culture-independent methods to microbiologically characterize commercial spoilage samples. Ion Torrent data and 16S rRNA cloning library analyses of samples collected from commercial fermentation tanks confirmed the presence of L. rapi and L. buchneri and revealed the presence of additional species involved in the development of FCS such as Lactobacillus namurensis, Lactobacillus acetotolerans, Lactobacillus panis, Acetobacter peroxydans, Acetobacter aceti, and Acetobacter pasteurianus at pH below 3.4. The culture-independent analyses also revealed the presence of species of Veillonella and Dialister in spoilage samples with pH above 4.0 and confirmed the presence of Pectinatus spp. during lactic acid degradation at the higher pH. Acetobacter spp. were successfully isolated from commercial samples collected from tanks subjected to air purging by plating on Mannitol Yeast Peptone agar. In contrast, Lactobacillus spp. were primarily identified in samples of FCS collected from tanks not subjected to air purging for more than 4 mo. Thus, it is speculated that oxygen availability may be a determining factor in the initiation of spoilage and the leading microbiota. PMID:26605993

  20. Acetic Acid Production by an Electrodialysis Fermentation Method with a Computerized Control System

    OpenAIRE

    Nomura, Yoshiyuki; Iwahara, Masayoshi; Hongo, Motoyoshi

    1988-01-01

    In acetic acid fermentation by Acetobacter aceti, the acetic acid produced inhibits the production of acetic acid by this microorganism. To alleviate this inhibitory effect, we developed an electrodialysis fermentation method such that acetic acid is continuously removed from the broth. The fermentation unit has a computerized system for the control of the pH and the concentration of ethanol in the fermentation broth. The electrodialysis fermentation system resulted in improved cell growth an...

  1. Microbial Diversity and Biochemical Analysis of Suanzhou: A Traditional Chinese Fermented Cereal Gruel

    Science.gov (United States)

    Qin, Huibin; Sun, Qinghui; Pan, Xuewei; Qiao, Zhijun; Yang, Hongjiang

    2016-01-01

    Suanzhou as a traditional Chinese gruel is fermented from proso millet and millet. The biochemical analysis showed Suanzhou had relatively high concentrations of lactic acid, acetic acid, and free amino acids. The metagenomics of Suanzhou were studied, with the analysis of the V4 region of 16S rRNA gene, the genera Lactobacillus and Acetobacter were found dominant with the average abundance of 58.2 and 24.4%, respectively; and with the analysis of the ITS1 region between 18S and 5.8S rRNA genes, 97.3% of the fungal community was found belonging to the genus Pichia and 2.7% belonging to five other genera. Moreover, the isolates recovered from 59 Suanzhou samples with various media were identified with the 16S rRNA or 18S rRNA gene analyses. Lactobacillus fermentum (26.9%), L. pentosus (19.4%), L. casei (17.9%), and L. brevis (16.4%) were the four dominant Lactobacillus species; Acetobacter lovaniensis (38.1%), A. syzygii (16.7%), A. okinawensis (16.7%), and A. indonesiensis (11.9%) were the four dominant Acetobacter species; and Pichia kudriavzevii (55.8%) and Galactomyces geotrichum (23.1%) were the two dominant fungal species. Additionally, L. pentosus p28-c and L. casei h28-c1 were selected for the fermentations mimicking the natural process. Collectively, our data demonstrate that Suanzhou is a nutritional food high in free amino acids and organic acids. Diverse Lactobacillus, Acetobacter, and yeast species are identified as the dominant microorganisms in Suanzhou. The isolated strains can be further characterized and used as starters for the industrial production of Suanzhou safely. PMID:27610102

  2. Bacterial Ecology of Fermented Cucumber Rising pH Spoilage as Determined by Nonculture-Based Methods.

    Science.gov (United States)

    Medina, Eduardo; Pérez-Díaz, Ilenys M; Breidt, Fred; Hayes, Janet; Franco, Wendy; Butz, Natasha; Azcarate-Peril, María Andrea

    2016-01-01

    Fermented cucumber spoilage (FCS) characterized by rising pH and the appearance of manure- and cheese-like aromas is a challenge of significant economical impact for the pickling industry. Previous culture-based studies identified the yeasts Pichia manshurica and Issatchenkia occidentalis, 4 Gram-positive bacteria, Lactobacillus buchneri, Lactobacillus parrafaraginis, Clostridium sp., and Propionibacterium and 1 Gram-negative genus, Pectinatus, as relevant in various stages of FCS given their ability to metabolize lactic acid. It was the objective of this study to augment the current knowledge of FCS using culture-independent methods to microbiologically characterize commercial spoilage samples. Ion Torrent data and 16S rRNA cloning library analyses of samples collected from commercial fermentation tanks confirmed the presence of L. rapi and L. buchneri and revealed the presence of additional species involved in the development of FCS such as Lactobacillus namurensis, Lactobacillus acetotolerans, Lactobacillus panis, Acetobacter peroxydans, Acetobacter aceti, and Acetobacter pasteurianus at pH below 3.4. The culture-independent analyses also revealed the presence of species of Veillonella and Dialister in spoilage samples with pH above 4.0 and confirmed the presence of Pectinatus spp. during lactic acid degradation at the higher pH. Acetobacter spp. were successfully isolated from commercial samples collected from tanks subjected to air purging by plating on Mannitol Yeast Peptone agar. In contrast, Lactobacillus spp. were primarily identified in samples of FCS collected from tanks not subjected to air purging for more than 4 mo. Thus, it is speculated that oxygen availability may be a determining factor in the initiation of spoilage and the leading microbiota.

  3. Biosynthesis and Characterization of Nanocellulose-Gelatin Films

    OpenAIRE

    Muenduen Phisalaphong; Pongpun Siripong; Sutasinee Seetabhawang; Siriporn Taokaew

    2013-01-01

    A nanocellulose-gelatin (bacterial cellulose gelatin (BCG)) film was developed by a supplement of gelatin, at a concentration of 1%–10% w/v, in a coconut-water medium under the static cultivation of Acetobacter xylinum. The two polymers exhibited a certain degree of miscibility. The BCG film displayed dense and uniform homogeneous structures. The Fourier transform infrared spectroscopy (FTIR) results demonstrated interactions between the cellulose and gelatin. Incorporation of gelatin into a ...

  4. Bacterial Cellulose Membranes Used as Artificial Substitutes for Dural Defection in Rabbits

    OpenAIRE

    Chen Xu; Xia Ma; Shiwen Chen; Meifeng Tao; Lutao Yuan; Yao Jing

    2014-01-01

    To improve the efficacy and safety of dural repair in neurosurgical procedures, a new dural material derived from bacterial cellulose (BC) was evaluated in a rabbit model with dural defects. We prepared artificial dura mater using bacterial cellulose which was incubated and fermented from Acetobacter xylinum. The dural defects of the rabbit model were repaired with BC membranes. All surgeries were performed under sodium pentobarbital anesthesia, and all efforts were made to minimize suffering...

  5. Bacterial Cellulose From Rice Waste Water With Addition Chitosan, Glycerol, And Silver Nanoparticle

    OpenAIRE

    Eli Rohaeti; Endang WLFX; Anna Rakhmawati

    2016-01-01

    This study aimed to prepare silver nanoparticles chemically, deposite silver nanoparticles on bacterial cellulose-chitosan-glycerol composite based rice waste water, as well as test the antibacterial activity of bacterial cellulose and its composite. Preparation of silver nanoparticles was conducted by chemical reduction of silver nitrate solution, as well as trisodium citrate as the reductor. Bacterial cellulose from rice waste water is fermented by the bacteria Acetobacter xylinum for 7 day...

  6. 15-2-4 : セルロース生産微生物による機能性セルロースの創製 : セルロース合成における高次構造制御

    OpenAIRE

    天野, 良彦; 神田, 鷹久

    2005-01-01

    Cerboxymethylcellulose (CMC) degrading activity and various sugars in addition to cellulose were detected in the culture broth after one day culture of Acetobacter xlinum. Cellulose morphology changed as it was cultured in the presence of oligosaccharides such as gentiobiose and cellobiose. It is confirmed that cellulose structures such as the width of microfibril and cellulose ribbon, the crystallinity, and the ratio of Ia and Ib were different from native bacterial cellulose when it was cul...

  7. Alteration of in vivo cellulose ribbon assembly by carboxymethylcellulose and other cellulose derivatives

    OpenAIRE

    1982-01-01

    In vivo cellulose ribbon assembly by the Gram-negative bacterium Acetobacter xylinum can be altered by incubation in carboxymethylcellulose (CMC), a negatively charged water-soluble cellulose derivative, and also by incubation in a variety of neutral, water-soluble cellulose derivatives. In the presence of all of these substituted celluloses, normal fasciation of microfibril bundles to form the typical twisting ribbon is prevented. Alteration of ribbon assembly is most extensive in the presen...

  8. 15-2-4 :セルロース生産微生物による機能性セルロースの創製; セルロース合成における高次構造制御

    OpenAIRE

    天野, 良彦; 神田, 鷹久

    2004-01-01

    We tried to investigated various carbohydrates and cellulose degrading enzyme activityin the culture broth of cellulose producing microorganism, Acetobacter xylinum to clarify, the role of cellulase for cellulose production. Cerboxymethylcellulose (CMC) degrading activity and various sugars in addition to cellulose were detected in the culture broth after one day culture. These sugars increased gradually and were identified to some kinds of β-linked disaccharides such as gentiobiose and cello...

  9. Pembuatan Membran Selulosa Bakteri Coating Kitosan - Kolagen Untuk Aplikasi Gtr ( Guide Tissue Regeneration ) Sebagai Pembalut Luka Pada Mencit (Mus Musculus)Secara In Vivo

    OpenAIRE

    Humaira, Nadia Maulida

    2015-01-01

    Bacterial cellulose produced from the fermentation process used in the development of Acetobacter xylinum to increase efficiency of bacterial cellulose one of them in the biomedical field , is membrane . This study aimed to determine the effect concentration of chitosan-collagen, see optimum characterization of bacterial cellulose membrane coating of chitosan-collagen that can be used in the application as wound dressings in mice by In Vivo. Preparation of the bacterial cellulose membrane usi...

  10. Molecular identification and physiological characterization of yeasts, lactic acid bacteria and acetic acid bacteria isolated from heap and box cocoa bean fermentations in West Africa.

    Science.gov (United States)

    Visintin, Simonetta; Alessandria, Valentina; Valente, Antonio; Dolci, Paola; Cocolin, Luca

    2016-01-01

    Yeast, lactic acid bacteria (LAB) and acetic acid bacteria (AAB) populations, isolated from cocoa bean heap and box fermentations in West Africa, have been investigated. The fermentation dynamicswere determined by viable counts, and 106 yeasts, 105 LAB and 82 AAB isolateswere identified by means of rep-PCR grouping and sequencing of the rRNA genes. During the box fermentations, the most abundant species were Saccharomyces cerevisiae, Candida ethanolica, Lactobacillus fermentum, Lactobacillus plantarum, Acetobacter pasteurianus and Acetobacter syzygii, while S. cerevisiae, Schizosaccharomyces pombe, Hanseniaspora guilliermondii, Pichia manshurica, C. ethanolica, Hanseniaspora uvarum, Lb. fermentum, Lb. plantarum, A. pasteurianus and Acetobacter lovaniensis were identified in the heap fermentations. Furthermore, the most abundant species were molecularly characterized by analyzing the rep-PCR profiles. Strains grouped according to the type of fermentations and their progression during the transformation process were also highlighted. The yeast, LAB and AAB isolates were physiologically characterized to determine their ability to grow at different temperatures, as well as at different pH, and ethanol concentrations, tolerance to osmotic stress, and lactic acid and acetic acid inhibition. Temperatures of 45 °C, a pH of 2.5 to 3.5, 12% (v/v) ethanol and high concentrations of lactic and acetic acid have a significant influence on the growth of yeasts, LAB and AAB. Finally, the yeastswere screened for enzymatic activity, and the S. cerevisiae, H. guilliermondii, H. uvarumand C. ethanolica species were shown to possess several enzymes that may impact the quality of the final product.

  11. 高效催化合成3-羟基丙酸的菌株特性%Characterization of a strain catalyzing biosynthesis of 3-hydroxypropionic acid

    Institute of Scientific and Technical Information of China (English)

    吴金鑫; 宗红; 陆信曜; 诸葛斌; 方慧英; 宋健

    2014-01-01

    3-羟基丙酸(3-HP)是一种具有重要经济价值的新兴平台化合物,可用来合成多种化工产品和特种生物降解材料.本研究以1,3-丙二醇(1,3-PDO)为底物全细胞催化合成3-HP.通过菌株筛选和ESI-MS验证共得到3株目的微生物,经鉴定比较,Acetobacter sp.催化合成3-HP性能最高,10gL-1 1,3-PDO经7h可生成11.65 g L-1的3-HP,摩尔转化率高达98.4%.对Acetobacter sp.底物催化特异性研究表明该菌株对其他相关醇类如乙二醇、戊醇、苯甲醇、苯乙醇等具有不同程度的催化能力,Acetobacter sp.对甘油仅具有微弱催化活性.研究表明Ca2+、Mg2+、Fe3+能够显著提高细胞催化合成3-HP的速率,向全细胞催化液中加入终浓度0.01 mol L-1的CaCl2,细胞催化活性提高了11.6%.同时考察了氧载体和表面活性剂、贮存温度、菌体重复利用对Acetobacter sp催化活性的影响并获得了该菌株催化合成3-HP的特性.利用Acetobacter sp.细胞催化1,3-PDO,为3-HP的制备提供了一种新的可能.

  12. 杏皮渣醋酸发酵醋酸菌的分离筛选和鉴定%Isolation and Identification of Acetic Acid Bacteria for Fermentation of Brewing Vinegar from Apricot Dreg

    Institute of Scientific and Technical Information of China (English)

    吴越; 张富县; 艾乃吐拉·马合木提; 傅力

    2013-01-01

    [目的]筛选获得适宜杏皮渣醋发酵的醋酸菌并对其进行鉴定,为杏皮渣醋质量及产量的提高奠定基础.[方法]在杏皮渣汁自然发酵液、固态发酵醋醅和杏园的土壤中分离醋酸菌,对分离菌株进行产酸曲线的测定及生理生化鉴定,对产酸量高的菌株进行16S rDNA序列测定并建立系统发育树,对其进行鉴定.[结果]共分离得到6株菌,其中Ac01、Ac02、Cp01、Cp02和Tr01属于醋酸菌属.初步判定,在杏皮渣汁的自然发酵液中分离的Ac01和Ac02可能属于醋化醋杆菌(Acetobacter aceti),菌株Ac02醋酸产量在分离菌株中最高,可达到3.04 g/100 mL,其16S rDNA序列与Acetobacter pomorum strain LMG 18848 16S rDNA序列相似度大于99%.[结论]在杏皮渣汁自然发酵液中分离得到的菌株Ac02为醋杆菌属(Acaobacter)的Acetobacter pomorum strain LMG 18848,是一株在杏皮渣醋生产中有应用潜力的醋酸菌.%[Objective] The aim of this study was to screen and identify the acetic acid bacteria strain for brewing vinegar from apricot dregs and lay the foundation for the improvement of the quality and yield of apricot dregs vinegar.[Method] The acetic acid bacteria were isolated from the natural fermentation broth of apricot dregs juice,the solid fermentative substrate of vinegar and the orchard soil,the curve of acid production was measured and the experiments of biochemical identification of each selected strain were conducted.The strains which could produce the highest acid were identified by 16S rDNA sequence and by the phylogenetic tree.[Result] Six strains were isolated,Ac01,Ac02,Cp01,Cp02 and Tr01 were identified as Acetobacter.Ac01 and Ac02 separated from the natural fermentation broth of apricot dregs juice may belong to Acetobacter aceti after the preliminary determination,the acetic acid yield of the strain Ac02 can reach 3.04 g/100 mL.The similarity of 16S rDNA sequence is more than 99% between Ac02 and Acetobacter pomorum strain

  13. Study of pineapple peelings processing into vinegar by biotechnology.

    Science.gov (United States)

    Sossou, Seyram K; Ameyapoh, Yaovi; Karou, Simplice D; de Souza, Comlan

    2009-06-01

    This study aimed to reduce post-harvest losses of pineapple local variety egbenana by the transformation of juice into vinegar through biotechnological process. Vinegar was produced through two successive fermentations: alcoholic and acetic fermentations. The alcohol fermentation was carried out at 30 degrees C using yeast. Biomass, pH and Brix were evaluated daily during the fermentation. Acetic fermentation was carried out at 30 degrees C using an acetic bacteria strain isolated from pineapple wine previously exposed to ambient temperature (28 degrees C) for 5 days. Biomass, pH and acid levels were monitored each 2 days. The performance of acetic bacteria isolated was also assessed by studying their glucose and ethanol tolerance. The study allowed the isolation of yeast coded Saccharomyces cerevisiae (LAS01) and an acetic bacteria coded Acetobacter sp. (ASV03) both occurring in the pineapple juice. The monitoring of successive fermentations indicated that the pineapple juice with sugar concentration of 20 Brix, seeded with 10(6) cells of Saccharomyces cerevisiae (LAS01) for alcoholic fermentation for 4 days and afterwards seeded with 10(6) cells of Acetobacter sp. resulted in 4.5 acetic degree vinegar at Brix 5.3% and pH 2.8 for 23 to 25 days. The study of glucose tolerance of the strain of Acetobacter sp. showed that the growth of acetic bacteria was important in a juice with high concentration of sugar. However, the concentration of ethanol did not effect on the acetic bacteria growth. These results enabled on one hand to improve the manufacturing technology of vinegar from fruits and on the other hand to produce a starter of yeast and acetic bacteria strains for this production. PMID:19803120

  14. Detailed analyses of the bacterial populations in processed cocoa beans of different geographic origin, subject to varied fermentation conditions.

    Science.gov (United States)

    Bortolini, Cristian; Patrone, Vania; Puglisi, Edoardo; Morelli, Lorenzo

    2016-11-01

    The quality of chocolate is influenced by several parameters, one of which is bacterial diversity during fermentation and drying; a crucial factor for the generation of the optimal cocoa flavor precursors. Our understanding of the bacterial populations involved in chocolate fermentation can be improved by the use of high-throughput sequencing technologies (HTS), combined with PCR amplification of the 16S rRNA subunit. Here, we have conducted a high-throughput assessment of bacterial diversity in four processed samples of cocoa beans from different geographic origins. As part of this study, we also assessed whether different DNA extraction methods could affect the quality of our data. The dynamics of microbial populations were analyzed postharvest (fermentation and sun drying) and shipment, before entry to the industrial process. A total of 691,867 high quality sequences were obtained by Illumina MiSeq sequencing of the two bacterial 16S rRNA hypervariable regions, V3 and V4, following paired-read assembly of the raw reads. Manual curation of the 16S database allowed us to assign the correct taxonomic classifications, at species level, for 83.8% of those reads. This approach revealed a limited biodiversity and population dynamics for both the lactic acid bacteria (LAB) and acetic acid bacteria (AAB), both of which are key players during the acetification and lactic acid fermentation phases. Among the LAB, the most abundant species were Lactobacillus fermentum, Enterococcus casseliflavus, Weissella paramesenteroides, and Lactobacillus plantarum/paraplantarum. Among the AAB, Acetobacter syzygii, was most abundant, then Acetobacter senegalensis and Acetobacter pasteriuanus. Our results indicate that HTS approach has the ability to provide a comprehensive view of the cocoa bean microbiota at the species level. PMID:27458718

  15. The microbial diversity of water kefir.

    Science.gov (United States)

    Gulitz, Anna; Stadie, Jasmin; Wenning, Mareike; Ehrmann, Matthias A; Vogel, Rudi F

    2011-12-15

    The microbial diversity of water kefir, made from a mixture of water, dried figs, a slice of lemon and sucrose was studied. The microbial consortia residing in the granules of three water kefirs of different origins were analyzed. A collection of 453 bacterial isolates was obtained on different selective/differential media. Bacterial isolates were grouped with randomly amplified polymorphic DNA (RAPD)-PCR analyses. One representative of each RAPD genotype was identified by comparative 16S rDNA gene sequencing. The predominant genus in water kefirs I and II was Lactobacillus, which accounted for 82.1% in water kefir I and 72.1% in water kefir II of the bacterial isolates. The most abundant species in water kefirs I and II were Lactobacillus hordei and Lb. nagelii followed by considerably lower numbers of Lb. casei. Other lactic acid bacteria (LAB) were identified as Leuconostoc mesenteroides and Lc. citreum in all three water kefirs. The most abundant species in water kefir III was Lc. mesenteroides (28%) and Lc. citreum (24.3%). A total of 57 LAB belonging to the species of Lb. casei, Lb. hordei, Lb. nagelii, Lb. hilgardii and Lc. mesenteroides were able to produce exopolysacchrides from sucrose. Non LABs were identified as Acetobacter fabarum and Ac. orientalis. The Acetobacter species were more prevalent in consortium III. Cluster analyses of RAPD-PCR patterns revealed an interspecies diversity among the Lactobacillus and Acetobacter strains. Aditionally, Saccharomyces cerevisiae, Lachancea fermentati, Hanseniaospora valbyensis and Zygotorulaspora florentina were isolated and identified by comparison of partial 26S rDNA sequences and FTIR spectroscopy. PMID:22000549

  16. Isolation, characterization and optimization of indigenous acetic acid bacteria and evaluation of their preservation methods

    Directory of Open Access Journals (Sweden)

    K Beheshti-Maal

    2010-06-01

    Full Text Available Background and Objectives: Acetic acid bacteria (AAB are useful in industrial production of vinegar. The present study aims at isolation and identification of acetic acid bacteria with characterization, optimization, and evaluation of their acetic acid productivity."nMaterials and Methods: Samples from various fruits were screened for presence of acetic acid bacteria on glucose, yeast extract, calcium carbonate (GYC medium. Carr medium supplemented with bromocresol green was used for distinguishing Acetobacter from Gluconobacter. The isolates were cultured in basal medium to find the highest acetic acid producer. Biochemical tests followed by 16S rRNA and restriction analyses were employed for identification of the isolate and phylogenic tree was constructed. Bacterial growth and acid production conditions were optimized based on optimal inoculum size, pH, temperature, agitation, aeration and medium composition."nResults: Thirty-seven acetic acid bacteria from acetobacter and gluconobacter members were isolated. Acetic acid productivity yielded 4 isolates that produced higher amounts of acid. The highest producer of acid (10.03% was selected for identification. The sequencing and restriction analyses of 16S rRNA revealed a divergent strain of Acetobacter pasteurianus (Gene bank accession number # GU059865. The optimum condition for acid production was a medium composed of 2% glucose, 2% yeast extract, 3% ethanol and 3% acid acetic at inoculum size of 4% at 3L/Min aeration level in the production medium. The isolate was best preserved in GYC medium at 12oC for more than a month. Longer preservation was possible at -70oC."nConclusion: The results are suggestive of isolation of an indigenous acetic acid bacteria. Pilot plan is suggested to study applicability of the isolated strain in acetic acid production.

  17. Microbial Diversity and Biochemical Analysis of Suanzhou: A Traditional Chinese Fermented Cereal Gruel

    Directory of Open Access Journals (Sweden)

    Huibin Qin

    2016-08-01

    Full Text Available Suanzhou as a traditional Chinese gruel is fermented from proso millet and millet. The biochemical analysis showed Suanzhou had relatively high concentrations of lactic acid, acetic acid, and free amino acids. The metagenomics of Suanzhou were studied, with the analysis of the V4 region of 16S rRNA gene, the genera Lactobacillus and Acetobacter were found dominant with the average abundance of 58.2% and 24.4%, respectively; and with the analysis of the ITS1 region between 18S and 5.8S rRNA genes, 97.3% of the fungal community was found belonging to the genus Pichia and 2.7% belonging to 5 other genera. Moreover, the isolates recovered from 59 Suanzhou samples with various media were identified with the 16S rRNA or 18S rRNA gene analyses. L. fermentum (26.9%, L. pentosus (19.4%, L. casei (17.9%, and L. brevis (16.4% were the four dominant Lactobacillus species; A. lovaniensis (38.1%, A. syzygii (16.7%, A. okinawensis (16.7%, and A. indonesiensis (11.9% were the four dominant Acetobacter species; and Pichia kudriavzevii (55.8% and Galactomyces geotrichum (23.1% were the two dominant fungal species. Additionally, L. pentosus p28-c and L. casei h28-c1 were selected for the fermentations mimicking the natural process. Collectively, our data demonstrate that Suanzhou is a nutritional food high in free amino acids and organic acids. Diverse Lactobacillus, Acetobacter, and yeast species are identified as the dominant microorganisms in Suanzhou. The isolated strains can be further characterized and used as starters for the industrial production of Suanzhou safely.

  18. Production of bacterial cellulose from alternate feedstocks

    Energy Technology Data Exchange (ETDEWEB)

    D. N. Thompson; M. A. Hamilton

    2000-05-07

    Production of bacterial cellulose by Acetobacter xylinum ATCC 10821 and 23770 in static cultures was tested from unamended food process effluents. Effluents included low- and high-solids potato effluents (LS and HS), cheese whey permeate (CW), and sugar beet raffinate (CSB). Strain 23770 produced 10% less cellulose from glucose than did 10821, and diverted more glucose to gluconate. Unamended HS, CW, and CSB were unsuitable for cellulose production by either strain, while LS was unsuitable for production by 10821. However, 23770 produced 17% more cellulose from LS than from glucose, indicating unamended LS could serve as a feedstock for bacterial cellulose.

  19. Production of Bacterial Cellulose from Alternate Feedstocks

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, David Neil; Hamilton, Melinda Ann

    2000-05-01

    Production of bacterial cellulose by Acetobacter xylinum ATCC 10821 and 23770 in static cultures was tested from unamended food process effluents. Effluents included low- and high-solids potato effluents (LS & HS), cheese whey permeate (CW), and sugar beet raffinate (CSB). Strain 23770 produced 10% less cellulose from glucose than did 10821, and diverted more glucose to gluconate. Unamended HS, CW, and CSB were unsuitable for cellulose production by either strain, while LS was unsuitable for production by 10821. However, 23770 produced 17% more cellulose from LS than from glucose, indicating unamended LS could serve as a feedstock for bacterial cellulose.

  20. Chemical Composition and Biological Activities of Essential Oil from the Rhizomes of Iris bulleyana

    Institute of Scientific and Technical Information of China (English)

    DENG Guo-bin; ZHANG Han-bo; XUE Hong-fen; CHEN Shan-na; CHEN Xiao-lan

    2009-01-01

    Iris bulleyana has long been used as a remedy for detoxication and detumescence.Hydrodistillation was used to extract the essential oil from its rhizomes,and 0.23% oil yield was obtained.Using gas chromatography-mass spectrometry (GCMS) analysis,31 chemicals including aristolone,euparene,β-gurjunene,δ-amorphene,α-muurolene,α-cadinol,camphor,γ-elemene,and τ-eadinol were identified.The essential oil exhibited antibacterial activity against Acetobacter calcoacetica,Bacillus subtillis,Clostridium sporogenes,Clostridium perfringens,Escherichia coli,Salmonella typhii,Staphylococcus aureus,and Yersinia enterocolitica.Its antifungal and antioxidant activities were also tested.

  1. Study on the Isolation and Identifiation of Microbes of Kombucha%红茶菌混合菌种的分离与鉴定

    Institute of Scientific and Technical Information of China (English)

    吴薇; 盖宝川; 籍保平

    2004-01-01

    本文对来自北京的某个红茶菌进行了菌种分离和鉴定,作者从该红茶菌中分离得到了五个菌种,经鉴定分别为巴斯德酵母(Saccharomyces pastorianus Hansen)、粟酒裂殖酵母(Schizosaccharomyces pombe Lindner)、醋化醋杆菌木质亚种(Acetobacter xylinum)、甲醇酸单胞菌(Acidomonas methanolica)、乳杆菌科乳杆菌属(Lactobacillus).

  2. 细菌纤维素发酵培养基的优化%Optimization of Medium for Fermentation Process of Bacterial Cellulose

    Institute of Scientific and Technical Information of China (English)

    欧竑宇; 贾士儒; 马霞

    2003-01-01

    采用Plackett-Burman设计法、响应面分析和最速增长途径法,对Acetobacter xylinum X-2静态发酵培养基进行了优化.在确定初始浓度远离最优水平后,寻求到最优区域.发酵培养基在最优区域时,A.xylinum X-2细菌纤维素的产量达到4.6 g/L,比其初始区域的结果提高1倍.

  3. Cellulose for medical applications: Past, present, and future

    Directory of Open Access Journals (Sweden)

    Hoenich, N.

    2006-11-01

    Full Text Available Films and tubes manufactured from cellulose have historically been used in the treatment of renal failure, but their use for this purpose has declined in recent years in favour of films manufactured from synthetic material blends. As the clinical application of cellulose for dialysis declines, new applications for its use are emerging, of which the most promising appears to be the use of microbial cellulose synthesized by Acetobacter xylinum as a novel wound healing system and as a scaffold for tissue regeneration.

  4. Preparation of Oriented Bundle-like Bacterial Cellulose by Capillary Templated%以毛细管为模板定向生长束状细菌纤维素

    Institute of Scientific and Technical Information of China (English)

    杨发禄; 罗庆平; 马拥军; 段晓惠; 裴重华

    2009-01-01

    以木醋杆菌(Acetobacter xylinum)为菌种,蛋白胨、酵母膏为培养基,毛细管为模板获得了定向生长的束状细菌纤维素,并研究了培养时间对束状细菌纤维素生长的影响,发现培养10d为最佳.用扫描电子显微镜(SEM)和傅里叶变换红外光谱仪(FT-IR)分析了束状细菌纤维素的结构.

  5. Mutation and selection of low temperature-resistant bacteria for cellulose production%细菌纤维素耐低温生产菌株的诱变选育

    Institute of Scientific and Technical Information of China (English)

    王海波; 马霞; 王腾飞; 任尚美; 关凤梅

    2008-01-01

    以实验室保存的木醋杆菌(Acetobacter xylinum)为出发菌株,利用紫外诱变的方法,以获取在低温条件下能高产细菌纤维素的突变株.通过初筛和复筛以及连续传代实验,确定了1株突变性状能稳定遗传的突变株,产量可达8.6g/L(干重),比原出发菌株产量提高了20%.

  6. 细菌纤维素对木质文物修复的初步探索%Preliminary research on the usage of bacterial cellulose for the repair of wooden artifacts

    Institute of Scientific and Technical Information of China (English)

    周松峦; 卫扬波; 李壶葳; 黄玉屏; 沈萍

    2008-01-01

    为研究细菌纤维素对木质文物的修复效果,首先检测了产纤维素的醋杆菌Acetobacter sp.PDA静置培养时的生长,然后将其与小块的饱水木材一起静置培养,通过测定木块处理前后的湿重及扫描电镜观察,结果显示细菌纤维素对木质文物有一定的修复作用.

  7. Preliminary Research on Structure and Properties of Nano-cellulose

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The structure of bacterial cellulose (BC) produced by Acetobacter xylinum NUST4 (A.xylinum NUST4) under static (SBC) and shake culture condition (ABC) was studied by means of transmission electron microscopic (TEM), X-ray diffraction (XRD) and Fourier transform-infrared spectrum (FT-IR). It was revealed that BC is Ⅰ crystal cellulose and the proportion of cellulose Ⅰα exceeds 80% and BC diameter is 10-80 nm.Mechanical properties and water absorption capacity were also determined. These properties could result from crystalline and nanometer structure of BC.

  8. Biological degradation of heavy mineral soaps

    Energy Technology Data Exchange (ETDEWEB)

    Glombitza, F.; Iske, U.; Bullmann, M.

    1988-11-01

    The possibility of biological degradation is exemplified by a chemically highly resistant Zircon mineral of the heavy mineral soaps of the Baltic Sea, with the aid of Thiobacillus ferrooxidans and Acetobacter spec. strains. The total matrix of the mineral is dissolved and all trace elements contained are solubilized. The different mechanisms of the leaching reaction give different distributions of the dissolved compounds in the phases of the leaching system. Concerning the REE a selectivity based on their physical characteristics is observed. There is a preferential solution of the light REE as compared to the heavy REE. The conditions of use are discussed.

  9. Lactobionic and cellobionic acid production profiles of the resting cells of acetic acid bacteria.

    Science.gov (United States)

    Kiryu, Takaaki; Kiso, Taro; Nakano, Hirofumi; Murakami, Hiromi

    2015-01-01

    Lactobionic acid was produced by acetic acid bacteria to oxidize lactose. Gluconobacter spp. and Gluconacetobacter spp. showed higher lactose-oxidizing activities than Acetobacter spp. Gluconobacter frateurii NBRC3285 produced the highest amount of lactobionic acid per cell, among the strains tested. This bacterium assimilated neither lactose nor lactobionic acid. At high lactose concentration (30%), resting cells of the bacterium showed sufficient oxidizing activity for efficient production of lactobionic acid. These properties may contribute to industrial production of lactobionic acid by the bacterium. The bacterium showed higher oxidizing activity on cellobiose than that on lactose and produced cellobionic acid. PMID:25965080

  10. Badania nad zastosowaniem celulozy bakteryjnej w konserwacji i restauracji dzieł sztuki

    OpenAIRE

    Rosa, Halina; Strzelczyk, Alicja Barbara; Jabłońska, Elżbieta; Kozielec, Tomasz; Karbowska-Berent, Joanna

    2012-01-01

    Bacterial cellulose (BC) obtained in the bacterial biosynthesis by Acetobacter xylinum is considered one of the most interesting materials tested and used in different areas of the human activity. Successful its applications in medicine and food industry launched a study of this material on a large scale. Many characteristic and unique properties of bacterial cellulose are used already in the paper industry Research and application of bacterial cellulose nano fibers made up of cellulose, its ...

  11. Bacteria isolated from Korean black raspberry vinegar with low biogenic amine production in wine

    Directory of Open Access Journals (Sweden)

    Nho-Eul Song

    2016-06-01

    Full Text Available Abstract A high concentration of histamine, one of the biogenic amines (BAs usually found in fermented foods, can cause undesirable physiological side effects in sensitive humans. The objective of this study is to isolate indigenous Acetobacter strains from naturally fermented Bokbunja vinegar in Korea with reduced histamine production during starter fermentation. Further, we examined its physiological and biochemical properties, including BA synthesis. The obtained strain MBA-77, identified as Acetobacter aceti by 16S rDNA homology and biochemical analysis and named A. aceti MBA-77. A. aceti MBA-77 showed optimal acidity % production at pH 5; the optimal temperature was 25 °C. When we prepared and examined the BAs synthesis spectrum during the fermentation process, Bokbunja wine fermented with Saccharomyces cerevisiae showed that the histamine concentration increased from 2.72 of Bokbunja extract to 5.29 mg/L and cadaverine and dopamine was decreased to 2.6 and 10.12 mg/L, respectively. Bokbunja vinegar prepared by A. aceti MBA-77 as the starter, the histamine concentration of the vinegar preparation step was decreased up to 3.66 mg/L from 5.29 mg/L in the wine preparation step. To our knowledge, this is the first report to demonstrate acetic acid bacteria isolated from Bokbunja seed vinegar with low spectrum BA and would be useful for wellbeing vinegar preparation.

  12. Acetic acid bacteria: A group of bacteria with versatile biotechnological applications.

    Science.gov (United States)

    Saichana, Natsaran; Matsushita, Kazunobu; Adachi, Osao; Frébort, Ivo; Frebortova, Jitka

    2015-11-01

    Acetic acid bacteria are gram-negative obligate aerobic bacteria assigned to the family Acetobacteraceae of Alphaproteobacteria. They are members of the genera Acetobacter, Gluconobacter, Gluconacetobacter, Acidomonas, Asaia, Kozakia, Swaminathania, Saccharibacter, Neoasaia, Granulibacter, Tanticharoenia, Ameyamaea, Neokomagataea, and Komagataeibacter. Many strains of Acetobacter and Komagataeibacter have been known to possess high acetic acid fermentation ability as well as the acetic acid and ethanol resistance, which are considered to be useful features for industrial production of acetic acid and vinegar, the commercial product. On the other hand, Gluconobacter strains have the ability to perform oxidative fermentation of various sugars, sugar alcohols, and sugar acids leading to the formation of several valuable products. Thermotolerant strains of acetic acid bacteria were isolated in order to serve as the new strains of choice for industrial fermentations, in which the cooling costs for maintaining optimum growth and production temperature in the fermentation vessels could be significantly reduced. Genetic modifications by adaptation and genetic engineering were also applied to improve their properties, such as productivity and heat resistance.

  13. Exploring the Bacterial Microbiota of Colombian Fermented Maize Dough "Masa Agria" (Maiz Añejo).

    Science.gov (United States)

    Chaves-Lopez, Clemencia; Serio, Annalisa; Delgado-Ospina, Johannes; Rossi, Chiara; Grande-Tovar, Carlos D; Paparella, Antonello

    2016-01-01

    Masa Agria is a naturally fermented maize dough produced in Colombia, very common in the traditional gastronomy. In this study we used culture-dependent and RNA-based pyrosequencing to investigate the bacterial community structure of Masa Agria samples produced in the south west of Colombia. The mean value of cell density was 7.6 log CFU/g of presumptive lactic acid bacteria, 5.4 log cfu/g for presumptive acetic bacteria and 5.6 og CFU/g for yeasts. The abundance of these microorganisms is also responsible for the low pH (3.1-3.7) registered. Although the 16S rRNA pyrosequencing revealed that the analyzed samples were different in bacteria richness and diversity, the genera Lactobacillus, Weissella, and Acetobacter were predominant. In particular, the most common species were Lactobacillus plantarum and Acetobacter fabarum, followed by L. fermentum, L. vaccinostercus, and Pediococcus argentinicus. Several microorganisms of environmental origin, such as Dechloromonas and most of all Sphingobium spp., revealed in each sample, were detected, and also bacteria related to maize, such as Phytoplasma. In conclusion, our results elucidated for the first time the structures of the bacterial communities of Masa Agria samples obtained from different producers, identifying the specific dominant species and revealing a complete picture of the bacterial consortium in this specific niche. The selective pressure of tropical environments may favor microbial biodiversity characterized by a useful technological potential.

  14. Exploring flavour-producing core microbiota in multispecies solid-state fermentation of traditional Chinese vinegar.

    Science.gov (United States)

    Wang, Zong-Min; Lu, Zhen-Ming; Shi, Jin-Song; Xu, Zheng-Hong

    2016-01-01

    Multispecies solid-state fermentation (MSSF), a natural fermentation process driven by reproducible microbiota, is an important technique to produce traditional fermented foods. Flavours, skeleton of fermented foods, was mostly produced by microbiota in food ecosystem. However, the association between microbiota and flavours and flavour-producing core microbiota are still poorly understood. Here, acetic acid fermentation (AAF) of Zhenjiang aromatic vinegar was taken as a typical case of MSSF. The structural and functional dynamics of microbiota during AAF process was determined by metagenomics and favour analyses. The dominant bacteria and fungi were identified as Acetobacter, Lactobacillus, Aspergillus, and Alternaria, respectively. Total 88 flavours including 2 sugars, 9 organic acids, 18 amino acids, and 59 volatile flavours were detected during AAF process. O2PLS-based correlation analysis between microbiota succession and flavours dynamics showed bacteria made more contribution to flavour formation than fungi. Seven genera including Acetobacter, Lactobacillus, Enhydrobacter, Lactococcus, Gluconacetobacer, Bacillus and Staphylococcus were determined as functional core microbiota for production of flavours in Zhenjiang aromatic vinegar, based on their dominance and functionality in microbial community. This study provides a perspective for bridging the gap between the phenotype and genotype of ecological system, and advances our understanding of MSSF mechanisms in Zhenjiang aromatic vinegar. PMID:27241188

  15. Cellulose synthesizing Complexes in Vascular Plants andProcaryotes

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Richard M, Jr; Saxena, Inder Mohan

    2009-07-07

    Continuing the work initiated under DE-FG03-94ER20145, the following major accomplishments were achieved under DE-FG02-03ER15396 from 2003-2007: (a) we purified the acsD gene product of the Acetobacter cellulose synthase operon as well as transferred the CesA cellulose gene from Gossypium into E. coli in an attempt to crystallize this protein for x-ray diffraction structural analysis; however, crystallization attempts proved unsuccessful; (b) the Acetobacter cellulose synthase operon was successfully incorporated into Synechococcus, a cyanobacterium2; (c) this operon in Synechococcus was functionally expressed; (d) we successfully immunolabeled Vigna cellulose and callose synthase components and mapped their distribution before and after wounding; (e) we developed a novel method to produce replicas of cellulose synthases in tobacco BY-2 cells, and we demonstrated the cytoplasmic domain of the rosette TC; (f) from the moss Physcomitrella, we isolated two full-length cDNA sequences of cellulose synthase (PpCesA1 and PpCesA2) and attempted to obtain full genomic DNA sequences; (g) we examined the detailed molecular structure of a new form of non-crystalline cellulose known as nematic ordered cellulose (=NOC)3.

  16. Exploring flavour-producing core microbiota in multispecies solid-state fermentation of traditional Chinese vinegar.

    Science.gov (United States)

    Wang, Zong-Min; Lu, Zhen-Ming; Shi, Jin-Song; Xu, Zheng-Hong

    2016-01-01

    Multispecies solid-state fermentation (MSSF), a natural fermentation process driven by reproducible microbiota, is an important technique to produce traditional fermented foods. Flavours, skeleton of fermented foods, was mostly produced by microbiota in food ecosystem. However, the association between microbiota and flavours and flavour-producing core microbiota are still poorly understood. Here, acetic acid fermentation (AAF) of Zhenjiang aromatic vinegar was taken as a typical case of MSSF. The structural and functional dynamics of microbiota during AAF process was determined by metagenomics and favour analyses. The dominant bacteria and fungi were identified as Acetobacter, Lactobacillus, Aspergillus, and Alternaria, respectively. Total 88 flavours including 2 sugars, 9 organic acids, 18 amino acids, and 59 volatile flavours were detected during AAF process. O2PLS-based correlation analysis between microbiota succession and flavours dynamics showed bacteria made more contribution to flavour formation than fungi. Seven genera including Acetobacter, Lactobacillus, Enhydrobacter, Lactococcus, Gluconacetobacer, Bacillus and Staphylococcus were determined as functional core microbiota for production of flavours in Zhenjiang aromatic vinegar, based on their dominance and functionality in microbial community. This study provides a perspective for bridging the gap between the phenotype and genotype of ecological system, and advances our understanding of MSSF mechanisms in Zhenjiang aromatic vinegar.

  17. Bacteria isolated from Korean black raspberry vinegar with low biogenic amine production in wine.

    Science.gov (United States)

    Song, Nho-Eul; Cho, Hyoun-Suk; Baik, Sang-Ho

    2016-01-01

    A high concentration of histamine, one of the biogenic amines (BAs) usually found in fermented foods, can cause undesirable physiological side effects in sensitive humans. The objective of this study is to isolate indigenous Acetobacter strains from naturally fermented Bokbunja vinegar in Korea with reduced histamine production during starter fermentation. Further, we examined its physiological and biochemical properties, including BA synthesis. The obtained strain MBA-77, identified as Acetobacter aceti by 16S rDNA homology and biochemical analysis and named A. aceti MBA-77. A. aceti MBA-77 showed optimal acidity % production at pH 5; the optimal temperature was 25°C. When we prepared and examined the BAs synthesis spectrum during the fermentation process, Bokbunja wine fermented with Saccharomyces cerevisiae showed that the histamine concentration increased from 2.72 of Bokbunja extract to 5.29mg/L and cadaverine and dopamine was decreased to 2.6 and 10.12mg/L, respectively. Bokbunja vinegar prepared by A. aceti MBA-77 as the starter, the histamine concentration of the vinegar preparation step was decreased up to 3.66mg/L from 5.29mg/L in the wine preparation step. To our knowledge, this is the first report to demonstrate acetic acid bacteria isolated from Bokbunja seed vinegar with low spectrum BA and would be useful for wellbeing vinegar preparation. PMID:26991285

  18. Exploring the Bacterial Microbiota of Colombian Fermented Maize Dough “Masa Agria” (Maiz Añejo)

    Science.gov (United States)

    Chaves-Lopez, Clemencia; Serio, Annalisa; Delgado-Ospina, Johannes; Rossi, Chiara; Grande-Tovar, Carlos D.; Paparella, Antonello

    2016-01-01

    Masa Agria is a naturally fermented maize dough produced in Colombia, very common in the traditional gastronomy. In this study we used culture-dependent and RNA-based pyrosequencing to investigate the bacterial community structure of Masa Agria samples produced in the south west of Colombia. The mean value of cell density was 7.6 log CFU/g of presumptive lactic acid bacteria, 5.4 log cfu/g for presumptive acetic bacteria and 5.6 og CFU/g for yeasts. The abundance of these microorganisms is also responsible for the low pH (3.1–3.7) registered. Although the 16S rRNA pyrosequencing revealed that the analyzed samples were different in bacteria richness and diversity, the genera Lactobacillus, Weissella, and Acetobacter were predominant. In particular, the most common species were Lactobacillus plantarum and Acetobacter fabarum, followed by L. fermentum, L. vaccinostercus, and Pediococcus argentinicus. Several microorganisms of environmental origin, such as Dechloromonas and most of all Sphingobium spp., revealed in each sample, were detected, and also bacteria related to maize, such as Phytoplasma. In conclusion, our results elucidated for the first time the structures of the bacterial communities of Masa Agria samples obtained from different producers, identifying the specific dominant species and revealing a complete picture of the bacterial consortium in this specific niche. The selective pressure of tropical environments may favor microbial biodiversity characterized by a useful technological potential. PMID:27524979

  19. Exploring the bacterial microbiota of Colombian fermented maize dough “Masa Agria” (Maiz Añejo

    Directory of Open Access Journals (Sweden)

    Clemencia Chaves

    2016-07-01

    Full Text Available Masa Agria is a naturally fermented maize dough produced in Colombia, very common in the traditional gastronomy. In this study we used culture-dependent and RNA-based pyrosequencing to investigate the bacterial community structure of Masa Agria samples produced in the south west of Colombia. The mean value of cell density was 7.6 Log CFU/g of presumptive lactic acid bacteria (LAB, 5.4 Log cfu/g for presumptive acetic bacteria and 5.6 Log CFU/g for yeasts. The abundance of these microorganisms is also responsible for the low pH (3.1-3.7 registered. Although the 16S rRNA pyrosequencing revealed that the analyzed samples were different in bacteria richness and diversity, the genera Lactobacillus, Weissella and Acetobacter were predominant. In particular, the most common species were Lactobacillus plantarum and Acetobacter fabarum, followed by Lb. fermentum, Lb. vaccinostercus and Pediococcus argentinicus. Several microorganisms of environmental origin, such as Dechloromonas and most of all Sphingobium spp., revealed in each sample, were detected, and also bacteria related to maize, such as Phytoplasma. In conclusion, our results elucidated for the first time the structures of the bacterial communities of Masa Agria samples obtained from different producers, identifying the specific dominant species and revealing a complete picture of the bacterial consortium in this specific niche. The selective pressure of tropical environments may favour microbial biodiversity characterized by a useful technological potential.

  20. Screening of main microorganism from Kefir Grain and analysis of femented milk using mixed microsapsule pure cultures%开菲尔粒中主要组成菌的分离鉴定及微囊化纯培养混合发酵指标分析

    Institute of Scientific and Technical Information of China (English)

    钟浩; 王亮; 刘克营; 郭爱珍; 胡曼; 刘朋龙; 齐向辉; 蔡梅红

    2016-01-01

    开菲尔粒是一个复杂的微生物共生体系,包含很多有益生作用的微生物.本文研究了一种开菲尔粒的主要组成菌并制成发酵剂.通过形态学特征初步分离纯化得出:该开菲尔粒样品主要由两株酵母菌、三株乳酸菌以及两株醋酸菌构成.经16S rDNA序列分析进一步确定其种属,得出其分别为Kluyveromyces marxianus和Pichia kudriavzevii、Lactobacillus pontis和Lactobacillus kefiri、Acetobacter lovaniensis和Acetobacter cibinongensis.采用分离出的菌株纯培养微囊化之后进行混合发酵,得到具有优良稳定发酵性能的混合发酵剂,测定结果显示发酵乳的营养成分、挥发性成分和抑菌性与原粒对比十分接近.

  1. Delayed development induced by toxicity to the host can be inherited by a bacterial-dependent, transgenerational effect

    Directory of Open Access Journals (Sweden)

    Yael eFridmann-Sirkis

    2014-02-01

    Full Text Available Commensal gut bacteria in many species including flies are integral part of their host, and are known to influence its development and homeostasis within generation. Here we report an unexpected impact of host-microbe interactions, which mediates multi-generational, non-Mendelian inheritance of a stress-induced phenotype. We have previously shown that exposure of fly larvae to G418 antibiotic induces transgenerationally heritable phenotypes, including a delay in larval development, gene induction in the gut and morphological changes. We now show that G418 selectively depletes commensal Acetobacter species and that this depletion explains the heritable delay, but not the inheritance of the other phenotypes. Notably, the inheritance of the delay was mediated by a surprising trans-generational effect. Specifically, bacterial removal from F1 embryos did not induce significant delay in F1 larvae, but nonetheless led to a considerable delay in F2. This effect maintains a delay induced by bacterial-independent G418 toxicity to the host. In line with these findings, reintroduction of isolated Acetobacter species prevented the inheritance of the delay. We further show that this prevention is partly mediated by vitamin B2 (Riboflavin produced by these bacteria; exogenous Riboflavin led to partial prevention and inhibition of Riboflavin synthesis compromised the ability of the bacteria to prevent the inheritance.These results identify host-microbe interactions as a hitherto unrecognized factor capable of mediating non-Mendelian inheritance of a stress-induced phenotype.

  2. Pembuatan Film Selulosa dari Nata de Pina

    Directory of Open Access Journals (Sweden)

    Iskandar Iskandar

    2010-06-01

    Full Text Available Preparation of cellulose film from nata de pina, a product of pinapple fermentation, using acetobacter xylinum was done at room temperature for 15 days. The aim of the research is to investigate the effect of sugar concentration and pH on film quality. The fermentation run at sugar concentration of 0, 5, 7.5, 10 and 12.5% and at pH of 3, 5 and 7. Results show that the best nata de pina was obtained at sugar concentration of 10% and pH 5. At these conditions, maximum nata precipitates rendemen was 26,80%, with a moisture content of 80,55%, and the thickness of 3,30 cm. The product nata then can be used to produce cellulose film. The characteristic of the produced film were 8,20 Kgf/mm2 and 11,71% for maximum tensile strength and elongation, respectively. Keywords: acetobacter xylinum, film, nata de pina, selulosa

  3. 柑桔果醋酿造用菌种分离及其生产性能测定%Isolation and characteristics of high-yield bacterial strains in citrus vinegar fermentation

    Institute of Scientific and Technical Information of China (English)

    刘青娥; 钟仙龙

    2015-01-01

    为筛选出适于柑桔果醋酿造的专用菌种,提高果醋品质,以自然酸发酵的柑桔醋液为菌源,利用钙平板筛选性能优异的醋酸菌,并对其进行鉴定及产酸量、产酯量、耐酒精度、耐温性能和稳定性等性能指标检测.结果共筛选出41株醋酸菌,其中ZY.C4和ZY.A5菌株产酸量较高,经鉴定分别为苹果醋杆菌(Acetobacter malorum)和恶臭醋杆菌(Acetobacter rancens),均不产生肠毒素.ZY.C4菌株的产酸产酯能力、耐温性能和耐酒精能力均优于ZY.A5菌株和对照菌株沪酿1.01,其最适发酵时间为5d,最佳发酵温度为31℃,最适初始酒度为7%;传代5次性能稳定,适合于柑桔果醋酿制.

  4. NATURAL MICROFLORA OF WINE GRAPE BERRIES

    Directory of Open Access Journals (Sweden)

    Attila Kántor

    2015-02-01

    Full Text Available The diversity of yeasts and bacterial species on grapes has been investigated in vineyards worldwide. For winemaking are very important three groups of microorganisms. First two includes acetic acid and lactic acid bacteria; they live and grow normally on grape surface. The third group includes more than 20 detectable genera of yeasts. There are three principal genera found on grapes Hanseniaspora uvarum (Kloeckera apiculata, Metschnikowia pulcherrima (Candida pulcherrima, and Candida stellata or new descripted Candida zemplinina. Aim of this study was investigate of number of three major groups of microorganisms which are important for grapes and winemaking. The number of bacteria on Acetobacter agar (AA ranged from 1.76 log CFU/mL to 2.80 log CFU/mL. Lactic acid bacteria were counted on MRS agar and the number of detectable colonies ranged from 0.48 log CFU/mL to 2.06 log CFU/mL. Sabouraud dextrose agar (SDA was used for cultivation of yeast and the number of yeasts ranged from 2.47 log CFU/mL to 2.76 log CFU/mL. For identification of yeast species were used different types of agar media with acid base indicator bromocresol green. Identified 10 yeasts species includes to genus: Candida, Metschnikowia, Pichia, Kluyveromyces, Hanseniaspora, Hansenula, Candida, Debaromyces, Rhodotorula and Saccharomyces. We identified only few bacterial species includes to genus Lactobacillus, Pediococcus, Gluconobacter and Acetobacter.

  5. The utilization of sugar cane molasses with/without the presence of lignosulfonate for the production of bacterial cellulose.

    Science.gov (United States)

    Keshk, Sherif; Sameshima, Kazuhiko

    2006-09-01

    Production of bacterial cellulose (BC) using sugar cane molasses (MO) with/without the presence of lignosulfonate (MOL) as a sole carbon source in a Hestrin-Schramm medium (HS) was investigated. Six strains of Acetobacter xylinum [American Type Culture Collection 10245 and Institute of Fermentation in Osaka (IFO) 13693, 13772, 13773, 14815, and 15237] were screened for their BC production. The yield of the BC among all the strains from both the MO and MOL media was much higher than that from the HS medium. Acetobacter xylinum IFO 13772 was the best BC producer for all media. Furthermore, physical properties of these BC from the HS, MO, and MOL media were studied using Fourier-transform infrared spectroscopy, X-ray diffractometer, and cross polarization/magic angle spinning 13C nuclear magnetic resonance. There are no significant differences in the crystallinity and the recorded Ialpha fraction among the BC produced from the different media. A remarkable difference was only recorded in terms of viscosity. These results indicate that MO is a better carbon source than glucose for most of the strains investigated. PMID:16450110

  6. Diversity of the microbiota involved in wine and organic apple cider submerged vinegar production as revealed by DHPLC analysis and next-generation sequencing.

    Science.gov (United States)

    Trček, Janja; Mahnič, Aleksander; Rupnik, Maja

    2016-04-16

    Unfiltered vinegar samples collected from three oxidation cycles of the submerged industrial production of each, red wine and organic apple cider vinegars, were sampled in a Slovene vinegar producing company. The samples were systematically collected from the beginning to the end of an oxidation cycle and used for culture-independent microbial analyses carried out by denaturing high pressure liquid chromatography (DHPLC) and Illumina MiSeq sequencing of 16S rRNA gene variable regions. Both approaches showed a very homogeneous bacterial structure during wine vinegar production but more heterogeneous during organic apple cider vinegar production. In all wine vinegar samples Komagataeibacter oboediens (formerly Gluconacetobacter oboediens) was a predominating species. In apple cider vinegar the acetic acid and lactic acid bacteria were two major groups of bacteria. The acetic acid bacterial consortium was composed of Acetobacter and Komagataeibacter with the Komagataeibacter genus outcompeting the Acetobacter in all apple cider vinegar samples at the end of oxidation cycle. Among the lactic acid bacterial consortium two dominating genera were identified, Lactobacillus and Oenococcus, with Oenococcus prevailing with increasing concentration of acetic acid in vinegars. Unexpectedly, a minor genus of the acetic acid bacterial consortium in organic apple cider vinegar was Gluconobacter, suggesting a possible development of the Gluconobacter population with a tolerance against ethanol and acetic acid. Among the accompanying bacteria of the wine vinegar, the genus Rhodococcus was detected, but it decreased substantially by the end of oxidation cycles.

  7. Diversity of the microbiota involved in wine and organic apple cider submerged vinegar production as revealed by DHPLC analysis and next-generation sequencing.

    Science.gov (United States)

    Trček, Janja; Mahnič, Aleksander; Rupnik, Maja

    2016-04-16

    Unfiltered vinegar samples collected from three oxidation cycles of the submerged industrial production of each, red wine and organic apple cider vinegars, were sampled in a Slovene vinegar producing company. The samples were systematically collected from the beginning to the end of an oxidation cycle and used for culture-independent microbial analyses carried out by denaturing high pressure liquid chromatography (DHPLC) and Illumina MiSeq sequencing of 16S rRNA gene variable regions. Both approaches showed a very homogeneous bacterial structure during wine vinegar production but more heterogeneous during organic apple cider vinegar production. In all wine vinegar samples Komagataeibacter oboediens (formerly Gluconacetobacter oboediens) was a predominating species. In apple cider vinegar the acetic acid and lactic acid bacteria were two major groups of bacteria. The acetic acid bacterial consortium was composed of Acetobacter and Komagataeibacter with the Komagataeibacter genus outcompeting the Acetobacter in all apple cider vinegar samples at the end of oxidation cycle. Among the lactic acid bacterial consortium two dominating genera were identified, Lactobacillus and Oenococcus, with Oenococcus prevailing with increasing concentration of acetic acid in vinegars. Unexpectedly, a minor genus of the acetic acid bacterial consortium in organic apple cider vinegar was Gluconobacter, suggesting a possible development of the Gluconobacter population with a tolerance against ethanol and acetic acid. Among the accompanying bacteria of the wine vinegar, the genus Rhodococcus was detected, but it decreased substantially by the end of oxidation cycles. PMID:26897250

  8. Acetic acid bacteria: A group of bacteria with versatile biotechnological applications.

    Science.gov (United States)

    Saichana, Natsaran; Matsushita, Kazunobu; Adachi, Osao; Frébort, Ivo; Frebortova, Jitka

    2015-11-01

    Acetic acid bacteria are gram-negative obligate aerobic bacteria assigned to the family Acetobacteraceae of Alphaproteobacteria. They are members of the genera Acetobacter, Gluconobacter, Gluconacetobacter, Acidomonas, Asaia, Kozakia, Swaminathania, Saccharibacter, Neoasaia, Granulibacter, Tanticharoenia, Ameyamaea, Neokomagataea, and Komagataeibacter. Many strains of Acetobacter and Komagataeibacter have been known to possess high acetic acid fermentation ability as well as the acetic acid and ethanol resistance, which are considered to be useful features for industrial production of acetic acid and vinegar, the commercial product. On the other hand, Gluconobacter strains have the ability to perform oxidative fermentation of various sugars, sugar alcohols, and sugar acids leading to the formation of several valuable products. Thermotolerant strains of acetic acid bacteria were isolated in order to serve as the new strains of choice for industrial fermentations, in which the cooling costs for maintaining optimum growth and production temperature in the fermentation vessels could be significantly reduced. Genetic modifications by adaptation and genetic engineering were also applied to improve their properties, such as productivity and heat resistance. PMID:25485864

  9. Exploring flavour-producing core microbiota in multispecies solid-state fermentation of traditional Chinese vinegar

    Science.gov (United States)

    Wang, Zong-Min; Lu, Zhen-Ming; Shi, Jin-Song; Xu, Zheng-Hong

    2016-01-01

    Multispecies solid-state fermentation (MSSF), a natural fermentation process driven by reproducible microbiota, is an important technique to produce traditional fermented foods. Flavours, skeleton of fermented foods, was mostly produced by microbiota in food ecosystem. However, the association between microbiota and flavours and flavour-producing core microbiota are still poorly understood. Here, acetic acid fermentation (AAF) of Zhenjiang aromatic vinegar was taken as a typical case of MSSF. The structural and functional dynamics of microbiota during AAF process was determined by metagenomics and favour analyses. The dominant bacteria and fungi were identified as Acetobacter, Lactobacillus, Aspergillus, and Alternaria, respectively. Total 88 flavours including 2 sugars, 9 organic acids, 18 amino acids, and 59 volatile flavours were detected during AAF process. O2PLS-based correlation analysis between microbiota succession and flavours dynamics showed bacteria made more contribution to flavour formation than fungi. Seven genera including Acetobacter, Lactobacillus, Enhydrobacter, Lactococcus, Gluconacetobacer, Bacillus and Staphylococcus were determined as functional core microbiota for production of flavours in Zhenjiang aromatic vinegar, based on their dominance and functionality in microbial community. This study provides a perspective for bridging the gap between the phenotype and genotype of ecological system, and advances our understanding of MSSF mechanisms in Zhenjiang aromatic vinegar. PMID:27241188

  10. Exploring the Bacterial Microbiota of Colombian Fermented Maize Dough "Masa Agria" (Maiz Añejo).

    Science.gov (United States)

    Chaves-Lopez, Clemencia; Serio, Annalisa; Delgado-Ospina, Johannes; Rossi, Chiara; Grande-Tovar, Carlos D; Paparella, Antonello

    2016-01-01

    Masa Agria is a naturally fermented maize dough produced in Colombia, very common in the traditional gastronomy. In this study we used culture-dependent and RNA-based pyrosequencing to investigate the bacterial community structure of Masa Agria samples produced in the south west of Colombia. The mean value of cell density was 7.6 log CFU/g of presumptive lactic acid bacteria, 5.4 log cfu/g for presumptive acetic bacteria and 5.6 og CFU/g for yeasts. The abundance of these microorganisms is also responsible for the low pH (3.1-3.7) registered. Although the 16S rRNA pyrosequencing revealed that the analyzed samples were different in bacteria richness and diversity, the genera Lactobacillus, Weissella, and Acetobacter were predominant. In particular, the most common species were Lactobacillus plantarum and Acetobacter fabarum, followed by L. fermentum, L. vaccinostercus, and Pediococcus argentinicus. Several microorganisms of environmental origin, such as Dechloromonas and most of all Sphingobium spp., revealed in each sample, were detected, and also bacteria related to maize, such as Phytoplasma. In conclusion, our results elucidated for the first time the structures of the bacterial communities of Masa Agria samples obtained from different producers, identifying the specific dominant species and revealing a complete picture of the bacterial consortium in this specific niche. The selective pressure of tropical environments may favor microbial biodiversity characterized by a useful technological potential. PMID:27524979

  11. Selection of protectants for freezing and freeze-drying of acetic acid bacteria%醋酸菌冷冻、冷干保护剂的选择

    Institute of Scientific and Technical Information of China (English)

    王娜; 国石磊; 张永祥; 彭利沙; 李军

    2015-01-01

    In order to increase their freezing survival rate and freeze-drying survival rate,the effect of different protectants on the survival of Acetobacter aceti and Acetobacter pasteurianus ssp.pasteurianus during different processes including freezing and freeze-drying were studied herein.The protection effects of the different protectants on freezing and freeze-drying were also estimated.The results showed that the freezing survival rate of Acetobacter aceti was as follows:trehalose(73.58%) > corn dextrin(62.26%) > skim milk powder(60.38%),which were significantly higher than that of the control group (24.53%).The freezing survival rate of Acetobacter pasteurianus ssp.pasteurianus was as follows:dextran (95.35%) > skim milk powder (89.53%) > corn dextrin (88.37%) > trehalose (52.32%),which were significantly higher than that of the control group (2.23%).The freeze-drying survival rate of Acetobacter aceti was as follows:skim milk powder(92.86%) > lactose(81.25%) > glucose(46.88%),which were significantly higher than that of the control group (22.25%).The freeze-drying survival rate of Acetobacter pasteurianus ssp.pasteurianus was as follows:skim milk powde(72.92%) > trehalose(31.25%),which were significantly higher than that of the control group (12.08%).The other protectants showed varying degrees of protection effect on the strains.Trehalose and skim milk powder were prior selection for the protections of Acetobacter.%为提高醋酸菌在冷冻及冷干过程中的存活率,考察了10种不同保护剂分别对醋化醋杆菌和巴氏醋杆菌巴士亚种存活率的影响,评价了10种不同保护剂对醋酸菌的冷冻及冷干保护作用.结果发现,醋化醋杆菌的冷冻存活率:海藻糖(73.58%)>玉米糊精(62.26%)>脱脂乳粉(60.38%),明显高于对照的24.53% (P<0.05);巴氏醋杆菌巴士亚种的冷冻存活率:葡聚糖(95.35%)>脱脂乳粉(89.53%)>玉米糊精(88.37

  12. 多菌株共生发酵蜂蜜醋饮料的工艺研究

    Institute of Scientific and Technical Information of China (English)

    徐伟; 杜鹃

    2014-01-01

    Taking linden tree honey as raw materials, Saccharomycodes ludwigii , Acetobacter aceti and Lactobacillus acidophilus are used to carry on symbiotic fermentation of mixed multiple strains, then take the four factors: symbiotic fermentation inoculation methods, fermentation temperature, inoculation and inoculation proportion to study on the effects on honey vinegar drink, by using L9(34) orthogonal test, symbiotic fermentation for 7 days. The results show that the optimum conditions are as follows: the symbiotic fermentation temperature is 32℃, inoculation is 4%, inoculation proportion is 1∶3∶1 (Saccharomycodes ludwigii∶Acetobacter acet∶Lactobacillus acidophilus) . In this fermented condition, the sugar concentration of honey vinegar drink is 6.5 g/dL, the total acid content (as acetic acid) is 5.1 g/dL.%以椴树蜜为原料,采用酿酒酵母(Saccharomycodes ludwigii)、醋化醋杆菌(Acetobacter aceti)与嗜酸乳杆菌(Lactobacillus acidophilus)混合多菌株共生发酵,研究共生发酵接种方式、发酵温度、接种量和接种比例4个因素对蜂蜜醋饮料的影响,采用L9(34)正交试验设计,共生发酵7 d。结果显示,优化条件为共生发酵温度32℃,混合接种量4%,接种比例1∶3∶1(酵母菌∶醋化醋杆菌∶嗜酸乳杆菌)。在此发酵条件下,蜂蜜醋饮料中总糖含量为6.5 g/dL,总酸含量(以醋酸计)为5.1 g/dL。

  13. 蜂蜜醋发酵及其智舌辨识的研究%Research on the Fermentation of Honey Vinegar and Its Detection with EIectronic Tongue

    Institute of Scientific and Technical Information of China (English)

    袁鹰; 常雅宁; 丁庆豹; 聂嘉睿

    2015-01-01

    Honey vinegar is produced through a two-step fermentation process,alcohol fermentation with immobilized yeast and acetic acid fermentation with acetobacter.The immobilized yeast is very stable and could be used for 15 times.After 72 hours'fermentation,the yield of acetic acid reaches 1 .9 g/dL when the original alcohol concentration is 4%and 2%inoculation amount of acetobacter and 0.25% yeast extract are added.The yield of acetic acid increases to 2.2 g/dL when 40% inoculation amount of acetobacter but no yeast extract are added.Due to many similarities,honey vinegar fermented above is distinguished and identified with electronic tongue to the class of fruit vinegar.%以蜂蜜为原料,经过固定化酵母和醋酸杆菌两步发酵得到蜂蜜醋。固定化酵母发酵生产酒精时,发酵批次最多可达15次。调整酒精度为4.0%时,向原料中添加0.25%酵母膏(YE+),接种量为2%时,经醋酸杆菌发酵72 h 乙酸量可达1.9 g/dL,相同条件下酵母膏未添加组(YE-)增加接种量至40%时,乙酸量增加至2.2 g/dL。利用智舌对发酵的蜂蜜醋进行辨识,发现蜂蜜醋与进口果醋在滋味等多个方面具有很高的相似性,因此本实验发酵所得蜂蜜醋总体口味可归于进口果醋一类。

  14. Synthesis of Hydrogel Based on Nata De Coco and Acrylic Acid as Co-Monomer Using Free Radical Polymerization Method

    International Nuclear Information System (INIS)

    Nata de Coco or known as bacterial cellulose is produced by Acetobacter xylinum where it is more stable than plant cellulose. Moreover, it also provides outstanding advantages to be developed as an environmental responsive hydrogels. In this study the bacterial cellulose-g-acrylic acid hydrogel was synthesized by using a free radical polymerization method. Ammonium persulfate (APS) was used to initiate the reaction, while N,N'-methylene bis acrylamide has been used as the crosslinking agent. In order to test the hydrogel respond, swelling tests were made at different pH. Furthermore, ATR-FTIR analysis was used to determine the interactions between bacterial cellulose and acrylic acid. Finally, the determination of glass transition (Tg) was made by using DSC. (author)

  15. Impact of gluconic fermentation of strawberry using acetic acid bacteria on amino acids and biogenic amines profile.

    Science.gov (United States)

    Ordóñez, J L; Sainz, F; Callejón, R M; Troncoso, A M; Torija, M J; García-Parrilla, M C

    2015-07-01

    This paper studies the amino acid profile of beverages obtained through the fermentation of strawberry purée by a surface culture using three strains belonging to different acetic acid bacteria species (one of Gluconobacter japonicus, one of Gluconobacter oxydans and one of Acetobacter malorum). An HPLC-UV method involving diethyl ethoxymethylenemalonate (DEEMM) was adapted and validated. From the entire set of 21 amino acids, multiple linear regressions showed that glutamine, alanine, arginine, tryptophan, GABA and proline were significantly related to the fermentation process. Furthermore, linear discriminant analysis classified 100% of the samples correctly in accordance with the microorganism involved. G. japonicus consumed glucose most quickly and achieved the greatest decrease in amino acid concentration. None of the 8 biogenic amines were detected in the final products, which could serve as a safety guarantee for these strawberry gluconic fermentation beverages, in this regard.

  16. Inoculant production in developing countries - Problems, potentials and success

    International Nuclear Information System (INIS)

    Sustainable agriculture is a long-term goal that seeks to overcome some of problems and constraints that confront the economic viability, environmental soundness and social acceptance of agricultural production systems. In this context, bio-fertilizers assume special significance particularly because they are 'eco-friendly', but also since their alternative, chemical fertilizers are expensive. Undoubtedly, the most commonly used bio-fertilizers are soil bacteria of the genus Rhizobium, but others like Azolla, Azospirillum, various cyanobacteria also contribute significant amounts of N to e.g. rice. Other bacteria like Frankia and Acetobacter contribute N to trees of the genus Casuarina and sugarcane, respectively. Furthermore, although they are rarely used as inoculants, vesicular arbuscular mycorrhizae (VAM) and phosphobacteria help countless plants solubilise and assimilate soil phosphorus. Despite these advantages, bio-fertilizers could be more widely used in developing countries. Contingent upon greater use is improved quality of the inoculants, and all aspects of their production are discussed here. (author)

  17. Genome sequence of Frateuria aurantia type strain (Kondo 67(T)), a xanthomonade isolated from Lilium auratium Lindl.

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Iain [U.S. Department of Energy, Joint Genome Institute; Teshima, Hazuki [Los Alamos National Laboratory (LANL); Nolan, Matt [U.S. Department of Energy, Joint Genome Institute; Lapidus, Alla L. [U.S. Department of Energy, Joint Genome Institute; Tice, Hope [U.S. Department of Energy, Joint Genome Institute; Glavina Del Rio, Tijana [U.S. Department of Energy, Joint Genome Institute; Cheng, Jan-Fang [U.S. Department of Energy, Joint Genome Institute; Han, Cliff [Los Alamos National Laboratory (LANL); Tapia, Roxanne [Los Alamos National Laboratory (LANL); Goodwin, Lynne A. [Los Alamos National Laboratory (LANL); Pitluck, Sam [U.S. Department of Energy, Joint Genome Institute; Liolios, Konstantinos [U.S. Department of Energy, Joint Genome Institute; Mavromatis, K [U.S. Department of Energy, Joint Genome Institute; Pagani, Ioanna [U.S. Department of Energy, Joint Genome Institute; Ivanova, N [U.S. Department of Energy, Joint Genome Institute; Mikhailova, Natalia [U.S. Department of Energy, Joint Genome Institute; Pati, Amrita [U.S. Department of Energy, Joint Genome Institute; Chen, Amy [U.S. Department of Energy, Joint Genome Institute; Palaniappan, Krishna [U.S. Department of Energy, Joint Genome Institute; Land, Miriam L [ORNL; Rohde, Manfred [HZI - Helmholtz Centre for Infection Research, Braunschweig, Germany; Lang, Elke [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Detter, J. Chris [U.S. Department of Energy, Joint Genome Institute; Goker, Markus [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Woyke, Tanja [U.S. Department of Energy, Joint Genome Institute; Bristow, James [U.S. Department of Energy, Joint Genome Institute; Eisen, Jonathan [U.S. Department of Energy, Joint Genome Institute; Markowitz, Victor [U.S. Department of Energy, Joint Genome Institute; Hugenholtz, Philip [U.S. Department of Energy, Joint Genome Institute; Kyrpides, Nikos C [U.S. Department of Energy, Joint Genome Institute; Klenk, Hans-Peter [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany

    2013-01-01

    rateuria aurantia (ex Kondo and Ameyama 1958) Swings et al. 1980 is a member of the bispecific genus Frateuria in the family Xanthomonadaceae, which is already heavily targeted for non-type strain genome sequencing. Strain Kondo 67(T) was initially (1958) identified as a member of 'Acetobacter aurantius', a name that was not considered for the approved list. Kondo 67(T) was therefore later designated as the type strain of the newly proposed acetogenic species Frateuria aurantia. The strain is of interest because of its triterpenoids (hopane family). F. aurantia Kondo 67(T) is the first member of the genus Frateura whose genome sequence has been deciphered, and here we describe the features of this organism, together with the complete genome sequence and annotation. The 3,603,458-bp long chromosome with its 3,200 protein-coding and 88 RNA genes is a part of the Genomic Encyclopedia of Bacteria and Archaea project.

  18. Impact of gluconic fermentation of strawberry using acetic acid bacteria on amino acids and biogenic amines profile.

    Science.gov (United States)

    Ordóñez, J L; Sainz, F; Callejón, R M; Troncoso, A M; Torija, M J; García-Parrilla, M C

    2015-07-01

    This paper studies the amino acid profile of beverages obtained through the fermentation of strawberry purée by a surface culture using three strains belonging to different acetic acid bacteria species (one of Gluconobacter japonicus, one of Gluconobacter oxydans and one of Acetobacter malorum). An HPLC-UV method involving diethyl ethoxymethylenemalonate (DEEMM) was adapted and validated. From the entire set of 21 amino acids, multiple linear regressions showed that glutamine, alanine, arginine, tryptophan, GABA and proline were significantly related to the fermentation process. Furthermore, linear discriminant analysis classified 100% of the samples correctly in accordance with the microorganism involved. G. japonicus consumed glucose most quickly and achieved the greatest decrease in amino acid concentration. None of the 8 biogenic amines were detected in the final products, which could serve as a safety guarantee for these strawberry gluconic fermentation beverages, in this regard. PMID:25704705

  19. Characterization of bacterial diversity in pulque, a traditional Mexican alcoholic fermented beverage, as determined by 16S rDNA analysis.

    Science.gov (United States)

    Escalante, Adelfo; Rodríguez, María Elena; Martínez, Alfredo; López-Munguía, Agustín; Bolívar, Francisco; Gosset, Guillermo

    2004-06-15

    The bacterial diversity in pulque, a traditional Mexican alcoholic fermented beverage, was studied in 16S rDNA clone libraries from three pulque samples. Sequenced clones identified as Lactobacillus acidophilus, Lactobacillus strain ASF360, L. kefir, L. acetotolerans, L. hilgardii, L. plantarum, Leuconostoc pseudomesenteroides, Microbacterium arborescens, Flavobacterium johnsoniae, Acetobacter pomorium, Gluconobacter oxydans, and Hafnia alvei, were detected for the first time in pulque. Identity of 16S rDNA sequenced clones showed that bacterial diversity present among pulque samples is dominated by Lactobacillus species (80.97%). Seventy-eight clones exhibited less than 95% of relatedness to NCBI database sequences, which may indicate the presence of new species in pulque samples.

  20. Effect of inoculation on strawberry fermentation and acetification processes using native strains of yeast and acetic acid bacteria.

    Science.gov (United States)

    Hidalgo, C; Torija, M J; Mas, A; Mateo, E

    2013-05-01

    The aim of this work was to analyze the microbiota involved in the traditional vinegar elaboration of strawberry fruit during a spontaneous and inoculated process. In the spontaneous processes, low biodiversity was detected in both alcoholic fermentation (AF) and acetification. Nevertheless, a strain of Saccharomyces cerevisiae and of Acetobacter malorum were selected and tested as starter cultures in the inoculation study. The inoculated processes with these strains were compared with another spontaneous process, yielding a significant reduction in time for AF with a total imposition of the S. cerevisiae strain. The resulting strawberry wine was acetified in different containers (glass and wood) yielding an initial imposition of the A. malorum inoculated strain, although displacement by Gluconacetobacter species was observed in the wood barrels. PMID:23498182

  1. Biosynthesis and Characterization of Nanocellulose-Gelatin Films

    Directory of Open Access Journals (Sweden)

    Muenduen Phisalaphong

    2013-02-01

    Full Text Available A nanocellulose-gelatin (bacterial cellulose gelatin (BCG film was developed by a supplement of gelatin, at a concentration of 1%–10% w/v, in a coconut-water medium under the static cultivation of Acetobacter xylinum. The two polymers exhibited a certain degree of miscibility. The BCG film displayed dense and uniform homogeneous structures. The Fourier transform infrared spectroscopy (FTIR results demonstrated interactions between the cellulose and gelatin. Incorporation of gelatin into a cellulose nanofiber network resulted in significantly improved optical transparency and water absorption capacity of the films. A significant drop in the mechanical strengths and a decrease in the porosity of the film were observed when the supplement of gelatin was more than 3% (w/v. The BCG films showed no cytotoxicity against Vero cells.

  2. Otimização da produção de nata (celulose bacteriana) por fermentação em superfície

    OpenAIRE

    DANESI Eliane Dalva Godoy; Wosiacki, Gilvan

    1998-01-01

    A nata de coco, alimento glicídico obtido por fermentação em superfície promovida por Acetobacter xylinum, é bastante difundida em alguns países asiáticos, principalmente nas Filipinas. Como meio de cultivo são utilizadas a água ou o leite de coco, produtos de baixo valor econômico e resíduos de processamento da fruta; há indicativos na literatura, entretanto, de que outros resíduos agro-industriais como soro de leite ou mesmo suco de frutas podem ser utilizados. A fim de avaliar a produção d...

  3. Bacterial cellulose membrane as separation medium

    Energy Technology Data Exchange (ETDEWEB)

    Shibazaki, Hideki; Kuga, Shigenori; Onabe, Fumihiko; Usuda, Makoto (Univ. of Toyko, (Japan). Faculty of Agriculture)

    1993-11-10

    A thin membrane of bacterial cellulose (BC) obtained from Acetobacter culture was tested for its performance as a dialysis membrane in aqueous systems. The BC membrane showed superior mechanical strength to that of a dialysis-grade regenerated cellulose membrane, allowing the use of a thinner membrane than the latter. As a result, the BC membrane gave higher permeation rates for poly(ethylene glycols) as probe solutes. The cutoff molecular weight of the original BC membrane, significantly greater than that of regenerated cellulose, could be modified by concentrated alkali treatments of the membrane. The nature of the change at the ultrastructural level caused by the alkali treatments was studied by X-ray diffraction and scanning electron microscopy.

  4. Determination of the size and phase composition of silver nanoparticles in a gel film of bacterial cellulose by small-angle X-ray scattering, electron diffraction, and electron microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Volkov, V. V.; Klechkovskaya, V. V., E-mail: klechvv@ns.crys.ras.ru; Shtykova, E. V.; Dembo, K. A.; Arkharova, N. A.; Ivakin, G. I. [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation); Smyslov, R. Yu. [Russian Academy of Sciences, Institute of Macromolecular Compounds (Russian Federation)

    2009-03-15

    The nanoscale structural features in a composite (gel film of Acetobacter Xylinum cellulose with adsorbed silver nanoparticles, stabilized by N-polyvinylpyrrolidone) have been investigated by small-angle X-ray scattering. The size distributions of inhomogeneities in the porous structure of the cellulose matrix and the size distributions of silver nanoparticles in the composite have been determined. It is shown that the sizes of synthesized nanoparticles correlate with the sizes of inhomogeneities in the gel film. Particles of larger size (with radii up to 100 nm) have also been found. Electron microscopy of thin cross sections of a dried composite layer showed that large particles are located on the cellulose layer surface. Electron diffraction revealed a crystal structure of silver nanoparticles in the composite.

  5. Taxonomy progress of acetic acid bacteria%醋酸菌的分类进展

    Institute of Scientific and Technical Information of China (English)

    王斌; 陈福生

    2014-01-01

    醋酸菌是好氧型革兰氏阴性菌,能以氧气为终端电子受体,氧化糖类、糖醇类和醇类生成相应的糖醇、酮和有机酸.从1898年Beijerinck定义第一个醋酸菌属-醋酸杆菌属(Acetobacter)以来,截止2014年初,已报道的醋酸菌共16个属,共84个种.该文总结了醋酸菌的分离、分类、鉴定与保藏方法,并对醋酸菌命名原则、种属名称演变以及醋酸菌的种属特征进行了归纳.

  6. 红茶菌中微生物的分离与初步鉴定%Isolation and Identification of Microorganisms from Kombucha Fungus Culture

    Institute of Scientific and Technical Information of China (English)

    张虎成; 张征田; 辛秀兰

    2011-01-01

    本实验对某红茶菌中的微生物菌种进行了分离,共得到70个菌株,其中酵母茵15株,醋酸茵30株,乳酸茵25株,经过初步鉴定得到6个茵种.分别为酿酒酵母Saccharomyces cerevisiae、粟酒裂殖酵母Schizosaccharomyces pombe、醋化醋杆菌木质亚种Acetobacter xylinum、液化醋杆茵A.liquefaciens、甲醇醋杆菌Acidomonas mnethanolica、乳杆菌Lactobacillus sp.

  7. Effect of polymer matrix on structure of Se particles formed in aqueous solutions during redox process

    Energy Technology Data Exchange (ETDEWEB)

    Suvorova, E. I., E-mail: suvorova@ns.crys.ras.ru; Klechkovskaya, V. V. [Shubnikov Institute of Crystallography of Russian Academy of Sciences (Russian Federation)

    2010-12-15

    Transmission electron microscopy and X-ray energy dispersive microanalysis study of the structure of particles formed during the reduction of Se(IV) to Se(0) in aqueous solutions in the presence of amphiphilic polymers showed the formation of Se/polymer composite particles. The content of carbon inside the particles can be as large as 80 at %. Polymers deeply influence the structure of particles. Depending on polymers, the composite particles may be unstable with time and they spontaneously evolve from Se/polymer composite particles to crystalline particles of monoclinic Se. For the stable ones, addition of bacterial cellulose Acetobacter xylinum gel-film can induce crystallization in the particles which expel the polymeric material. The Se/polymer composite particles and Se crystalline particles exhibit different sensitivity to electron irradiation and stiffness.

  8. 大豆乳清细菌纤维素在冰淇淋中的应用%Application of Cellulose from Bio-processed Soybean Whey in Ice Cream Formula

    Institute of Scientific and Technical Information of China (English)

    王璐; 杨谦; 李晓东

    2004-01-01

    研究使用Acetobacter xylinumC5菌种,利用大豆乳清发酵得到的细菌纤维素作为稳定剂,应用到冰淇淋的加工当中.试验证明,细菌纤维素可以替代黄原胶、卡拉胶等稳定剂添加到冰淇淋中,它能够改善口感,同时呈现爽口的香甜味.细菌纤维素冰淇淋的抗融性和融化特性都比较理想,融化率21.7%,膨胀率67%.同时产品具有一定的膳食保健功能.

  9. Ioslation and Identification of Nata-producing Strain and Studies on Fermentation Characteristics%纳塔产生菌的分离鉴定和发酵特性研究

    Institute of Scientific and Technical Information of China (English)

    刘四新; 李从发; 李枚秋; 方仲根; 康丽茹

    1999-01-01

    从变酸黄酒中分离到了一株纳塔(nata)产生菌W39,初步鉴定为醋酸杆菌属(Acetobacter).经显微镜、电镜观察及纤维素酶水解,知其所产纳塔主要成分为纤维素.研究了该菌在椰子水培养基上的发酵特性:经液态发酵产生不溶性的凝胶纤维素,且只在有氧生长时才合成纤维素;对无机盐和生长因子的要求复杂;用于纳塔生产时必须静置培养并保证液面与空气接触.

  10. ANOTHER NITROGEN-FIXING MICROORGANISM IN SUGARCANE STALKS: Bacillus brevis?

    Directory of Open Access Journals (Sweden)

    Lorelí de los A. Mirabal

    2000-01-01

    Full Text Available Con el objetivo de identificar un microorganismo formador de colonias blancas en medio de cultivo LGI, prove- niente de savia apoplástica del tallo de la caña de azúcar, se realizaron diferentes experimentos en los que se utilizó la variedad ML-318. De la misma se extrajo savia apoplástica, de la cual se aisló el microorganismo de interés, al que se le realizaron pruebas morfológicas, culturales y bioquímicas, las que revelaron un 65 % de probabilidad de que el microorganismo de interés se corresponde con Bacillus brevis. Se detectó actividad nitrogenasa por la reducción de acetileno a etileno. Además, los resultados indican interacción entre Acetobacter diazotrophicus y el microorganismo formador de colonias blancas identificado como Bacillus brevis.

  11. 细菌纤维素生物理化特性及其应用

    Institute of Scientific and Technical Information of China (English)

    范丽霞; 王锡彬; 杨先会

    2004-01-01

    细菌纤维素是由部分细菌产生的一类高分子化合物,最早由英国Brown在1886年发现,为了与植物来源的纤维素相区别,将其称之为“细菌纤维素”。某些细菌合成纤维的速度及产率要比植物高许多,木醋杆菌(Acetobacter xylinum,简称Ax)就是其中突出代表。Ax合成细菌纤维素在纯

  12. Study on biotransformation of old rice to bacterial cellulose%陈米生物转化为细菌纤维素的最优工艺研究

    Institute of Scientific and Technical Information of China (English)

    余冰; 李宗军

    2007-01-01

    以醋化醋杆菌(Acetobacter aceti)为出发菌株,细菌纤维素产量为指标,通过正交试验优化发酵培养基,其最优组成为:陈米糖化(米:水)(m:V=1:12)后的澄清液30%、蛋白胨0.5%,K2HPO4 0.1%,MgSO4 1.5%,乙醇1.5%.适宜的发酵方式为:接种培养36 h的种子液4%(V:V)在pH值5~6、30℃的条件下振荡发酵培养4 d.经验证试验,细菌纤维素产量可达7.34 g/L.

  13. 海带发酵液的制备及其对单胞藻生长的作用%Preparation of Laminaria japonica Fermentation Broth and Function on Unicellular Algae

    Institute of Scientific and Technical Information of China (English)

    殷丽莎; 韩晓弟

    2009-01-01

    用酿酒酵母(Saccbaromyces cerevisiae)和醋酸醋杆菌(Acetobacter aceti)发酵海带,将发酵液作为添加剂加入盐藻(Dunaliella salina)、新月菱形藻(Nitzsehia closteztuma)基本培养液(F/2培养液)中,定期计数以检测其生长状况.结果表明:海带发酵液对盐藻和新月菱形藻2种单胞藻生长具有促进作用.发酵液体积分数分别为2.5%和5%时,盐藻生长状况相似,而新月菱形藻则是在发酵液体积分数为2.5%时生长旺盛.

  14. Some Issues of Applying Bacterial Cellulose for the Preservation and Restoration of Wood Cultural Relics%细菌纤维素保护修复木质文物的若干问题

    Institute of Scientific and Technical Information of China (English)

    卫扬波

    2014-01-01

    通过研究产纤维素的醋杆菌Acetobacter sp.PDA菌静置培养时的生长,然后将其与小块的饱水木材一起静置培养,测定木块处理前后的湿重及扫描电镜观察的结果,肯定了细菌纤维素对木质文物有较好的修复效果.同时初步探讨了细菌纤维素修复木质文物现阶段存在的若干问题以及研究方向.

  15. Microbial Cellulose Assembly in Microgravity

    Science.gov (United States)

    Brown, R. Malcolm, Jr.

    1998-01-01

    Based on evidence indicating a possible correlation between hypo-gravity conditions and alteration of cellulose production by the gram negative bacterium, Acetobacter xylinum, a ground-based study for a possible long term Space Shuttle flight has been conducted. The proposed experiment for A. xylinum aboard the Shuttle is the BRIC (Biological Research in a Canister), a metal container containing spaces for nine Petri plates. Using a common experimental design, the cellulose production capability as well as the survivability of the A. xylinum strains NQ5 and AY201 have been described. It should now be possible to use the BRIC for the first long term microgravity experiments involving the biosynthesis of cellulose.

  16. High field nuclear magnetic resonance application to polysaccharide chemistry

    International Nuclear Information System (INIS)

    Nuclear magnetic resonance has been applied to polysaccharide chemistry using time averaging technique and high fields (100 and 250 MHz). The three methyl signals of methyl cellulose and cellulose triacetate are separated, and the C-6 substituent has been identified. Biosynthesis of bacterial cellulose has been performed using deuterium labelled D-glucose and Acetobacter xylinum. Per-acetylated derivative of bacterial cellulose has been studied by NMR; this study permitted us to determine the quantity of deuterium on each position of the anhydro-glucose unit in the polymer. NMR has also been used to see the anomeric end chain of cellulose and amylose derivatives and to show the fixation of bromine and t-butyl group on the free anomeric end chain of cellulose triacetate. (author)

  17. PENGARUH MEDIUM PERENDAM TERHADAP SIFAT MEKANIK, MORFOLOGI, DAN KINERJA MEMBRAN NATA DE COCO

    Directory of Open Access Journals (Sweden)

    Senny Widyaningsih

    2008-05-01

    Full Text Available Nata de coco is bacterial cellulose which is produced by Acetobacter xylinum in fermentation process of coconut water. Based on its properties, nata de coco can be used as a membrane. Soaking medium in purification of nata de coco gel can influence structure, morphology, and performance of nata de coco membrane. First medium was NaOCl 0.05% and NaOH 5%, Second medium was ultrasonic. Third medium was NaOH 1% and CH3COOH 1%. Mechanical property were analysized based on its tensile strength. Morphology of membrane was analysized using SEM. Performance of membrane was determined based on its permeability. The result showed that nata de coco membrane which had the best value on mechanical properties, morphology, and performance was membrane in third medium.

  18. Ocorrência de bactérias diazotróficas em diferentes genótipos de cana-de-açúcar Occurrence of diazotrophic bacteria in different sugar cane genotypes

    Directory of Open Access Journals (Sweden)

    FÁBIO BUENO DOS REIS JUNIOR

    2000-05-01

    Full Text Available O objetivo deste trabalho foi avaliar a localização e o número de bactérias endofíticas em quatro genótipos de cana-de-açúcar e investigar sobre a possível existência de correlação com os resultados apresentados em trabalhos de quantificação da fixação biológica de nitrogênio (FBN. Fez-se um levantamento das bactérias diazotróficas presentes, e quantificou-se a população de Herbaspirillum spp. e Acetobacter diazotrophicus, em genótipos de cana-de-açúcar contrastantes quanto à capacidade de obter N da FBN. De acordo com o levantamento realizado neste trabalho, as bactérias estudadas (Azospirillum lipoferum, A. brasilense, A. amazonense, Herbaspirillum spp. e Acetobacter diazotrophicus estavam presentes nos quatro genótipos avaliados e em todas as partes da planta, exceto A. amazonense, que não foi isolado de amostras de folhas. A quantificação das bactérias Herbaspirillum spp. e A. diazotrophicus mostrou não haver diferenças significativas entre os genótipos, e que, geralmente, elas estão presentes em maior número nas raízes. Enquanto Herbaspirillum spp. mantém-se mais estável ao longo do ciclo da cultura, a população de A. diazotrophicus decresce com a aproximação do final do ciclo comercial. Pode-se sugerir que as diferenças entre as taxas de FBN encontradas nos diversos genótipos não é causada por diferenças na presença ou no número das bactérias aqui estudadas.The objective of this work was to find out the localization and number of endophytic bacteria in four sugar cane genotypes and investigate upon the possible existence of correlation to the results obtained in some studies about quantification of biological nitrogen fixation (BNF. A survey of the diazotrophic bacteria present in sugar cane genotypes differing in their capacity to obtain nitrogen through BNF was performed, and population of Herbaspirillum spp. and Acetobacter diazotrophicus was quantified. The bacteria tested in the

  19. The evaluation of carrier material for increasing qualities of gel inoculum for nata de coco

    Directory of Open Access Journals (Sweden)

    RUTH MELLIAWATI

    2008-10-01

    Full Text Available Producion of nata de coco is growing fast, in line with increasing product of biocellulose demand. It is requrire a pure inoculum to reach the best biocellulose product. The aim of this reseach is to evaluate the most appropriate carrier material of gel inoculum for nata de coco. The four carrier material are Carboxy Methyl Cellulose (CMC, Agar, Sagu starch and biocellulose pap and its inoculated by Acetobacter sp. RMG-2 and A. xylinum. After inoculation, then put in the plastic bag (50 g/bag and stored in 4° C. The texture of gel, population of cell and biocellulose production were observer in 7 days. The result shown that all matterial were suitable to used as carrier for gel inoculum. Both CMC and biocellulose pap have good texture as standard qualities. Population of A. xylinum was 1.28x109 cfu/mL (in CMC carrier, 1.6x106 cfu/mL (in biocellulose pap carrier after 15 weeks. The weight of biocellulose production was 500 g/L and 740 g/L medium respectively. While the population of Acetobacter sp. RMG-2 on CMC carrier was 1.79x108 cfu/mL and 7.75x107 cfu/mL on cellulose carrier with the weight of biocellulose production 630 g/L and 775 g/L medium respectively. Thus, the carrier material (CMC and Biocellulose pap are able to keep bacteria without loss their capability to produce cellulose.

  20. 红茶菌中优势微生物的分离鉴定及系统发育分析%Isolation and Identification of Predominant Microbes from Kombucha and Phylogenic Analysis

    Institute of Scientific and Technical Information of China (English)

    乔宏萍; 沙大年; 金泰廙; 杭晓敏

    2011-01-01

    In this manuscript, , the predominant microbes were isolated from Kombucha by different medium, 8. 3 106 cfu/mL of yeasts and 1. 4 107 cfu/mL of acetic bacteria were obtained. There were 4 strains of yeasts and 2 strains of acetic bacteria through purified from different colonies. By molecular identified and phylogenic analyzed, the isolate AC1 was identified as Acetobacter - senegalensis, AC2 as Gluconacetobacter saccharivoran, Yl as Pichia membranifaciens, Y2 as Pichia galeiformis, Y3 as Dekkera anomala, Y4 as Zygosaccharomyces bailii.%采用不同的培养基对红茶菌优势微生物进行了分离,共得到酵母菌8.3×106个/mL,醋酸菌1.4×107个/mL,选取不同的菌落进行纯化后得到2株醋酸菌和4株酵母菌.经过分子生物学鉴定和系统发育树分析后,初步确定AC1为醋酸杆菌Acetobacter senegalensis,AC2为葡糖醋杆菌Gluconacetobacter saccharivorans;Y1为膜璞毕赤酵母Pichia membrani aciens,Y2为毕赤酵母Pichia galei formis,Y3为异型德克酵母Dekkera anomala,Y4为拜耳接合酵母Zygosaccharomyces bailii.

  1. 一种降低细菌纤维素分子量的方法%A Method for Reducing Bacterial Cellulose Molecular Weight

    Institute of Scientific and Technical Information of China (English)

    张名楠; 刘海芳; 李玉洁; 冯玉红

    2016-01-01

    Using coconut water as incubating system by adding galacturonic acid, bacterial cellulose (BC) were prepared by static fermentation culture method using Acetobacter xylinum which was screened in our own laboratory.The structure and performance of BC were studied.Results showed the yield of BC, water -holding performance and the thermal decomposition behavior declined, and the structure characteristics and the crystallization properties were very little difference with adding galacturonic acid, but the product molecular weight was lower, about 100000 or so, galacturonic acid instead of sucrose as carbon source can produce bacterial cellulose of low molecular weight.%以实验室自行筛选的木醋杆菌(Acetobacter xylinum)为菌种,海南椰子水为主要培养体系,在生物合成过程中向培养基中添加半乳糖醛酸,采用静态培养方法制备了细菌纤维素(BC),对 BC 的结构和性能进行了研究;结果表明:添加半乳糖醛酸后, BC 的产率、持水性能及热稳定性有所下降,而结构特征和结晶性能与不添加半乳糖醛酸的 BC 差别不大;但产物衍生化后的分子量却降低很大,约10万左右;有望用半乳糖醛酸代替蔗糖为碳源生产低分子量的细菌纤维素。

  2. 响应面法优化苹果渣生产细菌纤维素培养基及产物性能研究%Optimization of medium for bacterial cellulose fermentation with pomace by response surface methodology and property studies of the product

    Institute of Scientific and Technical Information of China (English)

    张雯; 李宏杰; 刘兰; 齐香君

    2015-01-01

    为提高木醋杆菌(Acetobacter xylinum)发酵苹果渣水解液生产细菌纤维素(Bacterial cellulose,BC)的产量,采用响应面法对发酵培养基进行优化,同时利用傅里叶红外光谱(FT-IR)和X-射线衍射(XRD)对发酵产物BC的性能和结构进行比较.单因素及响应面实验结果确定木醋杆菌(Acetobacter xylinum)发酵苹果渣水解液生产BC的最佳培养基配方为:蔗糖38.44 g、蛋白胨10.91 g、硫酸镁0.85 g、黄嘌呤0.87 g、乙醇10 mL、苹果渣水解液1000 mL、pH6.0,在此条件下BC的产量为7.19 g/L,较优化前(5.65 g/L)提高了27.3%.苹果渣水解液发酵产物BC结构性能与基本培养基发酵产物BC基本一致.说明苹果渣能够替代部分发酵原料发酵生产BC,且不影响BC性能.

  3. Isolation, identification and optimization of ethanol producing bacteria from Saccharomyces-based fermentation process of alcohol industries in Iran

    Directory of Open Access Journals (Sweden)

    Hoda Ebrahimi

    2013-01-01

    Full Text Available Introduction: Due to the vast growth of world population, consumption of a lot of energy, limited energy supply and rising prices of fuel oil in the future, other alternative energy source is essential. Ethanol is renewable and a safe fuel and it is mainly based on microbial fermentation. The purpose of this study was isolation of high ethanol producing bacteria from the fermentation process of alcohol industries and optimization of growth conditions to be introduced to the industries. Materials and methods: The samples that were collected from fermentation tanks of alcohol industries were enriched in ZSM medium. To isolate the ethanol producing bacteria, the enriched culture was transferred on RMA agar. Bacterial growth conditions and their effects on ethanol production were optimized based on pH, growth temperature, agitation, fermentation time, initial substrate concentration and carbon and nitrogen sources. In addition, the morphological, physiological and molecular characterizations were investigated for identification of the isolates.Results: Three bacterial isolates ZYM7, ZYM8 and ZYM9 were isolated from fermentation tank. All isolates were able to produce ethanol 5.00, 7.60 and 4.00 gL-1 after 48 hours, respectively. The results demonstrated that all isolates were able to consume most sugars sources specially pentose carbon xylose. The isolate ZYM7 produced 13.00 gL-1 ethanol by consumption of xylose. The results of morphological and physiological characteristics showed that ZYM7 belonged to Lactobacillus sp. and ZYM8 and ZYM9 belonged to Acetobacter sp. Moreover, 16S rRNA sequencing and phylogenetic analyses exhibited that ZYM7 was similar to Lactobacillus rhamnosus with 99% homology and ZYM8 and ZYM9 were similar to Acetobacter pasteurianus with 99 and 98% homology, respectively.Discussion and conclusion: The results showed that that the isolated bacteria were suitable candidates to produce ethanol from raw material enriched with

  4. [Comparative genomics and evolutionary analysis of CRISPR loci in acetic acid bacteria].

    Science.gov (United States)

    Kai, Xia; Xinle, Liang; Yudong, Li

    2015-12-01

    The clustered regularly interspaced short palindromic repeat (CRISPR) is a widespread adaptive immunity system that exists in most archaea and many bacteria against foreign DNA, such as phages, viruses and plasmids. In general, CRISPR system consists of direct repeat, leader, spacer and CRISPR-associated sequences. Acetic acid bacteria (AAB) play an important role in industrial fermentation of vinegar and bioelectrochemistry. To investigate the polymorphism and evolution pattern of CRISPR loci in acetic acid bacteria, bioinformatic analyses were performed on 48 species from three main genera (Acetobacter, Gluconacetobacter and Gluconobacter) with whole genome sequences available from the NCBI database. The results showed that the CRISPR system existed in 32 species of the 48 strains studied. Most of the CRISPR-Cas system in AAB belonged to type I CRISPR-Cas system (subtype E and C), but type II CRISPR-Cas system which contain cas9 gene was only found in the genus Acetobacter and Gluconacetobacter. The repeat sequences of some CRISPR were highly conserved among species from different genera, and the leader sequences of some CRISPR possessed conservative motif, which was associated with regulated promoters. Moreover, phylogenetic analysis of cas1 demonstrated that they were suitable for classification of species. The conservation of cas1 genes was associated with that of repeat sequences among different strains, suggesting they were subjected to similar functional constraints. Moreover, the number of spacer was positively correlated with the number of prophages and insertion sequences, indicating the acetic acid bacteria were continually invaded by new foreign DNA. The comparative analysis of CRISR loci in acetic acid bacteria provided the basis for investigating the molecular mechanism of different acetic acid tolerance and genome stability in acetic acid bacteria. PMID:26704949

  5. [Comparative genomics and evolutionary analysis of CRISPR loci in acetic acid bacteria].

    Science.gov (United States)

    Kai, Xia; Xinle, Liang; Yudong, Li

    2015-12-01

    The clustered regularly interspaced short palindromic repeat (CRISPR) is a widespread adaptive immunity system that exists in most archaea and many bacteria against foreign DNA, such as phages, viruses and plasmids. In general, CRISPR system consists of direct repeat, leader, spacer and CRISPR-associated sequences. Acetic acid bacteria (AAB) play an important role in industrial fermentation of vinegar and bioelectrochemistry. To investigate the polymorphism and evolution pattern of CRISPR loci in acetic acid bacteria, bioinformatic analyses were performed on 48 species from three main genera (Acetobacter, Gluconacetobacter and Gluconobacter) with whole genome sequences available from the NCBI database. The results showed that the CRISPR system existed in 32 species of the 48 strains studied. Most of the CRISPR-Cas system in AAB belonged to type I CRISPR-Cas system (subtype E and C), but type II CRISPR-Cas system which contain cas9 gene was only found in the genus Acetobacter and Gluconacetobacter. The repeat sequences of some CRISPR were highly conserved among species from different genera, and the leader sequences of some CRISPR possessed conservative motif, which was associated with regulated promoters. Moreover, phylogenetic analysis of cas1 demonstrated that they were suitable for classification of species. The conservation of cas1 genes was associated with that of repeat sequences among different strains, suggesting they were subjected to similar functional constraints. Moreover, the number of spacer was positively correlated with the number of prophages and insertion sequences, indicating the acetic acid bacteria were continually invaded by new foreign DNA. The comparative analysis of CRISR loci in acetic acid bacteria provided the basis for investigating the molecular mechanism of different acetic acid tolerance and genome stability in acetic acid bacteria.

  6. Peningkatan kualitas nata de cane dari limbah nira tebu metode Budchips dengan penambahan ekstrak tauge sebagai sumber nitrogen

    Directory of Open Access Journals (Sweden)

    NIARDA ARIFIANI

    2015-11-01

    Full Text Available Arifiani N, Sani TA, Utami AS. 2015. Improving the quality of nata de cane juice from sugar cane waste Budchips method with the addition of bean sprouts extract as nitrogen source. Bioteknologi 12: 29-33. Budchips method is a method of sugarcane cultivation in minimalist land use buds with special treatment that can produce large quantities of sugar cane segments. This method leaves of sugarcane weevil does not germinate but it still contains a lot of sugar cane juice containing sucrose and potentially as a substrate for making nata de cane. Nata is a cellulose matrix resulted from Acetobacter activity that has a chewy texture and commonly used as a food ingredient. Nata could be formed in media containing adequate of C, H, and N. Bean sprouts contain lots of protein and nitrogen sources that can support the growth of Acetobacter xylinum. The aim of this study was to determine the effect on bean sprouts extract on the quality of produced nata. The best result was shown by bean extract concentration of 300 g/500 mL of distilled water with a thickness of 0.913 mm, weighs 244.56 grams, the yield of 61.14% and 89.13% water content. Based on organoleptic test of the 30 panelists, the most preferred nata is the treatment of bean sprouts extract with the highest concentration of 300 g/500 mL of distilled water. Based on analysis of variance that sprouts extract treatment given influence on thickness, moisture content, color, flavor and texture of nata de cane.

  7. Isolation of Acetic Acid Bacteria from Sol id Fermentation Substrate of Vinegar and Analysis of Their Acid Production and Acid Tolerance Ability%醋醅中醋酸菌的分离及产酸耐酸能力分析

    Institute of Scientific and Technical Information of China (English)

    张琳; 王如福; 侯红萍; 张浩; 霍乃蕊

    2015-01-01

    以山西老陈醋正常发酵的醋醅为样品,从中分离并筛选出产酸高、耐酸能力强的醋酸菌菌株,为从微生物学角度改良食醋酿造工艺,提高产量和质量奠定基础。醋醅经富集培养,碳酸钙平板初筛,获得了14株产透明圈较大的菌株,命名为JC1~JC14,经鉴定11株为醋酸杆菌。产酸能力强的菌株,其耐酸能力也较强。测定产酸量,5株产酸能力强的菌株依次为JC 7(18.30g/L)>JC 5(15.90g/L)>JC10(13.95g/L)>JC 8(13.35g/L),这5株醋酸杆菌在发酵后期,其产酸速率基本不受影响,酸性环境反而更利于JC8产酸。筛选出的这5株醋酸菌,产酸高、耐酸强,有望用于高酸度醋的发酵生产,将其改良还可用于液态发酵生产。%Acetic acid bacteria with high acid production ability and high tolerance to acid are isolated and screened from the solid fermentation substrate of Shanxi aged vinegar, in an attempt to microbiologically modify the traditional vinegar fermentation technique,increase the yield and improve the quality.14 strains of acetic acid bacteria with larger transparent ring are selected on the CaCO3 plates and named JC1~JC14,11 strains are identified as Acetobacter by further identification.The results show that the Acetobacter with higher acid production ability also has greater tolerance to acid.5 strains produce higher amount of acid are JC7 (18.30 g/L)> JC5 (15.90 g/L)>JC10 (13.95 g/L)> JC8 (13.35 g/L)in sequence.The acid production rates of these 5 strains are not affectedeven in the late period of the fermentation tests.Acidic environment facilitates JC8 to produce more acid.These 5 strains of Acetobacter have the potential to be used in the fermentation of vinegar with high acidity;the modification can be carried out for liquid fermentation.

  8. Optimization of Extraction Conditions of Calcium Lactate by Complex-lactobacillus Based on Egg Shell Powder%用复合乳酸杆菌从鸡蛋壳粉中提取乳酸钙的条件优化

    Institute of Scientific and Technical Information of China (English)

    魏澍; 张涛; 吴和昕; 韩迎辉; 刘金玲

    2015-01-01

    为加大对废弃蛋壳的资源利用率,提高从蛋壳中提取乳酸钙的产能,将定量的蛋壳粉加入保加利亚乳酸杆菌和醋酸杆菌的复合乳酸菌发酵液中,采用甲基百里香酚蓝微板吸光法测定发酵液中两种复合乳酸菌在不同浓度、不同添加比例、不同发酵酸碱度和不同添加物条件下波长610nm的OD值,并结合钙转化公式计算各试验组乳酸钙含量和乳酸钙的转化率。结果表明:当保加利亚乳酸杆菌和醋酸杆菌在浓度为6×108•mL-1、体积比为1:3时,钙的转化率为75.38%,高于其他实验组;而当复合乳酸菌发酵液中pH值为6时,钙的转化率达到最高,为75.12%;各种糖底物添加试验结果表明:2%甘露醇对保加利亚乳酸杆菌和醋酸杆菌糖反应活性增强效果较为明显,说明菌液中的复合菌比例、添加糖的种类及初始pH值能够影响保加利亚乳酸杆菌和醋酸杆菌对蛋壳粉的发酵分解率。%In order to increase the resource utilization of waste eggshell and to promote the production of calcium lactate by complex-lactobacillus based on egg shell powder, the fermentation conditions including the concentration and proportion of lactic acid bacteria, pH, and environmental additives were optimized by the comparative experiments using methyl thymol rebounds absorption method via absorbance values 610. Test results showed that the calcium conversion rate was 75.38% higher than other groups as Lactobacillus bulgaricus: Acetobacter spp = 1:3 with the concentration of 6 ×108•mL-1, and the calcium conversion rate was 75.12% reaching the highest when pH was at 6. The results further indicated that the mannitol could obviously enhance the sugar reactivity of Lactobacillus bulgaricus and Acetobacter spp. These results manifested that the proportion of complex bacteria, sugar and initial pH had a major impact on the fermentation of Lactobacillus bulgaricus and Acetobacter spp

  9. 乙醇脱氢酶(ADH)产酶菌株的选育%Breeding of Alcohol Dehydrogenase Producing Strains

    Institute of Scientific and Technical Information of China (English)

    问清江; 慕娟; 党永; 张烁; 景振龙; 贺聪莹; 颜阳欣

    2013-01-01

    185 alcohol dehydrogenase ( ADH ) producing strains were isolated from samples collected from vinegar fermented grains in vinegar production enterprise by selective medium using ethanol as the sole carbon source, and calcium carbonate transparent circle on plate. 20 high ADH producing strains were bred under shaking-flask fermenta-tion, in which acid output and ethanol tolerance were used as standards. The acid output of A5-2 achieved 49. 85 g/L and its capacity of ethanol tolerance was strong. A5-2 was initially identified as Acetobacter pasteurianus based on its morphological characterization and 16S rDNA sequence. Study on enzyme characteristics showed that the optimal reac-tion conditions of A5-2 ADH were at 45 ℃ and pH 4. 0, and it had heat tolerance and fine tolerance against acid-base. The preparation condition of crude ADH were saturated concentration of ammonium sulfate was at 70% ~ 80%and the ADH activity recovery was at 84%.%从食醋生产企业的醋醅中采集样品,以乙醇为唯一碳源,用碳酸钙透明圈平板法分离出185株菌株,然后以产酸量和耐乙醇能力为标准,瓶发酵选育出20株ADH产酶菌株;A5-2产酸量为49.85 g/L,耐乙醇能力强,A5-2的菌种形态学和16S rDNA序列分析初步鉴定为巴斯德醋酸杆菌( Acetobacter pasteurianus);A5-2乙醇脱氢酶酶学性质研究表明:最适作用温度和pH分别为45℃和pH 4.0,具有一定的耐热性和良好的耐酸碱性;A5-2乙醇脱氢酶粗酶制备条件为硫酸铵饱和度70%~80%,回收率84%。

  10. Study of Process for Bacterial Cellulose Fermentation with Pomace and Properties of the Product%利用苹果渣发酵生产细菌纤维素工艺及产物性能研究

    Institute of Scientific and Technical Information of China (English)

    张雯; 葛万云; 齐香君

    2015-01-01

    In order to increase the producing efficiency of bacterial cellulose (BC )fermented by Acetobacter xylinum using pomace, single factor and orthogonal experiments were used to optimize the hydrolysis process of pomace. Meanwhile, the properties of BC were compared through fourier transform infrared (FT-IR) and X-ray diffraction (XRD). According to the results of experiments, the optimal hydrolysis process were determined as follows: liquid-solid ratio 4 mL/g, dosage of celluclast 16.8 EGU/g, pH5.5, hydrolytic temperature 55 ℃, hydrolytic time 40 h. Under these conditions, the productive rate of reducing sugar was 38.02%. The properties and structures of BC produced with pomace hydrolysate were confirmed to be basically same with BC produced with basic medium, which indicated that the pomace hydrolysate could be used as part of raw materials to ferment BC and would not affect the properties of BC.%为提高木醋杆菌(Acetobacter xylinum)发酵苹果渣生产细菌纤维素(Bacterial cellulose,BC)的生产效率,采用单因素及正交实验对纤维素酶水解苹果渣工艺进行优化,同时利用傅里叶红外光谱(FT-IR)和X-射线衍射(XRD)对发酵产物BC的性能和结构进行比较.单因素及响应面实验结果确定苹果渣最优水解工艺:液固比4 mL/g,酶用量16.8 EGU/g,pH5.5,水解温度55℃,水解时间40 h.此条件下,苹果渣水解产生还原糖产率为38.02%.苹果渣水解液发酵产物BC结构性能与基本培养基发酵产物BC基本一致. 研究结果表明苹果渣能够作为发酵原料发酵生产BC,且不影响BC性能.

  11. Avaliação da resposta inflamatória traqueal ao curativo de celulose bacteriana após escarificação cirúrgica em coelhos Tracheal inflammatory response to bacterial cellulose dressing after surgical scarification in rabbits

    Directory of Open Access Journals (Sweden)

    Angelo D'urso Panerari

    2008-08-01

    Full Text Available Dentre as causas de insucesso nas cirurgias para a estenose traqueal está a formação de tecidos de cicatrização exuberantes. O uso de curativos para evitar esta reação pode ser de grande valia nestes casos. A celulose bacteriana produzida por acetobacter xylinun pode ser útil nestes casos. Não há estudos na região laringotraqueal. OBJETIVO: Avaliar a resposta tecidual subglótica de coelhos após escarificação e colocação de curativo de celulose, comparando com grupo controle. FORMA DE ESTUDO: Experimental MATERIAL E MÉTODOS: Foram estudados 26 coelhos, submetidos a escarificação da região laringotraqueal e tratados com curativo e comparados com controle. Foram estabelecidos 4 tempos de seguimento. Os seguimentos laringotraqueais foram examinados histologicamente e os resultados foram avaliados estaticamente. RESULTADOS: O grupo de estudo evoluiu com o passar do tempo com resultados estatisticamente semelhantes ao do grupo controle, nos parâmetros Congestão vascular, Exsudato purulento, Inflamação aguda, Integridade do epitélio, Proliferação fibrosa e Reação granulomatosa. CONCLUSÃO: Não foram observadas diferenças entre os grupos controle e de estudo quanto aos parâmetros inflamatórios ou cicatriciais. Não houve sinais inflamatórios relacionados ao uso da membrana de celulose que não tivessem ocorrido devido ao traumatismo cirúrgico.Exuberant scarring tissue formation is among the failure causes of tracheal stenosis surgery. Dressings that could avoid such reaction could be very helpful in these cases. Bacterial cellulose, produced by acetobacter xylinun can be useful in these cases. There are no studies in the laryngotracheal region. AIM: to assess subglottic tissue response in rabbits after scarification and placement of cellulose dressing, and comparing it to a control group. STUDY DESIGN: experimental. MATERIALS AND METHODS: 26 rabbits underwent laryngotracheal scarification, received the dressing and

  12. 实时荧光定量PCR监测镇江香醋醋酸发酵过程中微生物变化%Detection of the variation of microorganisms in acetic acid fermentation of Zhenjiang aromatic vinegar through real-time quantitative PCR

    Institute of Scientific and Technical Information of China (English)

    陶京兰; 陆震鸣; 王宗敏; 李国权; 史劲松; 许正宏

    2013-01-01

    对镇江香醋醋酸发酵阶段醋醅中功能微生物的变化进行定量分析.建立了实时荧光定量PCR方法,对醋酸发酵阶段醋醅中总细菌、总真菌、醋酸菌、乳酸菌和酵母的动态变化进行了定量分析.研究结果表明,发酵起始阶段(1~7天)醋醅中总细菌、醋酸菌和乳酸菌的生物量快速上升,分别于第6、7、4天达到最大值,为4.85 ×1011,1.14×1010和3.37 ×1011copies/g干醅.随后各类细菌的生物量逐渐下降,并维持在一定水平.醋醅中总真菌和酵母的生物量在发酵前期变化不大,7天后至发酵结束总真菌的生物量逐渐下降为7.59×104 copies/g干醅,而酵母生物量则在发酵8~12天内下降为0.%Variation of the functional microbes was quantitatively analyzed during the acetic acid fermentation process of Zhenjiang aromatic vinegar.Real-time quantitative PCR (RT-qPCR) was applied to quantitatively analyze the variation of bacteria, fungi, Acetobacter, Lactobacillus and Saccharomyces during the acetic acid fermentation process in this study.Results showed that the biomass of bacteria, Acetobacter and Lactobacillus increased rapidly in the initial stage of fermentation (day 1 ~7) , and reached the maximum on the 6th, 7th and 4th day with the biomass were 3.37×1011 , 1.14×1010 and 3.37×1011 copies/g dry grains respectively, which followed by a gradually decent to a certain level with the fermentation performed.The biomass of fungi and Saccharomyces showed little change in the initial stage of fermentation, while the biomass of fungi decreased gradually to 7.59×104 copies/g dry grains from day 7 to day 18 , and the biomass of Saccharomyces decreased rapidly to zero from day 8 to day 12.

  13. Optimization of immobilization of acetic acid bacteria for ginseng vinegar drinks%固定化醋酸菌发酵人参醋饮料加工工艺优化

    Institute of Scientific and Technical Information of China (English)

    徐璐; 文连奎

    2012-01-01

    After studying the alcohol fermentation,acetic fermentation by immobilized acetobacter,clarification, and blending to ginseng vinegar drinks with ginseng. The result showed that..when 3g of sawdust and 20mL of adsorption vinegar mother were added in 100mL ginseng alcohol and the fermentation temperature was 28℃, the fermentation was fastest,and the immobilized acetobacter could be recycled. The gelatin-tannin clarify showed the better effect,the transmittance was 87.8% with the 0.02‰ content of vinegar. The best formula conditions for ginseng vinegar drinks was that ginseng original vinegar 7% ,jujube juice concentrate 1% ,total acid 0.37% ,total sugar 12% and the product was amber with characteristic flavor of ginseng and vinegar and the score was 90.%摘要:以生晒人参为原料,经酒精发酵后通过固定化醋酸茵进行醋酸发酵、澄清及调配得到人参醋饮料。通过正交实验分别确定固定化发酵最佳条件、人参醋饮料最佳配方,通过离心、壳聚糖、明胶一单宁梯度澄清实验确定澄清方法。实验结果表明,每100mL人参发酵酒中,木屑3g、被吸附醋母20mL、28℃时发酵速度最快,同时固定化醋酸菌可重复利用:采用明胶一单宁澄清法澄清效果最佳,明胶、单宁添加量各为0.02‰,透光率达87.8%;人参醋饮料最佳配方为:人参原醋7%、浓缩大枣汁1%、总酸0.37%、总糖12%,感官评分为90分,产品口感最佳。

  14. VARIETY OF MICROORGANISMS GROUPS LIVING ON BERRIES OF GRAPES

    Directory of Open Access Journals (Sweden)

    Ageeva N. M.

    2015-09-01

    Candida. In the microflora of Cabernets, Risling and, especially, Karaburnu grapes, we have found lactic acid bacteria Lactobacillus plantarum and Lactobacillus brevis. Lactobacillus plantarum. Among the bacteria the total quantity of coccic flora composes - 56 %, the rod-shaped - 44 %. Two types of active acetous bacteria are identified – Acetobacter aceti and Acetobacter xelinum. Especially high was their surface concentration on the berries of Kachich type of grapes

  15. 从水果中分离醋酸菌制备苹果梨醋的研究白龙律1,武伦鹏2,宋鉴达1,刘洪亮1,朴文香3%Research on Preparation of AppIe-Pear Vinegar with Acetic Acid Bacteria IsoIated from Fruits

    Institute of Scientific and Technical Information of China (English)

    白龙律; 武伦鹏; 宋鉴达; 刘洪亮; 朴文香

    2015-01-01

    从11种常见水果样品中分离培养得到38种醋酸菌,利用乙醇浓度、菌株接种量、发酵液有效体积三个条件的正交实验,进一步筛选出高效菌株,并在优化的条件下制备苹果梨醋。最终得到一种醋酸产量高的高效菌株Ace22,通过分子生物学鉴定得知,菌株Ace22属于醋酸杆菌属(Acetobacter)。%In this study,38 acetic acid bacteria are isolated from 11 kinds of fruits .The effects of ethanol concentration,inoculation amount,and effective volume of fermentation broth on acetic acid bacteria fermentation are investigated, and apple-pear vinegar is prepared under optimized fermentation conditions.Finally,a high-yield acetic acid strain Ace22 is selected,it is learned that the strain Ace22 belongs to Acetobacter by molecular biology identification.

  16. The Occurrence of Beer Spoilage Lactic Acid Bacteria in Craft Beer Production.

    Science.gov (United States)

    Garofalo, Cristiana; Osimani, Andrea; Milanović, Vesna; Taccari, Manuela; Aquilanti, Lucia; Clementi, Francesca

    2015-12-01

    Beer is one of the world's most ancient and widely consumed fermented alcoholic beverages produced with water, malted cereal grains (generally barley and wheat), hops, and yeast. Beer is considered an unfavorable substrate of growth for many microorganisms, however, there are a limited number of bacteria and yeasts, which are capable of growth and may spoil beer especially if it is not pasteurized or sterile-filtered as craft beer. The aim of this research study was to track beer spoilage lactic acid bacteria (LAB) inside a brewery and during the craft beer production process. To that end, indoor air and work surface samples, collected in the brewery under study, together with commercial active dry yeasts, exhausted yeasts, yeast pellet (obtained after mature beer centrifugation), and spoiled beers were analyzed through culture-dependent methods and PCR-DGGE in order to identify the contaminant LAB species and the source of contamination. Lactobacillus brevis was detected in a spoiled beer and in a commercial active dry yeast. Other LAB species and bacteria ascribed to Staphylococcus sp., Enterobaceriaceae, and Acetobacter sp. were found in the brewery. In conclusion, the PCR-DGGE technique coupled with the culture-dependent method was found to be a useful tool for identifying the beer spoilage bacteria and the source of contamination. The analyses carried out on raw materials, by-products, final products, and the brewery were useful for implementing a sanitization plan to be adopted in the production plant.

  17. Encapsulation of Platelet in Kefiran Polymer and Detection of Bioavailability of Immobilized Platelet in Probiotic Kefiran as A New Drug for Surface Bleeding

    Directory of Open Access Journals (Sweden)

    Anahita Jenab

    2015-11-01

    Full Text Available Background : Kefir contains lactic acid bacteria (Lactobacillus, Lactococcus, Leuconostoc, Acetobacter and Streptococcus and yeasts (Kluyveromyces, Torula, Candida, Saccharomyces .Kefiran is the polysaccharide produced by lactic acid bacteria in kefir.Methods : Kefiran was prepared from milk containing 0.5% fat and 10 grams kefir grains and was separated from kefir by ethanol (0.02 gram following entrapping the platelets to this polymer. Ligand of the platelet-polysaccharide was studied by FTIR.Results : FTIR results showed that the bands of C-O and C-O-C connections were formed and the polysaccharides had been attached to the receptors of the platelet glycoproteins (GP Ib,GPIIb / IIIa. Stability and encapsulation of the platelet and kefiran were assessed by Coulter Counter. Encapsulation of the platelets by polysaccharide at the beginning caused to reduce the number of platelets following by releasing of 50% of the platelets after 3 hours.Conclusion : The platelets were encapsulated in kefiran polymer and detected for bioavailability as new drug for surface bleeding. Also, kefiran has antimicrobial and antifungal properties. On the other hand, the existence of nisin in kefiran could be useful as an antibacterial lantibiotic. 

  18. Investigation the Effects of Different Doses Organic Fertilizers and Phosphate Solubilizing Bacterias on Yield and Nutrient Contents in Chickpea (Cicer arietinum L.

    Directory of Open Access Journals (Sweden)

    Ferit SÖNMEZ

    2015-07-01

    Full Text Available The study was conducted to determine the effect of phosphate solubilizing bacteria (N2; Bacillus megaterium M-3, TV-6I; Cellulosimicrobium cellulans, TV-34A; Hafnia Alve, TV-69E; Acetobacter pasteurianus and TV-83F; Bacillus cereus and organic fertilizer (0, 10 and 20 ton / ha on the seed yield and nutrient content of chickpea under field conditions in 2010 and 2011 growing seasons. Phosphate solubilizing bacteria used in this study were determined by the separate investigation conducted in chamber room by using ten phosphate solubilizing bacteria and organic fertilizer (control, %5,%10. The tiral were laid out with a factorial design in randomized complete block with three replications. In this study, plant height, primary branches, secondary branches and number of pods per plant, number of seeds per pod, grain yield and biological yield and nutrient content of stem and seed were determined. According to the results of the study bacteria applications increased significantly biological and seed yield. Bacteria applications without organic fertilizer increased nutrient contents of seed and steed except cupper content. In case of inoculation with organic fertilizer provided more increases in biological and seed yields. The highest seed yield were obtained from application of 20 ton/ha + N2 (Bacillus megaterium M-3 with 1020 kg/ha and 1793 kg/ha in 2010 and 2011 years, respectively. Bacteria without organic fertilizer application were more active in terms of phosphorus uptake in both years. 

  19. Yeasts are essential for cocoa bean fermentation.

    Science.gov (United States)

    Ho, Van Thi Thuy; Zhao, Jian; Fleet, Graham

    2014-03-17

    Cocoa beans (Theobroma cacao) are the major raw material for chocolate production and fermentation of the beans is essential for the development of chocolate flavor precursors. In this study, a novel approach was used to determine the role of yeasts in cocoa fermentation and their contribution to chocolate quality. Cocoa bean fermentations were conducted with the addition of 200ppm Natamycin to inhibit the growth of yeasts, and the resultant microbial ecology and metabolism, bean chemistry and chocolate quality were compared with those of normal (control) fermentations. The yeasts Hanseniaspora guilliermondii, Pichia kudriavzevii and Kluyveromyces marxianus, the lactic acid bacteria Lactobacillus plantarum and Lactobacillus fermentum and the acetic acid bacteria Acetobacter pasteurianus and Gluconobacter frateurii were the major species found in the control fermentation. In fermentations with the presence of Natamycin, the same bacterial species grew but yeast growth was inhibited. Physical and chemical analyses showed that beans fermented without yeasts had increased shell content, lower production of ethanol, higher alcohols and esters throughout fermentation and lesser presence of pyrazines in the roasted product. Quality tests revealed that beans fermented without yeasts were purplish-violet in color and not fully brown, and chocolate prepared from these beans tasted more acid and lacked characteristic chocolate flavor. Beans fermented with yeast growth were fully brown in color and gave chocolate with typical characters which were clearly preferred by sensory panels. Our findings demonstrate that yeast growth and activity were essential for cocoa bean fermentation and the development of chocolate characteristics.

  20. Comparative evaluation of the genomes of three common Drosophila-associated bacteria.

    Science.gov (United States)

    Petkau, Kristina; Fast, David; Duggal, Aashna; Foley, Edan

    2016-09-15

    Drosophila melanogaster is an excellent model to explore the molecular exchanges that occur between an animal intestine and associated microbes. Previous studies in Drosophila uncovered a sophisticated web of host responses to intestinal bacteria. The outcomes of these responses define critical events in the host, such as the establishment of immune responses, access to nutrients, and the rate of larval development. Despite our steady march towards illuminating the host machinery that responds to bacterial presence in the gut, there are significant gaps in our understanding of the microbial products that influence bacterial association with a fly host. We sequenced and characterized the genomes of three common Drosophila-associated microbes: Lactobacillus plantarum, Lactobacillus brevis and Acetobacter pasteurianus For each species, we compared the genomes of Drosophila-associated strains to the genomes of strains isolated from alternative sources. We found that environmental Lactobacillus strains readily associated with adult Drosophila and were similar to fly isolates in terms of genome organization. In contrast, we identified a strain of A. pasteurianus that apparently fails to associate with adult Drosophila due to an inability to grow on fly nutrient food. Comparisons between association competent and incompetent A. pasteurianus strains identified a short list of candidate genes that may contribute to survival on fly medium. Many of the gene products unique to fly-associated strains have established roles in the stabilization of host-microbe interactions. These data add to a growing body of literature that examines the microbial perspective of host-microbe relationships.

  1. Overview on mechanisms of acetic acid resistance in acetic acid bacteria.

    Science.gov (United States)

    Wang, Bin; Shao, Yanchun; Chen, Fusheng

    2015-02-01

    Acetic acid bacteria (AAB) are a group of gram-negative or gram-variable bacteria which possess an obligate aerobic property with oxygen as the terminal electron acceptor, meanwhile transform ethanol and sugar to corresponding aldehydes, ketones and organic acids. Since the first genus Acetobacter of AAB was established in 1898, 16 AAB genera have been recorded so far. As the main producer of a world-wide condiment, vinegar, AAB have evolved an elegant adaptive system that enables them to survive and produce a high concentration of acetic acid. Some researches and reviews focused on mechanisms of acid resistance in enteric bacteria and made the mechanisms thoroughly understood, while a few investigations did in AAB. As the related technologies with proteome, transcriptome and genome were rapidly developed and applied to AAB research, some plausible mechanisms conferring acetic acid resistance in some AAB strains have been published. In this review, the related mechanisms of AAB against acetic acid with acetic acid assimilation, transportation systems, cell morphology and membrane compositions, adaptation response, and fermentation conditions will be described. Finally, a framework for future research for anti-acid AAB will be provided.

  2. Acetic acid bacteria in traditional balsamic vinegar: phenotypic traits relevant for starter cultures selection.

    Science.gov (United States)

    Gullo, Maria; Giudici, Paolo

    2008-06-30

    This review focuses on acetic acid bacteria in traditional balsamic vinegar process. Although several studies are available on acetic acid bacteria ecology, metabolism and nutritional requirements, their activity as well as their technological traits in homemade vinegars as traditional balsamic vinegar is not well known. The basic technology to oxidise cooked grape must to produce traditional balsamic vinegar is performed by the so called "seed-vinegar" that is a microbiologically undefined starter culture obtained from spontaneous acetification of previous raw material. Selected starter cultures are the main technological improvement in order to innovate traditional balsamic vinegar production but until now they are rarely applied. To develop acetic acid bacteria starter cultures, selection criteria have to take in account composition of raw material, acetic acid bacteria metabolic activities, applied technology and desired characteristics of the final product. For traditional balsamic vinegar, significative phenotypical traits of acetic acid bacteria have been highlighted. Basic traits are: ethanol preferred and efficient oxidation, fast rate of acetic acid production, tolerance to high concentration of acetic acid, no overoxidation and low pH resistance. Specific traits are tolerance to high sugar concentration and to a wide temperature range. Gluconacetobacter europaeus and Acetobacter malorum strains can be evaluated to develop selected starter cultures since they show one or more suitable characters. PMID:18177968

  3. Comparative evaluation of the genomes of three common Drosophila-associated bacteria.

    Science.gov (United States)

    Petkau, Kristina; Fast, David; Duggal, Aashna; Foley, Edan

    2016-01-01

    Drosophila melanogaster is an excellent model to explore the molecular exchanges that occur between an animal intestine and associated microbes. Previous studies in Drosophila uncovered a sophisticated web of host responses to intestinal bacteria. The outcomes of these responses define critical events in the host, such as the establishment of immune responses, access to nutrients, and the rate of larval development. Despite our steady march towards illuminating the host machinery that responds to bacterial presence in the gut, there are significant gaps in our understanding of the microbial products that influence bacterial association with a fly host. We sequenced and characterized the genomes of three common Drosophila-associated microbes: Lactobacillus plantarum, Lactobacillus brevis and Acetobacter pasteurianus For each species, we compared the genomes of Drosophila-associated strains to the genomes of strains isolated from alternative sources. We found that environmental Lactobacillus strains readily associated with adult Drosophila and were similar to fly isolates in terms of genome organization. In contrast, we identified a strain of A. pasteurianus that apparently fails to associate with adult Drosophila due to an inability to grow on fly nutrient food. Comparisons between association competent and incompetent A. pasteurianus strains identified a short list of candidate genes that may contribute to survival on fly medium. Many of the gene products unique to fly-associated strains have established roles in the stabilization of host-microbe interactions. These data add to a growing body of literature that examines the microbial perspective of host-microbe relationships. PMID:27493201

  4. The Occurrence of Beer Spoilage Lactic Acid Bacteria in Craft Beer Production.

    Science.gov (United States)

    Garofalo, Cristiana; Osimani, Andrea; Milanović, Vesna; Taccari, Manuela; Aquilanti, Lucia; Clementi, Francesca

    2015-12-01

    Beer is one of the world's most ancient and widely consumed fermented alcoholic beverages produced with water, malted cereal grains (generally barley and wheat), hops, and yeast. Beer is considered an unfavorable substrate of growth for many microorganisms, however, there are a limited number of bacteria and yeasts, which are capable of growth and may spoil beer especially if it is not pasteurized or sterile-filtered as craft beer. The aim of this research study was to track beer spoilage lactic acid bacteria (LAB) inside a brewery and during the craft beer production process. To that end, indoor air and work surface samples, collected in the brewery under study, together with commercial active dry yeasts, exhausted yeasts, yeast pellet (obtained after mature beer centrifugation), and spoiled beers were analyzed through culture-dependent methods and PCR-DGGE in order to identify the contaminant LAB species and the source of contamination. Lactobacillus brevis was detected in a spoiled beer and in a commercial active dry yeast. Other LAB species and bacteria ascribed to Staphylococcus sp., Enterobaceriaceae, and Acetobacter sp. were found in the brewery. In conclusion, the PCR-DGGE technique coupled with the culture-dependent method was found to be a useful tool for identifying the beer spoilage bacteria and the source of contamination. The analyses carried out on raw materials, by-products, final products, and the brewery were useful for implementing a sanitization plan to be adopted in the production plant. PMID:26489032

  5. Antibacterial activity of hen egg white lysozyme modified by heat and enzymatic treatments against oenological lactic acid bacteria and acetic acid bacteria.

    Science.gov (United States)

    Carrillo, W; García-Ruiz, A; Recio, I; Moreno-Arribas, M V

    2014-10-01

    The antimicrobial activity of heat-denatured and hydrolyzed hen egg white lysozyme against oenological lactic acid and acetic acid bacteria was investigated. The lysozyme was denatured by heating, and native and heat-denatured lysozymes were hydrolyzed by pepsin. The lytic activity against Micrococcus lysodeikticus of heat-denatured lysozyme decreased with the temperature of the heat treatment, whereas the hydrolyzed lysozyme had no enzymatic activity. Heat-denatured and hydrolyzed lysozyme preparations showed antimicrobial activity against acetic acid bacteria. Lysozyme heated at 90°C exerted potent activity against Acetobacter aceti CIAL-106 and Gluconobacter oxydans CIAL-107 with concentrations required to obtain 50% inhibition of growth (IC50) of 0.089 and 0.013 mg/ml, respectively. This preparation also demonstrated activity against Lactobacillus casei CIAL-52 and Oenococcus oeni CIAL-91 (IC50, 1.37 and 0.45 mg/ml, respectively). The two hydrolysates from native and heat-denatured lysozyme were active against O. oeni CIAL-96 (IC50, 2.77 and 0.3 mg/ml, respectively). The results obtained suggest that thermal and enzymatic treatments increase the antibacterial spectrum of hen egg white lysozyme in relation to oenological microorganisms.

  6. Microbes Associated with Freshly Prepared Juices of Citrus and Carrots

    Directory of Open Access Journals (Sweden)

    Kamal Rai Aneja

    2014-01-01

    Full Text Available Fruit juices are popular drinks as they contain antioxidants, vitamins, and minerals that are essential for human being and play important role in the prevention of heart diseases, cancer, and diabetes. They contain essential nutrients which support the growth of acid tolerant bacteria, yeasts, and moulds. In the present study, we have conducted a microbiological examination of freshly prepared juices (sweet lime, orange, and carrot by serial dilution agar plate technique. A total of 30 juice samples were examined for their microbiological quality. Twenty-five microbial species including 9 bacterial isolates, 5 yeast isolates, and 11 mould isolates were isolated from juices. Yeasts and moulds were the main cause of spoilage of juices. Aspergillus flavus and Rhodotorula mucilaginosa were observed in the maximum number of juice samples. Among bacteria Bacillus cereus and Serratia were dominant. Escherichia coli and Staphylococcus aureus were detected in few samples. Candida sp., Curvularia, Colletotrichum, and Acetobacter were observed only in citrus juice samples. Alternaria, Aspergillus terreus, A. niger, Cladosporium, and Fusarium were also observed in tested juice samples. Some of the microorganisms detected in these juice samples can cause disease in human beings, so there is need for some guidelines that can improve the quality of fruit juices.

  7. Brazilian kefir: structure, microbial communities and chemical composition

    Directory of Open Access Journals (Sweden)

    Karina Teixeira Magalhães

    2011-06-01

    Full Text Available Microbial ecology and chemical composition of Brazilian kefir beverage was performed. The microorganisms associated with Brazilian kefir were investigated using a combination of phenotypic and genotypic methods. A total of 359 microbial isolates were identified. Lactic acid bacteria (60.5% were the major isolated group identified, followed by yeasts (30.6% and acetic acid bacteria (8.9%. Lactobacillus paracasei (89 isolates, Lactobacillus parabuchneri (41 isolates, Lactobacillus casei (32 isolates, Lactobacillus kefiri (31 isolates, Lactococcus lactis (24 isolates, Acetobacter lovaniensis (32 isolates, Kluyveromyces lactis (31 isolates, Kazachstania aerobia (23 isolates, Saccharomyces cerevisiae (41 isolates and Lachancea meyersii (15 isolates were the microbial species isolated. Scanning electron microscopy showed that the microbiota was dominated by bacilli (short and curved long cells growing in close association with lemon-shaped yeasts cells. During the 24 h of fermentation, the protein content increased, while lactose and fat content decreased. The concentration of lactic acid ranged from 1.4 to 17.4 mg/ml, and that of acetic acid increased from 2.1 to 2.73 mg/ml. The production of ethanol was limited, reaching a final mean value of 0.5 mg/ml.

  8. Purification and enzymic properties of the fructosyltransferase of Streptococcus salivarius ATCC 25975.

    Science.gov (United States)

    Song, D D; Jacques, N A

    1999-01-01

    The recombinant fructosyltransferase (Ftf) of Streptococcus salivarius was expressed in Escherichia coli and purified to electrophoretic homogeneity after a combination of adsorption, ion-exchange and gel-filtration chromatography. The N-terminal signal sequence of the Ftf was removed by E. coli at the same site as in its natural host. The purified Ftf exhibited maximum activity at pH 6.0 and 37 degrees C, was activated by Ca2+, but inhibited by the metal ions Cu2+, Zn2+, Hg2+ and Fe3+. The enzyme catalysed the transfer of the fructosyl moiety of sucrose to a number of acceptors, including water, glucose and sucrose via a Ping Pong mechanism involving a fructosyl-enzyme intermediate. While this mechanism of catalysis is utilized by the levansucrases of Bacillus subtilis and Acetobacter diazotrophicus and the values of the kinetic constants for the three enzymes are similar, sucrose was a far more efficient fructosyl-acceptor for the Ftf of S. salivarius than for the two other enzymes. PMID:10393084

  9. In-vitro Degradation Behaviour of Irradiated Bacterial Cellulose Membrane

    International Nuclear Information System (INIS)

    Bacterial cellulose membrane synthesized by Acetobacter xylinum in coconut water medium has potential application for Guided bone Regeneration. However, this membrane may not meet some application requirements due to its low biodegradation properties. In this paper, incorporation of gamma irradiation into the membrane is a developed strategy to increase its biodegradability properties. The in-vitro degradation study in synthetic body fluid (SBF) of the irradiated membrane has been analyzed during periods of 6 months by means of weight loss, mechanical properties and scanning electron microscopy observation compared to that the un-irradiated one. The result showed that weight loss of irradiated membrane with 25 kGy and 50 kGy and immersed in SBF solution for 6 months reached 18% and 25% respectively. While un-irradiated membrane did not give significant weight loss. Tensile strength of membranes decreases with increasing of irradiation dose and further decreases in tensile strength is observed when irradiated membrane was followed by immersion in SBF solution. Microscope electron image of cellulose membranes shows that un-irradiated bacterial cellulose membrane consists of dense ultrafine fibril network structures, while irradiation result in cleavage of fibrils network of cellulose. The fibrils network become loosely after irradiated membrane immersed in SBF solution due to released of small molecular weight carbohydrates formed during by irradiation from the structure (author)

  10. The biological and toxicological importance of molybdenum in the environment and in the nutrition of plants, animals and man. Part 1: Molybdenum in plants.

    Science.gov (United States)

    Anke, M; Seifert, M

    2007-09-01

    In 1930, Bortels showed that molybdenum is necessary for nitrogen fixation in Acetobacter, and in 1939 Arnon and Stout reported that molybdenum is essential for life in higher plants. Nitrogenase is the nitrogen-fixing enzyme complex, while nitrate reductase requires molybdenum for its activity. Molybdenum occurs in the earth crust with an abundance of 1.0-1.4 mg/kg. The molybdenum content of the vegetation is determined by the amount of this element in the soil and its pH-value. The weathering soils of granite, porphyry, gneiss and Rotliegendes produce a molybdenum-rich vegetation. Significantly poorer in Mo is the vegetation on loess, diluvial sands, alluvial riverside soils and especially on Keuper and Muschelkalk weathering soils, which produce legumes and, e.g. cauliflower with molybdenum deficiency symptoms. The molybdenum content of the flora decreases with increasing age. Legumes store the highest molybdenum levels in the bulbs of their roots; on average, they accumulate more molybdenum than herbs and grasses do. The danger of molybdenum toxicity in plants is small. PMID:17899788

  11. Bacterial Cellulose-Binding Domain Modulates in Vitro Elongation of Different Plant Cells1

    Science.gov (United States)

    Shpigel, Etai; Roiz, Levava; Goren, Raphael; Shoseyov, Oded

    1998-01-01

    Recombinant cellulose-binding domain (CBD) derived from the cellulolytic bacterium Clostridium cellulovorans was found to modulate the elongation of different plant cells in vitro. In peach (Prunus persica L.) pollen tubes, maximum elongation was observed at 50 μg mL−1 CBD. Pollen tube staining with calcofluor showed a loss of crystallinity in the tip zone of CBD-treated pollen tubes. At low concentrations CBD enhanced elongation of Arabidopsis roots. At high concentrations CBD dramatically inhibited root elongation in a dose-responsive manner. Maximum effect on root hair elongation was at 100 μg mL−1, whereas root elongation was inhibited at that concentration. CBD was found to compete with xyloglucan for binding to cellulose when CBD was added first to the cellulose, before the addition of xyloglucan. When Acetobacter xylinum L. was used as a model system, CBD was found to increase the rate of cellulose synthase in a dose-responsive manner, up to 5-fold compared with the control. Electron microscopy examination of the cellulose ribbons produced by A. xylinum showed that CBD treatment resulted in a splayed ribbon composed of separate fibrillar subunits, compared with a thin, uniform ribbon in the control. PMID:9701575

  12. Evolution of sourdough microbiota in spontaneous sourdoughs started with different plant materials.

    Science.gov (United States)

    Ripari, Valery; Gänzle, Michael G; Berardi, Enrico

    2016-09-01

    The preparation of sourdough in bakeries may include the use of inocula, e.g. fruits, flowers or rumen cuts to accelerate the process of selection of suitable microorganisms. The aim of this work was to investigate the effect of these inocula on the microbial evolution in sourdoughs. First, the microbiota of nineteen traditional sourdoughs that were initially started with diverse inocula was identified. Second, de novo sourdoughs were started with plant materials and the evolution of sourdough microbiota was investigated by culture, and by high-resolution melting curve quantitative PCR (HRM-qPCR). This study developed a new protocol for HRM-qPCR analysis of yeast microbiota in sourdough, and indicates this independent culture method suitable for characterization of yeasts. Microbiota of traditional sourdoughs were largely independent from the use of inoculum, however, Acetobacter spp. were identified only in sourdoughs started with apple flowers or apple pulp. In de novo sourdoughs started with plant materials, microbiota rapidly stabilized, and were characterized by Lactobacillus sanfranciscensis, Lactobacillus plantarum, Lactobacillus graminis, or Lactobacillus rossiae, and Saccharomyces cerevisiae as dominant species. Competition experiments revealed that the ecological fitness of L. plantarum, L. graminis, and L. rossiae in wheat or rye malt sourdoughs was lower when compared to L. sanfranciscensis, demonstrating that their presence in de novo sourdoughs reflects dispersal limitation. In conclusion, establishment of microbiota in de novo sourdoughs is dispersal limited. This study provides scientific support for the artisanal practice to inoculate de novo sourdoughs with flowers, berries, or related plant material. PMID:27240218

  13. Batch-to-batch uniformity of bacterial community succession and flavor formation in the fermentation of Zhenjiang aromatic vinegar.

    Science.gov (United States)

    Wang, Zong-Min; Lu, Zhen-Ming; Yu, Yong-Jian; Li, Guo-Quan; Shi, Jin-Song; Xu, Zheng-Hong

    2015-09-01

    Solid-state fermentation of traditional Chinese vinegar is a mixed-culture refreshment process that proceeds for many centuries without spoilage. Here, we investigated bacterial community succession and flavor formation in three batches of Zhenjiang aromatic vinegar using pyrosequencing and metabolomics approaches. Temporal patterns of bacterial succession in the Pei (solid-state vinegar culture) showed no significant difference (P > 0.05) among three batches of fermentation. In all the batches investigated, the average number of community operational taxonomic units (OTUs) decreased dramatically from 119 ± 11 on day 1 to 48 ± 16 on day 3, and then maintained in the range of 61 ± 9 from day 5 to the end of fermentation. We confirmed that, within a batch of fermentation process, the patterns of bacterial diversity between the starter (took from the last batch of vinegar culture on day 7) and the Pei on day 7 were similar (90%). The relative abundance dynamics of two dominant members, Lactobacillus and Acetobacter, showed high correlation (coefficient as 0.90 and 0.98 respectively) among different batches. Furthermore, statistical analysis revealed dynamics of 16 main flavor metabolites were stable among different batches. The findings validate the batch-to-batch uniformity of bacterial community succession and flavor formation accounts for the quality of Zhenjiang aromatic vinegar. Based on our understanding, this is the first study helps to explain the rationality of age-old artistry from a scientific perspective. PMID:25998816

  14. Comparison of D-gluconic acid production in selected strains of acetic acid bacteria.

    Science.gov (United States)

    Sainz, F; Navarro, D; Mateo, E; Torija, M J; Mas, A

    2016-04-01

    The oxidative metabolism of acetic acid bacteria (AAB) can be exploited for the production of several compounds, including D-gluconic acid. The production of D-gluconic acid in fermented beverages could be useful for the development of new products without glucose. In the present study, we analyzed nineteen strains belonging to eight different species of AAB to select those that could produce D-gluconic acid from D-glucose without consuming D-fructose. We tested their performance in three different media and analyzed the changes in the levels of D-glucose, D-fructose, D-gluconic acid and the derived gluconates. D-Glucose and D-fructose consumption and D-gluconic acid production were heavily dependent on the strain and the media. The most suitable strains for our purpose were Gluconobacter japonicus CECT 8443 and Gluconobacter oxydans Po5. The strawberry isolate Acetobacter malorum (CECT 7749) also produced D-gluconic acid; however, it further oxidized D-gluconic acid to keto-D-gluconates.

  15. Effect of capping agents: Structural, optical and biological properties of ZnO nanoparticles

    Science.gov (United States)

    Javed, Rabia; Usman, Muhammad; Tabassum, Saira; Zia, Muhammad

    2016-11-01

    Different biological activities of capped and uncapped ZnO nanoparticles were investigated, and the effects of potential capping agents on these biological activities were studied. ZnO nanoparticles were synthesized and capped by polyethylene glycol (PEG) and polyvinyl pyrrolidone (PVP) using a simple chemical method of co-precipitation. Characterization by X-ray diffraction (XRD), Fourier transform Infrared spectroscopy (FTIR) and UV-vis spectroscopy confirmed the crystallinity, size, functional group, and band gap of synthesized nanoparticles. Reduction in size occurred from 34 nm to 26 nm due to surfactant. Results of all biological activities indicated significantly higher values in capped as compared to uncapped nanoparticles. Antibacterial activity against Staphylococcus aureus (ATCC 6538), Bacillus subtilis (ATCC 6633), Escherichia coli (ATCC15224), and Acetobacter was obtained. This activity was more prominent against Gram-positive bacteria, and ZnO-PVP nanoparticles elucidated highest antibacterial activity (zone of inhibition 17 mm) against Gram-positive, Bacillus subtilis species. Antioxidant activities including total flavonoid content, total phenolic content, total antioxidant capacity, total reducing power and %age inhibition of DPPH, and antidiabetic activity against α-amylase enzyme found to be exhibited highest by ZnO-PEG nanoparticles.

  16. Metabolic and microbial community dynamics during the hydrolytic and acidogenic fermentation in a leach-bed process

    Energy Technology Data Exchange (ETDEWEB)

    Straeuber, Heike; Kleinsteuber, Sabine [UFZ - Helmholtz Centre for Environmental Research, Leipzig (Germany). Dept. of Bioenergy; UFZ - Helmholtz Centre for Environmental Research, Leipzig (Germany). Dept. of Environmental Microbiology; Schroeder, Martina [UFZ - Helmholtz Centre for Environmental Research, Leipzig (Germany). Dept. of Bioenergy

    2012-12-15

    Biogas production from lignocellulosic feedstock not competing with food production can contribute to a sustainable bioenergy system. The hydrolysis is the rate-limiting step in the anaerobic digestion of solid substrates such as straw. Hence, a detailed understanding of the metabolic processes during the steps of hydrolysis and acidogenesis is required to improve process control strategies. The fermentation products formed during the acidogenic fermentation of maize silage as a model substrate in a leach-bed process were determined by gas and liquid chromatography. The bacterial community dynamics was monitored by terminal restriction fragment length polymorphism analysis. The community profiles were correlated with the process data using multivariate statistics. The batch process comprised three metabolic phases characterized by different fermentation products. The bacterial community dynamics correlated with the production of the respective metabolites. In phase 1, lactic and acetic acid fermentations dominated. Accordingly, bacteria of the genera Lactobacillus and Acetobacter were detected. In phase 2, the metabolic pathways shifted to butyric acid fermentation, accompanied by the production of hydrogen and carbon dioxide and a dominance of the genus Clostridium. In phase 3, phylotypes affiliated with Ruminococcaceae and Lachnospiraceae prevailed, accompanied by the formation of caproic and acetic acids, and a high gas production rate. A clostridial butyric type of fermentation was predominant in the acidogenic fermentation of maize silage, whereas propionic-type fermentation was marginal. As the metabolite composition resulting from acidogenesis affects the subsequent methanogenic performance, process control should focus on hydrolysis/acidogenesis when solid substrates are digested. (orig.)

  17. Development of self-assembled bacterial cellulose-starch nanocomposites

    International Nuclear Information System (INIS)

    A bioinspired bottom-up process was developed to produce self-assembled nanocomposites of cellulose synthesized by Acetobacter bacteria and native starch. This process takes advantage of the way some bacteria extrude cellulose nanofibres and of the transport process that occurs during the gelatinization of starch. Potato and corn starch were added into the culture medium and partially gelatinized in order to allow the cellulose nanofibrils to grow in the presence of a starch phase. The bacterial cellulose (BC)-starch gels were hot pressed into sheets that had a BC volume fraction higher than 90%. During this step starch was forced to further penetrate the BC network. The self-assembled BC-starch nanocomposites showed a coherent morphology that was assessed by Atomic Force Microscopy (AFM) and Environmental Scanning Electron Microscopy (ESEM). The nanocomposites structure was studied using X-ray diffraction and ATR-FTIR spectroscopy. The degree of crystallinity of the final nanocomposites was used to estimate the volume fraction of BC. The aim of this paper is to explore a new methodology that could be used to produce nanomaterials by introducing a different phase into a cellulose nanofibre network during its assembly.

  18. Detailed analysis of the microbial population in Malaysian spontaneous cocoa pulp fermentations reveals a core and variable microbiota.

    Directory of Open Access Journals (Sweden)

    Esther Meersman

    Full Text Available The fermentation of cocoa pulp is one of the few remaining large-scale spontaneous microbial processes in today's food industry. The microbiota involved in cocoa pulp fermentations is complex and variable, which leads to inconsistent production efficiency and cocoa quality. Despite intensive research in the field, a detailed and comprehensive analysis of the microbiota is still lacking, especially for the expanding Asian production region. Here, we report a large-scale, comprehensive analysis of four spontaneous Malaysian cocoa pulp fermentations across two time points in the harvest season and two fermentation methods. Our results show that the cocoa microbiota consists of a "core" and a "variable" part. The bacterial populations show a remarkable consistency, with only two dominant species, Lactobacillus fermentum and Acetobacter pasteurianus. The fungal diversity is much larger, with four dominant species occurring in all fermentations ("core" yeasts, and a large number of yeasts that only occur in lower numbers and specific fermentations ("variable" yeasts. Despite this diversity, a clear pattern emerges, with early dominance of apiculate yeasts and late dominance of Saccharomyces cerevisiae. Our results provide new insights into the microbial diversity in Malaysian cocoa pulp fermentations and pave the way for the selection of starter cultures to increase efficiency and consistency.

  19. 镇江香醋醋醅抑菌活性及机理的初步分析%Antibacterial activity of fermentation culture of Zhenjiang aromatic vinegar

    Institute of Scientific and Technical Information of China (English)

    吉晋波; 陆震鸣; 龚劲松; 余永建; 李国权; 陆茂林; 史劲松; 许正宏

    2016-01-01

    [目的]评价镇江香醋醋酸发酵过程中醋醅及其主要酿醋功能微生物的抑菌活性.[方法]采用琼脂扩散法评价醋醅和功能微生物的抑菌效果,并考察加热、蛋白酶解、透析等不同处理对发酵液抑菌活性的影响.[结果]醋醅水提取液及4种酿醋功能微生物(Acetobacter pasteurianus、A.pomorum、Lactobacillus helveticus、L.plantarum)的发酵上清液对4种指示菌具有明显的生长抑制效果.发酵上清液中的抑菌活性物质具有一定耐热性和蛋白酶敏感性,分子量小于8kD.[结论]镇江香醋醋醅及其所含醋酸杆菌和乳酸杆菌对环境微生物具有生长抑制活性,且抑菌活性物质的种类具有多样性.

  20. Application of Bacteria Cellulose in Food Industry%细菌纤维素在食品工业中的应用

    Institute of Scientific and Technical Information of China (English)

    马霞; 王瑞明; 贾士儒; 关凤梅

    2002-01-01

    @@ 细菌纤维素(Bacterical cellulose,BC)是当今国内外生物材料研究的热点之一.一般认为合成纤维素是植物特有的功能,但是,有少数微生物也能合成纤维素.现已知道,在各种不同条件下能合成纤维素的微生物有醋酸菌属(Acetobacter)、土壤杆菌属(Agrobacterium)、假单胞杆菌属(Pseudomonas)、无色杆菌属(Achrombacter)、产碱杆菌属(Alcaligenes)、气杆菌属(Aerobacter)、固氮菌属(Azotobacter)、根瘤菌属(Rhizabium)和八叠球菌属(Sarcina)等的某些种,它们合成的纤维素统称为细菌纤维素.其中真正能够批量地工业化生产细菌纤维素且合成能力最强的是醋酸菌属(Acetobacter)中的木醋杆菌(Acetobacterxylnium).

  1. 耐高温高醇醋酸菌的筛选及其发酵工艺的初步优化%Screening and fermentation optimization of a thermoresistant and alcohol-tolerant acetic acid bacterium

    Institute of Scientific and Technical Information of China (English)

    孙文瑛; 陈雄; 王志; 王永泽; 雷锦成; 姚娟

    2011-01-01

    Twelve acetic acid bacteria were isolated from some rotten fruits, one of which was selected for its comprehensive performance on alcohol tolerance, temperature tolerance and acetic acid production was highest, and identified as Acetobacter according to physiological-biochemical characteristics and 16S rDNA analysis. The optimal fermentation medium for the strain was op timized by orthogonal test as follows: glucose 2%,yeast extract 2%, MgSO4·7H2O 0.02%, KH2PO4 0.1%, ethanol 7%vol. and the ultimate acetic acid production can reach to 48.6g/L.%分别从各种腐烂水果中分离出12株产醋酸菌,比较其对乙醇和温度的耐受性以及发酵产醋酸的量,选择综合性能相对最高的一株,利用生理生化实验和16S rDNA同源序列分析,初步认定其为Acetobacter属.正交试验优化该菌最佳发酵培养基为:葡萄糖2%,酵母粉2%,MgSO4·7H2O.02%,KH2PO40.1%,乙醇7%vol,醋酸产量为48.6g/L.

  2. Preliminary Study on Biosynthesis of Bacterial Nanocellulose Tubes in a Novel Double-Silicone-Tube Bioreactor for Potential Vascular Prosthesis

    Directory of Open Access Journals (Sweden)

    Feng Hong

    2015-01-01

    Full Text Available Bacterial nanocellulose (BNC has demonstrated a tempting prospect for applications in substitute of small blood vessels. However, present technology is inefficient in production and BNC tubes have a layered structure that may bring danger after implanting. Double oxygen-permeable silicone tubes in different diameters were therefore used as a tube-shape mold and also as oxygenated supports to construct a novel bioreactor for production of the tubular BNC materials. Double cannula technology was used to produce tubular BNC via cultivations with Acetobacter xylinum, and Kombucha, a symbiosis of acetic acid bacteria and yeasts. The results indicated that Kombucha gave higher yield and productivity of BNC than A. xylinum. Bacterial nanocellulose was simultaneously synthesized both on the inner surface of the outer silicone tube and on the outer surface of the inner silicone tube. Finally, the nano BNC fibrils from two directions formed a BNC tube with good structural integrity. Scanning electron microscopy inspection showed that the tubular BNC had a multilayer structure in the beginning but finally it disappeared and an intact BNC tube formed. The mechanical properties of BNC tubes were comparable with the reported value in literatures, demonstrating a great potential in vascular implants or in functional substitutes in biomedicine.

  3. PERBAIKAN PROSES FERMENTASI BIJI KAKAO KERING DENGAN PENAMBAHAN TETES TEBU, KHAMIR, DAN BAKTERI ASAM ASETAT

    Directory of Open Access Journals (Sweden)

    Donny Widianto, Ajeng Dara Pramita, dan Sri Wedhastri

    2013-12-01

    Full Text Available Most of cocoa beans produced by smallholder farmers were non fermented which can be improved by modifiedfermentation processing. This study was aimed to inverstigate the influence of molasses, yeast Saccharomycescerevisiae, and Acetobacter aceti addition on dried cocoa beans fermentation process.Fresh cocoa beans were dried in a glasshouse and its reducing sugar was analyzed before and after drying. Asmall plastic bucket (20 cm diameter and 30 cm height with aeration holes was used as fermentation vessel. Driedcocoa beans were soaked in distilled water for 4 hours, inoculated with yeast and acetic acid bacteria cultures, andmolasses were added at two different concentration, i.e, 1 and 1.5 times of reducing sugar lost during drying.Reducing sugar, ethanol, titrated acid, population of yeast, and acetic acid bacteria were monitored duringfermentation. After fermentation the beans were sun dried and its pH and degree of fermentation were determinedto assess the bean quality.The results showed that the addition of molasses mostly at the level of 1.5, S. cerevisiae, and A. aceti increasereducing sugar, ethanol, titrated acid, yeast and acetic acid bacteria of fermentation liquid (pulp. The highestpercentage of fermented beans (68.4 % was achieved by addition of S. cerevisiae, A. aceti, and molasses atthe level 1.5. It is likely that the addition of S. cerevisiae, A. aceti, and molasses could improve fermentationprocessing of dried cocoa bean.

  4. Permeabilidad hidráulica e hinchamiento de membranas de celulosa bacteriana

    Directory of Open Access Journals (Sweden)

    L.A. Caicedo

    2006-01-01

    Full Text Available El grado de hinchamiento y la permeabilidad hidráulica fueron evaluados en membranas de celulosa bacteriana obtenida por cultivo estático de Acetobacter sp. por tres y nueve días, en medio con glucosa y extracto de levadura. Las pruebas de hinchamiento fueron realizadas en disoluciones etanólicas de 0, 10, 50 y 95 % (v/v de etanol, por 24 h a (18 ± 1 °C . El grado de hinchamiento definido como la relación entre la diferencia de peso final e inicial y peso inicial de la membrana, mostró que estas pueden retener 690 veces su peso en agua, en tanto que en disoluciones del 95 % solo se retiene 10 veces su peso seco. Membranas prehinchadas en agua retienen cerca de 4 veces más con respecto a las no prehinchadas. El flujo de permeado es proporcional a la presión aplicada y la permeabilidad hidráulica para membranas de nueve días fue de 0,227 3 mL/kPa199 · cm2 · min, cerca del 50 % de la permeabilidad obtenida en membranas de 3 d . Con disoluciones de etanol las membranas presentaron permeabilidades menores en relación con las obtenidas con agua.

  5. Mechanical and thermal properties of bacterial-cellulose-fibre-reinforced Mater-Bi® bionanocomposite

    Directory of Open Access Journals (Sweden)

    Hamonangan Nainggolan

    2013-05-01

    Full Text Available The effects of the addition of fibres of bacterial cellulose (FBC to commercial starch of Mater-Bi® have been investigated. FBC produced by cultivating Acetobacter xylinum for 21 days in glucose-based medium were purified by sodium hydroxide 2.5 wt % and sodium hypochlorite 2.5 wt % overnight, consecutively. To obtain water-free BC nanofibres, the pellicles were freeze dried at a pressure of 130 mbar at a cooling rate of 10 °C min−1. Both Mater-Bi and FBC were blended by using a mini twin-screw extruder at 160 °C for 10 min at a rotor speed of 50 rpm. Tensile tests were performed according to ASTM D638 to measure the Young’s modulus, tensile strength and elongation at break. A field emission scanning electron microscope was used to observe the morphology at an accelerating voltage of 10 kV. The crystallinity (Tc and melting temperature (Tm were measured by DSC. Results showed a significant improvement in mechanical and thermal properties in accordance with the addition of FBC into Mater-Bi. FBC is easily incorporated in Mater-Bi matrix and produces homogeneous Mater-Bi/FBC composite. The crystallinity of the Mater-Bi/FBC composites decrease in relation to the increase in the volume fraction of FBC.

  6. 细菌纤维素的合成及表征%Synthesis and Characterization of Bacterial Cellulose Membrane

    Institute of Scientific and Technical Information of China (English)

    张名楠; 刘海芳; 韩亚丽; 冯玉红

    2014-01-01

    以海南椰子水为主要培养体系,实验室自行筛选的木醋杆菌(Acetobacter xylinum)为菌种,采用静态培养方法制备了细菌纤维素(BC).对该BC和商业BC的结构和性能进行了测试对比,观察BC的微结构特点.结果表明:制备的BC和商业BC在结构和一些性能方面是相似的,都是无色透明膜,呈三维网状结构和孔洞结构,具有良好的纳米纤维网络特征,具有良好的吸湿性和极佳的持水能力,该实验制备的BC生产成本低,可根据需要大量制备,在生物医学领域具有良好的、广泛的应用前景.

  7. ISOLATION AND IDENTIFICATION OF BACTERIA FROM DISEASE LEAVES OF PINUS TABULAEFORMIS CARR%感病油松针叶中细菌的分离与鉴定

    Institute of Scientific and Technical Information of China (English)

    李志刚; 赵国芬; 朗建华; 郑婷

    2010-01-01

    该试验以呼市清水河地区感病油松针叶为材料,分离获得8株菌株.通过16SrDNA序列及同源性比较,结合菌落特征和细菌形态,对菌株进行鉴定,8株菌株分别为绿浅气球菌Aerococcus viridans,解淀粉芽胞杆菌Aerococcus viridans,沙雷菌属Serratia,枯草芽孢杆菌Bacillus subtilis,醋杆菌属Acetobacter,变形斑沙雷菌Serratia proteamaculans,不动杆菌属Acinetobacter和蜡状芽孢杆菌bacillus cereua,该8株菌株均不是引起油松疑似病害的微生物.该研究为清水河油松病情诊断和分析提供理论和技术支撑.

  8. Impact of the resident microbiota on the nutritional phenotype of Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Emma V Ridley

    Full Text Available BACKGROUND: Animals are chronically infected by benign and beneficial microorganisms that generally promote animal health through their effects on the nutrition, immune function and other physiological systems of the host. Insight into the host-microbial interactions can be obtained by comparing the traits of animals experimentally deprived of their microbiota and untreated animals. Drosophila melanogaster is an experimentally tractable system to study host-microbial interactions. METHODOLOGY/PRINCIPAL FINDINGS: The nutritional significance of the microbiota was investigated in D. melanogaster bearing unmanipulated microbiota, demonstrated by 454 sequencing of 16S rRNA amplicons to be dominated by the α-proteobacterium Acetobacter, and experimentally deprived of the microbiota by egg dechorionation (conventional and axenic flies, respectively. In axenic flies, larval development rate was depressed with no effect on adult size relative to conventional flies, indicating that the microbiota promotes larval growth rates. Female fecundity did not differ significantly between conventional and axenic flies, but axenic flies had significantly reduced metabolic rate and altered carbohydrate allocation, including elevated glucose levels. CONCLUSIONS/SIGNIFICANCE: We have shown that elimination of the resident microbiota extends larval development and perturbs energy homeostasis and carbohydrate allocation patterns of of D. melanogaster. Our results indicate that the resident microbiota promotes host nutrition and interacts with the regulation of host metabolism.

  9. Synthesis of {sup 14}C-labelled hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), 2,4,6-trinitrotoluene (TNT), nitrocellulose (NC) and glycidyl azide polymer (GAP) for use in assessing the biodegradation potential of these energetic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Ampleman, G.; Thiboutot, S.; Lavigne, J.; Marois, A. [Defence Research Establishment Valcartier, Courcelette, PQ (Canada); Hawari, J.; Jones, A.M.; Rho, D. [National Research Council of Canada, Ottawa, ON (Canada)

    1995-06-01

    Within the framework of an R and D project on bioremediation of soils contaminated with energetic compounds, the biodegradation of energetic products such as hexogen (RDX), trinitrotoluene (TNT), nitrocellulose (NC) and glycidyl azide polymer (GAP) is under study. Microcosm assays must be performed with radioactive carbon-14 labelled products in order to follow the biodegradation process. {sup 14}C-RDX was prepared by nitration of hexamethylenetetramine (HMTA) according to the Hale process. {sup 14}C-ring and methyl labelled TNTs synthesized according to the Dorey and Carper procedure. {sup 14}C-cellulose was synthesized from {sup 14}C-glucose by Acetobacter xylinum. Nitration of the {sup 14}C-cellulose yielded {sup 14}C-nitrocellulose. {sup 14}C-glycidyl azide polymer was obtained by polymerization and azidation of {sup 14}C-epichlorohydrin (ECH) which was synthesized from {sup 14}C-glycerol. Hydrochlorination of {sup 14}C-glycerol and epoxidation of the resulting {sup 14}C-1,3-dichloro 2-propanol yielded {sup 14}C-ECH. The syntheses of these {sup 14}C-labelled explosives are described in this paper. (Author).

  10. The bacterial communities of Drosophila suzukii collected from undamaged cherries

    Directory of Open Access Journals (Sweden)

    James Angus Chandler

    2014-07-01

    Full Text Available Drosophila suzukii is an introduced pest insect that feeds on undamaged, attached fruit. This diet is distinct from the fallen, discomposing fruits utilized by most other species of Drosophila. Since the bacterial microbiota of Drosophila, and of many other animals, is affected by diet, we hypothesized that the bacteria associated with D. suzukii are distinct from that of other Drosophila. Using 16S rDNA PCR and Illumina sequencing, we characterized the bacterial communities of larval and adult D. suzukii collected from undamaged, attached cherries in California, USA. We find that the bacterial communities associated with these samples of D. suzukii contain a high frequency of Tatumella. Gluconobacter and Acetobacter, two taxa with known associations with Drosophila, were also found, although at lower frequency than Tatumella in four of the five samples examined. Sampling D. suzukii from different locations and/or while feeding on different fruits is needed to determine the generality of the results determined by these samples. Nevertheless this is, to our knowledge, the first study characterizing the bacterial communities of this ecologically unique and economically important species of Drosophila.

  11. Bacterial Cellulose From Rice Waste Water With Addition Chitosan, Glycerol, And Silver Nanoparticle

    Directory of Open Access Journals (Sweden)

    Eli Rohaeti

    2016-05-01

    Full Text Available This study aimed to prepare silver nanoparticles chemically, deposite silver nanoparticles on bacterial cellulose-chitosan-glycerol composite based rice waste water, as well as test the antibacterial activity of bacterial cellulose and its composite. Preparation of silver nanoparticles was conducted by chemical reduction of silver nitrate solution, as well as trisodium citrate as the reductor. Bacterial cellulose from rice waste water is fermented by the bacteria Acetobacter xylinum for 7 days. The dried bacterial cellulose was composited with chitosan and glycerol by immersion method on 2% of chitosan solution and 0.5% of glycerol solution. UV-Vis spectroscopy is used to determine the formation of silvernanoparticles and Particle Size Analyzer to test the size and particle size distribution. Characterization was conducted to bacterial cellulose and its composite included functional groups by FTIR, the mechanical properties by Tensile Tester, crystallinity by XRD, surface photograph by SEM, and antibacterial test against S. aureus and E. coli by the shake flask turbidimetry method. Silver nanoparticle characterization indicated that silver nanoparticles are formed at a wavelength of 421.80 nm, yellow, diameter particle size of 61.8 nm. SEM images showed that the surface of bacterial cellulose had deposited silver nanoparticles and antibacterial test showed an inhibitory effect of bacterial cellulose, bacterial cellulose-chitosan composite, and bacterial cellulose-chitosan-glycerol composite which are deposited silver nanoparticles against the growth of S. aureus and E. coli bacteria.

  12. Transcriptional Modulation of Squalene Synthase Genes in Barley Treated with PGPR

    Directory of Open Access Journals (Sweden)

    Anam eYousaf

    2015-09-01

    Full Text Available Phytosterol contents and food quality of plant produce is directly associated with transcription of gene Squalene Synthase (SS. In current study, barley plants were treated with different rhizobacterial strains under semi controlled (27±3°C greenhouse conditions in order to modulate expression of SS gene. Plant samples were analysed through semi-quantitative PCR to evaluate effect of rhizobacterial application on transcriptional status of squalene synthase. Results revealed that among four SS genes (i.e. SSA, SS1, SS2 and SS3, the most expressive gene was SSA; while, SS2 was screened out as the second best induced gene due to Acetobacter aceti. The most efficient bacterial strain which recorded maximum gene expression was A. aceti AC8. Moreover, AC7 was reported as the least efficient bacterial species for inducing SS gene expression. AC8 enhanced the share of SSA and SS2 up to 43% and 31%, respectively. The study also described ribosomal sequence of the most efficient bacterial strain AC8, which was used to determine its phylogenetic relationships with other microbial strains. The study would be helpful to improve quality of plant produce by modulating transcription of SS genes.

  13. Development of self-assembled bacterial cellulose-starch nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Grande, Cristian J. [Faculty of Mechanical Engineering, Catholic University of Peru (PUCP), Lima 32 (Peru); Torres, Fernando G., E-mail: fgtorres@pucp.edu.pe [Faculty of Mechanical Engineering, Catholic University of Peru (PUCP), Lima 32 (Peru); Gomez, Clara M., E-mail: Clara.Gomez@uv.es [Departament de Quimica Fisica and Institut de Ciencia dels Materials, Dr Moliner 50, Universitat de Valencia, E-46100 Burjassot, Valencia (Spain); Troncoso, Omar P. [Faculty of Mechanical Engineering, Catholic University of Peru (PUCP), Lima 32 (Peru); Canet-Ferrer, Josep; Martinez-Pastor, Juan [Unit of Optoelectronic Materials and Devices of the University of Valencia, P.O. Box 22085, 46071 Valencia (Spain)

    2009-05-05

    A bioinspired bottom-up process was developed to produce self-assembled nanocomposites of cellulose synthesized by Acetobacter bacteria and native starch. This process takes advantage of the way some bacteria extrude cellulose nanofibres and of the transport process that occurs during the gelatinization of starch. Potato and corn starch were added into the culture medium and partially gelatinized in order to allow the cellulose nanofibrils to grow in the presence of a starch phase. The bacterial cellulose (BC)-starch gels were hot pressed into sheets that had a BC volume fraction higher than 90%. During this step starch was forced to further penetrate the BC network. The self-assembled BC-starch nanocomposites showed a coherent morphology that was assessed by Atomic Force Microscopy (AFM) and Environmental Scanning Electron Microscopy (ESEM). The nanocomposites structure was studied using X-ray diffraction and ATR-FTIR spectroscopy. The degree of crystallinity of the final nanocomposites was used to estimate the volume fraction of BC. The aim of this paper is to explore a new methodology that could be used to produce nanomaterials by introducing a different phase into a cellulose nanofibre network during its assembly.

  14. Isolation and enrichment culturing of a soil bacterial-feeding nematode%土壤食细菌线虫的分离和富集培养方法

    Institute of Scientific and Technical Information of China (English)

    李辉信; 陈小云; 胡锋

    2002-01-01

    从小麦根际土中分离得到一种能取食B1和B2两种细菌的土壤食细菌线虫,并在马铃薯蔗糖培养基上富化培养成功.经鉴定该线虫为原小杆线虫属(Protorhabditis sp.),B1为假单胞菌属(Pseudomonas sp.),B2为醋杆菌属(Acetobacter sp.).用牛肉膏蛋白胨细菌培养基培养B1和B2两种细菌时,细菌无多糖产生,线虫不能取食细菌而生长繁殖;当用马铃薯蔗糖真菌培养基培养B1和B2两种细菌时,细菌分泌丰富的多糖,线虫生长繁殖较好.多糖是线虫生长繁殖的重要外部环境.

  15. 红枣红茶菌发酵饮料的研制%Study on a tea fungus-fermented beverage made from jujube juice

    Institute of Scientific and Technical Information of China (English)

    陈胜慧子; 侯旭杰

    2012-01-01

    以新疆干骏枣为原料,采用红茶菌(酿酒酵母菌Saccharomyces cerevisiae Hansen、纹膜醋酸杆菌Acetobacter aceti、植物乳酸杆菌Lactobacilha plantarum)为菌种,经发酵研制红枣红茶菌发酵饮料.研究了红枣汁添加量、红茶菌接种比例、发酵时间、温度和供氧量等因素对红枣红茶菌发酵饮料发酵工艺的影响,确定其最佳工艺为:红茶菌接种量5%(乳酸菌∶醋酸菌∶酵母菌=2∶2∶1)、枣水比1∶3.5、发酵时间4d、温度30℃,供氧方式为10层左右的纱布封口震荡培养.该发酵饮料酸甜爽口,枣香醇厚.

  16. PEMANFAATAN MEMBRAN NATA DE COCO SEBAGAI MEDIA FILTRASI UNTUK REKOVERIMINYAK JELANTAH

    Directory of Open Access Journals (Sweden)

    Senny Widyaningsih

    2013-05-01

    Full Text Available Peningkatan kualitas minyak jelantah telah dilakukan dengan metode filtrasi menggunakan membran selulosa bakterial yang terbuat dari nata de coco. Pembuatan membran nata de coco dilakukan dengan cara memurnikan nata de coco hasil proses fermentasi bakteri Acetobacter xylinum. Karakterisasi membran meliputi berat jenis, nilai fluks, dan koefisien rejeksi. Proses filtrasi minyak jelantah menggunakan tekanan sebesar 4 kgf/cm2 dengan metode dead-end. Hasil penelitian menunjukkan bahwa karakterisasi membran nata de coco memiliki berat jenis sebesar 0,6314 g/cm3, nilai fluks air sebesar 104,021 L/m2.jam, fluks minyak sebesar 1,004 L/m2.jam dan fluks Dekstran T-500 sebesar 52,208 L/m2.jam. Nilai rejeksi membran sebesar 15,11%. Peningkatan kualitas minyak jelantah dibanding sebelum rekoveri dapat dilihat dari penurunan angka asam sebesar 54,95%, kadar air sebesar 93,22%, serta peningkatan angka penyabunan sebesar 29,09% dan angka iod sebesar 8,14%.

  17. EFEKTIVITAS NIRA AREN SEBAGAI BAHAN PENGEMBANG ADONAN ROTI

    Directory of Open Access Journals (Sweden)

    Mody Lempang

    2013-12-01

    Full Text Available Fermentation is a natural process that happen in fresh-sweet sap of aren trees (Arenga pinnata Merr., because many kinds of microorganism stay and life in this substance e.g. bakteria (Acetobacter acetic and yeast (Saccharomyces tuac. Species of yeast from genus of Saccharomyses, e.g. Saccharomyses serivisae is wellknown as microorganism that can ferment sugar (glucose into alchohol and CO2. This natural process as well happen in aren sap, so that this substance potencially using as a swollen agent of bread or cake dough. This research objective is to recognize the effectiveness of aren sap as a swollen agent of bread dough. Fermentation duration of bread dough was one hour by using swollen agent of fresh, 10 hours old and 20 hours old of aren sap. Daily yield of sap tapped from aren trees in Maros district, South Sulawesi province was 7 litre (4-5 litre collected in the morning and 2-3 litre colected in the afternoon. Aren sap containt some of nutritions e.g. carbohydrate, protein, fat, vitamin C and mineral. Sweet taste of aren sap caused by it’s charbohydrate content of 11.18%. The effectiveness of aren sap as a swollen agent of bread dough is lower than instant (commercial yeast. The older of aren sap the lower of it’s effectiveness as a swollen agent of dough and kuality of bread yield.    Keywords : Sap, Arenga pinnata, swollen agent, bread dough

  18. Isolation and Characterization of Diazotrophic Rhizobacteria of Oil Palm Roots

    Directory of Open Access Journals (Sweden)

    Azlin, C. O.

    2005-01-01

    Full Text Available Beneficial rhizobacteria were isolated from two different compartments of oil palm roots; the rhizosphere or rhizoplane and the inner root tissues. The root samples were collected from oil palm plantation at Felda Lepar 9, Temerloh Pahang (Block 17, Square 6 (soil pH 4.30; 10:25 0.01M CaCl2. Identification of the isolates was conducted by classical biochemical and physiological tests. Acetylene Reduction Assay (ARA test was also conducted to quantify the ability of the isolates to fix atmospheric N2. Twenty-nine strains of rhizobacteria were isolated from root samples and were maintained aerobically on N-free solid media. Seven of the isolates were identified as Gram negative while the rest were Gram positive. The isolates were successfully identified as Paenibacillus durus (formerly P. azotofixans, Paenibacillus polymyxa, Azospirillum lipoferum, Herbaspirillum seropedicae and Acetobacter diazotrophicus. The N2 fixation capacities of the isolates ranged from 7.0 x 10-12 to 1.0 x 10-8 mol C2H4/cfu/hour.

  19. 麦麸醋天然药曲中醋酸菌的分离及初步鉴定%Isolation and Primary Identification of Acetic Acid Bacteria from Natural Yaoqu of Bran Vinegar

    Institute of Scientific and Technical Information of China (English)

    叶阳; 王洋; 左勇; 郑丽

    2014-01-01

    Isolate and screen 4 acid-producing strains from natural Yaoqu of bran vinegar,then study these strains'capacity of acid production,alcohol-resistant and salt tolerance.The results show that the highest acid producing amount of the strains is up to 24.3 g/L,the highest resistance to alcohol is 7% and the highest resistance to salt is 0.9%.According to the morphology,physiological and biochemical characteristics of these strains,strain A2 is primarily identified as A.aceti and strains A, A1 ,A3 are primarily identified as A.pasteurianus.%从麦麸醋天然药曲中分离筛选出四株产酸菌株,并对其进行产酸性能、耐酒精度及耐盐性能进行研究。实验结果表明:最高产酸量可达24.3 g/L,最高耐酒精度达到7%,最高耐盐浓度达到0.9%。通过对菌株形态观察及生理生化鉴定,初步判定 A2为醋化醋杆菌(Acetobacter aceti),A,A1,A3为巴氏醋杆菌(A.pasteurianus)。

  20. Biological Treatment of the Wastewater from Steroid Drug Production%甾体药物生产废水的生物处理

    Institute of Scientific and Technical Information of China (English)

    李尔炀; 王大慧

    2004-01-01

    以甾体药物生产废水中的主要污染物为底物,从自然界筛选了高效降解菌株6株,经鉴定,他们分别为假单胞菌(Pseudomonas sp.)、醋酸杆菌(Acetobacter sp.)和不动杆菌(Acinetobacter sp.).采用好氧工艺,以筛选出的高效菌株为降解菌,用正交法研究了高效菌降解废水的工艺条件,最佳工艺条件为:菌体质量浓度10 g/L(湿),pH 7.0,摇床转速110 r/min.影响CODcr去除率的因子顺序为:菌体质量浓度>pH>摇床转速.在最佳工艺条件下,高效菌的CODcr去除率达到94%,出水可达到国家二级污水排放标准.

  1. 惰性吸附载体固态发酵细菌纤维素的研究%Production of Bacterial Cellulose Under Solid State Fermentation on Polyurethane Foam

    Institute of Scientific and Technical Information of China (English)

    翁媛媛; 陈洪章

    2010-01-01

    惰性载体吸附固态发酵是一种新型的固态发酵方式.以聚氨酯塑料泡沫为吸附载体,对木醋杆菌(Acetobacter xylinum)CGMCC No.1.1812吸附载体固态发酵过程中影响纤维素产量的因素及发酵过程进行了初步研究.结果表明,在固液比为1:16,载体堆料高度为3 cm,初始葡萄糖质量浓度为20 g/L时,72 h发酵,细菌纤维素产量可达到4.86 g/L,整个发酵周期的容积生产率可达到1.62 g/(L·d).与常规液态静置发酵相比,发酵产量同期提高了5.65倍,一个发酵周期的容积生产率提高了3.16倍.

  2. Characterization of the bacterial cellulose dissolved on dimethylacetamide/lithium chloride

    Energy Technology Data Exchange (ETDEWEB)

    Lima, Glaucia de Marco [Universidade do Vale do Itajai (PMCF/UNIVALI), Itajai, SC (Brazil). Programa de Mestrado em Ciencias Farmaceuticas; Sierakowski, Maria Rita; Faria-Tischer, Paula C.S.; Tischer, Cesar A., E-mail: cesar.tischer@pq.cnpq.b [Universidade Federal do Parana (BIOPOL/UFPR), Curitiba, PR (Brazil). Lab. de Biopolimeros

    2009-07-01

    The main barrier to the use of cellulose is his insolubility on water or organic solvents, but derivates can be obtained with the use of ionic solvents. Bacterial cellulose, is mainly produced by the bacterium Acetobacter xylinum, and is identical to the plant, but free of lignin and hemi cellulose, and with several unique physical-chemical properties. Cellulose produced in a 4 % glucose medium with static condition was dissoluted on heated DMAc/LiCl (120 '0 C, 150 '0 C or 170 '0 C). The product of dissolved cellulose was observed with 13 C-NMR and the effect on crystalline state was seen with x-ray crystallography. The crystalline structure was lost in the dissolution, becoming an amorphous structure, as well as Avicel. The process of dissolution of the bacterial cellulose is basics for the analysis of these water insoluble polymer, facilitating the analysis of these composites, by 13 C-NMR spectroscopy, size exclusion chromatography and light scattering techniques. (author)

  3. PENURUNAN KONSENTRASI ZAT WARNA DALAM LIMBAH BATIK MENGGUNAKAN MEMBRAN DARI Sargassum sp.

    Directory of Open Access Journals (Sweden)

    Senny Widyaningsih

    2014-11-01

    Full Text Available Pencemaran perairan merupakan masalah yang selalu dihadapi oleh industri batik, terutama akibat pemakaian pewarna tekstil. Teknologi membran merupakan salah satu metode yang dapat digunakan untuk pengolahan limbah cair. Membran merupakan lapisan tipis yang berfungsi sebagai filtrasi. Salah satu bahan baku pembuat membran adalah selulosa bakteri. Selulosa bakteri adalah selulosa hasil fermentasi bakteri Acetobacter xylinum yang mengubah glukosa menjadi selulosa.. Penelitian ini memanfaatkan rumput laut jenis alga cokelat (Sargassum sp. yang dianggap sebagai sampah di pantai sebagai sumber glukosa. Fermentasi alga cokelat dilakukan dengan 3 variasi waktu fermentasi yaitu 7, 10, dan 13 hari. Selulosa bakteri optimum yang dihasilkan adalah selulosa bakteri dengan waktu fermentasi 10 hari, berwarna putih dengan ketebalan 1 cm. Membran Sargassum sp. dihasilkan dengan cara pengepresan selulosa bakteri. Hasilnya membrane Sargassum sp. memiliki ketebalan sebesar 1,8 mm, fluks sebesar 3,386 L. m-2.jam-1dan rejeksi sebesar 39,34%. Membran Sargassum sp. digunakan untuk menurunkan konsentrasi zat warna batik dengan cara filtrasi. Zat warna tersebut adalah rodamin B, metilen biru, dan metal jingga. Penurunan konsentrasi yang diperoleh untuk masing-masing zat warna rodamin B, metilen biru dan metil jingga berturut-turut adalah 80,04; 77,83 dan 75,84%. Penelitian ini menunjukkan bahwa membran Sargasuum sp. dapat digunakan dalam pengolahan limbah cair industri batik.

  4. In-vitro Degradation Behaviour of Irradiated Bacterial Cellulose Membrane

    Directory of Open Access Journals (Sweden)

    D. Darwis

    2012-08-01

    Full Text Available Bacterial cellulose membrane synthesized by Acetobacter xylinum in coconut water medium has potential application for Guided bone Regeneration. However, this membrane may not meet some application requirements due to its low biodegradation properties. In this paper, incorporation of gamma irradiation into the membrane is a developed strategy to increase its biodegradability properties. The in–vitro degradation study in synthetic body fluid (SBF of the irradiated membrane has been analyzed during periods of 6 months by means of weight loss, mechanical properties and scanning electron microscopy observation compared to that the un-irradiated one. The result showed that weight loss of irradiated membrane with 25 kGy and 50 kGy and immersed in SBF solution for 6 months reached 18% and 25% respectively. While un-irradiated membrane did not give significant weight loss. Tensile strength of membranes decreases with increasing of irradiation dose and further decreases in tensile strength is observed when irradiated membrane was followed by immersion in SBF solution. Microscope electron image of cellulose membranes shows that un-irradiated bacterial cellulose membrane consists of dense ultrafine fibril network structures, while irradiation result in cleavage of fibrils network of cellulose. The fibrils network become loosely after irradiated membrane immersed in SBF solution due to released of small molecular weight carbohydrates formed during by irradiation from the structure

  5. Application of Bacterial Cellulose to Low-Fat Sausage%细菌纤维素在低脂肉肠中的应用

    Institute of Scientific and Technical Information of China (English)

    薛璐; 杨谦; 李晓东

    2005-01-01

    本研究使用醋杆菌Acetobacter xylinumC5,利用大豆乳清发酵得到的细菌纤维素作为脂肪模拟物和乳化剂,应用到肉肠的加工当中.实验证明,细菌纤维素可以部分,甚至完全替代肉肠中的肥肉.含有大豆乳清细菌纤维素的肉肠,在外观、风味、口感等方面与普通肉肠没有明显差别.将卡拉胶与细菌纤维素配合使用,可以赋予肉肠更良好的口感和组织状态.添加细菌纤维素的肉肠的热量减少了28%~56%.

  6. Study on fermentation conditions of palm juice vinegar by response surface methodology and development of a kinetic model

    Directory of Open Access Journals (Sweden)

    S. Ghosh

    2012-09-01

    Full Text Available Natural vinegar is one of the fermented products which has some potentiality with respect to a nutraceutical standpoint. The present study is an optimization of the fermentation conditions for palm juice vinegar production from palm juice (Borassus flabellifer wine, this biochemical process being aided by Acetobacter aceti (NCIM 2251. The physical parameters of the fermentation conditions such as temperature, pH, and time were investigated by Response Surface Methodology (RSM with 2³ factorial central composite designs (CCD. The optimum pH, temperature and time were 5.5, 30 °C and 72 hrs for the highest yield of acetic acid (68.12 g / L. The quadratic model equation had a R² value of 0.992. RSM played an important role in elucidating the basic mechanisms in a complex situation, thus providing better process control by maximizing acetic acid production with the respective physical parameters. At the optimized conditions of temperature, pH and time and with the help of mathematical kinetic equations, the Monod specific growth rate ( µ max= 0.021 h-1, maximum Logistic specific growth rate ( µ 'max = 0.027 h-1 and various other kinetic parameters were calculated, which helped in validation of the experimental data. Therefore, the established kinetic models may be applied for the production of natural vinegar by fermentation of low cost palm juice.

  7. TERPENOIDS FROM THE STEM BARK OF JATROPHA PLANTS AND THEIR BIOLOGICAL ACTIVITIES

    Directory of Open Access Journals (Sweden)

    Manggau Marianti

    2011-11-01

    Full Text Available Three terpenoids, including two diterpenes (curcusone B and jatrophone and a triterpene (stigmasterol have beenisolated from the stem bark of Jatropha plants. Curcusone B and stigmasterol were isolated from J. curcas, meanwhilejatrophone and stigmasterol were from J. gossypifolia. The biological activities of these compounds have beenevaluated toward bacteria, fungi and tumour cells. Isolation was carried out in vacuum liqiud cromatography (VLCtechnique with silica gel as an adsorben and some solvents as eluents. The compound structures were determined byspectroscopic methodes i.e. UV-vis, FTIR, NMR (1-D, 2-D and were then compared based on their spectroscopic datawith similiar data from literatures. The biological properties of these compounds were evaluated against four strains ofbacteria (Acetobacter sp., Eschericia coli, Staphylococcus aureus, and Streptococcus sp., 4 strains of fungi (Aspergilusniger, Penicillium sp. (grey, Penicillium sp. (white and Rhizopus sp. and murine leukemia P-388 cells. The resultsshowed that cytotoxic property of curcusone B towards murine leukemia P-388 cells is better than jatrophone andstigmasterol which are IC50 = 0.57 μg/mL (1.93 μM for curcusone B and IC50 > 100 μg/mL for jatrophone andstigmasterol. Meanwhile, activities against bacteria, jatrophone is better than curcusone B and stigmasterol. Jatrophoneis the most active against S. aureus (bacteria with growth inhibition zone 36 mm and A.niger (fungi is 44 mm. Furtherstudy indicated that jatrophone was bacteriostatic against S. aureus.

  8. Unusal pattern of product inhibition: batch acetic acid fermentation

    Energy Technology Data Exchange (ETDEWEB)

    Bar, R.; Gainer, J.L.; Kirwan, D.J.

    1987-04-20

    The limited tolerance of microorganisms to their metabolic products results in inhibited growth and product formation. The relationship between the specific growth rate, micro, and the concentration of an inhibitory product has been described by a number of mathematical models. In most cases, micro was found to be inversely proportional to the product concentration and invariably the rate of substrate utilization followed the same pattern. In this communication, the authors report a rather unusual case in which the formation rate of a product, acetic acid, increased with a decreasing growth rate of the microorganism, Acetobacter aceti. Apparently, a similar behavior was mentioned in a review report with respect to Clostridium thermocellum in a batch culture but was not published in the freely circulating literature. The fermentation of ethanol to acetic acid, C/sub 2/H/sub 5/OH + O/sub 2/ = CH/sub 3/COOH + H/sub 2/O is clearly one of the oldest known fermentations. Because of its association with the commercial production of vinegar it has been a subject of extensive but rather technically oriented studies. Suprisingly, the uncommon uncoupling between the inhibited microbial growth and the product formation appears to have been unnoticed. 13 references.

  9. Production of microbial exopolymers for application as flocculants in waste water treatment

    Energy Technology Data Exchange (ETDEWEB)

    Poerschmann, S.; Paetz, R.; Zirkler, W. (Institut fuer Biotechnologie, Leipzig (Germany))

    1991-01-01

    Organic synthetic polymers such as polyacrylamide derivates, polyethylenimine, Na polyacrylates e.t.c. have received much attention as flocculating substances used in waste water treatment. There is an urgent need for the production of effective flocculants to replace mechanical separation methods or, at least, to optimize them. Biological safety and decomposition are essential pre-requisits for utilizing flocculants produced by microbial processes (e.g. discontinuous and continuous cultivation of bacteria or yeasts). The extracted polymers consisting of proteins, lipids, nucleic acids and polysaccharides are capable of being degraded easily by microbiological reactions because they are natural compounds. The induction phase of excreting cellularic biopolymers is the crucial stage. In the special literature, low pO{sub 2} levels associated with a high concentration of the carbon source, limitation of N, P and trace elements have been recommended for the induction of excreting exopolymers. In order to ensure sufficiant induction, we preferred a special procedure, the main characteristic of it being changed between limitation and excessive supply of components essential for the growth of microorganisms. The quality control of exopolysaccharides for flocculation was determined by turbidimetric methods and sedimentation tests with caoline as a standard substance. For the initial investigations Acetobacter methanolicus and Methylobacterium rhodesianum were used. (orig.).

  10. 糯米炸糕中发酵细菌鉴定与优势菌株筛选%Identification of bacteria and screening of dominant strains from fermented glutinous rice

    Institute of Scientific and Technical Information of China (English)

    陈瑾; 邵冰洁; 朱晓昊; 王素英

    2016-01-01

    为筛选制作糯米炸糕的优势乳酸菌,从传统生产工艺的沥水米浆和发酵湿米粉中分离出7株细菌,经形态学观察、革兰氏染色反应、过氧化氢酶试验,以及葡萄糖发酵试验等生理生化特征考察,并分析菌株的16S rRNA序列.结果表明:菌株B1、B5-2、B7、B8为植物乳杆菌(Lactobacillus plantarum),B2为蜡状芽孢杆菌(Bacillus cereus),B5-1、B6为印度尼西亚醋酸杆菌(Acetobacter indonesiensis).通过测定4株乳酸菌的产酸能力和生长速度,发现菌株B5-2的生长速度和产酸能力较强.

  11. 微波结合盐酸羟铵诱变选育高产醋酸菌%Breeding of high yield acetic acid bacteria by hydroxylamine hydrochloride combined with microwave mutagenesis

    Institute of Scientific and Technical Information of China (English)

    贺小贤; 赵会芳; 孙福林; 刘苗苗

    2011-01-01

    以醋酸菌AFA-01为出发菌株,首先利用微波诱变菌株,之后再采用盐酸羟铵点式平板法处理,获得产酸性能较好的突变株AFA-WH3,其产酸量为7.35g/100mL,较出发菌株提高了43.55%,乙醇脱氢酶(ADH)活力达2786U/mL,较出发菌株提高94.83%.该菌株经8次传代,产酸稳定,可进行下一步的研究.%A high yield of acetic acid mutant strain Acetobacter pasteurianus AFA-WH3 was bred from its parent strain AFA-01 by hydroxylamine hy-drochloride combining with microwave mutagenesis. The results showed that the acetic acid production was increased by 43.55%, up to a concentration of 7.35 g/lOOml. Moreover, alcohol dehydrogenase(ADH) activities reached 2786U/ml, increased by 94.83%. The strain remained the characteristics of high acetic acid production after 8 times passage , and the mutant strain could be used as experiment strain for further studies.

  12. 一株高产酸醋酸菌的分离与鉴定%Screen and identification of an acetic acid bacteria having stable high acid productivity

    Institute of Scientific and Technical Information of China (English)

    宋勇强; 胡先望; 沙芮; 严晓娟; 张鸣明; 梁宁

    2015-01-01

    目的 从甘肃民间地产传统酿造食醋醋醅中分离筛选出一株高产酸醋酸菌并加以鉴定,为醋酸发酵提供新的菌种资源.方法 通过透明圈法和产醋酸定性试验等,对其中的醋酸菌进行分离,然后进行产酸量测定比较.结果 最终筛选出一株产酸量高且产量稳定的菌株A3,其产酸量为3.6468 g/100 mL.结论 根据菌株A3形态观察,再通过一系列生理生化试验,并结合16S rRNA分子生物学鉴定手段,最终鉴定其为醋酸杆菌属中的Acetobacter pomorum.

  13. Preliminary Study on Biosynthesis of Bacterial Nanocellulose Tubes in a Novel Double-Silicone-Tube Bioreactor for Potential Vascular Prosthesis

    Science.gov (United States)

    Wei, Bin; Chen, Lin

    2015-01-01

    Bacterial nanocellulose (BNC) has demonstrated a tempting prospect for applications in substitute of small blood vessels. However, present technology is inefficient in production and BNC tubes have a layered structure that may bring danger after implanting. Double oxygen-permeable silicone tubes in different diameters were therefore used as a tube-shape mold and also as oxygenated supports to construct a novel bioreactor for production of the tubular BNC materials. Double cannula technology was used to produce tubular BNC via cultivations with Acetobacter xylinum, and Kombucha, a symbiosis of acetic acid bacteria and yeasts. The results indicated that Kombucha gave higher yield and productivity of BNC than A. xylinum. Bacterial nanocellulose was simultaneously synthesized both on the inner surface of the outer silicone tube and on the outer surface of the inner silicone tube. Finally, the nano BNC fibrils from two directions formed a BNC tube with good structural integrity. Scanning electron microscopy inspection showed that the tubular BNC had a multilayer structure in the beginning but finally it disappeared and an intact BNC tube formed. The mechanical properties of BNC tubes were comparable with the reported value in literatures, demonstrating a great potential in vascular implants or in functional substitutes in biomedicine. PMID:26090420

  14. Bacterial Cellulose Membranes Used as Artificial Substitutes for Dural Defection in Rabbits

    Directory of Open Access Journals (Sweden)

    Chen Xu

    2014-06-01

    Full Text Available To improve the efficacy and safety of dural repair in neurosurgical procedures, a new dural material derived from bacterial cellulose (BC was evaluated in a rabbit model with dural defects. We prepared artificial dura mater using bacterial cellulose which was incubated and fermented from Acetobacter xylinum. The dural defects of the rabbit model were repaired with BC membranes. All surgeries were performed under sodium pentobarbital anesthesia, and all efforts were made to minimize suffering. All animals were humanely euthanized by intravenous injection of phenobarbitone, at each time point, after the operation. Then, the histocompatibility and inflammatory effects of BC were examined by histological examination, real-time fluorescent quantitative polymerase chain reaction (PCR and Western Blot. BC membranes evenly covered the surface of brain without adhesion. There were seldom inflammatory cells surrounding the membrane during the early postoperative period. The expression of inflammatory cytokines IL-1β, IL-6 and TNF-α as well as iNOS and COX-2 were lower in the BC group compared to the control group at 7, 14 and 21 days after implantation. BC can repair dural defects in rabbit and has a decreased inflammatory response compared to traditional materials. However, the long-term effects need to be validated in larger animals.

  15. Engineering of a novel carbonyl reductase with coenzyme regeneration in E. coli for efficient biosynthesis of enantiopure chiral alcohols.

    Science.gov (United States)

    Wei, Ping; Gao, Jia-Xin; Zheng, Gao-Wei; Wu, Hong; Zong, Min-Hua; Lou, Wen-Yong

    2016-07-20

    The novel anti-Prelog stereospecific carbonyl reductase from Acetobacter sp. CCTCC M209061 was successfully expressed in E. coli combined with glucose dehydrogenase (GDH) to construct an efficient whole-cell biocatalyst with coenzyme NADH regeneration. The enzymatic activity of GAcCR (AcCR with a GST tag) reached 304.9U/g-dcw, even 9 folds higher than that of wild strain, and the activity of GDH for NADH regeneration recorded 46.0U/mg-protein in the recombinant E. coli. As a whole-cell biocatalyst, the recombinant E. coli BL21(DE3)pLysS (pETDuet-gaccr-gdh) possessed a broad substrate spectrum for kinds of carbonyl compounds with encouraging yield and stereoselectivity. Besides, the asymmetric reduction of ethyl 4-chloroacetoacetate (COBE) to optically pure ethyl 4-chloro-3-hydroxybutyrate (CHBE) catalyzed by the whole-cell biocatalyst was systematically investigated. Under the optimal reaction conditions, the optical purity of CHBE was over 99% e.e. for (S)-enantiomer, and the initial rate and product yield reached 8.04μmol/min and 99.4%, respectively. Moreover, the space-time yield was almost 20 folds higher than that catalyzed by the wild strain. Therefore, a new, high efficiency biocatalyst for asymmetric reductions was constructed successfully, and the enantioselective reduction of prochiral compounds using the biocatalyst was a promising approach for obtaining enantiopure chiral alcohols. PMID:27211999

  16. 袋装变质食醋产膜菌的分离鉴定及其控制%Identification and controlling of producing membrane strains isolated from bagged deterioration vinegar

    Institute of Scientific and Technical Information of China (English)

    赵爽; 朱亚琴; 刘书亮; 张奶英; 韩新锋; 周康; 何利; 李建龙

    2014-01-01

    从货架期内袋装产膜醋中分离得到8株产膜菌,对其中两株代表菌株D23、D24,进行形态学特征和16S rDNA鉴定,并以这两株产膜菌为对象,研究不同酸度、热杀菌条件及防腐剂对其控制.结果表明,菌株D23为木葡糖醋酸杆菌(Gluconacetobacter oboediens),菌株D24为巴氏醋杆菌(Acetobacter pasteurianus);当食醋的酸度≥3.5g/100mL,2%接种量的产膜菌不能在食醋中生长繁殖并产膜;产膜菌的热致死条件是60℃ 10min;三种防腐剂(尼泊金乙酯、山梨酸钾、苯甲酸钠)对产膜菌产膜均有良好的抑制作用.

  17. Production of bacterial cellulose with controlled deuterium-hydrogen substitution for neutron scattering studies.

    Science.gov (United States)

    O'Neill, Hugh; Shah, Riddhi; Evans, Barbara R; He, Junhong; Pingali, Sai Venkatesh; Chundawat, Shishir P S; Jones, A Daniel; Langan, Paul; Davison, Brian H; Urban, Volker

    2015-01-01

    Isotopic enrichment of biomacromolecules is a widely used technique that enables the investigation of the structural and dynamic properties to provide information not accessible with natural abundance isotopic composition. This study reports an approach for deuterium incorporation into bacterial cellulose. A media formulation for growth of Acetobacter xylinus subsp. sucrofermentans and Gluconacetobacter hansenii was formulated that supports cellulose production in deuterium (D) oxide. The level of D incorporation can be varied by altering the ratio of deuterated and protiated glycerol used during cell growth in the D2O-based growth medium. Spectroscopic analysis and mass spectrometry show that the level of deuterium incorporation is high (>90%) for the perdeuterated form of bacterial cellulose. The small-angle neutron scattering profiles of the cellulose with different amounts of D incorporation are all similar indicating that there are no structural changes in the cellulose due to substitution of deuterium for hydrogen. In addition, by varying the amount of deuterated glycerol in the media it was possible to vary the scattering length density of the deuterated cellulose. The ability to control deuterium content of cellulose extends the range of experiments using techniques such as neutron scattering to reveal information about the structure and dynamics of cellulose, and its interactions with other biomacromolecules as well as synthetic polymers used for development of composite materials. PMID:26577730

  18. Microbially influenced corrosion communities associated with fuel-grade ethanol environments.

    Science.gov (United States)

    Williamson, Charles H D; Jain, Luke A; Mishra, Brajendra; Olson, David L; Spear, John R

    2015-08-01

    Microbially influenced corrosion (MIC) is a costly problem that impacts hydrocarbon production and processing equipment, water distribution systems, ships, railcars, and other types of metallic infrastructure. In particular, MIC is known to cause considerable damage to hydrocarbon fuel infrastructure including production, transportation, and storage systems, often times with catastrophic environmental contamination results. As the production and use of alternative fuels such as fuel-grade ethanol (FGE) increase, it is important to consider MIC of engineered materials exposed to these "newer fuels" as they enter existing infrastructure. Reports of suspected MIC in systems handling FGE and water prompted an investigation of the microbial diversity associated with these environments. Small subunit ribosomal RNA gene pyrosequencing surveys indicate that acetic-acid-producing bacteria (Acetobacter spp. and Gluconacetobacter spp.) are prevalent in environments exposed to FGE and water. Other microbes previously implicated in corrosion, such as sulfate-reducing bacteria and methanogens, were also identified. In addition, acetic-acid-producing microbes and sulfate-reducing microbes were cultivated from sampled environments containing FGE and water. Results indicate that complex microbial communities form in these FGE environments and could cause significant MIC-related damage that may be difficult to control. How to better manage these microbial communities will be a defining aspect of improving mitigation of global infrastructure corrosion. PMID:26092755

  19. Bioskin: A New Biomaterial for Therapeutical and Biotechnological Purposes

    Institute of Scientific and Technical Information of China (English)

    Xavier-Filho L

    2005-01-01

    @@ 1Results and Discussion Bioskin is new material by Acetobacter xylinum, Saccharomyces cerevisae and Schyzosaccharomyces pombe in mixed culture on sucrose. The Material has been revealed as hypoaller- genic,antibiotic,antithermic and sedative. It is widely used for skin regeneration in therapy of burns as well as in odontological surgery.Bioskin contains high amounts of D-glucosamine and N-acetyl-D-glucosamine. It does not produce ash after heating at 600 ℃ and its combustion heat is similar to that of several current woods, such as pine oak or maple Bioskin has been used to immobilize algal cells, fungal spores and Bacteria in order to study some metabolic events. In addition, immobilization, of several enzymes has been performed using bioskin as inert matrix.Catalase was immobilized at pH 7.0 by ionic adsorption (aminosugars provide a net positive charge neutral pH values) whereas several glycoproteins can be immobilized on bioskin by an affinity mechanism.

  20. Consumption of dietary sugar by gut bacteria determines Drosophila lipid content.

    Science.gov (United States)

    Huang, Jia-Hsin; Douglas, Angela E

    2015-09-01

    Gut microorganisms are essential for the nutritional health of many animals, but the underlying mechanisms are poorly understood. This study investigated how lipid accumulation by adult Drosophila melanogaster is reduced in flies associated with the bacterium Acetobacter tropicalis which displays oral-faecal cycling between the gut and food. We demonstrate that the lower lipid content of A. tropicalis-colonized flies relative to bacteria-free flies is linked with a parallel bacterial-mediated reduction in food glucose content; and can be accounted for quantitatively by the amount of glucose acquired by the flies, as determined from the feeding rate and assimilation efficiency of bacteria-free and A. tropicalis-colonized flies. We recommend that nutritional studies on Drosophila include empirical quantification of food nutrient content, to account for likely microbial-mediated effects on diet composition. More broadly, this study demonstrates that selective consumption of dietary constituents by microorganisms can alter the nutritional balance of food and, thereby, influence the nutritional status of the animal host. PMID:26382071

  1. Adaptability of microbial inoculators and their contribution to degradation of mineral oil and PAHs

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Five dominant bacteria strains(Acetobacter sp., Alcaligenes sp., Micrococcus sp., Arthrobacter sp. and Bacillus sp.) and five fungi strains (Cephalosporium sp. I, Cephalosporium sp. Ⅱ, Aspergillus sp. Ⅰ, Aspergillus sp. Ⅱ and Fusarium sp.) isolated from petroleum-contaminated soil were used to assess the potential capability of mineral oil and PAH enhanced degradation separately and jointly using the batch liquid medium cultivation with diesel oil spiked at 1000 mg/L. The experiment was performed on a reciprocal shaker in the darkness at 25℃ to 30℃ for 100 d. The dynamic variation in the activity of microbial inoculators in each treatment and the degradation of the target pollutants during the period of experiment were monitored. Results showed a more rapid biodegradation of mineral oil and PAHs at the beginning of the experiment (about 20 d) by dominant bacteria, fungi and their mixture than that of the indigenous microorganisms, however, thereafter an opposite trend was exhibited that the removal ratio by indigenous microorganisms was superior to any other dominant treatments and the tendency lasted till the end of the experiment, indicating the limited competitive capability of dominant microorganisms to degrade the contaminants, and the natural selection of indigenous microorganisms for use in the removal of the contaminants. At the end of the experiment, the removal ratio of mineral oil ranged from 56.8 % to 79.2 % and PAHs ranged from 96.8 % to 99.1% in each treatment by microbial inoculators.

  2. The Eschericia coli Growth Inhibition Activity of Some Fermented Medicinal Plant Leaf Extract from the Karo Highland, North Sumatra

    Directory of Open Access Journals (Sweden)

    NOVIK NURHIDAYAT

    2009-10-01

    Full Text Available A lot of traditional medicinal plant has antibacterial acitivities. Most of these plants are freshly chewed or grounded and used directly to treat infectious bacterial deseases. However, some practices employ a traditionally spontaneous fermentation on boiled extracted leaf, root or other parts of the plant. This work reports a laboratory stimulated spontaneous fermentation of leaf extracts from selected medicinal plants collected from the Karo Higland. The spontaenous fermentation was stimulated to be carried out by the Acetobacter xylinum and Saccharomyces cerevisiae. The anti-infectious agent activity was assayed on the Eschericia coli growth inhibition. A complementary non fermented leaf extract was also made and assayed as a comparative measure. Indeed, the fermented leaf extract of bitter bush (Eupatorium pallescens, cacao (Theobroma cacao, avocado (Persia gratissima, passion fruit (Passiflora edulis, cassava (Cassava utillissima, diamond flower (Hedyotis corymbosa, periwinkle (Catharanthus roseus, and gandarusa (Justicia gendarussa have relatively higher anti-E.coli acitivity than those of non fermented ones. However, there were no anti-E.coli activity was detected in both fermented and non fermented leaf extract of the guava (Psidium guajava and common betel (Piper nigrum.

  3. 宏基因组学技术分析传统食醋发酵过程微生物多样性%Metagenomic Analysis of Microbial Diversity in the Traditional Vinegar Fermentation Process

    Institute of Scientific and Technical Information of China (English)

    聂志强; 韩玥; 郑宇; 申雁冰; 王敏

    2013-01-01

    传统食醋具有悠久的历史,生产工艺独特,酿造过程中复杂的微生物群落及其代谢产物赋予了传统食醋独特的风味.采用宏基因组学技术对天津独流老醋醋酸发酵过程中细菌群落组成及其多样性进行分析.结果表明:在醋酸发酵前期细菌具有较高的多样性,主成分分析表明与醋酸发酵过程相关的细菌为乳杆菌属(Lactobacillus)、醋杆菌属(Acetobacter)和念珠藻属(Nostoc).随着醋酸发酵的进行,醋酸菌的含量呈增加趋势,乳酸菌的丰度降低,在整个醋酸发酵过程中乳酸菌的丰度远远高于其他细菌,说明乳酸菌可能对食醋的风味形成具有重要作用.

  4. Optimization performance of an AnSBBR applied to biohydrogen production treating whey.

    Science.gov (United States)

    Lima, D M F; Lazaro, C Z; Rodrigues, J A D; Ratusznei, S M; Zaiat, M

    2016-03-15

    The present study investigated the influence of the influent concentration of substrate, feeding time and temperature on the production of biohydrogen from cheese whey in an AnSBBR with liquid phase recirculation. The highest hydrogen yield (0.80 molH2.molLactose(-1)) and productivity (660 mLH2 L(-1) d(-1)) were achieved for influent concentrations of 5400 mgDQO L(-1). No significant difference was noted in the biological hydrogen production for the feeding time conditions analyzed. The lowest temperature tested (15 °C) promoted the highest hydrogen yield and productivity (1.12 molH2 molLactose(-1) and 1080 mLH2 L(-1) d(-1)), and for the highest temperature (45 °C), hydrogen production did not occur. The indicator values for the hydrogen production obtained with this configuration were higher than those obtained in other studies using traditional configurations such as UASBr and CSTR. A phylogenetic analysis showed that the majority of the analyzed clones were similar to Clostridium. In addition, clones phylogenetically similar to the Lactobacilaceae family, notably Lactobacillus rhamnosus, and clones with similar sequences to Acetobacter indonesiensis were observed in small proportion in the reactor.

  5. Research on the Application of Bacterial Cellulose in Papermaking%细菌纤维素在造纸工业中的应用

    Institute of Scientific and Technical Information of China (English)

    汤卫华; 贾士儒; 王芃; 殷海松

    2013-01-01

    细菌纤维素是由细菌产生的纯度很高的纳米级纤维素,具有结晶度和纯度高、机械强度大和生物相容性好等特点.在植物纤维中添加细菌纤维素,可改善纸张性能.细菌纤维素可用于制备特种纸和“电子纸”.%Bacterial cellulose (BC) is secreted by Acetobacter xylinum. Compared with plant fiber, it possesses an array of unique properties , including high crystallinity, high water content, biocompatibility, high mechanical strength and an ultra-fine fiber network. Bacterial cellulose can be used for making unusually strong paper, because it consists of extremely small clusters of cellulose microbrils, this property greatly upgrades the strength and durability of the paper when it is added to the paper. There are some issues in large-scale application of bacterial cellulose to be solved, such as the high cost, low yield, mechanical stability and so on.

  6. Study on the Microbial Community in Pit Mud by Fluorescence in situ Hybridization%荧光原位杂交(FISH)技术研究窖泥微生物群落

    Institute of Scientific and Technical Information of China (English)

    吴冬梅; 何翠容; 牛美灿; 彭昱雯; 郑佳; 金扬; 黄钧; 周荣清

    2012-01-01

    为了探索荧光原位杂交(FISH)技术,研究窖泥微生物群落结构特征多样性,进行了纯培养微生物及窖泥微生物的FISH检测。以Escherichia coli、Bacillus subtilis、Lactobacillus planetarium、Acetobacter rancens、Clostridiumacetobytylicum 5株不同种属的细菌为对象,研究了影响荧光原位杂交(FISH)技术对其定量表征的因素,并将该技术应用于窖泥微生物群落的研究。实验结果表明,E.coli及L.planetarium的定量表征受到生长期的影响,在对数和稳定期的菌体检出率〉82%,衰退期的L.planetarium则明显减少;死菌体比活菌体的检出信号显著减弱;经硫酸铝处理,除去腐植酸的窖泥样品明显地提高了可辨力,加入窖泥中的E.coli,FISH检出量为光学显微镜计数量的46.89%。采用FISH技术可视化定量表征了窖泥中细菌和古菌的特征,有益于从细胞水平研究其微生物群落的关系。%In order to investigate the diversity of microbial community in pit mud by fluorescence in situ hybrid- ization, detection of pure culture and samples were carried out. The influenced factors on FISH were studied based on five pure culture strains including Escheriehia coli, Bacillus subtilis, Lactobacillus planetarium, Acetobacter rancens, Clostridium acetobytylicum. Then the microbial community in pit mud was further investigated by the modified meth- od. The results showed that the quantitative characterization was influenced by growth phase. The detection rate was above 82% in logarithmic and stationary phases for E. coli and L. planetarium whereas was significantly less in death phase for L. planetarium. The detected fluorescentce signal of dead cells was rather weak than live cells. For E. coli added in pit mud samples, the resolution of FISH was improved significantly through removing humic acid by alumi- num sulfate, the recovery was 46. 89% of the direct microscopic somatic cell count. FISH could effectively character- ize

  7. Brewing Technology of Apple-Kiwifruit Vinegar%苹果猕猴桃混合型果醋酿造工艺

    Institute of Scientific and Technical Information of China (English)

    刘聪; 程圣恩; 孙浩; 郭攀峰; 严景恩; 史亚歌

    2011-01-01

    以苹果、猕猴桃为原料,对苹果猕猴桃混合果醋的酿造工艺进行研究.获得原料配比、酒精发酵和醋酸发酵的最佳工艺参数.原料配比为m(苹果汁)∶m(猕猴桃汁)=2∶1.酒精发酵的最佳参数为酵母菌接种量0.25%、发酵温度28 ℃、发酵时间7 d.醋酸发酵的最佳参数为酒精体积分数6%、醋酸菌接种量7%、发酵时间10 d.按以上工艺参数所得产品每100 mL总酸含量≥5.50 g,色泽鲜亮呈浅黄色,具有苹果果香,酸味柔和.%Using apple and kiwifruit as raw material, the brewing technology of vinegar was studied. The optimum ratio of apple to kiwifruit was 2:1 and conditions for alcoholic fermentation were started with inoculum of yeast by 0. 25% , fermented under 28℃ for 7days. The optimum acetic acid fermentation conditions were 6% initial alcohol concentration , 7% inoculum of acetobacter and 10 days fermentation. The appLe-kiwifruit vinegar looks pale yellow, and tastes soft with apple aroma.

  8. Change in the plasmid copy number in acetic acid bacteria in response to growth phase and acetic acid concentration.

    Science.gov (United States)

    Akasaka, Naoki; Astuti, Wiwik; Ishii, Yuri; Hidese, Ryota; Sakoda, Hisao; Fujiwara, Shinsuke

    2015-06-01

    Plasmids pGE1 (2.5 kb), pGE2 (7.2 kb), and pGE3 (5.5 kb) were isolated from Gluconacetobacter europaeus KGMA0119, and sequence analyses revealed they harbored 3, 8, and 4 genes, respectively. Plasmid copy numbers (PCNs) were determined by real-time quantitative PCR at different stages of bacterial growth. When KGMA0119 was cultured in medium containing 0.4% ethanol and 0.5% acetic acid, PCN of pGE1 increased from 7 copies/genome in the logarithmic phase to a maximum of 12 copies/genome at the beginning of the stationary phase, before decreasing to 4 copies/genome in the late stationary phase. PCNs for pGE2 and pGE3 were maintained at 1-3 copies/genome during all phases of growth. Under a higher concentration of ethanol (3.2%) the PCN for pGE1 was slightly lower in all the growth stages, and those of pGE2 and pGE3 were unchanged. In the presence of 1.0% acetic acid, PCNs were higher for pGE1 (10 copies/genome) and pGE3 (6 copies/genome) during the logarithmic phase. Numbers for pGE2 did not change, indicating that pGE1 and pGE3 increase their PCNs in response to acetic acid. Plasmids pBE2 and pBE3 were constructed by ligating linearized pGE2 and pGE3 into pBR322. Both plasmids were replicable in Escherichia coli, Acetobacter pasteurianus and G. europaeus, highlighting their suitability as vectors for acetic acid bacteria.

  9. Screening and characterization of ethanol-tolerant and thermotolerant acetic acid bacteria from Chinese vinegar Pei.

    Science.gov (United States)

    Chen, Yang; Bai, Ye; Li, Dongsheng; Wang, Chao; Xu, Ning; Hu, Yong

    2016-01-01

    Acetic acid bacteria (AAB) are important microorganisms in the vinegar industry. However, AAB have to tolerate the presence of ethanol and high temperatures, especially in submerged fermentation (SF), which inhibits AAB growth and acid yield. In this study, seven AAB that are tolerant to temperatures above 40 °C and ethanol concentrations above 10% (v/v) were isolated from Chinese vinegar Pei. All the isolated AAB belong to Acetobacter pasteurianus according to 16S rDNA analysis. Among all AAB, AAB4 produced the highest acid yield under high temperature and ethanol test conditions. At 4% ethanol and 30-40 °C temperatures, AAB4 maintained an alcohol-acid transform ratio of more than 90.5 %. High alcohol-acid transform ratio was still maintained even at higher temperatures, namely, 87.2, 77.1, 14.5 and 2.9% at 41, 42, 43 and 44 °C, respectively. At 30 °C and different initial ethanol concentrations (4-10%), the acid yield by AAB4 increased gradually, although the alcohol-acid transform ratio decreased to some extent. However, 46.5, 8.7 and 0.9% ratios were retained at ethanol concentrations of 11, 12 and 13%, respectively. When compared with AS1.41 (an AAB widely used in China) using a 10 L fermentor, AAB4 produced 42.0 g/L acetic acid at 37 °C with 10% ethanol, whereas AS1.41 almost stopped producing acetic acid. In conclusion, these traits suggest that AAB4 is a valuable strain for vinegar production in SF.

  10. Construction and use of a versatile set of broad-host-range cloning and expression vectors based on the RK2 replicon.

    Science.gov (United States)

    Blatny, J M; Brautaset, T; Winther-Larsen, H C; Haugan, K; Valla, S

    1997-01-01

    The plasmid vectors described in this report are derived from the broad-host-range RK2 replicon and can be maintained in many gram-negative bacterial species. The complete nucleotide sequences of all of the cloning and expression vectors are known. Important characteristics of the cloning vectors are as follows: a size range of 4.8 to 7.1 kb, unique cloning sites, different antibiotic resistance markers for selection of plasmid-containing cells, oriT-mediated conjugative plasmid transfer, plasmid stabilization functions, and a means for a simple method for modification of plasmid copy number. Expression vectors were constructed by insertion of the inducible Pu or Pm promoter together with its regulatory gene xylR or xylS, respectively, from the TOL plasmid of Pseudomonas putida. One of these vectors was used in an analysis of the correlation between phosphoglucomutase activity and amylose accumulation in Escherichia coli. The experiments showed that amylose synthesis was only marginally affected by the level of basal expression from the Pm promoter of the Acetobacter xylinum phosphoglucomutase gene (celB). In contrast, amylose accumulation was strongly reduced when transcription from Pm was induced. CelB was also expressed with a very high induction ratio in Xanthomonas campestris. These experiments showed that the A. xylinum celB gene could not complement the role of the bifunctional X. campestris phosphoglucomutase-phosphomannomutase gene in xanthan biosynthesis. We believe that the vectors described here are useful for cloning experiments, gene expression, and physiological studies with a wide range of bacteria and presumably also for analysis of gene transfer in the environment. PMID:9023917

  11. Effects of a cellulose mask synthesized by a bacterium on facial skin characteristics and user satisfaction

    Directory of Open Access Journals (Sweden)

    Amnuaikit T

    2011-06-01

    Full Text Available Thanaporn Amnuaikit, Toon Chusuit, Panithi Raknam, Prapaporn BoonmeDepartment of Pharmaceutical Technology, Faculty of Pharmaceutical Sciences, Prince of Songkla University, Songkhla, ThailandBackground: Cellulose masks obtained from natural sources such as bacteria are of interest as cosmetic devices for the treatment of dry skin because they not only improve hydration of the skin, but have low toxicity and are biodegradable. The aims of this study were to determine the in vivo effects of a cellulose mask obtained from Acetobacter xylinum on skin characteristics and to evaluate user satisfaction with the product.Methods: Thirty healthy Thai volunteers aged 21–40 years participated in the study. The volunteers were randomly separated into a control group and an experimental group. For the control group, volunteers were assigned to apply moist towels to the face for 25 minutes. For the experimental group, the volunteers were assigned to apply the masks, ie, translucent patches which could be fitted onto the face for the same period. The following week, the groups were changed over to the alternative treatment. Skin moisture, sebum, elasticity, texture, dullness, and desquamation levels were assessed using a system used for routine skin counseling before applying the trial product and five minutes after its removal. Degree of satisfaction with use of the cellulose mask was investigated using a five-point rating scale.Results: The cellulose mask increased moisture levels in the skin significantly more than moist towels (P < 0.05 after a single application. No obvious effects on other skin characteristics were found. The cellulose mask product rated around 4/5 on the satisfaction rating scale.Conclusions: A single application of the trial cellulose mask enhanced moisture uptake by facial skin. Users also reported being satisfied with the trial product.Keywords: bacterial cellulose, facial mask, skin characteristics, skin hydration, user

  12. Use of Phosphate Solubilizing Bacteria to Leach Rare Earth Elements from Monazite-Bearing Ore

    Directory of Open Access Journals (Sweden)

    Doyun Shin

    2015-04-01

    Full Text Available In the present study, the feasibility to use phosphate solubilizing bacteria (PSB to develop a biological leaching process of rare earth elements (REE from monazite-bearing ore was determined. To predict the REE leaching capacity of bacteria, the phosphate solubilizing abilities of 10 species of PSB were determined by halo zone formation on Reyes minimal agar media supplemented with bromo cresol green together with a phosphate solubilization test in Reyes minimal liquid media as the screening studies. Calcium phosphate was used as a model mineral phosphate. Among the test PSB strains, Pseudomonas fluorescens, P. putida, P. rhizosphaerae, Mesorhizobium ciceri, Bacillus megaterium, and Acetobacter aceti formed halo zones, with the zone of A. aceti being the widest. In the phosphate solubilization test in liquid media, Azospirillum lipoferum, P. rhizosphaerae, B. megaterium, and A. aceti caused the leaching of 6.4%, 6.9%, 7.5%, and 32.5% of calcium, respectively. When PSB were used to leach REE from monazite-bearing ore, ~5.7 mg/L of cerium (0.13% of leaching efficiency and ~2.8 mg/L of lanthanum (0.11% were leached by A. aceti, and Azospirillum brasilense, A. lipoferum, P. rhizosphaerae and M. ciceri leached 0.5–1 mg/L of both cerium and lanthanum (0.005%–0.01%, as measured by concentrations in the leaching liquor. These results indicate that determination of halo zone formation was found as a useful method to select high-capacity bacteria in REE leaching. However, as the leaching efficiency determined in our experiments was low, even in the presence of A. aceti, further studies are now underway to enhance leaching efficiency by selecting other microorganisms based on halo zone formation.

  13. Microbial Dynamics during Aerobic Exposure of Corn Silage Stored under Oxygen Barrier or Polyethylene Films▿

    Science.gov (United States)

    Dolci, Paola; Tabacco, Ernesto; Cocolin, Luca; Borreani, Giorgio

    2011-01-01

    The aims of this study were to compare the effects of sealing forage corn with a new oxygen barrier film with those obtained by using a conventional polyethylene film. This comparison was made during both ensilage and subsequent exposure of silage to air and included chemical, microbiological, and molecular (DNA and RNA) assessments. The forage was inoculated with a mixture of Lactobacillus buchneri, Lactobacillus plantarum, and Enterococcus faecium and ensiled in polyethylene (PE) and oxygen barrier (OB) plastic bags. The oxygen permeability of the PE and OB films was 1,480 and 70 cm3 m−2 per 24 h at 23°C, respectively. The silages were sampled after 110 days of ensilage and after 2, 5, 7, 9, and 14 days of air exposure and analyzed for fermentation characteristics, conventional microbial enumeration, and bacterial and fungal community fingerprinting via PCR-denaturing gradient gel electrophoresis (DGGE) and reverse transcription (RT)-PCR-DGGE. The yeast counts in the PE and OB silages were 3.12 and 1.17 log10 CFU g−1, respectively, with corresponding aerobic stabilities of 65 and 152 h. Acetobacter pasteurianus was present at both the DNA and RNA levels in the PE silage samples after 2 days of air exposure, whereas it was found only after 7 days in the OB silages. RT-PCR-DGGE revealed the activity of Aspergillus fumigatus in the PE samples from the day 7 of air exposure, whereas it appeared only after 14 days in the OB silages. It has been shown that the use of an oxygen barrier film can ensure a longer shelf life of silage after aerobic exposure. PMID:21821764

  14. Occurrence of Cellulose-Producing Gluconacetobacter spp. in Fruit Samples and Kombucha Tea, and Production of the Biopolymer.

    Science.gov (United States)

    Neera; Ramana, Karna Venkata; Batra, Harsh Vardhan

    2015-06-01

    Cellulose producing bacteria were isolated from fruit samples and kombucha tea (a fermented beverage) using CuSO4 solution in modified Watanabe and Yamanaka medium to inhibit yeasts and molds. Six bacterial strains showing cellulose production were isolated and identified by 16S rRNA gene sequencing as Gluconacetobacter xylinus strain DFBT, Ga. xylinus strain dfr-1, Gluconobacter oxydans strain dfr-2, G. oxydans strain dfr-3, Acetobacter orientalis strain dfr-4, and Gluconacetobacter intermedius strain dfr-5. All the cellulose-producing bacteria were checked for the cellulose yield. A potent cellulose-producing bacterium, i.e., Ga. xylinus strain DFBT based on yield (cellulose yield 5.6 g/L) was selected for further studies. Cellulose was also produced in non- conventional media such as pineapple juice medium and hydrolysed corn starch medium. A very high yield of 9.1 g/L cellulose was obtained in pineapple juice medium. Fourier transform infrared spectrometer (FT-IR) analysis of the bacterial cellulose showed the characteristic peaks. Soft cellulose with a very high water holding capacity was produced using limited aeration. Scanning electron microscopy (SEM) was used to analyze the surface characteristics of normal bacterial cellulose and soft cellulose. The structural analysis of the polymer was performed using (13)C solid-state nuclear magnetic resonance (NMR). More interfibrillar space was observed in the case of soft cellulose as compared to normal cellulose. This soft cellulose can find potential applications in the food industry as it can be swallowed easily without chewing.

  15. N-acetylglucosamine 6-phosphate deacetylase (nagA is required for N-acetyl glucosamine assimilation in Gluconacetobacter xylinus.

    Directory of Open Access Journals (Sweden)

    Vikas Yadav

    Full Text Available Metabolic pathways for amino sugars (N-acetylglucosamine; GlcNAc and glucosamine; Gln are essential and remain largely conserved in all three kingdoms of life, i.e., microbes, plants and animals. Upon uptake, in the cytoplasm these amino sugars undergo phosphorylation by phosphokinases and subsequently deacetylation by the enzyme N-acetylglucosamine 6-phosphate deacetylase (nagA to yield glucosamine-6-phosphate and acetate, the first committed step for both GlcNAc assimilation and amino-sugar-nucleotides biosynthesis. Here we report the cloning of a DNA fragment encoding a partial nagA gene and its implications with regard to amino sugar metabolism in the cellulose producing bacterium Glucoacetobacter xylinus (formally known as Acetobacter xylinum. For this purpose, nagA was disrupted by inserting tetracycline resistant gene (nagA::tet(r; named as ΔnagA via homologous recombination. When compared to glucose fed conditions, the UDP-GlcNAc synthesis and bacterial growth (due to lack of GlcNAc utilization was completely inhibited in nagA mutants. Interestingly, that inhibition occured without compromising cellulose production efficiency and its molecular composition under GlcNAc fed conditions. We conclude that nagA plays an essential role for GlcNAc assimilation by G. xylinus thus is required for the growth and survival for the bacterium in presence of GlcNAc as carbon source. Additionally, G. xylinus appears to possess the same molecular machinery for UDP-GlcNAc biosynthesis from GlcNAc precursors as other related bacterial species.

  16. Biosynthetic bacterial cellulose graft as arteriovenous fistula and ndash; a complement to existing synthetic grafts?

    Directory of Open Access Journals (Sweden)

    Johan Magnusson

    2016-06-01

    Materials and Methods: As graftmaterial bacterial cellulose was used, produced around a preformed scaffold. Bacterial cellulose (BC is a material produced by the bacteria acetobacter xylinum. A pilotstudy was conducted on 6 pigs to validate the animalmodel and the new graftmaterial. In the following survival study a BC-graft AV-fistula was constructed in 15 pigs. Results: In the pilot study, 5 out of 6 animals had a patent AV-fistula 4 hours after implantation. In the survival study, after 4 (n3 and 8 (n10 weeks an angiography was performed prior to explantation of the BC-graft. All grafts were occluded with a presumed platelet plug. We conducted an additional acute patch-test comparing the BC and expanded PolyTetraFluoro- Ethylene. A patch of BC and ePTFE was applied to the right and left common femoral artery respectively. At explantation three hours later, all BC-patches showed a thin gel like layer, most likely consisting of platelets, throughout the whole sur- face while the ePTFE-patch showed no, or minimal, signs of platelet adhesions. Conclusion: Theoretically the cellulose might be similar to autologous veins considering risk of infections and thrombo- genicity. The animal model and the graft material showed good potential in the pilot study. The survival study was discour- aging with the reason for occlusion still to be explained. Bacterial cellulose has a good potential but further development and studies need to be performed. [Arch Clin Exp Surg 2016; 5(2.000: 70-77

  17. Functional dissection of the bipartite active site of the class I coenzyme A (CoA)-transferase succinyl-CoA:acetate CoA-transferase

    Science.gov (United States)

    Murphy, Jesse; Mullins, Elwood; Kappock, T.

    2016-05-01

    Coenzyme A (CoA)-transferases catalyze the reversible transfer of CoA from acyl-CoA thioesters to free carboxylates. Class I CoA-transferases produce acylglutamyl anhydride intermediates that undergo attack by CoA thiolate on either the internal or external carbonyl carbon atoms, forming distinct tetrahedral intermediates less than 3 Å apart. In this study, crystal structures of succinyl-CoA:acetate CoA-transferase (AarC) from Acetobacter aceti are used to examine how the Asn347 carboxamide stabilizes the internal oxyanion intermediate. A structure of the active mutant AarC-N347A bound to CoA revealed both solvent replacement of the missing contact and displacement of the adjacent Glu294, indicating that Asn347 both polarizes and orients the essential glutamate. AarC was crystallized with the nonhydrolyzable acetyl-CoA (AcCoA) analogue dethiaacetyl-CoA (1a) in an attempt to trap a closed enzyme complex containing a stable analogue of the external oxyanion intermediate. One active site contained an acetylglutamyl anhydride adduct and truncated 1a, an unexpected result hinting at an unprecedented cleavage of the ketone moiety in 1a. Solution studies confirmed that 1a decomposition is accompanied by production of near-stoichiometric acetate, in a process that seems to depend on microbial contamination but not AarC. A crystal structure of AarC bound to the postulated 1a truncation product (2a) showed complete closure of one active site per dimer but no acetylglutamyl anhydride, even with acetate added. These findings suggest that an activated acetyl donor forms during 1a decomposition; a working hypothesis involving ketone oxidation is offered. The ability of 2a to induce full active site closure furthermore suggests that it subverts a system used to impede inappropriate active site closure on unacylated CoA.

  18. Isolation, Characterization and Application of Bacterial Population From Agricultural Soil at Sohag Province, Egypt

    Directory of Open Access Journals (Sweden)

    Bahig, A. E.

    2008-01-01

    Full Text Available Forty soil samples of agriculture soil were collected from two different sites in Sohag province, Egypt, during hot and cold seasons. Twenty samples were from soil irrigated with canal water (site A and twenty samples were from soil irrigated with wastewater (site B. This study aimed to compare the incidence of plasmids in bacteria isolated from soil and to investigate the occurrence of metal and antibiotic resistance bacteria, and consequently to select the potential application of these bacteria in bioremediation. The total bacterial count (CFU/gm in site (B was higher than that in site (A. Moreover, the CFU values in summer were higher than those values in winter at both sites. A total of 771 bacterial isolates were characterized as Bacillus, Micrococcus, Staphylococcus, Pseudomonas, Eschershia, Shigella, Xanthomonas, Acetobacter, Citrobacter, Enterobacter, Moraxella and Methylococcus. Minimum inhibitory concentrations (MICs of Pb+2, Cu+2, Zn+2, Hg+2, Co+2, Cd+2, Cr+3, Te+2, As+2 and Ni+2 for plasmid-possessed bacteria were determined and the highest MICs were 1200 µg/mL for lead, 800 µg/mL for both Cobalt and Arsenate, 1200 µg/mL for Nickel, 1000 µg/ml for Copper and less than 600 µg/mL for other metals. Bacterial isolates from both sites A and B showed multiple heavy metal resistance. A total of 337 bacterial isolates contained plasmids and the incidence of plasmids was approximately 25-50% higher in bacteria isolated from site (B than that from site (A. These isolates were resistance to different antibiotics. Approximately, 61% of the bacterial isolates were able to assimilate insecticide, carbaryl, as a sole source of carbon and energy. However, the Citrobacter AA101 showed the best growth on carbaryl.

  19. Microbes of fermented kefir-like using combination of kefir grains and Bifidobacterium longum

    Directory of Open Access Journals (Sweden)

    Sri Usmiati

    2005-03-01

    Full Text Available The objectives of research were to find out physico-chemical characters and to detect flavor volatile compound of kefir-like. Material used was skim milk TS 9.5% which was heated at 85oC for 30 minutes and cooled at 22oC before innoculation of the starter. Microorganisms used were (a Lactobacillus acidophilus P155110, (b Lactobacillus delbrueckii subsp. Bulgaricus NCIMB 11778, (c Lactococcus lactis P155610, (d Leuconostoc mesenteroides subsp. dextranicum NCIMB 3350, (e Acetobacter aceti P154810, (f Bifidobacterium longum BF1, and (g Saccharomyces cerevisiae P156252. The treatments consist of P1 = without (b; P2 = without (a; and P3= used (a until (g. The physico-chemical characters identified were lactic acid and lactose percentages, pH, viscosity, organoleptic test for intensity of kefir-like sensory attributes. Results indicated that B. longum was potential bacterium use for starter combination on kefir-like making. The use starter P1 combination has high acidity and viscosity, low pH and lactose percentage, and high intensity on attribute creamy-white color, soft and curdle consistency, and kefir specific aroma on kefir-like. Volatile compound acid group were dominate by high acidity character on kefir-like resulted from starter P1 combination. Compound of 3-hydroxi-2-butanone (acetoin was affecting butter-like of P3 character. This compound resulted from which is a character of fermented milk flavor was not detected on P1 kefir-like.

  20. Bacterial microbiota compositions of naturally fermented milk are shaped by both geographic origin and sample type.

    Science.gov (United States)

    Zhong, Z; Hou, Q; Kwok, L; Yu, Z; Zheng, Y; Sun, Z; Menghe, B; Zhang, H

    2016-10-01

    Naturally fermented dairy products contain a rich microbial biodiversity. This study aimed to provide an overview on the bacterial microbiota biodiversity of 85 samples, previously collected across a wide region of China, Mongolia, and Russia. Data from these 85 samples, including 55 yogurts, 18 naturally fermented yak milks, 6 koumisses, and 6 cheeses, were retrieved and collectively analyzed. The most prevalent phyla shared across samples were Firmicutes, Proteobacteria, Bacteroidetes, and Actinobacteria, which together accounted for 99% of bacterial sequences. The predominant genera were Lactobacillus, Lactococcus, Streptococcus, Acetobacter, Acinetobacter, Leuconostoc, and Macrococcus, which together corresponded to 96.63% of bacterial sequences. Further multivariate statistical analyses revealed significant differences in the microbiota structure across sample geographic origin and type. First, on the principal coordinate score plot, samples representing the 3 main sample collection regions (Russia, Xinjiang, and Tibet) were mostly located respectively in the upper left, lower right, and lower left quadrants, although slight overlapping occurred. In contrast, samples from the minor sampling areas (Inner Mongolia, Mongolia, Gansu, and Sichuan) were predominantly distributed in the lower left quadrant. These results suggest a possible association between sample geographical origin and microbiota composition. Second, bacterial microbiota structure was stratified by sample type. In particular, the microbiota of cheese was largely distinct from the other sample types due to its high abundances of Lactococcus and Streptococcus. The fermented yak milk microbiota was most like that of the yogurts. Koumiss samples had the lowest microbial diversity and richness. In conclusion, both geographic origin and sample type shape the microbial diversity of naturally fermented milk. PMID:27474988

  1. Prokaryotic Diversity in the Rhizosphere of Organic, Intensive, and Transitional Coffee Farms in Brazil.

    Science.gov (United States)

    Caldwell, Adam Collins; Silva, Lívia Carneiro Fidéles; da Silva, Cynthia Canêdo; Ouverney, Cleber Costa

    2015-01-01

    Despite a continuous rise in consumption of coffee over the past 60 years and recent studies showing positive benefits linked to human health, intensive coffee farming practices have been associated with environmental damage, risks to human health, and reductions in biodiversity. In contrast, organic farming has become an increasingly popular alternative, with both environmental and health benefits. This study aimed to characterize and determine the differences in the prokaryotic soil microbiology of three Brazilian coffee farms: one practicing intensive farming, one practicing organic farming, and one undergoing a transition from intensive to organic practices. Soil samples were collected from 20 coffee plant rhizospheres (soil directly influenced by the plant root exudates) and 10 control sites (soil 5 m away from the coffee plantation) at each of the three farms for a total of 90 samples. Profiling of 16S rRNA gene V4 regions revealed high levels of prokaryotic diversity in all three farms, with thousands of species level operational taxonomic units identified in each farm. Additionally, a statistically significant difference was found between each farm's coffee rhizosphere microbiome, as well as between coffee rhizosphere soils and control soils. Two groups of prokaryotes associated with the nitrogen cycle, the archaeal genus Candidatus Nitrososphaera and the bacterial order Rhizobiales were found to be abundant and statistically different in composition between the three farms and in inverse relationship to each other. Many of the nitrogen-fixing genera known to enhance plant growth were found in low numbers (e.g. Rhizobium, Agrobacter, Acetobacter, Rhodospirillum, Azospirillum), but the families in which they belong had some of the highest relative abundance in the dataset, suggesting many new groups may exist in these samples that can be further studied as potential plant growth-promoting bacteria to improve coffee production while diminishing negative

  2. Bacterial diversity of floor drain biofilms and drain waters in a Listeria monocytogenes contaminated food processing environment.

    Science.gov (United States)

    Dzieciol, Monika; Schornsteiner, Elisa; Muhterem-Uyar, Meryem; Stessl, Beatrix; Wagner, Martin; Schmitz-Esser, Stephan

    2016-04-16

    Sanitation protocols are applied on a daily basis in food processing facilities to prevent the risk of cross-contamination with spoilage organisms. Floor drain water serves along with product-associated samples (slicer dust, brine or cheese smear) as an important hygiene indicator in monitoring Listeria monocytogenes in food processing facilities. Microbial communities of floor drains are representative for each processing area and are influenced to a large degree by food residues, liquid effluents and washing water. The microbial communities of drain water are steadily changing, whereas drain biofilms provide more stable niches. Bacterial communities of four floor drains were characterized using 16S rRNA gene pyrosequencing to better understand the composition and exchange of drain water and drain biofilm communities. Furthermore, the L. monocytogenes contamination status of each floor drain was determined by applying cultivation-independent real-time PCR quantification and cultivation-dependent detection according to ISO11290-1. Pyrosequencing of 16S rRNA genes of drain water and drain biofilm bacterial communities yielded 50,611 reads, which were clustered into 641 operational taxonomic units (OTUs), affiliated to 16 phyla dominated by Proteobacteria, Firmicutes and Bacteroidetes. The most abundant OTUs represented either product- (Lactococcus lactis) or fermentation- and food spoilage-associated phylotypes (Pseudomonas mucidolens, Pseudomonas fragi, Leuconostoc citreum, and Acetobacter tropicalis). The microbial communities in DW and DB samples were distinct in each sample type and throughout the whole processing plant, indicating the presence of indigenous specific microbial communities in each processing compartment. The microbiota of drain biofilms was largely different from the microbiota of the drain water. A sampling approach based on drain water alone may thus only provide reliable information on planktonic bacterial cells but might not allow conclusions

  3. Influence of air flow, temperature and agitation speed in the batch acetification process to obtain orange vinegar (Citrus sinensis var.W. Navel

    Directory of Open Access Journals (Sweden)

    María Ferreyra

    2012-03-01

    Full Text Available This paper describes the influence of process variables to produce orange vinegar. Orange juice was fermented with Saccharomyces cerevisiae until reach 14% v/v. The biooxidation was carried out with Acetobacter sp., in submerge culture using a laboratory scale fermentor. In order to avoid the inhibitory effect of ethanol on acetic acid bacteria, the orange wine was diluted to 6% v/v with a mineral solution. It was performed a factorial design 2k to study the influence of variables. It was studied air flow rate/agitation at levels of 0.3-0.6 vvm and 200-400 rpm and the effect of air flow rate/temperature at 0.4-0.6 vvm and 25- 30°C, respectively. Duplicate treatments were carried out and the results were evaluated in terms of productivity and fermentation yield. Statistical design (p-value<0.05 was analyzed using Statgraphics Centurion XV Corporate software. Treatments performed at 200 rpm and different air flow levels, did not show significant differences on acetification rate. At higher agitation speed and air flow rates, the productivity was high. The best yields were obtained at lower air flows levels and higher agitation speed. Temperature did not present statistically differences on studied variables. The best yield was obtained at 400 rpm and 0.3 vvm at 25°C. It can be concluded that agitation speed plays an important role for a better acetification rate however higher air flow rates causes less yields.

  4. Bacterial diversity of floor drain biofilms and drain waters in a Listeria monocytogenes contaminated food processing environment.

    Science.gov (United States)

    Dzieciol, Monika; Schornsteiner, Elisa; Muhterem-Uyar, Meryem; Stessl, Beatrix; Wagner, Martin; Schmitz-Esser, Stephan

    2016-04-16

    Sanitation protocols are applied on a daily basis in food processing facilities to prevent the risk of cross-contamination with spoilage organisms. Floor drain water serves along with product-associated samples (slicer dust, brine or cheese smear) as an important hygiene indicator in monitoring Listeria monocytogenes in food processing facilities. Microbial communities of floor drains are representative for each processing area and are influenced to a large degree by food residues, liquid effluents and washing water. The microbial communities of drain water are steadily changing, whereas drain biofilms provide more stable niches. Bacterial communities of four floor drains were characterized using 16S rRNA gene pyrosequencing to better understand the composition and exchange of drain water and drain biofilm communities. Furthermore, the L. monocytogenes contamination status of each floor drain was determined by applying cultivation-independent real-time PCR quantification and cultivation-dependent detection according to ISO11290-1. Pyrosequencing of 16S rRNA genes of drain water and drain biofilm bacterial communities yielded 50,611 reads, which were clustered into 641 operational taxonomic units (OTUs), affiliated to 16 phyla dominated by Proteobacteria, Firmicutes and Bacteroidetes. The most abundant OTUs represented either product- (Lactococcus lactis) or fermentation- and food spoilage-associated phylotypes (Pseudomonas mucidolens, Pseudomonas fragi, Leuconostoc citreum, and Acetobacter tropicalis). The microbial communities in DW and DB samples were distinct in each sample type and throughout the whole processing plant, indicating the presence of indigenous specific microbial communities in each processing compartment. The microbiota of drain biofilms was largely different from the microbiota of the drain water. A sampling approach based on drain water alone may thus only provide reliable information on planktonic bacterial cells but might not allow conclusions

  5. Utilization of Tritium and Carbon-14 in Studies of Isotope Effects

    International Nuclear Information System (INIS)

    The utility of tritium in organic research has been augmented by the development of a simple method for determining C14 and tritium in the same sample. The non-volatile, radioactive material, in a film that is 'infinitely thick' to tritium radiation, is counted in a windowless, gas-fiow proportional counter; the film is then re-counted when covered with a screen that stops all radiation from tritium but allows a fraction of that from C14 to pass. By introduction of one isotope at a point removed from the reaction centre, an isotope effect for the other can be determined from changes in the tritium-C14 ratio in the reactant and/or products as the reaction proceeds. Carriers of reactant, products or derivatives can be added at any point to facilitate isolation, because the analytical method depends primarily on the tritium-C14 ratio. Methods for utilizing the double-label technique will be illustrated by a study of isotope effects in the oxidation of the penultimate carbon of certain labelled polyols with Acetobacter suboxydans. Six D-mannitols position-labelled either with C14 or with tritium at C1, C2 or C3 were prepared. For these, isotope effects (k*/k) of 0.93, 0.23, and 0.71, respectively, were found with C14 at C2, tritium at C2, and tritium at C3; no detectable isotope effects were found for the remaining Dmannitols. In the oxidation of position-labelled D-glucitols, an isotope effect of 0.24 was found for tritium at C5; no detectable effect was found for either C14 or tritium at C1. The techniques are suitable for studying a variety of chemical and biological reactions. (author)

  6. Bacaba beverage produced by Umutina Brazilian Amerindians: Microbiological and chemical characterization

    Directory of Open Access Journals (Sweden)

    Cláudia Puerari

    2015-01-01

    Full Text Available Bacaba chicha is a beverage prepared by the indigenous Umutina people from the bacaba fruit (Oenocarpus bacaba, a purple berry that is rich in fat and carbohydrates, as well as a source of phenolic compounds. In this study, samples of bacaba chicha beverage were collected, and the microbial community was assessed using culture-dependent and -independent techniques. The nutritional composition and metabolite profiles were analyzed, and species belonging to lactic acid bacteria (LAB and yeasts were detected. The LAB group detected by culture-dependent analysis included Enterococcus hormaechei and Leuconostoc lactis. Polymerase chain reaction and denaturing gradient gel electrophoresis (PCR-DGGE detected additional Propionibacterium avidum, Acetobacter spp., and uncultured bacteria. Pichia caribbica and Pichia guilliermondii were detected in a culture-dependent method, and Pichia caribbica was confirmed by PCR-DGGE analysis. The pH value of the beverage was 6.2. The nutritional composition was as follows: 16.47 ± 0.73 g 100 mL-1dry matter, 2.2 ± 0.0 g 100 mL-1 fat, 3.36 ± 0.44 g 100 mL-1 protein, and 10.87 ± 0.26 g 100 mL-1carbohydrate. The metabolites detected were 2.69 g L-1 succinic acid, 0.9 g L-1 acetic acid, 0.49 g L-1 citric acid, 0.52 g L-1ethanol, and 0.4 g L-1 glycerol. This is the first study to identify microbial diversity in bacaba chicha spontaneous fermentation. This study is also the starting step in the immaterial record of this Brazilian indigenous beverage prepared from bacaba fruit.

  7. Biological nitrogen fixation in sugar cane: A key to energetically viable biofuel production

    Energy Technology Data Exchange (ETDEWEB)

    Boddey, R.M. [Centro Nacional de Pesquisa de Agrobiologia, Rio de Janeiro (Brazil)

    1995-05-01

    The advantages of producing biofuels to replace fossil energy sources are derived from the fact that the energy accumulated in the biomass in captured directly from photosynthesis and is thus renewable, and that the cycle of carbon dioxide fixation by the crop, followed by burning of the fuel makes no overall contribution to atmospheric CO{sub 2} or, consequently, to global warming. However, these advantages are negated if large quantities of fossil fuels need to be used to grow or process the biofuel crop. In this regard, the Brazilian bioethanol program, based on the fermentation/distillation of sugar cane juice, is particularly favorable, not only because the crop is principally hand harvested, but also because of the low nitrogen fertilizer use on sugar cane in Brazil. Recent {sup 15}N and N balance studies have shown that in some Brazilian cane varieties, high yields are possible without N fertilization because the plants are able to obtain large contributions of nitrogen from plant-associated biological N{sub 2} fixation (BNF). The N{sub 2}-fixing acid-tolerant bacterium Acetobacter diazotrophicus was first found to occur within roots, stems, and leaves of sugar cane. Subsequently, two species of Herbaspirillum also have been found to occur within the interior of all sugar cane tissues. The discovery of these, and other N{sub 2}-fixing bacteria that survive poorly in soil but thrive within plant tissue (endophytic bacteria), may account for the high BNF contributions observed in sugar cane. Further study of this system should allow the gradual elimination of N fertilizer use on sugar cane, at least in Brazil, and opens up the possibility of the extension of this efficient N{sub 2}-fixing system to cereal and other crops with consequent immense potential benefits to tropical agriculture. 44 refs., 9 figs., 4 tabs.

  8. In vivo function and comparative genomic analyses of the Drosophila gut microbiota identify candidate symbiosis factors

    Directory of Open Access Journals (Sweden)

    Peter David Newell

    2014-11-01

    Full Text Available Symbiosis is often characterized by co-evolutionary changes in the genomes of the partners involved. An understanding of these changes can provide insight into the nature of the relationship, including the mechanisms that initiate and maintain an association between organisms. In this study we examined the genome sequences of bacteria isolated from the Drosophila melanogaster gut with the objective of identifying genes that are important for function in the host. We compared microbiota isolates with con-specific or closely related bacterial species isolated from non-fly environments. First the phenotype of germ-free Drosophila (axenic flies was compared to that of flies colonized with specific bacteria (gnotobiotic flies as a measure of symbiotic function. Non-fly isolates were functionally distinct from bacteria isolated from flies, conferring slower development and an altered nutrient profile in the host, traits known to be microbiota-dependent. Comparative genomic methods were next employed to identify putative symbiosis factors: genes found in bacteria that restore microbiota-dependent traits to gnotobiotic flies, but absent from those that do not. Factors identified include riboflavin synthesis and stress resistance. We also used a phylogenomic approach to identify protein coding genes for which fly-isolate sequences were more similar to each other than to other sequences, reasoning that these genes may have a shared function unique to the fly environment. This method identified genes in Acetobacter species that cluster in two distinct genomic loci: one predicted to be involved in oxidative stress detoxification and another encoding an efflux pump. In summary, we leveraged genomic and in vivo functional comparisons to identify candidate traits that distinguish symbiotic bacteria. These candidates can serve as the basis for further work investigating the genetic requirements of bacteria for function and persistence in the Drosophila gut.

  9. Function and X-ray crystal structure of Escherichia coli YfdE.

    Directory of Open Access Journals (Sweden)

    Elwood A Mullins

    Full Text Available Many food plants accumulate oxalate, which humans absorb but do not metabolize, leading to the formation of urinary stones. The commensal bacterium Oxalobacter formigenes consumes oxalate by converting it to oxalyl-CoA, which is decarboxylated by oxalyl-CoA decarboxylase (OXC. OXC and the class III CoA-transferase formyl-CoA:oxalate CoA-transferase (FCOCT are widespread among bacteria, including many that have no apparent ability to degrade or to resist external oxalate. The EvgA acid response regulator activates transcription of the Escherichia coli yfdXWUVE operon encoding YfdW (FCOCT, YfdU (OXC, and YfdE, a class III CoA-transferase that is ~30% identical to YfdW. YfdW and YfdU are necessary and sufficient for oxalate-induced protection against a subsequent acid challenge; neither of the other genes has a known function. We report the purification, in vitro characterization, 2.1-Å crystal structure, and functional assignment of YfdE. YfdE and UctC, an orthologue from the obligate aerobe Acetobacter aceti, perform the reversible conversion of acetyl-CoA and oxalate to oxalyl-CoA and acetate. The annotation of YfdE as acetyl-CoA:oxalate CoA-transferase (ACOCT expands the scope of metabolic pathways linked to oxalate catabolism and the oxalate-induced acid tolerance response. FCOCT and ACOCT active sites contain distinctive, conserved active site loops (the glycine-rich loop and the GNxH loop, respectively that appear to encode substrate specificity.

  10. Prokaryotic Diversity in the Rhizosphere of Organic, Intensive, and Transitional Coffee Farms in Brazil.

    Directory of Open Access Journals (Sweden)

    Adam Collins Caldwell

    Full Text Available Despite a continuous rise in consumption of coffee over the past 60 years and recent studies showing positive benefits linked to human health, intensive coffee farming practices have been associated with environmental damage, risks to human health, and reductions in biodiversity. In contrast, organic farming has become an increasingly popular alternative, with both environmental and health benefits. This study aimed to characterize and determine the differences in the prokaryotic soil microbiology of three Brazilian coffee farms: one practicing intensive farming, one practicing organic farming, and one undergoing a transition from intensive to organic practices. Soil samples were collected from 20 coffee plant rhizospheres (soil directly influenced by the plant root exudates and 10 control sites (soil 5 m away from the coffee plantation at each of the three farms for a total of 90 samples. Profiling of 16S rRNA gene V4 regions revealed high levels of prokaryotic diversity in all three farms, with thousands of species level operational taxonomic units identified in each farm. Additionally, a statistically significant difference was found between each farm's coffee rhizosphere microbiome, as well as between coffee rhizosphere soils and control soils. Two groups of prokaryotes associated with the nitrogen cycle, the archaeal genus Candidatus Nitrososphaera and the bacterial order Rhizobiales were found to be abundant and statistically different in composition between the three farms and in inverse relationship to each other. Many of the nitrogen-fixing genera known to enhance plant growth were found in low numbers (e.g. Rhizobium, Agrobacter, Acetobacter, Rhodospirillum, Azospirillum, but the families in which they belong had some of the highest relative abundance in the dataset, suggesting many new groups may exist in these samples that can be further studied as potential plant growth-promoting bacteria to improve coffee production while

  11. Isolation and characterization of plant growth-promoting rhizobacteria from wheat rhizosphere and their effect on plant growth promotion

    Directory of Open Access Journals (Sweden)

    M. Kaleem eABBASI

    2015-03-01

    Full Text Available AbstractThe present study was conducted to characterize the native plant growth promoting bacteria from wheat rhizosphere and root-endosphere in the Himalayan region of Rawalakot, Azad Jammu and Kashmir (AJK, Pakistan. Nine bacterial isolates were purified, screened in vitro for plant growth promoting (PGP characteristics and evaluated for their beneficial effects on the early growth of wheat (Triticum aestivum L.. Among nine bacterial isolates, seven were able to produce indole-3- acetic acid in tryptophan-supplemented medium; seven were nitrogen fixer, and four were able to solubilize inorganic phosphate in vitro. Four different morphotypes were genotypically identified based on IGS-RFLP fingerprinting and representative of each morphotype was identified by 16S rRNA gene sequencing analysis except Gram positive putative Bacillus sp. Based on 16S rRNA gene sequence analysis, bacterial isolates AJK–3 and AJK-9 showing multiple PGP-traits were identified as Stenotrophomonas spp. while AJK-7 showed equal homologies to Acetobacter pasteurianus and Stenotrophomonas specie. Plant inoculation studies indicated that these PGPR strains provided a significant increase in shoot and root length, and shoot and root biomass. A significant increase in shoot N contents (up to 76% and root N contents (up to 32% was observed over the un-inoculated control. The study indicates the potential of these PGPR for inoculums production or biofertilizers for enhancing growth and nutrient content of wheat and other crops under field conditions. The study is the first report of wheat associated bacterial diversity in the Himalayan region of Rawalakot, AJK.

  12. Functional dissection of the bipartite active site of the class I coenzyme A (CoA-transferase succinyl-CoA:acetate CoA-transferase

    Directory of Open Access Journals (Sweden)

    Jesse Ray Murphy

    2016-05-01

    Full Text Available Coenzyme A (CoA-transferases catalyze the reversible transfer of CoA from acyl-CoA thioesters to free carboxylates. Class I CoA-transferases produce acylglutamyl anhydride intermediates that undergo attack by CoA thiolate on either the internal or external carbonyl carbon atoms, forming distinct tetrahedral intermediates less than 3 Å apart. In this study, crystal structures of succinyl-CoA:acetate CoA-transferase (AarC from Acetobacter aceti are used to examine how the Asn347 carboxamide stabilizes the internal oxyanion intermediate. A structure of the active mutant AarC-N347A bound to CoA revealed both solvent replacement of the missing contact and displacement of the adjacent Glu294, indicating that Asn347 both polarizes and orients the essential glutamate. AarC was crystallized with the nonhydrolyzable acetyl-CoA (AcCoA analogue dethiaacetyl-CoA (1a in an attempt to trap a closed enzyme complex containing a stable analogue of the external oxyanion intermediate. One active site contained an acetylglutamyl anhydride adduct and truncated 1a, an unexpected result hinting at an unprecedented cleavage of the ketone moiety in 1a. Solution studies confirmed that 1a decomposition is accompanied by production of near-stoichiometric acetate, in a process that seems to depend on microbial contamination but not AarC. A crystal structure of AarC bound to the postulated 1a truncation product (2a showed complete closure of one active site per dimer but no acetylglutamyl anhydride, even with acetate added. These findings suggest that an activated acetyl donor forms during 1a decomposition; a working hypothesis involving ketone oxidation is offered. The ability of 2a to induce full active site closure furthermore suggests that it subverts a system used to impede inappropriate active site closure on unacylated CoA.

  13. 低温条件下1,2,4-三氯苯降解菌的筛选及降解特性%Screening and Degrading Characteristics of High Efficiency 1, 2, 4-Trichlorobenzene Degrading Bacteria under Low Temperature Conditions

    Institute of Scientific and Technical Information of China (English)

    黄蓓佳; 张兰英; 王少平

    2008-01-01

    在10℃的低温条件下,从吉林石化化工厂排污管和长春第一汽车制造厂污水处理厂的混合污泥中驯化并分离出10株能以1,2,4-三氯苯(1,2,4-TCB)为唯一碳源的降解菌株,通过筛选得到6株高效1,2,4-TCB降解菌株.以6株菌的混合菌为研究对象,考察其对1,2.4-TCB的降解特性.结果表明,混合菌在以葡萄糖为辅助碳源,硫脲为氮源,pH为7.0,盐度为2.0%,溶液体积100 mL的条件下对1,2,4-TCB的降解效果最佳,且添加辅助碳源对1,2,4-TCB的降解有一定的促进作用.根据菌种的生理生化特征对降解菌进行初步鉴定,结果表明,6株菌分别属于弧菌属(Vibrio sp.),奈瑟氏球菌属(Neisseria sp.),螺菌属(Spirillum sp.),无色细菌属(Achromobacter sp.),醋酸单胞菌属(Acetobacter sp.)和节细菌属(Archrobactersp.).

  14. Screening and fermentation characteristics of acetic acid bacteria with ethanol and high temperature tolerance%高耐受性醋酸菌的筛选及发酵特性研究

    Institute of Scientific and Technical Information of China (English)

    陈洋; 汪超; 高冰; 李冬生; 徐宁; 胡勇

    2015-01-01

    从工业醋醅中分离出5株耐乙醇、耐高温的产醋酸菌株,利用生理生化试验和16S rDNA同源序列分析,初步认定其为巴氏醋杆菌(Acetobacter pasteurianus).通过对其耐乙醇、耐高温发酵特性的研究,发现菌株FY4可耐受体积分数为12%的乙醇和43℃高温,在30℃和体积分数10%乙醇条件下产酸量达到最高,为61.2 g/L.在10L发酵罐试验中,菌株FY4的产酸量始终高于醋酸菌AS1.41,在37℃和体积分数10%乙醇条件下,菌株FY4产酸量达到42.2 g/L,而在此条件下工业菌株AS1.41几乎停止产酸.结果表明菌株FY4具有高耐受性,可产生大量的醋酸,在工业生产中具有潜在应用价值.

  15. Research on the Fermentation Conditions of Liquid-State Vinegar%液态醋酿造发酵条件研究

    Institute of Scientific and Technical Information of China (English)

    吴冬梅

    2014-01-01

    以米粉为原料,经淀粉酶液化、糖化酶糖化和酿醋酵母静置发酵后接入醋酸菌(犃犮犲狋狅犫犪犮狋犲狉狉犪狀-犮犲狀狊)1.41,继续静置发酵产生醋酸。实验探讨了醋酸菌在不同条件下产醋酸的能力,并最终确定在酵母菌接种量为10%,醋酸菌接种量为10%,自然pH(pH 3.4),不需要额外添加乙醇或乙酸的条件下产酸,酸度约为5 g/dL。%Rice flour is used as raw material,after being treated with diastasum,saccharifying enzyme and yeasts,inoculated into hydrolyzed liquid for static fermentation at a certain time,and then acetobacter rancens 1 .41 is inoculated and continuous to ferment for producing acetic acid.The effects of different conditions on acid producing capacity are investigated,and the results show that the acidity could be reaches about 5 g/dL under the conditions that the inoculums of 10% for both yeast and ace-tic acid bacteria at nature pH value (pH 3.4).Furthermore,there's no need to add any alcohol as well as acetic acid during the fermentation process.

  16. 有效微生物菌群对鸡大肠杆菌病防制效果试验%Prevention Effectiveness of Effective Microorganisms in Chicken Escherichia Coli

    Institute of Scientific and Technical Information of China (English)

    张进隆; 何彦春

    2012-01-01

    Effective microorganisms (EM) is a kind of compound microbial preparation, including photosynthetic bacteria, yeast, lactic acid bacteria, actinomycetes, Acetobacter. EM used in livestock and poultry raising can improve feeding environment, decrease disease incidence, increase feed reward and raising benefit. Effect of EM used in chicken Escherichia Coli (E. coli) prevention was conducted in this study. The results showed that EM had evident prevention effect for chicken E. coli, moreover, no drug residue and pollution for this method, therefore it is a kind effective and green environmental protection way and beneficial for the production of nuisance free livestock product.%有效微生物菌群(EM)是一种复合高效微生物制剂,含有光和菌、乳酸菌、酵母菌、放线菌、醋酸杆菌五大类80多种有益微生物。在养殖业上使用EM具有改善饲养环境、降低发病率、提高饲料报酬、增加养殖效益等作用。本研究进行了EM对鸡大肠杆菌病的防制效果试验。试验表明:EM对鸡大肠杆菌病具有显著的防制效果,且这种防制方法不产生药物残留,无污染,是一种有效的绿色环保的防制方法,十分有利于无公害畜产品的生产。

  17. 16S rDNA PCR-RFLP analysis and phylogeny of bacteria isolated from swamp and meadow aeolian soils in the Zoige Plateau, Sichuan, China%若尔盖高原沼泽土和草甸风沙土细菌16S rDNA PCR-RFLP和系统发育分析

    Institute of Scientific and Technical Information of China (English)

    张可; 陈强; 赵珂; 王文跃; 朱雪梅

    2010-01-01

    采用稀释平板法从若尔盖高原沼泽土和草甸风沙土分离获得66株细菌,在16S rDNA PCR-RFLP分析的基础上,测定了22株代表菌株的16S rDNA序列,构建了供试细菌的系统发育关系.16S rDNA PCR-RFLP分析中,在78%相似性水平处,除REG14,REG20,REG22和REG55单独成群外,其余菌株分为8个遗传群,其中,群Ⅰ和群Ⅳ最大,均有15个菌株,其次是群Ⅷ,由11个菌株组成,其余21个菌株分布于5个群内.对22个代表菌株16S rDNA全序列系统发育表明,这些菌株分布于不同的系统发育分支.其中,以芽孢杆菌属(Bacillus)、假单胞菌属(Pseudomonas)和分枝杆菌属(Mycobacterium)为主,其余菌株分布于Lysinibacillus属、中华根瘤菌属(Sinorhizobium)、不动杆菌(Acinetobacter)、固氮菌属(Azotobacter)、红球菌属(Rhodococcus)、微球菌属(Micrococcus)和醋酸杆菌属(Acetobacter)等7个属.

  18. Preparation and characterization of novel wound dressing based on silver nanoparticle-impregnated bacterial cellulose and bacterial cellulose-aloe vera

    International Nuclear Information System (INIS)

    Ideal wound dressings stimulate wound healing, control unpleasant odors, and provide antimicrobial action in wounds. However, most traditional wound dressings such as gauze and biological dressings exhibit exudate leaking which increases the risk of infection and delayed wound healing of tissues. This study aims to develop and characterize a bio-composite of bacterial cellulose and aloe vera having the ideal features of a wound dressing from Acetobacter xylinum-activated culture medium supplemented with various aloe vera concentrations from )-50% (v/v) and the film which exhibits the most uniform results is used for the incorporation of silver nanoparticle as an antibacterial agent. The biopolymer composites of bacterial cellulose and aloe vera were developed by adding 0-50% aloe vera (v/v) in the A. xylinum-activated coconut water medium during biosynthesis in static cultivation for 10 days. The films obtained after drying the membranes were named as bacterial cellulose-aloe vera (BC-A) films. The moisture content of films reached 99% which indicates that the films may be suitable for providing a moist environment to facilitate wound healing fast. With the addition of aloe vera up to 30% (v/v) during BC synthesis, it resulted in a significant improvement in the water absorption capacity of the films showing a WAC ration of 36.46 (r.s.d.= 12.17%, n=3) compared to the unmodified film having a ratio of 9.03 (r.s.d.= 13.95%, n=3). However, the addition of aloe vera at a concentration greater than 30% (v/v) resulted in a decrease in pellicle formation which can be observed from the very weak properties of the films. The BC-A (30%) displayed significantly improved in comparison to the unmodified BC film. Also, it is capable of absorbing high amount of water than its weight and can act as a potential wound dressing which reduces irritation and inflammation. (author)

  19. The impact of yeast starter cultures on the microbial communities and volatile compounds in cocoa fermentation and the resulting sensory attributes of chocolate.

    Science.gov (United States)

    Batista, Nádia Nara; Ramos, Cíntia Lacerda; Dias, Disney Ribeiro; Pinheiro, Ana Carla Marques; Schwan, Rosane Freitas

    2016-02-01

    Theobroma cacao seeds are the main raw material for chocolate production. During their fermentation, a succession of microorganisms are responsible for the physicochemical changes occurring in the pulp and inside the beans. The aim of this study was to investigate the effects of yeast inoculation (Saccharomyces cerevisiae UFLA CA11, Pichia kluivery CCMA0237, and Hanseniaspora uvarum CCMA0236) on the profile of the volatile compounds and microbial communities in cocoa fermentation. The resulting chocolate was also evaluated by temporal dominance of sensations (TDS) analyses. The dominant microorganisms during spontaneous fermentation were S. cerevisiae, H. uvarum, H. guilliermondii, Lactobacillus fermentum, Pediococcus sp., and Acetobacter pasteurianus. Similarly, S. cerevisiae, P. kluyveri, Candida sp., Pediococcus sp., and A. pasteurianus were the predominant microorganisms assessed by Denaturing Gradient Gel Electrophoresis (DGGE) in inoculated fermentation. Sixty-seven volatile compounds were detected and quantified by gas chromatography/mass spectrometry (GC/MS) at the end of fermentation and chocolates. The main group of volatile compound found after the inoculated and spontaneous fermentations was esters (41 and 39 %, respectively). In the chocolates, the main group was acids (73 and 44 % from the inoculated and spontaneous fermentations, respectively). The TDS analyses showed a dominance of bitter and cocoa attributes in both chocolates. However, in the inoculated chocolate, lingering fruity notes were more intense, while the chocolate produced by spontaneous fermentation was more astringent. Thus, the inoculation of yeast influenced the microbial profile, which likely affected the volatile compounds that affect sensory characteristics, resulting in chocolate with dominant bitter, cocoa, and fruity attributes. PMID:27162390

  20. Study on the development of high yielding alcohol resistant strain of Saccharomyces cerevisiae and the Influence of Magnetic field on Saccharomyces cerevisiae Inoculum for the production of Alcohol and Vinegar from apple juice.

    Directory of Open Access Journals (Sweden)

    Rabiul Haque

    2014-12-01

    Full Text Available Natural vinegar is one of the fermented products which has some potentiality with respect to a nutraceutical standpoint. The present study is an optimization of the fermentation conditions for apple juice vinegar production from aple juice wine, this biochemical process being aided by Acetobacter aceti.We have studied on the development of high yielding alcohol resistant strain of Saccharomyces cerevisiae for the production of alcohol. Overflow metabolism is an undesirable characteristic of aerobic cultures of Saccharomyces cerevisiae during biomassdirected processes. It results from elevated apple juice containing sugar consumption rates that cause a high substrate conversion to ethanol and other bi-products, severely affecting cell physiology, bioprocess performance, and biomass yields. Fed-batch culture, where sucrose consumption rates are controlled by the external addition of sugar aiming at its low concentrations in the fermentor, is the classical bioprocessing alternative to prevent sugar fermentation by yeasts. However, fed-batch fermentations present drawbacks that could be overcome by simpler batch cultures at relatively high initial sugar concentrations From the results it is clear that strain T2. which has been exposed to 15% alcohol for 18 hrs is the high yielding strain, as it gives 16% alcohol after distillation. We also find that as the exposure is increased, that is, with increasing exposure to 20% alcohol for 5 hrs, 18 hrs, and 20 hrs, the production of alcohol decreases. Saccharomyces cerevisiae yeast cells strain T2. which has been exposed to 15% alcohol for 18 hrs were exposed to a homogenous static magnetic field of 125 mT for periods of 24, 48 or 72 hours and then used as inoculum for the alcoholic fermentation. The exposure to the magnetic field improved the fermentation process kinetics. Biomass and ethanol yields of fermentations inoculated with treated inoculum were higher than those in the control fermentation, which

  1. The gut bacterial communities associated with lab-raised and field-collected ants of Camponotus fragilis (Formicidae: Formicinae).

    Science.gov (United States)

    He, Hong; Wei, Cong; Wheeler, Diana E

    2014-09-01

    Camponotus is the second largest ant genus and known to harbor the primary endosymbiotic bacteria of the genus Blochmannia. However, little is known about the effect of diet and environment changes on the gut bacterial communities of these ants. We investigated the intestinal bacterial communities in the lab-raised and field-collected ants of Camponotus fragilis which is found in the southwestern United States and northern reaches of Mexico. We determined the difference of gut bacterial composition and distribution among the crop, midgut, and hindgut of the two types of colonies. Number of bacterial species varied with the methods of detection and the source of the ants. Lab-raised ants yielded 12 and 11 species using classical microbial culture methods and small-subunit rRNA genes (16S rRNAs) polymerase chain reaction-restriction fragment-length polymorphism analysis, respectively. Field-collected ants yielded just 4 and 1-3 species using the same methods. Most gut bacterial species from the lab-raised ants were unevenly distributed among the crop, midgut, and hindgut, and each section had its own dominant bacterial species. Acetobacter was the prominent bacteria group in crop, accounting for about 55 % of the crop clone library. Blochmannia was the dominant species in midgut, nearly reaching 90 % of the midgut clone library. Pseudomonas aeruginosa dominated the hindgut, accounting for over 98 % of the hindgut clone library. P. aeruginosa was the only species common to all three sections. A comparison between lab-raised and field-collected ants, and comparison with other species, shows that gut bacterial communities vary with local environment and diet. The bacterial species identified here were most likely commensals with little effect on their hosts or mild pathogens deleterious to colony health. PMID:24748441

  2. Adaptive mutation related to cellulose producibility in Komagataeibacter medellinensis (Gluconacetobacter xylinus) NBRC 3288.

    Science.gov (United States)

    Matsutani, Minenosuke; Ito, Kohei; Azuma, Yoshinao; Ogino, Hidetaka; Shirai, Mutsunori; Yakushi, Toshiharu; Matsushita, Kazunobu

    2015-09-01

    Gluconacetobacter xylinus (formerly Acetobacter xylinum and presently Komagataeibacter medellinensis) is known to produce cellulose as a stable pellicle. However, it is also well known to lose this ability very easily. We investigated the on and off mechanisms of cellulose producibility in two independent cellulose-producing strains, R1 and R2. Both these strains were isolated through a repetitive static culture of a non-cellulose-producing K. medellinensis NBRC 3288 parental strain. Two cellulose synthase operons, types I and II, of this strain are truncated by the frameshift mutation in the bcsBI gene and transposon insertion in the bcsCII gene, respectively. The draft genome sequencing of R1 and R2 strains revealed that in both strains the bcsBI gene was restored by deletion of a nucleotide in its C-rich region. This result suggests that the mutations in the bcsBI gene are responsible for the on and off mechanism of cellulose producibility. When we looked at the genomic DNA sequences of other Komagataeibacter species, several non-cellulose-producing strains were found to contain similar defects in the type I and/or type II cellulose synthase operons. Furthermore, the phylogenetic relationship among cellulose synthase genes conserved in other bacterial species was analyzed. We observed that the cellulose genes in the Komagataeibacter shared sequence similarities with the γ-proteobacterial species but not with the α-proteobacteria and that the type I and type II operons could be diverged from a same ancestor in Komagataeibacter. PMID:25913006

  3. Occurrence of Cellulose-Producing Gluconacetobacter spp. in Fruit Samples and Kombucha Tea, and Production of the Biopolymer.

    Science.gov (United States)

    Neera; Ramana, Karna Venkata; Batra, Harsh Vardhan

    2015-06-01

    Cellulose producing bacteria were isolated from fruit samples and kombucha tea (a fermented beverage) using CuSO4 solution in modified Watanabe and Yamanaka medium to inhibit yeasts and molds. Six bacterial strains showing cellulose production were isolated and identified by 16S rRNA gene sequencing as Gluconacetobacter xylinus strain DFBT, Ga. xylinus strain dfr-1, Gluconobacter oxydans strain dfr-2, G. oxydans strain dfr-3, Acetobacter orientalis strain dfr-4, and Gluconacetobacter intermedius strain dfr-5. All the cellulose-producing bacteria were checked for the cellulose yield. A potent cellulose-producing bacterium, i.e., Ga. xylinus strain DFBT based on yield (cellulose yield 5.6 g/L) was selected for further studies. Cellulose was also produced in non- conventional media such as pineapple juice medium and hydrolysed corn starch medium. A very high yield of 9.1 g/L cellulose was obtained in pineapple juice medium. Fourier transform infrared spectrometer (FT-IR) analysis of the bacterial cellulose showed the characteristic peaks. Soft cellulose with a very high water holding capacity was produced using limited aeration. Scanning electron microscopy (SEM) was used to analyze the surface characteristics of normal bacterial cellulose and soft cellulose. The structural analysis of the polymer was performed using (13)C solid-state nuclear magnetic resonance (NMR). More interfibrillar space was observed in the case of soft cellulose as compared to normal cellulose. This soft cellulose can find potential applications in the food industry as it can be swallowed easily without chewing. PMID:25926011

  4. Change in the plasmid copy number in acetic acid bacteria in response to growth phase and acetic acid concentration.

    Science.gov (United States)

    Akasaka, Naoki; Astuti, Wiwik; Ishii, Yuri; Hidese, Ryota; Sakoda, Hisao; Fujiwara, Shinsuke

    2015-06-01

    Plasmids pGE1 (2.5 kb), pGE2 (7.2 kb), and pGE3 (5.5 kb) were isolated from Gluconacetobacter europaeus KGMA0119, and sequence analyses revealed they harbored 3, 8, and 4 genes, respectively. Plasmid copy numbers (PCNs) were determined by real-time quantitative PCR at different stages of bacterial growth. When KGMA0119 was cultured in medium containing 0.4% ethanol and 0.5% acetic acid, PCN of pGE1 increased from 7 copies/genome in the logarithmic phase to a maximum of 12 copies/genome at the beginning of the stationary phase, before decreasing to 4 copies/genome in the late stationary phase. PCNs for pGE2 and pGE3 were maintained at 1-3 copies/genome during all phases of growth. Under a higher concentration of ethanol (3.2%) the PCN for pGE1 was slightly lower in all the growth stages, and those of pGE2 and pGE3 were unchanged. In the presence of 1.0% acetic acid, PCNs were higher for pGE1 (10 copies/genome) and pGE3 (6 copies/genome) during the logarithmic phase. Numbers for pGE2 did not change, indicating that pGE1 and pGE3 increase their PCNs in response to acetic acid. Plasmids pBE2 and pBE3 were constructed by ligating linearized pGE2 and pGE3 into pBR322. Both plasmids were replicable in Escherichia coli, Acetobacter pasteurianus and G. europaeus, highlighting their suitability as vectors for acetic acid bacteria. PMID:25575969

  5. Phylogenetic analysis of a spontaneous cocoa bean fermentation metagenome reveals new insights into its bacterial and fungal community diversity.

    Directory of Open Access Journals (Sweden)

    Koen Illeghems

    Full Text Available This is the first report on the phylogenetic analysis of the community diversity of a single spontaneous cocoa bean box fermentation sample through a metagenomic approach involving 454 pyrosequencing. Several sequence-based and composition-based taxonomic profiling tools were used and evaluated to avoid software-dependent results and their outcome was validated by comparison with previously obtained culture-dependent and culture-independent data. Overall, this approach revealed a wider bacterial (mainly γ-Proteobacteria and fungal diversity than previously found. Further, the use of a combination of different classification methods, in a software-independent way, helped to understand the actual composition of the microbial ecosystem under study. In addition, bacteriophage-related sequences were found. The bacterial diversity depended partially on the methods used, as composition-based methods predicted a wider diversity than sequence-based methods, and as classification methods based solely on phylogenetic marker genes predicted a more restricted diversity compared with methods that took all reads into account. The metagenomic sequencing analysis identified Hanseniaspora uvarum, Hanseniaspora opuntiae, Saccharomyces cerevisiae, Lactobacillus fermentum, and Acetobacter pasteurianus as the prevailing species. Also, the presence of occasional members of the cocoa bean fermentation process was revealed (such as Erwinia tasmaniensis, Lactobacillus brevis, Lactobacillus casei, Lactobacillus rhamnosus, Lactococcus lactis, Leuconostoc mesenteroides, and Oenococcus oeni. Furthermore, the sequence reads associated with viral communities were of a restricted diversity, dominated by Myoviridae and Siphoviridae, and reflecting Lactobacillus as the dominant host. To conclude, an accurate overview of all members of a cocoa bean fermentation process sample was revealed, indicating the superiority of metagenomic sequencing over previously used techniques.

  6. Prokaryotic squalene-hopene cyclases can be converted to citronellal cyclases by single amino acid exchange.

    Science.gov (United States)

    Siedenburg, Gabriele; Breuer, Michael; Jendrossek, Dieter

    2013-02-01

    Squalene-hopene cyclases (SHCs) are prokaryotic enzymes that catalyse the cyclisation of the linear precursor squalene to pentacyclic hopene. Recently, we discovered that a SHC cloned from Zymomonas mobilis (ZMO-1548 gene product) has the unique property to cyclise the monoterpenoid citronellal to isopulegol. In this study, we performed saturation mutagenesis of three amino acids of the catalytic centre of ZMO-1548 (F428, F486 and W555), which had been previously identified to interact with enzyme-bound substrate. Replacement of F428 by tyrosine increased hopene formation from squalene, but isopulegol-forming activity was strongly reduced or abolished in all muteins of position 428. W555 was essential for hopene formation; however, three muteins (W555Y, W428F or W555T) revealed enhanced cyclisation efficiency with citronellal. The residue at position 486 turned out to be the most important for isopulegol-forming activity. While the presence of phenylalanine or tyrosine favoured cyclisation activity with squalene, several small and/or hydrophobic residues such as cysteine, alanine or isoleucine and others reduced activity with squalene but greatly enhanced isopulegol formation from citronellal. Replacement of the conserved aromatic residue corresponding to F486 to cysteine in other SHCs cloned from Z. mobilis (ZMO-0872), Alicyclobacillus acidocaldarius (SHC(Aac)), Acetobacter pasteurianus (SHC(Apa)), Streptomyces coelicolor (SHC(Sco)) and Bradyrhizobium japonicum (SHC(Bja)) resulted in more or less strong isopulegol-forming activities from citronellal. In conclusion, many SHCs can be converted to citronellal cyclases by mutagenesis of the active centre thus broadening the applicability of this interesting class of biocatalyst. PMID:22526778

  7. 醋酸菌中CRISPR位点的比较基因组学与进化分析%Comparative genomics and evolutionary analysis of CRISPR loci in acetic acid bacteria

    Institute of Scientific and Technical Information of China (English)

    夏凯; 梁新乐; 李余动

    2015-01-01

    CRISPR (Clustered regularly interspaced short palindromic repeats)是近几年发现的一种广泛存在于细菌和古菌中,能够应对外源DNA干扰(噬菌体、病毒、质粒等),并提供免疫机制的重复序列结构。CRISPR系统通常由同向重复序列、前导序列、间隔序列和CRISPR相关蛋白组成。本研究以醋酸发酵中常见3个属醋杆菌属(Acetobacter)、葡糖醋杆菌属(Gluconacetobacter)和葡糖杆菌属(Gluconobacter)的48个菌株为研究对象,通过其基因组上CRISPR相关基因序列的生物信息学分析,探索CRISPR位点在醋酸菌中的多态性及其进化模式。结果表明48株醋酸菌中有32株存在CRISPR结构,大部分CRISPR-Cas结构属于type I-E和type I-C类型。除了葡糖杆菌属外,葡糖醋杆菌属和醋杆菌属中的部分菌株含有 II 类的 CRISPR-Cas 系统结构(CRISPR-Cas9)。来自不同属菌株的CRISPR结构中重复序列具有较强的保守性,而且部分菌株CRISPR结构中的前导序列具有保守的motif (与基因的转录调控有关)及启动子序列。进化树分析表明cas1适合用于醋酸菌株的分类,而不同菌株间 cas1基因的进化与重复序列的保守性相关,预示它们可能受相似的功能选择压力。此外,间隔序列的数量与噬菌体数量及插入序列(Insertion sequence, IS)数量有正相关的趋势,说明醋酸菌在进化过程中可能正不断受新的外源DNA入侵。醋酸菌中CRISPR结构位点的分析,为进一步研究不同醋酸菌株对醋酸胁迫耐受性差异及其基因组稳定性的分子机制奠定了基础。%The clustered regularly interspaced short palindromic repeat (CRISPR) is a widespread adaptive immun-ity system that exists in most archaea and many bacteria against foreign DNA, such as phages, viruses and plasmids. In general, CRISPR system consists of direct repeat, leader, spacer and CRISPR-associated sequences. Acetic ac-id bacteria (AAB) play an

  8. 不同含水量和菌剂对紫花苜蓿裹包青贮质量的影响%Effects of Moisture Contents and Inoculants on Quality of Wrapped Alfalfa Silage

    Institute of Scientific and Technical Information of China (English)

    王星凌; 朱荣生; 赵红波; 胡明; 黄保华

    2015-01-01

    H and NH3 -N values,and extremely low lactic acid bacteria and lactic acid.The butyric acid and propionic acid were also observed (P <0.05,P <0.01 ).The wrapped alfalfa silage with 45% moisture had more yeast and mold colonies,and lower acetic acid content (P <0.01 ).That with 70% or 55% moisture achieved the best estimates (P <0.05,P <0.01 ).With the moisture contents of wrapped alfalfa silage decreasing from 70% to 45%,supplementing A.oryzae lowered pH value,inhibited yeast and mold colonies and promoted the production of lactic acid(P <0.05,P <0.01 );while supplementing L.plantarum reduced NH3 -N and ace-tobacter colonies,and lowered acetic acid content (P <0.05).The moisture and inoculants of wrapped alfalfa silages had interaction effects on lactic acid bacteria and acetobacter colonies,which resulted in the changes of lactic acid and acetic acid production (P <0.05).It is concluded that the moisture content was more impor-tant to the wrapped alfalfa silage quality than supplementing inoculants,and that with 70% or 55% moisture contents had the best estimates.Supplementing A.oryzae promoted lactic acid bacteria fermentation to produce more lactic acid,and supplementing L.plantarum lowered NH3 -N value,and reduced acetobacter colonies and acetic acid production with low moisture contents.

  9. Study on Technology of Composite Fruit Vinegar of Apple and Pomelo%苹果柚子复合果醋的研制

    Institute of Scientific and Technical Information of China (English)

    王乃馨; 陈尚龙; 李超; 吕可愉; 钱浩

    2016-01-01

    以苹果和柚子为原料,选用安琪酵母、醋酸菌作为发酵菌种进行发酵酿造苹果柚子复合果醋,对原汁配比、酒精发酵、醋酸发酵及果醋调配等工艺进行研究。实验结果表明:苹果汁和柚子汁最佳混合体积比为1∶1;酒精发酵的最佳工艺参数为初始糖度16%、初始 pH 值4.4、接种量8%、发酵温度32℃和发酵时间6天;醋酸发酵的最佳工艺参数为初始酒精含量8%,初始 pH 值5.2,接种量9%,发酵温度30℃和发酵时间6天;调配的最佳配方为原醋添加量30 mL、苹果汁添加量20 mL、柚子汁添加量20 mL和白砂糖添加量3 g/dL。%Compound fruit vinegar of apple and pomelo is produced by liquid fermentation using Anqi yeast and acetobacter as strains.The ratio of materials,alcohol and acetic acid fermentation and fruit vinegar blending process are studied.The results show that the best ratio of apple juice and pomelo juice is 1∶1;the optimal technological parameters of alcohol fermentation are initial sugar content of 16%,initial pH value of 4.4,inoculation amount of 8%,fermentation temperature of 32 ℃ and fermentation time of 6 days;the optimal technological parameters of acetic acid fermentation are initial alcohol content of 8%,initial pH value of 5.2,inoculation amount of 9%,fermentation temperature of 30 ℃ and fermentation time of 6 days;the best formula is vinegar amount of 30 mL,apple juice amount of 20 mL,pomelo juice amount of 20 mL,sugar amount of 3 g/dL.

  10. Genetic analysis on 16S rDNA of brucella%布鲁菌16S rDNA基因遗传分析

    Institute of Scientific and Technical Information of China (English)

    李克诚; 周邦谣; 夏菲

    2013-01-01

    目的 通过分析临床分离的布鲁菌、其他盐杆菌科细菌以及临床常见致病菌的16S rDNA基因片段的差异并构建16S rDNA系统发育树,为进一步研究布鲁菌打下基础.方法 PCR扩增临床分离株的16SrDNA并测序;从EMBL下载常见盐杆菌科细菌和临床上常见致病菌的16S rDNA序列.利用CLUSTALX和MEGA程序进行16S rDNA比对并构建系统发育树.结果 成功扩增了临床分离菌株的16S rDNA,得到测序结果,比对临床分离菌株和相关菌株后,发现了特异序列5’-ATCCCGGTCGCGGTTAGTGG-3';系统发育树表明不同种的布鲁菌间的距离非常接近;布鲁菌和醋菌属的进化距离较近,但是和其他的盐杆菌的进化距离较远.结论 在布鲁菌16S rDNA中存在特异序列5'-ATCCCGGTCGCGGTTAGTGG-3’,有可能作为探针来快速检测布鲁氏菌.%Objective To analyze and to compare the genetic characteristics of 16S rDNA gene of Brucella with other halobacteriaceae and pathogenic bacteria, and to construct phylogenetic tree to find the specific sequence. Methods 16s rDNA of Brucella isolated from clinical sample was amplified and sequenced, which was then compared with sequences of halobacteriaceae and other pathogenic bacteria downloaded from EM-BL. CLUSTALA and MEGA software were used for the comparison of the sequences and building of the phylogenetic tree. Results 16s rDNA was successfully amplified and sequenced. Meanwhile, a specific sequence of 5' -ATCCCGGTCGCGGTTAGTGG-3' was identified. Phylogenetic tree showed that the distance was very close among different species of Brucella and was also closer to acetobacter sp. . but was farther to other halobacteriaceae. Conclusions A specific sequence is present in 16S rDNA of brucella which could be used as a probe to detect Brucella.

  11. Study of fermentation process in yacon-passion fruit mixed vinegar%雪莲果西番莲复合果醋发酵工艺的研究

    Institute of Scientific and Technical Information of China (English)

    潘嫣丽; 黄友琴; 黄夏; 姜元欣; 梁荣慧; 朱其斌; 朱才

    2012-01-01

    Yacon and passion fruit were selected to make fermented yacon-passion fruit mixed vinegar by dry activate wine yeast and acetobacter in liquid fermentation. The ethanol fermentation, acetic acid fermentation and fruit vinegar purification conditions were studied to determine the best process. Results showed that the best ethanol fermentation condition is initial sugar content 14%, yeast inoculum 0.012% and fermentation temperature 28℃;The best acetic acid fermentation condition is fermentation temperature 34℃, ethanol content 8%vol, fermentation period 4d, vaccination content 4%. Diatomite content 0.06% yield a good purification rate and led to a transmittance rate 90.5%. Final product of yacon-passion fruit mixed vinegar is purified with a strong vinegar smell. It has all the delightful characteristic of both yacon and passion fruit.%以雪莲果和西番莲为原料,选用葡萄酒用活性干酵母、醋酸杆菌作为发酵菌种进行液体发酵酿造雪莲果西番莲复合果醋,对酒精发酵、醋酸发酵及果醋澄清等工艺进行研究,确定最佳加工工艺参数.结果表明:酒精发酵的最佳条件为:初始糖度14%,酵母菌接种量0.012%,发酵温度28℃;醋酸发酵的最佳条件为:发酵温度34℃、酒精度8%vol、发酵时间4d、接种量4%;硅藻土用量为0.06%,澄清效果较佳,透光率可达90.5%.酿制出来的雪莲果西番莲复合果醋澄清透亮,醋味浓郁,同时具有雪莲果和西番莲的特殊清香味.

  12. 猕猴桃果醋发酵工艺优化及质量分析%Process Optimization for Kiwi Fruit Vinegar Fermentation and Quality Analysis

    Institute of Scientific and Technical Information of China (English)

    李加兴; 孙金玉; 陈双平; 黄诚; 严友兵; 王小勇

    2011-01-01

    The fermentation of kiwi fruit vinegar from kiwi fruit pulp was optimized by one-factor-at-a-time combined with orthogonal array design method and physicochemical,sensory,hygiene and microbiological properties of the fruit vinegar were analyzed.The optimal process conditions for fermenting kiwi fruit pulp into kiwi fruit vinegar were 2.5 h treatment at 45 ℃ by 0.04 g/L pectinase complex,alcoholic fermentation with active dry yeast at an inoculation amount of 0.05 g/L until an alcohol degree of 6%(V/V),and then5-day acetic acid fermentation with Acetobacter at an inoculation amount of 0.7‰(V/V).The fruit vinegar obtained under these conditions showed an acetic acid content of 6.17 g/100 mL,and all other quality indicators were in accordance with the requirements of relevant national standards.%以猕猴桃果浆为原料,对果醋的发酵工艺进行优化并对其产品质量进行分析。通过单因素试验探讨复合果胶酶添加量、活性干酵母接种量、发酵醪酒度、醋酸杆菌接种量、醋酸发酵温度与时间对猕猴桃果醋发酵工艺的影响,通过正交试验得出最佳发酵工艺条件,并采用行业标准分析方法对成品的理化、卫生与微生物指标进行检测。结果表明:猕猴桃果浆在添加0.04g/L复合果胶酶并保温45℃处理2.5h后,进行果醋发酵的最佳工艺条件为活性干酵母接种量0.05g/L,发酵醪酒度达6%(V/V)时接入0.07‰(V/V)醋酸杆菌,于30℃发酵5d;在此条件下,成品中的乙酸含量可达6.17g/100mL,其他各项指标均符合相关国家标准的要求。

  13. The microbial ecology of wine grape berries.

    Science.gov (United States)

    Barata, A; Malfeito-Ferreira, M; Loureiro, V

    2012-02-15

    Grapes have a complex microbial ecology including filamentous fungi, yeasts and bacteria with different physiological characteristics and effects upon wine production. Some species are only found in grapes, such as parasitic fungi and environmental bacteria, while others have the ability to survive and grow in wines, constituting the wine microbial consortium. This consortium covers yeast species, lactic acid bacteria and acetic acid bacteria. The proportion of these microorganisms depends on the grape ripening stage and on the availability of nutrients. Grape berries are susceptible to fungal parasites until véraison after which the microbiota of truly intact berries is similar to that of plant leaves, which is dominated by basidiomycetous yeasts (e.g. Cryptococcus spp., Rhodotorula spp. Sporobolomyces spp.) and the yeast-like fungus Aureobasidium pullulans. The cuticle of visually intact berries may bear microfissures and softens with ripening, increasing nutrient availability and explaining the possible dominance by the oxidative or weakly fermentative ascomycetous populations (e.g. Candida spp., Hanseniaspora spp., Metschnikowia spp., Pichia spp.) approaching harvest time. When grape skin is clearly damaged, the availability of high sugar concentrations on the berry surface favours the increase of ascomycetes with higher fermentative activity like Pichia spp. and Zygoascus hellenicus, including dangerous wine spoilage yeasts (e.g. Zygosaccharomyces spp., Torulaspora spp.), and of acetic acid bacteria (e.g. Gluconobacter spp., Acetobacter spp.). The sugar fermenting species Saccharomyces cerevisiae is rarely found on unblemished berries, being favoured by grape damage. Lactic acid bacteria are minor partners of grape microbiota and while being the typical agent of malolactic fermentation, Oenococcus oeni has been seldom isolated from grapes in the vineyard. Environmental ubiquitous bacteria of the genus Enterobacter spp., Enterococcus spp., Bacillus spp

  14. Evaluation of health aspects of kojic acid in food.

    Science.gov (United States)

    Burdock, G A; Soni, M G; Carabin, I G

    2001-02-01

    Kojic acid is a fungal metabolite commonly produced by many species of Aspergillus, Acetobacter, and Penicillium. The Aspergillus flavus group has traditionally been used in the production of a number of foods, including miso (soybean paste), shoyu (soy sauce), and sake. Kojic acid is widely used as a food additive for preventing enzymatic browning, and in cosmetic preparations as a skin-lightening or bleaching agent. Because kojic acid is often produced during the fermentation of historically used dietary staples, it has a long history of consumption. Various types of compounds, such as glucose, sucrose, acetate, ethanol, arabinose, and xylose, have been used as carbon sources for kojic acid production. Different Aspergillus species are known to produce variable amounts of kojic acid. The mechanism of action of kojic acid is well defined and it has been shown to act as a competitive and reversible inhibitor of animal and plant polyphenol oxidases, xanthine oxidase, and D- and some L-amino acid oxidases. The structure of kojic acid indicates a relatively simple route of metabolism much like dietary hexoses. Acute or subchronic toxicity resulting from an oral dose has not been reported, but convulsions may occur if kojic acid is injected. Results of mutagenicity studies are mixed, but in the in vivo mammalian dominant lethal assay, kojic acid was proven negative. Continuous administration of high doses of kojic acid in mice resulted in induction of thyroid adenomas in both sexes. Kojic acid reversibly affects thyroid function primarily by inhibiting iodine uptake, leading to decreases in T3 and T4 and increase in TSH. Increased TSH from pituitary gland in turn stimulates thyroid hyperplasia. Several lines of evidence indicate that the proliferative effects of kojic acid on thyroid are not related to a genotoxic pathway. The risk of functional inhibition of iodine uptake and its metabolism (organification) and thyroid tumor induction by kojic acid in humans appears

  15. Analysis of bacterial community during the fermentation of pulque, a traditional Mexican alcoholic beverage, using a polyphasic approach.

    Science.gov (United States)

    Escalante, Adelfo; Giles-Gómez, Martha; Hernández, Georgina; Córdova-Aguilar, María Soledad; López-Munguía, Agustín; Gosset, Guillermo; Bolívar, Francisco

    2008-05-31

    In this study, the characterization of the bacterial community present during the fermentation of pulque, a traditional Mexican alcoholic beverage from maguey (Agave), was determined for the first time by a polyphasic approach in which both culture and non-culture dependent methods were utilized. The work included the isolation of lactic acid bacteria (LAB), aerobic mesophiles, and 16S rDNA clone libraries from total DNA extracted from the maguey sap (aguamiel) used as substrate, after inoculation with a sample of previously produced pulque and followed by 6-h fermentation. Microbiological diversity results were correlated with fermentation process parameters such as sucrose, glucose, fructose and fermentation product concentrations. In addition, medium rheological behavior analysis and scanning electron microscopy in aguamiel and during pulque fermentation were also performed. Our results showed that both culture and non-culture dependent approaches allowed the detection of several new and previously reported species within the alpha-, gamma-Proteobacteria and Firmicutes. Bacteria diversity in aguamiel was composed by the heterofermentative Leuconostoc citreum, L. mesenteroides, L. kimchi, the gamma-Proteobacteria Erwinia rhapontici, Enterobacter spp. and Acinetobacter radioresistens. Inoculation with previously fermented pulque incorporated to the system microbiota, homofermentative lactobacilli related to Lactobacillus acidophilus, several alpha-Proteobacteria such as Zymomonas mobilis and Acetobacter malorum, other gamma-Proteobacteria and an important amount of yeasts, creating a starting metabolic diversity composed by homofermentative and heterofermentative LAB, acetic and ethanol producing microorganisms. At the end of the fermentation process, the bacterial diversity was mainly composed by the homofermentative Lactobacillus acidophilus, the heterofermentative L. mesenteroides, Lactococcus lactis subsp. lactis and the alpha-Proteobacteria A. malorum. After

  16. BIO-ORGANIC CHEMISTRY QUARTERLY REPORT. December 1961, January and February 1962

    Energy Technology Data Exchange (ETDEWEB)

    Various,

    1962-04-03

    Progress is reported in investigations on the polymerization of formaldehyde, ultraviolet irradiation of aqueous HC/sup 14/N, radiation chemistry of nucleic acid constituents, oxidation of free sugars and aldonic acid derivatives by Acetobacter suboxydans, preparation and isolation of C/sup 14/O/ sub 2/~ enzyme, metabolism of C/sup 14/-ribulose diphosphate by Nitrobacter agilis, C/sup 14/O/sub 2/ metabolism of Hordeum valgare seedlings during the development of the photosynthetic apparatus, location and chemical characterization of RNA in the chloroplasts of Spinacea oleracea, inhibition of dark bleaching by stroma extracts and by inert gases, ESR studies on chromatophores from Rhodospirillium rubrum and on quantasomes from spinach chloroplasts, and phthalocyanine manganese and etioporphyrin manganese complexes. (J.R.D.) It has been known for a hundred years that formaldehyde polymerizes to carbohydrate substances in alkaline media. Although the reaction has long attracted much attention, only recently has a detailed qualitative analysis of the products been carried out by chromatographic methods. We have started to re-examine this reaction by combining chromatography with radioactive tracer techniques in the hope of refining the quantitative aspects of the analysis. Our particular interest has been to develop methods for determining the relative proportions of ribose and ribulose in the mixtures of sugars formed in basic media, as well as under other polymerizing conditions. The finding of large amounts of these sugars might help to explain the occurrence of ribose as the only basic sugar in the fundamental replicating molecules--the nucleic acids. Formaldehyde is thought to have been present in the primitive reducing atmosphere which existed before life first appeared. The ribonucleic acids must have appeared in the constitution of reproducing systems at a very early stage in the development of living organisms. In this study, the polymerizations of formaldehyde

  17. Otimização da produção de nata (celulose bacteriana por fermentação em superfície

    Directory of Open Access Journals (Sweden)

    DANESI Eliane Dalva Godoy

    1998-01-01

    Full Text Available A nata de coco, alimento glicídico obtido por fermentação em superfície promovida por Acetobacter xylinum, é bastante difundida em alguns países asiáticos, principalmente nas Filipinas. Como meio de cultivo são utilizadas a água ou o leite de coco, produtos de baixo valor econômico e resíduos de processamento da fruta; há indicativos na literatura, entretanto, de que outros resíduos agro-industriais como soro de leite ou mesmo suco de frutas podem ser utilizados. A fim de avaliar a produção de nata para posteriores estudos visando o uso de meios alternativos, foi utilizado um meio de composição definida com o qual foi possível definir as condições de pH, de inóculo e de incubação, assim como observar a influência de açúcares e de ácidos no processo. Foram delineados experimentos usando-se ácido acético e glucose como variáveis de entrada visando a otimização do processo. As condições de fermentação incluíram correção do pH para 4, adição de 10% (v/v de inóculo ao meio e incubação a 28°C por 10 dias. As condições encontradas como ótimas em relação às concentrações iniciais dos nutrientes considerados foram 0,65 moles/l de ácido acético e 67,4 g/l de glucose, com o que se produz 7,107 g de nata por 250 ml de meio .

  18. BIODIVERSITE MICROBIENNE ET PARAMETRES PHYSICOCHIMIQUES DE QUELQUES VINS DE RONIER (BORASSUS AKEASSII PRODUITS TRADITIONNELLEMENT AU BURKINA FASO

    Directory of Open Access Journals (Sweden)

    N. BARRO

    2011-10-01

    Full Text Available La présente étude traite de la biodiversité microbienne et des paramètres physico-chimiques de quelques vins de rônier produits traditionnellement au Burkina Faso. Elle a consisté à la détermination des paramètres physico-chimiques et microbiologiques du vin de rônier issu de la fermentation spontanée de la sève de rônier.L’étude de la composition physico-chimique et des aspects microbiologiques a été réalisée à l’aide des méthodes standards de microbiologie et de physico-chimie. Douze échantillons de sève de rônier fermentée naturellement ont été collectés dans la région de Bobo Dioulasso où ce vin est abondamment produit.Le pH, l’acidité totale, la teneur en sucres totaux et en alcool variaient entre 3,6 et 4,5 ; 0,1 et 1,28 % (m/v ; 0,58 et 8,72 % (m/v ; 4,08 et 7,25 % (v/v respectivement. La flore mésophile totale était entre 1,4.108 et 2,5.108UFC et la flore de levures entre 3,4 106 et 2,85 107UFC par millilitre de vin.Les coliformes totaux étaient présents dans 25 % des échantillons (BFH1, BFH5 et BFH10 à un nombre de l’ordre de 1,28.106 à 4,6.106UFC/ml témoignant une qualité hygiénique pauvre. Lactobacillus, Bacillus, et Acetobacter thermo-tolérants et alcoolo-tolérants impliqués dans le processus de fermentation spontanée de la sève de rônier ont été également isolés et identifiés dans les échantillons BFH1, BFH9 et BFH12.La connaissance des paramètres physico-chimiques et microbiologiques de la sève fermentée du rônier est nécessaire non seulement pour la valorisation de cette boisson locale et traditionnelle mais aussi pour l’exploitation de la biodiversité microbienne.

  19. Enhanced production of bacterial cellulose by using a biofilm reactor and its material property analysis

    Directory of Open Access Journals (Sweden)

    Demirci Ali

    2009-07-01

    Full Text Available Abstract Bacterial cellulose has been used in the food industry for applications such as low-calorie desserts, salads, and fabricated foods. It has also been used in the paper manufacturing industry to enhance paper strength, the electronics industry in acoustic diaphragms for audio speakers, the pharmaceutical industry as filtration membranes, and in the medical field as wound dressing and artificial skin material. In this study, different types of plastic composite support (PCS were implemented separately within a fermentation medium in order to enhance bacterial cellulose (BC production by Acetobacter xylinum. The optimal composition of nutritious compounds in PCS was chosen based on the amount of BC produced. The selected PCS was implemented within a bioreactor to examine the effects on BC production in a batch fermentation. The produced BC was analyzed using X-ray diffraction (XRD, field emission scanning electron microscopy (FESEM, thermogravimetric analysis (TGA, and dynamic mechanical analysis (DMA. Among thirteen types of PCS, the type SFYR+ was selected as solid support for BC production by A. xylinum in a batch biofilm reactor due to its high nitrogen content, moderate nitrogen leaching rate, and sufficient biomass attached on PCS. The PCS biofilm reactor yielded BC production (7.05 g/L that was 2.5-fold greater than the control (2.82 g/L. The XRD results indicated that the PCS-grown BC exhibited higher crystallinity (93% and similar crystal size (5.2 nm to the control. FESEM results showed the attachment of A. xylinum on PCS, producing an interweaving BC product. TGA results demonstrated that PCS-grown BC had about 95% water retention ability, which was lower than BC produced within suspended-cell reactor. PCS-grown BC also exhibited higher Tmax compared to the control. Finally, DMA results showed that BC from the PCS biofilm reactor increased its mechanical property values, i.e., stress at break and Young's modulus when compared to

  20. Nanoskin: uso para reposição de volume na cavidade anoftálmica

    Directory of Open Access Journals (Sweden)

    Natalia Mussi

    2016-06-01

    Full Text Available RESUMO Objetivo: Avaliar a biocompatibilidade da Nanoskin para reposição de volume em cavidades enucleadas ou evisceradas de coelhos. Métodos: Estudo experimental, utilizando implantes de Nanoskin (Innovatecs®, São Carlos, Brasil, celulose bacteriana produzida pela bactéria Acetobacter xylinum tendo como substrato o chá-verde. Implantes de 10mm de diâmetro/5mm de espessura foram colocados em cavidades enucleadas (G1 ou evisceradas (G2 de 21 coelhos, avaliados clinicamente todos os dias, sacrificados aos 7, 30 e 90 dias após a cirurgia. O material foi removido e preparado para exame de microscopia óptica. Resultados: Sinais flogísticos discretos no pósoperatório imediato, não tendo sido evidenciados sinais infecciosos ou extrusão de nenhum implante. Houve aparente redução do volume ao longo do período experimental. Histologicamente ambos os grupos foram muito semelhantes, apresentando aos 7 dias células inflamatórias (predominantemente monócitos e neutrófilos, rede de fibrina e hemácias. A Nanoskin apresentava-se como pequenas esferas, de cor rósea, com pequenos espaços entre elas, permeados por escassas células inflamatórias. As células inflamatórias se modificaram ao longo de período experimental, sendo possível observar aos 30 dias células gigantes multinucleadas e fibroblastos maduros permeando o implante. Aos 90 dias, a estrutura do implante apresentava-se desorganizada, amorfa, com restos necróticos e com áreas ovoides, revestidas por fina membrana rósea, que pareciam se agrupar, vazias ou preenchidas por material acelular, róseo ou acinzentado. Conclusão: A Nanoskin provocou reação inflamatória que levou à reabsorção e redução do volume do implante. Novas formulações devem ser estudadas a fim de ter um produto que seja permanente para reparo da cavidade anoftálmica.

  1. Comparison Between a Brewery Effluent and Its Receiving Stream in Ibadan Based on Their Physico; Chemical and Microbiological Analysis

    Directory of Open Access Journals (Sweden)

    Oluwayemisi Agnes Olorode

    2012-10-01

    Full Text Available This study was conducted to compare the physico - chemical and microbiological parameters of a brewery effluent and its receiving stream in Ibadan, located in south-west of Nigeria from the month of December 1993 to June 1994. Results obtained indicated that brew house effluent had a higher pH (5.2 than the receiving stream pH (4.8, lower levels of chloride ions, dissolved oxygen, total solids, conductivity and BODs than its receiving stream. Aerobic bacteria counts from sample A ( brewery effluent ranged from 180 x 103 cfu/ml to 150x103 cfu/ml and its receiving stream from 147 x 103cfu/ml to 137 x 103, while the fungi counts from 1.3 x 104 to 1.1 x 104 and 5.7 x 104 to 4.5 x 104 respectively. Total coliform counts ranged from 2.0 x 10 MPN/100 to 7.0 x 10 MPN/ 100 and 2400 x 10 MPN/100 for sample A and B respectively. Microorganism isolated include Pseudomomonas sp, Acetobacter sp., Flavobacterium sp, and Lactobacillus sp, Aspergillus niger, Curvularia sp, Alternaria sp for sample A, while Bacillus sp, Pseudomonas sp Escherichia coli, Fusarium sp, Penicillum sp 1, Penicillium sp 2, and Aspergillus sp were isolates from sample B. There was no significant difference between the values of physico-chemical of the two samples at P<0.05. Results obtained indicated that the pH between 4.8 and 5.8 obtained coupled with objectionable odour for the two water samples were below the permissible level of pH values for stream water or natural water by World Health Organization (WHO which is neutral pH of 7.0 or slightly alkaline pH 8 and the water must be colourless and odourless. The acidity level of these samples is an indication of water pollution in these environments due to an ineffective treatment of the brewery effluent and the proliferation of fungi isolates isolated in this study. These results clearly indicate that the brewery treated effluents in Ibadan and its receiving stream is an excellent medium for fungal growth and could also be used as a

  2. Screening and Preliminary Identification of Myxococcus fulvus strain%一株橙色黏球菌的筛选及初步鉴定

    Institute of Scientific and Technical Information of China (English)

    惠明; 张宜涛; 田青; 张开平

    2012-01-01

    Myxobacteria have been enriched and isolated by cell and cellulose induction methods from the soil sample. The pure strains are used for testing of antibacterial spectrum, and the strain hg59 with high activity is identified. The results show that the strain is gram-negative, rod shape, size (5-8) μm× (0. 3~0. 6)μm, sticky spores oval or oval-shaped, light yellow colonies at initial stage of growth, gradual into orange, thin to the edge of the expansion, sliding, having antibacterial activities to the G+,G- bacteria, and the effect on Bacillus subtilis and Acetobacter is significant, but on Aspergillus oryzae is poor. With the following identifications of colony morphology, physiological and biochemical experiments and 16S rDNA sequence a-nalysis, the strain is identified as Myxococcus fulvus.%从土样中通过菌体诱导和纤维素诱导法来富集和选择性分离黏细菌,将初筛菌株进行抗菌谱测定,挑选抑菌活性强的一株(编号为hg59)进行系统分类鉴定.结果表明:该菌株革兰氏染色阴性,营养细胞呈杆状,两头稍尖,大小(5~8)μm×(0.3~0.6) μm,黏孢子为卵圆形或椭圆形,菌落生长初期为淡黄色,渐变成橙黄色,薄而向边缘扩展,有滑动痕迹,对G+,G-菌均具有抑菌活性,其中对枯草芽孢杆菌和醋酸杆菌抑菌效果明显,对米曲霉则较差.经形态观察、生理生化测定和16S rDNA序列分析,初步鉴定为橙色黏球菌(Myxococcus fulvus strain).

  3. 循环喷淋发酵制备醋酸工艺的优化%Optimization of Preparation Technology of Acetic Acid by Circulating Spraying Fermentation

    Institute of Scientific and Technical Information of China (English)

    杨勇; 汪超; 徐梅; 黄红霞; 康旭; 徐宁; 李冬生

    2013-01-01

    Acetic acid bacteria(Acetobacter sp.) was used to ferment vinegar.The fermentation rate and vinegar yield of static fermentation,shake flask fermentation and circulation spraying fermentation were compared.And the fermentation conditions of circulation spraying fermentation were optimized by single factor experiments and orthogonal test.The results showed that compared with static fermentation and shake flask fermentation,circulation spraying fermentation could shorten the fermentation time while increase the fermentation yield.The optimum circulation spraying fermentation conditions were using corn cob as fermentation bed carrier; fermentation time,24 h; fermentation temperature,32 ℃; pumping capacity,2.7 L/min; inoculum concentration,75 g/L; volume fraction of ethanol,8%.Yield of vinegar could be up to 1.93 g/100 mL under these conditions.%采用醋酸菌(A cetobacter sp.)发酵生产醋酸,考察了静置发酵、摇床发酵和循环喷淋发酵3种发酵方式对发酵速度和醋酸产量的影响,设计单因素试验和正交试验优化循环喷淋发酵的工艺条件.结果表明,与静置发酵和摇床发酵相比,循环喷淋发酵可以有效缩短发酵时间,提高醋酸产量.优化的循环喷淋发酵条件为玉米芯作菌床载体、发酵时间24h、发酵温度32℃、发酵液流速2.7 L/min、接种量75 g/L、乙醇体积分数8%,醋酸产量可达1.93 g/100 mL.

  4. 利用大豆糖蜜制备细菌纤维素%Fermentation of Soybean Molasses for Bacterial Cellulose Preparation

    Institute of Scientific and Technical Information of China (English)

    吕鸿皓; 黄莉; 党苗苗; 费楠; 曹亮; 吴磊; 夏秀芳

    2015-01-01

    选用大豆糖蜜为发酵基质,利用木醋杆菌发酵制备细菌纤维素。研究糖蜜浓度、酵母浸粉添加量、发酵时间、发酵温度、接种量以及初始pH对细菌纤维素合成量、持水性和复水率的影响,结果表明:大豆糖蜜营养丰富,在大豆糖蜜浓度为15%时,在其中添加1.5%酵母浸粉、接种量为6%、初始pH4.5、30℃恒温静止发酵6 d后细菌纤维素合成量为1.17 g/100 mL,持水性为98.16%,复水率为292%,并利用傅里叶红外分析表明产物为细菌纤维素。%Bacterial cellulose (BC) was prepared from soybean molasses fermented by Acetobacter xylinum. The research explored parts of fermentation conditions on bacterial cellulose production , water holding capacity and rehydration rate as well, such as the soy molasses concentration, the amount of yeast extract, fermentation time, fermentation temperature, inoculum size and the initial pH. Results showed that the soybean molasses was rich in nutrients. The yield of BC was 1.17 g/100 mL when 15%soy molasses with the addition of 1.5%yeast extract was conducted to static fermentation at pH 4.5 , 6%inoculum size and 30℃for 6 days. Water holding capacity of bacterial cellulose was 98.16 %, bacterial cellulose rehydration was 292 %. The product was bacterial cellulose by Fourier transform infrared analysis.

  5. Cellulose Synthesis in Agrobacterium tumefaciens

    Energy Technology Data Exchange (ETDEWEB)

    Alan R. White; Ann G. Matthysse

    2004-07-31

    We have cloned the celC gene and its homologue from E. coli, yhjM, in an expression vector and expressed the both genes in E. coli; we have determined that the YhjM protein is able to complement in vitro cellulose synthesis by extracts of A. tumefaciens celC mutants, we have purified the YhjM protein product and are currently examining its enzymatic activity; we have examined whole cell extracts of CelC and various other cellulose mutants and wild type bacteria for the presence of cellulose oligomers and cellulose; we have examined the ability of extracts of wild type and cellulose mutants including CelC to incorporate UDP-14C-glucose into cellulose and into water-soluble, ethanol-insoluble oligosaccharides; we have made mutants which synthesize greater amounts of cellulose than the wild type; and we have examined the role of cellulose in the formation of biofilms by A. tumefaciens. In addition we have examined the ability of a putative cellulose synthase gene from the tunicate Ciona savignyi to complement an A. tumefaciens celA mutant. The greatest difference between our knowledge of bacterial cellulose synthesis when we started this project and current knowledge is that in 1999 when we wrote the original grant very few bacteria were known to synthesize cellulose and genes involved in this synthesis were sequenced only from Acetobacter species, A. tumefaciens and Rhizobium leguminosarum. Currently many bacteria are known to synthesize cellulose and genes that may be involved have been sequenced from more than 10 species of bacteria. This additional information has raised the possibility of attempting to use genes from one bacterium to complement mutants in another bacterium. This will enable us to examine the question of which genes are responsible for the three dimensional structure of cellulose (since this differs among bacterial species) and also to examine the interactions between the various proteins required for cellulose synthesis. We have carried out one

  6. Fermentation of Soybean Molasses for Bacterial Cellulose Preparation%利用大豆糖蜜制备细菌纤维素

    Institute of Scientific and Technical Information of China (English)

    吕鸿皓; 黄莉; 党苗苗; 费楠; 曹亮; 吴磊; 夏秀芳

    2015-01-01

    Bacterial cellulose (BC) was prepared from soybean molasses fermented by Acetobacter xylinum. The research explored parts of fermentation conditions on bacterial cellulose production , water holding capacity and rehydration rate as well, such as the soy molasses concentration, the amount of yeast extract, fermentation time, fermentation temperature, inoculum size and the initial pH. Results showed that the soybean molasses was rich in nutrients. The yield of BC was 1.17 g/100 mL when 15%soy molasses with the addition of 1.5%yeast extract was conducted to static fermentation at pH 4.5 , 6%inoculum size and 30℃for 6 days. Water holding capacity of bacterial cellulose was 98.16 %, bacterial cellulose rehydration was 292 %. The product was bacterial cellulose by Fourier transform infrared analysis.%选用大豆糖蜜为发酵基质,利用木醋杆菌发酵制备细菌纤维素。研究糖蜜浓度、酵母浸粉添加量、发酵时间、发酵温度、接种量以及初始pH对细菌纤维素合成量、持水性和复水率的影响,结果表明:大豆糖蜜营养丰富,在大豆糖蜜浓度为15%时,在其中添加1.5%酵母浸粉、接种量为6%、初始pH4.5、30℃恒温静止发酵6 d后细菌纤维素合成量为1.17 g/100 mL,持水性为98.16%,复水率为292%,并利用傅里叶红外分析表明产物为细菌纤维素。

  7. Chemical and microbiological analysis of red wines during storage at different temperatures

    Directory of Open Access Journals (Sweden)

    Attila Kántor

    2014-11-01

    for one wine sample. Microbiological parameters were observed during wine storing after filtration through different microfilters. We determined the total count of bacteria (TCB, Acetobacter cells, Lactobacillus cells, yeast and molds in wine samples with classic plate dilution method. The highest quality wines from microbiological properties were wines from 2013, which was filtered through microfilter and aseptically filled into the bottles, but wines from 2011 was filtered through cross-flow filter and samplesdirectly collected from the storage tanks without microfiltration.

  8. Fechamento de perfuração septal nasal em coelhos com celulose bacteriana Nasal septal perforation closure with bacterial cellulose in rabbits

    Directory of Open Access Journals (Sweden)

    Eulógio Emílio Martinez Neto

    2010-08-01

    Full Text Available Biomateriais podem ser válidos à somação de tecido e estrutura para o fechamento da perfuração do septo nasal. OBJETIVO: Testar celulose produzida pela bactéria Acetobacter xylinum associada à cola biológica no fechamento de perfurações septais em coelhos. Comparar histologicamente fibrose, inflamação, congestão vascular, integridade do enxerto e fechamento da perfuração septal. MATERIAL E MÉTODO: Quinze coelhos foram distribuídos em dois grupos: Controle (5 coelhos e celulose - Bionext® associado à cola de fibrina - Tissucol® (10 coelhos. Foi realizada uma perfuração cirúrgica no septo nasal em todos os coelhos. Nos animais do grupo Bionext® foi realizado o fechamento da perfuração com a colocação de celulose e aplicação de cola de fibrina. RESULTADOS: Dois coelhos foram a óbito. No grupo com celulose ocorreu o fechamento de duas perfurações e em 4 casos a celulose manteve-se impactada entre os bordos das perfurações. No grupo controle não ocorreu fechamento da perfuração septal em nenhum dos coelhos operados. CONCLUSÃO: Não houve diferença estatística significante nos quesitos inflamação aguda, congestão vascular e fibrose, avaliado histologicamente. Nos casos onde o enxerto se manteve posicionado, não houve alteração quanto à sua integridade. Pode ser útil à somação do arsenal terapêutico como base para re-epitelização dos bordos da perfuração.Alloplastic materials can be used together with tissue and structure to close nasal septal perforation. AIM: to test cellulose use in the closure of septal perforation in rabbits and to compare fibrosis, inflammation, vascular congestion and graft integrity. MATERIALS AND METHODS: Fifteen rabbits. The rabbits were divided into two groups: Control: Five rabbits and Bionext® and fibrin glue Tissucol®: Ten rabbits. Septal perforations were done in all of them. In the Bionext® group the closure was performed with the placement of cellulose

  9. 微板核酸杂交检测芽孢杆菌属的方法建立%Development of A Novel Microplate Sandwich Hybridization Assay for Detection of Bacillus

    Institute of Scientific and Technical Information of China (English)

    刘婷; 冯守帅; 辛瑜; 王武; 杨海麟

    2015-01-01

    In order to detect bacteria from the complex ecological environment for liquor-making, we developed a novel and efficient assay for identification and quantification of bacteria.We selected Bacillus to be experimental bacterium.Three oligonucleotide probes targeted 16S rRNA of Bacillus were respectively designed.Then the assay based on microplate sandwich hybridization assay with the aid of S1 nuclease treatment (S1-MSH)was developed. Meanwhile,several key operating conditions were respectively optimized.The results showed that the probes targeted Bacillus showed high accuracy for distinguishing homologous species such as Staphylococcus,Acetobacter and Pseudomonas. Besides,the assay could distinguish homologous species with the exclusion of even only one base difference when the reaction temperature of nuclease S1 was 42 ℃.When the concentrations of capture probe and signal probe were 5 nmol/L,the hybridization time were respectively 60 min and 15 min,and hybridization temperatures were 50 ℃,the color intensity was positively linear related to the cellular number,and the detection limit was low to 1.33×102 cells/mL. Therefore,this assay method could be applied for identifying and monitoring Bacillus during liquor fermentation,and the research offers an efficient method for rapid identification and quantification of microbiology in the liquor fermentation process.%以白酒发酵过程中的优势菌枯草芽孢杆菌为模式菌株,针对具有高保守性及特异性的16S rRNA设计一组核酸探针,建立了对芽孢杆菌属进行定性和定量分析的新型的微板核酸杂交检测方法,优化了关键检测条件。结果表明,当S1酶反应温度为42℃时,芽孢杆菌属检测探针能分开目标序列仅差一个碱基的近缘属。当捕获探针和信号探针工作浓度均为5 nmol/L,与分析探针杂交温度都为50℃,杂交时间分别为60 min和15 min时,检测信号的强弱与细菌数呈良好的线性关系,

  10. 山西老陈醋发酵过程中细菌群落组成与有机酸变化的关系研究%Study on the Relationship between Bacterial Community Composition and Changes of Organic Acids during Fermentation Process of Shanxi Aged Vinegar

    Institute of Scientific and Technical Information of China (English)

    杜宏福; 聂志强; 刘贤; 王敏; 郑宇

    2015-01-01

    during acetic acid fermentation.Acetic acids and lactic acids are the main organic acids,which offer over 90% of total organic acids of Shanxi aged vinegar.Canonical correspondence analysis (CCA)shows that bacteria which contribute to acetic acid formation are Acetobacter pasteurianus > Gluconacetobacter liquefaciens >Lactobacilluspanis >Lactobacillushelveticus,and bacteria which contribute to lactic acid formation are Lactobacillusreuteri >Lactobacillusmalefermentans >Lactobacillus fermentum respectively.

  11. Azospirillum, a free-living nitrogen-fixing bacterium closely associated with grasses: genetic, biochemical and ecological aspects.

    Science.gov (United States)

    Steenhoudt, O; Vanderleyden, J

    2000-10-01

    Azospirillum represents the best characterized genus of plant growth-promoting rhizobacteria. Other free-living diazotrophs repeatedly detected in association with plant roots, include Acetobacter diazotrophicus, Herbaspirillum seropedicae, Azoarcus spp. and Azotobacter. Four aspects of the Azospirillum-plant root interaction are highlighted: natural habitat, plant root interaction, nitrogen fixation and biosynthesis of plant growth hormones. Each of these aspects is dealt with in a comparative way. Azospirilla are predominantly surface-colonizing bacteria, whereas A. diazotrophicus, H. seropedicae and Azoarcus sp. are endophytic diazotrophs. The attachment of Azospirillum cells to plant roots occurs in two steps. The polar flagellum, of which the flagellin was shown to be a glycoprotein, mediates the adsorption step. An as yet unidentified surface polysaccharide is believed to be essential in the subsequent anchoring phase. In Azoarcus sp. the attachment process is mediated by type IV pili. Nitrogen fixation structural genes (nif) are highly conserved among all nitrogen-fixing bacteria, and in all diazotrophic species of the class of proteobacteria examined, the transcriptional activator NifA is required for expression of other nif genes in response to two major environmental signals (oxygen and fixed N). However, the mechanisms involved in this control can vary in different organisms. In Azospirillum brasilense and H. seropedicae (alpha- and beta-subgroup, respectively), NifA is inactive in conditions of excess nitrogen. Activation of NifA upon removal of fixed N seems to involve, either directly or indirectly, the signal transduction protein P(II). The presence of four conserved cysteine residues in the NifA protein might be an indication that NifA is directly sensitive to oxygen. In Azotobacter vinelandii (gamma-subgroup) nifA is cotranscribed with a second gene nifL. The nifL gene product inactivates NifA in response to high oxygen tension and cellular

  12. Azospirillum, a free-living nitrogen-fixing bacterium closely associated with grasses: genetic, biochemical and ecological aspects.

    Science.gov (United States)

    Steenhoudt, O; Vanderleyden, J

    2000-10-01

    Azospirillum represents the best characterized genus of plant growth-promoting rhizobacteria. Other free-living diazotrophs repeatedly detected in association with plant roots, include Acetobacter diazotrophicus, Herbaspirillum seropedicae, Azoarcus spp. and Azotobacter. Four aspects of the Azospirillum-plant root interaction are highlighted: natural habitat, plant root interaction, nitrogen fixation and biosynthesis of plant growth hormones. Each of these aspects is dealt with in a comparative way. Azospirilla are predominantly surface-colonizing bacteria, whereas A. diazotrophicus, H. seropedicae and Azoarcus sp. are endophytic diazotrophs. The attachment of Azospirillum cells to plant roots occurs in two steps. The polar flagellum, of which the flagellin was shown to be a glycoprotein, mediates the adsorption step. An as yet unidentified surface polysaccharide is believed to be essential in the subsequent anchoring phase. In Azoarcus sp. the attachment process is mediated by type IV pili. Nitrogen fixation structural genes (nif) are highly conserved among all nitrogen-fixing bacteria, and in all diazotrophic species of the class of proteobacteria examined, the transcriptional activator NifA is required for expression of other nif genes in response to two major environmental signals (oxygen and fixed N). However, the mechanisms involved in this control can vary in different organisms. In Azospirillum brasilense and H. seropedicae (alpha- and beta-subgroup, respectively), NifA is inactive in conditions of excess nitrogen. Activation of NifA upon removal of fixed N seems to involve, either directly or indirectly, the signal transduction protein P(II). The presence of four conserved cysteine residues in the NifA protein might be an indication that NifA is directly sensitive to oxygen. In Azotobacter vinelandii (gamma-subgroup) nifA is cotranscribed with a second gene nifL. The nifL gene product inactivates NifA in response to high oxygen tension and cellular

  13. 密闭法生物合成小口径细菌纤维素管%Biosynthesis of Small Caliber Bacterial Cellulose Tube by Enclosure Method

    Institute of Scientific and Technical Information of China (English)

    陈欢; 胡凌俊; 陈胜杰; 曹献英

    2012-01-01

    [Objective] To explore the feasibility of biosynthesizing small caliber bacterial cellulose tube by using the batch enclosure method to culture Acetobacter xylinum, and characterize the tube. [ Method] I1 sing coconut water as medium and silicone tube as the vector of oxygen permeation, bacterial cellulose tube was cultured in closed vessel. Then the water content and porosity of cultured products were determined, the effects of thermal drying and freeze drying on cultured products were compared, and the cultured products were scanned. [ Result] Small caliber bacterial cellulose tube can be synthesized by using batch closed culture method. Compared thermal drying with freeze drying, the latter was more suitable to tube storage and next research, compact mesh structure of tube wall and layered structure of tube section were observed by using SEM to scan tube wall and cross section. [Conclusion] Small caliber bacterial cellulose tube can be synthesized by using batch closed culture method, and tube wall with nanometer aperture had potential to be used as separation membrane.%[目的]采用间歇式密闭培养法培养木醋杆菌,探讨该方法合成小口径细菌纤维素管的可行性并对管进行表征研究.[方法]以椰子水为培养基、硅胶管为渗氧载体,在密闭罐中培养木醋杆菌,以合成小口径细菌纤维素管,之后测定产物的湿态含水率,孔隙率,比较热干燥与冷冻干燥2种干燥条件的差异,并通过扫描电镜(SEM)观察培养产物的形貌.[结果]密闭式间歇培养法能生物合成小口径细菌纤维素管;通过不同干燥条件的比较发现,相比于热干燥,冷冻干燥更适合于管的储存及后续工作;通过扫描电镜观察合成的管壁及横截面结构,发现该管壁处有较致密的网孔结构,且管断面有明显的层状结构.[结论]小口径细菌纤维素管可通过间歇式密闭法合成,且管的管壁有纳米级孔径,提示其有作为分离膜的潜力.

  14. Plantas de cana-de-açúcar cultivadas in vitro com antibióticos Sugar cane plants cultivated in vitro with antibiotics

    Directory of Open Access Journals (Sweden)

    Virgínia Maria Tenório Sabino Donato

    2005-02-01

    Full Text Available A contaminação por microrganismos é conhecida como um dos mais sérios problemas da cultura de tecidos de plantas, especialmente, em espécies tropicais. Com o objetivo de eliminar bactérias endofíticas, propágulos das cultivares de cana-de-açúcar Co 997, SP 70-1143 e ápices caulinares isolados de plantas, provenientes de semente botânica biparental (RB 818004 x SP 71-6949, foram cultivados in vitro, em meios de cultivo com antibióticos. No primeiro experimento, propágulos das cultivares Co 997 e SP 70-1143 foram cultivados em meio de cultivo contendo 200 e 300 mg.L-1 de amoxicilina e cefatoxima sódica durante 30 dias. Num segundo experimento, utilizou-se apenas a amoxicilina em concentrações mais elevadas ( 300, 600 e 1000 mg.L-1, com as mesmas plantas utilizadas no primeiro experimento, permanecendo em cultivo por mais 30 dias. No terceiro experimento foram utilizados ápices caulinares isolados de plantas provenientes de semente botânica biparental (RB 818004 x SP 71-6949, cultivados em meio de cultivo contendo 1000 mg.L-1 de amoxicilina, por um período de 120 dias. Após estes períodos de cultivo, testes de infecção e observações histológicas revelaram que o isolamento do ápice caulinar associado ao uso de antibiótico no meio de cultivo não foi suficiente para eliminar as bactérias endofíticas.Contamination by microrganism is known as one of the most serious problems in plant tissue cultures, especially, of tropical species. Most of the time, this contamination is derived from endophytic bacteria. With the objective of eliminating the endophytic bacteria Acetobacter diazotrophicus and Herbaspirillum spp., propagules of the cultivars Co 997, SP 70-1143 and shoot tips of sugarcane plants, from botanical biparental seed (RB 818004 x SP 71-6949 were cultivated in vitro in culture media with antibiotic. In the first experiment, propagules of the cultivars Co 997 and SP 70-1143 were cultivated in culture media with 200

  15. Biogenic hydrogen peroxide as a possible adaptation of life on Mars: the search for biosignatures

    Science.gov (United States)

    Houtkooper, J. M.; Schulze-Makuch, D.

    2007-08-01

    The hypothesis that putative Martian organisms incorporate H2O2 into their intracellular liquids (Houtkooper and Schulze-Makuch, 2007) has significant implications, as it explains the Viking observations quite well; it provides a functional adaptation to Martian environmental conditions; and, it is feasible as an adaptation based on the biochemistry of terrestrial organisms. It would explain many of the puzzling Viking observations such as (1) the lack of organics detected by GC-MS, (2) the lack of detected oxidant(s) to support a chemical explanation, (3) evolution of O2 upon wetting (GEx experiment), (4) limited organic synthesis reactions (PR experiment), and (5) the gas release observations made (LR experiment). An intracellular liquid containing a high concentration of H2O2 has advantages such as providing a low freezing point, a source of oxygen, and hygroscopicity, allowing an organism to obtain water vapor from the Martian atmosphere or from the adsorbed layers of water molecules on mineral grains. Perhaps surprisingly, H2O2 is used by many terrestrial organisms for diverse purposes, e.g., metabolism (Acetobacter peroxidans), as defense mechanism (Bombardier beetle), and also to mediate diverse physiological responses such as cell proliferation, differentiation, and migration. The detection of H2O2-containing organisms may well suffer from the same problems as the Viking experiments: Because of the excess oxidative contents, as derived from the GEx experiment, the organisms may decompose completely into H2O, CO2, O2 and N2. This can happen when exposed to an excess of water vapor (through hyperhydration), too high a temperature or a combination of both. Therefore, the addition of too much water vapor may be fatal. Moreover, employing pyrolysis in order to detect organic molecules may result in the organisms autooxidizing completely. Although the instrument suite aboard the Phoenix Lander offers some interesting possibilities (Schulze-Makuch and Houtkooper

  16. The H2O2-H2O Hypothesis: Extremophiles Adapted to Conditions on Mars?

    Science.gov (United States)

    Houtkooper, Joop M.; Schulze-Makuch, Dirk

    2007-08-01

    The discovery of extremophiles on Earth is a sequence of discoveries of life in environments where it had been deemed impossible a few decades ago. The next frontier may be the Martian surface environment: could life have adapted to this harsh environment? What we learned from terrestrial extremophiles is that life adapts to every available niche where energy, liquid water and organic materials are available so that in principle metabolism and propagation are possible. A feasible adaptation mechanism to the Martian surface environment would be the incorporation of a high concentration of hydrogen peroxide in the intracellular fluid of organisms. The H2O2-H2O hypothesis suggests the existence of Martian organisms that have a mixture of H2O2 and H2O instead of salty water as their intracellular liquid (Houtkooper and Schulze-Makuch, 2007). The advantages are that the freezing point is low (the eutectic freezes at 56.5°C) and that the mixture is hygroscopic. This would enable the organisms to scavenge water from the atmosphere or from the adsorbed layers of water molecules on mineral grains, with H2O2 being also a source of oxygen. Moreover, below its freezing point the H2O2-H2O mixture has the tendency to supercool. Hydrogen peroxide is not unknown to biochemistry on Earth. There are organisms for which H2O2 plays a significant role: the bombardier beetle, Brachinus crepitans, produces a 25% H2O2 solution and, when attacked by a predator, mixes it with a fluid containing hydroquinone and a catalyst, which produces an audible steam explosion and noxious fumes. Another example is Acetobacter peroxidans, which uses H2O2 in its metabolism. H2O2 plays various other roles, such as the mediation of physiological responses such as cell proliferation, differentiation, and migration. Moreover, most eukaryotic cells contain an organelle, the peroxisome, which mediates the reactions involving H2O2. Therefore it is feasible that in the course of evolution, water-based organisms

  17. EFECTOS BENEFICOS DE BACTERIAS RIZOSFÉRICAS EN LA DISPONIBILIDAD DE NUTRIENTES EN EL SUELO Y LA ABSORCIÓN DE NUTRIENTES POR LAS PLANTAS A REVIEW ON BENEFICIAL EFFECTS OF RHIZOSPHERE BACTERIA ON SOIL NUTRIENT AVAILABILITY AND PLANT NUTRIENT UPTAKE

    Directory of Open Access Journals (Sweden)

    Nelson Walter Osorio Vega

    2007-06-01

    participan en el biocontrol de patógenos de plantas. Debido a estos beneficios sobre la nutrición y el crecimiento vegetal estas bacterias rizosfericas han sido llamadas “rizobacterias promotoras del crecimiento vegetal” (PGPR, por sus siglas en inglés.This paper is a review of the benefits of rhizosphere bacteria on plant nutrition. The interaction between plant and phosphate-solubilizing- bacteria is explained in more detail and used as model to illustrate the role that rhizosphere bacteria play on soil nutrient availability. Environmental conditions of rhizosphere and mycorrhizosphere are also discussed. Plants can release carbohydrates, aminoacids, lipids, and vitamins trough their roots to stimulate microorganisms in the soil. The soil volume affected by these root exudates, aproximately 2 mm from the root surface, is termed rhizosphere. Rhizosphere bacteria participate in the geochemical cycling of nutrients and determine their availability for plants and soil microbial community. For instance, in the rhizosphere there are organisms able to fix N2 forming specialized structures (e.g., Rhizobium and related genera or simply establishing associative relationships (e.g. Azospirillium, Acetobacter. On the other hand, bacterial ammonifiers and nitrifiers are responsible for the conversion of organic N compounds into inorganic forms (NH4+ and NO3- which are available for plants. Rhizosphere bacteria can also enhance the solubility of insoluble minerals that control the availability of phosphorus (native or applied using for that organic acids or producing phosphatases that act on organic phosphorus pools. The availability of sulfur, iron and manganese are also affected by redox reactions carried out by rhizosphere bacteria. Likewise, chelating agents can control the availability of micronutrients and participate in mechanisms of biocontrol of plant pathogens. Due to these and other benefits on plant growth, some rhizosphere bacteria have been called Plant Growth

  18. 西北酸菜直投式发酵剂菌株高密度培养的研究%Study on High-density Cultivation of Directed Vat Set(DVS) for Fermented Vegetables in Northwest China

    Institute of Scientific and Technical Information of China (English)

    葛宗昌; 孟宪刚

    2012-01-01

    [目的]制备出适合西北酸菜发酵的复合直投式发酵剂.[方法]前期筛选出3个菌株:产酸速率快的东方醋酸杆菌AC5,降解亚硝酸盐高的干酪乳杆菌L5,醇香味适中的东方伊萨酵母Y7.对这3种菌分别进行高密度培养研究,确定菌体增殖的最佳培养基及培养条件.[结果]确定增殖培养基的成分是马铃薯汁、番茄汁、葡萄糖、蛋白胨和磷酸盐.通过正交试验和培养条件优化得出,AC5的最佳培养基为马铃薯汁含量40 g/L、番茄汁含量80 g/L、葡萄糖含量20g/L、胰蛋白胨含量10 g/L、磷酸盐含量10 g/L,在pH5.5、30℃、150r/min下培养24h活菌数达到3.42×108 cfu/ml;L5的最佳培养基为马铃薯汁含量40g/L、番茄汁含量60 g/L、葡萄糖含量5 g/L、胰蛋白胨含量15 g/L、磷酸盐含量10 g/L,在pH 6.5、30℃、120 r/min下培养24h活菌数可达到1.93×109 cfu/ml;Y7的最佳培养基为马铃薯汁含量60 g/L、番茄汁含量60 g/L、葡萄糖含量20 g/L、胰蛋白胨含量20g/L、磷酸盐含量10 g/L,在pH 6.0、35℃、150 r/min下培养24h活菌数可达到2.74×108 cfu/ml.[结论]该研究使单位体积的活菌数有很大提高,为制备西北酸菜直投式发酵剂提供了依据.%[ Objective ] To prepare a compound DVS for fermented vegetables in Northwest China. [ Method ] Three strains were affirmed: ACS (Acetobacter orientalis) ,which produces acid fast; L5(Lactobacillus casei) , which degradates nitrite highly; Y7 (Issatchenkia orientalis) , which has rich mellow savour. Through the research on these three bacteria on the high density cultivation, the best medium and culture conditions of bacterial multiplication were determined, [Result] The compositions of medium were potato juice, tomato juice, glucose, tryptone and phosphate. The results of orthogonal test indicated that suitable medium formulations of AC5 were 40 g/L potato juice, 80 g/L tomato juice, 20 g/L glucose, 10 g/L tryptone and 10 g/L phosphate, the