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PubMed2006

Effect of gluconic acid on piglet growth performance, intestinal microflora, and intestinal wall morphology.

Gluconic acid (GA) derives from the incomplete oxidation of glucose by some Gluconobacter strains. When fed to nonruminant animals, GA is only poorly absorbed in the small intestine and is primarly fermented to butyric acid in the lower gut. This study investigated the effect of GA on in vitro growth response and metabolism of swine cecal microflora and on animal growth performance, intestinal wall morphology, and intestinal microflora. During a 24-h in vitro cecal fermentation, total gas production and maximum rate of gas production were increased by GA (linear, P < 0.001). Ammonia in cecal liquor was reduced by GA after 4, 8, and 24 h of fermentation (quadratic, P < 0.01). After 24 h of fermentation, total short-chain fatty acids, acetic acid, propionic acid, n-butyric acid, acetic to propionic acid ratio, and acetic + butyric to propionic acid ratio were linearly increased by GA (P < 0.001). In the in vivo study, 48 piglets were divided into 4 groups and housed in individual cages for 6 wk. Piglets received a basal diet with a) no addition (control) or with GA addition at b) 3,000 ppm, c) 6,000 ppm, or d) 12,000 ppm. After 6 wk, 4 animals per treatment were killed, and samples of intestinal content and mucosa were collected. Compared with control, GA tended to increase average daily gain (+13 and +14% for GA at 3,000 and 6,000 ppm, respectively; P of the model = 0.11; quadratic, P < 0.05). Daily feed consumption and gain to feed ratio were not influenced by GA. Intestinal counts of clostridia, enterobacteriaceae, and lactic acid bacteria were not affected by GA. Gluconic acid tended to increase total short-chain fatty acids in the jejunum (+174, +87, and +74% for GA at 3,000, 6,000, and 12,000 ppm, respectively; P of the model = 0.07; quadratic, P = 0.07). Morphological evaluation of intestinal mucosa from jejunum, ileum, and cecum did not show any significant differences among treatments. This study showed that feeding GA influences the composition and activity of the intestinal microflora and may improve growth performance of piglets after weaning.

Ammonia↗
PubMed1994

Molecular characterization of microbial alcohol dehydrogenases.

There is an astonishing array of microbial alcohol oxidoreductases. They display a wide variety of substrate specificities and they fulfill several vital but quite different physiological functions. Some of these enzymes are involved in the production of alcoholic beverages and of industrial solvents, others are important in the production of vinegar, and still others participate in the degradation of naturally occurring and xenobiotic aromatic compounds as well as in the growth of bacteria and yeasts on methanol. They can be divided into three major categories. (1) The NAD- or NADP-dependent dehydrogenases. These can in turn be divided into the group I long-chain (approximately 350 amino acid residues) zinc-dependent enzymes such as alcohol dehydrogenases I, II, and III of Saccharomyces cerevisiae or the plasmid-encoded benzyl alcohol dehydrogenase of Pseudomonas putida; the group II short-chain (approximately 250 residues) zinc-independent enzymes such as ribitol dehydrogenase of Klebsiella aerogenes; the group III "iron-activated" enzymes that generally contain approximately 385 amino acid residues, such as alcohol dehydrogenase II of Zymomonas mobilis and alcohol dehydrogenase IV of Saccharomyces cerevisiae, but may contain almost 900 residues in the case of the multifunctional alcohol dehydrogenases of Escherichia coli and Clostridium acetobutylicum. The aldehyde/alcohol oxidoreductase of Amycolatopsis methanolica and the methanol dehydrogenases of A. methanolica and Mycobacterium gasti are 4-nitroso-N,N-dimethylaniline-dependent nicotinoproteins. (2) NAD(P)-independent enzymes that use pyrroloquinoline quinone, haem or cofactor F420 as cofactor, exemplified by methanol dehydrogenase of Paracoccus denitrificans, ethanol dehydrogenase of Acetobacter and Gluconobacter spp. and the alcohol dehydrogenases of certain archaebacteria. (3) Oxidases that catalyze an essentially irreversible oxidation of alcohols, such as methanol oxidase of Hansenula polymorpha and probably the veratryl alcohol oxidases of certain fungi involved in lignin degradation. This review deals mainly with those enzymes for which complete amino acid sequences are available. The discussion focuses on a comparison of their primary, secondary, tertiary, and quaternary structures and their catalytic mechanisms. The physiological roles of the enzymes and isoenzymes are also considered, as are their probable evolutionary relationships.

Alcohol Dehydrogenase↗
PubMed1984

Novel glycosidase inhibitors, nojirimycin B and D-mannonic-delta-lactam. Isolation, structure determination and biological property.

A new aminosugar named nojirimycin B (1) has been isolated as its bisulfite adduct from the culture broth of Streptomyces lavendulae SF-425, together with nojirimycin. Microbiological oxidation of 1 with Gluconobacter suboxydans IAM 1829 gave a delta-lactam (2). The structures of 1 and 2 were determined to be 5-amino-5-deoxy-D-mannopyranose and D-mannonic-delta-lactam, respectively, on the basis of 1H NMR spectroscopy and X-ray structural analysis. Both 1 and 2 exhibited powerful inhibitory activity against rat epididymal alpha-mannosidase and apricot beta-glucosidase.

1-Deoxynojirimycin↗
PubMed1992

New polyenic antibiotics active against gram-positive and gram-negative bacteria. IV. Structural elucidation of enacyloxin IIa.

The chemical structure of a unique polyenic antibiotic enacyloxin IIa (former name: fr. 2) produced by Frateuria (formerly Gluconobacter) sp. W-315 has been determined by extensive spectroscopic studies, in particular by NMR spectral analysis. It has a novel non-lactonic structure involving 3,4-dihydroxycyclohexanecarboxylic acid with a chlorine-containing polyenic and polyhydroxy acyl side chain attached as an ester to the 3-hydroxyl substituent of the acid.

Acetobacteraceae↗
PubMed2003

Application of NAD-dependent polyol dehydrogenases for enzymatic mannitol/sorbitol production with coenzyme regeneration.

D-Mannitol and D-sorbitol were produced enzymatically from D-fructose using NAD-dependent polyol dehydrogenases. For the production of D-mannitol the Leuconostoc mesenteroides mannitol dehydrogenase could be used. Gluconobacter oxydans cell extract contained however both mannitol and sorbitol dehydrogenase. When this cell extract was used, the reduction of D-fructose resulted in a mixture of D-sorbitol and D-mannitol. To determine the optimal bioconversion conditions the polyol dehydrogenases were characterized towards pH- and temperature-optimum and -stability. As a compromise between enzyme activity and stability, the bioconversion reactions were performed at pH 6.5 and 25 degrees C. Since the polyol dehydrogenases are NADH-dependent, an efficient coenzyme regeneration was needed. Regeneration of NADH was accomplished by formate dehydrogenase-mediated oxidation of formate into CO2.

Culture Media↗
PubMedDate not supplied

Manufacture of a beverage from cheese whey using a "tea fungus" fermentation.

Kombucha is a sour beverage reported to have potential health effects prepared from the fermentation of black tea and sugar with a "tea fungus", a symbiotic culture of acetic acid bacteria and yeasts. Although black tea is the preferred substrate for Kombucha fermentation, other beverages have also been tested as substrates with fair results. Cheese whey is a by-product with a good amount of fermentable lactose that has been used before in the production of beverages, so the objective of this study was to test three types of whey (fresh sweet, fresh acid and reconstituted sweet) in the elaboration of a fermented beverage using a kombucha culture as inoculum. The isolation and identification of bacteria and yeasts from the fermented tea and wheys was done along with the study of the rates of change in sugar consumption, acid production and pH decrease. Several species of acetic acid bacteria (Acetobacter aceti subsp. aceti, Gluconobacter oxydans subsp. industrius, subsp. oxydans and Gluconoacetobacter xylinus) were isolated from the different kombuchas along with the yeasts Saccharomyces cerevisiae, Kluyveromyces marxianus, and Brettanomyces bruxelensis. The main metabolic products in the fermented wheys included ethanol, lactic and acetic acids. A good growth was obtained in both sweet wheys in which a pH of 3.3 and a total acid content (mainly lactic and acetic acids) of 0.07 mol/l was reached after 96 h. The sweet whey fermented beverages contained a relatively low lactose concentration (< 12 g/l). The final ethanol content was low (5 g/l) in all the fermented wheys. The whey products were strongly sour and salty non sparkling beverages.

Acetobacteraceae↗
PubMed1989

A fast spheroplast formation procedure in some 2,5-diketo-D-gluconate- and 2-keto-L-gulonate- producing bacteria.

Calcium 2-keto-L-gulonate (Ca-2-KLG, a key intermediate in vitamin C synthesis) is produced from calcium 2,5-diketo D-gluconate (Ca-2,5-DKG) by a variety of bacteria. A few bacterial species which efficiently convert glucose to Ca-2,5-DKG have been isolated in our laboratory. Our bacterial collection included species that possess the genes for production of Ca-2-KLG from Ca-2,5-DKG; however, the yield of the former is poor. A procedure for the preparation of spheroplasts in Ca-2,5-DKG- and Ca-2-KLG-producing bacteria was developed for the construction of recombinants (fusants), combining the genes for conversion of glucose to Ca-2-KLG efficiently by protoplast fusion. The standard procedure for spheroplast formation in Gram negative bacteria by the Tris-sucrose-EDTA-lysozyme system did not work in the organisms under investigation. The need for an alternative method was necessary. Our results show that, while the Tris-NaCl-EDTA-lysozyme system (pH 8.3) worked very well with bacterial strains of Gluconobacter oxydans (ATCC9937) and Acetobacter melanogenus (NCIM2259), the Tris-sucrose-EDTA-lysozyme system worked well for Erwinia herbicola (ATCC21998), Pseudomonas chlororaphis (NCIM2041) and Corynebacterium species (ATCC31090). However, none of these systems produced spheroplasts in Brevibacterium ketosoreductum (ATCC21914), for which a separate system is under development.

Bacteria↗
PubMedDate not supplied

[Subordination of the taxa of gram-negative bacteria determined by numerical analysis methods].

Various numerical methods were used to estimate the coordination of taxa of gram-negative aerobic and facultative anaerobic organoheterotrophic and chemolithotrophic bacteria. Stable phena were found to be formed by cultures belonging to the families Rhizobiaceae, Halobacteriaceae, Enterobacteriaceae, Nitrobacteriaceae (except the genus Nitrobacter), and Methylomonadaceae (except the genus Methylococcus). The unstable position was found in the genera Thermus, Zoogloea, Xanthomonas, Sulfolobus, Methylococcus, Alcaligenes, Brucella, and Acetobacter. The greatest scatter among the objects being analysed was detected among genera belonging to the family Pseudomonadaceae. The taxonomic position of these genera must be defined more precisely. The family Methylomonadaceae is related to such physiologically unique groups of microorganisms as nitrifying, sulfate-reducing, extreme thermophilic and halophilic forms. All in all, the data reported in this work show that numerical analysis can be used to specify the classification structure of bacteria. In a number of cases, the results are consistent with those changes which are performed in the Bergey Manual 9 using logical analysis (for instance, concerning the position of the genera Gluconobacter, Acetobacter, Beijerinckia, and Derxia).

Bacteriological Techniques↗
PubMed1984

[Growth rate of antibiotic-producing gram-negative bacteria on liquid nutrient media].

Glycerol-yeast medium No. 3 may be used as a seed medium in screening of antibiotic-producing strains among Acetobacter, Gluconobacter, Chromobacterium, Agrobacterium, and other genera. The medium is transparent. It provides visual instrumental control of the growth rate of the seed material and estimation of biomass augmentation. The period of the exponential phase growth of the strains tested on medium No. 3 was 2-8 hours. When no growth on medium No. 3 is observed media Nos. 1 and 2 can be used as alternative seed media.

Acetobacter↗
PubMedDate not supplied

[Biosensor models based on potentiometric and amperometric transducers for use in medicine, biotechnology, and environmental monitoring (review)].

Various types of potentiometric and amperometric biosensors are characterized: microbial sensors with Gluconobacter oxydans cells with potentiometric (pH-sensitive field-effect transistor) and amperometric (Clark-type) electrodes for determining glucose; a potentiometric enzymatic electrode with butyrylcholinesterase, which is used in the biosensor designed to detect pesticides; immunosensors with pH-sensitive field-effect transistors which detect the herbicide 2, 4-D; a biosensor for human immunoglobulin G; biosensors with anaerobic bacteria Clostridium thermocellum; chemical and enzymatic sensors containing a photosensitive membrane for determining ammonium ions and urea; and amperometric microbial sensors prepared with Pseudomonas cells for determining naphthalene, biphenyl, and polychlorinated benzoates. Practical applications of the developed models of biosensors to medicine, biotechnology, and environmental monitoring are discussed.

Biosensing Techniques↗
PubMedDate not supplied

[Sensor for rapid measurement of blood glucose].

Bacterial biosensor consisting of Gluconobacter oxydans cells immobilized on the surface of oxygen electrode was used for measuring glucose concentration in human blood serum. The results were compared with those of standard clinical method (color reaction with ortho-toluidine). The proposed biosensor permits highly accurate measurements (mean quadratic deviation no more than 2% of the mean arithmetic), the coefficient of correlation with the results of standard method being 0.970.

Acetobacteraceae↗
PubMed1998

Microbial cell-based biosensor for sensing glucose, sucrose or lactose.

Biosensors for the determination of glucose, sucrose and lactose were based on a Clark-type oxygen electrode covered with a membrane containing microbial cells. The glucose-sensing membrane was prepared with intact cells of Gluconobacter oxydans immobilized in gelatin cross-linked with glutardialdehyde. The disaccharide-sensing membranes were prepared by co-immobilization of G. oxydans with cells of Saccharomyces cerevisiae containing invertase for sucrose determination and with permeabilized cells of Kluyveromyces marxianus containing beta-galactosidase for lactose determination. The strain of G. oxydans that we used was able to oxidize both anomers of glucose at the same rate; there was therefore no need for mutarotase co-immobilization in disaccharide-sensing membranes. The sensitivity of glucose sensor was 50 nA/mM, the range of the calibration curve was 0-0.8 mM, the response time was 2 min, and the response after 1 week of storage was 62% of the initial response. The parameters of the disaccharide sensors were similar: linear range of calibration curve up to 4 mM, response time 5 min. The activities of the sensors after 1 week of storage at ambient temperature were in the range 50-65% of the initial activity.

Acetobacteraceae↗
PubMed2004

Gluconic acid production in bioreactor with immobilized glucose oxidase plus catalase on polymer membrane adjacent to anion-exchange membrane.

Gluconic acid was obtained in the permeate side of the bioreactor with glucose oxidase (GOD) immobilized onto anion-exchange membrane (AEM) of low-density polyethylene grafted with 4-vinylpiridine. The electric resistance of the anion-exchange membranes was increased after the enzyme immobilization on the membrane. The gluconic acid productions were relatively low with the GOD immobilized by any method on the AEM. To increase the enzyme reaction efficiency, GOD was immobilized on membrane of AN copolymer (PAN) adjacent to an anion-exchange membrane in bioreactor. Uses of anion-exchange membrane led to selective removal of the gluconic acid from the glucose solution and reduce the gluconic acid inhibition. The amount of gluconic acid obtained in the permeate side of the bioreactor with the GOD immobilized on the PAN membrane adjacent to the AEM under electrodialysis was about 30 times higher than that obtained with enzyme directly bound to the AEM. The optimal substrate concentration in the feed side was found to be about 1 g/l. Further experiments were carried out with the co-immobilized GOD plus Catalase (CAT) on the PAN membrane adjacent to the AEM to improve the efficiency of the immobilize system. The yield of this process was at least 95%. The storage stability of the co-immobilized GOD and CAT was studied (lost 20% of initial activity for 90 d). The results obtained clearly showed the higher potential of the dual membrane bioreactor with GOD plus CAT bound to ultrafiltration polymer membrane adjacent to the AEM. Storage stability of GOD activity in GOD plus CAT immobilized on PAN//AEM membranes and on AEM.

Acetobacter↗
PubMed2006

Coupling of enantioselective biooxidation of DL-1,2-propanediol and bioreduction of pinacolone via regeneration cycle of coenzyme.

Enantioselective biotransformation of DL-1,2-propanediol to D-2-hydroxypropanic acid was first reported by the authors. In the biooxidation process, there were some by-product formed and thus influenced the e.e. value and output of the acid. Restricting oxygen in the reaction system and offering additional proton receptor to the system displayed approving effect. The latter method constructed regeneration cycle system of coenzyme. In the article, the bioreduction of pinacolone was coupled to the enantioselective oxidation. Yield of the acid was increased by 36% and e.e. value of the product approached 99%.

Biotransformation↗
PubMed2004

Antitumor activity of levan polysaccharides from selected microorganisms.

Levans were isolated from the cultures of Gluconoacetobacter xylinus (G-levan; Mw = 40,000), Microbacterium laevaniformans (M; Mw = 710,000), Rahnella aquatilis (R; Mw = 380,000), and Zymomonas mobilis (Z; Mw = 570,000). The levans were composed mainly of fructose residues when analyzed by TLC and HPLC, and their main backbones were beta-(2,6)-linkages with beta-(2,1)-branches by GC-MS and NMR. In the in vitro antitumor activity test of the levans against eight different tumor cell lines, relatively stronger activity was observed from the SNU-1 and HepG2. The M- (52.54-62.05%) and R-levan (52.15-58.58%) showed the significantly high activity against SNU-1, while M-levan showed the highest (49.93-61.82%) activity against HepG2. During the in vivo analysis of inhibitory activity of the levans against Sarcoma-180 growth, M-, R- and Z-levans showed strong antitumor activity (average 66%) but G-levan (42%) had significantly lower activity.

Actinomycetales↗
PubMed2005

Application of molecular methods to demonstrate species and strain evolution of acetic acid bacteria population during wine production.

The growth of acetic acid bacteria on grapes or throughout the winemaking process influences the quality of wine, mainly because it increases the volatile acidity. The objective of this study was to analyse how the acetic acid bacteria population evolves in the changing environment of the grape surface and during wine fermentation. We have analysed the influence of yeast inoculation and SO2 addition on acetic acid bacteria populations. These bacteria were analysed at both the species and the strain level by molecular methods such as Restriction Fragment Length Polimorfism (RFLP) of amplified 16S rDNA, and amplification by polymerase chain reaction of Enterobacterial Repetitive Intergenic Consensus (ERIC-PCR) and Repetitive Extragenic Palindromic (REP-PCR). Our results show that the increases in population size are normally accompanied by a proliferation of Acetobacter aceti, which is the main species during fermentation. The diversity of strains is considerable in natural environments such as the grape surface. Changes in the environment during alcoholic fermentation substantially reduce the survival and the diversity of acetic acid bacteria. Few strains are able to survive these conditions and they seem to originate from both the grapes and the winery. To the best of our knowledge this is the first time that acetic acid bacteria are analysed at the strain level in grape surfaces and during winemaking.

Acetic Acid↗
PubMed2005

Characterization of acetic acid bacteria in "traditional balsamic vinegar".

This study evaluated the glucose tolerance of acetic acid bacteria strains isolated from Traditional Balsamic Vinegar. The results showed that the greatest hurdle to acetic acid bacteria growth is the high sugar concentration, since the majority of the isolated strains are inhibited by 25% of glucose. Sugar tolerance is an important technological trait because Traditional Balsamic Vinegar is made with concentrated cooked must. On the contrary, ethanol concentration of the cooked and fermented must is less significant for acetic acid bacteria growth. A tentative identification of the isolated strains was done by 16S-23S-5S rDNA PCR/RFLP technique and the isolated strains were clustered: 32 strains belong to Gluconacetobacter xylinus group, two strains to Acetobacter pasteurianus group and one to Acetobacter aceti.

Acetic Acid↗
PubMed2003

Palladium-bacterial cellulose membranes for fuel cells.

Bacterial cellulose is a versatile renewable biomaterial that can be used as a hydrophilic matrix for the incorporation of metals into thin, flexible, thermally stable membranes. In contrast to plant cellulose, we found it catalyzed the deposition of metals within its structure to generate a finely divided homogeneous catalyst layer. Experimental data suggested that bacterial cellulose possessed reducing groups capable of initiating the precipitation of palladium, gold, and silver from aqueous solution. Since the bacterial cellulose contained water equivalent to at least 200 times the dry weight of the cellulose, it was dried to a thin membranous structure suitable for the construction of membrane electrode assemblies (MEAs). Results of our study with palladium-cellulose showed that it was capable of catalyzing the generation of hydrogen when incubated with sodium dithionite and generated an electrical current from hydrogen in an MEA containing native cellulose as the polyelectrolyte membrane (PEM). Advantages of using native and metallized bacterial cellulose membranes in an MEA over other PEMs such as Nafion 117 include its higher thermal stability to 130 degrees C and lower gas crossover.

Biocompatible Materials↗