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 ...
Energy Citations Database
It was shown that Acetobacter xylinum cellulose gel-films can sorb silver and selenium nanoparticles stabilized by N-poly(vinyl-2-pirrolidone). The structure of original cellulose matrix, isolated nanoparticles and cellulose with sorbed nanoparticles was characterized by electron diffraction, electron microscopy, small- and wide-angle x-ray scattering ...
NASA Astrophysics Data System (ADS)
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 ...
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. ...
Jun 16, 2011 ... Keywords: Cellulose, Chemical structure, Enzymes, Crystals, Biodegradation, Acetobacter xylinum. View and Print this Publication (219 KB) ...
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of cellulose production by the gram negative bacterium,. Acetobacter xylinum, ..... however, the goals are to obtain sufficient quantity of cellulose ...
NASA Website
Recent advancements in cellulose biogenesis are presented with the objective of providing a ground-work for continuing and future investigations. 69 references, 54 figures.
... obtain plenty of oxygen, which they require for growth, multiplication, and ... be decomposing, and/or possibly providing protection from predators or ... ...
NBII National Biological Information Infrastructure
Specific labeling of a single row of cellulose-synthesizing complexes (terminal complexes, TC subunits, TCs, or TC arrays) in Acetobacter xylinum by antibodies raised against a 93-kDa protein (the cyclic dignanylic acid-binding protein) has been demonstrated by using the sodium dodecyl sulfate (SDS)�freeze-fracture labeling (FRL) ...
PubMed Central
The nucleotide sequence of the Acetobacter xylinum uridine diphosphoglucose pyrophosphorylase gene was determined; this is the first procaryotic uridine diphosphoglucose pyrophosphorylase gene sequence reported. The sequence data indicated that the gene product consists of 284 amino acids. This finding was consistent with the results obtained by expression ...
The synthesis of an extracellular ribbon of cellulose in the bacterium Acetobacter xylinum takes place from linearly arranged, membrane-localized, cellulose-synthesizing and extrusion complexes that direct the coupled steps of polymerization and crystallization. To identify the different components involved in this process, we isolated ...
Cellulose was produced heterotrophically from different carbon substrates by carrot tissue cultures and Acetobacter xylinum (a cellulose-producing bacterium) and by castor bean seeds germinated in the dark, in each case in the presence of water having known concentration of oxygen-18 (18O). We used the relationship between the amount ...
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 ...
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 ...
Recombinant phosphoglucomutase (PGM) from Acetobacter xylinum, expressed in Escherichia coli, was produced by fermentations and subjected to purification involving ammonium sulphate fractionation, gel filtration chromatography and anion exchange chromatog...
National Technical Information Service (NTIS)
The cellulose synthesizing terminal complex consisting of subunits A, B, C, and D in Acetobacter xylinum spans the outer and inner cell membranes to synthesize and extrude glucan chains, which are assembled into subelementary fibrils and further into a ribbon. We determined the structures of subunit D ...
A genomic clone bank of Acetobacter polyoxogenes NBI1028 constructed in Escherichia coli by use of the expression vector pUC18 was screened with antibody raised against membrane-bound aldehyde dehydrogenase (ALDH; 75 kilodaltons [kDa]) from A. polyoxogenes NBI1028. A clone that synthesized a 41-kDa protein cross-reactive with anti-ALDH antibody was ...
Glucose-grown cells of Acetobacter xylinum oxidized acetate only when the reaction mixture was supplemented with catalytic quantities of glucose or intermediates of the citrate cycle. Extracts, prepared by sonic treatment, catalyzed the formation of oxalacetate when incubated with phosphoenolpyruvate (PEP) and bicarbonate. Oxalacetate was not formed in the ...
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E-print Network
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 ...
Acetobacter aceti ssp. xylinum genomic library was constructed using cosmid pJB8 in Escherichia coli. The gene encoding alpha-acetolactate decarboxylase (ALDC) was isolated from the library by direct measurement of ALDC activity. The ALDC gene was expressed by its own promoter in E. coli. The nucleotide sequence was determined, and an open reading frame ...
PubMed
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 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 ...
The sorption and desorption of poly(vinylpyrrolidone)-Se{sup 0} (PVP-Se{sup 0}) nanoparticles on gel films of cellulose Acetobacter xylinum (CAX) are investigated. It is revealed that the hydrodynamic radius R{sub h} of PVP-Se{sup 0} nanoparticles decreases from 57 nm in the initial solution (without CAX gel films) to 25 nm after the sorption of ...
The cytoplasmic and outer membranes of Acetobacter xylinum 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-deoxyoctulosonic acid was used to identify the outer ...
Sequence analysis of a 5.323 kb chromosomal DNA fragment from Acetobacter xylinum involved in the biosynthesis of the exopolysaccharide acetan, revealed the presence of four ace genes designated aceB, aceC, aceD and aceE. Comparison of translated gene sequences to the databanks was used to assign putative gene functions. AceB displayed strong homology to a ...
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, ...
Cellulose (in the form of printed paper) has always been the prime medium for displaying information in our society and is far better than the various existing display technologies. This is because of its high reflectivity, contrast, low cost and flexibility. There is a major initiative to push for a dynamic display technology that emulates paper (popularly known as "electronic paper"). We have ...
The effect of microgravity on cellulose synthesis using the model system of Acetobacter xylinum was the subject of recent investigations using The National Aeronautics and Space Administration's Reduced Gravity Laboratory, a modified KC-135 aircraft designed to produce 20 sec of microgravity during the top of a parabolic dive. Approximately 40 parabolas ...
The current model of cellulose biogenesis in plants, as well as bacteria, holds that the membranous cellulose synthase complex polymerizes glucose moieties from UDP-Glc into beta-1,4-glucan chains which give rise to rigid crystalline fibrils upon extrusion at the outer surface of the cell. The distinct arrangement and degree of association of the polymerizing enzyme units presumably govern ...
The physiological effects of an experimental herbicide and cellulose synthesis inhibitor, N2-(1-ethyl-3-phenylpropyl)-6-(1-fluoro-1-methylethyl)-1,3,5-triazine-2,4-diamine, called AE F150944, are described. In the aminotriazine molecular class, AE F150944 is structurally distinct from other known cellulose synthesis inhibitors. It specifically inhibits crystalline cellulose synthesis in plants ...
Bacterial cellulose (BC) is a natural hydrogel, which is produced by Acetobacter xylinum (recently renamed Gluconacetobacter xylinum) in culture and constitutes of a three-dimensional network of ribbon-shaped bundles of cellulose microfibrils. Here, a two-step purification process is presented that significantly improves the ...
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 ?g mL?1 CBD. Pollen tube staining with calcofluor showed a loss of crystallinity in the tip zone of ...
This study presents two types of natural gellous materials as cellulose resources including gellous material synthesized by Acetobacter xylinum in fermentation process of coconut water with common name Bacterial Cellulose (BC) and gellous material isolated from seed of Ocimum americanum called hydrogel. Morphological surface of BC and ...
Production of bacterial cellulose by Acetobacter xylinum ATCC 10821 and 23770 in static cultures was tested from unamended food process effluents. Effluents included low-solids (LS) and high-solids (HS) potato effluents, cheese whey permeate (CW), or sugar beet raffinate (CSB). Strain 23770 produced 10% less cellulose from glucose than did strain 10821 and ...
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 ...
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 ...
Rapid malonate-sensitive transitory formation of enol-oxaloacetate followed by slow ketonization of the product was observed after addition of malate to the mammalian succinate-ubiquinone reductase in the presence of electron acceptor. The initial rate of enol-oxaloacetate production was equal to that of malate oxidation. Oxaloacetate keto-enol tautomerase had no effect on the initial rate of ...
A method is derived for the determination of the static dielectric permittivity of ion conducting materials when this parameter is obscured by electrode polarization in as-recorded low frequency dielectric spectra. The method requires permittivity measurements at two different electrode separations, and is applicable when the electric fields created by charge separation near the electrode surfaces ...
Intact and partially acid hydrolyzed cellulose from Acetobacter xylinum were used as model substrates for cellulose hydrolysis by 1,4-beta-D-glucan-cellobiohydrolase I (CBH I) and 1,4-beta-D-endoglucanase I (EG I) from Trichoderma reesei. A high synergy between CBH I and EG I in simultaneous action was observed with intact bacterial cellulose (BC), but ...
The oxaloacetate (OAA) decarboxylase (EC 4.1.1.3) activity of Acetobacter xylinum cells grown on glucose or glycerol is the same as that of cells grown on intermediates of the citrate cycle. The enzyme was purified 92-fold from extracts, and its molecular weight was determined to be 100,000 by gel filtration. Initial velocity studies revealed marked ...
Bacterial cellulose prepared from pellicles of Acetobacter xylinum (Gluconacetobacter xylinus) is a unique biopolymer in terms of its molecular structure, mechanical strength and chemical stability. The biochemical analysis revealed that various alkali treatment methods were effective in removing proteins and nucleic acids from native membrane resulting in ...
The aim of the study is to examine thermal behavior of water within reticulated structure of bacterial cellulose (BC) films by sub-ambient differential scanning calorimetry (DSC). BC films with different carbon source, either manitol (BC (a)) or glycerol (BC (b)), were produced by Acetobacter xylinum using Hestrin and Shramm culture medium under static ...
Bacterial cellulose (BC) nanofibers were biosynthesized by Acetobacter xylinum NUST5.2, and displayed a remarkable capability for orienting TiO2 nanoparticle arrays. Large quantities of uniform BC nanofibers coated with TiO2 nanoparticles can be easily prepared by surface hydrolysis with molecular precision, resulting in the formation of uniform and ...
Triggered biodegradable composites made entirely from renewable resources are urgently sought after to improve material recyclability or be able to divert materials from waste streams. Many biobased polymers and natural fibers usually display poor interfacial adhesion when combined in a composite material. Here we propose a way to modify the surfaces of natural fibers by utilizing bacteria ( ...
A combined structural and functional model of the catalytic region of cellulose synthase is presented as a prototype for the action of processive beta-glycosyltransferases and other glycosyltransferases. A 285 amino acid segment of the Acetobacter xylinum cellulose synthase containing all the conserved residues in the globular region was subjected to ...
The production of bacteriohopanepolyols (BHPs) is widespread in many different groups of prokaryotes; however, unsaturated components are less common except amongst the acetic acid bacteria. Here we describe the characterisation of mono- (Delta(6) or Delta(11)) and diunsaturated (Delta(6,11)) bacteriohopanetetrols isolated from the acetic acid bacterium Gluconacetobacter xylinus (formerly ...
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 ...
The scaffold is an essential component in tissue engineering. A novel method to prepare three-dimensional (3D) nanofibril network scaffolds with controlled microporosity has been developed. By placing paraffin wax and starch particles of various sizes in a growing culture of Acetobacter xylinum, bacterial cellulose scaffolds of different morphologies and ...
A novel insertion sequence element, IS12528, was found to be associated with inactivation of the alcohol dehydrogenase by insertion in the adhA gene, which encodes the primary dehydrogenase subunit of the three-component membrane-bound alcohol dehydrogenase complex in Gluconobacter suboxydans. Cloning and sequencing analyses revealed that IS12528 was 905 bp in length and had a terminal inverted ...
Major efforts are presently made to develop artificial replacement tissues with optimal architectural and material characteristics, mimicking those of their natural correspondents. Encouraged by the readiness with which cellulose fibers woven by the bacteria Acetobacter xylinum can be formed into organ-like macroscopic shapes and with different microscopic ...
Cellulose, a biopolymer consisting of long chain ?-(1->4) linked glucose sugars, is used as structural material by plants and bacteria. Degradation of cellulose to glucose, a sugar easily fermented to ethanol, occurs by the enzymatic hydrolysis of cellulose by cellulase enzymes. The enzymes have a complex structure including carbohydrate binding modules and catalytic domains responsible for the ...
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 ...
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 ...
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 ...
The tea fungus 'Kombucha' is a symbiosis of Acetobacter, including Acetobacter xylinum as a characteristic species, and various yeasts. A characteristic yeast species or genus has not yet been identified. Kombucha is mainly cultivated in sugared black tea to produce a slightly acidulous effervescent beverage that is said to have ...
We previously found that AC-1, an extracellular polysaccharide, produced by Acetobacter xylinum and composed of (1,4)-beta-D-glucan with branches of glucosyl residues, showed a strong activity to induce production of interleukin-12 (IL-12) p40 and tumor necrosis factor alpha by macrophages in vitro via Toll-like receptor 4 (TLR-4) signaling. In the present ...
We previously found that AC-1, an extracellular polysaccharide, produced by Acetobacter xylinum and composed of (1,4)-?-d-glucan with branches of glucosyl residues, showed a strong activity to induce production of interleukin-12 (IL-12) p40 and tumor necrosis factor alpha by macrophages in vitro via Toll-like receptor 4 (TLR-4) signaling. In the present ...
Finding materials suitable for soft tissue replacement is an important aspect for medical devices design and fabrication. There is a need to develop a material that will not only display similar mechanical properties as the tissue it is replacing, but also shows improved life span, biocompatibility, nonthrombogenic, and low degree of calcification. Polyvinyl alcohol (PVA) is a hydrophilic ...
To comprehend the catalytic and regulatory mechanism of the cyclic diguanylic acid (c-di-GMP)-dependent cellulose synthase of Acetobacter xylinum and its relatedness to similar enzymes in other organisms, the structure of this enzyme was analyzed at the polypeptide level. The enzyme, purified 350-fold by enzyme-product entrapment, contains three major ...
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 ...
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 ...
Cotton, an important natural fiber, is a differentiated epidermal cell. The number of genes that are active in fiber cells is similar to those in leaf, ovule, or root tissues. Through differential screening of a fiber cDNA library, we isolated five cDNA clones that are preferentially expressed in fiber. One of the cDNA clones, pCKE6, corresponded to an abundant mRNA in fiber. Transcripts for E6 ...
Bacterial cellulose (BC) can be grown into any desired shape such as pellicles, pellets, and spherelike balls, depending on the cultivation method, additives, and cell population. In this study, Acetobacter xylinum (ATCC 700178) was grown in the production medium with different concentrations of carboxylmethylcellulose (CMC) and were evaluated for BC ...
Bacterial cellulose (BC) is a polysaccharide produced by Acetobacter Xylinum bacteria with interesting properties for arterial grafting and vascular tissue engineering including high-burst pressure, high-water content, high crystallinity, and an ultrafine highly pure fibrous structure similar to that of collagen. Given that compliance mismatch is one of ...
Acetobacter suboxydans does not contain an active tricarboxylic acid cycle, yet two pathways have been suggested for glutamate synthesis from acetate catalyzed by cell extracts: a partial tricarboxylic acid cycle following an initial condensation of oxalacetate and acetyl coenzyme A. and the citramalate-mesaconate pathway following an initial condensation of pyruvate and ...
The purification and characterization of an extracellular levansucrase enzyme produced by novel nitrogen-fixer Acetobacter nitrogenifigens strain RG1(T) is described. Culture conditions were optimized for maximum levansucrase production. Levansucrase purified to homogeneity by tenfold purification has a molecular weight of 65 kDa, contained four cysteine residues, polymerized ...
The mechanism of the thermal decomposition of carbohydrates is very important to the development of fuels, fibers, and paper products. To help gain more insight into the pyrolysis chemistry of cellulose, we have carried out experimental studies using Acetobacter xylinum cellulose grown on D-(1-13C)-glucose medium with incorporation levels of 1-13C of 14%, ...
Transcription factor sigma B of Bacillus subtilis controls a large stationary-phase regulon, but in no case has the physiological function of any gene in this regulon been identified. Here we show that transcription of gtaB is partly dependent on sigma B in vivo and that gtaB encodes UDP-glucose pyrophosphorylase. The gtaB reading frame was initially identified by a sigma B-dependent Tn917lacZ ...
) Acetobacter pasteurianus ATCC 6033, ii) Acetobacter turbidans ATCC 9325 en van iii) Xanthomonas citri IFO 3835 (Xanthomonas maltophilia), Achromobacter sp., Gluconobacter oxydans, en een Pseudomonas aeroginosa (Hoofdstuk 7
The ?-amino acid ester hydrolase from Acetobacter turbidans ATCC 9325 is capable of hydrolyzing and synthesizing ?-lactam antibiotics, such as cephalexin and ampicillin. N-terminal amino acid sequencing of the purified ?-amino acid ester hydrolase allowed cloning and genetic characterization of the corresponding gene from an A. turbidans genomic library. ...
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 ...
