共查询到20条相似文献,搜索用时 31 毫秒
1.
Bilian Chen Wenlang You Jian Huang Ying Yu Weiping Chen 《World journal of microbiology & biotechnology》2010,26(5):833-840
The extracellular polysaccharide from Rhodella reticulata was separated from the culture medium followed by concentration and ethanol precipitation, and purified by anion exchange
chromatography on DEAE-Sepharose Fast Flow. This study compared the free radical-scavenging property and antioxidant activity
with various treatments of crude extracellular polysaccharides of R. reticulata. The results showed that both the crude extracellular polysaccharide and deproteinized crude extracellular polysaccharide
gave evidence of the free radical scavenging and antioxidant activity in a dose-dependent manner. The crude extracellular
polysaccharide exhibited higher free radical scavenging capacity and better antioxidant activity than the various treatments
of crude extracellular polysaccharide samples. The superoxide anion radical scavenging ability of various samples was significantly
higher compared to standard antioxidant (α-tocopherol). These results indicate that the extracellular polysaccharide of R. reticulata is a potent natural antioxidant. 相似文献
2.
Haruki Yamada Iwao Suzuki Yoshio Kumazawa Yasuhiro Kawamura Kimifusa Mizunoe Yukihiko Aramaki Toshio Miyazaki 《Biochimica et Biophysica Acta (BBA)/General Subjects》1978,538(3):627-630
Cell surface and extracellular polysaccharide fractions obtained from Dictyostelium discoideum NC-4 cultured in bacteria-free medium showed strong B-cell mitogenic activities. Upon periodate treatment of the extracellular polysaccharide fraction this activity completely disappeared. The extracellular polysaccharide fraction could also enhance the antibody response in vitro against sheep red blood cells. 相似文献
3.
H Yamada I Suzuki Y Kumazawa Y Kawamura K Mizunoe Y Aramaki T Miyazaki 《Biochimica et biophysica acta》1978,538(3):627-630
Cell surface and extracellular polysaccharide fractions obtained from Dictyostelium discoideum NC-4 cultured in bacteria-free medium showed strong B-cell mitogenic activities. Upon periodate treatment of the extra-cellular polysaccharide fraction this activity completely disappeared. The extracellular polysaccharide fraction could also enhance the antibody response in vitro against sheep red blood cells. 相似文献
4.
Reexamination of the presence and linkage of 3-hydroxybutyryl substituents in the acidic capsular polysaccharide of Rhizobium trifolii 0403.
下载免费PDF全文
![点击此处可从《Journal of bacteriology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
We resolved previous conflicting results concerning the presence of 3-hydroxybutyryl substituents on the extracellular acidic polysaccharide from Rhizobium trifolii 0403. These substituents were indeed present in the polysaccharide and in the oligosaccharide fragments obtained by hydrogen fluoride solvolysis of the extracellular and capsular polysaccharides of the bacteria grown on plates. The 3-hydroxybutyrate substituent could be removed from the polysaccharide by 10 mM sodium deuteroxide without evidence of elimination, indicating that this substituent was ester linked. 相似文献
5.
The extracellular polysaccharide of Coscinodiscus nobilis, a member of the Coscinodiscaceae, contains a highly branched heteropolysaccharide(s) containing fucose, rhamnose, mannose, d-glucose, xylose, d-glucuronic acid, galactose (trace) and half ester sulphate. The positions of linkages between the monosaccharides have been established and evidence for the linkages between d-glucuronic acid and monosaccharides was obtained. The extracellular polysaccharide contained also a chrysolaminaran, but this may have been derived from dead cells. Fucose and mannose occur also in a separate polymer. The diatom contained polysaccharide material consisting of glucose, mannose, fucose and uronic acid residues. 相似文献
6.
Production of extracellular polysaccharides by Lactobacillus delbrueckii ssp. bulgaricus NCFB 2772 grown in a chemically defined medium 总被引:1,自引:0,他引:1
G.J. Grobben J. Sikkema M.R. Smith J.A.M. de Bont 《Journal of applied microbiology》1995,79(1):103-107
Lactobacillus delbrueckii ssp. bulgaricus NCFB 2772 produced an extracellular polysaccharide when grown in a chemically defined medium with glucose or lactose as the substrate carbohydrate. The isolated extracellular polysaccharide had a sugar composition of glucose, galactose and rhamnose in a ratio of 1:6.8:0.7. The production of extracellular polysaccharides increased at higher temperatures, but the bacterium rapidly lost its polysaccharide producing ability at 47°C. Production of polysaccharides was growth-related: no polysaccharide production was found after growth had ceased. An excess carbohydrate did not result in increased polysaccharide production. 相似文献
7.
Production of a hypoglycemic, extracellular polysaccharide from the submerged culture of the mushroom, Phellinus linteus 总被引:15,自引:0,他引:15
Dong-Hyun Kim Byung-Keun Yang Sang-Chul Jeong Jun-Bo Park Sung-Pill Cho Surajit Das Jong-Won Yun Chi-Hyun Song 《Biotechnology letters》2001,23(7):513-517
Mycelial growth and extracellular polysaccharide production of Phellinus linteus were optimal at pH 5 and 25 °C. Maximum biomass production (14.2 g l–1) was after 15 d of cultivation, whereas, extracellular polysaccharide was maximal (3.5 g l–1) after 21 d. The hypoglycemic effect of the polysaccharide, investigated in streptozotocin-induced diabetic rats, decreased plasma glucose, total cholesterol and triacylglycerol concentrations by 49%, 32%, and 28%, respectively, and aspartate aminotransferase activity by 20%. The results indicate the potential of this polysaccharide to prevent hyperglycemia in diabetic patients. 相似文献
8.
《Journal of Fermentation and Bioengineering》1990,69(6):345-349
A strain of Xanthomonas cucurbitae PCSIR B-52 produced extracellular polysaccharide using partially deproteinized cheese whey without hydrolysis. A synthetic lactose-salt medium was also utilized to determine the optiomum level of lactose desirable for successfull fermentation. The amount of extracellular polysaccharide was maximised at 7.8 gl−1 in the presence of 40 gl−1 lactose. The bacterium efficiently consumed cheese whey, particularly in the presence of corn steep liquor and penicillin waste mycelium in shaken flasks. The polysaccharide, bacterial cell mass and viscosity gradients were improved as a result of efficient oxygen transfer in a mechanically agitated fermentor. A depletion in dissolved oxygen tension resulted during the exponential growth phase. The fermentation pattern of extracellular polysaccharide was also studied by repeated batch process. 相似文献
9.
Exopolysaccharide Distribution of and Bioemulsifier Production by Acinetobacter calcoaceticus BD4 and BD413 总被引:9,自引:6,他引:3
下载免费PDF全文
![点击此处可从《Applied microbiology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
The heavily encapsulated Acinetobacter calcoaceticus BD4 and the “miniencapsulated” single-step mutant A. calcoaceticus BD413 produced extracellular polysaccharides in addition to the capsular material. The molar ratio of rhamnose to glucose (3:1) in the extracellular BD413 polysaccharide fraction was similar to the composition of the capsular material. In both strains, the increase in capsular polysaccharide was parallel to cell growth and remained constant in stationary phase. The extracellular polysaccharides were detected starting from mid-logarithmic phase and continued to accumulate in the growth medium for 5 to 8 h after the onset of stationary phase. Strain BD413 produced one-fourth the total rhamnose exopolysaccharide per cell that strain BD4 did. Depending on the growth medium, 32 to 63% of the rhamnose polysaccharide produced by strain BD413 was extracellular, whereas in strain BD4 only 7 to 14% was extracellular. In all cases, strain BD413 produced more extracellular rhamnose polysaccharide than strain BD4 did. In glucose medium, strain BD413 also produced approximately 10 times more extracellular emulsifying activity than strain BD4 did. The isolated capsular polysaccharide obtained after shearing of BD4 cells showed no emulsifying activity. Thus, strain BD413 either produces a modified extracellular polysaccharide or excretes an additional substance(s) that is responsible for the emulsifying activity. Emulsions induced by the ammonium sulfate-precipitated BD413 extracellular emulsifier require the presence of magnesium ion and a mixture of an aliphatic and an aromatic hydrocarbon. 相似文献
10.
Reconstitution of emulsifying activity of Acinetobacter calcoaceticus BD4 emulsan by using pure polysaccharide and protein. 总被引:4,自引:4,他引:0
下载免费PDF全文
![点击此处可从《Applied microbiology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Acinetobacter calcoaceticus BD4 and BD413 produce extracellular emulsifying agents when grown on 2% ethanol medium. For emulsifying activity, both polysaccharide and protein fractions were required, as demonstrated by selective digestion of the polysaccharide with a specific bacteriophage-borne polysaccharide depolymerase, deproteinization of the extracellular emulsifying complex with hot phenol, and reconstitution of emulsifier activity with pure polysaccharide and a polysaccharide-free protein fraction. Chemical modification of the carboxyl groups in the polysaccharide resulted in a loss of activity. The protein required for reconstitution of emulsifying activity was purified sevenfold. The BD4 emulsan apparently derives its amphipathic properties from the association of an anionic hydrophilic polysaccharide with proteins. 相似文献
11.
Sverre MyklestadArne Haug Bjørn Larsen 《Journal of experimental marine biology and ecology》1972,9(2):137-144
The isolation of an extracellular polysaccharide from cultures of Chaetoceros affinis var. willei (Gran) Hustedt is described. The polysaccharide behaved as a homogeneous, polyanionic compound in free-boundary electrophoresis at both pH 2 and 7. It contained sulphur, presumably as sulphate half ester groups (8.7% of SO2Na), and the following monosaccharides were tentatively identified: rhamnose, fucose, arabinose, and galactose, with the two former constituting 63% of the polysaccharide preparation. The main cellular polysaccharide was a glucan and could be extracted from the cells by dilute acid. The remaining material gave, after hydrolysis, a complex mixture of monosaccharides with rhamnose as the major component. It is concluded that the extracellular polysaccharide is probably excreted from healthy cells. 相似文献
12.
Reconstitution of emulsifying activity of Acinetobacter calcoaceticus BD4 emulsan by using pure polysaccharide and protein 总被引:1,自引:0,他引:1
Acinetobacter calcoaceticus BD4 and BD413 produce extracellular emulsifying agents when grown on 2% ethanol medium. For emulsifying activity, both polysaccharide and protein fractions were required, as demonstrated by selective digestion of the polysaccharide with a specific bacteriophage-borne polysaccharide depolymerase, deproteinization of the extracellular emulsifying complex with hot phenol, and reconstitution of emulsifier activity with pure polysaccharide and a polysaccharide-free protein fraction. Chemical modification of the carboxyl groups in the polysaccharide resulted in a loss of activity. The protein required for reconstitution of emulsifying activity was purified sevenfold. The BD4 emulsan apparently derives its amphipathic properties from the association of an anionic hydrophilic polysaccharide with proteins. 相似文献
13.
Summary Two types of polysaccharides were separated from the extracellular polysaccharide produced by Anabaena flos-aquae A-37 by ion exchange chromatography. The neutral polysaccharide is composed of mainly glucose with minor amounts of xylose in a molar ratio of 8:1. Glucose is believed to constitute the polysaccharide core to which xylose is attached. The acidic polysaccharide is composed of glucose and uronic acid as the major monomers with equal amounts of xylose and ribose as the minor constituents. The molar ratio of the monomers found in the acidic polymer is 6:1:1:10 as glucose: xylose: ribose: uronic acid. Chemical analyses showed that the extracellular polysaccharide consists of more neutral polymer (62%) than the acidic polymer (38%). 相似文献
14.
Ulrike Schweiger-Hufnagel Tomoko Ono Kazuo Izumi Peter Hufnagel Naoki Morita Harumi Kaga Mikio Morita Tamotsu Hoshino Isao Yumoto Naoyuki Matsumoto Midori Yoshida Michiko Takagi Sawada Hidetoshi Okuyama 《Biotechnology letters》2000,22(3):183-187
A water-insoluble, extracellular polysaccharide was isolated from the culture medium of the snow mold fungus, Microdochium nivale, that had been cultivated in potato/dextrose broth. The polysaccharide consisted of glucose only. Its Fourier transform infrared spectrum showed a beta configuration of the C1 position of glucose. Linkage analysis of the polysaccharide showed that it had a linear structure of -(14)-linked glucose. The polysaccharide was therefore identified as cellulose. This is the first report of extracellular cellulose occurring in fungi. 相似文献
15.
K. Kirimura S. Yusa S. Rugsaseel H. Nakagawa M. Osumi S. Usami 《Applied microbiology and biotechnology》1999,52(3):421-428
When 120 mg glucose/ml was used as a carbon source, in shake culture Aspergillus niger Yang no. 2 maximally produced only 15.4 mg citric acid/ml but accumulated 3.0 mg extracellular polysaccharide/ml. The polysaccharide secreted by mycelia of Yang no. 2 in shake culture was confirmed to be an amylose-like alpha-1,4-glucan by hydrolysis analysis with acid, amylase and glucoamylase. However, in static cultures, such as semisolid and surface cultures free from physical stresses caused by shaking damage, Yang no. 2 produced more citric acid but did not accumulate the polysaccharide. With cultivation time in shake culture, the amount of extracellular polysaccharide and the viscosity of the culture broth increased. The increase of shaking speed caused a remarkable increase in the accumulation of extracellular polysaccharide, e.g. 11.2 mg extracellular polysaccharide/ml was accumulated in the medium at a shaking speed of 200 rpm. The addition of 2.0 mg carboxymethylcellulose (CMC)/ml as a viscous additive to the medium reduced drastically the amount of extracellular polysaccharide accumulated to 1.5 mg/ml, but increased the citric acid produced to 52.0 mg/ml. However, intracellular polysaccharide accumulation kept up a steady rate of 0.26 microgram/mg dried mycelium through the entire period of cultivation. The addition of 3.0 mg polysaccharide/ml purified from the culture broth to the medium at the start of a culture resulted in a decrease of extracellular polysaccharide accumulation but an increase of citric acid accumulation. From electronmicroscopic observation, cell surfaces of hyphae cultivated with CMC were smooth, while hyphae cultivated without CMC had fibrous and granular polysaccharide on the cell surface. These results suggested that Yang no. 2 secreted the polysaccharide on the cell surface as a viscous substance and/or a shock absorber to protect itself from physical stresses caused by shaking damage in shake culture. 相似文献
16.
17.
Extracellular polysaccharide production by Klebsiella pneumoniae and its relationship to virulence 总被引:14,自引:0,他引:14
Klebsiella pneumoniae serotype 1 and serotype 2 and their capsular variants were examined for production of cell-associated capsular polysaccharides and extracellular capsular polysaccharides. The virulence of these organisms in experimental animals was examined via intraperitoneal injection in mice and transtracheal inoculation into the lungs of rats. It was found that the production of either polysaccharide component correlated with the observed virulence. The extracellular polysaccharides were purified by ethanol precipitation, electrodialysis, extraction with quaternary ammonium salts, and gel filtration. These purification steps allowed for the separation and purification of both the extracellular lipopolysaccharide and the extracellular capsular polysaccharide. Purified extracellular capsular polysaccharide and extracellular lipopolysaccharide were co-injected with K. pneumoniae intraperitoneally into mice to determine if either of these substances would produce an effect on the natural course of infection in these animals. These studies showed that only purified extracellular lipopolysaccharide enhanced the virulence of K. pneumoniae when co-injected into mice, and this virulence enhancement correlated with the content of extracellular lipopolysaccharide, but not extracellular capsular polysaccharide in mixtures of these polysaccharides. Saponification of K. pneumoniae serotype 1 extracellular polysaccharides significantly decreased their virulence-enhancing capabilities in mice, further suggesting that extracellular lipopolysaccharide may play a role in these infections. 相似文献
18.
1. Comparisons of chlorophyll a, bacterial density, frequencies of dividing cells, ash-free dry mass (AFDM) and extracellular polysaccharide content were made for biofilm developing on wood (Salix) submerged in replicated stream-side flumes exposed to either ambient light (light treatment) or covered to exclude light (dark treatment). Biofilm was sampled on days 3, 6, 9 and 14 during experimental periods occurring irrMay, September, November and December. 2. There were no significant differences in bacterial cell densities, frequencies of dividing cells, AFDM or extracellular poiysaccharide content between light and dark treatments. Ash content and bacterial biomass was similar to seston, suggesting the importance of seston as a source of material accumulating in the biofilm. 3. Of total epixylic organic carbon 7.2% was estimated to be extracellular polysaccharide, and 0.8% was bacterial carbon. At least nine times more carbon was contained in extracellular polysaccharide than in bacterial biomass. 4. In the epixylon of the Ogeechee River, bacterial dynamics appear to be controlled by factors other than the availability of algal substrates. 相似文献
19.
Distribution of Enzymes Forming Polysaccharide from Sucrose and the Composition of Extracellular Polysaccharide Synthesized by Streptococcus mutans 总被引:32,自引:1,他引:31
下载免费PDF全文
![点击此处可从《Applied microbiology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
The distribution of polysaccharide-forming activity from sucrose was investigated in cultures of three strains of Streptococcus mutans by using an assay which conveniently determines total polysaccharide. The enzymatic activity for polysaccharide formation from sucrose is almost exclusively extracellular. The ratio of the fructan to glucan in the polysaccharide differs among the three strains investigated. The enzymatic activity for the formation of polysaccharide from sucrose has been shown to be bound to the cell-free polymer itself. 相似文献
20.
Emergence of Novel Streptococcus iniae Exopolysaccharide-Producing Strains following Vaccination with Nonproducing Strains
下载免费PDF全文
![点击此处可从《Applied microbiology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Marina Eyngor Yoram Tekoah Roni Shapira Avshalom Hurvitz Amir Zlotkin Avishay Lublin Avi Eldar 《Applied microbiology》2008,74(22):6892-6897
Streptococcus iniae is a major pathogen of fish, producing fatal disease among fish species living in very diverse environments. Recently, reoccurrences of disease outbreaks were recorded in rainbow trout (Oncorhynchus mykiss, Walbaum) farms where the entire fish population was routinely vaccinated. New strains are distinguished from previous strains by their ability to produce large amounts of extracellular polysaccharide that is released into the medium. Present findings indicate that the extracellular polysaccharide is a major antigenic factor, suggesting an evolutionary selection of strains capable of extracellular polysaccharide production. 相似文献