A two-stage pH control method was employed in batch fermentation of curdlan by Alcaligenes faecalis WX-C12 where cell-growth stage was constantly controlled at pH 7.0 and stationary stage was controlled at a constant pH as well. The influence of pH control on the curdlan production was investigated. The optimal pH control of batch process for curdlan production was obtained when cell-growth stage was controlled at pH 7.0 and stationary stage was constantly controlled at pH 5.6. Production and productivity of curdlan, QP and YP/S reached 28.19 g/L, 291 mg/(L.h), 132.27 mg/(L.h.g) and 0.659, an improvement of 20.4%, 38.1%, 38.1% and 29.5% compared to a pH uncontrolled operation respectively.
Alcaligenes ; growth & development ; metabolism ; Fermentation ; Glucans ; biosynthesis ; Hydrogen-Ion Concentration ; beta-Glucans

Adult polyglucosan body disease (APBD) is a rare neurological disease, characterized by adult onset (fifth to seventh decades), progressive sensorimotor or pure motor peripheral neuropathy, upper motor neuron symptoms, neurogenic bladder, and cognitive impairment. APBD is confirmed by a sural nerve biopsy that shows the widespread presence of polyglucosan bodies in the nerve. We report a 70 year old male patient who exhibited progressive weakness in all extremities and dementia. His electrodiagnostic studies showed sensorimotor polyneuropathy and muscle pathology that consisted of polyglucosan bodies located in small peripheral nerves. This is the first case of APBD reported in Korea.
Aged ; Biopsy ; *Glucans/metabolism ; Humans ; Inclusion Bodies ; Male ; Neurodegenerative Diseases/metabolism/*pathology

In order to explore the influence of reaction temperature on the product composition, the effect of continuous temperature change (22 degrees C-60 degrees C, +/-0.1 degree C) on hydrolysis of yeast beta-glucan by endo-beta-1,3-glucanase was determined by using self-developed Biochem-temperature Characteristic Apparatus. The activation energy of enzymatic hydrolysis of yeast beta-glucan was 84.17 kJ/mol. The optimum temperature represented by accumulation of products decreased exponentially within a certain period of time. The components of the products were changed with reaction temperature. The length of oligosaccharides decreased with the increase of temperature. The main products were laminaribiose and laminaritriose at the temperature higher than 46 degrees C, while the main products were laminaripentaose and larger molecular weight components at the temperature lower than 30 degrees C. The results can provide precise parameters to control the reaction temperature of the production of 1,3-beta-D-glucooligosaccharides.
Enzyme Activation ; Glucan Endo-1,3-beta-D-Glucosidase ; chemistry ; metabolism ; Hydrolysis ; Oligosaccharides ; chemistry ; metabolism ; Temperature ; Yeasts ; metabolism ; beta-Glucans ; metabolism

Exploring excellent new pullulanase genes, and enriching pullulanase theory are of great importance to realize the industrialization of pullulanase. Three genes, pulA, pulB and pulC, encoding pullulanases, were cloned from Bacillus cereus GXBC-3 by bioinformatics analyzing the open reading frame in Bacillus cereus, annotated as putative I and II pullulanases in the GenBank database. Characteristics of these recombinant enzymes were inducible intracellular expressed in Escherichia coli, the results showed PulA was typical II pullulanase. Recombinant PulA could hydrolyze alpha-1,4- and alpha-1,6-glycosidic bonds. Its specific activity was 32.89 U/mg with an optimum temperature of 40 degrees C and optimum pH 6.5 using pullulan as substrate. And for soluble starch substrate, its specific activity was 25.71 U/mg with an optimum temperature of 50 degrees C and optimum pH 7.0. PulB and PulC were I pullulanases and only hydrolyzed alpha-1,6-glycosidic bond. The specific activities, optimum temperature and optimum pH of PulB and PulC for pullulan substrate were 228.54 U/mg, 45 degrees C, 7.0 and 229.65 U/mg, 45 degrees C, 6.5, respectively.
Bacillus cereus ; enzymology ; genetics ; Cloning, Molecular ; Escherichia coli ; Glucans ; metabolism ; Glycoside Hydrolases ; genetics ; metabolism ; Recombinant Proteins ; genetics ; metabolism

Curdlan is a water insoluble exopolysaccharide produced by Alcaligenes faecalis under nitrogen-limiting conditions. After excretion, the polysaccharide is attached the cell wall. Thus enhancement of biomass production during the cell growth phase is important to curdlan production. A strategy of increasing nitrogen source to improve biomass production was adopted for curdlan production by Alcaligenes faecalis (ATCC 31749). In the batch fermentation of curdlan, a relatively higher NH4Cl level of 3.6 g/L with continuous glucose feeding increased the cell density leading to improvement of curdlan production. However, excessive NH4Cl would inhibit curdlan production and biomass production was not improved significantly. In addition, feeding of ammonia water at the initial phase replaced NaOH solution to control pH at 7.0. Subsequently, feeding of NaOH solution was resumed to control pH at 5.6 for curdlan production after ammonia was consumed. As a result, biomass production and curdlan yield were both enhanced remarkably. Feeding of ammonia water during the first 24 h led to biomass production of 18.8 g/L. However, higher cell density did not lead to increase in curdlan production. The maximum curdlan production (72 g/L) was obtained by feeding ammonia water for the first 14 h, during which the cell density was about 11.9 g/L.
Alcaligenes faecalis ; cytology ; metabolism ; Ammonium Chloride ; pharmacology ; Cell Culture Techniques ; methods ; Cell Proliferation ; Fermentation ; beta-Glucans ; metabolism

BACKGROUNDTrichophyton rubrum is superficial fungi characteristically confined to dead keratinized tissues. These observations suggest that the soluble components released by the fungus could influence the host immune response in a cell in contact-free manner. Therefore, this research aimed to analyze whether the culture supernatant derived from T. rubrum grown in the nail medium could elicit the immune response of keratinocyte effectively.

METHODSThe culture supernatants of two strains (T1a, T XHB ) were compared for the β-glucan concentrations and their capacity to impact the innate immunity of keratinocytes. The β-glucan concentrations in the supernatants were determined with the fungal G-test kit and protein concentrations with bicinchoninic acid protein quantitative method, then HaCaT was stimulated with different concentrations of culture supernatants by adopting morphological method to select a suitable dosage. Expressions of host defense genes were assessed by quantitative polymerase chain reaction after the HaCaT was stimulated with the culture supernatants. Data were analyzed with one-way analysis of variance, followed by the least significant difference test.

RESULTSThe T. rubrum strains (T1a and T XHB ) released β-glucan of 87.530 ± 37.581 pg/ml and 15.747 ± 6.453 pg/ml, respectively into the media. The messenger RNA (mRNA) expressions of toll-like receptor-2 (TLR2), TLR4, and CARD9 were moderately up-regulated in HaCaT within 6-h applications of both supernatants. HaCaT cells were more responsive to T1a than T XHB . The slight increase of dendritic cells-specific intercellular adhesion molecule 3-grabbing nonintegrin expression was faster and stronger, induced by T1a supernatant than T XHB . The moderate decreases of RNase 7, the slight up-regulations of Dectin-1 and interleukin-8 at the mRNA level were detected only in response to T1a rather than T XHB . After a long-time contact, all the elevated defense genes decreased after 24 h.

CONCLUSIONThe culture supernatant of T. rubrum could directly and transiently activate the innate immune response of keratinocytes.

Cell Line, Tumor ; Culture Media, Conditioned ; pharmacology ; Humans ; Immunity, Innate ; drug effects ; Keratinocytes ; drug effects ; metabolism ; Trichophyton ; metabolism ; beta-Glucans ; metabolism

OBJECTIVETo investigate the buffer capacity of insoluble plaque mass including bacteria and glucans matrix.

METHODSPlaque samples (starved or incubated 1 h with 10% sucrose), Streptococcus mutans (S. mutans) mass, and insoluble/soluble glucans were titrated with 1 mmol/L HCl. Meanwhile, the density of bacteria was counted and related to buffer capacity.

RESULTSThe bacteria density had significant effects on acid buffer capacity in dental plaque, but the effect reduced with consuming sugar. S. mutans mass with no sucrose incubating contributed to the buffer capacity of (0.609 +/- 0.202) mmol/L, and S. mutans mass with 2% sucrose had only the buffer capacity of (0.099 +/- 0.047) mmol/L. In the mean time, glucans had no effect on acid buffering (0.028 - 0.032 mmol/L).

CONCLUSIONSThe bacteria including S. mutans may be the main contributor to acid buffering in plaque solid.

Acids ; Adolescent ; Adult ; Colony Count, Microbial ; Dental Caries Susceptibility ; Dental Plaque ; microbiology ; physiopathology ; Female ; Glucans ; metabolism ; Humans ; Male ; Streptococcus mutans ; metabolism ; Young Adult

The effect of initial ammonium chloride level on production of curdlan in Alcaligenesfaecalis was investigated. It was found that ammonium chloride was the limiting substrate for cell growth during the batch fermentation process. However, the cell growth and curdlan production could not be enhanced by solely increasing the initial ammonium chloride level. The pH drop in the broth due to the consumption of ammonium chloride also effected the cell growth and curdlan production. By simultaneously increasing the initial ammonium chloride concentration and implementing an optimal pH control strategy, which is to control pH at 7.0 in the growth phase, and then shift to 5.6 in the production phase, the biomass and curdlan production in batch fermentation were increased markedly. If the initial ammonium chloride concentration was increased from 1.1 g/L to 3.6 g/L, biomass concentration of 7.2 g/L was obtained, and the final curdlan concentration reached 30.5 g/L, which was 51.7% higher than that of the former case. As the cell growth was improved due to the increase of the initial ammonium chloride concentration, the agitation speed and aeration rates must be enhanced to suit the higher oxygen uptake requirement. However, as curdlan molecules is subject to the structural breakage due to the high shear stress at higher agitation speed, an overall optimal condition for both productivity and quality of curdlan should be considered comprehensively.
Alcaligenes faecalis ; drug effects ; growth & development ; metabolism ; Ammonium Chloride ; pharmacology ; Culture Media ; Dose-Response Relationship, Drug ; Fermentation ; Hydrogen-Ion Concentration ; beta-Glucans ; metabolism

Acinetobacter baumannii has emerged as one of the leading bacteria for nosocomial infections, especially in burn wards and ICUs. The bacteria can easily form biofilm and readily attach to abiotic and biotic surfaces, resulting in persistent biofilm-mediated infections. Being surrounded by self-produced extracellular polymeric substance (EPS), the microorganisms in biofilm can acquire protective property against detrimental environment and their tolerance toward antibiotics is increased. Poly-β-1-6-N-acetylglucosamine (PNAG), the common constituent of EPS in Acinetobacter baumannii, acts as the key virulence factor and plays a crucial role in biofilm formation process. This review describes the properties and functions of the PNAG and its influence on biofilm formation and drug resistance of Acinetobacter baumannii.
Acinetobacter Infections ; drug therapy ; Acinetobacter baumannii ; drug effects ; Anti-Bacterial Agents ; therapeutic use ; Biofilms ; drug effects ; growth & development ; Burns ; Cross Infection ; Drug Resistance, Multiple, Bacterial ; beta-Glucans ; metabolism

OBJECTIVETo investigate regulation function of anodonta glucan HBP-A on chondrocytes through Wnt pathway in vitro.

METHODSRat chondrocytes were cultured and differentiated induced with IL-1beta (10 ng/ml) in vitro. Chondrocytes were divided into five groups:IL-13 group,IL-1beta + IWP-2 (5 microM,Wnt pathway inhibitor) group, IL-1beta + HBP-A (0.3 mg/ml) group and IL-1beta + IWP-2 + HBP-A group. Wnt-3a, beta-catenin (24 h,48 h,72 h) and MMP-13(72 h) genes expression were detected by Rt-PCR, while beta-catenin, MMP-13, Sox-9 and coll-II (48 h) protein expression were measured by Western-blot.

RESULTSAfter induction of IL-1beta, gene expression of Wnt-3a, beta-catenin and MMP-13 were increased,so were the protein expression of beta-catenin and MMP-13. In contrast,protein expression of Sox-9 and Coll-II were declined. Following addition of HBP-A, Wnt-3a, beta-catenin and MMP-13 were shown as induction of IL-1beta, but protein expression of Sox-9 and Coll-II were upgraded. Combining HBP-A with IWP-2 led to the lowest level in Wnt-3a, beta-catenin gene and beta-catenin protein expression and highest expression of Sox-9 protein.

CONCLUSIONHBP-A could not only delay the differentiation of chondrocytes through downgrading the signal expression of Wnt/beta-catenin,but also adjust the expression of Wnt-3a, beta-catenin and Sox-9 when combinated with the Wnt inhibitor.

Animals ; Anodonta ; chemistry ; Cell Differentiation ; drug effects ; Cells, Cultured ; Chondrocytes ; cytology ; drug effects ; metabolism ; Glucans ; pharmacology ; Interleukin-1beta ; metabolism ; Rats ; Wnt Signaling Pathway ; drug effects ; Wnt3A Protein ; genetics ; metabolism ; beta Catenin ; metabolism