Anomeric Proton and Carbon (H1-C1) NMR Chemical Shifts of Antigenic Mannans Obtained from Pathogenic Yeast <i>Candida tropicalis</i>

On two dimensional maps of 1H-13C correlation spectroscopy (H-C COSY) analysis for the mannan of Candida tropicalis, nine cross peaks of anomeric proton and carbon were useful for the purpose of obtaining information on the chemical structure of this molecule. Namely, the mannans was comb-like structure constructed with the linear α-1,6-linked polymannnosyl backbone and several oligomannnosyl side chains composed of α-1,2-, α-1,3-, and β-1,2-linkages. Therefore, in the structural investigation of comb-like mannan, two-dimensional H-C COSY analysis is as useful as two-dimensional nuclear Hartmann-Hahn (HOHAHA) analysis.

Mannan oligosaccharides alleviate oxidative injury in the head kidney and spleen in grass carp(Ctenopharyngodon idella)via the Nrf2 signaling pathway after Aeromonas hydrophila infection

Background Mannan oligosaccharides(MOS)are recommended as aquaculture additives owing to their excellent antioxidant properties.In the present study,we examined the effects of dietary MOS on the head kidney and spleen of grass carp(Ctenopharyngodon idella)with Aeromonas hydrophila infection.Methods A total of 540 grass carp were used for the study.They were administered six gradient dosages of the MOS diet(0,200,400,600,800,and 1,000 mg/kg)for 60 d.Subsequently,we performed a 14-day Aeromonas hydrophila challenge experiment.The antioxidant capacity of the head kidney and spleen were examined using spectrophotometry,DNA fragmentation,qRT-PCR,and Western blotting.Results After infection with Aeromonas hydrophila,400-600 mg/kg MOS supplementation decreased the levels of reactive oxygen species,protein carbonyl,and malonaldehyde and increased the levels of anti-superoxide anion,antihydroxyl radical,and glutathione in the head kidney and spleen of grass carp.The activities of copper-zinc superoxide dismutase,manganese superoxide dismutase,catalase,glutathione S-transferase,glutathione reductase,and glutathione peroxidase were also enhanced by supplementation with 400-600 mg/kg MOS.Furthermore,the expression of most antioxidant enzymes and their corresponding genes increased significantly with supplementation of 200-800 mg/kg MOS.mRNA and protein levels of nuclear factor erythroid 2-related factor 2 also increased following supplementation with 400-600 mg/kg MOS.In addition,supplementation with 400-600 mg/kg MOS reduced excessive apoptosis by inhibiting the death receptor pathway and mitochondrial pathway processes.Conclusions Based on the quadratic regression analysis of the above biomarkers(reactive oxygen species,malondialdehyde,and protein carbonyl)of oxidative damage in the head kidney and spleen of on-growing grass carp,the recommended MOS supplementation is 575.21,557.58,531.86,597.35,570.16,and 553.80 mg/kg,respectively.Collectively,MOS supplementation could alleviate oxidative injury in the head kidney and spleen of grass carp infected with Aeromonas hydrophila.

Achaetomium sp.Xz8甘露聚糖酶在毕赤酵母中的表达及其酶学性质分析

甘露聚糖酶作为最主要的半纤维素酶类现已被广泛地应用在饲料、造纸、洗涤剂、食品及石油开采等领域。本研究从高温真菌Achaetomium sp.Xz8菌株中利用兼并引物和Thermal asymmetric interlaced PCR（Tail-PCR）的方法克隆获得一个新的糖苷水解酶5家族的甘露聚糖酶基因（man5Xz8）。基因全长1 239bp,序列分析发现其编码412个氨基酸和1个终止密码子,预测的信号肽序列为N端的20个氨基酸。将成熟蛋白序列克隆到毕赤酵母分泌型表达载体p PIC9中,利用甲醇诱导重组酵母菌表达目的蛋白,经SDS-PAGE电泳分析,表达蛋白分子量约55.0 k Da。对其酶学性质进行测定,Man5Xz8的最适p H值为5.0,在p H值9.0可以保持40%以上的酶活性,在p H值5.0~9.0具有良好的p H稳定性。最适作用温度为50℃,并对SDS具有较高的耐受性。以角豆胶为底物,Man5Xz8的比活、Km及Vmax值分别为101.6 U·mg-1、4.4 mg·m L-1、128.2μmol·min-1·mg-1。因此,Man5Xz8为后期研究甘露聚糖酶的工业应用和酸碱催化机制提供了良好的材料。

Gut Bacterial and Lactobacilli Communities of Weaning Piglets in Response to Mannan Oligosaccharide and Sugar Beet Pulp In vitro Fermentation

Microbiota in the gastrointestinal tract （GIT） of piglets during weaning transition can experience a sharp change which could result in growth reduction and diarrhea of weaned piglets. Dietary manipulations can play an important role in attenuating such changes caused by weaning stress. Therefore, ileal and colonic contents of weaned piglets were used as inocula, mannan oligosaccharide （MOS） or sugar beet pulp （SBP） was supplied as single energy sources to investigate effects of MOS or SBP on the shifts of gastro-intestinal microflora and lactobacilli populations. The universal bacteria- and lactobacilli-specific PCR/denaturing gradient gel electrophoresis （DGGE）, cloning and sequencing techniques were used. DGGE profiles of the universal bacteria showed that great changes were found in the position, numbers and intensity of dominant bands after fermentation. The similarity of bacterial community between ileum and colon was increased to 85-97% by MOS or SBP treatment after fermentation from the similarity with 20% before fermentation. MOS treatment significantly increased the bacterial diversity and band number in both ileal and colonic fermentation （P〈0.05）. SBP treatment significantly increased the bacterial diversity and band number in colon （P〈0.05）. It implies that some species were enriched by the addition of MOS or SBP to increase the similarity and diversity of bacterial community in weaned piglets. Five specific bands appearing in MOS or SBP treatment group after fermentation were cloned and sequenced, the changes of species related to Prevotella and Ruminococcus were observed. Two bands related to uncultured bacterium with 98% similarity were detected by MOS or SBP treatment. However, there were no effects on the similarity, diversity index and lactobacilli species revealed by MOS or SBP treatment. These results imply that MOS or SBP could have beneficial effects on the weaning piglets by stablizing microbiota in the GIT microflora.

Effect of Konjac Mannan Oligosaccharides on Growth and Antibacterial Ability of Pseudosciaena crocea

[Objective]This experiment was conducted on Pseudosciaena crocea to study the effects of mannan oligosaccharides on growth and antibacterial ability. [Method]1 500 experimental fishes were divided into five groups. The control group（ C） contained no mannan oligosaccharides,the treatment groups were contained 100,200,400,800 mg /kg of konjac mannan oligosaccharides in basal diet,respectively. The experiment continued 4 months. [Result]The results showed that Konjac Mannan oligosaccharides could significantly improve weight gain Pseudosciaena crocea. Compared with control group,Test 2 group intestine protease activity increased by 45. 74%,hepatopancreatic lipase activity increased by 31. 37%,amylase activity increased by 27. 16%. Comparison with the control group,the test group serum SOD activity was significantly higher than that in the control group（ P 〈0. 05）. Lysozyme（ LZM） activity,spleen and serum test group was significantly higher than that in the control group（ P 〈0.05）. Pseudosciaena crocea were infected by Anguillarum,compared with control group,the survival rate is higher than that of the control group（ P 〈0. 05） when the dosage of 200 mg /kg,400 mg /kg. [Conclusion]According to the test results,the Konjac Mannan oligosaccharides in the basal diet suitable dosage were 200 mg /kg.

Analysis of Clinical Characteristics and Diagnostic Value of Fungal Serology in Patients with Invasive Candidiasis

Objective: To evaluate the diagnostic value of (1 - 3)-β-D glucan and mannan assay for invasive candidiasis. Methods: A retrospective study was conducted on 32 cases in the disease group (18 proven invasive candidiasis and 14 probable invasive candidiasis) and 48 cases in the control group. The subjects were recruited from January 2018 to March 2019 in Clinical Laboratory of Hainan General Hospital. All subjects were detected by (1 - 3)-β-D glucan and mannan assay. Results: The mean concentration of (1 - 3)-β-D glucan in the disease group was 97.45 (43.23, 224.35) pg/ml and it was significantly higher than the mean concentration of the control group which was 49.85(41.91, 56.07) pg/ml (P = 0.005). The mean concentration of mannan in the disease group and the control group were 161.36 (34.96, 224.49) pg/ml and 25.80 (25.00, 29.31) pg/ml, respectively, which were significantly different (P < 0.001). The sensitivity, specificity, positive predictive value and negative predictive value of (1 - 3)-β-D glucan assay were 59.38%, 89.58%, 79.17%, 76.79%, respectively. The sensitivity, specificity, positive predictive value and negative predictive value of mannan assay were 65.63%, 95.83%, 91.30%, 80.70%, respectively. The sensitivity, specificity, positive predictive value and negative predictive value of combination of two types of assays were 81.25%, 85.42%, 78.79% and 87.23%, respectively. Conclusions: Combination of (1 - 3)-β-D glucan and mannan assay can improve diagnostic specificity and it has essential clinical diagnostic value for invasive candidiasis.

Characterization of β-1,4-D-mannanase Produced by Bacillus subtilis MSJ-5

Properties of enzyme production of a Bacillus subtitles strain （ MSJ-5 ） isolated from soil were studied in the test. Enzyme production reached the peak when MSJ-5 being cultured in fermentation medium for 32 h. 6-1,4-D-mannanase was the main component of crude enzyme solution, test results showed that the optimal reaction temperature of the enzyme was 50 ℃, the optimum reaction pH was 7.0, and the enzyme was stable when pH was 5.0 -7.0. Hydrolysis test re- suits showed that β-1,4-D-mannanase produced by MSJ-5 had significant viscosity reduction effects on Konjak mannan, and the major hydrolysis product was man- nan oligosaecharide. The results indicated that 6-1,4-D-mannanase produced by B. subtilis MSJ-5 had application potential in feed ingredients and functional oligo- saccharides industry.

Isolation of Mannooligosaccharides Corresponding to Antigenic Determinants of Pathogenic Yeast <i>Candida catenulata</i>Cell Wall Mannan

To investigate the chemical structure of cell wall mannan of pathogenic yeast, Candida catenulata IFO 0745 strain, which possess the epitopes of antigenic factors 1, 9, and 34 to genus Candida, we previously performed the two-dimensional nuclear magnetic resonance (NMR) analysis of this mannan, Fr. C, without the need for harsh procedures. In this study, three oligosaccharides, biose, triose, and tetraose, and mannose were isolated from Fr. C by acetolysis. The results of NMR analysis indicate that the chemical structures of these oligosaccharides were identified to Manα1-2Man, Manα1-2Manα1-2Man, and Manα1-3Manα1-2Manα1-2Man. The most of resultant mannose seems to be originated from the α-1,6-linked mannan backbone which is recognized by antiserum to factor 9. The inhibition assay of slide agglutination reaction between Fr. C and antigenic antibodies using three oligosaccharides indicate that the Manα1-2Manα1-2Man and Manα1-3Manα1-2Manα1-2Man possess domains corresponding to immunodominants of antigenic factors 1 and 34, respectively.

Revision on the Recent Diagnostic Strategies of Fungal Infections

Many invasive fungal diseases have no characteristic signs or symptoms, and may give negative blood cultures;therefore, clinician may decide to start empirical antifungal therapy particularly in high risk patient (e.g., hematopoietic stem cell transplant, solid organ transplant, and AIDS patients). This increases the incidence of appearance of resistant fungal strains to antifungal drugs. Traditional methods for diagnosis such as wet mount examination and microbiological cultures remain the gold standard methods for fungal disease diagnosis. However, they are time-consuming, insensitive, and have a limited impact on clinical decision-making. Significant progress has recently achieved in diagnostic tools of fungal disease. Antigen and antibody based assays, molecular techniques, and MALDI TOF spectrometry technique and nanotechnology offer more rapid, sensitive and accurate results.

Structural Investigation of Cell Wall Mannan Antigen Obtained from Pathogenic Yeast <i>Candida zeylanoides</i>

Antigenicity of pathogenic yeast Candida zeylanoides NBRC 10326 was found to have similar to that of Candida guilliermondii, but it was slightly different, i.e. NBRC 10326 strain cells react strongly with the factor antibodies 1, 4, and 9, and react relatively weakly with factor antibody 5. We have investigated the structural characteristic of cell wall mannan of this strain using a non-degradable method, nuclear magnetic resonance analysis. The results obtained from NMR analysis, the two-dimensional homonuclear Hartmann-Hahn, indicated that C. zeylanoides mannan contains α-1, 3-linked and β-1,2-linked oligomannosyl side chains corresponding to C. guilliermondii specific antigenic factor 9. In addition, it was found that the mannan contains β-1,2-linked oligomannosyl side chains attached to phosphate groups corresponding to anitigenic factor 5, which were not found in C. guilliermondii mannan.

Determination of <i>α</i>-1,3-Linked Mannose Residue in the Cell Wall Mannan of <i>Candida tropicalis</i>NBRC 1400 Strain

To investigate the chemical structure of cell wall mannan obtained from pathogenic yeast, Candida tropicalis NBRC 1400 (former antigenic standard strain, IFO 1400). As a result of two-dimensional NMR analysis, it was shown that the mannan of this strain is composed of α-1,6-, α-1,3-, α-1,2- and β-1,2-linked mannose residues. In this research, the mannan was subjected to three degradation procedures, acid-treatment, α-mannosidase, and acetolysis under two conditions in order to determine the chemical structure of the antigenic oligomannosyl side chains in this molecule. The 1H-nuclear magnetic resonance spectra of resultant oligosaccharides, pentaose and hexaose, demonstrated the existence of the oligomannosyl side chains corresponding to Manα1-3Manα1-2Manα1-2Manα1-2Man and Manα1-3Manα1-2Manα1-2Manα1-2Manα1-2Man, respectively, which have previously also been found in Candida albicans serotype A strain mannans. These findings indicate that C. tropicalis and C. albicans serotype A have no significant difference in the chemical structure of these cell wall mannans. Therefore, it can be interpreted that it is extremely difficult to distinguish both species by targeting the antigenic group in these mannans.

Integrated genome-wide differentiation and association analyses identify causal genes underlying breeding-selected grain quality traits in japonica rice

Improving grain quality is a primary objective in contemporary rice breeding.Japanese modern rice breeding has developed two different types of rice,eating and sake-brewing rice,with different grain characteristics,indicating the selection of variant gene alleles during the breeding process.Given the critical importance of promptly and efficiently identifying genes selected in past breeding for future molecular breeding,we conducted genome scans for divergence,genome-wide association studies,and map-based cloning.Consequently,we successfully identified two genes,OsMnS and OsWOX9D,both contributing to rice grain traits.OsMnS encodes a mannan synthase that increases the white core frequency in the endosperm,a desirable trait for sake brewing but decreases the grain appearance quality.OsWOX9D encodes a grass-specific homeobox-containing transcription factor,which enhances grain width for better sake brewing.Furthermore,haplotype analysis revealed that their defective alleles were selected in East Asia,but not Europe,during modern improvement.In addition,our analyses indicate that a reduction in grain mannan content during African rice domestication may also be caused a defective OsMnS allele due to breeding selection.This study not only reveals the delicate balance between grain appearance quality and nutrition in rice but also provides a new strategy for isolating causal genes underlying complex traits,based on the concept of“breeding-assisted genomics”in plants.

The Cooperative Activities of CSLD2, CSLD3, and CSLD5 Are Required for Normal Arabidopsis Development

Glycosyltransferases of the Cellulose Synthase Like D （CS/D） subfamily have been reported to be involved in tip growth and stem development in Arabidopsis. The csld2 and csld3 mutants are root hair defective and the csld5 mutant has reduced stem growth. In this study, we produced double and triple knockout mutants of CSLD2, CSLD3, and CSLD5. Unlike the single mutants and the csld2/csld3 double mutant, the csld2/csld5, csld3/csld5, and csld2/csld3/csld5 mutants were dwarfed and showed severely reduced viability. This demonstrates that the cooperative activities of CSLD2, CSLD3, and CSLD5 are required for normal Arabidopsis development, and that they are involved in important processes besides the specialized role in tip growth. The mutant phenotypes indicate that CSLD2 and CSLD3 have overlapping functions with CSLD5 in early plant development, whereas the CSLD2 and CSLD3 proteins are non-redundant. To determine the biochemical function of CSLD proteins, we used transient expression in tobacco leaves. Microsomes containing heterologously expressed CSLD5 transferred mannose from GDP-mannose onto endogenous acceptors. The same activity was detected when CSLD2 and CSLD3 were coexpressed but not when they were expressed separately. With monosaccharides as exogenous acceptors, microsomal preparations from CSLD5-expressing plants mediated the transfer of mannose from GDP-mannose onto mannose. These results were supported by immunodetection studies that showed reduced levels of a mannan epitope in the cell walls of stem interfascicular fibers and xylem vessels of the csld2/csld3/csld5 mutant.

A STUDY ON RADIOPROTECTIVE PROPERTIES OF YEAST MANNAN

Isolation and characterization of yeast mannan from Saccharomyces cerivisiae were studied. It was demonstrated that mannan was completely composed of single sugar D-mannose with molecular weight of 80KD and [α]D20+87° （0.23%, water）, and contained 99.5% carbohydrate and 0.13% protein.The freshly prepared samples and old ones give sharp peaks and

Influence of dietary mannan oligosaccharides supplementation on fingerling clownfish, Amphiprion ocellaris (Cuvier, 1830)

Objective: To test the effects of dietary mannan oligosaccharides (MOS) on clownfish Amphiprion ocellaris (A. ocellaris). Methods: Six levels (0.5, 1.0, 1.5, 2.0, 2.5 and 3.0 g/kg diet) of MOS were added to the basal diet (used as control diet) and fed clownfish A. ocellaris [total length (24.21 ± 0.16) mm] for 70 days. Growth performance and tissue protein were measured. Results: The result showed that growth rate was enhanced significantly in fish fed 0.10% and 0.15% MOS in diets compared to fish fed other MOS levels or control (P < 0.05). Survival rate significantly increased in fish fed diets with 0.20% and 0.25% MOS, compared to control. Fraction rates of protein growth were significantly higher in fish fed diets with 0.15%, 0.20%and 0.25% MOS supplementation than those fish fed other MOS inclusion levels and the control (P < 0.04). Dietary MOS concentrations and clownfish growth rates were significantly correlated. Optimal MOS concentration was predicted to be 0.185%, 0.173% and 0.171% at Days 14, 42 and 70, respectively. Conclusions: In conclusion, MOS-supplemented diet benefits for boosting growth, survival and body composition of the clownfish, A. ocellaris.

Association of mannan-binding lectin gene polymorphisms with progression of severe lupus nephritis

Objective To investigate the association of single nucleotide polymorphisms(SNPs)of the mannan-binding lectin(MBL)gene with serum levels,development,progression and prognosis of severe lupus nephritis(LN).Methods A total of 107 severe lupus nephritis patients were enrolled in the study from January 2003 to October2013.Integrated capillary electrophoresis was used to detect MBL gene polymorphism in peripheral