Effects of Polysaccharides from Enteromorpha prolifera on Hepatorenal Syndrome in Mice

[Objectives]This study was conducted to evaluate the protective effect of polysaccharides from Enteromorpha prolifera(PEP)on mice with hepatorenal syndrome induced by carbon tetrachloride.[Methods]A mouse hepatorenal syndrome model was induced by carbon tetrachloride.The serum levels of lipid,total antioxidant capacity,liver and kidney function,pathological changes of liver and kidney were selected to clarity the effectiveness of PEP on hepatorenal syndrome in mice.[Results]PEP effectively lowered the serum levels of lipid,increased total antioxidant capacity,improved liver and kidney injury,and alleviated pathological changes of liver and kidney of mice induced by carbon tetrachloride.[Conclusions]PEP has a potent preventive effect on hepatorenal syndrome induced by carbon tetrachloride in mice,which provides theoretical support for future clinical application of PEP.

Selenylation Modification of Degraded Polysaccharide from Enteromorpha prolifera and Its Biological Activities

Polysaccharide extracted from Enteromorpha prolifera possessed excellent biological activities,but its molecular weight was greatly high which influenced the activity.Organic Se had higher biological activities and was safer than inorganic Se species.In the present study,Enteromorpha polysaccharide was degraded to low molecular weight by free-radical degradation method of H_2O_2 and ascorbic acid.By single factor and orthogonal experiments,the optimal degradation conditions were reaction time of 2 h,reaction temperature of 50℃,H_2O_2/ascorbic acid(n/n=1:1)concentration of 15 mmol L^(-1),and solid-liquid ratio of 1:50(g mL^(-1)).Then,the degraded polysaccharide was chemically modified to obtain its selenide derivatives by nitric acid-sodium selenite method.The selenium content was 1137.29μg g^(-1),while the content of sulfate radical had no change.IR spectra indicated that the selenite ester group was formed.Degraded polysaccharide selenide was characterized and evaluated for antioxidant,antifungal and antibacterial activities.The results showed that degraded polysaccharide selenide had strong capacity of scavenging DPPH and·OH free radical.It had significant antibacterial properties for Escherichia coli,Bacillus subtilis and Salmonella spp.,and it also had significant antifungal properties for Apple anthrax.The result ascertained degradation and selenylation modification did not change the main structure of polysaccharides.It was possible that free-radical degradation was an effective way for enhancing antioxidant activity to decrease molecular weight of polysaccharides.

Effect of polysaccharide from Enteromorpha prolifera on maize seedlings under NaCl stress

In this study, a polysaccharide from Enteromorpha prolifera (EP) was extracted and its effect on maize seedlings under NaCl stress was investigated. Firstly, the components and structure of the EP were determined. We found that EP is a sulfated polysaccharide of high-molecular weight (Mw, 1 840 KDa) heteropolysaccharides and the main monosaccharide is rhamnose. The polysaccharide was applied to explore its effect on the growth of maize seedlings and its defense response under a salt stress. The results show that EP could promote the growth of maize seedlings under the salt stress. In addition, EP was shown able to significantly regulate membrane permeability and adjustment of osmotic substances such as soluble protein, soluble sugar, and proline, antioxidant enzymes containing superoxide dismutase, catalase, peroxidase, and ascorbate peroxidase. Therefore, EP is an effective salt-resistant substance for the growth of maize seedlings under NaCl stress.

Influence of bioactive sulphated polysaccharide-protein complexes on hepatocarcinogenesis, angiogenesis and immunomodulatory activities

Objective:To explore the in vivo anticancer,anti-angiogenesis and immunomodulatory efficacies of the bioactive polysaccharide isolated from cold aqueous extract of Jania rubens(JCEM) and Pterocladia capillacea(PCEM) as well as hot aqueous extract of Enteromorpha intestinalis(EHEM) against hepatocellular carcinoma rat model(HCC) and to study their chemical composition.Methods:The sugars and amino acids composition of the bioactive polysaccharides of JCEM,PCEM and EHEM were determined using gas liquid chromatography and amino acid analyzer,respectively.These polysaccharide extracts(20 mg/kg b.wt.for 5 weeks) were assessed on hepatocarcinogenesis in rats and α-fetoprotein(AFP),carcinoembryonic antigen(CEA),glypican-3(GPC-3),hepatocyte growth factor(HGF) and vascular endothelial growth factor(VEGF) and Ig G levels were evaluated.Results:The GLC analysis of JCEM,PCEM and EHEM polysaccharide revealed the presence of 10,9 and10 sugars,in addition the amino acid analyser enable identification of 16,15 and 15 amino acids,respectively.These polysaccharide extracts of JCEM,PCEM and EHEM produced significant decrease in serum AFP,CEA,GPC-3,HGF and VEGF compared with untreated HCC group.JCEM,PCEM and EHEM had an immunostimulatory responses by increasing the IgG levels as compared by naive value(1.23,1.53 and 1.17 folds),respectively.The bioactive polysaccharides in HCC induced rats improved the humoral immune response.The photomicrographs of liver tissue sections of the groups of HCC treated with polysaccharide extracts of Jania rubens and Enteromorpha intestinalis showed intact histological structure.Moreover,fractions HE1,HE4,HE7 obtained from polysaccharide of EHEM showed moderate cytotoxic activity against Hep G2 in vitro with IC_(50) 73.1,42.6,76.2 μg/mL.However,fractions of PCEM and JCEM show no or weak cytotoxicity against Hep G2 in vitro where the cytotoxic activity of their crude polysaccharide extract proved synergetic effect.Conclusions:The pronounced antitumor activity of sulphated polysaccharide-protein complexes of JCEM and EHEM is due to direct cytotoxic activity,anti-hepatocarcinogensis,and anti-angiogenesis.In addition,JCEM,PCEM and EHEM had an immunostimulatory response and improved the humoral immune response in HCC induced rats.

Biodegradation ofEnteromorpha Polysaccharides by Intestinal Micro-Community from Siganus oramin

Micro-communities are supposed to have more potential functions of biodegradation of polysaccharides than single strain; however, the intestinal mi ties involved in the biodegradation of Enteromorpha polysaccharides （EP） were sel- dom reported. In order to obtain the EP-degrading micro-community, the intestines of Siganus oramin was obtained to isolate the micro-communities, which were enriched by 0.3% of EP as the sole carbon source. A stable micro-community with EP degradative capability was achieved after seven generations of subculture, named H1. Results showed that H1 was able to degrade 75% of EP within 24 hours, and the activity of EP lyases reached 500 U mL-1 in 32 hours. With denaturing gradient gel electrophoresis （DGGE） and 16S rRNA gene clone library analysis, ten bacteria closely related to Marinomonas pontica, Microbacterium sp., Leucobacter chironomi, Cyclobacterium sp., Algoriphagus winogradskyi, Pseudoalteromonas sp. and Vibrio sp. were determined. Furthermore, compared with the DGGE bands sequence and the clone library analysis, the dominant bacteria of the EP-biodegrading mi- cro-community were Pseudoalteromonas sp. and Vibrio sp., with the respective proportion of 38% and 46%, and they should play an important role in EP degradation together with other degrading bacteria in the micro-community H1.

Inhibitory Effect of Extracellular Polysaccharide EPS-II from Pseudoalteromonas on Candida adhesion to Cornea in vitro

Objective Fungal keratitis（FK） is a vision-threatening infection,whose treatment requires more effective and safer anti-fungal agent exploitation urgently.With this aim,we focused on the effect of an extracellular polysaccharide on fungal adhesion to human corneal epithelial cells.Methods We performed the cytotoxicity assays of the extracellular polysaccharide EPS-II from an antarctic bacterium Pseudoaltermonas and evaluated its inhibitory effect on Candida albicans cells＇ adherence to human corneal epithelial cells（HCECs）.Results EPS-II,which displayed minor cytotoxicity but also promoted proliferation of HCECs,could inhibit the adherence of yeast cells to HCECs in a dose-dependent manner.EPS-II could also suppress the subsequent PI3K/AKT signaling pathway,and thereby decrease the expression of early inflammatory cytokines.Conclusions ExtracellularpolysaccharideEPS-IIwassuggestedasanewnaturalagentforattenuatingFK.

Chemical Characteristics and Anticoagulant Activities of Two Sulfated Polysaccharides from Enteromorpha linza (Chlorophyta)

Two sulfated polysaccharides, designated MP and SP, were extracted from the marine green alga Enteromorpha linza using hot water and then purified using ion-exchange and size-exclusion chromatography. The anticoagulant activities of MP and SP were examined by determination of their activated partial thromboplastin time （APTT）, thrombin time （TT） and prothrombin time （PT） using human plasma. Results showed that MP and SP were composed of abundant rhamnose with small amounts of xylose and glucuronic acid, whereas SP also contained a small amount of galactose. Approximate molecular weights of MP and SP were 535 and 502 kDa, respectively. As compared with SP, MP had higher contents of sulfate ester （19.0%） and uronic acid （14.9%）. The MP mainly consisted of （1→4）-linked rhamnose residues with partially sulfated groups at the C-3 position, and small amounts of （1→3, 4）-linked rhamnose, （1→2,4）-linked rhamnose, （1→4）-linked glucuronic acid and （1→4）-linked xylose residues. The SP contained abundant （1→4）-linked rhamnose with minor amounts of （1→3）-linked rhanmose, （1→3, 4）-linked rhamnose, （1→2, 4）-linked rhanmose, （1→4）4inked glucuronic acid, （1→4）-linked xylose, and （1→3）-linked galactose residues. The sulfate groups were mainly located at C-3 of （1→4）-linked rhamnose residues. Both MP and SP, in particular the former, effectively prolonged APTT and TT. This work demonstrates that MP and SP have unique structural characteristics distinct from those of other sulfated polysaccharides from Enteromorpha. The MP is a potential source of anticoagulant, and the difference in anticoagulant activities of the two sulfated polysaccharides is directly linked to the discrepancy of their chemical features.

浒苔多糖EPⅢ的分离与鉴定

利用乙醇分级对冻融后的浒苔热水提取物中的多糖进行了分级,得到了三个级分.采用凝胶层析法对其中一个级分进行纯化后得EPⅢ,经Sepharose CL-6B,DEAE-SepharoseCL-6B检测均为单一对称洗脱峰,紫外检测未见有蛋白吸收峰.采用Sepharose CL-6B柱层析法测得其相对分子质量为38 000.经气相色谱分析该组分的单糖组成为鼠李糖、木糖、甘露糖、半乳糖、葡萄糖,其摩尔比为12.70∶1.00∶0.64∶0.32∶19.03.

好氧颗粒污泥胞外聚合物(EPS)的生化性研究

将人工培养的好氧颗粒污泥进行饥饿试验,研究EPS的可生化性.结果表明,好氧颗粒污泥EPS是由40%可生物降解EPS和60%不可生物降解EPS组成的,其中可生物降解EPS可作为颗粒污泥自身的能源,而不可生物降解EPS则不行,但其对颗粒污泥的立体结构有巨大作用.将从新鲜好氧颗粒污泥中提取的EPS投加到好氧颗粒污泥和活性污泥中,提取的EPS均可被两者作为碳源利用,且活性污泥对EPS的利用速率是好氧颗粒污泥的1.5倍;而从饥饿好氧颗粒中提取的EPS作为两者碳源时,均没有明显的利用效果,说明不可生物降解的EPS不能作为两者的能源.

Enterococcus durans产胞外多糖EPS-Ⅰ的分离纯化和结构分析

The rough crystal of exopolysaccharide produced by Enterococcus durans, a strain of lactic acid bacteria screened from the intestine of a cock in our laboratory, was purified by CM-cellulose column chromatography, DEAE-Sephadex A-25 ionexchange and Sephadex G-100 gel chromatography to give EPS-Ⅰ. The EPS-Ⅰ was eluted as a single peak in HPLC analysis, indicating the homogeneity of EPS-Ⅰ and free from low-molecular-weight polysaccharides. The molecular weight of the EPS-Ⅰ was determined as 42 000 by the light scattering method. The result of its elemental analysis was C 41.08% and H 7.23% without the elements of N, P and S. Monosaccharide analysis showed that it was composed of Glc and Man in a molar ratio of 4∶1. Sugar composition analysis, methylation analysis and 1H and 13C NMR spectroscopy revealed that the EPS-Ⅰ was composed of pentasaccharide repeating units. The sequence of sugar residues was determined by using two-dimensional NMR, including heteronuclear multiple-bond correlation(HMBC) and nuclear overhauser effect spectroscopy(NOESY). The structure of the pentasaccharide repeating unit of EPS-Ⅰ was given, a new excellular polysaccharide from lactic acid bacterium compared with other EPSs was reported.

pH对膜污染层EPS污染特征的影响及机理分析

溶液pH值不仅影响溶质的电荷等表面性质,同时也影响膜表面的特性,从而影响溶质与膜表面之间的相互作用和溶质在膜面的沉积量及膜通量.胞外多糖(Extracellular Polysac-charides,EPS)是膜生物反应器(Membrane Bioreactor,MBR)中主要的膜污染物质之一,从实际MBR膜污染层中分离纯化得到的EPS,在EPS引起膜污染机理分析的基础上,以过滤阻力、EPS在膜表面沉积量及膜通量为评价指标,综合分析不同溶液pH对EPS污染特征的影响,可为揭示MBR中EPS膜污染的成因和机理以及污染膜的清洗提供参考.结果表明,MBR膜污染层EPS的膜污染过程较好地符合沉积阻力模型,EPS在膜表面的污染主要是EPS沉积引起的;EPS溶液的pH越高,其与膜之间的排斥力越大,沉积量越少,沉积阻力越小,膜通量越高.pH为7.0时,沉积阻力为3.34×1011m-1,沉积量为1.25 g/m2,初始相对膜通量为9.8%.

营养失衡下的分层分质EPS对异型膨胀污泥及其沉降性差异影响

为探索EPS对膨胀污泥沉降性的影响,通过减少进水P源、N源的方式培养异型膨胀活性污泥,分析不同层、不同组分EPS对异型膨胀污泥沉降性影响.结果表明:异型膨胀(非丝状菌粘性膨胀、丝状菌膨胀)活性污泥EPS多糖组分Total-PS、中层组分(L-PS)含量均高于正常污泥.非丝状菌粘性膨胀污泥EPS各层多糖含量高于丝状菌膨胀污泥,而各层蛋白质(PN)含量均低于丝状菌膨胀污泥.非丝状菌粘性膨胀污泥Total-EPS((229±94) mg/g MLSS)、PS/PN值不仅显著高于正常活性污泥((86±16)mg/g MLSS),也高于丝状菌膨胀污泥(108±30)mg/gMLSS).非丝状菌粘性膨胀污泥EPS多糖总量Total-PS、蛋白质总量Total-PN越高,SVI值越大,污泥沉降性越差,越易膨胀,且EPS蛋白质组分对污泥膨胀作用大于多糖;从不同层EPS看,松散外层(S层)EPS对非丝状菌粘性膨胀作用最大(S-PN与SVI值相关性最大,r为0.881,P<0.05),是主要影响因子.丝状菌膨胀污泥,除了内层紧密型T-PN对SVI值影响较大外,其他各层、各组分EPS含量与SVI均呈微弱负相关.

微生物胞外聚合物(EPS)对金属耐蚀性的影响

微生物胞外聚合物(EPS)对金属腐蚀具有抑制作用,研究了EPS中的主要成分蛋白质和多糖对碳钢、铸铁、黄铜和304不锈钢腐蚀速率的影响,并以此为基础,开展了蛋白质、多糖抑制碳钢腐蚀的单因素试验以及正交试验。结果表明:单因素作用下,蛋白质或多糖的质量浓度为1.0mg/mL时,碳钢的腐蚀速率最低;多因素作用下,多糖加入量为0.7mg/mL、蛋白质加入量为0.7mg/mL、浸涂时间为36h时,碳钢的腐蚀抑制效果最佳。研究结果可以为金属防护领域研发新型防腐蚀涂料提供技术支持。

缘管浒苔Enteromorpha linza粗多糖的提取、精制及性质研究

采用热水浸提、醇沉精制提取缘管浒苔粗多糖,并研究了其理化性质。热重分析表明粗多糖在180℃—280℃范围内出现快速失重,最快失重温度为243℃;紫外光谱显示其中含有蛋白质;红外光谱表明其具有多糖的特征吸收峰及硫酸基的存在。

Effect of Echinacea purpurea Polysaccharide on IL-6 m RNA Expression Level in IEC-6 Cell after LPS Injury

[Objective] The aim was to investigate the effect of Echinacea purpurea polysaccharide （EPS） on IL-6 mRNA expression level in IEC-6 cell after lipopolysac- charide （LPS） injury. [Method] Total RNA of IEC-6 cell was extracted with TRIzon reagent and amplified by R-r-PCR. The amplification products were examined by a- garose gel electrophoresis and graphed for analysis. [Result] After stimulation by LPS, the IL-6 mRNA expression level in iEC-6 cell increased. However, EPS could inhibit this effect, and the inhibitory effect was dose-dependent. At the concentration of 50 μg/ml, EPS could partially inhibit the IL-6 mRNA expression in IEC-6 cell after LPS stimulation; in the concentration range of 100-500 μg/ml, the inhibitory effect of EPS on IL-6 mRNA expression in iEC-6 cell increased with the increase of con- centration. When the IEC-6 cell was pre-treated with EPS （50, 100, 200 and 500 μg/ml） for 24 h and then stimulated with LPS （10 μg/ml） for 1 and 4 h, respectively, it was found that the LPS-induced mRNA expression of IL-6 in IEC-6 cell was in- hibited by EPS, and this kind of inhibitory effect was time-dependent. [Conclusion] After small intestinal epithelial cells were stimulated by LPS, the IL-6 mRNA expres- sion level increased. However, EPS could inhibit the LPS-induced mRNA expression of IL-6, thus protecting the intestinal mucosa. In addition, this kind of inhibitory effect showed time and concentration dependence.

从蛋白质、多糖角度理解EPS对金属腐蚀的影响

从蛋白质、多糖角度出发,综述了EPS及EPS中蛋白质、多糖特性,简要概述了EPS吸附在金属表面改变界面性质的三种途径,一是形成膜屏障、二是增强极化作用、三是改变生物膜特性,并着重分析了蛋白质、多糖在此三种途径中对金属腐蚀有怎样的影响,为EPS防腐蚀问题提出建议和发展方向,以期为未来的相关研究提供参考。

产胞外多糖嗜热链球菌eps基因簇的表达及生物信息学分析

目的:胞外多糖(EPS)作为乳酸菌(LAB)重要的次级代谢产物,在发酵乳制品的生产中发挥着重要作用。采用生物信息学方法分析乳酸菌产EPS的分子机制,为开发利用EPS提供理论依据。方法:采用二代测序技术(Illumina Hiseq 4000)及实时荧光定量PCR技术(RT-qPCR)对分离自蒙古国酸牛奶中一株高产EPS的嗜热链球菌IMAU20756进行基因组测序,并对不同时间点eps基因表达量进行定量分析。结果:该菌株基因组全长为1838440 bp,GC含量为38.8%,共编码2120个基因,包含1962个功能基因,36个t RNA、515个假基因、1个tmRNA和2个重复单位。其中和EPS生产相关的基因有12个,epsA、epsB是调控基因,epsC、epsD决定多糖链长,eps1E、eps2E、epsG、epsF、epsH、epsI、epsJ是编码糖基转移酶基因,epsK调控多糖聚合及输出。结论:所有和EPS生物合成相关的基因在发酵过程中均能表达,特别是糖基转移酶的基因表达量在发酵6 h时达最高。

黄杆菌中浒苔多糖降解有关基因的异源表达及酶活测定

浒苔绿潮爆发带来了一系列环境问题,也对浒苔资源的开发利用提出了新挑战。从生物酶法降解浒苔的主要成分浒苔多糖入手,筛选出能降解浒苔多糖的菌株,对其进行16S rRNA基因鉴定,同时对其中表达量上调的木聚糖酶基因(GH43)进行异源表达,利用紫外-可见分光光度计比色法进行酶活测定及酶学性质研究。结果表明筛选到的浒苔多糖降解菌为黄杆菌(Algibacter pacificus),克隆表达的木聚糖酶的最适温度为50℃,最适pH约为5,粗酶液酶活为65.71 U/mL。实验可为由浒苔引起的海洋污染治理问题提供理论依据,同时为该菌株及木聚糖酶的工业化利用提供了参考,有利于实现对浒苔的资源化利用。

浒苔多糖对脂多糖诱导小鼠肠道屏障功能及肠道微生物组成的影响

目的:研究浒苔多糖(Enteromorpha prolifera polysaccharide,EP)对脂多糖(lipopolysaccharide,LPS)诱导小鼠肠道屏障功能及微生物组成的影响。方法:选取8周龄C57BL/6J雄性小鼠48只,随机分为4组,每组12只,分别为空白对照(Ctrl)组、LPS组、EP组、EP+LPS组,Ctrl和LPS组小鼠饲喂基础日粮,EP和EP+LPS组饲喂含600 mg/kg EP的日粮,28 d后,LPS和EP+LPS组小鼠按0.5 mg/kg mb腹腔注射200μL LPS,Ctrl和EP组小鼠腹腔注射相同剂量的生理盐水。结果:EP处理4周对LPS诱导的小鼠肝脏损伤和脾脏肿大没有显著影响;EP处理能显著降低LPS诱导小鼠的血清中髓过氧化物酶(P<0.05)和二胺氧化酶(P<0.01)的含量,显著提高结肠白细胞介素(interleukin,IL)-1β的基因表达(P<0.05),显著降低结肠一氧化氮合成酶(inducible nitric oxide synthase,iNOS)的基因表达(P<0.05)和Toll样受体4的蛋白表达;在门水平上,EP处理能极显著提高LPS诱导小鼠Verrucomicrobiota的丰度(P<0.01),在属水平上,显著降低Alloprevotella、Bacteroides和unclassified_o_Bacteroidales的丰度(P<0.05),显著提高Lachnospiraceae_NK4A136_group、Anaerostipes和Akkermansia的丰度(P<0.05)。结论:EP可以预防LPS刺激引起的肠道屏障功能受损,并可通过调节TLR4信号通路相关基因的表达和肠道微生物的组成减缓小鼠的肠道屏障损伤。