Extraction of agar from Eucheuma cottonii and Gelidium amansii seaweeds with sonication pretreatment using autoclaving method

The effect of sonication pretreatment condition on Eucheuma cottonii and Gelidium amansii seaweed towards agar extraction wae studied.Four parameters were changed during sonication to investigate the effects on agar yield and quality.These parameters include the time interval,concentration ratio,frequency,and intensity.The highest amount of agar extracted from Eucheuma cottonii species could be obtained from the time interval of 30min,seaweed weight to solvent volume ratio of 1:20,the frequency of 35Hz,and the sonication power intensity of 30%.For Gelidium amansii species,the best agar yield also could be obtained from the time interval of 30 min,1:20 of seaweed weight to water volume ratio,the frequency of 35Hz,and power intensity of 30%.From the experiment,sonication pretreatment signifi cantly influenced the yield and properties of extracted agar.The sonication with autoclaved seaweed produced agar containing less sulfate content,which is an excellent chemical property for gel electrophoresis applications.The gelstrength of sonication with autoclaving for both seaweeds,Eucheuma and Gelidium species was the highest among those by sonication with direct heating,which proved that sonication pretreatment with autoclaving could enhance the physical properties of the agar.

Morphological Comparison and Composition Analysis of Wild and Farmed Eucheuma gelatinae in Hainan Province

The morphology and compositions of wild and farmed Eucheuma gelatinae in Hainan Province were compared. The results showed that wild E. gelatinae had greater frond,with more and longer branches. The main compositions of wild and farmed E. gelatinae were carbohydrates composed of dietary fiber and soluble sugars. The wild E. gelatinae had higher soluble sugar content than farmed E. gelatinae,while farmed E. gelatinae had higher dietary fiber and carrageenan yield.Both of wild and farmed E. gelatinae had advantages and disadvantages,and we could choose the best raw materials according to the actual application.

REPRODUCTIVE MORPHOLOGY OF EUCHEUMA GELATINAE (ESPER) J. AGARDH (SOLIERIACEAE, GIGARTINALES, RHODOPHYTA)

Eucheuma gelatinae (esper)J.Agardh has vegetative and reproductive features distinguishing it fromother species of Eucheuma.The occurrence of reproductive nemathecia containing carpogonial branches,auxiliary cells and post-fertilization stages including gonimoblast and pericarp initiation,fusion cell foram-tion stages and carposporophyte development are described and ilustrated for the first time for this species.

Study on Tissue Culture and Adventitious Bud Induction of Eucheuma striatum

This study aimed to investigate the aseptic treatment and disinfection of E. striatum explants and the effects of three liquid culture medium （ PES, PESI, f/2） and plant hormones on adventitious bud induction from explants. The results showed that the vast majority of explants disinfected by combined treatment exhib- ited good growth and normal color with an average mortality rate of only 9%. E. striatum explants exhibited the best growth in PES liquid medium and the survival rate reached 66.67% at 40 d after culture. Under different concentrations （0.5, 2, 5 mg/L） of 6-BA, the induction rate ofE. striatum explants was significantly higher than that in control group, but no remarkable differences were found in the induction of adventitious buds from E. striatum explants. In PES liquid medium containing 6-BA and 2,4-D, the adventitious bud induction rate was 90% and the average number of induced adventitious buds was 6.63.

海藻麒麟菜Eucheuma muricatum中的新糖脂化合物的结构测定

从海藻麒麟菜Eucheuma muricatum中分离到一个甘油糖脂化合物,经用波谱方法及化学方法确定它的化学结构,是一个新型的核糖苷核糖基甘油糖脂化合物,本文是首次报道这类糖脂化合物在自然界中的存在.

Structure and Anti-influenza A(H1N1) Virus Activity of Three Polysaccharides from Eucheuma denticulatum

Three polysaccharides(EW,EH and EA) were prepared from a red alga Eucheuma denticulatum by sequential extraction with cold water,hot water and sodium hydroxide water solution.Their monosaccharide compositions,relative molecular mass and structural characterization were determined by gas chromatography,high performance 1iquid chromatography,fourier transform infrared spectroscopy and nuclear magnetic resonance spectroscopy methods.EW was hybrid ι/κ/ν-carrageenan(70 ι/17κ/13ν-carrabiose),EH was mainly ι-carrageenan,and EA was mainly α-1,4-Glucan(88%) but mixed with small amount of ι-carrageenan(12%).The relative molecular mass of EW,EH and EA was 480,580 and 510 kDa,respectively.The anti-influenza A(H1N1) virus activity of these three polysaccharides was evaluated using the Madin-Darby canine kidney cells model.EW showed good anti-H1N1 virus activity,its IC 50 was 276.5 μg mL-1,and the inhibition rate to H1N1 virus was 52% when its concentration was 250 μg mL-1.The IC 50 of ι-carrageenan EH was 366.4 μg mL-1,whereas EA showed lower anti-H1N1 virus activity(IC 50 >430 μg mL-1).Available data obtained give positive evidence that the hybrid carrageenan EW from Eucheuma denticulatum can be used as potential anti-H1N1 virus inhibitor in future.

Molecular identification based on ITS sequences for Kappaphycus and Eucheuma cultivated in China

The systematic classification of the Eucheumatoideae is difficult because of their variable morphology and interpretation of reproductive structures. Kappaphycus and Eucheuma specimens cultivated on the Hainan and Fujian coast of China were introduced from Vietnam, the Philippines and Indonesia. Combined with morphological characteristics, all Kappaphycus and Eucheuma cultivated strains were identified by internal transcribed spacer (ITS) sequences. The phylogenetic tree was constructed using neighbor-joining and maximum likelihood methods. The results indicate that different ITS sequence lengths occurred in the different genera and species. An obvious difference in morphology could be found in the protuberance shape between Kappaphycus and Eucheuma. The protuberance in Eucheuma was thorn-like and in Kappaphycus was wartlike or papillate. Their ITS sequence lengths differed significantly in nucleotide variation rates up to 58.55%-63.90%. All nucleotide variations occurred in the ITS1 and ITS2 regions except for five nucleotide transversions in the 5.8S rDNA region. In addition, the difference was at the branches among congeneric species. Kappaphycus sp. had branches with small buds, while K. alvarezii did not have such a feature. The nucleotide variation rates varied from 7.02% to 7.48% among species; within the same species of the clades it was <1.20%. Eucheumatoideae algae cultivated in China consisted of three clades, K. alvarezii, Kappaphycus sp., and E. denticulatum. The results indicate that ITS sequence analysis was an effective way for identification of interspecies and intraspecies phylogenetic relationships and might provide a clue for molecular identification of algal Eucheumatoideae.

The potential of Eucheuma cottonii extract as a candidate for fish anesthetic agent

Red seaweed species Eucheuma cottonii was thought to have potential as an anesthetic agent because it is shown to contain compounds with bioactivity as antimicrobial,antifungal,and also anticancer.There have been no studies regarding the active ingredients of anesthetized.The objective of the study was to examine the potential of E.cottonii extract as a candidate for fish anesthetic based on toxicity,phytochemistry,and active compounds contained in the extract.The stages of research include extraction,toxicity test extracts(BSLT),phytochemical test,quantitative test compound phytochemical results,and the identification of active compounds with LC-MS.Test results showed that E.cottonii extract contains a total of phenols of 4.60±0.06 mg/GAE g which is one presentation of the active ingredient in the extract.The extract had bioactivity with LC_(50) of 221.71±5.74μg/mL.E.cottonii extract contained flavonoids compounds and saponins with a consecutive number of 24.48%and 0.22%.The results of identifying active compounds were found in several compounds that had activity asantidepressants or sedatives.E.cottonii extract can be used as a candidate for a fish anesthetic agent.

超声波辅助复合酶法提取Iota卡拉胶工艺优化

目的:优化Iota卡拉胶提取工艺,以期提高Iota卡拉胶产率。方法:采用超声波辅助复合酶技术从刺麒麟菜中提取Iota卡拉胶。通过单因素和正交试验,确定最佳复合酶(纤维素酶、半纤维素酶、木瓜蛋白酶)配比和复合酶酶解条件,并优化超声处理条件和煮胶工艺条件。结果:最佳复合酶配比为纤维素酶0.50%、半纤维素酶1.25%、木瓜蛋白酶0.20%;最佳酶解条件为酶解温度60℃,酶解pH 5.5、酶解时间2.5 h、酶解料液比1∶30 (g/mL);最佳超声处理工艺为超声功率350 W、超声时间25 min、超声温度40℃;最佳煮胶工艺为煮胶温度90℃、六偏磷酸钠(SHMP)添加量0.04%、煮胶时间3 h。结论:在最优工艺条件下,提取的Iota卡拉胶产率高,可达到47.17%。

琼枝麒麟菜多糖的分离纯化、结构表征及降血糖活性

为研究琼枝麒麟菜(Eucheuma gelatinae)多糖的结构及其粗多糖和纯化组分的降血糖活性,以超声波辅助酶法提取的琼枝麒麟菜粗多糖为原料,采用DEAE-52离子柱纯化、PMP衍生,用HPLC法测定各组分单糖组成。结果表明:琼枝麒麟菜粗多糖(EGP)和纯化组分(EGP-1、EGP-2、EGP-3)均为吡喃型硫酸多糖,主要由甘露糖(Man)、葡萄糖(Glc)、半乳糖(Gal)、木糖(Xly)和阿拉伯糖(Ara)5种单糖组成;与EGP相比,纯化多糖的蛋白质含量显著降低(P<0.05),EGP-2和EGP-3的糖醛酸和硫酸根含量显著提高(P<0.05);EGP和EGP-1有三螺旋结构,EGP-2和EGP-3无三螺旋结构;多糖的体外降血糖活性显示,4种多糖均能有效抑制α-淀粉酶和α-葡萄糖苷酶的活性,且呈剂量依赖性,其中EGP-3的降血糖效果最优。研究表明,与EGP相比,3种纯化组分的相对分子质量均有所降低,且表现出更强的降血糖活性。

无机盐对I型卡拉胶脱水工艺的影响

采用超声波辅助复合酶技术从刺麒麟菜中提取Iota卡拉胶,针对传统卡拉胶脱水方式能耗大、生产成本高等问题,采用单因素试验考察无机盐种类(CaCl_(2)、KCl、NaCl)及浓度对胶液脱水醇沉中所需酒精量、卡拉胶产率和卡拉胶理化指标及其含盐量的影响。结果表明:加入无机盐对卡拉胶产率无显著影响,3种无机盐的添加能够有效减少酒精消耗量,随CaCl_(2)和KCl添加量的增加,卡拉胶的凝胶强度显著提高,但其黏度却显著下降,而高浓度NaCl导致卡拉胶的黏度和凝胶强度显著下降。当胶液中CaCl_(2)和NaCl添加量分别为0.010%~0.035%和0.05%~0.20%时,卡拉胶的含盐量无明显变化,而向胶液中添加0.1%~0.6%KCl,卡拉胶含盐量随KCl添加量的增加而显著增加。

刺麒麟菜基本成分分析和ι-卡拉胶的提取工艺参数优化

以印尼海域刺麒麟菜(Eucheuma spinosum)为原料,分别采用烘箱法、高温灼烧法、凯式定氮法、索氏提取法对其水分、灰分、粗蛋白、粗脂肪含量进行测定,通过正交试验确定最佳提取工艺参数。结果表明,该刺麒麟菜中水分、灰分、粗蛋白、粗脂肪含量分别为12.93%,22.68%,4.19%和0.58%。最佳提取工艺参数由正交试验确定为:常温下,9%KOH处理5 h,90℃提取4 h。得到凝胶强度为59g/cm2,产率为47.6%的ι-卡拉胶产品。

海南麒麟菜省级自然保护区海水重金属含量与污染评价

调查及评价海南麒麟菜省级自然保护区海域海水的重金属污染现状。2019年5月从海南麒麟菜省级自然保护区海域采集18个站位海水样品,测定海水中重金属(铜、铅、锌、镉、铬、砷)含量,再采用单因子指数法对采集的海水污染状况进行评价。结果表明:海南麒麟菜省级自然保护区海域海水重金属含量总体较低,Cu、Pb、Zn、Cd、Cr、As平均含量均符合一类海水水质标准,部分站位Cu和Pb有超标现象,超标率分别为13.6%和9.1%,重金属单因子污染程度依次为Pb>Cu>Zn>As>Cd>Cr。海南麒麟菜省级自然保护区春季海洋环境质量状况良好。

异枝麒麟菜硫酸多糖的降解及其对尿石矿物草酸钙的抑制作用

采用过氧化氢法降解了相对分子质量约为141万±8.3万的海藻异枝麒麟菜(Eucheuma striatumSchmitz)硫酸多糖(ESPS),降解产物平均相对分子质量为4 819±440。降解后多糖的硫酸基(OSO32-)质量分数稍有下降,由16.03%降至15.20%左右。同时,用体外模拟方法研究了降解前后ESPS对草酸钙(CaOxa)晶体生长的抑制作用,降解后的ESPS明显优于未降解多糖,其诱导生成的一水草酸钙(COM)晶体尺寸进一步减小,晶体数量减少,且棱角更为圆钝。表明低分子质量ESPS更能抑制CaOxa晶体的成核和生长。

琼枝麒麟菜和异枝麒麟菜硫酸多糖及其水解产物的抑菌作用

目的 :探讨琼枝麒麟菜 (Eucheumagelatinae)和异枝麒麟菜 (Eucheumastriatum)硫酸多糖的KCl分级产物 ,以及其经HCl水解的不同程度的水解产物对大肠埃希氏菌等 8种细菌的抑菌作用 ,研究抗菌活性与样品化学组成的关系 .方法 :用肉汤稀释法测定不同样品对不同菌株的最低抑菌浓度 (MIC) ;用明胶 -BaCl2 法测定硫酸基含量 ;用红外光谱初步分析琼枝和异枝麒麟菜硫酸多糖及其水解产物化学组成的差异 .结果 :未水解的琼枝和异枝麒麟菜硫酸多糖均无抑菌活性 ;琼枝和异枝麒麟菜硫酸多糖的抑菌谱范围随着水解程度增加而增大 ;异枝麒麟菜硫酸多糖部分水解的水解产物的抑菌谱范围比琼枝麒麟菜硫酸多糖部分水解的水解产物广 .结论

4种海藻膳食纤维清除自由基的比较研究

采用羟基自由基体系、超氧阴离子自由基体系、烷基自由基引发的亚油酸氧化体系和DPPH体系对江蓠(Gracilaria)、麒麟菜(Eucheuma)、马尾藻(Sargassum)、海带(Laminaria)4种膳食纤维清除自由基的活性进行研究。结果表明,在羟基自由基体系中,江蓠、麒麟菜、马尾藻、海带4种膳食纤维的IC50分别为5.2mg/mL、5.5mg/mL、4.4mg/mL和4.1mg/mL;在超氧阴离子自由基体系中,江蓠、麒麟菜膳食纤维的IC50分别为4.8mg/mL和5.3mg/mL,而马尾藻、海带膳食纤维的最高清除率分别为36%和42%;在烷基自由基引发的亚油酸氧化体系中,江蓠、麒麟菜膳食纤维的最高清除率分别为36%和26%,马尾藻、海带膳食纤维的IC50分别为4.1mg/mL和3.5mg/mL;在DPPH体系中,江蓠、麒麟菜、马尾藻膳食纤维的最高清除率分别为31%、11%和26%,海带膳食纤维的IC50为6.2mg/mL。在各体系中,与相应的专一性阳性参照物对比,证明这4种海藻膳食纤维对自由基有一定的清除作用。

不同原料卡拉胶的物性比较研究

对菲律宾麒麟菜卡拉胶、海南沙菜卡拉胶和阳江沙菜卡拉胶的溶胶、凝胶性质从宏观和微观方面进行了比较研究 ;观测了其溶解性、粘稠性、悬浮性、微观网络结构、凝胶强度、质构和动态粘弹性 ,以探讨沙菜卡拉胶代替麒麟菜卡拉胶的可能性 .

高活性麒麟菜膳食纤维的提取

本文采用正交试验法,研究了高活性麒麟菜膳食纤维提取的碱处理和改性工艺条件。结果表明,在最佳工艺条件下提取的麒麟菜膳食纤维的产率为49.0%,膳食纤维干基含量为85.3%,钙含量为1.21%,膨胀力和持水力两项功能性指标分别达到29.5ml/g和17.5g/g。

麒麟菜的营养成分分析及评价

采用原子吸收法、比色法、索氏提取法和氨基酸自动分析仪等方法对印尼和海南两种麒麟菜的蛋白质、脂肪、氨基酸、矿物质、维生素等营养成分进行分析及评价。结果表明碳水化合物是麒麟菜的主要成分,印尼和海南麒麟菜碳水化合物含量分别为77.97%和76.99%;蛋白质含量分别为3.17%和2.23%;必需氨基酸含量高,限制性氨基酸为赖氨酸,氨基酸评分分别为91和87;脂肪含量分别为0.32%和0.31%;矿物质含量丰富,维生素含量较低。

超声辅助提取异枝麒麟菜硫酸酯多糖的工艺优化

对异枝麒麟菜硫酸酯多糖(ESSP)的超声辅助提取工艺进行研究,通过单因素试验和正交试验对该提取工艺进行优化。确定最佳工艺条件为超声时间20min、超声功率150W、料液(水)比1:90(g/mL),多糖的提取率达48.14%,所得的多糖含量96.94%,硫酸酯基含量19.66%。并与热水提取法进行比较,采用优化工艺提取的多糖提取率、多糖含量和硫酸酯基含量比热水提取法分别提高12.08%、8.07%和1.41%。两种方法所得ESSP均不含蛋白质和核酸,红外光谱显示其均含有糖的特征峰和硫酸酯基特征峰。