Polysaccharides from algae have received considerable attention owing to their ability to enhance crop tolerance to abiotic stress effectively. In this study, four oligosaccharides (EC1-EC4) of different molecular weights (11.66, 3.55, 2.21, and 1.61 kDa), respectively) enzymatically cleaved from Enteromorpha clathrata were applied to wheat seedlings (Triticum aestivum) under saline-alkali stress. Their effects on enhancing plant tolerance to salinealkali stress were investigated at 24 h and 120 h and compared in terms of alleviating oxidative stress, osmotic stress, ion toxicity, and stimulation of abscisic acid homeostasis. The application of EC3 (2.21 kDa) for 120 h reduced the malondialdehyde content by 11.0 % in leaves and 27.2 % in roots compared with those in the negative control (Na) group. The EC4 (1.61 kDa) group showed reductions of 15.4 % and 23.6 %, respectively. Treatment with EC3 increased the peroxidase enzyme activity enhancement of roots to 1051.6 U.gFw-1.min-1 compared to 887.7 gFw-1.min-1 in the Na group. Its application was the most effective in enhancing proline accumulation and synthesis. Several aquaporins were further up-regulated to better defend against osmotic stress, following EC2 treatment (3.55 kDa) treatment. In addition, the expression of several ionotropic proteins was significantly enhanced in cells treated with EC3 maintain ion homeostasis and reduce ion toxicity. Furthermore, EC3 stimulated abscisic acid (ABA) synthesis and ABA-dependent signaling to enhance saline-alkali resistance in wheat seedlings. In conclusion, the oligosaccharide with 2.21 kDa from E. clathrata represents an effective way to improve the resistance of wheat seedlings to saline-alkali stress.

Objective Sargassum fusiforme (SF), a brown algae, is a marine traditional Chinese medicine with nutritional value. However, studies on the bioactive components in SF are limited. The aim of this study is to investigate phytochemical and biological properties of SF from different geographical origins and botanical parts, as well as to explore bioactive components within SF. Methods SF from different origins and botanical parts were collected for integrated phytochemical analyses using ultra-high performance liquid chromatography-tandem quadrupole time of flight mass spectrometry (UPLC-Q-TOF-MS), mass spectral molecular networking and liquid chromatography-single quadrupole mass spectrometry (LC-MSD), etc., followed by the systematic chemical profile evaluation. Subsequently, the glycolipid metabolism regulation and anticoagulation of SF were examined. Furthermore, the overall information acquired was assembled using multivariate analysis and machine learning to discover bioactive components. Results A total of 123 compounds in SF were identified with the assistance of mass spectral molecular networking. The variations in the content of amino acids, fucoidan, alginate, phlorotannin, alkaloids, terpenoids, etc. were observed in SF from different origins and botanical parts. SF possessed the hypolipidemic, hypoglycemic and anticoagulant effects, and SF from Dongtou, Wenzhou, Zhejiang, was outstanding among origins in both phytochemical and biological evaluations. A heterogeneous information ensemble approach was adopted to discover the bioactive components in SF, namely 3-indoleacrylic acid, phlorotannin and fucoidan. Conclusion This study evaluated the phytochemical and biological properties of SF, revealed the bioactive components using heterogeneous information and provided a reference for the rational consumption and further development of SF.

Extracts of Ulva clathrata improve the salt–alkaline tolerance of plants. However, the underlying relevant mechanisms remain to be elucidated. In this study, transcriptome technology was used to explore the mechanisms underlying the protective effects of enzymatic hydrolysate of Ulva clathrate (EU) on 5-day-old wheat seedling roots under salt–alkaline stress. A total of 3,141 differentially expressed genes (DEGs) were identified. The KEGG pathway and GO enrichment analyses showed that EU enhanced abscisic acid (ABA) signal transduction in the roots. Further analysis revealed the involvement of several DEGs in amino acid metabolism and transduction of calcium signals. Following treatment with sodium tungstate, an ABA inhibitor, the activity of nitric oxide synthase (NOS) in TE group (salt solution, sodium tungstate and 0.1 mg/mL EU solution treatments) increased by 55.10

The use of sodium alginate in combination with chitosan in the treatment of wastewater containing dye and heavy metal (HM) ions has been presented in this chapter. Both alginate and chitosan are known as natural chelating polymers capable of adsorbing HM ions. In order to combine the anionic carboxylic acid groups in alginate and the cationic amine groups in chitosan, several methods have been developed to use these two natural polymers for wastewater treatment (WWT). For example, brown seaweeds containing alginate are dispersed in a solution of chitosan and made into pellets containing both alginate and chitosan. Alternatively, aqueous alginate and chitosan solutions can be added separately into two sets of wastewater samples to mix thoroughly with the wastewater before these two water samples are combined, at which point the anionic alginate and cationic chitosan precipitate with each other, resulting in the separation of the biosorbent from water, and the dye and HM ions are taken out together with the alginate/chitosan precipitate. Experimental results showed that the separation of polymeric adsorbents from wastewater was better when the alginate and chitosan were used in combination than used alone.

In order to improve the mechanical properties, nutritional value and fresh-keeping ability of conventional sodium alginate edible composite membranes, a new type of edible composite film was prepared by adding water-blocking agent carnauba wax, plasticizer glycerin, antioxidant and nutritional enhancer sodium ascorbate on a basis of traditional sodium alginate composite film. In this study, the physical, mechanical and structural properties of different film components were investigated. The results showed the components did not simply combine, but produced interaction forces which improved the stability and mechanical properties of composite film. When the amount of calcium ascorbate was 0.4%, the water vapor transmittance of the composite film reached a minimum of 0.65 g·mm/(cm2·d·kPa), and the tensile strength and elongation at break reached the maximum, which were 398.64 MPa and 17.93%, respectively. Additionally, the sodium alginate-carnauba wax film exhibited better performance on the preservation of fresh-cut apples. Compared with other composite films, the color and hardness of fresh-cut apples coated with this composite film were better maintained, and the losses of titration acid content and soluble solid content were reduced. Moreover, the weight loss rate, increase in polyphenol oxidase activity and total colony count were inhibited. All results determined that the edible film has good application value in the field of fresh-cut fruit preservation, which provides a theoretical basis for further research on edible film.

海藻是海洋植物的主体,含有海藻酸、 卡拉胶、 琼胶、 褐藻淀粉、 岩藻多糖等多糖以及氨基酸、 碘、 甘露醇、维生素、多酚、脱落酸、赤霉素、甜菜碱、多胺、吲哚乙酸、矿物质元素等种类繁多的海藻活性物质.这些对植物生长有刺激作用的海藻源生物刺激素可以通过物理、化学、生物等先进技术的应用使海藻细胞壁破碎后进行提取,浓缩后形成的海藻肥含有海藻中丰富的微量元素成分以及大量具有优良生物刺激作用的海藻源生物刺激素,成为一种集营养成分、抗生物质、天然生物刺激素于一体的特种生物肥料,在现代农业生产中有重要的应用价值.大量研究证明,含有海藻活性物质的海藻类肥料可以改善土壤的团粒结构,促进土壤中有益微生物的活性,吸附土壤中的重金属离子,具有优良的生物强化功效.

[Objective]To summarize and discuss the regulatory effects of fucoidan on different components of immune system.[Method]By referring to the literature at home and abroad,this paper summarized and refined the research content of the immunomodula-tory effect of the fucoidan.[Result]Fucoidan is a kind of polysaccharide containing fucose and sulfuric acid groups.It has a variety of biological functions and can enhance the activity of immune organs,non-specific immune system and specific immune system.[Conclu-sion]Fucoidan can improve the immune activity of human body by regulating the function of immune system.

为开发功能性含锌和含铜纤维及医用敷料在伤口护理中的应用,介绍了锌离子和铜离子的生物活性及其在伤口愈合过程中的作用,总结了国内外市场上各种含锌和含铜医用敷料及其制备方法,重点介绍了含锌和含铜的海藻酸盐纤维、壳聚糖纤维,以及通过静电纺丝、高分子材料复合加工、纳米技术等先进工艺制备的各种含锌和含铜医用敷料及其释放锌离子和铜离子的性能.指出锌离子和铜离子具有优良的抗菌及促进伤口愈合的功效,含锌和含铜医用敷料通过释放锌离子和铜离子,对创面常见的各种细菌有很强的抑菌作用,在烧伤、下肢溃疡、糖尿病足溃疡、褥疮等伤口护理中有重要的应用价值.

目的:探究褐藻膳食纤维对糖脂代谢的调节作用和防治代谢性疾病的关系。方法:以褐藻膳食纤维、糖脂代谢、肠道菌群、慢性代谢性疾病为检索词在中国知网、万方数据库、维普数据库、PubMed和Web of Science等数据库查找相关文献进行归纳整理。结果:褐藻膳食纤维通过减少糖脂摄入量,抑制糖脂的吸收,促进糖脂排泄等影响机体的糖脂消化吸收能力,调节肠道菌群的种类和数量以及影响肠道菌群代谢产物,从而改善糖脂代谢紊乱,预防其诱导的慢性代谢性疾病。结论:褐藻膳食纤维对调节糖脂代谢和肠道菌群具有重要作用,本文为褐藻膳食纤维在调整机体代谢和防治代谢性疾病方面的开发应用提供了参考。

The enzymatic degradation of seaweed polysaccharides is gaining interest for its potential in the production of functional oligosaccharides and fermentable sugars. Herein, a novel alginate lyase, AlyRm3, was cloned from a marine strain, Rhodothermus marinus DSM 4252. The AlyRm3 showed optimal activity (37,315.08 U/mg) at 70 °C and pH 8.0, with the sodium alginate used as a substrate. Noticeably, AlyRm3 was stable at 65 °C and also exhibited 30% of maximal activity at 90 °C. These results indicated that AlyRm3 is a thermophilic alginate lyase that efficiently degrades alginate at high industrial temperatures (>60 °C). The FPLC and ESI−MS analyses suggested that AlyRm3 primarily released disaccharides and trisaccharides from the alginate, polyM, and polyG in an endolytic manner. In the saccharification process of sodium alginate (0.5%, w/v), the AlyRm3 yielded numerous reducing sugars (1.73 g/L) after 2 h of reaction. These results indicated that AlyRm3 has a high enzymatic capacity for saccharifying the alginate, and could be used to saccharify the alginate biomass before the main fermentation process for biofuels. These properties make AlyRm3 a valuable candidate for both fundamental research and industrial applications.

海藻活性物质具有抗氧化、抗菌、抗病毒、抑制酶活性等多种生物活性,可以通过诱导气孔关闭、调节渗透压、清除自由基等作用机制增强植物抗低温、高温、干旱、盐渍、水淹、过量光、紫外线辐射、矿质营养亏缺及氧气缺乏等非生物胁迫的能力,还可以降低重金属、农药、臭氧、二氧化硫等造成的空气、土壤或水体污染对植物生长的危害.海藻活性物质通过刺激植物体内非特异性活性因子的产生、调节植物生长平衡等作用机制,可以诱导植物抗生物胁迫,提高植物抗病性,具有防治植物病虫害的功效,在保护植物健康方面具有独特的应用价值.

Obesity is a risk factor for many diseases. Energy intake plays an important role in the development of obesity. Studies have shown that increasing the amount of dietary fiber in diet can boost gut motility, increase satiety, and reduce energy intake. Alginate is a marine fiber extracted from the cell wall of alga. Recently, researchers have paid much attention to the role and mechanism of alginate in controlling dietary energy. In the study, mechanisms and influencing factors for dietary fiber from algae in regulation on energy production, storage and consumption were reviewed.

海藻含有丰富的多糖类物质,其中海藻酸盐、卡拉胶、琼胶等海藻源多糖具有优良的成膜特性,已经广泛应用于食品、美容护肤品、日化等众多领域.利用海藻多糖的成膜性能制备的农用地膜的生物相容性好、可生物降解,应用在农业生产中可辅助农作物有效利用太阳辐射热量、减少热能消耗、降低肥料挥发、避免营养物的淋溶和流失,还能通过生物降解产生具有促进植物生长的海藻寡糖,在农业生产中有很高的应用价值.

肥胖症是引起很多疾病的危险因素.随着生活水平的提高,膳食纤维干预与肠道菌群的调节在预防治疗肥胖的作用备受关注.本文对褐藻膳食纤维改善肥胖相关指标,重塑肠道菌群,从而预防肥胖的发生机制予以综述.

This study was aimed to explore the effects of fucoidan on iron overload and ferroptosis-induced liver injury, and the underlying mechanisms in rats exposed to alcohol. Sprague-Dawley rats were used to establish alcoholic liver injury model by intragastric administration with alcohol for 16 weeks. The results showed that fucoidan treatment reversed alcohol-induced increases in reactive oxygen species and malondialdehyde levels, and increased glutathione peroxidase and glutathione levels, thus protecting against liver damage. Long-term alcohol feeding resulted in abnormal increase of serum ferritin, liver total iron and the "free" iron levels. Fucoidan treatment reduced serum ferritin level and alleviated liver iron deposition. Fucoidan reversed the reduction of hepcidin induced by alcohol exposure and decreased divalent metal transporter 1 (DMT1) and ferroportin1 (FPN1) expressions in the duodenum. Electron microscope observation of liver tissues showed that alcohol exposure induced ferroptosis changes in the liver. However, fucoidan treatment could alleviate alcohol-induced ferroptosis via upregulating the expressions of p62, Nrf2, SLC7A11 and GPX4. The liver endogenous metabolites analysis by liquid chromatography and mass spectrometry showed that after fucoidan intervention, mineral absorption, biosynthesis of amino acids pathways and lipid metabolism were changed. Fucoidan intervention reduced the levels of oxidized glutathione and regulated the levels of phosphatidylethanolamines in liver tissues. Our data showed that fucoidan supplementation could inhibit iron load via regulating hepcidin-intestinal DMT1/FPN1 axis, alleviate the liver oxidative damage and protect hepatocytes from ferroptosis induced by long-term alcohol exposure through upregulating p62/Nrf2/SLC7A11 pathway in rats.

以不同浓度的有机型海藻肥作为平菇及大球盖菇栽培辅料.通过对比生长周期、各类酶活、食用菌子实体物质含量,发现不同食用菌、不同栽培方式最适海藻肥浓度不相同,其中添加3.0％～4.0％有机型海藻肥时效果较佳,可以使纤维素酶活性提高50.0％以上,SOD活性提高75.4％以上,过氧化氢酶活性提高89.4％以上,纤维素含量提高8.2％以上,多糖含量提高25.0％以上,蛋白质含量提高36.6％以上,但对脂肪含量影响不显著.

ZD-3印花糊料是一款以海藻酸钠为主要成分的复配糊料,主要应用在全涤面料的分散染料仿蜡印花中,得色鲜艳、手感柔软,印花均匀性好,可得到正反面得色一致的印花效果.

目的:探究平菇栽培料中海藻肥添加量及种类对平菇酶活力的影响.方法:将平菇子实体研磨,加入磷酸缓冲溶液后离心得到的上清液为酶提取液即粗酶液,将粗酶液进行四种不同的处理后,分别用紫外分光光度计测得OD值,可得到4种酶活力,从而比较出不同实验组酶活力的差别.结果:与传统栽培料相比,在100 g栽培料中加入5 g配合型海藻肥后过氧化氢酶活力提高了24.26％,纤维素酶活力提高了22.35％,加入10 g原料型海藻肥可使漆酶活力69.95％.由此可见海藻肥对平菇中多种酶活力有促进作用.

为明确海藻渣对甜椒生长及土壤改良的效果,通过盆栽试验分析不同用量海藻渣对甜椒生长、产量及土壤理化性质的影响.结果表明,与对照相比,添加不同比例海藻渣后甜椒叶片SPAD值均显著提高,根系鲜质量和根冠比均在添加量为8％时达到最大值.在海藻渣添加量为4％、6％和8％时,甜椒果横径、果纵径、单果质量和单株产量均显著高于对照,3个处理单株总产量较对照分别提高18.45％、16.19％、14.32％.随海藻渣施用量的增加,土壤碱解氮、有效磷、速效钾、有机质含量和pH值随之增加,土壤容重随之降低,土壤总孔隙度随之增加.综上所述,施用4％～8％海藻渣能有效改善酸性红壤理化性质,提高土壤肥力,促进甜椒生长,提高产量.

The aim of the study was to detect the neuroprotective activity of fucoidan in alcohol exposure and withdrawal mice and the underlying mechanisms. C57BL/6J mice were used to establish the murine model of chronic alcoholism and withdrawal over 10 weeks of alcohol exposure. After fucoidan treatment, the depression-like behaviors in mice with alcoholism were improved, and 5-hydroxytryptamine and brain derived neurotrophic factor levels were increased both in serum and brain tissues. Fucoidan treatment attenuated the increase of lipopolysaccharide induced by alcohol, and decreased tumor necrosis factor-α and interleukin-1β levels. In hippocampus fucoidan inhibited microglia cell activation, and down-regulated the levels of Toll-like receptor 4 and its downstream protein factors. In addition, fucoidan regulated the structure of gut flora and made the composition of microbiota more similar to that of the normal control mice with increased abundances of Prevotella and Alloprevotella. Oral administration of fucoidan could alleviate the depression-like behaviors of mice with alcoholism through the gut-microbiota-brain axis.