Effect of fermented Enteromopha prolifera on the growth performance,digestive enzyme activities and serum non‐specific immunity of red tilapia (Oreochromis mossambicus × Oreochromis niloticus)

This study was conducted to evaluate the effect of dietary inclusion of different levels of fermented macroalga, Enteromorpha prolifera, on the growth performance, digestive enzyme activities and serum non‐specific immunity of red tilapia (Oreochromis mossambicus × Oreochromis niloticus). Fish were fed the control diet or the five diets supplemented with fermented E. prolifera for 7 weeks (diets 1–5 containing 10, 20, 30, 40 and 50 g kg^?1 of fermented E. prolifera respectively). The results showed that the percentage weight gain and specific growth rate (SGR) improved significantly in fish fed diets 3, 4 and 5, and regression analysis showed SGR reached the maximum in fish fed diet containing 37 g kg^?1 fermented E. prolifera, while the feed conversion ratio reduced significantly in fish fed diets 2, 3, 4 and 5, and regression analysis showed it reached its minimum in fish fed diet containing 41 g kg^?1 fermented E. prolifera. The pepsin, erepsin, gastric amylase, intestinal amylase, gastric lipase and intestinal lipase activities in fish fed diets 2, 3 and 4 were higher significantly than the control, with the exception of the pepsin activity in fish fed diet 4. The serum total superoxide dismutase, lysozyme, acid phosphatase and alkaline phosphatase activities enhanced significantly in fish fed diets 3 and 4. In conclusion, fermented E. prolifera had positive effects on the growth performance, digestive enzyme activities and serum non‐specific immunity of red tilapia and the recommended dose of fermented E. prolifera is 37–41 g kg^?1 in the diet of red tilapia.     

浒苔的氨基酸和脂肪酸组成研究

用氨基酸自动分析仪和气相色谱-质谱联用（GC-MS）技术分析浒苔的氨基酸、脂肪酸组成和含量。结果表明,浒苔中含有18种氨基酸,氨基酸总量（TAA）为8.78%,人体所需的必需氨基酸（EAA）占总氨基酸的35.08%;从浒苔中鉴定出19种脂肪酸,由C12～C24脂肪酸组成,其中不饱和脂肪酸占脂肪酸总量的65.78%,以多不饱和脂肪酸为主,特别是16碳和18碳脂肪酸比较丰富,ω-3PUFA占脂肪酸总量的29.68%,绿藻的特征脂肪酸——亚麻酸（C18∶3n3）相对含量达18.70%。     

浒苔的快速干燥技术及其初步开发

研究了浒苔Enteromorpha prolifera的三级脱水分段快速干燥技术,浒苔发生期间以浒苔作为原料及时快速处理大量新鲜浒苔,以制胶后的海藻渣作为常备原料,节能减排,变废为宝.通过对浒苔成分和有害重金属砷、铅、镉和汞含量的分析表明,浒苔是一种低污染、高膳食纤维、高蛋白的新型海洋食品.同时进行了浒苔罐制产品的研发,科学合理地制定了浒苔罐头的调味料配方和杀菌工艺,为浒苔的进一步开发奠定了基础.     

浒苔多糖脱蛋白方法的研究

采用酶法和Sevag法对浒苔多糖进行脱蛋白研究。结果表明,酶法脱蛋白效果明显好于Sevag法。在木瓜蛋白酶用量3%(W/V),pH值6.5,温度50℃,酶解时间2.5h的条件下,浒苔多糖中蛋白质含量由原来13.6%降为5.90%;而Sevag法重复3次后,多糖中蛋白质含量仅降至10.6%。     

基于DNA条形码的如东海域浒苔附着鱼卵的物种鉴定

为了探明如东海域浒苔藻团中附着的大量鱼卵的产卵鱼种,利用DNA条形码技术对其进行了物种鉴定。鉴定结果表明:鱼卵、仔鱼、成鱼与沙氏下鱵鱼(Hyporhamphus sajori)COI基因片段序列之间无变异位点出现,遗传距离为0,而与其他颌针鱼目鱼类序列间差异达10.83%~20.94%,遗传距离在21.9%~26.4%之间;NJ分子系统发育分析显示鱼卵、仔鱼、成鱼与沙氏下鱵鱼聚为单系群。因此,确定该海域浒苔藻团中产卵鱼类为沙氏下鱵鱼。在此基础上探讨了浒苔藻团附着大量黏性鱼卵现象的原因及其对近海鱼类资源恢复的启示。     

浒苔和条浒苔生长及其氨氮吸收动力学特征研究

研究了浒苔(Enteromorpha prolifera)和条浒苔(Enteromorpha clathrata)在室内条件下的生长及其氨氮吸收动力学特征。结果表明:浒苔和条浒苔藻体体重日生长率分别为17.30%和16.82%;浒苔和条浒苔藻体幼苗在温度25℃和光照140μmol/(m2.s)的条件下达到最大体长日生长率,分别为78.9%和82.1%。在1~10 g/L密度范围内,浒苔和条浒苔对NH4+-N的吸收速率随密度和时间的增加而增加,当藻体密度为10 g/L时,NH4+-N浓度分别下降了86.43%和84.13%。两种浒苔对NH4+-N吸收速率与介质中NH4+-N浓度呈显著的线性关系,在NH4+-N浓度为400μmol/L时,30 min后浒苔和条浒苔的吸收速率分别为421和409μmol/(gDW.h),说明两种浒苔吸收氨氮的方式以被动扩散为主。在400μmol/L的起始浓度下,浒苔和条浒苔对NH4+-N的吸收速率随时间变化呈现3个不同阶段:在75 min内呈快速吸收阶段,75~185 min为内部NH4+-N控制的吸收阶段,250 min后为外界NH4+-N浓度控制的吸收阶段;在700 min后,...     

Isolation,Characterization and Bioactive Properties of Alkali-Extracted Polysaccharides from Enteromorpha prolifera

Four new purified polysaccharides (PAP) were isolated and purified from the Enteromorpha prolifera by alkali extraction, and further characterization was investigated. Their average molecular weights of PAP-1, PAP-2, PAP-3, and PAP-4 were estimated as 3.44 × 10⁴, 6.42 × 10⁴, 1.20 × 10⁵, and 4.82 × 10⁴ Da, respectively. The results from monosaccharide analysis indicated that PAP-1, PAP-2, PAP-3 were acidic polysaccharides and PAP-4 was a neutral polysaccharide. PAP-1 and PAP-2 mainly consist of galacturonic acid, while PAP-3 and PAP-4 mainly contained rhamnose. Congo red test showed that no triple helical structure was detected in the four polysaccharides. The antioxidant activities were investigated using 1,1-diphenyl-2-picrylhydrazyl (DPPH), Superoxide, and 2, 2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical assay. In vitro antitumor activities were evaluated by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. PAP-1 exhibited relatively stronger antioxidant activities among the four polysaccharides in a dose-dependent manner. At a concentration of 1.00 mg/mL, the antioxidant activities of PAP-1 on the DPPH radical scavenging rate, superoxide anion radical scavenging rate, and ABTS radical rate at 1.00 mg/mL were 56.40%, 54.27%, and 42.07%, respectively. They also showed no significant inhibitory activity against MGC-803, HepG2, T24, and Bel-7402 cells. These investigations of polysaccharides provide a scientific basis for the use of E. prolifera as an ingredient in functional foods and medicines.     

缘管浒苔的单性生殖

发现缘管浒苔生活史中，配子体进行单性生殖有两种方式：一种是配子体放散的配子不经结合，固着后直接发育成新个体，完成单性生殖；另一种是配子体配子囊中最后一个或几个配子不放散直接在原藻体上发育成新个体。放散出去的配子进行单性生殖时，第一次分裂分别产生顶端细胞和基部细胞，其发育呈顶基极性。两个细胞分别成为叶片和假根的祖细胞。末放散的配子在原藻体上进行单性生殖发育成叶状体，形成的新个体可聚生成簇。后一种单性生殖发育方式为首次报道。     

Observations on the effect of salinity and photon fluence rate on the induction of sporulation and rhizoid formation in the green alga Enteromorpha prolifera (Müller) J. Agardh (Chlorophyta, Ulvales)

ABSTRACT: Although most members of the genus Enteromorpha are important edible green algae, some species are also potentially economically valuable crops. Samples of E. prolifera were obtained from the Yoshino River estuary, Tokushima, Japan and cultured in laboratory conditions at 10°C, a salinity of 20 psu, under white light with 12 h light : 12 h dark cycle and at a photon fluence rate (PFR) of 40 μmol/m² per s for 30 days. In the present study, the effect of salinity and PFR on the induction of reproductive cells and rhizoid formation were investigated. Synchronous formation of swarmers by thalli was induced in excised disks of 1.2 mm diameter after 2–5 days incubation. The optimum salinity for maturation of reproductive cells was between 5.0 and 52.0 psu, and between 13.2 and 45.3 psu for swarmer release, although the lower limit for swarmer release was 5.0 psu. Maturation of reproductive cells and swarmer release required a PFR higher than 16 μmol/m² per s. The minimum PFR for swarmer release was 8 μmol/m² per s. Many rhizoids were formed between 1.6 and 52.0 psu and photon fluence rates between 8 and 320 μmol/m² per s. Rhizoids were formed in a polarized manner.     

正交试验法优化浒苔干燥工艺

[目的]研究浒苔的快速干燥方法,为浒苔的加工利用提供依据。[方法]采用L9(33)正交设计法对浒苔三级脱水干燥进行了优化选择。[结果]烘干温度对浒苔叶绿素含量的影响显著(P0.05),其次是时间和风量;浒苔三级脱水干燥的优化参数为温度60℃、风量1 500 m3/h、时间30 min。[结论]采用烫漂、压榨、回转干燥三级脱水技术,分阶段对浒苔进行脱水干燥,避免了单一脱水干燥的缺点,有效地降低了浒苔叶绿素等营养物质的损失。