褐藻酸降解菌感染对海带抗氧化酶活性的影响

利用生物化学的方法，研究了海带被褐藻酸降解菌感染过程中的抗氧化酶活性的变化。结果表明，⑴在褐藻酸降解菌感染的初期，海带细胞内超氧化物岐化酶（SOD）和过氧化氢酶（CAT）的活性急剧升高，随着感染的进行，二者的活性逐渐下降。⑵抗坏血酸过氧化物酶（APX)的活性在感染的初期变化不明显，而在感染的后期活性有所增加。⑶在整个感染的过程中，谷胱甘肽过氧化物酶（GPX）的活性的变化无规律性，没有表现出明显的升降变化。说明这四种酶在海带抵抗褐藻酸降解菌感染的过程中所起作用大小和作用的时期有所差异。     

褐藻酸降解菌引起海带内皮层细胞储藏颗粒变化的初步研究

实验对正常海带用褐藻酸降解菌进行了人工感染，经培养使其产生烂斑，通过组织显微切片进行比较观察，发现褐藻酸降解菌首先侵入内皮层，然后再逐渐侵入到外皮层、髓部，最终导致海带病烂。切片中发现在侵染海带切片内皮层的细胞中，有大量储藏颗粒，形成椭圆或圆形。其直径范围在1．5－4．0μm之间，平均直径为2．7μm。该颗粒主要存在内皮层，从其产生到消亡的过程分析，与褐藻酸降解菌的侵入有关，并作为营养起到促进菌增殖的作用。     

褐藻酸降解菌感染下海带活性氧产生的研究

以海带为材料，选用5株感染能力较强的褐藻酸降解菌作为致病菌，研究了活性氧（ROS）在海带抗褐藻酸降解菌感染中的产生及其作用。结果表明：（1）海带在褐藻酸降解菌感染下活性氧的产生具有普遍性。（2）活性氧的大量产生只发生在褐藻酸降解菌感染的早期阶段，随着感染时间的不断延长，活性氧的产生速率逐渐降低。说明活性氧的产生是海带在褐藻酸降解感染早期启动的反应特征之一。     

褐藻酸降解菌对海带配子体克隆的作用及其药物防治研究

通过回染实验，确认褐藻酸降解菌是海带配子体克隆病害的主要致病菌；观察了对其海带配子体克隆细胞侵染的现象，并研究了抗生素对海带配子体克隆细胞和褐藻酸降解菌的作用，发现0．5－100mg/L青霉素对配子体克隆细胞的生长有一定促进作用，实验范围内各浓度青霉素对褐藻酸降解菌均有较好的抑菌效果，且抑菌效果随浓度的提高而加强。其中100mg/L青霉素10d内可将褐藻酸降解菌浓度降低到初始浓度的1／20以下，可作为海带配子体克隆保存中有效的抑菌药物。     

海带对褐藻酸降解菌的抗性与其抗氧化能力的相关性分析

采用生物化学的方法测试 2个品系的海带 (Laminariajaponica)对褐藻酸降解菌抗性的差异性 ,并对其抗氧化能力进行研究 ,旨为海带烂病的防治提供生物学基础依据。结果表明 ,1)海带荣城 1号对褐藻酸降解菌的抗性远高于海带 90 1;2 )海带荣城 1号细胞内 2种抗氧化酶 -超氧化物歧化酶 (SOD)和过氧化物酶 (POD)的活性明显高于海带 90 1;而另一种抗氧化酶—过氧化氢酶 (CAT)的活性与海带 90 1相比没有明显的差别 ;3 )海带荣城 1号的脂溶性抗氧化能力同样明显高于海带 90 1。说明海带的抗氧化能力与其对褐藻酸降解菌的抗性有一定的相关性。     

褐藻酸降解茵诱发海带病烂的组织细胞学观察

用褐藻酸降解菌对海带进行人为感染,经培养使其产生烂斑,通过组织显微切片观察表明1、褐藻酸降解菌首先侵入内皮层,然后再逐渐侵入到外皮层、髓部和表皮,最终导致海带病烂.2、感染后内皮层伤害最重,其次是外皮层和髓部,表皮的伤害最轻.3、浸染海带内皮层的细胞中,有大量颗粒状储藏物质,其直径范围在1.5～4.0μm之间,平均直径为2.7 μm.形状为椭圆或圆形.     

活性氧在海带抗褐藻酸降解菌感染中不同时期的抗氧化能力

以海带为材料,研究了活性氧(ROS)在褐藻酸降解菌感染中的产生及其作用.结果表明①褐藻酸降解菌感染引起海带活性氧的大量产生,且海带No.1活性氧的产生速率始终明显大于海带901(P<0.05).②在褐藻酸降解菌感染的早期阶段,海带维持着较高的抗氧化能力和对褐藻酸降解菌感染较高的抗性,而且海带的抗感染能力与活性氧产生速率呈一定的正相关性;2个品系相比,海带No.1的抗性又明显大于海带901(P<0.01).③在褐藻酸降解菌感染的后期,海带的抗氧化能力显著降低,膜脂过氧化和脱酯化伤害作用加剧,同时对褐藻酸降解菌感染的抗性显著降低,海带的抗感染能力与活性氧产生速率呈一定的负相关性,其中海带 No.1活性氧的产生速率、膜脂过氧化作用和脱酯化作用都远远高于海带901;相反,海带No.1对褐藻酸降解菌的抗性明显低于海带901(P<0.05).指示在感染的早期阶段,活性氧的产生在海带抵抗褐藻酸降解菌的感染中起着重要作用;而在后期阶段,活性氧的产生又大大降低了海带对褐藻酸降解菌感染的抗性.海带在感染的早期维持较高水平的抗氧化能力,而在感染的后期抗氧化能力显著下降是活性氧表现出双重作用的重要原因之一.     

皱纹盘鲍淀粉酶和褐藻酸酶的研究

利用分光光度计比色法测定了２～３ｃｍ的皱纹盘鲍（ＨａｌｉｏｔｉｓｄｉｓｃｕｓｈａｎｎａｉＩｎｏ）的淀粉酶和褐藻酸酶的最适温度和最适ｐＨ以及１１种金属离子对其的影响。结果表明：最适温度分别为３０℃、３５℃,最适ｐＨ分别为６．２４、７．１９,在最适温度下的活化能分别为５．０３×１０４Ｊ／ｍｏｌ和１．３３×１０４Ｊ／ｍｏｌ;皱纹盘鲍的三种主要消化酶的活性依次为：褐藻酸酶＞蛋白酶＞淀粉酶。Ｃｕ２＋、Ｈｇ２＋、Ａｇ＋、Ｐｂ２＋对淀粉酶活性具有显著的抑制作用,其他离子则具有促进作用,其中又以Ｍｎ２＋、Ｂａ２＋、Ｃａ２＋三种金属离子尤为突出,其促进作用比对照组高一倍以上。而对褐藻酸酶,Ｚｎ２＋、Ａｇ＋、Ｈｇ２＋、Ｌｉ２＋、Ｂａ２＋具显著的抑制作用,其他离子则没有作用。     

磁性壳聚糖微球固定化褐藻酸酶的研究

利用反相悬浮交联法制备磁性壳聚糖微球(magnetic chitosan microspheres, M-CS),并对褐藻酸酶进行固定化研究.结果表明,M-CS呈规则的圆球形,具有较好的磁响应性,可稳定地保存在弱酸和弱碱中.其弱碱交换量随着戊二醛用量的增加而减少,悬挂醛基则相应地增加.M-CS对褐藻酸酶的吸附动力学实验表明,M-CS容易吸附褐藻酸酶,但吸附的酶量受载体与酶的比例、溶液的离子浓度、戊二醛的用量、溶液pH的影响明显,而温度对吸附的酶量的影响则相对较弱.酶学性质研究表明,相对于游离的褐藻酸酶,固定化酶的最适温度略有升高,可明显改善其热稳定性和酸碱稳定性,与底物的亲和力也有所增强.     

九孔鲍褐藻酸酶降解褐藻胶的反应条件与酶解产物的分析

以九孔鲍(Haliotis diversicoloeaquatilis)为原料制备一定纯度的褐藻酸酶,并对影响其降解褐藻胶的条件和产物的性质进行分析。该酶的最适温度和pH分别为45℃和7.0;与磷酸盐缓冲液相比,其在Tris-HCl缓冲液中与底物的亲和力相对较高。动力学曲线表明酶解反应主要发生在1 h之内,在2 h之内达到平衡,酶的剂量和底物的浓度对该平衡起到一定的影响作用。反应2 h之后,添加同数量的酶或者底物发现,产物的反馈抑制只是反应达到平衡的一个影响因素,而酶的变性失活也起到了重要的作用。金属离子对酶的活性具有明显的影响,Co2 、Mg2 对酶的活性具有较强的促进作用,而Cu2 、Ag 和Zn2 则具有较强的抑制作用。产物特性黏度的变化主要是在1 h内,2 h后基本不再改变。1HNMR图谱分析发现随着聚甘露糖片段,特别是M-M二聚体的降解,MG二聚体、GGM和MGM三聚体的量相应增多,表明该酶属于甘露糖裂解酶(EC 4.2.2.3)。     

海带夹苗钳机械结构设计

很多沿海城市海带栽培采用人工操作,工作强度很大。传统海带夹苗设备进苗率低,夹苗绳的使用寿命较短。鉴于此,对海带夹苗机的传动部分做了改进。首先介绍了海带夹苗机设计方案选择依据,其次对海带夹苗机典型机械结构进行改进,最后通过实验对比确定了海带夹苗机破扣的最佳参数。结果表明:连杆、凸轮机构合理融合在海带夹苗钳的协调动作中,同时完成"夹紧—扭松—靠拢成孔"3个动作,实现了海带苗绳"夹紧—破扣—插苗"的自动化;通过实验确定了海带苗绳装夹长度为60 mm,扭转5°~10°时夹苗所需的扭力小,成孔容易。结论:改进后的海带夹苗钳短时间内即可完成海带苗装夹动作,可以为海产植物类夹苗装置的开发和应用提供参考,有较好的开发前景。     

海带收获转运装置设计

为实现海带收获转运机械化,减轻海带收获人员的作业强度,通过改进现有海带养殖筏架模式,将海带苗绳首尾依次连接成串,便于海带机械化收获转运,在此基础上设计并试制回转伸缩齿爪式收获转运试验装置。采用单元数值算法对海带收获过程中成串海带苗绳张力及拖拽力进行计算与分析,对照分析不同苗绳拖拽角度对转运装置运行状态的影响。计算分析和台架试验结果显示:海带收获转运装置拖拽附着养成海带苗绳结合点张力为1290 N,当拖拽海带苗绳起吊角≤15°时,伸缩齿爪无法挑起苗绳,易发生脱绳现象;当拖拽海带苗绳起吊角>15°时,伸缩齿爪可依次挑起海带苗绳,海带能够顺利经过转运装置,达到海带收获转运的目的;回转伸缩齿爪式收获转运装置台架试验运行情况良好,齿爪顺序伸缩机构可有效解决收获转运过程中海带缠绕齿爪的关键问题。液压系统设计采用叠加式液控单向阀,可解决油管泄漏吊臂快速下降的问题,提高系统的安全性。试验研究表明,回转伸缩齿爪式收获转运技术是可行的,可为海上试验打下扎实的基础。     

Harvesting machine for kelp culture in floating raft

Kelp is not only a kind of food of sea vegetable for human, but also widely used as raw materials in processing food, chemical engineering, pharmaceutical and cosmetic industries. In China kelp is generally planted on floating raft by using horizontal kelp rope cultivation method and often harvested manually. Harvesting kelp by hand is a difficult process with low production efficiency and high labor intensity. In this paper, a harvesting machine was developed for floating raft culture of kelp. It consists of mainly two locomotion modules, a collection/transmission module and a power module. The structure and working mechanism of this machine was presented and analyzed in detail. The tests of experiments were conducted as well with the developed machine. The manual harvest efficiency is 16.7%; however the mechanized harvest efficiency average value is 35.8%. The harvest time could be reduced by half if the company takes the same people to work. It is proven that the design of the machine is feasible.     

Hydrodynamic characteristics of a full-scale kelp model for aquaculture applications

Hydrodynamic characteristics are needed to optimize the design of kelp aquaculture systems. To support this need, the objective of this study was to resolve both the normal and tangential drag forces acting on a dense aggregate of kelp blades using full-scale physical model tests. The physical model was designed to match the exposed length, individual blade flexural rigidity, the number of blades per unit width, the mass/length of biomass, and the aggregate mass density of kelp cultured at the University of New England experimental aquaculture lease site in Saco Bay, Maine USA. Tow tests were conducted at the United States Naval Academy in a tank with the dimensions of 116m × 7.9m × 4.9 m. The large tank size enabled the use of the full-scale physical model, minimizing dynamic similarity issues. In a series of tests, the model was towed in orientations both aligned and perpendicular to the tow direction. Horizontal and vertical reaction forces were measured for five tow speeds, along with the deflection of the dense kelp aggregate. With these datasets and the wet weight biomass per length of the model, normal and tangential drag forces were calculated. Drag components were processed into corresponding normal and tangential drag-area values. The drag-area representation was chosen since reference areas were ambiguous for both the actual kelp and model. At the higher speeds, the total horizontal drag in the aligned configuration were slightly lower than for the perpendicular orientation. Normal drag-areas as a function of tow speed ranged from 2.36 m²/m to 1.39 m²/m for the aligned case and from 2.49 to 1.88 m²/m for the perpendicular case. Tangential drag-areas as a function of tow speed ranged from 0.264 m²/m to 0.0325 m²/m for the aligned case and from 0.213 to 0.0415 m²/m for the perpendicular case. A transition from a bluff body to a streamlined body occurred as the tow speeds increased. To investigate this transition, horizontal components of the normal and tangential drag forces were reconstructed with the results of the tow tests. The reconstructed forces were obtained using a force balance system of equations with drag-area values for tow speeds less than 0.25 m/s extrapolated from the experimental datasets. For both aligned and perpendicular orientations, the model-aggregate reconfigured at a threshold of 0.25 m/s. We defined the threshold for reconfiguration as the tow speed at which the horizontal component of tangential drag equaled or exceeded the horizontal component of the normal drag. The drag-area results from this study can be incorporated into a dynamic fluid-structure interaction model representing kelp aggregates as a finite element beam prescribed with in-situ values of length, volume, mass density and flexural-rigidity of kelp material.     

益生菌制剂在水产养殖中的应用

长期使用抗生素和其他化学药物防治养殖病害已引发了一系列环境和社会问题[1,2 ] 。近年来 ,人们开始尝试在养殖水体中施用益生菌 (Ｐｒｏｂｉｏｔｉｃｓ)来改善养殖生态环境 ,提高养殖动物的免疫力 ,抑制病原微生物 ,从而减少疾病的发生。在欧美、日本以及印度尼西亚、泰国等国家的水产养殖业中 ,益生菌制剂得到日益广泛的应用 ,并已创造了巨大的经济效益 ,有望成为未来水产养殖动物病害防治的一个新方向。本文对近几年来国内外益生菌制剂在水产养殖中的应用状况予以系统介绍并对今后的发展趋势进行阐述。1　益生菌浅析1974年Ｐａｒｋｅｒ…     

Research on integrated specialized ship for kelp harvesting,classifying and grading

In this study, an integrated specialized ship for kelp harvesting, classifying, and grading is developed in order to (1) solve issues in mechanization of traditional raft-frame-based kelp farming, (2) reduce labor intensity and labor input in the kelp harvesting process, and (3) accelerate the industry by upgrading and transforming the current system of kelp farming. In addition, the influence of sea conditions on operation of this ship is evaluated and analyzed using three-dimensional modeling and simulation. The ship is designed according to the state-of-the-art raft-frame structure. Based on man-machine coordination, a duplicated raft-frame structure is adopted, such that the processes of harvesting, classifying, grading and packing can be integrated. This shortens the process flow, improves on efficiency, and addresses the non-standard and irregularity issues of traditional rafts that are trussed by hand. In the meantime, the impacts of sea waves and turbulence on the mechanized kelp harvesting are also minimized. Furthermore, the combination of theoretical calculation and experimental verification is implemented successfully. Through the research and development of this integrated specialized ship for kelp harvesting and grading, the "bottleneck" can be overcome, which is mainly caused by the inefficiency of the current kelp industry and the contradictions in labor force structure.     

大型海藻多糖的制备及应用研究

海藻多糖是大型海藻重要的组成成分,其生物活性是近年来研究的热点和重点。本文综述了近年来海藻多糖的水提、醇提、酸碱提、酶提、超声波辅助提取和微波辅助提取等6种方法,比较了不同制备方法的适用性及优缺点,详述了海藻多糖的免疫调节、抗肿瘤、抗病毒、降血糖、降血脂和抗氧化等生物活性及作用机理,介绍了海藻多糖在生物医药、食品以及化妆品领域的应用情况,展望了海藻多糖未来的研究重点,以期为海藻高值化开发利用研究提供一定的参考。     

出口脱水板状海带片的研制

研究了干海带加工出口脱水板状海带片的工艺和技术。采用干海带５倍量的自来水，加进适时软化剂及表面处理剂，浸泡１０ｍｉｎ，可以得很好的软化效果，且营养成份损失较少。     

海带晾晒干燥特性及干燥模型研究

为探究新鲜海带在晾晒情况下海带总多糖、甘露醇和褐藻胶含量的变化,掌握其晾晒干燥特性并建立可准确预测干燥进程的干燥模型,以湿基含水率、干燥速率、干燥时间为指标,海带湿基含水率达到18％以下作为干燥终点,分析山东荣成海域海带在光照度大于30000 Lx且相对湿度小于70％情况下晾晒,湿基含水率以及海带总多糖、甘露醇和褐藻胶...     

WSSV口服卵黄抗体的制备及在螯虾中的应用

将提纯的WSSV接种于蛋鸡后获得了高效价的IgY(卵黄抗体),与一定比例的保护剂混合后,瞬间喷雾干燥制成干粉其效价基本维持不变。在以螯虾为实验模型的攻毒及治疗试验结果表明:饲料中0.1%的IgY含量能在一定程度上延缓螯虾死亡时间,而0.2%的IgY含量则能够使螯虾的最终死亡率从100%降至30%左右。这表明WSSV特异性IgY制剂是安全有效的抗WSSV感染的的新型生物制剂。