马尾藻提取液对侧耳菌丝营养及生殖生长的影响

[目的]探究马尾藻提取液对侧耳生长的影响,为其开发利用提供依据。[方法]研究不同浓度马尾藻提取液对1株亚光1号侧耳菌丝生长及生殖生长的影响。[结果]稀释1 000倍的马尾藻提取液对亚光1号的菌丝生长有显著促进作用,菌丝生长速率达10.49 mm/d;对亚光1号的产量有显著促进作用,产量提高16.0%。[结论]稀释1 000倍的马尾藻提取液对供试菌株的营养生长及生殖生长都有显著的促进作用,能达到增产的效果。     

Structural and Rheological Characteristics of Alginate from Sargassum cristaefolium Extracted by Twin Screw Extruder

This study aimed to investigate the effects of process extrusion on the characteristics of Sargassum cristaefolium sodium alginate (SCSA) extracted using twin-screw extruder. Box-Behnken Design (BBD) from response surface methodology (RSM) was established to understand the effects of temperature, screw speed, and pH on the multiple-responses of alginate characteristics including intrinsic viscosity, yield, and molecular weight. The results revealed that temperature, screw speed, and pH significantly affected (P < .05) all responses. The optimum extraction condition was found at temperature of 58.18°C, screw speed of 77.99 rpm, and pH 10.11. At this condition, the response of residence time distribution was 7.07 ± 0.029 min, yield of 34.01 ± 0.12%, intrinsic viscosity of 460.13 ± 14.75 mL/g, and molecular weight of 217.94 ± 7.14 × 10³ g/mol. This alginate had mannuronic acid to guluronic acid (M/G) ratio of 0.28, and the L-guluronic acid block was 0.78, which was higher than the D-mannuronic acid block. Rheological characterization of SCSA in aqueous solution was shear-thinning pseudoplastic, and alginate gel in 1 M CaCl₂ was more elastic than liquid.     

Damage to the Membrane Permeability and Cell Death of Vibrio parahaemolyticus Caused by Phlorotannins with Low Molecular Weight from Sargassum thunbergii

ABSTRACT

To understand the mode of action of low molecular weight phlorotannins (LMPs) from Sargassum thunbergii against Vibrio parahaemolyticus, effects of LMPs on the growth curve and the content changes of some substances in culture media were investigated, and those on morphological and ultramicrostructure were also observed by scanning electron microscope and transmission electron microscopy. The results showed that LMPs inhibited thalli growth at logarithmic phase and damaged the cell membrane and cell wall of tested bacteria which led to the leakage of cytoplasm and the deconstruction of membrane permeability. The present study indicates that LMPs as natural products in seaweeds deserve further investigation for food safety control and aquacultural drugs.     

大连沿海3种大型速生海藻的营养组成分析

对采自大连沿海的角叉菜（Ｃｈｏｎｄｒｕｓ ｏｃｅｌｌａｔｕｓ）、孔石莼（Ｕｌｖａ ｐｅｒｔｕｓａ）、海黍子（Ｓａｒｇａｓｓｕｍ ｋｊｅｌｌｍａｎｉａｎｕｍ）的营养组成进行分析。结果表明,这３种大型速生海藻的营养均衡齐全,均为高蛋白、低脂肪、低热量食品,并富含矿物质、人体必需的微量元素、氨基酸和脂肪酸。     

金潮原因种铜藻外源无机碳利用特征初步研究

为揭示铜藻(Sargassum horneri)对无机碳利用的基本特性及铜藻在漂浮过程中生物量迅速累积并最终发展为金潮的生理生态学机理,以我国近海金潮原因种铜藻为研究对象,在不同pH (6.5、8.0和9.5)条件下研究了添加TRIS缓冲剂、碳酸酐酶抑制剂(AZ、EZ)和阴离子交换蛋白抑制剂(DIDS)后藻体的固碳速率、光合作用-无机碳响应曲线(P-C曲线)及pH漂移曲线。结果显示,TRIS缓冲剂对铜藻的固碳速率无显著影响(P>0.05),而3种抑制剂均显著(P<0. 05)抑制铜藻的固碳速率且抑制效率从大至小依次为DIDS> EZ>AZ。藻体的固碳速率随着外源无机碳浓度的增加而增加,并渐趋饱和。此外,藻体的最大固碳速率(V_max)随着pH的升高而降低,而半饱和常数(K_0.5)则随着pH的升高而升高,藻体的pH补偿点为9.0左右。结果表明,铜藻既可以利用海水中的CO_2也可以利用HCO_3^-进行光合作用;并且铜藻对HCO_3^-的吸收存在通过阴离子交换蛋白直接转运吸收和利用碳酸酐酶将HCO_3^-转化为CO_2后再吸收两种方式。对HCO_3^-的高效吸收利用能力可能是铜藻保证维持较高光合作用、快速积累生物量并最终演变为金潮的重要因素之一。     

硇洲马尾藻人工育苗常见敌害生物及防治初探

本文调查了硇洲马尾藻人工育苗期间的主要敌害生物,并初步探讨了不同物理方法和化学药剂对其敌害生物的清除效果,旨在为人工育苗栽培提供基础资料。调查发现硅藻、刚毛藻、石莼、浒苔等附生藻类对硇洲马尾藻生长影响较大,蓝子鱼、麦秆虫和藻钩虾的摄食是硇洲马尾藻幼苗海区培育的主要危害。苗帘用5%硫酸铵药浴5min可抑制刚毛藻的生长,以2%柠檬酸药浴5min、0.3%醋酸药浴3min、3%硝酸铵药浴5min等均可药杀石莼、浒苔等附生绿藻,用640mg/L敌百虫浸泡10min可杀灭藻钩虾。     

羊栖菜马尾藻光合作用与水温、光强的关系

羊栖菜马尾藻在不同水温、光强下，光合作用各有其明显的规律性，有适宜的水温和光强范围。光合作用的适宜水温约为１５－２５℃，而以２０℃为最适水温。光饱和产争光合速度随水温２０，１５，２５，１０℃依次降低。根据测定结果，本文对其在羊栖菜马尾藻生产上的合理应用，促使养殖技术和产量的提高，进行了探讨。     

2种大型海藻养殖对水体DIC含量的影响

为了解大型海藻养殖对水体溶解无机碳(DIC)含量的影响,明确其在光照、黑暗及光暗交替条件下水体DIC含量的变化过程,将取自温州洞头近海养殖的鼠尾藻、羊栖菜在实验室内进行养殖试验,设置光照、黑暗、光暗交替处理,测定了养殖水体DIC含量,并对DIC变化速率进行了分析。结果显示：在光照条件下,鼠尾藻DIC的消耗速率比羊栖菜高(P<0.05)。在黑暗条件下,鼠尾藻DIC释放速率比羊栖菜高(P<0.05)。随着光暗交替周期的延长,鼠尾藻、羊栖菜DIC的消耗速率均是先升后降,鼠尾藻DIC消耗速率比羊栖菜高。近海海藻养殖时随着光暗环境的交替进行,将发生光合作用消耗DIC、暗呼吸释放DIC的转换。总体而言,海藻养殖最终降低了水体DIC含量,能够促进大气CO₂向海水转移,而且随养殖大型海藻的收获,形成一个“可移出的碳汇”,大力发展大型海藻养殖具有重要的碳汇生态意义。     

大陈浅海区羊栖菜软筏式栽培技术初步研究

选用本地自然海区羊栖菜苗种,采用软筏式进行羊栖菜栽培试验,结果表明：羊栖菜生长与海区水温有很大关系,前期生长慢,后期生长快,最快是在5月,4月次之,12月最慢。从2005年9月28日起,历时7个月的养殖,至2006年5月初羊栖菜开始上市,至6月底全部收成,2×10^4 m^2养殖面积共收获羊栖菜（干菜）1.366×10^4 kg,产值20.763 2×10^4元,纯收入9.663 2×10^4元,创效益每667 m^23 221.06元。