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991.
本工作研究了我国人工养殖的海带叶片中褐藻糖的分布,及海带综合利用工业的废料碱凝沉物中褐藻糖胶的存在量和分离条件。海带叶片中的褐藻糖含量分布边缘比中部多,并从基部向尖部增加,即由0.3%增至1%以上。试验了用十六烷氯化吡啶法(CPC法)和乙醇沉淀法从碱凝沉物中分离褐藻糖胶的条件。两种方法的褐藻糖胶获得率分别为5.6%和4.4%(对干碱凝沉物),其中的褐藻糖含量分别为24.7%和28.7%。碱凝沉物中的褐藻糖含量为1.4~3.5%。还研究了从褐藻糖胶以酸水解制取褐藻糖的诸条件,并分离出纸层析纯的褐藻糖结晶。 相似文献
992.
Qinghui Ai Kangsen Mai Beiping Tan Wei Xu Qingyuan Duan Hongming Ma Lu Zhang 《Aquaculture (Amsterdam, Netherlands)》2006,260(1-4):255-263
A growth experiment was conducted to investigate the effects of replacement of fish meal (FM) by meat and bone meal (MBM) in diets on the growth and body composition of large yellow croaker (Pseudosciaena crocea). Six isonitrogenous (43% crude protein) and isoenergetic (20 kJ g− 1) diets replacing 0, 15, 30, 45, 60 and 75% FM protein by MBM protein were formulated. Each diet was randomly allocated to triplicate groups of fish in sea floating cages (1.0 × 1.0 × 1.5 m), and each cage was stocked with 180 fish (initial average weight of 1.88 ± 0.02 g). Fish were fed twice daily (05:00 and 17:30) to apparent satiation for 8 weeks. The water temperature ranged from 26.5 to 32.5 °C, salinity from 32 to 36‰, and dissolved oxygen content was approximately 7 mg l− 1 during the experimental period. Survival decreased with increasing dietary MBM and the survival in the fish fed the diet with 75% protein from MBM was significantly lower than other groups (P < 0.05). There were no significant differences in specific growth rate (SGR) among the fish fed the diets with 0 (the control group), 15, 30 and 45% protein from MBM. However, SGR in the fish fed the diets with 60 and 75% protein from MBM were significantly lower than other groups (P < 0.05). No significant differences in feeding rate were observed among dietary treatments. The digestibility experiment showed that the apparent digestibility coefficients (ADC) of dry matter, protein, lipid and energy of MBM were significantly lower compared with those of FM (P < 0.05). Essential amino acid index was found to be correlated positively with SGR in the present study, suggesting that essential amino acid balance was important. Body composition analysis showed that the carcass protein and essential amino acids were not significantly affected by dietary MBM. The lipid and n-3 highly unsaturated fatty acid (n-3 HUFA) in fish muscle, however, significantly decreased with increasing dietary MBM. These results showed that 45% of FM protein could be replaced by MBM protein in diets of large yellow croaker without significantly reducing growth. It was suggested that the reduced growth with higher MBM was due to lower digestibility and imbalance of essential amino acids. 相似文献
993.
994.
Protection of Procambarus clarkii against white spot syndrome virus using recombinant subunit injection vaccine expressed in Pichia pastoris 总被引:1,自引:0,他引:1
ABSTRACT: The potentiality of injection vaccine against white spot syndrome virus (WSSV) in crayfish Procambarus clarkii was investigated. WSSV envelope proteins VP19 and VP28 were expressed in yeast Pichia pastoris GS115. The purified recombinant proteins (2 µg/g of crayfish) were injected intramuscularly, and the same dose injected as a booster shot on fifth day after vaccination. The vaccinated crayfish were divided into two even groups and later challenged orally by WSSV-infected dead crayfish muscle (2 g/individual) on the third and 21st days after the booster shot. The relative percent survival (RPS) in the third-day group was the highest in VP28 (91%), followed by VP19 + VP28 (84%), and VP19 (45%). The RPS for the 21st-day group was the highest in VP28 (78%), followed by VP19 + VP28 (76%), and VP19 (17%). Development of vaccine by using recombinant proteins VP19 and VP28 expressed in yeast is feasible. 相似文献
995.
The humoral immune responses and host protection of channel catfish, Ictalurus punctatus (Rafinesque), against Ichthyophthirius multifiliis (Ich) were determined after immunization with live theronts and sonicated trophonts. Immunizations with live theronts or sonicated trophonts were carried out by both bath immersion and intraperitoneal (i.p.) injection. Cutaneous and serum immunoglobulin (Ig) levels and anti-Ich antibodies were measured 12 and 21 days post-immunization. The level of Ich infection and survival of catfish were determined after theront challenge. Cutaneous and serum anti-Ich antibodies were significantly higher (P < 0.05) in fish immunized with live theronts by immersion or i.p. injection, or with sonicated trophonts administered by i.p. injection, than in fish immunized with sonicated trophonts by immersion, with bovine serum albumin by i.p. injection, or non-immunized controls. Host protection was noted only in fish immunized with live theronts by immersion or i.p. injection or with sonicated trophonts by i.p. injection. There was a positive correlation between higher levels of anti-Ich antibodies and host survival in the immunized fish. 相似文献
996.
997.
副溶血弧菌的外膜蛋白及其抗原性研究↑(*) 总被引:10,自引:1,他引:10
本文对13株不同来源的副溶血弧菌的外膜蛋白及其抗原性进行了比较研究。13株副溶血弧菌的外膜蛋白有相似的SDS-PAGE图谱。大多数菌株有五条主要的蛋白质,其大致分子量分别为:a、69kDa;b、63kDa;c、40kDa;d、30kDa;e、28kDa。其中蛋白质b是所有菌株共有的。与吸附后的兔抗副溶血弧菌血清Western印迹法结果显示抗血清与多数副溶血弧菌菌株的外膜蛋白有一条共同的免疫反应带,其大致分子量为44kDa。 相似文献
998.
选择辽宁盘锦光合水产有限公司养殖基地为试验场所,于2002年春季4~5月进行试验。选择5个具有代表性的土池作为试验池,同时另选一土池作为对照池。研究相同N/P比值下不同施肥量对室外土池多盐水体的水化学和浮游植物群落、叶绿素a含量和初级生产力的影响,以及浮游动物对浮游植物的下行效应。共检出浮游生物42种。其中,浮游植物33种,浮游动物9种。浮游植物生物量高达288.2 mg.L-1,优势种为蛋白核小球藻(Chlorella pyrenoidesa)。叶绿素a含量为5.89~325.44μg.L-1。各池在第2次施肥后5~6天,叶绿素a含量达到高值,之后开始下降,8~9 d后恢复到原来水平。初级生产力均值为4.40 g(O2).m-2.d-1,呈低-高-低的变化,极值为1.25 g(O2).m-2.d-1和10.92 g(O2).m-2.d-1。以施N 2.0 mg.L-1、P 0.3 mg.L-1的4#池高峰期维持最长,施肥量的不同对浮游植物的生物量、种类数和种类组成影响较大。在北方地区的多盐水池塘,施氮磷混合肥能有效促进小球藻等藻类增长,达到定向培育的目的。 相似文献
999.
大口胭脂鱼 (Ictiobuscyprinellus )又名巨口牛胭鱼 ,俗称美国鲫鱼 ,原产于北美洲。 1 993年我国从美国引进并试养成功。上海市嘉定区于1 997年从浙江省引进该鱼的苗种 ,当年就养成商品鱼。 2 0 0 1年和 2 0 0 2年嘉定区望新水产良种场进行人工繁殖试验获得成功 ,分别获得鱼苗 2 4 0万尾和 92 5万尾。现将其人工繁殖技术介绍如下。一、亲鱼的培育1 .亲鱼的选择亲鱼主要从养成的商品鱼中挑选 ,选择个体大、无伤、无病、体质健壮的成鱼 ,放在专用塘中进行培育。繁殖用的亲鱼再从亲鱼培育池中挑选 ,年龄要求在 3龄以上 ,体… 相似文献
1000.
发展我国南极磷虾渔业的探讨 总被引:5,自引:1,他引:5
南极磷虾不但资源量巨大,而且营养价值高,已引起世界各国的极大关注。自60年代初期前苏联进行试捕调查以来,至今已有几十个国家对南极磷虾进行调查研究。前苏联、日本等国先后从70年代开始对南极磷虾进行商业性捕捞,已形成年捕捞量数十万t的规模。我国是海洋渔业资源不多,渔民人数多及捕捞生产能力较高,渔业技术较发达的国家。国内市场需求水产品数量很大,急切地谋求对外发展。重视发展我国的南极磷虾渔业,积极开发利用 相似文献