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微绿球藻、隐藻、颤藻的种间竞争关系 总被引：2，自引：0，他引：2
采用陈海水配制的无机培养液,添加营养盐的无机培养液和对虾养殖池水3种培养液,分别对微绿球藻(Nannochloropsis oculata)、隐藻(Dyptomonas eyosa)和颤藻(Oscillatoria sp.)进行单培养和混合培养,探讨3种微藻的增殖规律和相互关系.观测各处理组微藻的生长状况,并以Lotka-Volterra的双种竞争模型为基础,计算3种微藻在生长拐点后各取样点的竞争抑制参数.结果显示,在各处理组中,实验前期微绿球藻和隐藻对颤藻的生长都具有一定的促进作用,颤藻在混合培养组中的生物量大于单培养组,而微绿球藻和隐藻的最大生物量均出现在其单培养组.在各组生长拐点后,微绿球藻对颤藻的影响较小,隐藻对颤藻的抑制作用明显,各取样点隐藻对颤藻的竞争参数远大于微绿球藻对颤藻的竞争参数(P＜0.05);颤藻对微绿球藻有较小的抑制作用,而对隐藻的抑制作用明显,各取样点颤藻对隐藻的竞争参数均为各组的最大值.实验结果表明,3种微藻按竞争力从大到小依次为颤藻,隐藻,微绿球藻.颤藻对隐藻和微绿球藻有较强的抑制作用,而微绿球藻和隐藻之间的竞争抑制作用较弱,能够达到"共存"状态. 相似文献
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分别对采集自防城港白龙的皱瘤海鞘(Styela plicata)和北海南汅的冠瘤海鞘(Styela canopus)样品的共附生真菌Purpureocillium sp. FBZ-1和Penicillium sp. BNG-1进行研究。通过显微镜观察鉴定其形态,并通过分析生物学特征鉴定其种属。通过对两种真菌的次级代谢产物进行分离和结构鉴定,共分离鉴定28个小分子化合物,从中未发现新的化合物,主要的化合物类型是芳香胺类、生物碱类和二酮哌嗪类,分别为:lumichrome、 1,2,3,4-四氢-β-咔啉-3-羧酸、β-咔啉、环(异亮氨酸-脯氨酸)、环(亮氨酸-羟基脯氨酸)、环(色氨酸-缬氨酸)、环(亮氨酸-脯氨酸)、环(苯丙氨酸-脯氨酸)、环(异亮氨酸-丙氨酸)、环(色氨酸-亮氨酸)、苯乙胺、N-乙酰苯乙胺、吲哚乙胺、N-甲基色胺、N-(4-羟基)丁酰苯乙胺、对羟基苯乙胺、 5,7,4-三羟基异黄酮、 7,4-二羟基异黄酮、 5,7,3,4-三羟基异黄酮、邻苯二甲酸异辛酯、 2,4-N,N-dimethyl-lumichrome、 3,4-二氢-3-甲基-β-咔啉-1-酮、色氨酸、 2-羟基-3-吲哚丙酸、环(缬氨酸-脯氨酸)、环(亮氨酸-丙氨酸)、环(苯丙氨酸-5-甲基-3,4-脱氢脯氨酸)、环(色氨酸-天冬酰胺)。研究结果对利用我国丰富的海鞘及其共附生微生物资源并研究其次级代谢产物结构多样性,发现其中可能含有的结构新颖的化学物质以开发抗菌、抗病毒及抗肿瘤新药,具有十分重要的理论意义和潜在的应用价值。 相似文献
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Stefanie Anne van Bergeijk José Antonio Paullada Salmerón Ana Isabel López Pérez José Moreno José Pedro Cañavate Mercedes García‐González 《Aquaculture Research》2013,44(11):1724-1730
Rotifers, used in aquaculture as feed for early larval stages, are poor in carotenoids compared with copepods, the natural most common prey item of marine fish larvae. A minimal sufficient level of carotenoids in fish larvae may be essential for a correct development. The freshwater microalga Muriellopsis sp. has been identified as a potential source of the carotenoid lutein with possible application in aquaculture. Lutein is a potent antioxidant, with potentially beneficial effects as a carotenoid for fish larvae. This study describes the lutein enrichment of the rotifer Brachionus sp. when incubated with homogeneously dispersed suspensions of freeze‐dried, lutein‐rich Muriellopsis sp. in seawater. A short enrichment time (2 or 2.5 h) resulted in a higher lutein content of the rotifers than a long enrichment time (13.5 or 24 h). Although the concentration of lutein in enriched rotifers, 0.06–0.16 mg (g dry weight)?1 was low compared with its content in Muriellopsis sp. [about 3 mg (g dry weight)?1], it was in the range reported for natural copepod populations. Therefore, we conclude that freeze‐dried biomass of Muriellopsis sp. can be used to enrich rotifers with lutein, providing an adequate level of this carotenoid for marine fish larvae. 相似文献
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A novel disease outbreak occurred among cultured loach, Misgurnus anguillicaudatus in China. The diseased fish displayed lethargy, loss of appetite, black discolouration, anasarca and ventral skin hyperaemia. Clinical signs were observed in most of the fish examined, which consisted of discoloured liver, swollen spleen and petechial haemorrhage in the intestine and peritoneal membranes. The causative agent was found to be two species of bacteria by experimental infection, identified as Shewanella sp. and Listonella sp. The result showed that these were likely to be Shewanella putrefaciens and Listonella anguillarum respectively. Bacterial identification consisted of physiological and biochemical tests as well as 16S rRNA sequence analysis. In addition, antibiotic susceptibility testing was performed, revealing that Shewanella putrefaciens and Listonella anguillarum were susceptible to enrofloxacin, ciprofloxacin, levofloxacin, pipemidicacid and norfloxacin. This is the first report of S. putrefaciens and L. anguillarum from cultured loach. 相似文献
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一、神仙鱼的命名
神仙鱼的英文名为Angelfish(天使鱼),隶属于丽鱼科神仙鱼属,原产于南美洲亚马逊河流域,在圭亚那的鲁普努尼诺河和埃塞奎博河亦有分布.1911年被正式引进欧洲.1823年,Liech-tenstein首次将其命名为Zeus scalaris,后正式定名为Pterophyllum scalare,其同物异名为Pterophyllum eimekei . 相似文献
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Attempts were made to complete all possible interspecific hybrid crosses between Atlantic salmon (Salmo salar), rainbow trout (Salmo gairdneri), brook trout (Salvelinus fontinalis), lake trout (Salvelinus namaycush), and Arctic char (Salvelinus alpinus). Survival was appreciable only in (giving female first) lake × brook, salmon × char, brook × char and char × brook hybrids. Growth rates over a weight increment of 3–30 g averaged 2.14% wet weight/day for all species and hybrids (14.5–17.0°C — excess rations). The highest growth rate, 2.74%, was obtained with the brook (female) × char (male) hybrid and the lowest, 1.63%, in lake trout. Salmon (female) × char (male) hybrids grew faster than salmon; brook trout (female) × char (male) hybrids grew faster than brook trout. Salmo species grew no faster than Salvelinus species but became silvery and had greater salinity tolerance at a smaller size and earlier age. Intergeneric hybrids between female Salmo spp. and male Salvelinus spp. more closely resembled the female parent in processes related to smoltification (silvering and salinity tolerance). 相似文献
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Valcenir Júnior Mendes Furlan Irineu Batista Narcisa Bandarra Rogério Mendes Carlos Cardoso 《Journal Of Aquatic Food Product Technology》2019,28(5):465-477
There is an intensive search for alternative sources of bioactive molecules, including carotenoids, due to their potent antioxidant activities. Some aquatic microorganisms, such as thraustochytrids, have the ability to synthesize large amounts of carotenoids. The objective of this investigation was to study the effect of growth conditions (carbon: total nitrogen ratio and cultivation system) on the production of carotenoids by Thraustochytrium sp. and Aurantiochytrium sp. For Thraustochytrium sp. culture, carotenoid production was lowered by increasing the initial glucose concentration or continuous supply of glucose and nitrogen. For Aurantiochytrium sp. culture, restraining nitrogen supply or especially using a continuous supply of glucose and total nitrogen decreased total carotenoid productivity. The highest total carotenoid production (2.22 mg/L, w/v) was obtained after 192 h of cultivation of Thraustochytrium sp. using initial concentrations of 30 g/L glucose and 2.4 g/L total nitrogen (batch system). The highest production of astaxanthin was achieved in the fed-batch system with a C/N ratio of 6.2 for Thraustochytrium sp. and 40 for Aurantiochytrium sp. Therefore, it was found that the carotenoid profile can be changed by modifying the growth conditions, which can be useful for the food industry and biotechnological applications. 相似文献
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诺卡氏菌与假丝酵母的跨界融合及对退化养殖生态的修复 总被引：8，自引：0，他引：8
运用溶菌酶和蜗牛酶破细胞壁，PEG和Ca^2 促融的方法完成了诺卡氏菌和假丝酵母的跨界融合，得到具有亲本优势的融合细胞二株：GW01和GW02，通过菌落形态比较，抗生素抗性鉴定，耐热性和耐酸性比较，生长速率对比的分析，可确定其为真正的融合细胞，融合细胞较亲本细胞对水体和水质的适应范围更广，降解速率更快，能大幅去除养殖水体环境中的COD，NH4^ ,NO2^-,PO4^3-等，稳定pH，提高水中DO及水体生态环境中微生物和浮游生物的生物多样性，减少换水量，从而改善养殖生态环境，促进养殖生产。 相似文献
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Digestibility of the defatted microalgae Nannochloropsis sp. and Desmodesmus sp. when fed to Atlantic salmon,Salmo salar 
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下载免费PDF全文 The aim of the study was to investigate the apparent digestibility coefficient (ADC) of defatted biomass derived from microalgae Nannochloropsis sp. and Desmodesmus sp. when fed to Atlantic salmon postsmolts in seawater. Two experiments, one employing cold‐pelleted and the other employing extruded pellets, were carried out to determine the ADC of dry matter (DM), protein, ash and energy. The test feeds consisted of a fishmeal‐based reference feed and the algal biomass, at a ratio of 70:30, and yttrium oxide as the inert marker. The ADC of DM and protein in fish fed microalgae‐incorporated cold‐pelleted feeds were significantly higher for Nannochloropsis sp. compared with Desmodesmus sp. The Nannochloropsis sp. inclusion in extruded feeds also led to higher ADCs of DM and energy compared with Desmodesmus sp. The extrusion processing significantly increased the ADC of ash in both defatted microalgae biomass, as well as ADCs of DM in Nannochloropsis and protein in Desmodesmus sp. In conclusion, the microalga Nannochloropsis sp. was more digestible than Desmodesmus sp., and extrusion processing can be used as a means to improve digestibility of certain nutrients. 相似文献
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采用凯氏定氮法及索氏抽提法对拟沼螺(Assiminea sp.)的基本营养成分以及氨基酸、脂肪酸的组成进行了测定和分析,并与蓝蛤、淡水钩虾、沙蚕、卤虫、轮虫等饵料生物进行了比较。结果显示,拟沼螺的粗蛋白含量为67.76%,高于比较组的饵料生物,水分含量最低为42.57%,粗脂肪含量为10.4%,高于蓝蛤、淡水钩虾和沙蚕;拟沼螺氨基酸组成全面,富含鱼虾生长所必需的各种氨基酸,总量达58.51%,必需氨基酸相对含量为46.62%,与蓝蛤(46.17%)、卤虫(47.31%)、轮虫(45.69%)、沙蚕(49.48%)的值接近,远大于WHO/FAO推荐模式(35.38%),但略低于鸡蛋蛋白模式(48.08%)。另外,拟沼螺的呈味氨基酸总量较高,是淡水钩虾的2.5倍。根据氨基酸评分或化学评分,拟沼螺的第一限制氨基酸均为缬氨酸。分析比较必需氨基酸指数,拟沼螺的必需氨基酸组成更接近中国对虾和斑节对虾的必需氨基酸组成。拟沼螺体内脂肪酸种类齐全,不饱和脂肪酸含量为54.64%,多不饱和脂肪酸含量为27.45%,EPA(二十二碳五烯酸)含量为9.56%,DHA(二十二碳六烯酸)含量为4.46%。营养成分分析结果表明,拟沼螺氨基酸组成全面,必需氨基酸含量高,脂肪酸种类齐全,含有较多多不饱和脂肪酸,能够满足对虾生长对氨基酸、脂肪酸等各种营养物质的利用需求,在促进对虾生长、提高免疫力等方面具有许多潜在功效,是一种优质的生物饵料。 相似文献
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从三疣梭子蟹育苗场发病且大量死亡的大眼幼体中分离到优势生长的菌株SX1,人工感染试验证明,SX1对健康三疣梭子蟹大眼幼体及Ⅲ期幼蟹有较强的致病性;对菌株SX1进行了形态特征、理化特性等表型生物学特性检验,并进行了菌株SX1的16S rRNA、gyrB和rpoA 3种基因的同源性检索与系统发育学分析。结果显示,菌株SX1具有发光杆菌属的特征,且16S rRNA、gyrB和rpoA 3种基因序列均与发光杆菌具有较高的同源性,在系统发育树中与Photobacteriumganghwense聚为一个分支,自举数据值达100%。综合菌株SX1的形态特征、理化特性及3种基因的同源性检索与系统发育学分析,研究表明菌株SX1与P.ganghwense亲缘关系更近,鉴定SX1为P.ganghwense且为本次引起三疣梭子蟹大眼幼体大量死亡的病原菌。 相似文献
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采用组织切片法,对密斯特黄彩鲶的卵巢发育周期进行了观察.结果表明:根据卵巢外部形态,将整个卵巢发育过程分为Ⅵ期.依据不同时期卵母细胞发育特征,将卵母细胞的发育分为Ⅵ个时相.密斯特黄彩鲶属于分批非同步产卵类型的鱼类,卵巢具有卵巢腔.测得密斯特黄彩鲶体长16.81～19.24 cm个体的绝对繁殖力为2 232 ～3 846粒,相对体重繁殖力为25.0 ～ 40.6粒/g,繁殖力随体重和体长的增加而增加.同时,密斯特黄彩鲶的卵巢性腺指数有2个峰值,分别为(12.75±0.66)％和(10.14±0.47)％,分别出现6月和9月. 相似文献
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拟指环虫病是严重危害养殖鳗鲡(Anguilla sp.)的寄生虫病,为了寻求更为安全有效的免疫防治方法,对鳗鲡拟指环虫(Pseudodactylogyrus spp.)的结构蛋白及其免疫原性进行分析。以鳗鲡拟指环虫全虫蛋白为抗原,制备了鼠和鳗鲡抗拟指环虫免疫血清,ELISA检测效价分别为1∶51 200和1∶3 200。SDS-PAGE分析表明,虫体含有16 kD、21 kD、29 kD、37 kD、43.5 kD6、8 kD和110 kD等主要结构蛋白,其中29 kD的多肽为高丰度蛋白;Western blot证实免疫鳗和康复鳗血清均能识别25 kD、43.5 kD6、2 kD、81 kD等虫体蛋白。间接荧光抗体试验显示,个别虫体在头部、尾部有明显的荧光染色,大多数虫体中部两侧,特别是卵黄腺丰富区域,呈较强的荧光染色。 相似文献
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Two new species of myxozoans from the Japanese anglerfish, Lophius litulon, are described using myxospore morphology and small subunit rDNA sequences. Ceratomyxa anko sp. n. is a parasite of the gall bladder and had a prevalence of 57%. Mature spores of C. anko sp. n. are arcuate to crescent shaped with valves tapering to rounded tips. A prominent sutural line runs centrally between the round adjacent polar capsules containing the polar filament coiled two to three times. Spore measurements: length 10.8 (9.7-11.9) microm, width 41.9 (36.9-47.2) microm, polar capsule diameter 4.6 (4.1-5.3) microm. Ceratomyxa anko sp. n. can be distinguished from other Ceratomyxa spp. due to its spore dimensions and shape. Zschokkella lophii sp. n. is a parasite of the urinary bladder and had a prevalence of 70%. Mature spores are ellipsoidal to semicircular with bluntly pointed ends. The sutural line is curved or sinuous and the valves have no discernable surface ornamentation. Two almost spherical polar capsules are located separately in the ends of the spore, opening in almost opposite directions and contain the polar filament with five coils. Spore measurements: length 20.1 (16.8-24.0) microm, width 14.9 (12.7-16.8) microm, polar capsule diameter 5.1 (3.6-5.8) microm. Zschokkella lophii sp. n. can be distinguished from other Zschokkella spp. due to the terminal opening of the polar capsules within the spores and the site of infection within the host fish. In the phylogenetic analyses, C. anko sp. n. grouped with other members of the same genus forming a monophyly. Zschokkella lophii sp. n. forms a discrete clade with another Zschokkella sp. that infects the urinary bladder of marine fish. This grouping forms a sister clade to one containing members of the genus Parvicapsula, all of which are parasites of the urinary system in marine fish. 相似文献
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乳酸杆菌L1对致病弧菌的抑制作用 总被引：7，自引：0，他引：7
以致病弧菌T1、T2为检测菌,采用平板抑菌圈检测法,研究乳酸杆菌L1及其代谢产物的抑菌能力。结果表明:L1发酵上清液对两种弧菌的抑制效果和发酵液对弧菌的抑菌作用相似,即对弧菌T1的抑制作用强于T2;L1 发酵液对弧菌T1、T2的抑制能力强于上清液,表明乳酸杆菌及其代谢物质对弧菌具有协同抑制作用;L1的发酵液经3倍稀释仍对弧菌T1有抑制作用;乳酸杆菌L1生长不同时期的代谢产物对弧菌的抑菌活性不同,代谢产物的抑菌能力在衰退期>稳定期>生长期;L1的发酵液经沸水浴处理15 min其抑菌活性不变,表明抑菌代谢物质具有较好的耐热性。 相似文献