共查询到20条相似文献，搜索用时 31 毫秒
1.
研究了海洋链霉菌分离株M095的基因转移系统。利用属间接合转移将具有oriT的大肠杆菌-链霉菌穿梭质粒pIJ8600转入EscherichiacoliET12567(pUZ8002)中,获得供体菌。将供体菌与预萌发的菌株M095的孢子进行接合转移,将质粒pIJ8600转入菌株M095中,其转化率为1.99×10-4个接合转化子/受体。Southern杂交证明质粒pIJ8600已经整合到菌株M095的染色体上。同时,将来自Spirulinamaxima(Cyanophyta)的别藻蓝蛋白基因(apc)克隆在质粒pIJ8600的XbaI和BglII位点,产生质粒pAPIJ。用接合转移法将质粒pAPIJ转入菌株M095。通过SDS-PAGE分析,得到2个大小为22ku和17ku的蛋白,分别相对应于别藻蓝蛋白的α和β亚基。这些结果进一步证明菌株M095的遗传转化体系已经成功建立起来,这将为其他海洋放线菌遗传转化工作的研究奠定基础。 相似文献
2.
The food consumption and ecological conversion efficiency of a species marine pelagic andsmall size fish, Hyporhamphus sajori, were determined by using in situ stomach content method presented by Eggers. The results showed that: (1) the fish was taken in food all day, so empty-stomach rate was very low, taking up about 4.5% of the total determined fish number. However, the fish still has significant daily feeding rhythm. A feeding peak was found 0:00 o'clock at night, but feeding level was always high in the daytime; (2) relationship between instantaneous food content in stomach and corresponding time could be described as S_t = a ·e ~(-b ·t). There was not significant difference of instantaneous gastric evacuation rate between two determinations, with average value being 0.13 × 10~(-2)g/ (g·d) (wet weight); (3) the daily food consumption tended to change in irregular waving form, with average value being (10.16×l0~(-2)±1.19×l0~(-2) g/ (g·d) (wet weight) or (55.56 × 10~(-2) ±6.51 × 10~(-2) kJ/ 相似文献
3.
综合考虑酶混合液处理时间和初始细胞密度两个因素,选取终浓度为4%半纤维素酶和2%崩溃酶的酶混合液对一株海洋经济微藻——微拟球藻(Nannochloropsis oculata)进行原生质体的制备与再生,Calcofluor White染料染色可在荧光显微镜下观察到完整的原生质体细胞。实验结果表明:同一初始密度藻细胞酶处理1～3 h制备率较高;酶处理相同时间较高初始密度(2×107～3×107cells/mL)的藻细胞制备率较高,并且原生质体在再生培养基上可再生,生长趋势与野生型细胞一致。考虑到酶处理时间过长或者密度过大会对原生质体的再生产生影响,本实验选择最适酶处理时间为1h,初始细胞密度为2×107cells/mL。 相似文献
4.
The impacts of Prorocentrum donghaiense Lu and Alexandrium catenella Balech, causative species of the large-scale HAB in the East China Sea, were studied under laboratory conditions. According to bloom densities, the effects of monoculture and mixture of the two species were examined on the egg-hatching success of Argopecten irradians Lamarck, and the population growth of Brachionus plicatilis Müller and Moina mongolica Daday. The results showed that monoculture of A. catenella had a significant inhibition on the egg hatching success of A. irradians, and the population growth of B. plicatilis and M. mongolica. The median effective densities (ED_50) inhibiting the egg hatching success of A. irradians for 24 h and the population growth of B. plicatilis and M. mongolica for 96 h were 800, 630, and 2 400 cells/cm3, respectively. Monoculture of P. donghaiense has no such inhibitory effect on the egg hatching success of A. irradians; P. donghaiense at lower suitable densities could sustain the population growth of B. plicatilis (1×104~3×104cells/cm3) and M. mongolica (2×104~5×104cells/cm3); P. donghaiense at higher densities had significantly adverse effect on the population growth of B. plicatilis (4×104~10×104cells/cm3) and M. mongolica (10×104cells/cm3). When the two algae were mixed according to bloom densities, P. donghaiense at suitable densities to some extent could decrease the toxicity of A. catenella to B. plicatilis and M. mongolica. The results indicated that the large-scale HAB in the East China Sea could have adverse effect on zooplankton, and might further influence the marine ecosystem, especially when there was also Alexandrium bloom. 相似文献
5.
分别以高氮(摩尔C/N=8.5)、低氮(C/N=12.7)和氮添加(C/N=9.6)亚心形四爿藻(Tetraselmis subcordiformis)喂食安氏伪镖水蚤(Pseudodiaptomus annandalei)的幼体和成体,研究了此水蚤在不同氮条件下的生长、发育和摄食。随着藻细胞C/N比值的升高,安氏伪镖水蚤的生长速率从(0.067±0.001)/d减缓到(0.056±0.001)/d,同时,高氮条件下,幼体分别发育5d和18d后进入桡足幼体期和成体期,氮添加实验组与之相仿,低氮条件下则推迟到第8天进入桡足幼体期。随着藻细胞C/N比值的升高,安氏伪镖水蚤各个时期个体的氮含量显著降低,存活率也随之降低。处于高氮或氮添加条件下的无节幼体、桡足幼体和成体的氮摄食率[(0.53-0.95)×10?4mgN/(ind·h)]均比低氮条件[(0.32-0.6)×10?4mgN/(ind·h)]要高,但仅成体的碳摄食率在高氮条件下达(8.11±1.21)×10?4mgC/(ind·h),明显高于低碳条件下的(7.54±0.35)mgC/(ind·h)。结果表明:氮缺乏对安氏伪镖水蚤的生长发育和摄食等均有明显的抑制作用。氮添加条件下的饵料仅部分逆转这种抑制作用,暗示安氏伪镖水蚤的生长和摄食除受氮元素的直接限制外,还可能由于饵料在低氮时缺乏某些化合物而受限。 相似文献
6.
胶州湾及周边海域大气和海水中N_2O和CH_4的分布及海气交换通量 总被引：3，自引：0，他引：3
分别于2006年8月,12月和2007年4月,10月采集胶州湾及周边海域大气和海水样品,对氧化亚氮(N2O)和甲烷(CH4)浓度进行了测定,并设置1个连续站进行24 h连续观测.结果表明:大气中N2O春、夏、秋、冬的平均浓度(体积分数)分别为(3.17±0.03)×10-7,(3.24±0.15)×10-7,(3.19±0.02)×10-7和(3.08±0.25)×10-7;大气中CH4春、夏、秋、冬的平均浓度(体积分数)分别为(1.89±0.04)×10-6,(1.79±0.04)×10-6,(2.09±0.21)×10-6和(2.01±0.09)×10-6.胶州湾表、底层海水中N2O和CH4的浓度和饱和度表现出明显的季节变化,其中N2O浓度和饱和度冬季最高,春、秋季次之,夏季最低;CH4浓度和饱和度夏季最高,冬季最低.利用Liss and Merlivat(1986)公式和Wanninkhof(1992)公式估算出胶州湾海域N2O的年平均海-气交换通量分别为(11.16±14.15)和(22.42±27.56)μmol m-2·d-1;CH4分别为(7.75±6.19)和(17.76±14.84)μmol m-2·d-1.胶州湾大部分海域表层海水中N2O和CH4呈过饱和状态,是大气中N2O和CH4的净源. 相似文献
7.
以平板计数法,研究了不同浓度枯草芽孢杆菌(Bacillus subtilis)对泥蚶(Tegillarca granosa)及养殖底泥中细菌总数和弧菌总数的影响.试验分为1×10~6,5×10~6和10×10~6CFU/L 3个浓度试验组和对照组,试验共进行28 d,在第0、7、14、21和28天时采底泥和泥蚶,采用平板计数法检测细菌总数和弧菌总数.结果显示,在投施枯草芽孢杆菌后7 d内,养殖底泥和泥蚶体内细菌总数均呈明显上升趋势(P<0.05),7～28 d内缓慢下降,但差异不显著(P<0.05);投施枯草芽孢杆菌后,各试验组底泥和泥蚶体内弧菌总数显著低于对照组(P<0.05),5×10~6CFU/L和10×10~6 CFU/L试验组弧菌总数显著低于1×10~6CFU/L试验组(P<0.05).结果表明枯草芽孢杆菌具有抑制弧菌增殖的作用,枯草芽孢杆菌可应用于泥蚶池塘养殖. 相似文献
8.
9.
采用生物急性和慢性毒性实验的方法,研究了赤潮异弯藻对蒙古裸腹溞和日本新糠虾的毒性影响,并初步探讨了赤潮异弯藻导致二者较快死亡的机制。结果发现,赤潮异弯藻不仅对蒙古裸腹溞和日本新糠虾的存活有显著影响,而且使其个体变小、产幼前发育时间延长、总生殖量降低、平均存活时间缩短,种群数量增长受抑制。显微观察发现,蒙古裸腹溞能摄食赤潮异弯藻,但摄食后,其粪便紧紧地粘在蒙古裸腹溞的肠道末端;日本新糠虾不摄食赤潮异弯藻,但该藻粘附在其触须、附肢以及腹部、尾部的刚毛上,以及作为食物的卤虫幼体也被大量粘附在一起,聚集成团,或通过赤潮异弯藻粘附在日本新糠虾的附肢上。因此赤潮异弯藻很可能通过干扰蒙古裸腹溞和日本新糠虾正常的生理活动,而导致其快速死亡。 相似文献
10.
In order to provide pertinent evidence of ion channel with immune response in the fish,whole cell patch-clamp technique was employed for potassium ion channel study in turbot(Scophthalmus maximus) . Lymphocytes were isolated by Percoll density gradient centrifugation from peripheral blood samples,and electrophysiological characters of the channel were analyzed. In the recorded cells,activated voltage of the channels was-42.5 ± 3.7 mV and the average peak current was 313.12 ± 28.2 pA. The channel was identified as voltage dependent,the current was outward and it could be inhibited by 10 mmol/dm 3 TEA or 5 mmol/dm 3 4-AP,a specific potassium channel inhibitor,identifying the existence of potassium channel in peripheral lymphocytes of the turbot. 相似文献
11.
12.
The main objective of this study was to investigate toxic effects of the dinoflagellate Alexandrium species,on cladocera Moina mongolica in the laboratory.Ten strains of Alexandrium species,including Alexandrium tamarense(AT-6,ATHK,ATCI02,ATCI03 and AT5-1),A.catenella(ACDH),A.affine(AC-1 and AS-1),A.lusitanicum and A.minutum were tested.The results showed that A.tamarense(ATHK,ATCI02 and AT5-1) and A.affine(AC-1 and AS-1),but not A.tamarense(AT-6 and ATCI02),A.catenella(ACDH),A.lusitanicum and A.minutum had significantly negative effects on the survival of M.mongolica;when exposed to these ten strains of Alexandrium species in densities of 3 000 cells/cm 3 for 7 d,respecyively.M.mongolica could feed on A.tamarense(AT-6,ATHK,ATCI02,ATCI03 and AT5-1),A.catenella,A.lusitanicum and A.minutum,but exhibited little or no grazing on A.affine(AC-1 and AS-1),based on the changes in gut pigment after exposure to alga for 1 and 12 h.A.affine AC-1,which had the strongest toxicity on the survival of M.mongolica,was chosen to further study the negative effects on M.mongolica.The results showed that the effect of A.affine AC-1 on the survival of M.mongolica was density-dependent,and its lethal effects on one-day,two-day and three-day old M.mongolica were exacerbated with increasing age;The whole algal culture,re-suspended algal cells,cell fragments and cell contents all had adverse impacts on the survival of M.mongolica.Moreover,both juvenile numbers and life-span time of M.mongolica were decreased significantly when they were cultured in A.affine AC-1 of 10 and 50 cells/cm 3 ,combined with 3 × 10 6 cells/cm 3 of Chlorella spp.,respectively.As a non-PSP producer,A.affine may produce other toxins,responsible for the strong negative effects on M.mongolica. 相似文献
13.
14.
黑鱾血液的生理生化指标研究 总被引：2，自引：0，他引：2
本文采用F-820半自动血细胞分析仪和全自动生化分析仪，对黑纪的血液常规指标及血清中的17项生化指标进行了分析测定，并用Wright’s染色法制作血涂片对白细胞进行分类计数．结果表明：（1）黑纪的血红细胞数量为（2．49±0．47）×10^12个／dm^3；白细胞数量为（1．08±0．21）×10^11个／dm^3；在白细胞中以嗜中性粒细胞数量最多，占52．42％±4．67％，其次为淋巴细胞，占25．72％±2．88％；单核细胞体积最大，占总数的3．27％±0．62％．（2）黑纪红细胞脆性大，抗性差，在0．65％～0．70％的NaCl溶液中开始溶血，在0．50％～0．55％的NaCl溶液中完全溶血．（3）黑纪的血红蛋白（HGB）为109．11±15．72g／dm^3，高于一般鱼类，与其较强的耐低氧生理能力相适应．（4）血清中血糖浓度为4．72±1．35mmol／dm^3，明显低于凶猛肉食性鱼类，与其岛礁性生态习性和杂食性相吻合．（5）雌雄鱼的乳酸脱氢酶分别为332．67±188．48U／dm^3和905．66±257．85U／dm^3，雌鱼显著高于雄鱼，可能与繁殖活动相关． 相似文献
15.
钝顶螺旋藻部分原生质体及单细胞的制备与培养 总被引：21，自引：0，他引：21
于1992年1月-1994年4月，进行超声波处理方法制备钝顶螺旋藻部分原生质体以作为基因工程受体，以及制备单细胞用于固体平板克隆化培养的研究。研究结果表明：超声波以20kHz频率、15W功率作用30s，可使藻丝体断裂成15．0±1．6个细胞长度；延长作用时间，至2－6个细胞长度时，细胞壁结构遭到破坏，形成部分原生质体；继续作用，可形成少量原生质体和大量单细胞。断裂藻丝体、部分原生质体、单细胞以及原生质体均可涂布于固体培养基上再生或生长。以一定密度涂布单细胞与原生质体，能够形成彼此分开的单个克隆，可用于筛选及遗传分析。本文提供了一种节省溶菌酶的制备螺旋藻透性体的方法，超声波作用利于外源基因的导入，而涂布培养利于进一步的筛选和形成克隆。 相似文献
16.
Rapid amplification of cDNA ends(RACE) and real-time polymerase chain reaction(RT-PCR) were carried out to analyze the CYP4 gene expression in polychaete Marphysa sanguinea exposed to benzo[a]pyrene(BaP) in this study. The full length of MsCYP4 cDNA was 2 470 bp, and it encoded 512 amino acids. The deduced amino acid sequence showed 47% identity with CYP4 F from frog Xenopus tropicalis and shared high homology with other known CYP4 sequences. To analyse the role of CYP4 in protecting M. sanguinea from BaP exposure, three BaP groups were established: 0.5, 5 and 50 μg/L. Polychaetes were sampled after 3, 7 and 12 d. At 0.5 μg/L, the effect of BaP on MsCYP4 gene expression increased with time prolonged. MsCYP4 gene expression curve showed Ushaped trend with time in 5 and 50 μg/L BaP groups. Therefore, MsCYP4 gene may play an important role in maintaining the balance of cellular metabolism and protecting M. sanguinea from BaP toxicity. 相似文献
17.
2017年2月~2019年9月在灌河下游采集水样,分析了其中各种形态营养盐的浓度以及月动态变化情况,估算了灌河的营养盐入海通量。结果表明,NO3-和NH4+是溶解无机氮(DIN)的主要存在形式,其平均值分别为(74.66±45.06)、(83.67±87.22)μmol/L。NO3-浓度与欧洲以及国内一些河流相当,NH4+浓度显著高于世界上其它河流。PO43-的平均浓度为(3.38±2.14)μmol/L,显著高于世界河流的平均水平(0.32μmol/L),与欧洲和北美地区富营养化严重的河流相当。SiO32-的平均浓度为(80.27±27.65)μmol/L,同国内及世界上其它河流相比,该含量处于较低水平。不同形态氮、磷浓度存在显著的季节变化,从2017—2019年它们的浓度显著降低,这主要是由于环保督察后大量畜禽养殖场的关闭或迁移使得排放入河的各形态氮、磷大量减少所致;硅浓度的年际变化不大。灌河每年约有0.61×104 t的DIN和0.28×103 t的PO33-进入南黄海,SiO32-的年输送通量约为0.60×104t。 相似文献
18.
19.
利用静水密闭式呼吸仪,测定了不同温度（10、12、……、30℃）条件下褐菖鼬（Sebastiscus marmoratus）幼鱼耗氧率和排氨率变化．结果表明,温度对幼鱼耗氧率和排氨率均有显著影响（P〈0．05）．温度10～30℃,幼鱼耗氧率、排氨率变化范围分别为0．02～0．30mg／（g·h）和2．64～10．01ug／（g·h）,温度26、16℃时耗氧率和排氨率分别上升至峰值,分别为最小值10℃组的15．00、3．79倍;温度（F）对幼鱼耗氧率R0[mg／（g·h）]和排氨率RN[ug／（g·h）]的影响可分别用多项式表示：R0=-2．00×10^-5 T4＋1．50×10^-3 T3-3．69×10^-2 T2＋0．3978T-1．5376,R2=0．988和RN=3．00×10^-5 T6 -4．00×10^-3 T5＋0．1996 T4-5．1111T3＋70．817T2-501．10T＋1415．80,R2=0．964;幼鱼的氨熵变化范围为0．02～0．19,其蛋白质供能比变化范围为5．64％～56．65％,平均蛋白质供能比为22．56％;各温度跨度代谢率Q10值均值为4．02,18～28℃代谢率Q10值为2．81±0．09与鱼类平均Q10值较接近;各温度跨度组排泄率Q10均值为0．93,对比同一温度跨度组代谢率和排泄率Q10值,代谢率Q10值均大于排泄率Q10值两倍以上,最大组间相差达7倍．因此,幼鱼能量消耗的供能物质以脂肪和碳水化合物为主,蛋白质为辅．此外,温度变化对幼鱼代谢的影响程度明显大于对排泄的影响,且其适宜生长温度为18～28℃． 相似文献
20.
Vertical profiles for the uranium-series radioisotopes 210Pb and 210Po were obtained at thetwo hydrothermal vent sites, the Iheya Ridge and the Minami-Ensei Knoll, in the Mid-Okinawa Trough in 1993 and 1994, respectively. In 1995, both radioisotopes were measured at the Minami-Ensei Knoll a-gain. At the Iheya Ridge, where the hydrothermal activity is not active as reflected by the CH_4, and 222Rn data, both the total 210Pb and 210Po activities show deficiency relative to their parents, and the mean residence time of 210Pb and 210Po is approximately equal to 20 and 2-5 a, respectively. At the Minami-Ensei Knoll, which is characterized by black smokers, the total 210Pb(0.167 × 10~(-3)-2.5 × 10~(-3)_ Bq/kg) around the plumes is deficient relative to 226Ra but the total 210Po activities (1.83 × 10 ~(-3) - 2.83 × 10~(-3) Bq/kg) are in excess relative to 210Pb. The 210Po activities are higher than those in the East China Sea and the Okinawa Trough and excess 210Po has been found. The 210Pb/226Ra and 210Po/ 相似文献