利用有益微生物改善养殖生态环境的研究

研究了噬菌蛭弧菌在实验室条件下对水产养殖中常见病菌的裂解能力及噬蛭弧菌的光合细菌对池塘生态环境的改善作用。结果表明，噬菌蛭菌对嗜水气单胞菌具有裂解作用，噬菌蛭弧菌和光合细菌结合使用对养殖环境具有明显的改善作用。25d实验组比对照组池塘中的细菌总数少2个数量级，70d后实验组比对照组池塘中的细菌总数少3个数量级，25d对照组COD为6．35mg/L，使用噬菌蛭 菌浓度为3，5，10mL/m^3及光合细菌皆为5mL/m^3实验组的COD分别为4．67，4．16，4．18mg/L；25d后对照组NH3－N为0．49mg/L，使用噬菌蛭弧菌浓度为3，5,10mL.m^3及光合细菌皆为5mL/m^3实验组的NH3－N分别为0．36，0．33，0．32mg/L，90d后对照组NH3－N为0．41mg/L，使用噬菌蛭弧菌浓度为3，5，10mL/m^3，及光合细菌皆为5mL/m^3实验组的NH3－N分别为0．27，0．22，0．21mg/L,55d后对照组硫化的为0．011mg/L，使用噬菌蛭弧菌浓度为3，5，10mL/m^3及光合细菌皆为5mL/m^3实验组的硫化物分别为0．010，0．008，0．008mg/L。     

噬菌弧菌N1对淡水和海水养殖水体细菌群落影响PCR-DGGE分析

【目的】研究噬菌弧菌Bacteriovorax sp. N1在一个投放周期内对淡水和海水养殖环境中细菌、弧菌总数及细菌群落结构的影响。【方法】自市售微生态制剂分离蛭弧菌N1并进行分子鉴定,测定其裂解效果,制备高浓度N1菌液分别投放至淡水红鲤鱼(red carp)和海水仿刺参(Apostichopus japonicus)养殖水体,采用细菌平板计数法及PCR-变性梯度凝胶电泳(PCR-DGGE)技术分析48 h内水体环境中细菌、弧菌总数及细菌群落结构变化。【结果】经鉴定蛭弧菌N1为噬菌弧菌,其对大肠杆菌(Escherichia coli)、溶藻弧菌(Vibrio alginolyticus)、黄海希瓦氏菌(Shewanella smarisflavi)、灿烂弧菌(Vibrio splendidus)、哈氏弧菌(Vibrio harveyi)和金黄色葡萄球菌(Staphylococcus aureus)均有裂解效果。将噬菌弧菌N1投放进淡水和海水养殖环境的12～24 h,其能显著降低两种环境中弧菌含量(P 0.05)。DGGE分析显示添加噬菌弧菌N1后淡水组优势菌群弧菌属(Vibrio,a1)和不可培养杆菌属(Uncultured bacterium, a5)在12 h以后含量有明显的减少,假单胞菌属(Pseudomonas, a3)和红杆菌科Shimia属(Shimia, a6)菌含量增加。海水组优势菌群不可培养杆菌属(c2)菌在12 h时变成非优势菌群,而白杆菌属(Albirhodobacter,c1)增加成为优势菌群。噬菌弧菌N1在水中含量在24 h时降至最低。【结论】噬菌弧菌N1对海水和淡水环境中的弧菌属和不可培养杆菌属菌群有明显的裂解作用导致其含量下降,但也使假单胞菌属(Pseudomonas),红杆菌科Shimia属和白杆菌属(Albirhodobacter)菌群含量增加,但生物效应不明。为维持噬菌弧菌N1对弧菌的控制,需要24 h左右重新补充投放。     

水体中NH3-N对建鲤非特异性免疫功能的影响

用 0 .1、0 .5、1.0、2 .0和 5.0 mg/ L NH3- N分别刺激建鲤 10 d和 2 0 d后 ,测定了建鲤非特异性免疫指标 ,估测不同浓度的 NH3- N对建鲤非特异性免疫指标的影响。 0 .1、0 .5mg/ L的 NH3- N对建鲤NBT阳性细胞、溶菌酶活性无影响 ,1.0 mg/ L的 NH3- N可使 NBT阳性细胞数和溶菌酶活性降低 ,而2 .0和 5.0 mg/ L则使 NBT阳性细胞数和溶菌酶活性显著下降 ( P<0 .0 5)。这些结果表明水体中 0 .1、0 .5mg/ L的 NH3- N对建鲤非特异性免疫功能无影响 ,1.0 mg/ L的 NH3- N略有影响 ,而 2 .0和 5.0mg/ L的 NH3- N则明显降低了建鲤的非特异性免疫功能     

不同感染复数下海洋蛭弧菌DA5对溶藻弧菌的控制效率

【目的】研究宿主菌密度和感染复数对海洋蛭弧菌捕食弧菌效率的影响。【方法】以溶藻弧菌(Vibrio alginolyticus)zouA(下称"zouA")为宿主,通过海水共培养实验研究海洋蛭弧菌菌株DA5(下称"DA5")在初始宿主密度10~3~10~8 cfu/mL下24 h的生长,评估低感染复数和高感染复数下DA5对zouA 10 d的生物控制效果。【结果】DA5捕食所需最低zouA密度约为5×10~5 cfu/mL;在zouA密度≥10~6 cfu/mL时,DA5方对其发挥控制效应,且感染复数越高捕食效率越高,即使感染复数低至0.001,一定时间后DA5亦可有效控制zouA数量。而当初始zouA密度低至10~4 cfu/mL时,DA5需在感染复数≥100条件下方可显著控制zouA。【结论】宿主密度与感染复数均影响海洋蛭弧菌DA5对溶藻弧菌的控制效果。     

有效微生物菌群对养虾水体细菌生态和水质的影响

研究有效微生物菌群(EM)对养虾水体中异养细菌、弧菌、光合细菌、放线菌的数量以及水体水质的影响。结果表明,在养殖池中添加EM,对水体中的异养细菌、弧菌、光合细菌及放线菌的数量均有显著影响:实验组异养细菌数量比传统对照池减少40.0%,弧菌数量减少7.8%,光合细菌数量增加98.2%,放线菌数量增加99.2%。EM能改良水质条件,与对照组相比,实验组溶解氧提高11.0%,COD降低8.0%,氨氮含量降低20.7%,亚硝酸氮含量降低10.0%。另外,实验组对虾成活率比对照组提高23.08%,饵料系数下降9.4%,利润提高了16.11%。     

49味中药及其复方与抗生素对溶藻弧菌的体外抑菌作用

【目的】筛选对溶藻弧菌(Vibrio alginolyticus)有抑菌作用的中草药及其复方以及抗生素。【方法】采用改良的牛津杯法对诃子、白芍、甘草等49种单味中药进行溶藻弧菌体外抑菌试验,以体外抗菌活性较好的22种药物,按中药配伍规则组成二联、三联复方,采用生药质量浓度分别为60、240 mg/mL的中药进行中药复方体外抑菌试验。用抗生素对溶藻弧菌进行药敏试验。【结果】当单种中药体外抑菌药物质量浓度为240 mg/mL时,诃子、乌梅、醋五味子等对溶藻弧菌抑菌作用明显,为极敏感。在二联中药体外抑菌试验中,当中药质量浓度为60mg/m L时,诃子、乌梅组成复方中药等8种复方对溶藻弧菌协同抑菌作用明显,为极敏感,药物质量浓度在240mg/m L时,诃子与白芍等14种双联中药的协同抑菌作用明显,为极敏感。在三联中药体外抑菌试验中,在药物质量浓度60 mg/mL时,诃子、乌梅、蒲公英等组成24种复方中药按质量比1∶1∶1的抑菌效果极为敏感,药物质量浓度在240mg/m L时,黄芩、诃子、黄芪等22复方中药按质量比1∶1∶1对的抑菌作用明显,为极敏感。溶藻弧菌对恩诺沙星、盐酸多西环素、土霉素及甲氧苄啶/磺胺甲噁唑4种药物高度敏感。【结论】18种单味中药对溶藻弧菌有抑制作用,黄芩、诃子、黄芪等24个三联复方中药药效较强,多个抑菌作用效果良好的三联复方中药可用于鱼病防治研究。     

红海湾养殖区底质水中氮、磷的分布特征

着重研究了红海湾养殖区底质水中 NO-3 -N、NO-2 -N、NH 4-N、PO3 -4 -P、有机质及 c( NO-3 -N) /c P 和 ∑c N/c P( ∑c N=c( NO-2 ) c( NO-3 ) c( NH 4) )比值的分布特征 ,并对该湾低质水中氮、磷及有机质的季节变化及其它们之间的相互关系作了讨论 ,结果表明 :在春、夏、冬三个季节中 ,NH 4-N的浓度比NO-2 -N及 NO-3 -N高 ,春季 NH 4-N的平均浓度为 92 .60 μm ol/L,占总无机氮 80 .57% ;夏季浓度为4 7.0 4μmol/L ,占总无机氮 61 .64 % ;冬季 NH 4-N的浓度最低 ,为 9.60μmol/L ,占总无机氮 4 5.76% ;而夏季 PO3 -4 -P浓度及有机质的含量比春、冬季高 ,分别为 53 .68μm ol/L和 1 .3 62 %。分析指出该湾底质水中无机氮是以 NH 4-N为主要存在形态。     

光合细菌对养殖水质及凡纳滨对虾抗病力的影响

在凡纳滨对虾养殖环境中人工引入不同浓度的光合细菌,监测氨氮、亚硝酸氮、化学需氧量的变化,15d后测定凡纳滨对虾的AKP、POD、PO、SOD、抗菌、溶菌活力,以及不同光合细菌浓度下凡纳滨对虾的成活率与体重增长率,研究光合细菌对水质和凡纳滨对虾抗病力的影响。结果表明,引入光合细菌可显著降低水体化学需氧量、氨氮含量,并抑制亚硝酸盐氮的产生,提高凡纳滨对虾的抗病力。当光合细菌投放浓度为3×103/mL时,水体中化学需氧量、氨态氮、亚硝酸盐氮含量的均值分别比对照组降低31.59%、43.42%、52.20%,差异显著(P<0.05);对虾的AKP、POD、PO、SOD、抗菌、溶菌活力分别比照组提高31.92%、72.29%、55.56%、31.61%、39.07%、69.51%,差异显著(P<0.05);成活率,体重增长率分别比对照组提高18.67%、34.03%,差异显著(P<0.05)。     

溶藻弧菌疫苗对凡纳滨对虾免疫功能的影响

应用溶藻弧菌疫苗饲喂凡纳滨对虾,测定了弧菌疫苗对凡纳滨对虾免疫指标的影响以及 疫苗的免疫保护作用。结果发现,投喂弧菌疫苗后,溶菌活力在12～20d内迅速增强,在20d时 活力达到最高,VF1组高于VF2和VF3组,但VF2和VF3之间差异不显著;凝集效价在投喂后的 第8天开始升高,在14d时达到最高,实验组的凝集活力均高于对照组,但实验组之间无明显的差 异;而超氧化物歧化酶(SOD)活力和溶血活力变化不明显。以每克饲料含疫苗细胞1.0×109、 1.0×108和1.0×107个的浓度投喂,对凡纳滨对虾的免疫保护率分别为66.7%、46.7%和13.3%。 可见弧菌疫苗对凡纳滨对虾的免疫保护率随疫苗浓度的增大而升高。     

氨氮胁迫对马氏珠母贝免疫活性的影响

在实验室条件下探讨氨氮胁迫对马氏珠母贝(Pinctada martensii)血细胞密度、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、溶菌酶(LSZ)、酸性磷酸酶(ACP)活性的影响。结果表明:1)不同浓度氨氮(1.25~40 mg/L)胁迫3 d后,马氏珠母贝血细胞密度随氨氮浓度的增加呈下降趋势,当氨氮浓度超过5 mg/L时血细胞密度较对照组明显下降,差异极显著(P<0.01);2)血清SOD活性随实验氨氮浓度(1.25~40 mg/L)的增加而明显下降,在较低氨氮浓度(1.25~5 mg/L)时,SOD活性高于对照组,氨氮浓度超过10 mg/L时,SOD活性低于对照组,各实验组SOD活性与对照组均存在极显著差异(P<0.01);3)当氨氮浓度为1.25~20 mg/L时,马氏珠母贝血清CAT活性随氨氮浓度的增加而升高,除氨氮1.25 mg/L组外,其余各实验组血清CAT活性较对照组极显著升高(P<0.01),当氨氮浓度为30~40 mg/L时,血清CAT活性呈急剧下降趋势,且低于对照组(P<0.01);4)马氏珠母贝血清LSZ活性随实验氨氮浓度的增加而降低,当氨氮浓度为10 mg/L以下时,血清LSZ活性高于对照组,当氨氮浓度为20 mg/L以上时,血清LSZ活性较对照组极显著降低(P<0.01);5)氨氮浓度为1.25~10 mg/L时,马氏珠母贝血清ACP活性随氨氮浓度的增加而升高,且高于对照组(P<0.01),当氨氮浓度超高20 mg/L时,马氏珠母贝血清ACP活性随氨氮浓度的增加急剧降低,且低于对照组(P<0.01)。     

黄土高原沟壑区原状土壤氮素迁移

以中国生态系统研究网络CERN长武王东沟实验站的坡耕地和塬耕地为供试土壤,研究了黄土高原沟壑塬区旱耕地原状土壤氮素迁移和时空变异。结果表明:耕作土壤NO3--N为23.1~33.8 mg/kg,NH4+-N为0.23~0.50mg/kg,DOC为9.17~13.38 mg/kg,P为0.18~0.23 mg/kg;坡耕地和塬耕地的NO3--N和NH4+-N主要集中在0~20 cm的上层土壤,中下层土壤NO3--N和NH4+-N起源于上层淋溶迁移和累积;高含量时养分淋溶溶出呈指数衰减型;NO3--N、NH4+-N、DOC向下层的迁移塬耕地慢于坡耕地。     

Regulation of water quality and growth characteristics of indoor raceway culture of <Emphasis Type="Italic">Litopenaeus vannamei</Emphasis>

Two modes of regulating the water quality of experimental ponds in indoor raceway culture of Litopenaeus vannamei were evaluated using simple water treatment facilities. A self-made water purifying net, aeration stone, composite microbe preparation, and Ceratophyllum demersum were placed in the experimental ponds and the culture water was circulated along the raceway inside the pond using a paddle wheel aerator. In addition, the water quality in the experimental pond was improved by draining effluent from the pipeline at the bottom of ponds 7 and 8 (mode I) and exchanging the circulating water in pond 10 (mode II) with the reservoir water in pond 9 using a pump and pipeline. The water quality in the experimental ponds was similar in response to regulation using mode I or mode II. Water quality parameters in the experimental ponds were controlled within a suitable range by simple facilities during culture period without using any chemical treatments. The rich content of dissolved oxygen was maintained by the circular flow and continuous aeration of the pond water. The respective average values of the main water parameters in experimental ponds 7 and 10 in response to regulation of the water quality using modes I and II were as follows: pH 8.17 and 7.99; DO 5.16 mg/L and 5.97 mg/L; COD_Mn 18.45 and 12.61 mg/L; TAN (NH₃-N) 0.854 mg/L (0.087 mg/L) and 0.427 mg/L (0.012 mg/L); NO₂-N 0.489 mg/L and 0.337 mg/L. Moreover, the average body length and body weight of harvested shrimp of pond 7 and pond 10 were 7.56 cm and 8.99 cm, 5.10 g and 8.33 g, respectively. Furthermore, the survival rate, average biomass yield and average condition factor of the shrimp harvested were 70% and 60%, 2.54 kg/m² and 2.14 kg/m², and 0.675 g/cm and 0.927 g/cm, respectively. Linear equations describing the relationship between body length and culture time and cubic or power functions describing the relationship between body weight and body length were obtained based on evaluation of the growth data of shrimps throughout the culture period.     

Abundance and spatial dynamics of bacterioplankton in the Seven Rila Lakes, Bulgaria

In the high mountain oligotrophic Seven Rila Lakes (2 095–2 535 m a.s.l.) bacterial abundance was recorded in July and September 2006. In July, bacterial abundance (average (3.32±2.5)×10⁵ cell/ml) in the lakes correlated negatively with elevation, while in September (average (26.39±7.1)×10⁵ cell/ml) this pattern was altered and the greatest abundance of bacteria occurred at the highest ((39.05±1.5)×10⁵ cell/ml) and the lowest ((30.63±6.0)×10⁵ cell/ml) elevated lakes. Regression analyses suggested that the principal factor controlling bacterial abundance, in both July and September, was inorganic nitrogen (NO₃-N and NH₄-N; R ²=0.70, P<0.05). Other major regulating factors were temperature (R ²=0.66, P<0.03) in July and filter-feeding zooplankton (R ²=0.95, P<0.01) in September. All factors, except NO₃-N, had a positive effect on bacterial abundance.     

Effects of salinity and nutrients on the growth and chlorophyll fluorescence of Caulerpa lentillifera

Caulerpa lentillifera is a green algae that distributes worldwide and is cultivated for food. We assessed vegetative propagation of C. lentillifera by measuring the specific growth rate(SGR) and chlorophyll fluorescence of the green algae cultured at different salinities and nutrient levels. The results indicated that C. lentillifera can survive in salinities ranging from 20 to 50,and can develop at salinities of 30 to 40. The maximum SGR for C. lentillifera occurred at a salinity of 35. Both chlorophyll content and the ratio of variable to maximum fluorescence( Fv / Fm) were also at a maximum at a salinity of 35. Photosynthesis was inhibited in salinities greater than 45 and less than 25. Both the maximum SGR and maximum chlorophyll content were found in algae treated with a concentration of 0.5 mmol/L of NO3-N and 0.1 mmol/L of PO 4-P. The photosynthetic capacity of photosystem II(PSII) was inhibited in cultures of C. lentillifera at high nutrient levels. This occurred when NO3-N concentrations were greater than 1.0 mmol/L and when PO4- P concentrations were at 0.4 mmol/L. As there is strong need for large-scale cultivation of C. lentillifera,these data contribute important information to ensure optimal results.     

Heterotrophic bacterial floras in industrial area and unpolluted marine environments around Qingdao

From Oct. 1999 to Oct. 2000, the heterotrophic bacterial floras in the industrial marine environment around the Qingdao Power Plant (QPP) and in the unpolluted marine environments were investigated. The results showed that the numbers of the heterotrophic bacteria around QPP were much higher than those in unpolluted environments, and the average numbers in QPP Seawater, QPP Sediment, Unpolluted Seawater and Unpolluted Sediment were 5.4×10⁴cfu(mL)⁻¹, 5.0×10⁵cfug⁻¹, 3.0×10²cfu(mL)⁻¹ and 1.3×10⁵cfug⁻¹ respectively. Totally, 118 strains were isolated from QPP and 99 of them were Gram-negative. One hundred and twenty one strains were isolated from the unpolluted environments and 104 of them were Gram-negative. All the Gram-negative bacteria belonged to 13 genera. The distribution of the bacteria was varied in different marine environments. The results showed that the unpolluted marine environments contained much more Vibrio than seawater and sediment around QPP.     

The release behavior of inorganic nitrogen and phosphorus in sediment during disturbance

Sediments and surface water were sampled in a tide flat in the Huiquan Bay, Qingdao, China in January 2004 to simulate the exchange of NH4-N/NO3-N/ PO 43- between sediments and surface water. A working system was designed with which samples were shaken at 60, 120 and 150 revolutions per minute (r/min). Experiment results show that NH4-N concentration in water at shaking rate of 60r/min decreased gradually, while at 120r/min increased gradually. In resuspension, fine-grained sediments contributed most NH4-N to the seawater, followed by medium-grained and coarse-grained sediments. The NO3-N concentration in water had a negative relation with the shaking rate; the medium-grained sediments contributed more NO3-N to seawater than the coarse-and fine-grained sediments. The PO 43- concentration is positively related with the shaking rate, the fine-grained sediments were the main N and P contributor to the seawater, followed by medium-and coarse-grained sediments.     

The release behavior of inorganic nitrogen and phosphorus in sediment during disturbance

Sediments and surface water were sampled in a tide flat in the Huiquan Bay, Qingdao, China in January 2004 to simulate the exchange of NH4-N/NO3-N/PO4^3- between sediments and surface water. A working system was designed with which samples were shaken at 60, 120 and 150 revolutions per minute （r/min）. Experiment results show that NH4-N concentration in water at shaking rate of 60 r/min decreased gradually, while at 120 r/min increased gradually. In resuspension, fine-grained sediments contributed most NH4-N to the seawater, followed by medium-grained and coarse-grained sediments. The NO3-N concentration in water had a negative relation with the shaking rate; the medium-grained sediments contributed more NO3-N to seawater than the coarse- and fine-grained sediments. The PO4^3- concentration is positively related with the shaking rate, the fine-grained sediments were the main N and P contributor to the seawater, followed by medium- and coarse-grained sediments.