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1.
为探究光合细菌与芽孢杆菌复合微生物制剂的净水能力,以实验室分离保存的1株光合细菌PSB1和1株芽孢杆菌BS1为研究对象,通过测量人工污水中氨氮质量浓度、硫化物质量浓度、化学需氧量的变化确定2株菌混合的最优密度配比为2∶1。在该混合配比下,污水中氨氮的质量浓度由4.68 mg/L降至0.39 mg/L,硫化物质量浓度由0.62 mg/L降至0.26 mg/L,化学需氧量由4.02 mg/L降至2.35 mg/L。安全性试验表明,复合微生物净水剂砷含量为0.017 mg/kg,镉含量为1.634×10~(-4) mg/kg,均低于国家标准中规定的含量,且未检测出黄曲霉素B_1、志贺氏菌等成分,符合安全标准。为进一步探究复合微生物净水剂对养殖污水水质的影响,研究在仿刺参养殖试验过程中投放该复合微生物净水剂,测量养殖污水中化学需氧量及氨氮、硫化物质量浓度变化。结果表明,在水体pH 7.0~8.5、盐度25~35时,复合微生物净水剂对氨氮、硫化物和化学需氧量均有很好的降解作用。  相似文献   

2.
采用移动床生物膜反应器(MBBR)处理低浓度氨氮养殖废水,在不同水力停留时间(HRT)和不同曝气条件下,分析MBBR处理人工模拟的低浓度氨氮(2 mg/L左右)养殖废水的进出水氨氮、亚硝酸盐氮和硝酸盐氮的浓度变化,探讨HRT和曝气量对MBBR处理低浓度氨氮养殖废水的影响,并以实际鲟鱼养殖废水(氨氮浓度0.5~1.5 mg/L)和其他研究成果进行验证和比较.结果显示:MBBR的最优HRT为6~8 min,最优曝气量为180 L/h,相应的氨氮去除率为70% ~ 75%,氨氮去除负荷为560~700 g/(m3.d),填料生物膜厚度为26~38 μm;膜表层结构多样,物种丰富,膜生长良好.该反应器对处理低浓度氨氮养殖废水具有的高效能力.  相似文献   

3.
为了建立优化的循环海水养殖系统,采用水质国标检测方法分析了珊瑚石生物滤池在不同氨氮和溶解氧(DO)负荷实验条件下对养殖废水中氨氮、化学耗氧量(COD)及颗粒悬浮物(SS)的处理效果。结果显示,进水氨氮浓度对出水氨氮(正相关)、COD(正相关)均有极显著的影响(P0.01),对SS处理效果影响不显著。当进水氨氮浓度为0.45~0.65 mg/L时,滤池对水体处理效果最优(氨氮平均清除率为82.1%±3.3%;COD平均清除率为7.1%±1.5%;SS平均清除率为5.8%±1.6%)。DO浓度对水体氨氮(负相关)和COD(负相关)处理效果的影响显著(P0.05),对SS处理效果影响不显著。DO浓度为5.0~7.0 mg/L时,水体处理效果最优(氨氮平均清除率为78.7%±3.5%;COD平均清除率为23.0%±5.3%;SS平均清除率为7.1%±2.0%)。因此,本实验环境下的循环海水养殖系统珊瑚石生物滤池在氨氮浓度为0.45~0.65 mg/L,DO浓度为5.0~7.0 mg/L时,对水体中的氨氮、COD、SS的综合处理效果最优。  相似文献   

4.
为研究芽孢杆菌和光合细菌协同作用对刺参养殖水质及其生长、消化和免疫的影响,测定了水体化学需氧量(COD)、氨氮(NH4+-N)和亚硝酸盐氮(NO2--N)24 h的变化量、肠道蛋白酶和淀粉酶的活性以及体腔液超氧化物歧化酶(SOD)、碱性磷酸酶(AKP)和溶菌酶(LSZ)的活力。结果显示,混合菌投喂组优于单一菌投喂组。在芽孢杆菌和光合细菌投喂浓度以1.86×105和1.75×104CFU/mL搭配时,该实验组协同作用效果最优,水体COD、NH4+-N和NO2--N含量均显著低于对照组(P<0.05);刺参特定生长率最大(0.76%/d),较对照组提高56.8%,成活率亦最高(97.8%);蛋白酶和淀粉酶活性最高(96.72和98.72 U/mg prot),较对照组显著提高149%和44.82%;体腔液SOD活力最高(65.16 U/mL)。而两种菌对刺参AKP和LSZ活力的影响较小。研究表明,芽孢杆菌和光合细菌搭配合理效果更佳,能够有效改善养殖环境,提高刺参消化酶活性和免疫力,促进刺参生长。  相似文献   

5.
为减少高密度养殖下菲牛蛭(Hirudinaria manillensis)疾病发生和养殖废水排放,研究比较了3种商品化有益微生物制剂(硝化细菌T1、光合细菌T2和EM复合菌T3)对养殖水体的净化效果。结果表明,3种有益微生物制剂在15d内均能使养殖水体的pH稳定在6.8以上,溶氧量(DO)分别比对照组提高30.12%、26.95%和46.12%;化学耗氧量(COD)分别比对照组低1.02mg/L、1.13mg/L和1.53mg/L;3个处理组对氨氮(NH4+-N)的平均降解率分别为48.48%、45.23%和63.10%,亚硝态氮(NO2-N)平均值分别比对照组低0.16mg/L、0.19mg/L和0.27mg/L;菲牛蛭存活率均高达90%以上,明显高于对照组的53%。3种有益微生物制剂均有显著增加溶氧量、降低氨氮、亚硝态氮和化学耗氧量的效应,对菲牛蛭养殖水体均具有很好的净化作用,其中以EM复合菌效果最佳。  相似文献   

6.
竹子填料海水曝气生物滤器除氮性能   总被引:5,自引:0,他引:5       下载免费PDF全文
生物滤器是循环水养殖系统的关键水处理单元,主要用于去除水体中水溶性的氮化物.采用人工模拟海水养殖废水,在系统运行的水力停留时间HRT为1h,水温为18~25 ℃,气水比为3∶1,初始C/N=3∶1,pH为8.05~8.53条件下,对竹子填料浸没式生物滤器的挂膜过程和稳定运行阶段系统去除氨氮的运行特性,以及挂膜过程中的硝化细菌群落变化进行了实验研究.结果表明,在较低的NH+4-N浓度条件下,采用竹子填料的生物滤器有较快的挂膜速度,挂膜成功后滤料表面上生长的氨氧化细菌和亚硝酸氧化细菌的数量分别为4.5×105、1.5×105(光面)和1.1×106 CFU/ml(粗面).具有较高且稳定的氨氮去除效果,氨氮去除效率达到80%,出水浓度小于0.06 mg/L,满足海水循环养殖系统中的应用要求.  相似文献   

7.
本实验旨在筛选对米尔伊丽莎白菌(Elizabethkingia miricola)有抑制作用的拮抗菌,并对其生长特性及其去除氨氮和亚硝酸盐的作用进行分析。实验采用平板对峙法从“稻蛙”养殖稻田土壤中分离到1株对米尔伊丽莎白菌有较强抑制作用的菌株X2。采用形态学特征观察和16s rDNA测序对X2进行鉴定,随后对X2在不同pH、盐度、温度等条件下的生长曲线进行了测定,以评估其环境适应性,并将X2接种于氨氮和亚硝酸盐培养基中,测定去除率以评估其去除氨氮和亚硝酸盐的能力。结合形态学特征及菌株16s rDNA序列分析,X2鉴定为侧孢短芽孢杆菌(Brevibacillus laterosporus)。结果显示:X2在pH 5~9、盐度5‰~50‰、温度20~40℃之间均能生长,最适pH、盐度、温度分别为7、5‰和35℃。这表明X2对环境的适应性较强,具有较强的耐酸碱性、耐盐性,适温性广等特性。X2在去除氨氮、亚硝酸盐方面也表现出了很强的能力,在X2接种浓度为5.0×107 CFU/mL时氨氮的去除率最高,达到74.95%;接种浓度为5.0×105 CFU...  相似文献   

8.
通过监测池塘水体藻类群落组成、多项水质指标、底泥总有机碳(TOC)和底泥异养细菌数等指标值,研究了固定化微生物对凡纳滨对虾生产性养殖池塘水质调控和污染底泥的修复能力,微生物固定所用载体为改良沸石和生物活性炭(相应的固定化微生物分别记为ZE-M组和BE-M组)。试验结果显示,处理组(ZE-M组和BE-M组)池塘水体中藻类组成呈多元化,隐藻、蓝藻和绿藻数量比较接近,而对照组则是蓝藻占绝对优势。试验过程中,对照池的氨氮浓度和COD呈直线上升,而处理组氨氮浓度和COD的增长幅度缓慢,ZE-M、BC-M载体微生物的使用是产生差异的直接原因。对照组和处理组的其它水质指标变化规律及差异性不明显,可能是由于池塘水体由诸多不确定因素影响所致。固定化微生物对池塘底泥TOC含量和异养细菌数的影响显著(P<0.05),试验过程中,试验组和对照组池塘底泥TOC含量随着养殖时间均有增加的趋势,但对照组这一趋势更加明显;试验初期,各组表层底泥中的异养细菌数量在3.367×105~8.60×105CFU/g范围内,试验结束时增长到85×105~393.7×105CFU/g。处理组和对照组的异养细菌差异显著(P<0.05),其中ZE-M处理组...  相似文献   

9.
从对虾养殖池中分离到1株细菌(编号2013042402,简称菌株02),分别用16S rDNA序列比对法和细菌全细胞脂肪酸气相色谱法对该菌进行鉴定.结果显示,菌株02为芽孢杆菌(Bacillus sp.).为探讨该芽孢杆菌在生物絮团对虾养殖中的使用效果,实验分别设置加菌加糖组(菌株02的量为2.0× 104 CFU/ml,蔗糖量为饵料的70%)、加菌组、加糖组(生物絮团组)及空白对照组,研究了菌株02对养殖水质(温度、盐度、溶氧、pH、氨氮及亚硝酸氮)、对虾存活率及水体中主要菌群组成等指标的影响.结果显示,加菌加糖组能显著降低养殖水体中的氨氮和亚硝酸氮浓度,提高对虾存活率.生物絮团对虾养殖系统中添加菌株02,能够改善菌群结构,抑制弧菌生长.研究结果可为生物絮团对虾养殖中定向培养有益微生物提供技术支持.  相似文献   

10.
枯草芽孢杆菌的培养条件及对水质的净化作用   总被引:19,自引:3,他引:16  
研究了枯草芽孢杆菌(Bacillus subtilis Cohn,1872)(菌株编号:LB-B3)的培养条件及其在净化对虾养殖池水样方面的效果。实验分别设置了9个不同的pH值梯度(pH 2~10)和6个不同接种量梯度(0.3%、0.5%、1%、3%、5%和7%),以吸光值(OD)为生长指标,进行了枯草芽孢杆菌培养条件的优化实验;同时又设置了5个不同接种浓度(0 CFU/mL、5.2×104CFU/mL、1.04×105CFU/mL、1.56×105CFU/mL和2.08×105CFU/mL)接种待处理水样,测定了96 h内化学耗氧量、亚硝酸氮、氨态氮和溶氧等4个水质指标的变化情况。结果表明:pH=7.0、接种量为7.0%时,OD值最大;枯草芽孢杆菌能显著净化水质,但使用后会暂时性增加耗氧。  相似文献   

11.
12.
The environmental processes associated with variability in the catch rates of bigeye tuna in the Atlantic Ocean are largely unexplored. This study used generalized additive models (GAMs) fitted to Taiwanese longline fishery data from 1990 to 2009 and investigated the association between environmental variables and catch rates to identify the processes influencing bigeye tuna distribution in the Atlantic Ocean. The present findings reveal that the year (temporal factor), latitude and longitude (spatial factors), and major regular longline target species of albacore catches are significant for the standardization of bigeye tuna catch rates in the Atlantic Ocean. The standardized catch rates and distribution of bigeye tuna were found to be related to environmental and climatic variation. The model selection processes showed that the selected GAMs explained 70% of the cumulative deviance in the entire Atlantic Ocean. Regarding environmental factors, the depth of the 20 degree isotherm (D20) substantially contributed to the explained deviance; other important factors were sea surface temperature (SST) and sea surface height deviation (SSHD). The potential fishing grounds were observed with SSTs of 22–28°C, a D20 shallower than 150 m and negative SSHDs in the Atlantic Ocean. The higher predicted catch rates were increased in the positive northern tropical Atlantic and negative North Atlantic Oscillation events with a higher SST and shallow D20, suggesting that climatic oscillations affect the population abundance and distribution of bigeye tuna.  相似文献   

13.
Previously, we reported 10 PEGE types of 85 tilapia Streptococcus agalactiae(GBS), which shifted from Streptococcus iniae in China, by using PEGE method. Presently, larger and more representative tilapia GBS were isolated, for the ?rst time in China, to characterize their serotypes and genetic diversities more precisely than had done before. 168 GBS strains were distributed in ?ve provinces of China, in which Guangdong, Guangxi and Hainan were the major ones, holding36.9%(62/168), 37.5%(63/168) and 19.6%(33/168), respectively. Serotypes, Ia, Ib and III, were observed in these strains and the most predominant one was Ia(95.2%), which mainly distributed in Guangdong, Guangxi and Hainan. Ia initially occurred in 2009, it shoot up to 32.1% in 2010,but decreased to 16.1% in 2011 before went up to 45.2% in 2012. Ib sporadically occurred during2007–2011, III onlyoccurred in 2012. 14 different PFGE types, including 4 new types(N, O,P and Q), were observed, in which B, D, F and G were the predominant types, holding 83.9%(141/168) of the total GBS strains. Ia corresponded to 11 PFGE types(A–H, N–P), in which type D predominated(51%). Ib represented 3 genotypes(I, J and Q) and III harbored only 2genotypes(N and F). Type N and Fsynchronously presented in Ia and III. In summary, the genetic diversity of tilapia GBS varied by serotypes and changed with geographical locations and years.Although Iastillpredominated, new rareserotypeIII alreadyoccurred in China.  相似文献   

14.
Growth hormone (GH) and reproduction: a review   总被引:5,自引:0,他引:5  
Interaction between growth and reproduction occurs in many vertebrates and is particularly obvious at certain stages of the life cycle in fish. Endocrine interactions between the gonadotropic axis and the somatotropic axis are described, the potential role of GH being emphasised. A comparative analysis of these phenomena in mammals, amphibians and fish, suggests a specific role of GH in the physiology of puberty, gametogenesis and fertility. It also shows the original contribution made by studies on the fish model in this field of investigations.  相似文献   

15.
Protein and amino acid composition of the mantle of juvenile O ctopus vulgaris (Cuvier, 1797) during fasting for 27 days were determined. Average protein content of octopus mantle was of 711.19 ± 46.80 g kg?1 DW, and it decreased with increasing fasting days. The non‐essential amino acids content was higher (486.18 ± 11.08 g kg?1 protein) than essential amino acids (425.82 ± 9.15 g kg?1 protein) at the start of the experiment (unstarved animals). The results suggest that the amino acid profile of the mantle where the most abundant amino acids are Arg, His, Lys, Gly, Leu and Pro could indicate a prolonged fasting condition (>20 days) or poor nutrition of O . vulgaris. This study supports the idea of using mantle for metabolic needs of starved O . vulgaris suggesting that the degradation pathway of amino acids to pyruvate and tricarboxylic acid cycle intermediates was favoured contrary to the degradation pathway of ketogenic amino acids. Special considerations should be taken concerning Thr, Ile, Ser, Ala, Asx (Asp, Asn), Glx (Glu, Gln) (because of their fast intake) and Lys and His (due to their stable contents) during a prolonged period of fasting.  相似文献   

16.
In this experiment, a feeding trial was performed to determine the effects of fructooligosaccharide (FOS) on growth performance, digestive enzyme activity and immune response of Japanese sea bass, Lateolabrax japonicus juveniles (initial weight 38.3 ± 0.5 g), and the fish were examined following feeding with six levels of FOS (0, 0.5, 1, 2, 4 and 6 g/kg) for 28 days. Significant enhancement of weight gain (WG) and specific growth rate (SGR) was found in fish fed 1 g/kg FOS incorporated diets (p < .05), while the feed conversion ratio (FCR) in the 1, 2 g/kg FOS groups reduced significantly compared with the control (p < .05). Besides, the crude lipid in the 4, 6 g/kg FOS groups increased significantly compared with the control (p < .05). On the other hand, the erepsin and lipase activities significantly elevated in intestine of fish fed 2 g/kg FOS (p < .05) and the lysozyme activity in serum of fish fed 2 g/kg FOS were significantly higher than that in the control (p < .05). Moreover, the alkaline phosphatase activities in serum of fish fed 0.5, 1, 2 g/kg FOS were significantly higher than in control (p < .05). Regression analysis showed that the relationships between dietary FOS levels and either SGR, FCR, erepsin or lysozyme activities were best expressed by regression equations, and the optimal inclusion levels are 1.37, 1.80, 3.06, 3.11, 1.93 and 1.80 g/kg for SGR, FCR, erepsin, lipase, lysozyme and total superoxide dismutase activities, respectively. Overall, this study revealed that FOS incorporated diets could beneficial for L. japonicus culture in terms of increasing the growth, digestion and immune activities. Under the present experimental condition, the optimal supplementary level of FOS in the diet of L. japonicus is 1–3 g/kg.  相似文献   

17.
Two gonadotropins (GtH; Qa and Qb) were purified by gel filtration and ion exchange chromatography from the pituitaries of Indian walking catfish (Clarias batrachus). The presence of GtH during purification was assessed by in vitro oocyte maturation and in vivo steroidogenic activity, and their identities were determined by elution profiles, molecular weight, biological activities and yield. The molecular weights of Qa and Qb were 37 and 42 kDa, respectively, and composed of distinct subunits (Qa: 20 and 14 kDa and Qb: 26 and 18 kDa). Polyclonal antibodies raised against Qa immunostained Qa, Qb and pituitary GtH cells. A competitive Qa‐ELISA was developed whose sensitivity was 6.25 ng mL?1 (1.25 ng well?1) with intra‐ (3.5%) and inter‐ (12.4%) assay coefficients of variation. Displacement curves parallel to the standard were obtained with plasma and pituitary extracts of catfish, Qb and carp GtHII. The assay was validated by measuring the plasma Qa levels after LHRH treatment and in relation to ovarian growth in the female catfish during different reproductive phases. Based on the results, Qa and Qb corresponded to fish LH and FSH respectively. The findings will increase the knowledge of the mechanisms controlling fish reproduction and identification of sensitive phases in fish in captivity for hormonal manipulation.  相似文献   

18.
19.
The endemic, anadromous cyprinidChalcalburnus tarichi is the only fish species known to occur in alkaline Lake Van (Eastern Anatolia, Turkey). EightC. tarichi were maintained individually in Lake Van water (17 – 19°C; pH 9.8; 153 mEq·I–1 total alkalinity; 22 total salinity) and tank water samples analyzed for 24 h in 2 to 4 h intervals. At zero time, < 1µM ammonia was present and urea was undetectable in the tank water; at 24 h, total ammonia and urea made up 114±32 and 35±25µM, respectively. Over the experimental period, ammonia-N and urea-N excretion averaged 1041±494 and 607±169moles·kg–1 fish·h–1, respectively. The extent of urea excretion was highly variable between specimens. Uric acid excretion was not detectable.Urea was present at high concentrations in all tissues and plasma (25 – 35moles·g–1·ml–1) of freshly caughtC. tarichi; total ammonia content of the tissues was by a factor of 1.9 (liver) to 3.0 (brain) lower. High arginase activity (2.4±0.2 U·min–1·g–1) was detected in the liver ofC. tarichi but ornithine carbamoylphosphate transferase, a key enzyme of the ornithine-urea-cycle, was absent. Ureagenesis is likely through degradation of arginine and/or uricolysis. High glutamine synthetase activity (11±0.6 U·min–1·g–1) and low ammonia content in brain suggest that, like other teleosts,C. tarichi has an efficient ammonia detoxification in the brain, but in no other tissue.Nitrogenous waste excretion at alkaline pH is discussed. The ability ofC. tarichi to excrete high levels of ammonia at extremely alkaline pH is unique among teleosts studied so far. The mechanism of ammonia excretion under Lake Van conditions remains to be elucidated.  相似文献   

20.
Tetrahymena is a protozoan parasite, which infects guppy, Poecilia reticulata Peters, and causes substantial economical losses in commercial farms worldwide. Studies of guppy infected by Tetrahymena require standardized infection protocols. The LD50 for Tetrahymena infection of guppies by intraperitoneal (IP) injection was calibrated, and the level obtained was 946 parasites per fish. Guppy infection with Tetrahymena by immersion, imitating the natural route of infection via the integument, was studied under normal or stress conditions. Exposure to cold and netting (CNI) and to cold only (CI) followed by immersion exposure to 10 000 Tetrahymena per mL resulted in 22.5% and 19.2% mortality, respectively, as compared to 14.2% and 10% in groups that were netted only (NI) or non‐stressed (I). Histopathology revealed that immersion infection resulted in a systemic infection. Lysozyme levels, measured 3 weeks after infection, were significantly higher in the CNI group (288 μg per mg protein) compared with CI‐, NI‐ and I‐treated groups (94.5, 64 and 62.3 μg mg?1, respectively). There was no evident parasite immobilization activity in body homogenates, suggesting no development of acquired immunity. Re‐infection by IP injection revealed no increase in protection in any of the treatment groups, mortality range of 56.3–75%, higher than in the non‐exposed control (40.6% mortality).  相似文献   

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