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1.
为研究甘蔗渣作为载体填料用于海水曝气生物滤池中的可行性,在海水曝气生物滤池中培养生物膜,并以此为基础构建海水养殖排放水处理系统。通过监测水体总氨氮(TAN)、亚硝酸盐氮(NO2--N)等水质指标浓度变化,水体游离细菌与载体附着细菌密度变化,评价甘蔗渣载体生物滤池的降解效果。结果显示,以甘蔗渣为载体的生物滤池挂膜所需时间为26 d,挂膜完成后甘蔗渣附着可培养总菌和芽孢杆菌密度分别为3×108cfu/g和7.8×107cfu/g。在处理养殖水体时,生物滤池中水体氨氮和亚硝酸盐氮浓度分别控制在0.2 mg/L和0.05 mg/L以下,同时,水体中芽孢杆菌数量由3.3×103cfu/L增加至7×104cfu/L,弧菌数量由4.9×103cfu/L下降至3.1×101cfu/L。研究表明,以甘蔗渣为载体的海水曝气生物滤池能快速有效地完成挂膜,并在海水养殖排放水处理中取得较好效果。  相似文献   

2.
为提高对虾养殖系统水质净化能力,改善对虾养殖水环境,利用3种微生态制剂(枯草芽孢杆菌、硝化细菌、光合细菌)和2种生物膜载体(陶粒、纤维毛球)建立4个南美白对虾(Penaeus vannamei)养殖系统,比较不同养殖系统硝化功能的建立过程及对氨氮和亚硝酸盐氮的净化能力,采用高通量测序方法分析细菌群落结构。结果表明,各系统硝化功能建立后,24 h氨氮去除率较初期分别提高12.47%、13.95%、17.25%和17.65%。以纤维毛球为载体,投加硝化细菌、枯草芽孢杆菌和光合细菌系统的氨氧化能力和亚硝酸盐氧化能力强于陶粒系统,24 h氨氮去除率分别高9.03%和9.06%。投放虾苗后,在30 d养殖周期内,各系统氨氮和亚硝酸盐氮含量分别维持在0.20 mg/L和0.15 mg/L以下,硝酸盐氮含量呈缓慢上升趋势。细菌群落结构分析表明,养殖系统生物膜中优势菌门均为变形菌门,占比超40%;优势菌纲为α-变形菌纲、β-变形菌纲、γ-变形菌纲,系统中存在Nitrosomonas、Nitrospira和Nitrococcus等多种参与水体净化以及Algisphaera、Gemmatimonas和Paucibacter等参与有机质分解与对虾益生作用的类群。本研究可为减少养殖水体废物排放及降低水生环境污染风险提供参考。  相似文献   

3.
固定床生物膜反应器(fixed-bed biofilm bioreactor, FBBR)和移动床生物膜反应器(moving- bed biofilm reactor, MBBR)在养殖水体氨氮(NH4+-N)和亚硝酸氮(NO2–-N)污染控制中已有较为广泛的研究,然而相关研究大多是在实验室完成的,目前尚缺乏实际生产的循环水养殖系统(recirculating aquaculture system, RAS)中FBBR和MBBR水体净化效能的对比研究。因此,本研究将FBBR (弹性毛刷滤料)和MBBR (PVC多孔环滤料)并联接入实际生产的墨瑞鳕(Macculochella peeli) RAS中,实现二者的同步连续运行(35 d),考察了其出水水质变化和微生物群落结构。出水水质变化表明,FBBR和MBBR中氨氧化能力的形成快于亚硝氮氧化能力,硝化能力渐趋成熟,可以有效控制养殖水体中的NH4+-N和NO2–-N浓度,但会导致养殖水体中硝酸氮(NO3–-N)积累和pH下降;单因素方差分析表明,FBBR出水中NH4+-N、NO2–-N、NO3–-N浓度和pH与MBBR出水无显著差异,两反应器的硝化效率相似。FBBR和MBBR在微生物群落上的相同点在于:优势菌门为变形菌门(Proteobacteria) (相对丰度分别为69.42%和86.92%),优势菌纲为γ-变形菌纲(γ-Proteobacteria) (40.71%和63.36%)和α-变形菌纲(α-Proteobacteria) (26.58%和21.74%),优势菌属为不动杆菌属(Acinetobacter) (27.50%和53.29%);硝化菌由亚硝化单胞菌属(Nitrosomonas)和硝化螺菌属(Nitrospira)构成;硝化螺菌属的相对丰度远高于亚硝化单胞菌属,两反应器中可能存在完全氨氧化菌。两反应器在微生物群落上的不同点在于FBBR微生物群落的丰富度和多样性以及硝化菌的相对丰度均高于MBBR。本研究可以为RAS养殖水体净化提供技术支撑,助推循环水养殖模式的推广应用。  相似文献   

4.
电气石对硝化菌生长和生物膜形成、熟化的影响   总被引:3,自引:0,他引:3  
在培养基中添加电气石培养硝化菌,研究电气石对硝化菌生长的影响,并在此基础上将电气石添加到普通陶粒(CM)原料中制备了功能性陶粒(FCM),通过测定水中氨氮、亚硝酸盐氮和硝酸盐氮的含量变化,比较功能性陶粒和普通陶粒两种载体上生物膜的生长状况。结果表明:添加电气石的培养基中的亚硝化细菌和硝化细菌数量明显高于未添加电气石的对照组;FCM上的生物膜熟化过程对氨氮的去除率在第14 d趋于稳定,硝酸盐氮含量从第12 d逐渐升高,分别比CM早7 d和6 d,能较早发挥生物硝化功能。  相似文献   

5.
该研究使用碘(I2)、二氧化氯(ClO2)、甲醛溶液(HCHO)和漂白粉[Ca(ClO)2]4种常用消毒剂对凡纳滨对虾(Litopenaeus vannamei)育苗海水处理后,研究了不同发育期育苗水体总菌和弧菌数量、氨氮和亚硝酸氮含量、幼体成活率以及水体和幼体菌群的变化。结果显示:1)甲醛组水体的总菌数较低,且弧菌数量最低;2)4种消毒剂组水体氨氮和亚硝酸盐浓度均低于对照组,其中漂白粉组最低;3)甲醛组幼体成活率显著高于其他各组(P<0.05);4)消毒剂改变了育苗水体和幼体的菌群结构和优势菌丰度,育苗水体菌群组成比幼体更为复杂,且早期阶段比后期复杂。其中,无节幼体(N6)—溞状幼体(Z1)阶段水体优势菌属主要为OM43_clade、食烷菌属(Alcanivorax)、赤杆菌属(Erythrobacter)、交替赤杆菌属(Altererythrobacter)、黄杆菌属(Tenacibaculum)、水栖菌属(Enhydrobacter)、泥滩微菌属(Gilvibacter)等,糠虾幼体(M1)—仔虾(P1)阶段水体中优势菌属有东吉科拉属(Donghicola)、黏着杆菌属(Cohaesibacter)、Phaeodactylibacter、念珠菌属(Candidatus-Cquiluna)和鲁杰氏菌属(Ruegeria),而幼体中的优势菌属有弧菌属(Vibrio)、动性杆菌属(Planomicrobium)、微杆菌属(Exiguobacterium)、嗜冷杆菌属(Psychrobacter)、不动杆菌属(Acinetobacter)、芽孢杆菌属(Bacillus)、嗜甲基菌属(Methylophaga)和盐单胞菌属(Halomonas)。  相似文献   

6.
为了解复合垂直流人工湿地系统对海水养殖尾水中各形态氮的处理效果, 以及植物与不同基质层微生物群落特征的相似性和差异性, 以互花米草(Spartina alterniflora)-细砂-煤渣-碎石构建的复合垂直流人工湿地系统为研究对象, 研究了该系统对海水石斑鱼养殖尾水中 COD、NO3 -N、NO2 -N、NH4 + -N 和总氮(TN)的去除效果, 并采用高通量测序技术分析了植物根际和不同基质层微生物群落特征。结果表明, 复合垂直流人工湿地系统对污染物有较好的去除效果, 出水中 COD、NO3 -N、NO2 -N、NH4 + -N 和 TN 的平均浓度分别为 4.00 mg/L, 0.15 mg/L, 0.16 mg/L, 0.04 mg/L, 0.64 mg/L。植物根际样品和细砂层样品的微生物群落丰富度和多样性较高, 与其他基质层样品具有明显差异; 在门分类水平上优势菌以变形菌门、拟杆菌门、放线菌门、绿弯菌门和厚壁菌门为主, 相对丰度分别为 53.7%、11.5%、11.9%、6.4%、3.7%; 在纲分类水平优势菌以 α-变形菌纲、γ-变形菌纲、放线菌纲和拟杆菌纲为主, 相对丰度分别为 30.1%、20.9%、11.9%、10.3%; 人工湿地中丰度最高的脱氮功能菌包括亚硝化单胞菌属、硝化螺菌属、 芽孢杆菌属、假单胞菌属和不动杆菌属; 系统中微生物代谢功能丰富, 且所有样品功能组成相似; 相同基质层样品的微生物群落组成差异较小, 二级湿地单元各基质层样品微生物群落的差异程度与一级湿地单元相比较小。  相似文献   

7.
本文通过在循环水养殖系统中添加不同浓度的臭氧,研究其对循环水养殖系统生物膜活性及其净化效能的影响.结果显示,当氧化还原电位(ORP)小于450 mV时,氨氮的去除率随着臭氧浓度升高而升高,最高去除率达39.9%,亚硝酸盐氮的平均去除率为28.2%,生物膜菌群的平均存活率为88.1%,生物膜对养殖水体氨氮和亚硝酸盐氮的处理效果良好;当氧化还原电位为500 mV时,经过臭氧24 h处理,氨氮和亚硝酸盐氮的去除率分别由36.5%、28.1%降到12.2%、8.4%,而臭氧4h处理后,生物膜对氨氮和亚硝酸盐氮的去除率分别由47.5%、32.1%降到5.0%、3.3%,水处理效果明显下降,生物膜菌群存活率由88.1%降到31.5%.由此可见臭氧添加浓度对生物膜及净化效能有重大影响.综合试验结果和分析评估,建议封闭循环水养殖系统的臭氧添加量以控制生物滤池内的氧化还原电位低于400 mV为宜,可保证循环水系统的安全性和经济性.  相似文献   

8.
厌氧氨氧化和反硝化作用是底泥生物脱氮的主要过程,碳源是调控厌氧氨氧化和反硝化作用的关键因子。本研究以褐煤为对象,对褐煤的静态碳释情况及其对池塘底泥中脱氮作用的影响进行了研究。结果显示,褐煤在室温条件下的碳释放规律符合二级动力学方程,具备作为反硝化碳源的可行性;在脱氮实验中,发现褐煤对底泥上覆水体中的亚硝酸盐氮(NNO2--N)的去除具有促进作用,NNO2--N的去除率随褐煤浓度的增加而升高,当褐煤质量浓度为40 g/L时,N\${\rm{O}}_2^ - $\-N去除率最高达99.61%,此时硝酸盐氮(NO3--N)的浓度也最低;同时发现,水体中氨氮(NH4+-N)氧化的最适褐煤质量浓度为10 g/L,其去除率达99.39%;对底泥中的厌氧氨氧化菌群进行Illumina高通量测序发现,其中浮霉菌门占比最大(39.6%~71.8%),优势菌属为Candidatus Brocadia (13.9%~35.8%)和Desulfovibrio (17.1%~34.8%),添加褐煤组Candidatus Scalindua菌属比例高于未添加组;荧光定量PCR得出,随着褐煤质量浓度升高,底泥中的反硝化菌丰度呈增长趋势,而厌氧氨氧化菌丰度则低于无褐煤添加组,表明添加褐煤对底泥反硝化有促进作用,而对厌氧氨氧化有一定的抑制作用。研究表明,褐煤具备作为反硝化碳源的条件,可用于池塘养殖底泥脱氮作用。  相似文献   

9.
使用2216E平板涂布法从肠道样品分离可培养细菌,通过16S r DNA测序鉴定细菌。所有分离的细菌分为变形菌门(包含γ-变形细菌纲和α-变形细菌纲)和厚壁菌门。其中以γ-变形细菌纲为优势(83.3%)。在属的水平,从肠道中共分离出弧菌属、希瓦氏菌属、假交替单胞菌属、亚硫酸杆菌属、芽孢杆菌属、Aliivibrio、发光杆菌属、科尔韦尔氏菌属8个属,其中弧菌属、希瓦氏菌属和假交替单胞菌属的种类占总数的70%。首次发现亚硫酸杆菌属和科尔韦尔氏菌属作为红鳍东方鲀稚鱼肠道菌群的一部分。  相似文献   

10.
本实验模拟工厂化养殖模式建立养殖水体净化装置,研究硝化毛球和底沙对硝化细菌净化效果的影响,结果表明:装载硝化毛球、铺设底沙和只投加硝化细菌制剂的三个实验组对养殖水体水质具有一定的净化效果,氨氮、亚硝氮等指标均低于空白组。其中装载硝化毛球的实验组氨氧化细菌、亚硝酸盐氧化细菌可在短时间大量生长繁殖,形成优势,使养殖池氨氮、亚硝酸盐浓度维持在较低水平;铺设底沙的实验组对硝化细菌净化水质效果影响不大。装载硝化毛球的实验组,水质最清澈,无异味,养殖池底部无残渣碎屑,青虾生长状况良好,增重最多。  相似文献   

11.
循环水养殖系统生物滤器负荷挂膜技术   总被引:4,自引:0,他引:4       下载免费PDF全文
循环水养殖系统启动运行前往往需要经过一段时间的生物膜预培养,使生物膜达到成熟稳定,从而保证系统的水质净化功能。本研究通过养殖试验,研究了生物滤器负荷挂膜的技术方法,以期实现生物膜的快速成熟和系统的快速启动。为此,构建了6组循环水系统组成的养殖车间,建成后立即投入试验生产。试验为期120 d,养殖种类为红鳍东方鲀,初始放养平均体重(632.5±2.26)g。期间,红鳍东方鲀平均增重29.91%,养殖成活率98.7%,养殖密度由(19.34±1.89)kg/m3增加到(32.17±3.40)kg/m3,投饵率由0.2%增加到0.5%–0.7%,每日换水量由50%逐渐减至10%。结果表明,在生物膜的生长期,通过对投饵量及新水补充量的有效调节,可以把养殖水体中的氨氮和亚硝氮浓度控制在安全范围以内,以保证养殖鱼类的生长。生物膜在50天左右达到完全成熟,此后便可依靠生物膜的净化作用将氨氮浓度控制在0.5?1.2 mg/L、亚硝氮浓度控制在0.2?0.5 mg/L、pH值控制在6.5–7.5、COD值低于4 mg/L、细菌总数控制在800–2100 cell/ml的安全范围内。利用生物滤器负荷挂膜技术,在合理调控水质指标的条件下,循环水养殖系统建成后可以立即投入生产,实现生物滤器挂膜与养殖生产的同步进行。  相似文献   

12.
对牙鲆(Paralichthys olivaceus)自净式养殖槽水层和过滤沙层的异养细菌和硝化细菌数量及硝化速率进行了研究,测得装有循环过滤装置的水槽水中和沙粒上异养细菌平均数量分别为2.32×10  相似文献   

13.
Gut bacteria may contribute significantly to the growth and survival of cultured shrimp, although little is known about factors that affect bacterial community structure in shrimp guts. The objective of this study was to determine the abundance and species composition of gut bacteria in juvenile white shrimp Litopenaeus vannamei reared in two different environments. Eight 120-L tanks were stocked at a density of 8 shrimphank. Two treatments were tested for 10 d and consisted of tanks receiving flow-through water from one of two sources: 1) well water pumped from a sea-water aquifer (Well treatment), and 2) pond water pumped from an intensive shrimp pond (Pond treatment). Shrimp mid- and hindguts were excised on days 1, 3, 6, and 10 for enumeration of gram-negative, aerobic bacteria by quantifying colony-forming units (CFU) using standard microbiological plating techniques. Identification of bacterial isolates was made using the Biologa® GN Microplate system. Bacterial numbers were significantly greater ( P > 0.05) in Well shrimp than in Pond shrimp on days 1 and 3. Following day 3, a decrease in bacterial numbers occurred in the Well shrimp, and no significant differences between treatments were observed on days 6 or 10. Guts from Well shrimp were dominated by Vibrio and Aero-monas , and these two genera accounted for 80–851 of the bacteria on each sampling day. Guts from Pond shrimp exhibited a greater bacterial diversity and were dominated by Vibrio, Aeromonas , and Pseudomonas. Flavobacterium were identified in the guts of Pond shrimp on days 3 and 10, but were not identified in any of the Well shrimp. A greater understanding of gut bacteria-shrimp interactions could lead to increased production and profitability for shrimp farmers through the development of more cost-effective feeds and novel disease control strategies.  相似文献   

14.
Vibrios are highly motile, facultatively anaerobic bacteria that are ubiquitous in aquatic environments and part of the normal intestinal microflora of healthy fish, but some species can cause vibriosis. The adherence of vibrios to host fish intestines is a significant event not only for their survival and growth, but also in terms of pathogenicity. However, the molecular mechanism underlying the adhesion of vibrios to the intestinal tract of fish is not fully understood. We report here the identification of intestinal glycosphingolipid (GSL) receptors to which pathogenic vibrios attach in typical mariculture fish. Thin-layer chromatography overlay assays using five species of 35S-labeled vibrios and intestinal glycosphingolipids of seven species of mariculture fish revealed that all of the fish tested possessed GM3 (NeuAcα2-3Galβ1-4Glcβ1-1′Cer) and/or GM4 (NeuAcα2-3Galβ1-1′Cer) as major acidic intestinal GSLs and that all of the vibrios tested specifically adhered to GM3 and/or GM4. Our results demonstrate that these GSLs were able to function as a receptor for the various vibrios tested. Analysis of the relationship between sugar structure and receptor activity for vibrios revealed that ‘NeuAcα2-3Galβ1-’ is required at the non-reducing end of glycosphingolipids for the bacteria to attach.  相似文献   

15.
运用平板培养计数法、最大或然数法和16S rRNA 基因的 PCR-DGGE 指纹图谱技术,分析发病刺参池塘环境中不同生理类群细菌数量及群落结构对底质改良剂的响应。结果显示,加入底质改良剂后,发病刺参池塘沉积环境中的总异养菌、硝化细菌、硫酸盐还原细菌等的数量在最初的2–4 d 有所上升,但升高幅度小于对照组,且在之后的2–4 d 内下降至加改良剂之前菌量;在加入底质改良剂后第2天,弧菌和硫化细菌数量便迅速下降,明显低于对照组。PCR-DGGE 图谱及测序结果显示,刺参养殖环境细菌优势菌分别属于绿弯菌门、变形菌门的莫拉菌科、柄杆菌科和气单胞菌科以及厚壁菌门的芽孢杆菌科和乳杆菌科的某种细菌,多样性指数在2.5–3.5之间。实验组加入底质改良剂后,气单胞菌属两种细菌数量逐渐下降。研究结果表明,底质改良剂可改变沉积环境中不同细菌类群的数量,降低致病菌的数量,从而改善底质环境并对“刺参腐皮综合征”起到防治作用。  相似文献   

16.
ABSTRACT: A rapid method to enumerate bacteria adhered on a surimi-based product (kamaboko) by flow cytometry (FCM) is described. To remove Escherichia coli cells from the surface of kamaboko, ultrasonic energy was used. Almost all cells can be removed from kamaboko in 3 min with ultrasonic treatment. Because the sample might contain various non-bacterial particles such as food additives and debris of products, propidium iodide was used to discriminate bacterial cells from non-bacterial particles. Fluorescence scattergrams could distinguish bacteria from the particles, and the FCM method could be used to enumerate bacteria adhered on the surface of kamaboko during storage. Cell numbers determined by FCM paralleled well with those measured using a traditional colony counting method in the range of 104–108 cells/g. The FCM assay could enumerate cells within 1 min and the total assay time, including sample preparation, was less than 30 min.  相似文献   

17.
为研究不同形式湿地中厌氧脱氮菌的分布特征和关键影响因子,选择池塘、沟渠、表流和潜流4种形式湿地,采用16S rDNA克隆文库法和典型对应分析等方法,分析了夏季4种形式湿地中厌氧氨氧化菌和反硝化型甲烷厌氧化菌的菌群结构及其与环境因子的相关性.结果显示,湿地中的AMX菌与Candidatus Brocadia fulgida相似性最高可达99%,DAMO菌与典型菌株C.Methylomirabilis oxyfera分在了不同的分支.夏季4种形式湿地中,AMX菌的Shannon多样性依次为表流湿地>潜流湿地>沟渠>池塘,DAMO菌的Shannon多样性依次为池塘>潜流湿地>沟渠>表流湿地.上覆水中TOC和NO3--N是影响AMX菌分布的主要因素,上覆水中TN、NH4+-N、pH和DO对DAMO菌分布影响最大.研究表明,夏季表流湿地底泥中所含AMX菌类别最多,池塘底泥所含DAMO菌种类别最多,不同形式湿地中均有AMX菌存在,但不确定是否存在DAMO反应,影响2类菌群分布的主要相关因子是C、N以及pH和DO.  相似文献   

18.
Microbiological conditions in 200 L cultures of microalgae Chlorella minutissima in polyethylene sleeves were examined. The influence of addition of antibiotic (nitrofurantoin) was studied. Samples were taken 2, 5, 9, and 14 d after inoculation and were spread on solid Zobell medium and on thiosulfate citrate bile salts sucrose agar for the enumeration of total numbers of bacteria and numbers of presumptive Vibrio bacteria, respectively. Microalgae grew well in the cultures and high numbers of culturable bacteria (about 107 bacteria/mL) were present in all microalgae cultures. Addition of antibiotic in 200‐L cultures of C. minutissima did not result in a significant decrease of total counts of bacteria per unit volume (P > 0.05), while the numbers of presumptive Vibrio were higher in cultures added antibiotic compared with the control treatment (P < 0.05). The numbers of presumptive Vibrio per unit volume and the percentage of fast‐growing bacteria were higher in microalgae supernatant than in noncentrifuged samples. Representative colonies were taken from all samples and in total 649 bacterial strains were isolated during this study. A range of phylotypes was identified by amplification and sequencing of the 16S rDNA gene and phylogenetic trees were constructed. Several members of the Roseobacter clade were dominant among the culturable isolates.  相似文献   

19.
乳山湾东流区细菌数量的分布及与环境因子关系的研究   总被引:1,自引:0,他引:1  
根据1995年6~9月对乳山湾东流区的微生物调查资料,研究了乳山湾东流区海水及底泥中细菌和弧菌量的变化及其与环境因子的关系。结果表明,该海域海水中细菌和弧菌的数量变化与温度的变化相一致,6月中旬~8月中旬,细菌数量增长比较缓慢,8月中旬开始,细菌数量增长较快,到8月底,达到最高值,异养菌为5.71×106cell/mL,弧菌为2.1×104cell/mL。而后,随着温度的下降,水中的细菌量逐渐减少。滩涂底泥中,细菌和弧菌的数量均比海水中细菌高l~2个数量级。  相似文献   

20.
Total organism content of L-thyroxine (T4) and triiodo-L-thyronine (T3) were measured in the early developmental stages of a stock of Lake Ontario coho salmon from the egg to the yolk absorption stage. Whole organism T4 levels were constant between the egg and pre-hatch embryo stages, but fell progressively during yolk absorption. T3 levels were low from egg to eye-pigment appearance, but then increased prior to hatch and fell again during the post-hatch yolk absorption period. When expressed as ng/tissue, T4 content of the body compartment rose progressively between days 67 and 87 post-fertilization, whilst T4 content of the yolk compartment fell progressively during the same period; the pattern was not evident for tissue T3 content. When expressed as ng/g dry weight of tissue, the inverse relationship was found for T4, and T3 content of the body and yolk compartments decreased progressively and increased progressively, respectively during the same period, suggesting that thyroid hormones were selectively retained in the yolk compartment. Intensely “immunostained” (using anti-human β-TSH antibody) thyrotropic cells were present in small numbers in the pars distalis of the embryonic pituitary at the eye-pigment appearance stage, and the numbers increased markedly until the pre-hatch period. Administration of either bovine thyrotropic hormone (bTSH) or ovine growth hormone (oGH) had no effect on thyroid hormone content of larvae challenged during the yolk absorption period, suggesting that the thyroid tissue was not responsive to exogenous bTSH challenge at this time, and that oGH-sensitive 5′-monodeiodination was either not present or at levels that were too low to cause an elevation in total T3 content, or that the substrate levels were insufficient to permit a measureable increase in whole body T3 content.  相似文献   

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