利用蚕豆根尖微核技术监测韶关市区河段水质的研究

利用蚕豆根尖细胞微核技术监测韶关市区河段水质污染状况,测定6个断面水样的蚕豆根尖细胞微核千分率(MCN‰)及污染指数(PI),并进行F检验。结果表明,各断面水样均能引起微核率升高,孟洲坝、曲江桥、武江桥、高桥、长坝和十里亭断面的微核率分别为10.73‰、7.94‰、5.98‰、5.85‰、5.78‰、4.45‰,PI分别为3.04、2.25、1.69、1.66、1.64、1.26。按照污染指数划分标准,十里亭断面基本没有污染,武江桥、高桥和长坝断面均为轻度污染,孟洲坝和曲江桥断面属于中度污染。表明除十里亭断面外,其余各断面均有不同程度的污染。     

表面活性剂、酸雨和Cd2+复合污染对蚕豆胚根细胞核的毒性

用蚕豆根尖微核技术研究了Cd²⁺单因子以及与表面活性剂、模拟酸雨复合污染时对植物细胞的毒性作用.结果表明,Cd²⁺浓度在0～10.0mg·L^-1范围内,对蚕豆胚根细胞微核的形成有强烈的诱导作用,Cd²⁺浓度6.0mg·L^-1时的细胞微核率为13.85‰,对照组的微核率为4.53‰,此时污染影响指数(PI)为3.06;当环境中存在表面活性剂LAS1.0mg·L^-1或pH值降到4.5和3.5时,同一Cd²⁺浓度下,蚕豆根尖细胞微核率、PI降低,同时伴有核变形,细胞中颗粒物增多,胚根组织不容易分散等症状,根的生长受到抑制,说明表面活性剂、酸雨对Cd²⁺的毒性有协同作用.pH3.5的酸雨环境中Cd²⁺对蚕豆细胞的损伤程度比pH4.5酸雨环境高.在检测高浓度、强毒性污染物的致突变效应时,应作至少3个稀释倍数,找出蚕豆根尖细胞最高微核率及PI.     

SO2对蚕豆根尖和叶尖细胞遗传损伤作用的研究

采用微核实验技术,研究大气污染物SO2对蚕豆根尖和叶尖细胞的遗传损伤效应。结果表明2.80和28 mg.m-3的SO2熏气可以诱发蚕豆根尖和叶尖细胞损伤,导致根尖细胞有丝分裂指数下降,根尖和叶尖间期细胞微核率增高,并具有时间效应和浓度效应。经水恢复培养后,根尖分裂细胞数增多,微核率降低,说明恢复培养能够缓解高浓度SO2对根尖细胞的遗传损伤。用石蜡层隔断SO2在根部水中的溶解后,根尖细胞微核率低于叶尖细胞微核率,而在非隔断组中则相反,说明SO2在水中的溶解是产生毒性效应的重要原因。高浓度SO2熏气对蚕豆根尖和叶尖细胞具有遗传学毒性,由于根尖分生区具有较高的分裂指数和微核率,对环境SO2毒性的反应更灵敏,蚕豆根尖微核实验更适于对环境SO2的监测。     

蚕豆微核技术监测有机废水的遗传毒性

利用蚕豆根尖细胞微核技术研究有机废水对蚕豆根尖细胞的遗传损伤效应。结果表明:不同稀释梯度的实验室废水对蚕豆根尖细胞的有丝分裂指数、微核千分率及污染指数影响不同,并存在一定的差异。     

SO2对蚕豆根尖细胞微核的诱导作用

应用蚕豆根尖微核试验,对SO2的遗传毒性效应进行了研究。结果表明：一定浓度范围内（0.108-14.00mg/m^3）,蚕豆根尖微核细胞数与SO2浓度间呈正相关,太原市大气污染严重的冬季采暖期根尖细胞微核率明显高于非采暖期;SO2浓度0.604mg/m^3处理24h和48h或2.80-28.00mg/m^3熏气处理4h可使蚕豆根尖中具有微核的细胞数明显增加,结果表明,低浓度SO2较长时间接触或高浓度短期接触均可引起蚕豆根尖细胞遗传物质的损伤,应用蚕豆根尖细胞微核实验可对大气SO2污染进行生物监测。SO2（2.80-28.00mg/m^3）熏气实验中,接触时间延长能导致根尖细胞微核率下降,2.80mg/m^3熏气组下降较快,14.00mg/m^3熏气组下降较慢,研究结果提示,在运用蚕豆根尖微核实验监测环境SO2污染时要考虑蚕豆的染毒方式,避免假阴性结果的出现。     

甲硝唑诱导蚕豆根尖细胞微核的研究

本实验研究了甲硝唑诱导蚕豆根尖细胞微核的效应。实验表明：(1)浓度为0.1、6、12、40和500 mg/L甲硝唑均能使蚕豆根尖细胞微核率显著增加,且蚕豆根尖细胞微核率和甲硝唑浓度之间存在明显的剂量-效应关系;(2)甲硝唑能引起DNA损伤,具有分子诱变剂的性能。     

初生根长度对蚕豆根尖细胞微核率影响的研究

研究了不同长度蚕豆初生根微核率的差异,结果表明,初生根越短微核率越低,初生根越长微核率越高,提示蚕豆根尖细胞微核是可积累的,细胞分裂次数越多微核率越高,从而对蚕豆根尖微核测试的可靠性提供理论参考。     

重铬酸钾对蚕豆根尖细胞致畸效应的研究

以蚕豆根尖为材料,研究重铬酸钾对蚕豆根尖细胞的致畸效应。采用蚕豆根尖细胞的微核试验和染色体畸变试验方法,以不同浓度的重铬酸钾为诱变剂,测定蚕豆根尖细胞的微核率和染色体畸变率。结果表明:重铬酸钾能诱发较高频率的微核率,即在一定浓度范围内,其微核率随重铬酸钾处理浓度的升高而增加,但高于一定浓度后反而呈下降趋势;不同浓度的重铬酸钾均使蚕豆根尖细胞有丝分裂指数增大;重铬酸钾还能诱导蚕豆根尖细胞产生较高频率的染色体畸变,且产生多种类型的染色体畸变。结论是重铬酸钾对蚕豆根尖细胞具有明显的致畸效应。     

褐藻寡糖抗环磷酰胺诱导蚕豆根尖的细胞遗传毒性

采用蚕豆根尖细胞的微核试验和染色体畸变试验方法,测定不同浓度的褐藻寡糖对环磷酰胺(cyclophosphamide,CP)诱导的蚕豆根尖细胞的微核率、有丝分裂指数和染色体畸变率的影响。结果表明:褐藻寡糖能有效抑制环磷酰胺诱导的蚕豆根尖细胞微核的产生,即在一定浓度范围内,微核率随褐藻寡糖处理浓度的降低而减少,但低于一定浓度后反而呈上升趋势;不同浓度的褐藻寡糖均可使蚕豆根尖细胞有丝分裂指数增大;褐藻寡糖还能有效降低蚕豆根尖细胞染色体畸变率。因此,褐藻寡糖对蚕豆根尖细胞具有明显的诱抗活性和调节细胞分裂生长的效应。     

SO2对蚕豆根尖和叶尖细胞遗传损伤作用的研究

采用微核实验技术,研究大气污染物SO₂对蚕豆根尖和叶尖细胞的遗传损伤效应。结果表明2.80和28 mg·m^-3的SO₂熏气可以诱发蚕豆根尖和叶尖细胞损伤,导致根尖细胞有丝分裂指数下降,根尖和叶尖间期细胞微核率增高,并具有时间效应和浓度效应。经水恢复培养后,根尖分裂细胞数增多,微核率降低,说明恢复培养能够缓解高浓度SO₂对根尖细胞的遗传损伤。用石蜡层隔断SO₂在根部水中的溶解后,根尖细胞微核率低于叶尖细胞微核率,而在非隔断组中则相反,说明SO₂在水中的溶解是产生毒性效应的重要原因。高浓度SO₂熏气对蚕豆根尖和叶尖细胞具有遗传学毒性,由于根尖分生区具有较高的分裂指数和微核率,对环境SO₂毒性的反应更灵敏,蚕豆根尖微核实验更适于对环境SO₂的监测。     

有机磷农药生产废水氧化塘处理的静态和动态模拟试验

马拉硫磷、对硫磷、乐果、二甲基二硫代磷酸酯和二乙基硫代磷酸酯在藻菌共生系统中是可以被分解的,它们的半分解期分别为2、5、2、42和62天。氧化塘模拟试验结果指出,废水中TOC、COD、和有机磷的去除率分别为65.1%、68.7%和67.8%。根据试验,提出了采用多级串联氧化塘处理葛店化工厂农药废水的参数以及控制鸭儿湖地区污染的方案。       

Genotoxic effects of volatile organic compounds in a chemical factory as evaluated by the Tradescantia micronucleus assay and by chemical analysis

The clastogenic effects of volatile organic compounds in the workplace air of a chemical factory were studied by means of the Tradescantia micronucleus (Trad-MCN) assay and chemical analysis. Sampling was performed at a chemical factory producing PVC film in Cheong-ju, South Korea. Inflorescences of Tradescantia BNL 4430 were placed for 2, 6, and 9 h at the height of 1.40 m at two locations in the workplace and one outdoor of the chemical industry. Air samplings were conducted in the same places and the collected tube samples were analyzed by automatic thermal desorption/gas chromatography/mass spectrometry (ATD/GC/MS). The frequencies of micronuclei in specimens exposed for 2 h in sites 1-3 were 6.13 +/- 0.47, 5.40 +/- 1.60, and 2.93 +/- 0.43 MCN per 100 tetrads, respectively. GC/MS analysis proved the presence of various volatile organic compounds such as trichloroethylene, toluene, ethyl benzene, (m, p, o)-xylene, styrene, 1,3,5-trimethyl benzene, and 1,2,4-trimethyl benzene. Mean values of toluene measured by 2 h sampling in sites 1-3 were 1946.6, 1368.3, and 340.1 microg/m3, respectively. The toluene concentrations in sites 1 and 2 were at least four to six times higher than that in site 3. The micronucleus frequencies increased with exposure time. In addition, there was a correlation between the micronucleus frequencies and toluene concentration in the air (R2 = 0.96). The results of this in situ monitoring proved the applicability of the Trad-MCN assay combined with chemical analysis for monitoring genotoxic chemicals in the work environment.     

应用微核技术对北京三海水域污染状况的研究

2003和2004年于北京三海（西海、后海和前海）分别采集21、22个样品,利用蚕豆根尖微核技术对水体的污染状况进行了遗传毒性分析。结果表明,水体总体显示出不同程度的遗传毒性特征。2003、2004两年中,微核相对率〈1．5的样本分别占4．7619％、18．1818％,主要分布于前海和后海湖心区域;微核相对率为1．5～2．0的样本分别占28．5714％和13．6364％;微核相对率为2．0～3．5的样本分别占28．5714％和45．4545％;微核相对率〉3．5的样本分别占38．0952％和22．7273％。其中。在民居密集的西海区域,两年重度污染率均达到40％。结果表明,水体污染程度与人为因素具有显著相关。本文对试验方法亦进行了讨论。     

Performance of constructed wetlands in the reduction of cadmium in a sewage treatment cum fish farm at Kalyani, West Bengal, India

The distribution pattern of cadmium was investigated in waste stabilization ponds designed for three-step sewage treatment processes. The overall mean concentration of cadmium in water and sludge was reduced by 30% and 33%, respectively, from the inlet of the anaerobic pond to the final outlet of the maturation pond. The level of cadmium in water hyacinth, plankton and fish remained higher in all the samples collected from the anaerobic or facultative pond compared to the last maturation pond. It may be reasonable to conclude that three-step ecological treatments accompanied by physical, chemical and biological processes of the waste stabilization ponds were effective in reducing the load of cadmium from sewage effluents.     

Micronuclei,nuclear lesions and interphase silver-stained nucleolar organizer regions (AgNORs) as cyto-genotoxicity indicators in Oreochromis niloticus exposed to textile mill effluent

In this study, cyto-genotoxic effects of a textile mill effluent on fish Oreochromis niloticus were investigated using the micronucleus (MN) test and methods to analyze interphase silver-stained nucleolar organizer regions (AgNORs). Fishes were exposed to three different concentrations of textile mill effluent (5, 10 and 20%(v/v)) for 3, 6 and 9 days. Cyclophosphamide (2mg/l) was used as a positive control. Micronucleus frequencies were examined in peripheral blood erythrocytes and gill cells. Nuclear abnormalities (NA) other than micronuclei such as binuclei, lobed nuclei, blebbed nuclei and notched nuclei were also evaluated in peripheral erythrocytes. Interphase AgNOR parameters were examined in epithelial cells obtained from the edge of caudal fins after 90 and 180min of exposure. As a result, dose-dependent increases in the frequencies of micronuclei and other NA in erythrocytes were observed. MN frequencies in gill cells also significantly increased, while the interphase AgNOR parameters in fin cells decreased, as a result of textile effluent and cylophosphamide treatments.     

The efficiency of a closed-loop chemical-free water treatment system for cyprinid fish farms

The study presented has been carried out to evaluate the treatment performance, fish production and water consumption of a closed-loop chemical-free water treatment system for small-scale cyprinid fish farms. The closed-loop system consisted of a 36 m³ experimental pond (Pond A) with initial carp load of 1 kg/m³ (34 Cyprinus c. carpio); of a treatment train (TT) with a roughing filter (RF), glass fibre filters (GFF), and UV-C units (UV); and of an ultrasound unit (US) installed in the corner of the pond. The average circulation of the water in the closed-loop system was 2.3 times per day. Pond A was compared with a control pond (Pond B) of the same dimensions and fish load but with no TT or US. The TT was efficient in the removal of total suspended solids, biochemical oxygen demand, chemical oxygen demand, total coliforms (TC), and faecal coliforms (FC), reaching 35%, 42%, 33%, 37%, 91% and 91% removal, respectively. The majority of pollutant removal took place in the RF, while the GFF contributed mostly to the removal of TC and FC. UV did not contribute to the removal of bacteria, mostly due to low TC and FC inputs. The removal of nutrients in the TT (ammonia, nitrites, nitrates, total phosphorous and orto-phosphate) was not efficient. Despite this, Pond A had markedly lower nutrient concentrations compared to Pond B, and all the mean values of the measured parameters except nitrites and total phosphorous in Pond A were below legislation limit. Specific growth rate and fish body weight increase in Pond A were higher than in Pond B (0.3%/day, 0.2%/day, 152% and 115%, respectively) indicating better rearing conditions in Pond A. However, fish showed with 2.8 in Pond A and 3.3 in Pond B poor feed conversion rate over warm months. Higher water consumption in Pond A was due to various interventions during the pilot operation that can be reduced in normal operation. The results showed that the closed-loop system presented could be useful for semi-natural fish farming of 1-2 kg fish/m³. However, the system should be improved with regular sedimented algae removal to avoid nutrient accumulation.     

Cadmium tolerance and antibiotic resistance in Escherichia coli isolated from waste stabilization ponds

The incidence pattern of cadmium tolerance and antibiotics resistance by Escherichia coli was examined periodically from the samples of water, sludge and intestine of fish raised in waste stabilization ponds in a sewage treatment plant. Samples of water and sludge were collected from all the selected ponds and were monitored for total counts of fecal coliform (FC), total coliform (TC) and the population of Escherichia coli, which was also obtained from the intestine of fishes. Total counts of both FC and TC as well as counts of E. coli were markedly reduced from the facultative pond to the last maturation pond. Tolerance limit to cadmium by E. coli tended to decline as the distance of the sewage effluent from the source increased; the effective lethal concentration of cadmium ranged from 0.1 mM in split chamber to 0.05 mM in first maturation pond. E. coli isolated from water, sludge and fish gut were sensitive to seven out of ten antibiotics tested. It appears that holistic functions mediated through the mutualistic growth of micro algae and heterotrophic bacteria in the waste stabilization ponds were responsible for the promotion of water quality and significant reduction of coliform along the sewage effluent gradient.     

由气单胞菌的一个新种引起的一次爆发性鱼病的病原学研究

本文报告1988年夏季对北京地区一次爆发性鱼病病原学研究的结果。从病鱼脏器和池塘疫水中分离到革兰氏阴性杆菌,其中氧化酶阳性菌株占75.6%,大多数为溶血性菌株,而不发病鱼池的健康鱼中氧化酶阳性菌株为0.1～1%,详细的生化检定证明这些细菌为气单胞菌,且为同一血清型,但不同于现已报告的亲水气单胞菌,豚鼠气单胞菌,温和气单胞菌,凡隆气单胞菌和舒伯特气单胞菌,而为气单胞菌的一个新种。流行病学资料与实验感染健康鱼发病成功,证明该菌是这次鱼病的病原菌。     

Influence of the fish pond aquaculture effluent discharge on abiotic environmental factors of selected rivers in Northwest Poland

Pollution of rivers caused by human activity is a widely discussed problem, however there is not much attention paid to the changes of water quality that result from the inflow of effluent discharged from fish breeding ponds. The paper presents results of studies on changes of the abiotic parameters (hydrochemical and hydrological) of water observed in the yearly cycle between 2004 and 2008 in selected rivers of Northwest Poland. It was proved that the fastest reaction on the inflow of the effluent discharged from the fish ponds was reflected in changes of biogenic and organic compounds in the river water. The largest, i.e. threefold (rivers Krapiel and Tywa) or even fourfold (rivers Rurzyca and Stepnica) increase in nutrients and organic matter was recorded during the pond effluent discharge into the rivers. At that time values of the organic matter ranged from 8.9 to 18.3 mgO₂/dm³ (BOD₅), the nitrogen compounds from 16.868 to 26.930 mgN/dm³, while the phosphorus from 1.928 to 6.353 mgP/dm³. Interestingly, an additional dry mass of seston was recorded no earlier than the activity of the harmful element had been stopped and the river had resumed to the “initial” state (i.e. before the effluent discharge); that period varied from one to two months, depending on the river characteristics. The highest values of the dry seston mass (580.9 mg/dm³) was recorded in river Krapiel in November 2006. It seems that in spite of remarkable influence on values of individual physical and chemical indices of the river water quality, the effluent discharge from the fish ponds is not a factor hampering the self-purification processes of the rivers.     

Biological Control of Culex pipiens pattens (Diptera, Culicidae) by the Release of Fish Muddy Loach, Misgurnus mizolepis in Natural Ponds, Korea

ABSTRACT An assessment on the biological control potential with the fish muddy loaches (Misgurnus mizolepis) was conducted against naturally bred Culex pipiens pollens larvae in four ponds (A, B, C and D) in Busan from July through September, 2001. Predation of the fish at 3 different release rates of 4,5, and 6 fish/m² resulted in mostly over 90% mosquito control from the first week after treatment through the end of the survey period for 11 weeks. There were no significant difference among the release rates of fish at the 5% level of probability. However, substantial controls of 43.0% and 25.9% were obtained from pond C during the 3rd and 7th weeks after the fish introduction, respectively. The results of those two weeks showed a lower biological control by the introduced larvivorous fishes. This might be due to the presence of heavy organic matters including aquatic weeds and/or severely polluted water from sewage in pond C. The aquatic weeds covered the pond's water surface which may have affected the deterioration of mosquito preying in favor of aquatic weeds. Also, the fishes were observed to avoid severely contaminated sewage water in some parts of ponds A and C where more mosquito larvae were found.