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701.
Y. K. Ip S. F. Chew C. Y. Lee W. P. Wong A. L. L. Lim D. H. Murphy 《Marine Biology》1993,116(1):103-107
Onchidium tumidium, an intertidal pulmonate, has evolved to depend mainly on the formation of succinate, rather than lactate and opines, to survive in anoxia. For our study O. tumidum were collected from the mud flats of the mangrove swamp at Mandai, Singapore between 1988 and 1991. After 24 h of anoxic exposure, the lactate and succinate contents of the anoxic individuals were approximately 10 and 150 times, respectively, the corresponding values of the normoxic individuals. Alanine and acetate accumulations also occurred during anoxia, though to a much lesser extent. No propionate or octopine was detected. The depletion in aspartate content in O. tumidium could not account for the amount of succinate accumulated during anoxia. The succinate formed might have originated from glycogen involving the flow of carbon through the phosphoenolpyruvate (PEP) branch point of glycolysis. In support of such a hypothesis, results indicate that there was a decrease in the affinity of pyruvate kinase from O. tumidium exposed to 24h of anoxia to PEP to facilitate succinate formation through phosphoenolpyruvate carboxykinase (PEPCK). In comparison, the affinity of PEPCK from O. tumidium exposed to anoxia to PEP was apparently unaltered. 相似文献
702.
Specimens of the mudskipper Boleophthalmus boddaerti, collected along the estuarine canal at Pasir Ris, Singapore between April 1987 and December 1989, were examined in the laboratory. After being exposed to environmental hypoxia for 6 h, no accumulation of lactate, alanine or succinate was observed in the muscle tissue of B. boddaerti. In addition, the blood lactate content and muscle creatine phosphate (CrP), adenosine triphosphate (ATP) and glycogen contents were not significantly different from those of the control. During normoxic recovery, oxygen debt repayment was only a small fraction of the oxygen deficit incurred during the 6 h of hypoxic exposure. Therefore, it would appear that B. boddaerti coped with environmental hypoxia by undergoing metabolic rate reduction. After anoxic exposure, the CrP, ATP and adenosine diphosphate (ADP) contents in the muscle tissue of B. boddaerti were significantly lower than the corresponding control values. Lactate accumulated in the blood and muscle tissue of the anoxic fish though the muscle energy charge and glycogen content remained constant. Hence, B. boddaerti was able to cope with such a period of anoxia without increasing its glycolytic rate. Succinate, which was not detected in the muscle tissue of the control and hypoxia-exposed fish, accumulated in significant quantities in the muscle tissue of B. boddaerti exposed to environmental anoxia and functional hypoxia. In the case of functional hypoxia, there was a significant decrease in the muscle glycogen content, and the muscle lactate content increased 17.3-fold, indicating that glycolysis was activated to provide the source of energy during muscular exercise. 相似文献
703.
本研究是以占地6公顷,日处理污水1400m~3的渗滤型芦苇湿地实验工程为依托,采用静态模拟与工程运转相结合的方法,着重对污水湿地处理系统BOD_5的生物降解模型进行研究,建立了确定Q值和K_T值的方法,提出了适于天津渗滤湿地系统的Q值和K_T值,为湿地系统设计提供了重要的科学依据. 相似文献
704.
对分布于珠江河口区海域的翡翠贻贝有机氯农药和多氯联苯的含量进行测定 ,结果显示 :HCHs为ND— 1.1ng·g-1,DDTs为 9.5— 191ng·g-1,PCBs为 82 .8— 6 15 .1ng·g-1.尖沙嘴码头 (维多利亚港 )贻贝积累的PCBs浓度最高 ,珠江河口桂山岛和外伶仃岛的贻贝积累的DDTs和PCBs浓度较高 ,而荷包岛 (珠江河口西海区 )的贻贝则检出含量较高的HCHs和DDTs .贻贝选择性积累含 5— 6个氯原子数的PCB异构体 .各采样点贻贝积累的PCBs组成分析表明珠江河口区海域存在两个PCBs污染源 相似文献
705.
A novel respirometer for biological toxicity tests 总被引:2,自引:0,他引:2
AnovelrespirometerforbiologicaltoxicitytestsZhangMinquan,ChenHuanqinChemicalEngineeringResearchInstitute,SouthChinaUniversit... 相似文献
706.
根据水质预测结果用组合规划的方法对长江,嘉陵江重庆干流段和城区段的水污染控制提出了多个不同的方案,并对各方案进行了比较,从水质,经费和施工的可行性3个方面综合评定,筛选出优先考虑方案,同时对方案实施后的效益作出了简要的叙述。 相似文献
707.
708.
Green oysters caused by copper pollution on the Taiwan coast 总被引:1,自引:0,他引:1
The first case of green oysters (Crassostrea gigas) broke out along the Charting mariculture area of south-western Taiwan in January 1986. The green color was found to be due to high copper content in the oyster tissue. Since then, a long-term survey around this area shows that total dissolved copper ranges from 4.99 to 23.6 microg/liter and particulate copper ranges from 1.09 to 5.51 microg/liter in sea-water. The green oysters collected from the Erhjin Chi estuary on 26 January, 1989 gave the highest copper content, 4401+/-79 ppm dry wt. Other green oyster cases were occasionally observed in the Hsiangsan and Anpin mariculture areas. Meanwhile, an experiment of copper accumulation in oysters was conducted at three stations (south-western Taiwan) for up to 90 days. Multiple regression analysis indicates that the food pathway may predominate in copper accumulation by green oysters. This bioaccumulation experiment shows that the total uptake of copper per oyster is an exponential function of exposure time for the first 2 weeks with an accumulation rate of 214 ppm Cu/day and then levels off. The average values of concentration factors for oysters (about 5 x 10(5)) were very close to steady-state values under the natural conditions at each station. 相似文献
709.
Use of cattails in treating wastewater from a Pb/Zn mine 总被引:2,自引:0,他引:2
This article describes the use of a combined treatment system, which includes an aquatic treatment pond withTypha latifolia Linn. (Typhaceae) as the dominant species and a stabilization pond, to treat the wastewater from a Pn/Zn mine at Shaoguan,
Guangdong Province, China.
In 1983, it was noted thatT. latifolia bloomed in areas affected by the wastewater emitted from the mine, hence a combined purification system was subsequently
built.
The influent contained high levels of total suspended solids (4635 mg/liter), chemical oxygen demand (14.5 mg/liter) as well
as Pb (1.6 mg/liter) and Zn (1.9 mg/liter). The results of the effluent after treatment showed that the total suspended solids,
chemical oxygen demand, Pb, and Zn had been reduced by 99%, 55%, 95%, and 80% respectively. The results of plant tissue analysis
indicled thatT. latifolia assimilated significant amounts of Pb and Zn, especially in the root portion.
During 1986 several species of algae and fish were present in the pond, usually with a higher density in areas containing
lower metal concentrations in the water.
Paper was presented in part at the conference “The Use of Constructed Wetlands in Water Pollution Control” held 24–28 September
1990, Cambridge, UK. 相似文献
710.