改性原位粘土去除滇池蓝藻

主要综述了滇池的污染现状,并阐述了以往治理滇池污染的方法。通过对滇池的底泥用生物试剂进行改性,并把经过改性后的粘土投入滇池处理蓝藻和污染物,达到了除藻和除氮、磷污染物的双重效果。改性原位粘土方法对滇池水资源的开发利用和环境保护产生积极的作用。     

Influence of level and source of Fe on growth and nutrient content of Euglena gracilis

Abstract

Growth parameters and Fe, Cu, Mn and N status of Euglena gracilis cells were determined as a function of level and source of Fe supply in the nutrient environment. Use of FeEDDHA promoted cell division while FeSO₄·lb7H₂O promoted cell enlargement after 7 days. Greatest N content was present in rapidly dividing as compared to enlarging cells. Copper content was directly related to cell size with larger cells containing more Cu than smaller cells. Manganese uptake was inversely related to Fe supply with FeSO₄·lb7H₂O inhibiting Mn uptake to a greater extent than chelated Fe. Iron uptake increased significantly with the addition of iorganic or chelated Fe. The Fe uptake was comparable from both sources at the 1 ppm Fe level of supply, but much greater amounts of Fe were accumulated from inorganic supply at the 10 ppm Fe level.     

Urinary tract manifestations of protothecosis in dogs

Records of 13 dogs with systemic infection with Prototheca sp. from 3 veterinary teaching hospitals were reviewed. Acute renal failure secondary to disseminated infection with Prototheca zopfii was diagnosed in 2 dogs. In 1 dog, acute renal failure developed during administration of immunosuppressive drugs for treatment of anterior uveitis. During diagnostic evaluation of this dog, Prototheca sp. organisms were noted in urine sediment and renal biopsy specimens. In the 2nd dog, acute renal failure was diagnosed after treatment for bacterial cystitis. After diagnosis of protothecosis, organisms were successfully isolated by aerobic urine culture. Both dogs with acute renal failure did not respond to conventional medical therapy. In total, Prototheca sp. was noted in urine sediment in 4 of 8 dogs and successfully cultured from urine in 5 of 7 dogs. Four of 5 dogs had organisms noted in the kidneys on histopathologic examination. In all dogs, the species identified was P zopfii. Sensitivity testing of 3 isolates revealed wide differences in in vitro drug resistance. Examination and culture of urine is recommended as a practical method for diagnosis of systemic infection with Prototheca sp.     

乌鲁木齐周围地区绿藻再报

本文再次报道采自新疆乌鲁木齐,南山八一林场,玛纳斯的绿藻４属７种３变种,其中３属４种３变种为新疆新记录 。     

Effect of DHA Containing Oils and Powders on Baking Performance and Quality of White Pan Bread

Different sources of DHA and/or n-3 (omega-3) rich oils, oil emulsions and microencapsulated (ME) powders were tested at two different concentrations with the aim of producing fortified pan bread. Three oils (S-algae, fish and flax), two emulsified algae oils (Emulsion-P and Emulsion-L) and two ME oils (ME-S algae and ME-C algae) were compared. The DHA and n-3 oils replaced part of the shortening in order to obtain 32 g slices enriched with 25 or 50 mg DHA, 35 or 70 mg total n-3 from fish oil and 90 or 180 mg linolenic from flax oil. Addition of oils did not significantly affect water absorption but reduced mix time whereas addition of the ME oils decreased both water absorption and mix time. Breads enriched with flax or ME-C oils had lower volume and higher density than the control, ME-S algae, Emulsion-P and Emulsion-L breads. All breads lost texture throughout 14 d storage, the major changes occurred after 3 d. The ME-S algae oil bread had the best softness after 14 d storage whereas breads produced from ME-S algae or ME-C algae oils had the poorest texture. Sensory evaluations indicated that the color of the ME-S algae oil fortified bread was significantly less preferred than the other loaves. After 6 d the control bread had higher acceptability compared with the rest of the breads enriched with high levels of DHA or omega-3 oils. The high-enriched fish oil bread was well accepted during the first days of storage but had the least preferred acceptability after 13 d. The best fortified breads were those supplemented with S-algae oil, Emulsion-P and Emulsion-L oils.     

Food selection and internal processing in Archegozetes longisetosus (Acari: Oribatida)

The nutritional biology of the oribatid mite Archegozetes longisetosus Aoki was examined using a control (starvation) and four types of food: Protococcus sp. algae from tree bark, two fungi—Stachybothrys sp. and Alternaria sp.—and filter paper. Direct observations, histology, enzymology and plating techniques were employed to record contact with food, contents and structure of the alimentary tract, presence and viability of bacterial microorganisms inside the mite body, and chitinase and cellulase activity of mite homogenates. Algae were highly palatable, resulting in high apocrine secretion and guts that were continuously full. Initially there was no evidence of chitinase or cellulase production. Chitinase activity started after 10 days, probably due to consumption of fungi that invaded the algal cover, and correlated with the presence of chitinolytic bacteria (Serratia rubidea) in the mite homogenate. Alternaria was grazed intensively, but cell walls of spores and hyphae remained intact and no chitinase was detected suggesting that only cell contents were enzymatically digested. Stachybothrys sp. was rejected as food. The bacterium Alcaligenes faecalis was dominant in homogenates in each of the treatments, but under starvation Achromobacter xylosoxidans became co-dominant. Cellulase activity was not detected in any treatment, but strong chitinase activity was induced with a filter paper (colonized by invasive fungi) diet. Furthermore, bacteria were common in mesenchyme between the internal organs in the filter paper and starvation treatments.     

重金属污染土壤毒性的发光菌法与斜生栅藻法诊断

应用斜生栅藻(Scenedesmus obliquus)和明亮发光杆菌T3(Phyotobacterium Phosphoreum)对重金属污染土壤的毒性进行诊断,结果表明,斜生栅藻的增长率和发光菌的相对发光度与土壤中的重金属含量明显相关,并且随重金属投加量的增加,其增长率和发光度逐渐降低,对3种测试参数进行比较,发现采用细胞数增长率作为土壤毒性的检测指标比采用光密度增长率和相对发光度更为敏感。复合污染情况下,由于金属间的协同作用,使土壤的毒性比单一重金属污染时有明显的增强,从而为污染土壤的优先修复提供了理论依据。     

藻类在稻田生态系统中的作用及其对氨挥发损失的影响

本文在总结已有稻田藻类研究结果的基础上,结合温室盆栽试验的初步结果,阐述了藻类对稻田氨挥发损失过程的影响,及其在稻田土壤N素转化、供应与调节中所起的重要作用。提出了减少N素氨挥发损失和合理利用稻田藻类的方法。     

红掌叶片水藻生长条件及其对红掌生长的影响

[目的]研究温室中有利于红掌生长发育及抑制水藻生长的条件。[方法]以红掌的三个品种为试材,定时测定6个温室的温、湿度,观察红掌试验苗的水藻生长情况,计算红掌水藻感染率。[结果]温度为18.3~24.0℃,湿度为70.1%~83.0%,通风不良的环境适合水藻生长;水藻生长与红掌品种有关,在同一温室中,亚利桑娜的水藻感染率要比红色恋人的高;感染水藻的红掌试验苗平均增长高度比没感染水藻的试验苗低1.48 cm、光合速率比没感染的低6.46μmol/(m2.s)。[结论]较低温度、较高湿度和通风不良的条件有利于水藻生长,水藻对红掌生长有负面影响。     

太湖地区贡湖湾生态修复区围隔系统消浪挡藻技术研究

通过在贡湖湾生态修复区与外太湖连接处7#桥外侧设置双层围隔消浪挡藻系统,结合导流门技术,研究该系统的消浪、挡藻和导流效果。结果表明,该系统具有良好的消浪挡藻效果,波浪消减率达到近30%,藻密度下降幅度达到80%以上,导流效果明显。