氮源对克雷伯氏菌NIII2分泌絮凝剂特性的影响

实验研究了蔗糖为碳源,硝酸钠、脲、蛋白胨、硫酸铵和氯化铵等氮源对NIII2发酵产絮凝剂的影响。结果表明,发酵液起始pH值为7.50,以硝酸钠为氮源,发酵液pH会上升,升至7.60～8.34时,NⅢ2菌株开始大量分泌微生物絮凝剂,发酵72 h,产量可达7.5 g/L,该产量是目前报道的克雷伯氏菌产絮凝剂的最高值。脲为氮源,pH则下降,降至5.04～6.49时,大量分泌絮凝剂,发酵72 h产量达5.2 g/L。蛋白胨、氯化铵和硫酸铵等为氮源时,pH下降十分明显,pH小于3.71时有絮凝剂分泌,发酵72 h产量约2.0 g/L或更小。以硝酸钠和脲为氮源时,发酵液中有黄色物质分泌,该黄色物质出现或黄色逐渐加深,是NIII2菌高产絮凝剂的标志。除硫酸铵外,其他氮源发酵所产絮凝剂为O-糖蛋白。当以硝酸钠、脲、蛋白胨、硫酸铵和氯化铵为氮源时,絮凝剂中蛋白的含量分别为9.55%、33.28%、19.39%、13.81%和15.51%,且蛋白含量越高,絮凝剂活性越大。     

Profenofos induced modulation in physiological indices,genomic template stability and protein banding patterns of Anabaena sp. PCC 7120

To understand the mechanism underlying organophosphate pesticide toxicity, cyanobacterium Anabaena PCC 7120 was subjected to varied concentrations (0, 5, 10, 20 and 30 mg L^?1) of profenofos and the effects were investigated in terms of changes in cellular physiology, genomic template stability and protein expression pattern. The supplementation of profenofos reduced the growth, total pigment content and photosynthetic efficiency of the test organism in a dose dependent manner with maximum toxic effect at 30 mg L^?1. The high fluorescence intensity of 2′, 7′ –dichlorofluorescin diacetate and increased production of malondialdehyde confirmed the prevalence of acute oxidative stress condition inside the cells of the cyanobacterium. Rapid amplified polymorphic DNA (RAPD) fingerprinting and SDS-PAGE analyses showed a significant alteration in the banding patterns of DNA and proteins respectively. A marked increase in superoxide dismutase, catalase, peroxidase activity and a concomitant reduction in glutathione content indicated their possible role in supporting the growth of Anabaena 7120 up to 20 mg L^?1. These findings suggest that the uncontrolled use of profenofos in the agricultural fields may not only lead to the destruction of the cyanobacterial population, but it would also disturb the nutrient dynamics and energy flow.     

利用微藻同步实现CO2生物固定与养殖废水脱氮除磷

文章欲通过对小球藻Chlorella sp.的优化培养提高微藻的固碳率以及对养殖废水中氮、磷的去除率。探讨了光强、初始氮浓度(ITNC)、CO2通气比、通气间隔时间和连续培养时间等因素对Chlorella sp.固定CO2和净化污水的能力的影响。结果表明,在光强240μmol/(m·s)、初始氮浓度128 mg/L、通气比0.3 m3/(m3·min)、通气通断间隔15 s/60 s条件下培养10 d,微藻达到最高固碳率564.67 mg/(L·d),与此同时,氮、磷去除率和生物质浓度分别达到66.72%、55.95%和3.50 g/L。     

春季角毛藻对N/P值响应的FRD判别

首次运用FRD判别法,探讨了角毛藻(Chaetocerossp.)生长对N/P值的响应过程。通过大亚湾春季现场观测的角毛藻细胞数量与DIN/PO4比值关系分析,构建关系曲线的完全样本进行泛函回归分割(FRD)判别。FRD判别表明,角毛藻是以3种不同的生长状况响应N/P值变化,即在N/P<15.79(±1.41)时,角毛藻数量随N/P值增大处于缓慢生长状况;在N/P=15.79(±1.41)～59.90(±4.28)之间时,角毛藻数量则随N/P值增大而迅速增长;而当N/P>59.90(±4 28)时,角毛藻数量达到最大生长值,并处于上下涨落状态。     

Endocrine disrupting effects on Chinese rare minnow (Gobiocypris rarus) fed with field collected Limnodrilus sp

The potential endocrine disrupting effects and other toxicity effects on aquatic biota resulted from food uptake was simulated by feeding the laboratory cultured rare minnow ( Gobiocypns rams) with field collected Limnodnlus sp. The results indicated that the food chain processes affected significantly the growth, slightly reduced gonadosomatic indices, and elevated hepatosomatic indices. There was an obvious vitellogenin(VTG) induction, which generally only occurred in mature female, in the serum of juvenile rare minnow and mature male when fed with Limnodrilus sp. In addition, the rare minnow feeding on Limnodnlus sp. had significantly high renal indices, it meant obvious renal hyperplasia. The present work suggested that Limnodnlus sp. from field water may contain toxic pollutants and could lead to endocrine disruption effects to the predators. It was concluded that endocrine disruptors may not only be assimilated through water, but also be bioconcentrated through food web. The results also suggested the importance of food selection in conducting the study of endocrine disruption effects using sensitive species.     

1株低温石油烃降解菌的分类鉴定及降解特性研究

从渤海油船泄漏区域的海底泥中筛选到1株能降解柴油的低温石油烃降解菌T7-2,初步鉴定为红平红球菌(Rhodococcus erythropolis).研究表明,利用工业乙醇无机盐培养基培养液体种子是适宜的,其最适温度和pH分别为15℃和7.8,工业乙醇最适加入量为0.5％,菌体浓度为10⁸ CFU/mL.接种人工海水烃降解培养基后,通过补加氮源 (NH₄)₂SO₄ 2.64　g/L、磷源Na₂HPO₄ 2.5 g/L和酵母粉 0.015 g/L后,15℃振荡培养7　d,降解率可以达到73.2％.该菌降解烷烃的范围很广泛,C12～C36均有不同程度的降解.     

4株正十六烷降解菌的降解能力及代谢动力学特性

从处理采油废水的活性污泥中分离出4株产生物表面活性剂的正十六烷高效降解菌。菌株A14和B45为非脱羧勒克菌（Leclercia adecarboxylata）,菌株C28和A27为肠杆菌（Enterobacter sp.）。在NaCl质量浓度15~25 g/L、pH 6.0~7.0、接种量10%（φ）,培养温度37 ℃,摇床转速160 r/min、正十六烷体积分数0.30%的条件下降解16 d后,菌株A14、B45、C28和A27的正十六烷降解率分别为93.7%,87.8%,73.3%,65.7%。4株菌所产生的生物表面活性剂均为磷脂类表面活性剂。菌体生长满足逻辑斯蒂模型,正十六烷的降解满足一级反应动力学模型。菌株C28、A27的生长速率快于菌株A14、B45,菌株A14、B45的正十六烷降解速率快于菌株C28、A27。     

Simultaneous biodegradation of bifenthrin and chlorpyrifos by Pseudomonas sp. CB2

The degradation of bifenthrin (BF) and chlorpyrifos (CP), either together or individually, by a bacterial strain (CB2) isolated from activated sludge was investigated. Strain CB2 was identified as belonging to genus Pseudomonas based on the morphological, physiological, and biochemical characteristics and a homological analysis of the 16S rDNA sequence. Strain CB2 has the potential to degrade BF and CP, either individually or in a mixture. The optimum conditions for mixture degradation were as follows: OD_600nm = 0.5; incubation temperature = 30°C; pH = 7.0; BF-CP mixture (10 mg L^?1 of each). Under these optimal conditions, the degradation rate constants (and half-lives) were 0.4308 d^?1 (1.61 d) and 0.3377 d^?1 (2.05 d) for individual BF and CP samples, respectively, and 0.3463 d^?1 (2.00 d) and 0.2931 d^?1 (2.36 d) for the BF-CP mixture. Major metabolites of BF and CP were 2-methyl-3-biphenylyl methanol and 3,5,6-trichloro-2-pyridinol, respectively. No metabolite bioaccumulation was observed. The ability of CB2 to efficiently degrade BF and CP, particularly in a mixture, may be useful in bioremediation efforts.     

土壤分离菌株去除水溶液中铅离子研究

金属及微生物种类、pH和接触时间是决定生物吸附效果的关键因素.从受铅污染的土壤中分离出5株有生物吸附铅离子能力的菌株,并鉴定吸附能力最强的菌株1为芽孢杆菌;试验了pH、接触时间和初始铅离子浓度对该芽孢杆菌生物吸附铅的影响,在温度为25℃时,pH值3.0、初始铅离子浓度250 mg/L、吸附时间不超过15 min有最大吸附量92.27 mg/g,此时去除率为73.82%,且25℃吸附平衡基本符合Langmuir等温模型.因此,用该芽孢杆菌生物吸附去除水溶液中铅是可行的.     

耐酸性异养菌的分离及其在制革污泥重金属生物淋滤中的作用

从制革污泥中分离出一株异养微生物,经鉴定属于红酵母菌属(Rhodotorula sp.)R30, 测定菌株R30的适宜生长pH范围为3～7,但能耐受pH 2.5至1.5的酸性环境,最适生长温度28℃.酵母R30在污泥水溶性有机物(DOM)中培养96h,水溶性有机碳(DOC)从1485mg/L降至345mg/L,菌数达4.8×10⁷mL^-1.将污泥预酸化至pH 6.5,在进行污泥的生物淋滤过程中,添加酵母处理与不添加酵母处理的对照相比,淋滤时间减少了4d,淋滤周期显著缩短,在7d的淋滤时间内,重金属Cr的溶出率提高39%.