准好氧生物反应器处理渗滤液系统的驯化研究

将准好氧填埋技术与矿化垃圾技术相结合在实验室内构建了模拟准好氧生物反应器垃圾处理系统,以室内埋龄为3年的矿化垃圾填充准好氧生物反应器,以室内模拟垃圾填埋柱产生的新鲜渗滤液为处理对象,考察了混合培养法、容积负荷渐增法和水力负荷渐增法对反应器内微生物的驯化效果.结果表明,混合培养法较负荷渐增法的驯化效果好,在驯化结束时,采用混合培养法的反应器出水COD为305 mg/L,NH3-N为0.6 mg/L,TN为38.7 mg/L;驯化时间越长则驯化效果越好,同是容积负荷渐增法,经过30 d分阶段驯化和经过20 d分阶段驯化的反应器,其出水COD分别为381 mg/L和1 311 mg/L,NH3-N分别为0.8 mg/L和5.0 mg/L.在准好氧生物反应器处理渗滤液系统的工程应用中,对微生物的驯化可首选混合培养法,同时应保证一定的驯化时间.     

低温驯化速度对鲫鱼离水储藏酶活性的影响

为研究低温驯化及储藏温度对鲫鱼活体离水后储藏的影响,成年鲫鱼(Carassius carassius)放置于水箱中,采用每小时5℃和1℃速率,由25℃匀速降温降至0℃,分别在4℃和0℃冷库中离水储藏24 h,测定鲫鱼新陈代谢及抗氧化相关酶的活力,并探讨低温驯化及离水储藏对鱼体生理状态的影响。结果表明,1℃/h降温有利于乳酸脱氢酶(LDH)活力的保存。经过1℃/h降温驯化后,0℃储藏异柠檬酸脱氢酶活力功能得到了一定保存,脑琥珀酸脱氢酶(SDH)未受影响。丙氨酸氨基转移酶(ALT)活力体现为受储藏温度影响,0℃下其活力得到保存。0℃储藏导致丙二醛(MDA)的积聚,同时低温储藏中血液过氧化氢酶(CAT)集聚而肝脏未表现出明显变化。     

SBR反应器中反硝化除磷菌的快速富集

反硝化除磷菌(DPAOs)能够在缺氧条件下同步完成脱氮除磷,是反硝化除磷工艺的主体。以武汉沙湖污水处理厂二沉池的回流污泥为种泥,采用二段式SBR工艺实现了反硝化除磷菌的快速富集。在第一阶段反应器采用厌氧/好氧(A/O)模式运行,可以实现对除磷菌(PAOs)的快速诱导和富集,运行13 d后,SBR反应器对氮、磷的去除率均达到85%以上。而后进入第二阶段,采用厌氧/好氧/缺氧(A/O/A)模式运行,以快速富集培养反硝化除磷菌,经过26 d的运行,反应器对氨氮和磷酸盐的去除率分别达到92.2%和91.2%左右,且典型周期内硝酸盐的消耗量与磷的吸收量基本呈线性关系,表明系统的反硝化除磷能力得到显著增强。     

脂肪酶产生菌的筛选及其耐甲醇驯化的研究

从土样中分离出34株脂肪酶产生菌,在维多利亚蓝培养基上初筛出透明圈与菌落直径比值较大的6株菌,复筛出产脂肪酶活性较高的菌株FM-1,其所产脂肪酶主要为胞内酶,产脂肪酶活力为132 U/g cell。通过反复的驯化培养方式将菌株FM-1驯化成耐甲醇的优良菌株。在甲醇质量浓度为11 mg/L的培养基中驯化后的脂肪酶相对活力为35%,而出发菌株在此环境中不能生长。     

甜玉米冰温贮藏保鲜研究

研究不同冰温处理对甜玉米贮藏保鲜效果的影响.设计三组实验:直接冰温、装袋+冰温、装袋后低温锻炼+冰温.以含水量、水渍发生率、失重率和总糖为理化指标,并结合感官方法进行综合分析.结果表明:经过5d 4～C低温锻炼后再进行冰温贮藏,19d后甜玉米色香味和口感俱佳,水溃发生率为20%、玉米穗失重率为2.84%、玉米粒含糖量下降12.41%、含水率下降0.34%,分别比对照组降低30%、11.84%、2.15%和1.66%.     

A proteomic approach to cold acclimation of Staphylococcus aureus CECT 976 grown at room and human body temperatures

Staphylococcus aureus is an important pathogenic microorganism that has been associated with serious infection problems in different fields, from food to clinic. In the present study, we have taken into account that the main reservoirs of this microorganism are the human body and some parts of food processing plants, which have normal temperatures of around 37 and 25 °C, respectively. It can be expected that S. aureus must acclimate its metabolism to colder temperatures before growing in food matrices. Since temperature abuse for foods occurs at approximately 12 °C, it is expected that S. aureus must acclimate its metabolism to colder temperatures before growing in food. For this reason, we have performed a proteomic comparison between exponential- and stationary-phase cultures of S. aureus CECT 976 acclimated to 12 °C after growing at 25 °C or 37 °C. The analysis led to the identification of two different protein patterns associated with cold acclimation, denominated pattern A and pattern B. The first was characteristic of cultures at stationary phase of growth, grown at 25 °C and acclimated to 12 °C. The second appeared in the rest of experimental cases. Pattern A was distinguished by the presence of glycolytic proteins, whereas pattern B was differentiated by the presence of general stress and regulatory proteins. Pattern A was related through physiological experiments with a cross-resistance to acid pH, whereas pattern B conferred resistance to nisin. This prompted us to conclude that both molecular strategies could be valid, in vivo, for the process of acclimation of S. aureus to cold temperatures.     

激光预处理种子提高大豆幼苗抗冷害的机理探讨

从能量转移、膜系统和自由基3个方面探讨了激光预处理大豆种子提高其幼苗抗寒性的机理.研究结果表明,激光(He-Ne)预处理大豆种子不但明显地提高大豆种子三磷酸腺苷(ATP)的含量,而且提高其幼苗(子叶期到第一真叶期)的抗低温胁迫的能力.处理组幼苗在3℃～5℃低温胁迫下比对照组有较高的过氧化氢酶(CAT)、过氧化物酶(POD)、超氧化物歧化酶(SOD)和淀粉酶(AML)的活性及可溶性蛋白质含量.同时预处理还降低了幼苗子叶中超氧阴离子(O2-)含量、丙二醛(MDA)的积累量及电解质外渗率.     

高盐度废水生物处理现状与前景展望

简要介绍了国内外高含盐量废水生物处理的研究进展，主要有两段接触氧化、传统活性污泥法、SBR、膜法SBR、UASB、厌氧滤池、A^2/O工艺等，以及各种工艺的运行条件和处理状况。各种工艺在高含盐量条件下，经过适当的驯化培养，其他条件适宜，取得较好的处理效果。并介绍利用在高盐环境下生存的嗜盐细菌技术处理高含盐量废水的发展前景。     

The effects of selected chemicals and water quality on the marine polychaete : Ophryotrocha Diadema

Cultures of a dorvilleid polychaete, Ophryotrocha diadema. have been used here to test the toxicity of a range of pure chemicals, including metals and pesticides. The 48-h LC₅₀ values are reported. In comparison with other marine polychaetes currently used in toxicity tests, O. diadema was found to be equally sensitive to most of the potential pollutants. In an attempt to increase the tolerance of O. diadema to metals. 12 generations were grown during an 18 month period in sea water containing sublethal concentrations of mercury, copper and zinc. This treatment caused an increase in the generation time of the cultures. Acute toxicity tests on the parent. F₅ and F₁₂ generations were not significantly different from each other and it was concluded that there was no measurable increase in tolerance. O. diadema was tested for the bioassay of polluted water by culturing it in water from Belfast Lough, a semi-enclosed marine bay which is used for the disposal of domestic and trade waste. The growth of the parents from 6-segment to adult stage was normal, but egg production was both delayed and reduced in water from the lough when compared to water from a clean source. However, this effect could not be attributed conclusively to anthropogenic contamination.