2株石油降解菌生长和降解石油条件的优化

对2株石油降解菌DH-5和DH-9生长的最适培养基成分以及降解石油的最佳环境条件进行了筛选。结果表明,DH-5的最佳培养基成分为ρ(原油)1 g.L-1、ρ(氮源)400 mg.L-1、ρ(磷源)200 mg.L-1、ρ(酵母浸出液)20 mg.L-1,最有效利用的氨基酸为精氨酸,最适环境条件为pH 7.0、盐度20、温度15～30℃;DH-9的最佳培养基成分为ρ(原油)1 g.L-1、ρ(氮源)400 mg.L-1、ρ(磷源)100 mg.L-1、ρ(酵母浸出液)20 mg.L-1,最有效利用的氨基酸为天冬氨酸,最适环境条件为pH 7.5、盐度20、温度30℃。当ρ(原油)为20 g.L-1时,DH-9的生物量和原油降解率分别是DH-5的2.58倍和2.29倍。研究表明,DH-9对高浓度原油的耐受性明显强于DH-5,而DH-5对低温的适应性优于DH-9,2个菌株对高盐度的适应性均较强。     

实时荧光定量PCR技术对氨氧化细菌的研究

传统的PCR技术只能实现对核酸的定性检测而无法对其进行定量研究。随着分子生物学技术的发展,在传统PCR技术的基础上发展起来的实时荧光定量PCR技术实现了对核酸的定量研究。该技术是向常规PCR反应体系中加入荧光染料或荧光探针,通过监测PCR反应过程中荧光信号的变化来实现对核酸的定量。实时荧光定量PCR技术具有应用范围广、灵敏度高、操作简单、工作量低等特点,在医学和微生物学领域已广泛地应用于疾病诊断、病毒定量检测、微生物群落结构分析及演替规律的研究。文章综述了该项技术的原理、特点及其在环境氨氧化细菌研究中的应用,同时也指出了该技术存在的问题及其发展应用前景。     

无色硫细菌处理含硫废水的试验研究

在升流式填料塔中,通过污泥训化产生大量的硫杆菌,从而形成稳定生物膜.采用循环单因素实验研究和分析硫化物容积负荷与溶解氧(DO)共同作用下硫化物(S2-)的去除规律、硫酸盐的生成规律以及单质硫的生成率,并对建立的模拟方程进行验证.结果表明,DO是影响反应器顺利启动和稳定运行的主要因素;同时pH值对处理效果的影响也比较大;高浓度S2-有利于其本身的去除;有机物负荷对生物除硫效果影响不大;在水力停留时间(HRT)大于30min时,除硫效果基本没有很大变化.     

Simultaneous removal of COD and nitrogen using a novel carbon-membrane aerated biofilm reactor

A membrane aerated biofilm reactor is a promising technology for wastewater treatment. In this study, a carbon-membrane aerated biofilm reactor （CMABR） has been developed, to remove carbon organics and nitrogen simultaneously from one reactor. The results showed that CMABR has a high chemical oxygen demand （COD） and nitrogen removal efficiency, as it is operated with a hydraulic retention time （HRT） of 20 h, and it also showed a perfect performance, even if the HRT was shortened to 12 h. In this period, the removal efficiencies of COD, ammonia nitrogen （NH4^＋-N）, and total nitrogen （TN） reached 86%, 94%, and 84%, respectively. However, the removal efficiencies of NH4^＋-N and TN declined rapidly as the HRT was shortened to 8 h. This is because of the excessive growth of biomass on the nonwoven fiber and very high organic loading rate. The fluorescence in situ hybridization （FISH） analysis indicated that the ammonia oxidizing bacteria （AOB） were mainly distributed in the inner layer of the biofilm. The coexistence of AOB and eubacteria in one biofilm can enhance the simultaneous removal of COD and nitrogen.     

Inactivated properties of activated carbon-supported TiO2 nanoparticles for bacteria and kinetic study

The activated carbon-supported TiO2 nanoparticles(TiO2/AC)were prepared by a properly controlled sol-gel method.The effects of activated carbons(AC)support on inactivated properties of TiO2 nanoparticles were evaluated by photocatalytic inactivation experiments of Escherichia coli.The key factors affecting the inactivation effciency were investigated,including electric power of lamp, temperature,and pH values.The results show that the TiO2/AC composites have high inactivation properties of E.coli in compari...     

Inactivated properties of activated carbon-supported TiO2 nanoparticles for bacteria and kinetic study

The activated carbon-supported TiO₂ nanoparticles (TiO₂/AC) were prepared by a properly controlled sol-gel method. The effects of activated carbons (AC) support on inactivated properties of TiO₂ nanoparticles were evaluated by photocatalytic inactivation experiments of Escherichia coli. The key factors affecting the inactivation efficiency were investigated, including electric power of lamp, temperature, and pH values. The results show that the TiO₂/AC composites have high inactivation properties of E. coli in comparison with pure TiO₂ powder. The kinetics of photocatalytic inactivation of E. coli was found to follow a pseudo-first order rate law for TiO₂/AC composites, and kinetic behavior could be described in terms of a modified Langmuir-Hinshelwood model. The values of the adsorption equilibrium constants for the bacteria, K_c, and for the rate constants, k_r, were certainly depended on TiO₂ content. At 47 wt.% TiO₂ coatings with the highest rate constant, the K_c and k_r were 1.17 × 10⁻⁸L/cfu and 1.43 × 10⁶ cfu/(L·min), respectively. The variety of parameters shows significant effects on inactivation rate. The outer layer of bacteria decomposed first resulting in inactivation of cell, and with further illumination, the cells nearly decomposed.     

Decomposition and phosphorus release from four different size fractions of Microcystis spp. taken from Lake Taihu, China

Decomposition of Microcystis is accompanied by the release of phosphorus,during bacteria play an important role.A series of experiments were undertaken to evaluate the effect of bacteria on the decomposition of Microcystis taken from Lake Taihu,China,a lake that is suffering from dense Microcystis blooms.The 16 experiments involved four size fractions of colonial Microcystis with or without the addition of lake sediment and Gram-negative bacterial inhibitor NAN_3.The highest decomposition rates were reco...     

采油污水的电催化杀菌工艺及其作用机理

利用形稳阳极借助于电催化方法对油田污水中的硫酸盐还原菌(SRB)、铁细菌(FB)、腐生菌(TGB)进行杀菌实验研究,确定了最佳操作条件,并对杀菌机理作了初步探讨。结果表明,在电流密度30mA/cm2、极板间距2cm、pH值5.0下处理30min时三种细菌的杀菌率均达100%。通过对杀菌机理的初步探讨表明,在电催化过程中产生的活性氯对杀菌效果起主要作用。     

生物净化槽中脱氮菌种的筛选鉴定与条件优化

从生物净化器／强化浮床组合工艺处理农村生活污水工程的生物净化器中提取菌种。在以乙酸钠为碳源的专性脱氮培养基上分离筛选出厌氧反硝化菌株A-5,运用生物量和脱氮率的实验测试其最适生长条件为：30℃、pH值为7．7、最适接种量为20％。在最适条件下的降解能力为：培养液初始NO3-N浓度为100mg·L^-1,24h内脱氮率达90．1％。通过形态学和生理特性观察经过菌种鉴定测定A-5为门多萨假单胞菌属（Pseudomonas Medoeina）。该菌株脱氮效果明显,可广泛用于农村生活污水的处理。     

两种N源对石油烃降解菌群降解柴油能力的影响

分别以酵母膏作为有机N源,(NH4)2SO4作为无机N源,在含N量相同(70 mmol/L)的条件下,按接种量2%,柴油1%,25℃,150 r/min摇床恒温培养,对海洋石油烃降解菌群进行了为期30 d 的液体摇瓶降解实验,通过GC-MS测定和分析,对柴油中正烷烃的降解情况进行了对比研究.结果表明,对柴油含量为1%的培养液,应用这两种不同N源,降解菌群对正烷烃的最终降解效果相同,均能完全降解,但有机N源只需3 d 时间就能完全降解正烷烃,比无机N源的降解时间短10倍多.因此,酵母膏对柴油的微生物降解具有极大的促进作用.