石油烃降解菌的筛选及其生长条件研究

实验从锦州石化长期被高浓度的烃类化合物污染的土壤中采取土样,经反复富集培养后分离得到降解原油的单一菌株X2,并对菌株X2生长条件进行了优化,其优化后的最佳生长条件为:温度30℃,pH值为7,恒温摇床转速为190 r/min,盐度为2.5%。同时,实验利用最佳条件下培养获得的对数生长期降解菌X2降解处理含原油1.0%的无机培养液,经过24 h处理,测得降解菌X2对原油的降解能力达到60.6%。     

洋河水库微囊藻毒素及产毒株种群丰度的时空分布特征

在洋河水库设置6个采样点,于2015年5—10月采集水样,利用高效液相色谱测定了微囊藻毒素(MC-LR、MC-RR、MC-YR)的浓度,并采用基于mcy A和mcy B基因的荧光定量PCR技术检测产毒蓝藻与产毒微囊藻种群.同时,分析了水体中微囊藻毒素浓度和组成的时空分布特征,以及产毒蓝藻与产毒微囊藻丰度的动态变化.结果表明,洋河水库微囊藻毒素(Microcystins,MCs)浓度范围为0.24~10.99μg·L~(-1);水体中产毒蓝藻占总蓝藻种群丰度的7%~55%,产毒微囊藻占总微囊藻种群丰度的8%~59%,是主要的产毒蓝藻;微囊藻毒素浓度与产毒株种群丰度时空分布特征一致,季节变化规律为夏季秋季春季,空间分布表现为西洋河口附近区域高于东洋河口附近区域;而微囊藻毒素组成无显著时空差异,均以MC-RR和MC-LR 2种亚型为主.Pearson相关分析显示,产毒微囊藻种群丰度及其比例是影响微囊藻毒素浓度变化的主要因素,且其与总磷和叶绿素a浓度呈显著正相关(p0.01).     

异养硝化-好氧反硝化菌协同竞争对脱氮特性的影响

为了探讨在脱氮过程中异养硝化-好氧反硝化菌类之间的协同和竞争作用,以A2/O工艺好氧污泥中筛出的三株异养硝化-好氧反硝化菌——XH02、XH03和FX03为研究对象,经16S rDNA基因序列系统发育分析,鉴定XH02为人苍白杆菌(Ochrobactrum sp.),XH03和FX03为假单胞菌(Pseudomonas sp.).在此基础上,分别考察了单菌株和复合菌株(XH02+XH03、XH02+FX03、XH03+FX03和XH02+XH03+FX03) 在异养硝化和好氧反硝化条件下的脱氮特性.结果表明:菌株XH02和XH03具有高效脱氮特性,在异养硝化过程中,第24小时对NH₄+-N的去除率分别为90.2%和89.5%;在好氧反硝化过程中,二者在第24小时对NO₃--N的去除率分别为91.8%和94.0%.复合菌株XH02+XH03无论在异养硝化还是好氧反硝化过程中,均能相互协同,促进生长,进一步提高了脱氮效率,在第24小时对NH₄+-N和NO₃--N的去除率分别达到97.1%和96.7%.在硝化和反硝化过程中,菌株FX03对XH02、XH03均存在着竞争关系,FX03的存在会抑制菌株XH02和XH03的生长,显著降低脱氮效率.研究显示,异养硝化-好氧反硝化菌XH02和XH03之间的协同作用可以强化废水生物处理,提高脱氮效率.      

高温纤维素降解菌群筛选及产酶特性

从园林废弃物鸡粪混合堆肥的高温期堆肥样品中,筛选出6株具有高效纤维素降解性的高温菌.通过16S rRNA基因序列比对和构建系统发育树分析,初步鉴定这6种菌株为高温紫链霉菌(Streptomyces thermoviolaceus)、嗜热淀粉酶链霉菌(S.thermodiastaticus)、嗜热一氧化碳链霉菌(S.thermocarboxydus)、黄白链霉菌(S.albidoflavus)、热普通链霉菌(S.thermovulgaris)和波茨坦短芽孢杆菌(Brevibacillus borstelensis).目前为止,国内外对纤维素降菌群的研究较少,本研究将6种菌株1∶1等体积混合制成混合菌群M-1,利用DNS法比较混合菌群M-1和单一菌株的产羧甲基纤维素酶(CMCase)能力.结果表明,混合菌群M-1比单一菌株产CMCase能力强.对混合菌群M-1产CMCase活力特性进行研究,确定混合菌群M-1的最佳产酶条件.结果表明,混合菌群M-1以体积分数1%接种量接种于初始p H为4的以麸皮+淀粉混合物为碳源,玉米粉为有机氮源,KNO_3为无机氮源的培养基中,45℃条件下培养,能够有最大的酶活,达135.9 U·m L~(-1).条件优化后,产酶能力提高1.8倍.     

Prioritizing occupational injury prevention in the construction industry: injury severity or absence?

PROBLEM: National occupational injury prevention goals often prioritize the reduction of serious injuries. This study analyzed whether this prioritization is credible in respect to lost-time injuries and short and long term work absence, and the implications this has for injury severity-based versus injury absence-based prevention approaches. METHOD: The data consisted of national and work-site specific injury and absence data from construction workers in Denmark, including workers from the Copenhagen Metro construction sites, during the period 2000-2001. RESULTS AND IMPACT ON INDUSTRY AND GOVERNMENT: Absence length was significantly dependent on the type of injury. Sprains and strains were most prevalent and accounted for approximately one third of injuries and absence. Fractures accounted for one sixth of injuries and the greatest proportion of long-term absence. The results give credibility to the need for targeting sprains and strains in injury and absence prevention initiatives.     

餐厨垃圾好氧生物处理菌株的选育

文章以枯草芽孢杆菌、巨大芽孢杆菌等10株细菌为出发菌株,以耐高温、生长速度快、生物安全性、生物拮抗性以及产酶能力为筛选原则,从中筛选得到4株细菌,分别为:地衣芽孢杆菌(Bacillus licheniformis,TKFW1003)、巨大芽孢杆菌(Bacillus megaterium,TKFW1005)、纳豆芽孢杆菌(Bacillus natto,TKFW1102)、枯草芽孢杆菌(Bacillus subtilis,TKFW1108)。然后将筛选得到的4株细菌按10%的比例添加到30 L固态发酵罐中,再添加10%的麸皮和50%的水为辅料,对餐厨垃圾进行固态发酵处理。最后将固态发酵结束后得到的产品取出烘干粉碎,经检测:经好氧微生物处理后得到的产品,其有效活菌数、有机质含量、水分含量及蛔虫卵死亡率等指标均达到了农业部农用有机肥标准,此法实现了餐厨垃圾的无害化、资源化、减量化处理,具有生产成本低、无二次污染、可操作性强等优点。     

优良菌对焦化废水的降解性能研究

以CODCr为控制指标 ,利用分离筛选出的八株优良菌及其与活性污泥的混合体对焦化废水的降解特性进行了研究。结果表明 ,单一优良菌对焦化废水CODCr的去除效果不如活性污泥好 ;混合优良菌株的降解效果比单一菌株好 ,不同优良菌株混合时 ,CODCr的去除率各不相同。相同条件下 ,活性污泥对照组CODCr去除率仅为 5 2 2 % ;优良菌与活性污泥混合使用时 ,CODCr去除效果比单独使用优良菌或活性污泥均有明显提高     

So far,so good: Up to now,the challenge–hindrance framework describes a practical and accurate distinction

There are many ways to categorize work‐related stressors, and in recent years, a common distinction in occupational health psychology is between stressors viewed as challenges versus hindrances. Is this a useful conceptualization that provides practical and theoretical implications for IO psychologists? As Kurt Lewin famously prescribed, “there is nothing so practical as a good theory,” and we discuss the challenge–hindrance framework as a developing theory that can be useful for researchers and practitioners. We note that some of the early thinking and development of the challenge–hindrance distinction relied on both resource and appraisal theories of stress. Overall, we find that the challenge–hindrance distinction can be viewed as a framework that is useful by producing interesting, valuable, and innovative research. Simply striving to find meaningful and useful categorizations of stressors can lead us to discover new insights into the occupational stress domain, and the challenge–hindrance categories have already spurred a great deal of research.     

RESPONSES OF HETEROTHROPHIC BACTERIAL POPULATIONS TO pH CHANGES IN COAL ASH EFFLUENT1

ABSTRACT: Total culturable heterotrophic bacteria in a coal ash basin and drainage system were monitored over a period of two years. In the first year heavy (bottom) ash was sluiced to the basin resulting in a pH of 6.5. During the second year fly ash was precipitated and added to the sluice lowering the basin pH to 4.6. Sulfate concentrations during 1975 ranged from 16–73 ppm (mean 33) and in 1976 from 44–88 ppm (mean 72). Mean annual basin temperatures were 28.8 and 26.0 C, respectively. Approximately 1500 m in the receiving swamp below the basin, mean pH and temperature were 6.8 and 22.2 C for the first year, and 5.4 and 22.1 C for the second. Total culturable bacteria and diversity (colony types) were reduced at all sampling stations by 44 and 30 percent, respectively, whereas the percentage of the population comprised of chromagenic bacteria increased by 51 percent at the lower pH; Data indicated the pH had a greater effect than did water temperature when temperature was within the range of 15–25 C. The predominant genera within the system in the first year were Bacillus, Sarcina, Achromobacter, Flavobacterium, and Pseudomonas. In the second year, at the lower pH, predominant genera were Pseudomonas, Flavobacterium, Chromobacterium, Bacillus, and Brevibacterium.     

高絮凝性微生物育种生物技术研究与应用进展

本文从微生物絮凝性遗传学，絮凝基因分子克隆，絮凝菌种资源开发，微生物絮凝剂的研制与絮凝剂的研制与絮凝污染物的优势等方面进行了综述报导，同时对絮凝性微生物产生絮凝性的有关机理和条牛进行了讨论。