共代谢条件下荧蒽降解菌的差异蛋白质组学分析

以课题组筛选出的多环芳烃高效降解菌--蜡样芽孢杆菌(Bacillus cereus)DQ01菌株为研究对象,以荧蒽为目标污染物,以牛肉膏蛋白胨培养基(LB培养基)为共代谢基质,基于同位素相对和绝对定量技术(iTRAQ)比较细菌在无机盐培养基(MSM培养基)和MSM-LB培养环境中降解荧蒽的全蛋白表达水平,旨在揭示蜡样芽孢杆菌在共代谢过程中分子代谢水平上的变化.结果共检测到64个差异表达蛋白质,其中上调表达的蛋白质有28个,下调表达的蛋白质36个.鉴定到差异蛋白的功能集中在代谢、应激反应、信息传递和调控等方面,同时对比KEGG通路富集分析的结果,也显示细菌有关能量代谢和信息传递、调控的通路产生的变化.比较细菌在是否处于共代谢下的差异蛋白表达,推测细菌在降解多环芳烃过程中的关键环节是小分子代谢和适应外界环境的通路.     

西安市冬季霾污染过程PM2.5上蛋白质的浓度变化与来源分析

利用2019年12月至2020年1月在西安市3次灰霾污染过程中采集的PM_2.5样品,采用BCA试剂法、离子色谱和气相色谱-质谱检测法分别对样品中的蛋白质含量及无机有机化学成分进行了分析测定,结合相关性分析和气团后向轨迹模型分析探讨了PM_2.5上蛋白质对灰霾污染的响应及其在污染过程中可能的作用.结果表明,冬季灰霾污染期间,西安市PM_2.5中蛋白质组分的平均浓度为(5.587±2.421)μg/m³,处于较高水平;蛋白质浓度变化呈现出显著的短期连续变化特征,夜晚略高于白天.蛋白质的浓度与Cl^-和K⁺呈显著的正相关,说明气溶胶中蛋白质的来源与燃煤和生物质燃烧有关;与NO₃^-与SO₄^2-的浓度呈现显著的正相关,表明蛋白质可能参与NO₃^-与SO₄^2-的氧化转化;蛋白质具有良好的吸湿性,在湿度较大时,以其为核心吸附空气中的水蒸气及易溶于水的气态污染物(O₃、SO₂、NO_X以及挥发性有机物等)形成的气溶胶易于发生吸湿增长及非均相反应,可能利于二次气溶胶的生成.     

根瘤菌新类群的全细胞蛋白电泳及16S rDNA全序列分析

应用ＳＤＳ全细胞蛋白电泳技术对根瘤菌３个新类群进行聚类分析,并对３个新类群中心菌株的１６Ｓ ｒＤＮＡ全序列（Ｍｒ≈１．５ｋｂ）进行了测定。将所测序列与ＥＭＢＬ／ＢａｎｋＩＴ／ＤＤＢＪ资料库中根瘤菌及相关菌已知种的１６Ｓ ｒＤＮＡ全序列进行聚类比较,得到系统发育树状图,树状图中,菌株ＳＨ２２６２３和ＳＨ１９３１２与山羊豆根瘤菌、葡萄土壤杆菌、根癌土壤杆菌和悬钩子土壤杆菌在同一个分支上,彼此亲缘关系较     

壬基酚对中国林蛙精巢中StAR表达的影响

为研究水体壬基酚(Nonylphenol,NP)污染对两栖动物精巢中类固醇生成急性调节蛋白(StAR)的影响,将雄性成体中国林蛙(Rana chensinensis)分别暴露于c(NP)为10-7,10-6和10-5 mol/L的水体中10,20和30 d.取其精巢组织,在成功扩增获得273 bp的StAR cDNA片段后合成探针,用原位杂交方法检测StAR mRNA在精巢的表达,用免疫组织化学方法检测StAR蛋白的表达.结果在对照组和各NP处理组中均检测到StAR mRNA和蛋白的阳性表达,阳性反应主要在精巢的Leydig细胞.StAR表达相对值的检测结果表明,c(NP)为10-5 mol/L 的水体对StAR表达有抑制趋势,c(NP)为10-7和10-6 mol/L 的水体可上调StAR的表达,表明NP对StAR表达由抑制转向诱导的临界浓度在c(NP)为10-6 mol/L与10-5 mol/L 之间.在c(NP)为10-7和10-6 mol/L 处理组,StAR表达值随c(NP)的增高而增加.在c(NP)为10-6 mol/L 处理组,暴露30 d后StAR表达相对值最大,呈现NP对StAR表达具有累积效应.c(NP)为10-7 mol/L对StAR表达不随时间延长显示累积效应.提示一定剂量范围的NP可通过调控StAR的表达干扰动物类固醇激素的合成.      

阳离子交换树脂法提取一株除铬(Ⅵ)优势菌(Bacillus sp.)的胞外聚合物

采用阳离子交换树脂法对一株除铬优势菌(Bacillussp.)的胞外聚合物(EPS)进行提取,综合考察树脂量、振摇频率、提取时间三个主要因素对EPS提取效率的影响,确定阳离子交换树脂法提取优势菌Bacillussp.的最佳EPS提取条件.试验结果表明:当菌悬液OD为0.833,树脂量20g,振摇频率120r.min-1,提取时间8h时,EPS的提取效果最佳,提取量高达132.15μg.ml-1菌悬液,而DNA提取量仅1.48μg.ml-1菌悬液.     

三唑酮对离体黄瓜子叶过氧化物酶活性及蛋白质含量的影响

20mg/L三唑酮能显著地抑制离体黄瓜子叶叶绿素a、b、可溶性蛋白质和游离脯氨酸含量及叶绿素a/b的下降,表明三唑酮抑制子叶的衰老。与此同时,三唑酮能不同程度地抑制过氧化物酶（POD）活性升高和H2O2的累积。在黄瓜子叶衰老过程中,叶绿素及蛋白质含量均与POD、H2O2成显著的负相关,表明三唑酮可能通过POD－H2O2酶促系统来抑制叶绿素和可溶性蛋白质的降解。     

Soluble protein and acid phosphatase exuded by ectomycorrhizal fungi and seedlings in response to excessive Cu and Cd

Fungi and their symbionts can alleviate heavy metal stress by exuding soluble proteins and enzymes. This study examined the role of soluble protein and acid phosphatase (APase) exuded by Xerocomus chrysenteron, an ectomycorrhizal fungus, and the seedlings of its symbiont, Chinese pine (Pinus tabulaeformis), under conditions of excessive Cu and Cd. The growth type showed that this poorly studied ectomycorrhizal fungus was capable of tolerating high concentrations of Cu, and may be useful in phytoremediation. X. chrysenteron grew well at 80 mg/L Cu, and the EC50 for Cd was 17.82 mg/L. X. chrysenteron also showed enhanced exudation of soluble protein in both isolated and inoculated cultivations under the influence of Cu and Cd. Soluble protein exudation, however, di ered under Cu and Cd stress in isolates. In mediums containing Cu, soluble protein exudation increased with concentration, but in mediums containing Cd the content of soluble protein increased to a comparable level at all concentrations. This study demonstrated that soluble protein was related to heavy metal tolerance, although the di erent ions played di erent roles. While APase activity in exudates of fungi and seedlings decreased under Cu and Cd stress in comparison to the control, the APase activity in seedlings was maintained by inoculation. Thus, X. chrysenteron facilitated the ability of plant to maintain a normal nutrient uptake, and therefore to protect it from heavy metal toxicity.     

Determination of the carbon content of biomass—A prerequisite to estimate the complete biodegradation of polymers

This article presents a method to determine the carbon content of biomass, which is formed when degrading biodegradable polymers in an aerobic aqueous test system. Existing methods for determining the carbon content of biomass (e.g., fumigazation, protein assays, dry solids) have several disadvantages when applied for polymer degradation tests. In this work a protein assay based on the Lowry method was used. It was shown that the ratio between protein and carbon content is not constant but depends on the composition of the microbial population, the growth phase, and the substrate supply. This effect was used for the method presented in this article. For determining the carbon content of biomass the absorbance obtained by the Lowry test is correlated directly with the carbon content of biomass in dependence on the duration of the degradation test. The calibration curves are obtained by a mixed population of microorganisms during the course of a degradation test.     

Effect of Heavy Metals on the Blood Protein Biochemistry of the Fish CYPRINUS CARPIO AND ITS USE AS A BIO-INDICATOR OF POLLUTION STRESS

Cyprinus carpio were exposed to two non-essential (Hg and Pb)and two essential (Cu and Ni) heavy metal salts at lethal andsub-lethal concentrations. Blood serum total protein, serum globulinand serum albumin was analysed every 2 hr for 24 hrs andagain at 48 and 72 hrs. Serum protein and globulin level showedan intial sharp increase from 2 to 20 hrs, followed by decline thatextend over a period of 72 hrs. Serum albumin showed an initialimmediate decline from 2 to 4 hrs, followed by an intermittent period of recovery and decline that extend over a period of 72hrs. Both lethal and sub-lethal concentrations of metal salts elicited asimilar pattern of response varying only in magnitude. The use offish blood serum protein, albumin and globulin measurements as general indicators of pollutant stress response isdiscussed.