紫花苜蓿-菌根真菌-根瘤茵对多氯联苯污染土壤的修复作用

以紫花苜蓿为材料,运用盆载试验,通过接种根瘤菌、菌根真菌对多氯联苯污染土壤的修复效应进行了研究。结果表明,紫花苜蓿对土壤中多氯联苯浓度降低具有重要作用,重污染土壤中平均降低了24.48％,轻污染土壤平均降低了19.14％;根瘤菌和菌根真菌双接种强化了紫花苜蓿对多氯联苯的修复作用,污染土壤的修复效果与土壤原污染程度有关;紫花苜蓿-菌根真菌-根瘤菌协同修复效果在重污染土壤中强于轻污染土壤;同时紫花苜蓿对土壤中PCBs表现出较强的耐性,因而可以作为PCBs污染土壤的植物修复材料。     

Biodiversity of the genus Cladophialophora

Cladophialophora is a genus of black yeast-like fungi comprising a number of clinically highly significant species in addition to environmental taxa. The genus has previously been characterized by branched chains of ellipsoidal to fusiform conidia. However, this character was shown to have evolved several times independently in the order Chaetothyriales. On the basis of a multigene phylogeny (nucLSU, nucSSU, RPB1), most of the species of Cladophialophora (including its generic type C. carrionii) belong to a monophyletic group comprising two main clades (carrionii- and bantiana-clades). The genus includes species causing chromoblastomycosis and other skin infections, as well as disseminated and cerebral infections, often in immunocompetent individuals. In the present study, multilocus phylogenetic analyses were combined to a morphological study to characterize phenetically similar Cladophialophora strains. Sequences of the ITS region, partial Translation Elongation Factor 1-α and β-Tubulin genes were analysed for a set of 48 strains. Four novel species were discovered, originating from soft drinks, alkylbenzene-polluted soil, and infected patients. Membership of the both carrionii and bantiana clades might be indicative of potential virulence to humans.Taxonomic novelties: Cladophialophora samoënsis Badali, de Hoog & Padhye, sp. nov., Cladophialophora subtilis Badali & de Hoog, sp. nov., Cladophialophora mycetomatis Badali, de Hoog & Bonifaz, sp. nov., Cladophialophora immunda Badali, Satow, Prenafeta-Boldú, Padhye & de Hoog, sp. nov.     

Well-defined multispecies probiotic and enzyme combination outperforms traditional fermented probiotic applications in an intensive Pacific white shrimp,Litopenaeus vannamei (Boone, 1931), culture system

A series of treatments were designed to evaluate the efficacy of feeding commercial multispecies probiotics feeding with enzymes and fermentation process on the growth parameters and culture environment of Pacific white shrimp, Litopenaeus vannamei (Boone, 1931), in an intensive culture system. Commercial multispecies probiotics and enzymes (PEs) were continuously applied in three different doses, namely (i) 0.2, (ii) 0.4, and (iii) 0.6 mg L⁻¹ and designated as 0.2, 0.4, and 0.6 PE during the first 30 days of intensive culture of Pacific white shrimp, L. vannamei (Boone, 1931). The probiotics were continually applied every alternate day, while the enzymes were added every sixth day throughout the trial period. The PE dose for all treated tanks was increased by 0.2 ppm after 30 days of culture and another 0.2 ppm after day 60. Meanwhile, fermentation technique, which has become the common method applied in Indonesia in the control treatment, was added on the same day with the PE group with increasing dosage, following the same trend with the 0.6 PE group. Results showed that the group receiving 0.6 PE showed higher final biomass, higher mean weight, and protein retention efficiency as well as a lower feed conversion ratio compared with the control treatment. Abundance of Vibrio spp. remained below 10³ cfu mL⁻¹ throughout the trial. Water quality indicators TAN, NO₂ N and NO₃ N peaked in weeks 3–5 and then declined after that until the end of the culture period in all tanks. This decline was significantly faster in PE-treated tanks. Multispecies PEs have potential applications in controlling Vibrio spp., maintaining proper water quality condition, and enhancing the growth of shrimp in intensive culture system.     

不同工业大麻品种对田间5种重金属吸收积累特性的比较

为了分析不同工业大麻品种对不同重金属富集与转移的差异,以云南5个工业大麻主栽品种（ym1~ym5）为试验材料,修复云南矿区重金属污染严重的农田。结果表明： 5个工业大麻品种中,成熟期的根系对Pb和Cd吸收量最大的为ym1,对As、Cu和Zn吸收量最大的为ym3,而ym5对Pb、Cu、Cd和Zn吸收量皆最小;茎叶对As、Cu和Cd吸收量最大的为ym3,对Pb和Zn吸收量最大的分别为ym1和ym2;种子对Pb和Cd吸收量最大的为ym2,对As和Cu吸收量最大的为ym5,对Zn吸收量最大则为ym3,ym1种子对Pb、As和Cu吸收量皆最小,对Cd、Zn吸收最小的品种分别为ym4和ym2;5个品种表现为除Cu外,茎叶富集系数皆大于根,根系向茎叶的转运系数均大于1。研究表明,ym1可作为Pb污染修复植物,ym3可作为As、Zn、Cu和Cd污染修复的适推品种。     

耐镉阿氏芽孢杆菌缓解水稻受镉胁迫的研究

为了探究阿氏芽孢杆菌T61缓解水稻受镉胁迫的效应,运用96孔板法、电感耦合等离子体质谱法、比色法测定菌株T61的镉耐受性、镉去除率和植物促生性;利用绿色荧光蛋白标记的T61,观察菌株在水稻上的定殖;利用蘸根法施加T61菌剂,观察其降低水稻籽粒镉积累的效应。结果表明：菌株T61对Cd²⁺的最大耐受浓度达到500 μmol·L^-1;在含镉液体培养基中培养24 h后,菌株T61对Cd²⁺的去除率超过50%。菌株T61可以合成植物促生性物质吲哚乙酸（6.2 μg·mL^-1）和铁载体（46.6 μmol·L^-1）,并具有溶磷能力（37.1 μg·mL^-1）。菌株T61可以在水稻根和茎上定殖。大田条件下,T61菌剂可以降低营养期水稻茎叶丙二醛含量和抗氧化酶活性,并使水稻728B和NX1B籽粒中的镉含量分别降低13.5%和11.2%。研究表明,阿氏芽孢杆菌T61是一株具有植物促生性的耐镉细菌,可以缓解某些水稻品种遭受的镉胁迫,在镉污染稻田的微生物修复方面具有一定的应用前景。     

反硝化技术对模拟养殖池塘修复的研究

浙江奉化市池塘的底泥经过反复培养、驯化,从中筛选、分离出反硝化细菌,在模拟实验条件下,研究其对不同浓度的硝酸盐氮和亚硝酸盐氮的去除情况,讨论反硝化菌种的生长情况。结果表明,在初始浓度为1、25、50mg·L^-1的硝酸盐氮和亚硝酸盐氮模拟池塘中,随着实验的进行,对污染物的去除效果逐渐提高。其中在1mg·L^-1的浓度组中,3d内硝酸盐氮和亚硝酸盐氮去除率就分别达到了95．8％和90．2％;在25mg·L^-1的浓度组中,第6d硝酸盐氮和亚硝酸盐的去除率分别为93．8％和87．8％;在50mg·L^-1的浓度组中,第6d硝酸盐氮和亚硝酸盐的去除率分别为89．7％和78．7％。此外,反硝化菌对硝酸盐氮的去除效果略优于亚硝酸盐氮,而且硝酸盐氮和亚硝酸盐氮的浓度越低,对其去除效果越好,达到稳定状态的时间越短。在模拟池塘中,菌种的生长情况与硝酸盐氮和亚硝酸盐氮的浓度呈负相关,即污染物的浓度越高反硝化菌的生长情况越差。对反硝化菌的生态影响因子研究表明,其反硝化最适宜的pH值为6～7,温度为25～35℃;而且在同一pH值和温度条件下,硝酸盐氮和亚硝酸盐氮浓度越低,反硝化菌对其去除效果越好。     

石油烃类污染物降解动力学和微生物群落多样性分析

为了探讨不同初始浓度石油污染土壤堆腐化修复机制,以石油降解菌剂和腐熟鸡粪为调理剂,研究了初始浓度分别为5 000(T1)、10 000(T2)和50 000 mg/kg(T3)的石油污染土壤堆腐化修复过程石油烃类污染物降解动力学特征和微生物群落多样性。结果表明:堆腐化修复过程石油烃类污染物降解符合一级反应动力学,反应常数分别为0.012、0.094和0.050 d-1,半衰期分别为6.79、7.37和13.86 d。整个堆腐过程石油烃类污染物平均降解速率分别为112.08、230.05和887.93 mg/(kg·d)。3个处理的孔平均颜色变化率(average well color development)和碳源利用率(除芳香烃类化合物外)随堆腐进程的推进逐渐升高,在堆腐中、后期达到最大,T3处理显著高于T1、T2处理。多聚物类和糖类代谢群是堆腐体系中的优势菌群。主成分分析表明3个处理的微生物群落差异显著(除第9天外),起分异作用的碳源主要是糖类和羧酸类。微生物群落的丰富度指数和均一度指数随堆腐进程的推进逐渐升高并在堆腐后期达到最大,与T1处理相比,T3处理分别高了0.21%和17.64%,差异达到显著水平(P0.05)。微生物群落优势度指数在中期达到最大,T1处理分别比T2、T3处理高2.12%和9.44%,3个处理间差异不显著(P0.05)。堆肥结束时3个处理的种子发芽指数(seed germination index,SGI)分别比堆腐初期提高了18.26%、20.42%和36.41%。该研究结果为黄土高原不同程度石油污染土壤堆腐化修复的应用提供参考依据和理论基础。     

翘鳞香菇研究进展

翘鳞香菇是新近开发的具有市场潜力的食用菌新品种。本文综述了其栽培技术、固体发酵、深层培养、药理活性和生物修复等方面的研究进展,为其进一步开发应用提供参考。     

细菌阿特拉津氯水解酶基因的功能及其应用

简要介绍了能降解除草剂阿特拉津的细菌的种类和它们的生物降解途径、阿特拉津氯水解酶的功能和定向进化的研究进展,以及阿特拉津氯水解酶基因atzA在污染土壤生物修复和转基因植物研究中的应用。     

有机污染土壤生物修复效果的限制因素及提升措施

土壤中的有机污染物主要来源于有机农药、石油污染、工业生产等,其对生态环境和人体健康造成了极大的危害。受有机物污染的土壤能通过物理、化学、生物等一系列的修复技术进行治理,其中生物修复技术被认为是处理有机污染土壤最有效、经济且环境友好的修复技术,但其修复效率受诸多因素影响。本文从气候地理条件、有机污染物的存在形态和土壤自身环境与营养3个方面系统地分析了生物修复技术的限制因素,并从物种选择、生物有效性提升（引入微生物或土壤动物、添加表面活性剂和有机溶剂）及稳定生态系统的构建（添加生物炭、营养补充剂,采用电强化生物修复技术）3个角度科学地提出了提升生物修复技术效率的方法,最后对加强有机物污染土壤复合修复技术的研究进行了展望。