外生菌根真菌Xerocomus chrysenteron对DDT胁迫的耐受性及酶响应研究

在纯培养条件下,研究了外生菌根真菌红绒盖牛肝菌(Xerocomus chrysenteron)对不同浓度DDT的生长效应、耐受性和氧化酶活性,测定了在DDT浓度为80.0 mg·L^-1液体培养条件下菌种生物量积累和漆酶活性随培养时间的变化. 结果表明,不同浓度DDT处理并不会改变被试菌种的生长模式,所有处理组均为典型的Logistic增长;Xerocomus chrysenteron对DDT胁迫有很好的耐受性,其半抑制浓度可达139.75 mg·L^-1;在80.0 mg·L^-1液体培养条件下,Xerocomus chrysenteron生长正常,且36 d后培养液中DDT残留率仅为初始添加量的3.5%;在高浓度DDT胁迫下,被试菌种的漆酶和过氧化物酶活性显著增强,但液体培养条件下漆酶从第16 d开始出现,36 d后培养液中漆酶活性和比活力分别达到107.24 U·L^-1和61.77 U·g-1.外生菌根真菌Xerocomus chrysenteron通过不同方式来响应DDT胁迫,显示出生物降解甚至矿化DDT的巨大潜力.     

漆酶催化酚类、苯胺类化合物的动力学分析及其测定废水中邻苯二酚的应用研究

含酚、苯胺类废水是环境中水污染的重要来源之一.本研究以漆酶分析酚类及苯胺类底物的动力学特性为基础,建立酚类、苯胺类化合物的分析方法.以分光光度法测定漆酶催化0～10mg/L酚类及苯胺类底物的反应速率,作出底物浓度与反应速率的标准曲线,采用漆酶筛查并检测了3种焦化废水中非挥发酚类含量.结果表明,漆酶的酚类及苯胺类底物主要以多元酚、氨基酚及多元胺为主,其中酚类的最适pH在7.0左右,苯胺类在4.5～5.0之间,各底物Km值大小在0.4～10mmol/L之间.除联苯胺外,分光光度法所得到的标准曲线均具有较好的一级反应动力学线性关系,相关系数R2在0.96以上.3种焦化废水中邻苯二酚含量分别为190.5、265.8和155.3mg/L,回收率介于91.9%～115.8%之间.     

制革废水和印染废水的综合毒性评估及鉴别

研究采用成组生物毒性试验(发光菌急性毒性、斑马鱼幼鱼急性毒性,斑马鱼胚胎发育毒性和小球藻急性毒性),结合理化指标,通过毒性单位、平均毒性(average toxicity,Av Tx)、毒性指数(toxic print,Tx Pr)、最敏感的测试(most sensitive test,MST)和潜在毒性效应指数(potential ecotoxic effects probe,PEEP)对不同工艺阶段印染及制革废水进行毒性削减评估.结果表明PEEP能兼顾废水排放量与毒性效应,更为客观地表征了废水综合毒性,PEEP评价结果显示制革废水和印染废水的毒性削减率分别达到36.8%和23.2%.最后,以发光菌作为受试生物,采用毒性鉴别评估(toxicity identification evaluation,TIE)技术,对印染废水进行毒性鉴别.结果表明,印染废水中主要的致毒物质为非极性有机污染,其次为可滤性化合物,然后是重金属、氧化性物质以及挥发性物质.     

简青霉Penicillium simplicissimum木质素降解能力

从土壤中分离得到一株真菌经鉴定为简青霉Penicillium simplicissimum,将该菌用于木质素类化合物利用、染料脱色、天然木素降解及产酶特性等研究,充分证实该菌具有木质素降解能力.简青霉降解木质素是木质素过氧化物酶(LiP)、漆酶(Lac)和木聚糖酶共同作用的结果,降解主要发生在LiP与木聚糖酶活高产的初级代谢阶段,与白腐真菌表现出不同的作用机制.25d培养可使稻草木质素绝对量损失0.23g,降解率达14.94%,同时纤维素、半纤维素也有较高程度的降解.而pH值、Cu²⁺和Mn²⁺浓度对木质素的降解有较大影响.     

化工生化尾水中溶解性有机污染物的富集分离

采用液液萃取法和树脂吸附法对化工园区的生化尾水中溶解性有机污染物进行富集、分离,通过气相色谱-质谱分析表明化工生化尾水中普遍含有四氯乙烯、苯类和烷烃类有机毒物,而不同来源的化工生化尾水中疏水性、亲水性和中性有机质的含量相差较大,分子量分布也不相同,液相色谱-质谱分析表明树脂富集分离后,氨基酸、邻苯二甲酸酯和糖类物质成为尾水中主要有机物。     

耐高浓度沼液产油小球藻的分离鉴定与特征分析

本研究从长期在空气中放置的沼液中分离得到1株可以耐受高浓度沼液的藻株,经形态和分子生物学方法鉴定为小球藻属的一种,命名为Chlorella sp.BWY-1.本研究所用的沼液来自于以固液分离后的猪场废水为发酵原料的沼气工程.与普通小球藻Chlorella regularis(FACHB-729)的对比研究表明,Chlorella sp.BWY-1在BG11和不同浓度的沼液中都有相对较强的生长速率、生物量积累能力和氮磷等污染物去除能力.Chlorella sp.BWY-1在BG11中有最高的生长速率和生物量生产力(324.40 mg·L-1,以dw计),但是其含油量和油脂生产力随着沼液浓度的增加而增加.在未稀释的沼液中Chlorella sp.BWY-1的含油量可达44.43%,油脂生产力达108.70 mg·L-1.分析结果表明该藻株在养殖废水处理和生物能源方面具有一定的应用潜力,可以结合固液分离、厌氧发酵等其他技术用于养殖场废水的处理和生物柴油的制取.     

Enhanced oxidation of benzo[a]pyrene by crude enzyme extracts produced during interspecific fungal interaction of Trametes versicolor and Phanerochaete chrysosporium

The effects of interspecific fungal interactions between Trametes versicolor and Phanerochaete chrysosporium on laccase activity and enzymatic oxidation of polycyclic aromatic hydrocarbons (PAHs) were investigated. A deadlock between the two mycelia rather than replacement of one fungus by another was observed on an agar medium. The laccase activity in crude enzyme extracts from interaction zones reached a maximum after a 5-day incubation, which was significantly higher than that from regions of T. versicolor or P. chrysosporium alone. The enhanced induction of laccase activity lasted longer in half nutrition than in normal nutrition. A higher potential to oxidize benzo[a]pyrene by a crude enzyme preparation extracted from the interaction zones was demonstrated. After a 48 hr incubation period, the oxidation of benzo[a]pyrene by crude enzyme extracts from interaction zones reached 26.2%, while only 9.5% of benzo[a]pyrene was oxidized by crude extracts from T. versicolor. The oxidation was promoted by the co-oxidant 2,2'-azinobis-3-ethylbenzthiazoline-6-sulphonate diammonium salt (ABTS). These findings indicate that the application of co-culturing of white-rot fungi in bioremediation is a potential ameliorating technique for the restoration of PAH-contaminated soil.     

Characterization of a salt-tolerant bacterium Bacillus sp. from a membrane bioreactor for saline wastewater treatment

High salt concentrations can cause plasmolysis and loss of activity of cells, but the salt-torlerant bacterium can endure the high salt concentrations in wastewater. In this research 7 salt-torlerant bacteria, which could survive in dry powder products and could degrade organic contaminants in saline wastewater, were isolated from a membrane bioreactor. The strain NY6 which showed the fastest growth rate, best property for organic matter degradation and could survive in dry powder more than 3 months was selected and characterized. It was classified as Bacillus aerius based on the analysis of the morphological and physiological properties as well as the 16 S rRNA sequence and Neigh borjoining tree. The strain NY6 could survive in the salinity up to 6% and the optimal growth salinity is2%; it belongs to a slightly halophilic bacterium. The capability of its dry powder products for COD removal was 800 mg COD/(g·day) in synthesized saline wastewater with salinity of 2%. According to salt-tolerant mechanism research, when the salinity was below 2%, the stain NY6 absorbed K+and Na+to maintain osmotic equilibrium, and when the salinity was above 2%, the NY6 kept its life by producing a large amount of spores.     

Characterisation of acute toxicity, genotoxicity and oxidative stress posed by textile effluent on zebrafish

Textile industries are important sources of toxic discharges and contribute enormously to water deterioration, while little attention has been paid to the toxicity of textile effluents in discharge regulation. Bioassays with zebrafish were employed to evaluate the toxicity of wastewater samples collected from different stages at a textile factory and sewage treatment plants (STPs). Physico-chemical parameters, acute toxicity, genotoxicity and oxidative stress biomarkers were analyzed. The wastewater samples from bleaching, rinsing and soaping of the textile factory exhibited high acute toxicity and genotoxicity. The coexisting components of dye compounds, as assistants and oxidants, seemed to cause some effect on the toxic response. After treatment employing the anoxic-oxic (A/O) process in STPs, the color and the chemical oxygen demand (COD) were reduced by 40% and 84%, respectively, falling within the criteria of the Chinese Sewage Discharge Standard. In contrast, increases in acute toxicity and genotoxicity were observed in the anaerobic tank, indicating the formation of toxic intermediates. The genotoxicity of the effluent of the STP was not significantly different from that of the influent, suggesting the wastewater treatment processes were not effective in removing the genotoxicity of the dye wastewater. Results indicated that the effluent contains pro-oxidants since the activities of glutathione (GSH), malondialdehyde (MDA), and total anti-oxidation capacity (T-AOC) were all elevated. In addition, decreases in superoxide dismutase (SOD) and glutathione-S transferase (GST) activities observed can be interpreted as a cytotoxicity sign due to an over-production of reactive oxygen species (ROS). The results of the present study suggest that the STPs were not capable of reducing the toxicity of wastewater sufficiently. Further treatment is needed to remove the potential risks posed by textile effluent to ecosystems and human health, and employing a toxicity index is necessary for discharge regulation.     

Trametes sp.LS-10C产漆酶发酵培养基优化及其漆酶对偶氮染料的脱色性能

为了提高菌株Trametes sp.LS-10C的漆酶产量并初步研究该酶对偶氮染料的脱色性能,本文通过单因素实验及均匀设计对菌株Trametes sp.LS-10C产漆酶培养基进行了优化,获得最优培养基配方为:葡萄糖14.4 g·L~(-1)、豆渣10.1 g·L~(-1)、麸皮100 g·L~(-1)、NH_4Cl_3g·L~(-1)、KH2PO41.4g·L~(-1)、CuSO_4’5H2O 1 g·L~(-1)、NaCl 1 g·L~(-1)、MgSO_40.8 g·L~(-1)、CaCl_20.5 g·L~(-1).菌株发酵至8 d时漆酶产量为595.15 U·m L~(-1),约是优化前的35.66倍.进一步研究表明,该漆酶-介体系统对酸性红GR、酸性蓝40和酸性铬蓝K等3种偶氮染料脱色10 h后脱色率分别高达96.86%、91.28%和86.31%.相比公开发表的文献,本研究所报道的Trametes sp.LS-10C利用优化培养基发酵产漆酶达到了较高水平,具有酶活力高和发酵时间短等特征,且该漆酶在处理偶氮染料废水脱色领域中具有进一步研发和应用价值.     

Pollution of water resources due to industrialization in arid zone of Rajasthan, India

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菌根真菌对环境污染物的降解、转化能力概述

菌根是高等植物与真菌形成的共生体，菌根真菌与许多微生物一样，也能有效的降解，转化的环境污染物，且有其自身的特点和优势。该文综合叙述了国内外在菌根真菌外在苗条奶真菌降解和转化木质素，多氯联苯，除草剂，有毒金属等环境污染物方面的研究进展，显示出菌根真菌是一大类具有较大应用潜力的，不容忽视的微生物群。     

不同共代谢基质对白腐菌降解吲哚的作用研究

选用氨氮、苯酚和喹啉作为吲哚的共代谢基质,通过白腐菌BP对共基质体系的降解研究了白腐菌在秸秆滤出液培养基中对不同共基质体系的代谢过程,并进行了动力学分析,考察了不同共代谢基质物质对白腐菌漆酶分泌和吲哚降解的影响.结果显示,不同降解体系中的白腐菌都可去除99%以上的吲哚.充分的氮源可提高白腐菌的活性和漆酶酶活的峰值;共基质苯酚和喹啉可以增加白腐菌漆酶产量,为吲哚的降解提供较多的电子,同时苯酚和喹啉也能得到较高的去除.在秸秆滤出液中,白腐菌在pH为6～8之间对吲哚都具有较强的降解能力.吲哚在白腐菌的代谢过程中,可能首先在吡啶环的2和3位发生一步羰基化.     

不同白腐真菌复配方式对产酶的影响

通过对1株和由多株白腐真菌复配共同参与下的复合菌产酶量和达到最高酶活所需时间进行比较,筛选出白腐真菌最佳产酶的复配方式.结果表明,青顶拟多孔菌和糙皮侧耳菌两株菌相互发生协同作用,促进漆酶的分泌,产酶量为50.45U·mL-1;青顶拟多孔菌、糙皮侧耳菌和偏肿拟栓菌这3株菌在分泌过程中促进作用大于抑制作用,产酶量最高为75.98U·mL-1;青顶拟多孔菌、糙皮侧耳菌和血红密孔菌三者相互之间出现拮抗作用,产酶量最低为2.91 U·mL-1;实验证明,在白腐真菌之间既存在拮抗作用,也存在协同作用,因此达到最高酶活所用时间也不同.     

壳聚糖铁固定疣孢漆斑菌球处理染料的研究

选择新疆本土产的疣孢漆斑菌作为固定化菌种,并与壳聚糖铁凝胶通过固定化手段有效结合起来,综合分析了壳聚糖铁固定化真菌脱色处理染料的过程机制,以及不同条件下的脱色率.结果表明:固定化真菌对染料的去除首先是染料积累的过程,其次是菌种降解的过程,壳聚糖铁的加入有效缩短了染料积累的时间,24 h的染料脱色率提升了1.5倍;壳聚糖铁固定化真菌对初始浓度为50~250 mg·L-1的酸性染料都有很好的去除效果.振荡培养使疣孢漆斑菌菌球的脱色效率最高提升14.4%.壳聚糖铁固定化菌球投加到染料后有较高的漆酶产量,48 h达到(81.40±3.18)U·mL-1.     

造纸废水的电离辐射预处理工艺研究

造纸废水是我国污染最为严重的难降解工业废水之一,研究了电离辐射处理造纸废水的可行性,探讨了混凝、辐照以及混凝-辐照组合工艺对废纸造纸废水的COD、BOD<,5>、吸光度、DOC以及有机物相对分子质量分布的影响.实验发现,造纸废水的COD主要是由相对分子质量<3 000的有机物构成,相对分子质量为1 000～3 000的...     

白腐真菌组合培养提高漆酶酶活的作用机制研究

采用白腐真菌组合培养的方式提高漆酶酶活,并对组合后菌株相互作用机制进行了研究.菌株55(Trametes trogii)和菌株m-6(Trametes versicolor)组合后漆酶酶活较菌株55和m-6分别提高了24.13倍和4.07倍;组合后菌株间不存在抑制作用;平板培养时,两菌株菌丝生长止于菌丝交界处,该处漆酶酶活最高并分泌褐色色素;液体培养时,菌株m-6对组合后漆酶酶活的提高起着更为重要的作用:向菌株55的培养物中添加菌块m-6,其酶活比向菌株m-6培养物中添加菌块55时的酶活高7.03倍,并且菌株m-6胞外物对菌株55的漆酶分泌也有明显的刺激作用,其中加入20 mL过滤灭菌胞外物可使菌株55漆酶酶活提高6.79倍,而且胞外物高温灭菌后仍能刺激菌株55的漆酶分泌,加入20mL后酶活比对照高4.60倍;Native-PAGE活性染色结果表明组合后同工酶种类未发生变化,但有3种同工酶的浓度升高.     

Electrochemical treatment of olive mill wastewater: Treatment extent and effluent phenolic compounds monitoring using some uncommon analytical tools

Problems related with industrials effluents can be divided in two parts: (1) their toxicity associated to their chemical content which should be removed before discharging the wastewater into the receptor media; (2) and the second part is linked to the difficulties of pollution characterisation and monitoring caused by the complexity of these matrixes. This investigation deals with these two aspects, an electrochemical treatment method of an olive mill wastewater (OMW) under platinized expanded titanium electrodes using a modified Grignard reactor for toxicity removal as well as the exploration of the use of some specific analytical tools to monitor effluent phenolic compounds elimination. The results showed that electrochemical oxidation is able to remove/mitigate the OMW pollution. Indeed, 87% of OMW color was removed and all aromatic compounds were disappeared from the solution by anodic oxidation. Moreover, 55% of the chemical oxygen demand (COD) and the total organic carbon (TOC) were reduced. On the other hand, UV- Visible spectrophotometry, Gaz chromatography/mass spectrometry, cyclic voltammetry and 13 C Nuclear Magnetic Resonance (NMR) showed that the used treatment seems efficaciously to eliminate phenolic compounds from OMW. It was concluded that electrochemical oxidation in a modified Grignard reactor is a promising process for the destruction of all phenolic compounds present in OMW. Among the monitoring analytical tools applied, cyclic voltammetry and 13 C NMR are among the techniques that are introduced for the first time to control the advancement of the OMW treatment and gave a close insight on polyphenols disappearance.     

Design of reaction conditions for the enhancement of microbial degradation of dyes in sequential cycles

The present study evaluated the potential of white-rot fungal strain Coriolus versicolor to decolorize five structurally di erent dyes in sequential batch reactors under optimized conditions. The experiments were run continuously for seven cycles of 8 d each. High decolorizing activity was observed even during the repeated reuse of the fungus, especially when the old medium was replaced with fresh medium after every cycle. Biodegradation was the dominating factor as the fungus was able to produce the enzyme laccase mainly, to mineralize synthetic dyes. The nutrients and composition of the medium played important roles in sustaining the decolorisation potential of the fungus. Corncob was found be an easy and cheap substitute for carbon source for the fungus. Glucose consumption by the fungus was in accordance to its decolorisation activity and chemical oxygen demand (COD) reduction.     

白腐菌对焦化废水中喹啉的降解及机理研究

选用白腐菌BP降解喹啉,研究了白腐菌在不同培养基中对喹啉的降解过程和机理,以及喹啉的降解与白腐菌漆酶活力、生物量比增长速率、培养基pH值的关系。结果显示秸秆滤出液培养基中生长的白腐菌对喹啉具有最高的去除率89%;喹啉的相对去除率与白腐菌漆酶活力、生物量比增长速率具有较好的相关性;白腐菌BP最适pH为6~7;2-羟基喹啉是喹啉降解过程中首先出现的中间产物。