真菌对磺胺二甲氧嘧啶降解过程的转录组分析及差异表达基因的功能分析

采用黄孢原毛平革菌降解磺胺二甲氧嘧啶（SDM）,4 d后SDM的去除率达74%,降解速率达3.24 mg·L^-1·d^-1.采用Illumina高通量测序平台对降解SDM后的菌株与对照组菌株进行测序,通过GO和KEGG富集分析,得到的差异表达基因能显著富集到与降解相关的“氧化还原酶活性”途径,及与应激反应有关的“ABC转运体”路径.通过对高表达高上调的差异表达基因的筛选与分析,得到了耐受和降解SDM的功能基因.水通道蛋白、ABC转运蛋白及甲基转运酶基因等在黄孢原毛平革菌对环境的耐受中起到重要的作用.乙醇氧化酶、细胞色素P450和糖苷水解酶等在黄孢原毛平革菌对SDM的降解中起着关键的作用.本文从转录组水平分析了SDM的降解机制,为黄孢原毛平革菌在环境修复中的应用提供一定的参考.     

染料浓度和盐度对白腐真菌同工酶的电泳分析

应用聚丙烯酰胺凝胶电泳技术分析,并比较了染料废水的两大因子(染料浓度和盐度)对黄孢原毛平革菌过氧化物同工酶谱带的影响程度,结果表明:在染料或盐胁迫下,黄孢原毛平革菌均表现出应急产酶的响应,虽然过氧化物同工酶谱带数量未发生增加或减少,但谱带强度受到较大影响,活性艳红X-3B浓度≤200mg/L或NaCl浓度≤15g/L时均能诱导过量产酶,继续提高染料浓度或盐度将导致产酶抑制,染料浓度对酶带的影响作用高于盐度。     

黄孢原毛平革菌固态发酵产漆酶的研究及应用

对黄孢原毛平革菌（BKMF-1767）利用香蕉皮和玉米棒为发酵底物产胞外漆酶进行了研究.结果表明,当香蕉皮与玉米棒混合比例为1∶2、诱导剂CuSO₄为0.4 mmol/L时,能获得最高漆酶酶活12.68　U/g.利用固态发酵所获得的粗漆酶液,进行了降解五氯酚的试验.在没有氧化还原介体时粗漆酶液能降解PCP,粗酶液中加入5　mmol/L氧化还原介体（ABTS）能获得更高的降解率,反应6 h分别为37.8%和97%.将粗漆酶液用(NH₄)₂SO₄盐析纯化,用提纯后漆酶降解PCP,6 h后降解率为81.8%.     

微量元素对黄孢原毛平革菌降解苯酚的影响

研究了氮源,铁、铜、锰等金属元素以及Tween 80等有机添加剂对黄孢原毛平革菌降解苯酚的影响。结果表明,氮源是黄孢原毛平革菌生长的必需元素,铜元素和锰元素对苯酚降解具有明显的促进作用,而铁元素的促进作用并不显著。各种微量元素的最佳浓度分别为:氮0.1 g/L、铁0.5 mmol/L、锰1.0 mmol/L、铜0.3 mmol/L、Tween 80 0.01 mmol/L。     

接种白腐菌堆肥修复五氯酚污染的土壤

采用4组堆肥装置A、B、C、D,分别往五氯酚污染土壤中不加外来菌、加入固定化黄孢原毛平革菌(Phanerochaete chrysosporium)、加入游离黄孢原毛平革菌及暴露在空气中不做任何处理.对其进行对比研究,探讨了利用堆肥的方法对五氯酚污染土壤进行生物修复的可行性.结果说明,添加黄孢原毛平革菌进行堆肥修复其效果要好于不加菌的效果,经过60d的堆肥,PCP基本得到降解,降解率都达到了94%以上,其中固定化菌又优于游离菌,固定化菌在第9d对PCP的降解率就达到了50%.此外,通过分析种子发芽率,有机质,微生物量碳等多项指标可以看出各组堆肥的腐熟情况都比较理想,为黄孢原毛平革菌降解五氯酚的过程提供了良好的外部环境,使土壤修复与堆肥能较好地结合起来.     

Mn2+在黄杆菌FCN2菌株降解芘过程中的作用研究

利用紫外分光光度法和原子吸收分光光度法研究了Mn²⁺在菌株FCN2生长细胞、悬浮细胞、粗酶液降解芘时的影响作用.在菌体生长期加入0.1～5 mmol/L的Mn²⁺,对菌体的生长及生长量无影响,但对芘的降解均有促进作用,以加入0.1mmol/L的Mn²⁺效果最好,其对芘的平均降解率是对照的1.26倍.此时菌株富集的Mn²⁺为0.025mmol/L;在用无外加Mn²⁺培养的菌株FCN2悬浮细胞降解芘时,加入0.5 mmol/L的Mn²⁺,芘的平均降解率为对照的1.67倍.降解反应发生72h后菌株富集的Mn²⁺为0.18mmol/L;在酶促降解时加入0.1mmol/LMn²⁺,平均降解率为对照的1.30倍.结果表明,在不同时期加入的Mn²⁺对降解芘均有一定的促进作用.     

黄孢原毛平革菌反复脱色模拟染料废水的试验研究

研究了白腐真菌黄孢原毛平革菌在35℃、150r／min条件下培养3d后，培养基类型、染料浓度以及反复脱色次数对其脱色的影响。玉米芯浸出液是首选的可替代营养源的物质，培养3d的黄孢原毛平革菌6h脱色率即达92％。黄孢原毛平革菌能够在短时间(6h)基本脱色较高浓度(40mg／L，60mg／L)的活性艳红K-2BP模拟染料废水，对于低浓度(10mg／L，20mg／L)脱色作用则比较缓慢，浓度超过150mg／L即显示出对菌的毒性作用。玉米芯浸出液培养3d的菌可以重复脱色模拟废水6次以上，每批脱色率均在82％以上，但菌球的沉降性能变差。     

与黄孢原毛平革菌协同降解稻草的混合菌筛选

在纤维素筛选培养基中加入黄孢原毛平革菌稻草固态发酵的浸提液,用这种培养基从自然环境中筛选出与黄孢原毛平革菌相容的菌株,在PDA和MEA平板上进行相容性测试,选择出生长稳定,可以与黄孢原毛平革菌较好共存的6株真菌.考察了6株真菌分别与黄孢原毛平革菌混合培养降解稻草时的酶活和对木质纤维素类组分的降解,筛选出3组更优的组合,其混合培养时,对于纤维素酶能产生较好的协同效果,纤维素降解效果较好.对于木质素降解效率的显著提高,可能是由于发酵体系内的胞外酶和一些活性因子的作用.     

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.     

黄孢原毛平革菌用于煤炭脱硫的特性

研究了表面活性剂Tween80、碳源浓度、初始pH值、孢子浓度和煤浆浓度对黄孢原毛平革菌(Phanerochaete chrysosporium)煤炭脱硫的影响.结果表明,黄孢原毛平革菌具有较强的脱除煤炭中硫的能力.该菌株的最佳脱硫条件为0.5%Tween80,20g/L葡萄糖,10%煤浆,孢子浓度1×10⁵个/mL,pH4.5.在此最佳条件下,第3d的菌丝球生长均匀,生物量最大,第6d的煤样脱硫率达到78.11%.     

Biodegradation of pyrene by Phanerochaete chrysosporium and enzyme activities in soils: Effect of SOM, sterilization and aging

The impacts of soil organic matter （SOM）, aging and sterilization on the production of lignin peroxidase （LIP） and manganese peroxidase （MnP） by Phanerochaete chrysosporium during the biodegradation of pyrene in soils were investigated. The biodegradation of pyrene by P. chrysosporium decreased with increasing SOM content, whereas the maximum activities of LiP and MnP increased, which indicates that SOM outweighed pyrene in controlling enzyme production. Sterilization enhanced the degradation of pyrene due to the elimination of competition from indigenous microbes, whereas aging led to a reduction in the degradation of pyrene primarily through changes in its sorbed forms. Both sterilization and aging could reduce SOM content and alter its structure, which also influenced the bioavailability of pyrene and the enzyme activity. The sterilization and aging processes caused changes in the degradation of pyrene, and the enzyme activities were greater in soils with high SOM contents. MnP was related to the degradation of pyrene to a greater extent, whereas LiP was more related to the decomposition of SOM.     

pH值对白腐真菌液体培养基抑制杂菌效果的影响研究

应用摇瓶试验研究了不同初始pH值对白腐真菌Phanerochaete chrysosporium液体培养基在非灭菌环境抑制杂菌效果的影响.结果表明,当采用Phanerochaete chrysosporium孢子作为种子在非灭菌环境进行培养时,初始pH值为3.6和4.4的液体培养基在培养第1d仅感染酵母菌,而初始pH值为5.6的液体培养基不仅感染了酵母菌而且还感染了细菌;正是由于非灭菌环境培养体系感染杂菌,使得后续Phanerochaete chrysosporium对活性艳红K-2BP的脱色能力大大降低甚至丧失;而采用灭菌环境培养Phanerochaete chrysosporium,非灭菌环境脱色活性艳红K-2BP的方法却获得了较好的脱色效果,3种初始pH值的氮限制液体培养基培养出的Phanerochaete chrysosporium对活性艳红K-2BP 45h的脱色率均在70%以上,接近或超过灭菌环境的结果,其中初始pH值为4.4的液体培养基培养的Phanerochaete chrysosporium在非灭菌环境对活性艳红K-2BP的脱色效果最好,其24h的脱色率达到80%以上.尽管3种pH液体培养基在脱色过程中也同样感染了杂菌,但与非灭菌环境培养体系相比含量很少,没有影响脱色效果.因此,可以得出低pH值(pH=3.6,pH=4.4)氮限制培养基虽然在一定程度上可以抑制细菌,但是却不能抑制酵母菌;当在非灭菌环境使用Phanerochaete chrysosporium脱色活性染料时,Phanerochaete chrysosporium只有在灭菌环境培养至菌丝体形成并在整个系统占优势,才能获得较高的脱色效果.     

白腐真菌木质素降解酶的反应器发酵

为了获得更高的白腐真菌木质素降解酶的产量和相应的控制策略,应用5L搅拌罐生物反应器对氮限制下(C/N=56/2.2)P.chrysosporium产木质素降解酶进行了放大研究.结果表明,在分批发酵试验中,锰过氧化物酶(MnP)和漆酶(Lac)分别在培养第6d和第7d达到峰值,其酶活随时间的变化规律与摇瓶试验基本相同;而采用氮限制液体培养基进行补料没有获得更高的酶活,因此,可以得出采用发酵液体培养基作为补料液不利于白腐真菌持续产酶.另外,在分批发酵和分批补料发酵过程中,均发现体系pH值变化与白腐真菌生长和次生代谢产酶具有较好的相关性,当白腐真菌进入次生代谢阶段开始产酶时,体系pH值开始下降,随着发酵后期酶活的降低,pH值下降的幅度也逐渐变小,当体系酶活接近为0.0U/L时,pH值基本不再变化.因此,在实际发酵过程中,可以依据体系pH的变化间接了解白腐真菌的生长和产酶情况,而分批补料策略还有待于进一步研究.     

铜绿假单胞菌对DBP的降解特性研究

采用小容量全萃取方法,研究了1株铜绿假单胞菌对BDP的降解特性.结果表明,该菌株对DBP具有高效降解能力,当DBP浓度为400 mg/L,投菌量为2 g/L时,t_1/2为3.60　d;其降解过程完全符合一级反应动力学.DBP作为该菌生长的唯一碳源时,其降解过程包括快速生物吸附、解析、降解等几个阶段.实验还确认了存在邻苯二甲酸单丁酯和邻苯二甲酸2种中间产物,从而验证了DBP在双加氧水解酶作用下2步水解变为邻苯二甲酸的历程.     

Influence of glucose feeding on the ligninolytic enzyme production of the white-rot fungus Phanerochaete chrysosporium

The present work studied the influence of glucose feeding on the ligninolytic enzyme production of Phanerochaete chrysosporium in a nitrogen-limited (C/N ratio is 56/8.8 mmol/L) medium. Several sets of shaking flask experiments were conducted. The results showed that 2 g/L glucose feeding on the first day of the culture (24 h after the inoculation) simulated both fungal biomass growth and enzyme production. The manganese peroxidase (MnP) activity was 2.5 times greater than that produced in cultures without glucose feeding. Furthermore, the glucose feeding mode in fed-batch culture was also investigated. Compared to cultures with glucose feeding every 48 h, cultures with glucose feeding of 1.5 g/L (final concentration) every 24 h produced more enzymes. The peak and total yield of MnP activity were 2.7 and 3 times greater compared to the contrast culture, respectively, and the enzyme was kept stable for 4 days with an activity of over 200 U/L. Translated from Acta Scientise Circumstantiae, 2007, 27(3): 363–368 [译自: 环境科学学报]     

Effects of Zn2+ on root growth,cell division, and nucleoli of Allium cepa L.

The effects of different concentrations of Zn²⁺ion on root growth,cell division,and nucleoli of Allium cepa were studied. The test Zn²⁺ ion concentration was made up from zinc sulphate (ZnSO₄. 7H₂O) ranging from 10^-7 to 10^-2 mol/L. The solutions were prepared in tap water (pH =6. 5).The results indicated that Zn²⁺ could obviously inhibit root growth at concentrations from 10^-4)to 10^-2 mol/L.Roots treated with zinc sulphate showed the presence of c-mitosis, anaphase bridges,including sticky and fluidized bridges (at 10^-3 to 10^-2 mol/L) , chromosome stickiness, irregularly shaped nuclei, broken nuclei and micronuclei. A toxicity effect was also observed on the nucleoli using silver staining technique after 48h of treatment with 10^-4to 10^-2 mol/L Zn²⁺, e. g,the nucleolar particulate material scattered around the nucleoli in the nucleus of root tip cells.     

Effects of ferrous and manganese ions on anammox process in sequencing batch biofilm reactors

Ferrous and manganese ions, as essential elements, significantly affect the synthesis of Haem-C, which participates in the energy metabolism and proliferation of anammox bacteria. In this study, two identical sequencing batch biofilm reactors were used to investigate the effects of ferrous and manganese ions on nitrogen removal efficiency and the potential of metal ions serving as electron donor/acceptors in the anammox process. Fluorescence in situ hybridization analysis was applied to investigate the microbial growth. Results showed that the nitrogen removal increased at high concentrations of Fe2＋ and Mn2＋ and the maximum removal efficiency was nearly 95% at Fe2＋ 0.08 mmol/L and Mn2＋ 0.05 mmol/L, which is nearly 15% and 8% higher than at the lowest Fe2＋ and Mn2＋ concentrations （0.04 and 0.0125 mmol/L）. The stabilities of the anammox reactor and the anammox bacterial growth were also enhanced with the elevated Fe2＋ and Mn2＋ concentrations. The Fe2＋ and Mn2＋were consumed by anammox bacteria along with the removal of ammonia and nitrite. Stoichiometry analysis showed Fe2＋ could serve as an electron donor for NO3-N in the anammox process. Nitrate could be reduced with Fe2＋ serving as the electron donor in the anammox system, which causes the value of NO~-N/NH4-N to decrease with the increasing of N-removal efficiency.     

A new method of inhibiting pollutant release from source water reservoir sediment by adding chemical stabilization agents combined with water-lifting aerator

A new method of adding chemical stabilization agents combined with water-lifting aerator can inhibit pollutant release from source water reservoir sediment effectively.