黄孢原毛平革菌过氧化物酶及其对污染物的降解

黄孢原毛平革菌由于其所产胞外过氧化物酶系(主要由木素过氧化物酶和锰过氧化物酶组成)的独特酶降解机理,能降解多种有机污染物,在环境工程中有着巨大的应用前景。通过产酶研究,极大地提高了过氧化物酶活力,并应用于工业化生产。     

铜绿假单胞菌对白腐菌产木质纤维素降解酶的影响

采用固态发酵的方法,考察了两株不同型号的铜绿假单胞菌（AB93066和ATCC9027）对白腐菌（黄孢原毛平革菌）产木质纤维素降解酶（木素过氧化物酶LiP、锰过氧化物酶MnP和羧甲基纤维素酶CMCase）的影响,并对酶提取液的pH值、表面张力及稻草降解残渣中挥发性有机质含量的变化进行了分析.结果表明,添加5.72%的A...     

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.     

黄孢原毛平革菌降解磷酸三苯酯的性能和机理

以白腐真菌的中的黄孢原毛平革菌（Phanerochaete chrysosporium）为实验菌种,考察不同环境条件因素对P.chrysosporium降解磷酸三苯酯（TPhP）的影响以及TPhP降解过程中菌体细胞特性的变化.结果表明,当孢子液的接种量为4%（V/V）,葡萄糖浓度为5g/L,pH值为5~6时,经过6d的处理P.chrysosporium对5mg/L TPhP的降解率可达到60%以上.菌体的细胞色素P450酶在TPhP的降解转化过程中发挥了重要的作用,抑制P450酶的活性会导致TPhP降解率下降.在降解反应的前期,为加快TPhP的代谢转化,菌体胞内蛋白含量以及ATP酶活性出现明显升高.在TPhP胁迫下,菌体SOD和CAT的活性随降解反应的进行呈现先升高后降低的趋势,2种抗氧化酶协同作用维持TPhP降解过程中菌体胞内的氧化还原平衡.     

黄孢原毛平革菌降解磷酸三苯酯的性能和机理

以白腐真菌的中的黄孢原毛平革菌（Phanerochaete chrysosporium）为实验菌种，考察不同环境条件因素对P.chrysosporium降解磷酸三苯酯（TPhP）的影响以及TPhP降解过程中菌体细胞特性的变化.结果表明，当孢子液的接种量为4%（V/V），葡萄糖浓度为5g/L，pH值为5~6时，经过6d的处理P.chrysosporium对5mg/L TPhP的降解率可达到60%以上.菌体的细胞色素P450酶在TPhP的降解转化过程中发挥了重要的作用，抑制P450酶的活性会导致TPhP降解率下降.在降解反应的前期，为加快TPhP的代谢转化，菌体胞内蛋白含量以及ATP酶活性出现明显升高.在TPhP胁迫下，菌体SOD和CAT的活性随降解反应的进行呈现先升高后降低的趋势，2种抗氧化酶协同作用维持TPhP降解过程中菌体胞内的氧化还原平衡.     

白腐真菌发酵中胞外蛋白酶对MnP的产生及其稳定性的影响

在摇瓶试验中通过投加4种对应不同蛋白酶的抑制剂,研究了白腐真菌 Phanerochaete chrysosporium 固定化发酵过程中所产的胞外蛋白酶对其MnP的产生以及稳定性的影响.在培养1d后投加 Pepstatin A 可使MnP峰值提高且提前1d出现,而投加PMSF、EDTA后MnP峰值出现时间不变但峰值皆下降;培养4d后投加 PMSF 和Pepstatin A可使MnP酶活提高且稳定性增强;培养过程中投加 HgCl2 均会抑制菌体生长,使 MnP酶活水平较低.在培养1d后直接补人初级蛋白酶浓缩液.MnP 峰值酶活稍有提高.且第3d补入初级蛋白酶浓缩液会使MnP提前1d出现.在离体条件下,EDTA 和 HgCl2均可抑制MnP酶活;初级蛋白酶和次级蛋白酶均会导致MnP不稳定,但投加 PMSF 和 Pepstatin A 后,MnP稳定性增强.以上结果表明,在培养过程中初级蛋白酶部分组分对MnP的产生过程具有促进作用;初级蛋白酶和次级蛋白酶会导致离体MnP迅速失活,且证实其中2种组分--丝氨酸蛋白酶和天冬氨酸蛋白酶--可导致离体MnP不稳定.     

黄孢原毛平革菌在多种氨氮浓度下木质素降解酶的产生

在氨氮浓度0．0308-0．924g／L，下对黄孢原毛平革菌(Phanerochaete chrysosporium)在空气环境中进行自由悬浮振荡培养，在氨氮浓度0．0308-0．308g／L下可检测到木质素过氧化物酶活性，最高酶活为42．8U/L；在氨氮浓度0．0308g／L和0．154g/L下可检测到漆酶活性，最高酶活为35．0U／L，在氨氮浓度不低于0．154g/L时，葡萄糖消耗速率大致相当，明显高于在氨氮浓度0．0308g／L下的葡萄糖消耗速率；氨氮在葡萄糖耗尽时达到最低值，然后开始增大；木质素过氧化物酶和漆酶的活性峰与葡萄糖和氨氮的最大消耗基本对应。实验结果对木质素降解酶发酵和白腐真菌在环境工程中的直接应用具有启发意义。     

交替处理不同废水对白腐真菌处理体系的影响研究

白腐真菌反应器的连续运行是否与木质素过氧化物酶系直接相关是其用于处理难降解有机废水的关键问题。针对此问题,构建白腐真菌处理体系对垃圾渗滤液和焦化废水被交替处理（序批式运行）,考察交替处理过程中白腐真菌处理体系的变化。结果显示：在交替处理过程中,黄孢原毛平革菌(Phanerochaete chrysosporium)好氧丝状生物膜并未出现明显的适应期,能够连续合成木质素过氧化物酶（56～376 U/L）;每批废水的pH都表现为由碱性向酸性变化;COD、氨氮和磷酸盐的去除未受废水交替处理的影响,且在垃圾渗滤液中分别达到43%～44%、70%～71%和17%～25%的去除率,在焦化废水中分别达到26%、33%和57%的去除率。表明基于P. chrysosporium好氧丝状生物膜构建的难降解有机废水处理体系是以木质素过氧化物酶系为基础,可能与难降解废水的种类无关。     

木质素过氧化物酶和锰过氧化物酶对染料脱色的性能比较

通过控制培养基中Mn2+的浓度获得只含有木质素过氧化物酶(LiP)或锰过氧化物酶(MnP)的单一酶培养物,用于比较LiP和MnP对染料降解脱色的条件和能力的差异.结果表明,LiP对橙Ⅰ降解脱色的最佳条件为h2O₂0.15 mmol/L,pH 3.0,温度40 ℃;MnP为h2O₂0.15 mmol/L,pH 3.5,温度40 ℃.最佳条件下,考察LiP和MnP作用下染料浓度和染料类型对脱色的影响,发现LiP作用下脱色率明显高于MnP作用下的脱色率,表明LiP可作用的染料浓度比MnP高,可作用的染料范围比MnP大.由此认为LiP具有比MnP更强的脱色能力.      

遗传工程菌Fhhh降解精对苯二甲酸与mnp基因表达

跨界融合构建的遗传工程菌Fhhh及其亲株黄孢显毛平革菌 (PC) ,降解精对苯二甲酸的比降解率受到Mn2 + 、酒石酸铵、H2 O2 、pH共 4因素的影响 .除pH值外 ,其余 3个因素影响 2菌株比降解率大小的排序完全一致 .pH值对PC菌的影响排序处于第 3位 ,对Fhhh则处于第 1位 .Fhhh比降解率比PC高出 11 11% ;mnp基因表达的锰过氧化物酶 (MnP)比活力水平比PC高出 15 2 2 % .降解精对苯二甲酸 4因素优化水平 ,也是mnp基因表达的优化条件 .比降解率与MnP的比活力水平之间有显著或极显著正相关性 (r>r0 .0 5( 4) ,r >r0 .0 1( 4) ) .研究结果为高效处理精对苯二甲酸废水提供了重要的分子生物学依据     

白腐真菌F2的生长及产木质素降解酶特性的研究

考察了从我国生物资源中筛分出的白腐真菌F2的生长特性,采用多因素试验法研究了F2菌产木质素降解酶的特性;用统计学方法对试验数据进行了误差分析,并分析了多种影响因素对F2菌产木质素降解酶的影响.实验结果表明:F2菌在PDA培养基平板上和Tien＆Kirk培养基中都生长良好且生长速率较高;在自由悬浮振荡培养(不通氧气)条件下,F2菌产LiP的最高酶活可达60 5U·L-1,MnP的最高酶活可达263 4U·L-1,其产酶能力超过了黄孢原毛平革菌在自由悬浮振荡培养(不另外通入氧气)条件下的产酶能力.本研究还发现向培养基中添加的Cu2+浓度超过1μmol·L-1时会抑制F2菌产LiP,以往的文献未报道过Cu2+的这种抑制作用.     

木质素降解酶对四环素的降解可行性

选取了使用广泛、在环境中残留量大、生物毒性大、不易被生物降解的四环素类抗生素中的四环素,考察了其被木质素过氧化物酶(LiP)和锰过氧化物酶(MnP)粗酶液体外降解的效果,证明2种酶对四环素均有较强的降解作用,并在此基础上比较了3个不同酶活(15 U·L-1、40U·L-1、70 U·L-1)下的降解率.结果表明,同等酶活(40 U·L-1)下,LiP比MnP的降解能力强,在适宜的反应条件下,LiP对50 mg·L-1四环素的降解率在5min内可达95%以上,而MnP在2h后仅达70%.对于LiP,当酶活从15 U·L-1升高至40 U·L-1时,降解率提高约15%,当酶活进一步升高至70 U·L-1时,降解率变化不大,而提高酶活可明显提高MnP对四环素的降解率.此外,通过反应进程中补加H2O2,可以明显提高MnP对四环素的降解率.     

氟化氢对植物抗氧化酶活性的影响

采用人工熏气方法研究ＨＦ污染条件下大豆和菜豆叶片中４种抗氧化酶的活性变化，结果表明它们对氟的敏感性差异很大：超氧化物歧化酶最为敏感，抗坏血酸过氧化物酶和非特异性过氧化物酶次之，而过氧化氢酶活性基本无变化，就两种供试植物而言，大豆的抗氧化酶对氟更为敏感；就植物生长阶段而言，开花期的抗氧化酶对氟的敏感性较苗期为大。在此基础上提出，氟污染环境中植物ＳＯＤ、Ａ－ＰＯＤ和Ｎ－ＰＯＤ的活性受抑与植物氟害有关。     

Cooperation between ligninolytic enzymes produced by superior mixed flora

Since the ability to degrade lignin with one kind of white-rot fungi or bacteria was very limited, superior mixed flora‘s ability to degrade lignin was investigated by an orthogonal experiment in this paper. The results showed that superior mixed flora reinforced the ability to degrade lignin, the degradation rates of both sample 9 and 10 were beyond 80% on the day 9. The cooperation between lignin peroxidase(LiP), Mn-dependent peroxidase(MnP) and laccase (Lac) for lignin degradation was also studied. By examining the activities of three enzymes produced by superior mixed flora, it was found that Lac was a key enzyme in the process of biological degradation of lignin but Lip was not; the enzyme activity ratios of Lac/MnP and Lac/LiP were significantly correlative with the degradation rate of lignin at the 0.01 level; and the ratio of MnP/LiP was an important factor affecting the degradation rate of lignin.     

木质素降解酶研究进展与外生菌根真菌

综述了木质素降解酶系统的组成、分子生物学研究和主要影响因子的研究进展,以及国内外在外生菌根真菌产木质素降解酶方面的研究,阐述了其在有机污染土壤修复中的优势。木质素降解酶系统能够降解多环芳烃、氯代芳烃、硝基有机物和染料等多种环境污染物。许多外生菌根真菌都具有木质素降解酶系统。     

Ultraviolet irradiation induced oxidative stress and response of antioxidant system in an intertidal macroalgae Corallina officinalis L.

The response of the antioxidant defense system of an intertidal macroalgae Corallina officinalis L. to different dosages of UV-B irradiation was investigated. Results showed that superoxide dimutase (SOD) and peroxidase (POX) increased and then maintained at a relatively stable level when subjected to UV-B irradiation. Catalase (CAT) activity under medium dosage of UV-B irradiation (Muv) and high dosage of UV-B irradiation (Huv) treatments were significantly decreased. Ascorbate peroxidase (APX) activity first remained unaltered and then increased in Huv treatment. In addition, the assay on isozymes was carried out using non-denaturing polyacrylamide gel electrophoresis (PAGE). The activities of some SOD isoforms were altered by UV-B. Two new bands (POX V and POX Ⅶ) appeared upon exposure to all three UV-B dosages. CAT Ⅲ activity was increased by low dosage of UV-B irradiation (Luv),whereas CAT Ⅲ and CAT Ⅳ disappeared when the alga was exposed to Muv and Huv. Two bands of APX (APX Ⅵ and APX Ⅶ)were increased and a new band (APX X) was observed under Huv exposure. H2O2 and thiobarbituric acid reacting substance (TBARS)increased under Muv and Huv treatments. Overall, UV-B protection mechanisms are partly inducible and to a certain extent sufficient to prevent the accumulation of damage in C officinalis.     

Effect of heavy metals and phenol on bacterial decolourisation and COD reduction of sucrose-aspartic acid Maillard product

Melanodins are amino-carbonyl complex, predominantly present in sugarcane molasses based distillery wastewater as major source of colourant. The microbial decolourisation of melanoidin is a challenge due to its binding property with other co-pollutants of distillery waste. Results revealed that the presence of Zn2+ (2.00-20.00 mg/L) in melanoidin solution (1200 mg/L) stimulated the bacterial growth and sucrose-aspartic acid Maillard product (SAA) decolourisation as compared to control, while Fe 3+ and Mn2+ at the same concentration inhibited the process. However, the presence of phenol (100 mg/L) along with Zn2+ , Fe3+ and Mn2+ suppressed the bacterial growth, SAA decolourisation and MnP activity. The shrinkage and reduced number of bacterial cell count at higher concentration of heavy metals in presence of phenol was also observed under scanning electron microscope.     

白腐真菌培养条件对其分泌木质素降解酶的影响

应用摇瓶试验研究了不同白腐真菌培养条件对其产酶的影响.通过控制不同转速、投加载体等方式考察了白腐真菌的产酶情况.结果表明,在悬浮培养方式下,转速为160r/min时获得的锰过氧化物酶最高(481.6U/L),其酶活是静置、120r/min条件下培养的65倍和43倍;投加载体后,载体固定化培养获得的木质素过氧化物酶酶活是悬浮培养的71倍,载体投加量对其产酶影响很大,只有当载体处于非浸没状态时才有利于酶活产生,否则酶活极低.因此,选择载体固定化—非浸没—振荡培养方式培养白腐真菌可获得更高的产酶量和酶活.     

Ultraviolet irradiation induced oxidative stress and response of antioxidant system in an intertidal macroalgae Corallina o cinalis L.

The response of the antioxidant defense system of an intertidal macroalgae Corallina officinalis L. to different dosages of UV-B irradiation was investigated. Results showed that superoxide dimutase (SOD) and peroxidase (POX) increased and then maintained at a relatively stable level when subjected to UV-B irradiation. Catalase (CAT) activity under medium dosage of UV-B irradiation (Muv) and high dosage of UV-B irradiation (Huv) treatments were significantly decreased. Ascorbate peroxidase (APX) activity first remained unaltered and then increased in Huv treatment. In addition, the assay on isozymes was carried out using non-denaturing polyacrylamide gel electrophoresis (PAGE). The activities of some SOD isoforms were altered by UV-B. Two new bands (POX V and POX Ⅶ) appeared upon exposure to all three UV-B dosages. CAT Ⅲ activity was increased by low dosage of UV-B irradiation (Luv),whereas CAT Ⅲ and CAT Ⅳ disappeared when the alga was exposed to Muv and Huv. Two bands of APX (APX Ⅵ and APX Ⅶ)were increased and a new band (APX X) was observed under Huv exposure. H2O2 and thiobarbituric acid reacting substance (TBARS)increased under Muv and Huv treatments. Overall, UV-B protection mechanisms are partly inducible and to a certain extent sufficient to prevent the accumulation of damage in C officinalis.