细菌脱色酶TpmD对三苯基甲烷类染料脱色的酶学特性研究

从嗜水气单胞菌DN322中分离纯化出能够对三苯基甲烷类染料结晶紫、碱性品红、灿烂绿及孔雀绿进行有效脱色的脱色酶,命名为TpmD。该酶的亚基分子量为29.4kDa,等电点为5.6。该酶催化上述4种三苯基甲烷类染料脱色反应的适合温度为40~60℃,适合pH范围为5.5~9.0。动力学参数测定结果显示TpmD对结晶紫、碱性品红、灿烂绿及孔雀绿的Km值分别为24.3、40.65、4.2、68.5μmol-1.L-1,Vmax值分别为19.6、74.1、82.8、115.6μmol.L-1.s-1。结晶紫为该酶的最适反应底物。TpmD催化的脱色反应依懒于NADH/NADPH及分子氧的存在,显示该酶属于NADH/NADPH依赖型的氧化酶类。这是国内外首次关于细菌中三苯基甲烷类染料脱色酶酶学性质的描述。     

微生物对三苯基甲烷类染料脱色的研究进展

三苯基甲烷染料广泛应用于纺织印染、医药、生物染色、造纸、皮革、食品及化妆品等领域, 常见的有作为抗菌剂的孔雀石绿和结晶紫等。由于其特殊的化学结构, 在环境中较稳定且难以降解脱色, 因此其生物脱色降解的研究可为印染废水处理和染料污染环境的生物修复提供理论依据。本文从细菌、放线菌、真菌及藻类等微生物对三苯基甲烷类染料降解脱色研究新进展做综述。通过分析不同微生物脱色三苯基甲烷类染料的中间产物来探讨其降解机理和降解途径, 同时论及功能酶的分离纯化、酶学特性及其编码基因的克隆表达新进展, 并分别从基础理论和应用两方面对微生物降解三苯基甲烷类染料未来的研究方向进行了展望。     

Biodegradation of leuco derivatives of triphenylmethane dyes by <Emphasis Type="Italic">Sphingomonas</Emphasis> sp. CM9

A leuco derivatives of triphenylmethane dyes degrading bacterium, strain CM9, was isolated from an aquafarm field. Based on morphology, physiologic tests, 16S rDNA sequence, and phylogenetic characteristics, it was identified as Sphingomonas sp. This strain was capable of degrading leucomalachite green (LMG), leucocrystal violet and leucobasic fuchsin completely. The relationship between bacterium growth and LMG degradation suggested that strain CM9 could use LMG as the sole source of carbon. The most LMG degradation activity of CM9 crude extract was observed at pH 7.0 and at 30°C. Many metal ions had little inhibition effect on the degradation activity of the crude extract. CM9 also showed strong decolorization of triphenylmethane dyes to their leuco derivatives. GC/MS analysis detected two novel metabolic products, methylbenzene and 4-aminophenol, during the LMG degradation by CM9.     

胶红酵母JB401降解脱色三苯甲烷类染料

从烟梗中分离筛选得到1株能够对三苯甲烷类染料高效脱色的微生物,经ITS-5.8S rDNA分析鉴定为胶红酵母,命名为Rhodotorula mucilaginosa JB401。全波长扫描实验结果证实染料的脱色由胶红酵母降解结晶紫引起。为了提高R.mucilaginosa JB401脱色结晶紫的能力,通过单因素试验对R.mucilaginosa JB401的培养条件进行了优化,得出菌体生长24 h后以2%接种量接入初始pH为5的脱色培养基并在37℃摇床培养,可以取得最优脱色效果,此时脱色50、100和200 mg/L的结晶紫达到90%去除率分别需要3、6和14 h。此外,胶红酵母对温度和pH良好的适应性使其具有应用于工业废水处理的潜力。     

Decolorization of triphenylmethane, azo, and anthraquinone dyes by a newly isolated Aeromonas hydrophila strain

A broad-spectrum dye-decolorizing bacterium, strain DN322, was isolated from activated sludge of a textile printing wastewater treatment plant. The strain was characterized and identified as a member of Aeromonas hydrophila based on Gram staining, morphology characters, biochemical tests, and nearly complete sequence analysis of 16S rRNA gene and the gyrase subunit beta gene (gyrB). Strain DN322 decolorized a variety of synthetic dyes, including triphenylmethane, azo, and anthraquinone dyes. For color removal, the most suitable pH and temperature were pH 5.0–10.0 and 25–37°C, respectively. Triphenylmethane dye, e.g., Crystal Violet, Basic Fuchsin, Brilliant Green, and Malachite Green (50 mg l⁻¹) were decolorized more than 90% within 10 h under aerobic culture condition and Crystal Violet could be used as sole carbon source and energy source for cell growth. The color removal of triphenylmethane dyes was due to a soluble cytosolic enzyme, and the enzyme was an NADH/NADPH-dependent oxygenase; For azo and anthraquinone dyes, e.g., Acid Amaranth, Great Red GR, Reactive Red KE-3B, and Reactive Brilliant Blue K-GR (50 mg l⁻¹) could be decolorized more than 85% within 36 h under anoxic condition. This strain may be useful for bioremediation applications.     

IncP-1-beta plasmid pGNB1 isolated from a bacterial community from a wastewater treatment plant mediates decolorization of triphenylmethane dyes

Plasmid pGNB1 was isolated from bacteria residing in the activated sludge compartment of a wastewater treatment plant by using a transformation-based approach. This 60-kb plasmid confers resistance to the triphenylmethane dye crystal violet and enables its host bacterium to decolorize crystal violet. Partial sequencing of pGNB1 revealed that its backbone is very similar to that of previously sequenced IncP-1beta plasmids. The two accessory regions of the plasmid, one located downstream of the replication initiation gene trfA and the other located between the conjugative transfer modules Tra and Trb, were completely sequenced. Accessory region L1 contains a transposon related to Tn5501 and a gene encoding a Cupin 2 conserved barrel protein with an unknown function. The triphenylmethane reductase gene tmr and a truncated dihydrolipoamide dehydrogenase gene that is flanked by IS1071 and another putative insertion element were identified in accessory region L2. Subcloning of the pGNB1 tmr gene demonstrated that this gene is responsible for the observed crystal violet resistance phenotype and mediates decolorization of the triphenylmethane dyes crystal violet, malachite green, and basic fuchsin. Plasmid pGNB1 and the associated phenotype are transferable to the alpha-proteobacterium Sinorhizobium meliloti and the gamma-proteobacterium Escherichia coli. This is the first report of a promiscuous IncP-1beta plasmid isolated from the bacterial community from a wastewater treatment plant that harbors a triphenylmethane reductase gene. The pGNB1-encoded enzyme activity is discussed with respect to bioremediation of sewage polluted with triphenylmethane dyes.     

IncP-1β Plasmid pGNB1 Isolated from a Bacterial Community from a Wastewater Treatment Plant Mediates Decolorization of Triphenylmethane Dyes

Plasmid pGNB1 was isolated from bacteria residing in the activated sludge compartment of a wastewater treatment plant by using a transformation-based approach. This 60-kb plasmid confers resistance to the triphenylmethane dye crystal violet and enables its host bacterium to decolorize crystal violet. Partial sequencing of pGNB1 revealed that its backbone is very similar to that of previously sequenced IncP-1β plasmids. The two accessory regions of the plasmid, one located downstream of the replication initiation gene trfA and the other located between the conjugative transfer modules Tra and Trb, were completely sequenced. Accessory region L1 contains a transposon related to Tn5501 and a gene encoding a Cupin 2 conserved barrel protein with an unknown function. The triphenylmethane reductase gene tmr and a truncated dihydrolipoamide dehydrogenase gene that is flanked by IS1071 and another putative insertion element were identified in accessory region L2. Subcloning of the pGNB1 tmr gene demonstrated that this gene is responsible for the observed crystal violet resistance phenotype and mediates decolorization of the triphenylmethane dyes crystal violet, malachite green, and basic fuchsin. Plasmid pGNB1 and the associated phenotype are transferable to the α-proteobacterium Sinorhizobium meliloti and the γ-proteobacterium Escherichia coli. This is the first report of a promiscuous IncP-1β plasmid isolated from the bacterial community from a wastewater treatment plant that harbors a triphenylmethane reductase gene. The pGNB1-encoded enzyme activity is discussed with respect to bioremediation of sewage polluted with triphenylmethane dyes.     

Particle beam liquid chromatography-mass spectrometry of triphenylmethane dyes: application to confirmation of malachite green in incurred catfish tissue

Eight triphenylmethane dyes (malachite green, leucomalachite green, gentian violet, leucogentian violet, brilliant green, pentamethyl gentian violet, N′,N′-tetramethyl gentian violet and N′,N″-tetramethyl gentian violet) have been characterized by particle beam liquid chromatography-mass spectrometry. The electron ionization spectra obtained of these dyes by this technique exhibit similar fragmentation, with the formation of phenyl and substituted phenyl radicals, and loss of alkyl groups from the amines. It was observed that the six cationic dyes are reduced in the mass spectrometer source to form the corresponding leuco compounds. This technique was evaluated for the confirmation of malachite green and leucomalachite green in incurred catfish (Ictalurus punctatus) muscle tissue.     

Phytoremediation of triphenylmethane dyes by overexpressing a Citrobacter sp. triphenylmethane reductase in transgenic Arabidopsis

Triphenylmethane dyes are extensively utilized in textile industries, medicinal products, biological stains, and food processing industries, etc. They are generally considered as xenobiotic compounds, which are very recalcitrant to biodegradation. The widespread persistence of such compounds has generated concerns with regard to remediation of them because of their potential carcinogenicity, teratogenicity, and mutagenicity. In this study, we present a system of phytoremediation by Arabidopsis plants developed on the basis of overexpression of triphenylmethane reductase (TMR) from the Citrobacter sp. The morphology and growth of TMR transgenic Arabidopsis plants showed significantly enhanced tolerances to crystal violet (CV) and malachite green (MG). Further, HPLC and HPLC–MS analyses of samples before and after dye decolorization in culture media revealed that TMR transgenic plants exhibited strikingly higher capabilities of removing CV from their media and high efficiencies of converting CV to non-toxic leucocrystal violet (LCV). This work indicates that microbial degradative gene may be transgenically exploited in plants for bioremediation of triphenylmethane dyes in the environment.     

毛木耳对孔雀石绿染料降解条件的优化

随着我国印染工业的发展,废水对生态环境的危害日趋严重,亟需开发一种脱色明显且成本低廉的降解方法。本研究发现毛木耳Auricularia cornea菌株AC5对不同结构的染料均具有一定的降解作用,尤其是三苯甲烷类染料。利用26℃、160r/min振荡培养7d的粗酶液对染料（75.0mg/L）进行12h降解,结果显示三苯甲烷染料孔雀石绿、结晶紫,蒽醌染料活性蓝19和偶氮染料活性蓝222的降解效率分别为83.27%、71.77%、67.81%和63.92%。染料降解实验和酶活力测定结果表明,毛木耳对孔雀石绿的降解率达到最高时漆酶活性最高,为321.0U/mL,木质素过氧化物酶和锰过氧化物酶活性较低。因此,推测在降解过程中漆酶起到主要作用。研究表明利用毛木耳菌丝发酵液降解染料废水成本低且操作方便,为染料废水的降解研究提供了前期基础。     

Decolorization of azo and triphenylmethane dyes by Pycnoporus sanguineus producing laccase as the sole phenoloxidase

Partial decolorization of two azo dyes (orange G and amaranth) and complete decolorization of two triphenylmethane dyes (bromophenol blue and malachite green) was achieved by cultures in submerged liquid culture producing laccase as the sole phenoloxidase. Enzyme production could be correlated with dye decolorization, with sorption of dye to mycelia accounting for less than 3% of dye removal.     

Study of dye decolorization in an immobilized laccase enzyme-reactor using online spectroscopy

Decolorization of textile dyes by a laccase from Trametes modesta immobilized on gamma-aluminum oxide pellets was studied. An enzyme reactor was equipped with various UV/Vis spectroscopic sensors allowing the continuous online monitoring of the decolorization reactions. Decolorization of the dye solutions was followed via an immersion transmission probe. Adsorption processes were observed using diffuse reflectance measurements of the solid carrier material. Generally, immobilization of the laccase does not seem to sterically affect dye decolorization. A range of commercial textile dyes was screened for decolorization and it was found that the application of this enzymatic remediation system is not limited to a certain structural group of dyes. Anthrachinonic dyes (Lanaset Blue 2R, Terasil Pink 2GLA), some azo dyes, Indigo Carmine, and the triphenylmethane dye Crystal Violet were efficiently decolorized. However, the laccase displayed pronounced substrate specificities when a range of structurally related model azodyes was subjected to the biotransformation. Azodyes containing hydroxy groups in ortho or para position relative to the azo bond were preferentially oxidized. The reactor performance was studied more closely using Indigo Carmine.     

White-rot fungus <Emphasis Type="Italic">Ganoderma</Emphasis> sp.En3 had a strong ability to decolorize and tolerate the anthraquinone,indigo and triphenylmethane dye with high concentrations

The ability of the white-rot fungus Ganoderma sp.En3 to decolorize different kinds of dyes widely applied in the textile and dyeing industry, including the anthraquinone dye Remazol Brilliant Blue R (RBBR), indigo dye indigo carmine and triphenylmethane dye methyl green, was evaluated in this study. Ganoderma sp.En3 had a strong capability of decolorizing high concentrations of RBBR, indigo carmine and methyl green. Obvious reduction of Chemical Oxygen Demand was observed after decolorization of different dyes. Ganoderma sp.En3 had a strong ability to tolerate RBBR, indigo carmine and methyl green with high concentrations. High concentrations of RBBR, indigo carmine and methyl green could also be efficiently decolorized by the crude enzyme of Ganoderma sp.En3. Different redox mediators such as syringaldehyde, acetosyringone and acetovanillone could enhance the decolorization capability for higher concentration of indigo carmine and methyl green. Different metal ions had little effect on the ability of the crude enzyme to decolorize indigo carmine and methyl green. Our study suggested that Ganoderma sp.En3 had a strong capability for decolorizing and tolerating high concentrations of different types of dyes such as RBBR, indigo carmine and methyl green.     

The Mechanism of the Gram Reaction I. The Specificity of the Primary Dye

Dyes of all major types were tested for their suitability as the primary dye in the Gram stain. When a counterstain was not used, some dyes of all types were found to differentiate Gram-positive from Gram-negative organisms. When a counterstain was used, these dyes were found to vary greatly in their suitability. Those dyes found to be good substitutes for crystal violet were: Brilliant green, malachite green, basic fuchsin, ethyl violet, Hoffmann's violet, methyl violet B, and Victoria blue R. All are basic triphenylmethane dyes. Acid dyes were generally not suitable. Differences in the reaction of Gram-positive and Gram-negative cells to Gram staining without the use of iodine were observed and discussed but a practical differentiation could not be achieved in this manner. Certain broad aspects of the chemical mechanism of dyes in the gram stain are discussed.     

Decolorization of synthetic dyes by solid state cultures of Lentinula (Lentinus) edodes producing manganese peroxidase as the main ligninolytic enzyme

The ability of the white-rot fungus Lentinula (Lentinus) edodes to decolorize several synthetic dyes was investigated using solid state cultures with corn cob as substrate. Cultures, containing amido black, congo red, trypan blue, methyl green, remazol brilliant blue R, methyl violet, ethyl violet and Poly R478 at 200 ppm, were completely decolorized after 18 days of incubation. Partial decolorization was observed in the cultures containing 200 ppm of brilliant cresyl blue and methylene blue. High manganese peroxidase activity (2600 U/g substrate), but very low lignin peroxidase (<10 U/g substrate) and laccase (<16 U/g substrate) activities were detected in the cultures. In vitro, the dye decolorization was markedly decreased by the absence of manganic ions and H2O2. These data suggest that manganese peroxidase appear to be the main responsible for the capability of L. edodes to decolorize synthetic dyes.     

Triphenylmethane reductase from Citrobacter sp. strain KCTC 18061P: purification, characterization, gene cloning, and overexpression of a functional protein in Escherichia coli

We purified to homogeneity an enzyme from Citrobacter sp. strain KCTC 18061P capable of decolorizing triphenylmethane dyes. The native form of the enzyme was identified as a homodimer with a subunit molecular mass of about 31 kDa. It catalyzes the NADH-dependent reduction of triphenylmethane dyes, with remarkable substrate specificity related to dye structure. Maximal enzyme activity occurred at pH 9.0 and 60 degrees C. The enzymatic reaction product of the triphenylmethane dye crystal violet was identified as its leuco form by UV-visible spectral changes and thin-layer chromatography. A gene encoding this enzyme was isolated based on its N-terminal and internal amino acid sequences. The nucleotide sequence of the gene has a single open reading frame encoding 287 amino acids with a predicted molecular mass of 30,954 Da. Although the deduced amino acid sequence displays 99% identity to the hypothetical protein from Listeria monocytogenes strain 4b H7858, it shows no overall functional similarity to any known protein in the public databases. At the N terminus, the amino acid sequence has high homology to sequences of NAD(P)H-dependent enzymes containing the dinucleotide-binding motif GXXGXXG. The enzyme was heterologously expressed in Escherichia coli, and the purified recombinant enzyme showed characteristics similar to those of the native enzyme. This is the first report of a triphenylmethane reductase characterized from any organism.     

Triphenylmethane Reductase from Citrobacter sp. Strain KCTC 18061P: Purification, Characterization, Gene Cloning, and Overexpression of a Functional Protein in Escherichia coli

We purified to homogeneity an enzyme from Citrobacter sp. strain KCTC 18061P capable of decolorizing triphenylmethane dyes. The native form of the enzyme was identified as a homodimer with a subunit molecular mass of about 31 kDa. It catalyzes the NADH-dependent reduction of triphenylmethane dyes, with remarkable substrate specificity related to dye structure. Maximal enzyme activity occurred at pH 9.0 and 60°C. The enzymatic reaction product of the triphenylmethane dye crystal violet was identified as its leuco form by UV-visible spectral changes and thin-layer chromatography. A gene encoding this enzyme was isolated based on its N-terminal and internal amino acid sequences. The nucleotide sequence of the gene has a single open reading frame encoding 287 amino acids with a predicted molecular mass of 30,954 Da. Although the deduced amino acid sequence displays 99% identity to the hypothetical protein from Listeria monocytogenes strain 4b H7858, it shows no overall functional similarity to any known protein in the public databases. At the N terminus, the amino acid sequence has high homology to sequences of NAD(P)H-dependent enzymes containing the dinucleotide-binding motif GXXGXXG. The enzyme was heterologously expressed in Escherichia coli, and the purified recombinant enzyme showed characteristics similar to those of the native enzyme. This is the first report of a triphenylmethane reductase characterized from any organism.     

Methods for the Standardization of Biological Stains: Part IV

In this paper are given methods for determining the suitability of certain dyes of the triphenylmethane group for certification by the Commission on Standardization of Biological Stains. These methods have been developed by the Commission, in cooperation with the Color and Farm Waste Division, Bureau of Chemistry and Soils, U. S. Department of Agriculture. The dyes for which the methods are given in the present paper are: Malachite green, brilliant green, light green SF yellowish, fast green FCF, basic fuchsin (rosanilin and pararosanilin), acid fuchsia, methyl violet, crystal violet, gentian violet, methyl green and anilin blue. For each of these dyes, methods are discussed under the following headings: (1) identification or qualitative examination; (2) quantitative analysis; and (3) biological tests.     

白囊耙齿菌对茜素红脱色条件优化及其毒性变化检测

白囊耙齿菌Irpex lacteus是分离自倒木上的一株可以分泌漆酶和锰过氧化物酶的白腐真菌。利用I. lacteus对固体条件下的活性黑、活性红、结晶紫、茜素红和孔雀石绿进行脱色能力的检测,通过单因素和正交试验优化I. lacteus对茜素红的脱色条件,并以3种作物发芽率为指标测定茜素红被I. lacteus脱色前后的毒性变化。结果显示,I. lacteus对5种染料均可脱色,其中对茜素红染料的脱色更为彻底;单因素和正交试验优化I. lacteus对茜素红的脱色条件为：pH 7.0、葡萄糖10.0g/L、硫酸铵0.66g/L、接种量2片（Φ=8.0mm）、100.0mL三角瓶装液20.0mL,优化条件下I. lacteus对茜素红脱色10d时的脱色率为88.26%,与未优化前的脱色率相比提高了60.50%;茜素红染料被I. lacteus脱色前后毒性大小排序为：染料原液>染料脱色后>PDB培养基处理,表明茜素红染料存在一定的毒性,I. lacteus脱色茜素红后可以使其毒性减弱。通过本研究,为I. lacteus在茜素红等染料废水脱色以及降低染料废水毒性方面的应用奠定基础。     

Decolorization of 1:2 metal complex dye Acid blue 193 by a newly isolated fungus, Cladosporium cladosporioides

Summary A fungus Cladosporium cladosporioides isolated from coal sample as a decolorizing microorganism. It decolorized five different azo and triphenylmethane dyes like acid blue 193, acid black 210, crystal violet, reactive black B(S) and reactive black BL/LPR both on solid and in liquid broth medium. Culture broth of this fungus decolorized completely 100 mg of acid blue 193 l⁻¹ in 8 days. The extracellular enzyme of Cladosporium cladosporioides decolorized acid blue 193 on repeated addition to a total (out of 700 mg l⁻¹) concentration of 564 mg l⁻¹ within 168 h without significant decline in the activity, showing the resistant property of Cladosporium cladosporioides to a high concentration of the dye. The optimal temperature 40 °C, pH 5.6 and sugar concentration of 4% required for decolorization of acid blue 193. Cladosporium cladosporioides showed manganese peroxidase activity with 41 U l⁻¹, laccase activity with 1413 U l⁻¹ and lignin peroxidase activity was negligible after day 8 of incubation.