Synthetic Dyes Research Articles

BOLD: Color from Test Tube to Textile

Abstract Red can be the color of passion and danger, or luck and prosperity. Blue can be the shade of sadness—singing the blues—or a sign of tranquility and serenity. As the Russian painter Wassily Kandinsky once affirmed, in his 1911 treatise Concerning the Spiritual in Art , “Color is a power which directly influences the soul.” Color is also culture: we’ve colored our environments, clothes, and bodies for thousands of years, since early humans applied simple organic stains derived from the plants around them. The art and science of dyeing is an ancient one; today it’s an economic and commercial powerhouse. The arrival of the first synthetic dyes in the 1850s—discovered by happenstance from experiments with coal tar waste—brought us a rainbow of new possibilities for fashion and textiles, from color “fads” and trends to new means for self-expression. But synthetic color’s dark side lingers in polluted waterways. A new exhibit at the museum of the Science History Institute explores these complex legacies. Bold: Color From Test Tube To Textile takes visitors on a colorful 150-year journey through the history of synthetic dyes, examining the people and places who’ve shaped our modern understanding of color—from the laboratory to the factory floor, from the runway to retail, and beyond.

Effect of occupational exposure to vat-textile dyes on follicular and luteal hormones in female dye workers in Abeokuta, Nigeria.

Some synthetic dyes used mainly in textile industries have been associated with endocrine disruption, resulting in infertility, among other disorders. It is unknown if occupational exposure to Vat textile dyes among premenopausal dyers alters hormonal levels. We aimed at determining the probable effects of occupational exposure to Vat dyes on reproductive hormones of female textile dyers in the follicular and luteal phases while relating this to age categories and duration of exposure. Thirty-three premenopausal Vat textile dyers at "Itoku", Abeokuta, Nigeria, among a population of about 80 female dyers were age and sex-matched with 55 non-exposed (control) female participants. Using semi-structured questionnaires, socio-demographic, occupational details and the LMP of participants were obtained. Serum samples were collected in follicular and luteal phases and assayed for female sex hormones using Enzyme Immunoassay. Mann-Whitney U and Z- statistic were used for comparison of the two groups. P-value < 0.05 was considered to be significant. In the follicular phase, the result showed a lower mean FSH ranking (in age category ≤20 years) and higher (p<0.05) Estradiol ranking (in age category 31-40 years) in the exposed than the unexposed. Mean ranks of Progesterone and Estradiol in the luteal phase (age category 31-40 years) were higher (p<0.05) in the exposed, while Estradiol (age category ≥41years) ranked lower (p<0.05). Prolactin demonstrated a significant inverse relationship with the duration of exposure. Occupational exposure to Vat dye among female dyers in Abeokuta is associated with some sex hormone disruption which appears to be age and duration of exposure-related.

Carbon Dots an Integrative Nanostructure for Fluorescent Bio-imaging, Targeted Delivery of Medication and Phototherapy in Malignancy: A Review

Background: Silent onset and metastasis in tissues make cancer the most devastating illness globally. Monitoring the growth of the tumour and delivering drugs to specific tissues are some of the major issues associated with treatment. However, with an improved understanding of tumour microenvironments and advancements in nanocarriers of drugs, novel nano-targeting pathways that can be utilised by nanocarriers have been developed. Carbon Dots, with their tiny size and outstanding physicochemical features, are an emerging category of carbon nanostructures that have attracted a lot of curiosity. Objective: Multitudinous attempts and extensive studies have been undertaken by many researchers regarding the synthesis of Carbon Dots and their applications in various fields. These studies have explained that the synthesised Carbon Dots have versatile surface functionalities, high luminescence, and excellent biocompatibility. This article focuses on recent developments in synthesis approaches, carbon precursors used, and applications of Carbon Dots, specifically within the biomedical field, with a particular focus on cancer. Results: Carbon dots synthesised from a variety of precursors can act as prominent candidates for bioimaging and drug carriers and are used in cancer phototherapy. In this article, Carbon Dots are summarised based on their bright luminescent properties, distinct structure, drug loading capacity, and near-infrared (NIR) emission. Conclusion: Carbon dots, employed as tumour theranostics, can serve as an alternative to synthetic fluorescent dyes. They fulfil the role of bioimaging agents and facilitate the precise delivery of drugs to cancer cells. Additionally, they exhibit excellence as phototherapeutic agents, featuring high nearinfrared (NIR) emission and minimal side effects.

Syzygium cumini-mediated synthesis of rGO/Ag-Au nanostructures: Efficient catalysts for rapid degradation of organic dyes

BackgroundThe increasing human health risk caused by contamination of water by both natural and synthetic dye pollutants has become a crucial issue and poses an immense urge to find a sustainable approach for the removal of dye contaminants from wastewater. Photocatalysis performed in the presence of nanomaterials holds huge promise as an efficient and environmentally safe oxidation technology for organic dye removal from waste water. MethodsOur preparation methodology utilizes the extract derived from the endocarp of Syzygium cumini (SC) effects for concurrent reduction of GO and metal ions to form rGO/Ag-Au. The prepared rGO/Ag-Au nanostructures effectively breakdown organic dye pollutants like methylene blue (MB) and methyl orange (MO) dyes. Significant findingsA robust interaction between the rGO matrix and the Ag-Au nanoparticles was established by structural characterization, while morphological investigation displayed the nanoscale Ag-Au particles uniformly coated over the rGO sheet surface. The catalytic efficiency of the rGO/Ag-Au nanocomposite toward methylene blue (MB) and methyl orange (MO) chromophores decomposition was assessed with the aid of sodium borohydride (NaBH4). The decoration of well-spaced Ag-Au nanoparticles over the rGO sheet created firm catalytic active sites in the rGO/Ag-Au composite. With the improved catalytic active surface, the MB/MO dye was completely removed in a very short time of 2.5 to 5 min. The rGO/Ag-Au composite exhibited exceptional catalytic prowess in the disintegration of both dyes, leading to complete degradation. The remarkable efficacy in the dye degradation process can be attributed to the predominance of both electrostatic as well as π-π interactions between the nanocomposite and the dyes. As a result, the current study has developed an easy-to-use and green method for creating rGO/Ag-Au composites, offering a workable way to dispose of hazardous organic dyes in an affordable and efficient way.

Extraction of natural dyes from tarum leaves (Indigofera Tinctoria L.) using the Ultrasound-Assisted Extraction (UAE) method

The rapid development of the textile industry has led to increased use of synthetic dyes. Although synthetic dyes are more practical and economical, their use can have adverse effects on health and the environment. Natural dyes are utilized as alternatives with indigo leaves (Indigofera tinctoria L.) being one source known for producing a blue color. However, the commonly used extraction methods require long extraction times and significant solvent consumption. Given the limitations of current methods, innovation is needed for an efficient extraction method that produces safe and environmentally friendly natural dyes, one of which is ultrasound-assisted extraction (UAE). Therefore, this study aims to determine the extraction process of indigo leaves using UAE method, then identify the parameters influencing the extraction process using the UAE, determine the extraction yield using UAE, assess the dyeing results of the extracted dye from indigo leaves on cotton fabric, and compare the extraction results of indigo dye through the UAE method with the addition of CaO and NaOH solutions. The results of this study indicate that the natural dye from Indigofera tinctoria obtained the best conditions at extraction time of 90 min, feed-to-solvent ratio of 0.05 g/ml, and CaO-to-solvent ratio of 0.005 g/ml. Furthermore, the addition of CaO solution obtained the highest yield at 4.25 %, while the addition of NaOH solution resulted in 4.8 %. Additionally, the analysis and test results of the application of natural dye from Indigofera tinctoria on cotton fabric revealed a darker color with the addition of NaOH solution compared to the addition of CaO solution.

Comparing Color Strength Results through Analysis of Rinse Water between Wool Dyed with Onion Skins and Mordants and Synthetic Dye

The textile industry is one of the biggest global polluters releasing chemicals into the air, land, and water. The majority of these emissions are due to the chemicals that enter the water stream from the textile dyeing process. While synthetic dye effluents are very hard to remove from the wastewater, natural dyes have a very minimal effect on the environment due to their biodegradability. One major issue that prevents the textile industry from using natural dyes is the differences in colorfastness between the synthetic dyes and natural dyes. Because of this, this study will evaluate if the use of a mordant before fiber dyeing could increase the colorfastness of a natural dye so that the use of natural dyes can be increased in the textile industry. Harvesting a dye from yellow onion skins has proved to be an attractive dye product not only due to its color performance but since it is a natural waste product, not interfering in the food supply chain. Dye from onion skins was compared to a synthetic dye counterpart, Rit brand dye. One wool sample was dyed with Rit, and three others with the onion dye without a mordant, and with lemon juice or iron ferrous sulfate as mordants. These samples were then washed until the rinse water became clear. The rinse water was then evaluated with a UV-visible spectrophotometer. The KubelkaMunk theory was used to solve for color strength of the rinse water or how much dye bled from the wool during washing. In conclusion the Rit dye and the onion dye with the lemon mordant performed better than the onion dyes without a mordant and with an iron mordant.

Modern ecofriendly approach for extraction of luteolin natural dye from weld for silk fabric and wool yarn dyeing

The increasing apprehension regarding the ecological effects of synthetic dyes has prompted a transition towards sustainable and environmentally friendly substitutes in the textile sector. This research examines the eco-friendly use of a natural pigment obtained from the weld flower for dyeing of silk fabric and wool yarn. The study investigates the use of microwave-assisted extraction to acquire the luteolin based pigment found in the weld flower. An assessment is conducted to evaluate the effectiveness of microwave radiation in improving the extraction process, emphasizing its capacity to accelerate and enhance the production of the natural colorant. Moreover, the process of optimizing dyeing conditions is carried out utilizing a response surface approach, with a specific focus on parameters including temperature, time, pH, and salt content. The study also investigates the influence of mordants, such as iron salt, and aluminum salt, on improving color fastness and attaining bright and enduring hues. The study expands its research to examine the impacts of plant-based extracts, such as madder root, and oak, as bio-mordants for producing a wide array of colors. The study additionally highlights the favorable influence on color fastness, exhibiting significant enhancements in light fastness, wash fastness, and rubbing fastness for both silk and wool. The measurable results validate the effectiveness of the suggested environmentally friendly dyeing techniques, provide numerical evidence of their suitability for sustainable textile manufacturing.

Indigo dyes: Toxicity, teratogenicity, and genotoxicity studies in zebrafish embryos

Wastewater released by textile dyeing industries is a major source of pollution. Untreated wastewater released from indigo dyeing operations affects aquatic ecosystems and threatens their biodiversity. We have assessed the toxicity of natural and synthetic indigo dye in zebrafish embryos, using the endpoints of teratogenicity, genotoxicity, and histopathology. The zebrafish embryo toxicity test (ZFET) was conducted, exposing embryos to ten concentrations of natural and synthetic indigo dyes; the 96-hour LC50 values were approximately 350 and 300 mg/L, respectively. Both dyes were teratogenic, causing egg coagulation, tail detachment, yolk sac edema, pericardial edema, and tail bend, with no significant difference in effects between the natural and synthetic dyes. Both dyes were genotoxic (using comet assay for DNA damage). Real-time RT-PCR studies showed upregulation of the DNA-repair genes FEN1 and ERCC1. Severe histological changes were seen in zebrafish larvae following exposure to the dyes. Our results show that indigo dyes may be teratogenic and genotoxic to aquatic organisms, underscoring the need for development of sustainable practices and policies for mitigating the environmental impacts of textile dyeing.

Comparison of electrochemical advanced oxidation processes for the treatment of complex synthetic dye mixtures

Many industries use complex synthetic organic dye mixtures in their dyeing processes, producing wastewater effluents with complex dye mixtures. In this study, electrochemical advanced oxidation processes like electrochemical oxidation (ECO), ECO with electrogenerated H2O2 (ECO-H2O2), electro-Fenton (EF), and photo electro-Fenton (PEF) with UVC irradiation were compared to discolor and mineralize a mixture of Methyl Orange, Methyl Red, and Toluidine Blue O with a boron-doped diamond anode and a gas-diffusion cathode. While ECO and ECO-H2O2 required long times to achieve a complete discoloration, the dyes were quickly degraded by EF and PEF due to the oxidation with ∙OH formed from Fenton’s reaction. Almost complete mineralization was rapidly achieved by PEF for a solution with 424 mg O2 L−1 of chemical oxygen demand (COD) at a current density of 66.6 mA cm−2 due to the synergistic action of the UVC irradiation. Additionally, the treated effluent was evaluated using the DFZ (Deutsche Farb Zah) parameter for water condition, offering a new perspective and distinguishing this work from previous studies focused on electrified technologies for dye removal. The same behavior has been found for the mixture of such dyes in an industrial effluent upon PEF treatment, even showing faster discoloration and COD reduction as result of the additional removal with active chlorine formed from Cl− oxidation. Ion-exclusion HPLC analysis of the treated synthetic effluent revealed the formation of final carboxylic acids like malic, acetic, oxalic, and formic. Released nitrate, ammonia, and nitrite were detected as nitrogenated by-products from the initial N of the dyes.

Valorization of sugarcane bagasse for high-yield production of laccase through Aspergillus terreus for effective azo dye decolourization

Synthetic dyes such as azo dyes are significant pollutants in the wastewater released from various textile industries. The low biodegradability and production from synthetic sources with high shelf life make azo dyes a challenging material for degradation. This study used chemically mutated Aspergillus terrus in the laccase production under solid-state fermentation using sugarcane bagasse. Initially, the wild-type strain produced a laccase activity of 4.12 U/mL. Later, the alkaline pretreatment of sugarcane bagasse showed a significant increase in laccase activity by 38.9%. Further, random mutagenesis treatment with 100 mM EMS generated a hyper laccase-producing strain with a 2.3-fold increment in laccase activity compared to the wild-type strain. The enzyme displayed optimal activity at pH 6.5 and 35 °C. The metal ions such as Fe3+ (29.4 U/mL), Fe2+ (20.8 U/mL) and Cu2+ (18.05 U/mL) showed positive effects on laccase activity. The crude laccase was used to bioremediate Congo red, a prominent azo dye used in textile and pharmaceutical industries. The preliminary studies with a crude enzyme displayed 68.86% dye decolourization after 24 h of incubation. Additionally, with Taguchi orthogonal array optimization experiments, the maximal dye decolorization of 78.24% was achieved by maintaining crude enzyme concentration (20 U), dye concentration (25 mg/L) and pH 4.5.

Exploring indigenous fungal isolates for efficient dye degradation: A comprehensive study on sustainable bioremediation in the total environment

Synthetic dyes used in textile industries are hazardous and toxic to the environment, as some of the dyes used in these industries are non-biodegradable. Sustainable technologies using microbes are an eco-friendly and economical approach. Fungal decolorization processes are gaining much importance as biomass absorbs enzymes used in biodegradation. In the current study, six samples of dye wastewater were collected from different industries in the Faisalabad industrial area in Pakistan. The physiological characteristics of these samples were analyzed, and various parameters, including pH, temperature, BOD, COD, and electric conductivity, were investigated. Among six different (sample A-F) wastewater samples, the maximum reduction in BOD was observed in sample E, i.e.,1.3.In contrast, the maximum reduction in COD of sample C, i.e., 30, was observed. These samples' hydrogen ion concentration (pH) was mainly in an alkaline ratio, and a maximum electric conductivity of 8810 µS/cm of sample A was observed. In contrast, a minimum sample E (540 mg/L) was observed. Three indigenous fungal strains were screened and purified from dye wastewater for detoxification of dyes and were identified morphologically and on a molecular basis as Aspergillus iranicus, Penicillium crustosum, and Aspergillus terreus. A comparative analysis of two methods, the tube overlay method and the liquid medium method, were conducted to biodetoxification synthetic dyes, including malachite green, methylene blue, and nigrosine. Spectrophotometric analysis showed that indigenous fungal strains, i.e., Penicillium crustosum decolorizing methylene blue at about 93%, followed by Aspergillus iranicus decolorizing malachite green at about 80% and Aspergillus terreus decolorizing about 90% of malachite green have good potential for degradation of dyes. These strains can be a potential source for treating textile dye effluent.

An Introduction and Recent Advances in the Analytical Study of Early Synthetic Dyes and Organic Pigments in Cultural Heritage

This article reviews the research recently undertaken to characterise and identify early synthetic dyes (ESDs) and synthetic organic pigments (SOPs) as well as study their degradation pathways with a focus on cultural heritage applications. Since the invention of the first fully synthetic dye in 1856, these materials have been used in a variety of historic objects and artworks, such as textiles, furniture, prints, paintings, drawings, etc. The synthesis of new dyes and their implementation into pigment formulations were rapid phenomena, so that by the beginning of the 20th century, thousands of new molecules were patented and commercialised. This review will focus on these early formulations synthesised up to approximately 1914 and the outbreak of World War I. ESDs and SOPs represent a challenge from an analytical point of view. Molecular databases are fundamental for the unequivocal identification of these compounds, but reference materials are not always readily available. A combination of analytical techniques is often needed for characterisation, especially in the case of SOPs, which have both organic and inorganic components. Furthermore, the degradation of these molecules can jeopardise their detection in historic objects that have been exposed to light, humidity and temperature fluctuations. Nevertheless, ESDs and SOPs are important research tools. As the dates of their first synthesis are often known with precision, based on patent information, their detection can be used to refine the production date of objects. Additionally, their trade from Europe to the world and their adoption in artistic practices around the globe is an active area of research.

Statistical Optimization and Kinetic Studies of Water Hyacinth Stem–Based Activated Carbon Adsorbent for Synthetic Textile Dye Effluent Treatment

Statistical Optimization and Kinetic Studies of Water Hyacinth Stem–Based Activated Carbon Adsorbent for Synthetic Textile Dye Effluent Treatment

Rhodamine B Hazardous Dye Removal via Adsorption Using Hg(II) Coordination Polymer

Herein, we have reported the Hg(II) coordination polymer ,(Hg-CP), formulated {[Hg(L)](Cl2)](CH3CN)2}n, behaved as adsorbent against Rhodamine B dye stuff. UV-Vis absorption spectroscopy was used to conduct dye adsorption investigations on coordination polymers. Adsorption experiments were carried out in acidic (pH=3) and neutral (pH=6) media and the results showed that the compound removed the cationic Rhodamine B from water. In acidic media, the adsorption capacity of the Hg-CP was more than neutral media. Also, Hg-CP could selectively adsorb Rhodamine B dye from the Rhodamine B/Methyl orange dye mixture. The colour of the Hg-CP was white before adsorption, whereas it changed after adsorption as Rhodamine B adhered to the surface of Hg-CP.

Tapered optical fiber sensor coated with carbon nanotubes containing functional groups or Fe nanoparticles for sensing applications

Anthraquinone dyes are the second largest group of synthetic dyes that are widely used for dyeing textiles. As an anthraquinone dye, Alizarin Red S (ARS) has been widely used in the textile industry; however, it is extremely resistant to standard degradation due to its structural peculiarities and it can cause a serious threat to aquatic ecosystems and human health. Previous studies on theoretical calculations of single-wall carbon nanotubes (SWCNTs) and multi-wall carbon nanotubes (MWCNTs) demonstrated that SWCNTs and MWCNTs can serve as adsorbents, with their highly active sites and large specific surface area, and they exhibit great performance. In the present work, the detection of ARS by the SMF28e single-mode fiber optic-based sensor was investigated. For detection of ARS, multiwall carbon nanotubes with -COOH and -OH functional groups and Fe nanoparticles were applied on the optical fiber. The effects of contact time, adsorbent dose, pH and temperature on the adsorption were studied. The study evaluated the feasibility of detecting and removing ARS from aqueous solutions using MWCNTs with the -COOH and -OH functional groups and Fe nanoparticles.

Adsorption and photocatalytic degradation activities of a hybrid magnetic mesoporous composite of α-Fe2O3 nanoparticles embedded with sheets-like MgO

Crystal violet (CV), identified as a potential carcinogen, is a synthetic dye prevalent in wastewater from textile and paint industries. Therefore, the current study demonstrates that the hybrid composite of mesoporous magnetic α-Fe2O3 nanoparticles @ sheet-like MgO (Fe2O3@MgO) can be employed as a potential effective sorbent and photocatalyst for CV-removal from polluted water. A comparative study was systematically performed on the CV-removal using MgO and Fe2O3@MgO composite. The physicochemical, textural, and structural properties, morphological features, and elemental composition of mesoporous Fe2O3@MgO composite were intensively investigated. Batch trials were performed to optimize the sorption conditions. The highest CV-uptake efficiency was detected at pH 9 within the adsorption equilibrium time of about 30 min, where the maximum capacity of Fe2O3@MgO was 50.8 mg/g. Under UV irradiation, the Fe2O3@MgO photocatalyst exhibited a high efficiency and fast response toward CV-removal. The mechanism of CV removal was researched through zeta potential (ZP), bandgap, and density functional theory (DFT) calculations. The outcome demonstrated that mesoporous Fe2O3@MgO sorbent/photocatalyst could be recycled and reused ten times, making it a cost-effective solution for removing CV-dye from wastewater. This manuscript suggested that mesoporous Fe2O3@MgO composite is an efficient adsorbent/photocatalyst for fast, affordable, and efficient decontamination of CV-dye from wastewater.

The Application of Chitosan-Based Adsorbents for the Removal of Hazardous Pollutants from Aqueous Solutions—A Review

The development of simple, effective, economical, and environmentally friendly methods for removing hazardous substances of anthropogenic origin from aquatic systems is currently one of the greatest challenges, among others, due to the variety of pollutants and the transformations they may undergo in the environment. In recent years, there has been an increased interest in adsorption methods based on the use of natural polymers, including non-toxic chitosan (CS), which is characterized by good coating properties, biocompatibility, and biodegradability. This review concerns the latest developments (since 2019) in the application of novel chitosan-based materials for the removal of hazardous substances (e.g., metal and metalloid ions, synthetic dyes, pharmaceuticals) from aqueous solutions, with particular emphasis on their most important advantages and limitations, as well as their potential impact on sustainability.

Peroxidase like activity of Prussian blue nanoparticles and visible light mediated catalytic degradation of methylene blue dye

The environmental impact of dyes, particularly those utilized in the pharmaceutical and textile industries, has been a growing concern due to their persistence and potential harm to ecosystems. Methylene Blue (MB) dye is one of the commonly used synthetic dyes known for its adverse effects on the environment. Thus a promising catalyst is required for the effective degradation of MB dye. To effectively degrade MB, we have synthesized Prussian blue nanoparticles (PBNPs) in this work using the co-precipitation technique. These nanoparticles showed the peroxidase like behavior by degrading hydrogen peroxide and generating ROS (reactive oxygen species) under visible light exposure, which oxidized MB leads to its degradation. This degradation process was investigated under various experimental conditions, including pH, catalyst dosage, and peroxide concentration. The results demonstrated that PBNPs exhibited remarkable catalytic activity and completely degrade the MB within 50 min under visible light. The degradation efficiency was found to be pH-dependent and optimum efficiency was found in pH range from 5 to 7. The kinetic studies were shown that this MB degradation process follows the first order kinetic models with the rate constant value 0.038 s−1, suggesting that the degradation process follows Fenton mechanism. The recyclability and stability of the PBNPs as a catalyst were also assessed, which showed that it can be used up to four cycles, demonstrating their potential for practical applications in dye wastewater treatment.

Characterization of an abundant illitic clay from the Safi region in Morocco and its exploitation in the treatment of industrial effluents loaded with synthetic dyes

The objective of this work is to valorize abundant illitic clay from Morocco in the treatment of industrial effluents likely to be loaded with synthetic dyes such as the textile, stationery, cosmetic, food, and also pharmaceutical industries. The penitential adsorbing of two dyes: methylene blue (BM) and malachite green (GM) was studied on this clay. Firstly, this clay was characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) analysis and X-ray fluorescence analysis. And on the other hand, Effect of different parameters on adsorption kinetics has been studied, such as contact time, initial dye concentration, pH, salinity and temperature. Adsorption tests results showed that equilibrium was established after 30 min and the adsorption of the two dyes depends on the initial dye concentration and the pH. The results showed was the adsorption of the two dyes can be described by pseudo-second-order kinetics. The results indicate also that the process is a spontaneous endothermic physisorption characterized by disorder of the environment. This study shows that this raw, abundant and low-cost natural illitic clay can be valorized and exploited to treat effluents loaded with synthetic dyes.

Влияние ингибиторов фенолоксидаз на эффективность деколоризации малахитового зеленого бактериями рода Azo spirillum

Synthetic dyes are widely used in various branches of light industry. Due to the insufficient efficiency of industrial painting processes, a large percentage of dyes end up in the wastewater of enterprises in an unmodified form, which creates a huge risk of environmental pollution with these compounds. Triphenylmethane dyes, in particular malachite green, are toxic, allergenic and carcinogenic compounds. To date, biodegradability of triphenylmethane dyes has been shown for some bacteria and fungi producing phenol oxidase complex enzymes, including soil associative bacteria of the genus Azospirillum. Many factors are capable of inducing and inhibiting the biodegradation efficiency, in particular the enzymatic systems that are involved in bleaching processes. In the present work we studied the effects of typical deactivating agents of phenol oxidases, such as H2O2, EDTA, SDS-Na, β-mercaptoethanol, dithiothreitol, Tween, and sodium azide, on the azospirilla’s phenol oxidases activity and the ability to decolorize malachite green. It was found that Tween and sodium azide do not have an inhibitory effect on azospirillum enzymes and exhibit a total stabilizing effect on the entire complex. An inhibitory effect from 60 to 100% was noted for laccase and Mn-peroxidase activity under the action of β-mercaptoethanol, dithiothreitol and EDTA, which is directly proportional to the decolorization rate of malachite green. Compared with the latest issues on classical phenol-oxidizing enzymes, our data revealed non-typical properties of the phenol oxidase complex enzymes of azospirillum.