Article
Biotechnology & Applied Microbiology
Qingyun Zhang, Xuehui Xie, Dayong Xu, Ran Hong, Jiajia Wu, Xiancheng Zeng, Na Liu, Jianshe Liu
Summary: Fructose as a promising co-substrate was found to enhance the biodegradation and detoxification of refractory dye RB5 by a novel isolated Pseudomonas aeruginosa strain DDMZ1-2, leading to increased secretion and activity of extracellular azoreductase, production of more low molecular weight intermediates, and reduction of microbial toxicity and phytotoxicity in degradation metabolites.
ENVIRONMENTAL TECHNOLOGY & INNOVATION
(2021)
Article
Engineering, Environmental
Deepshikha Pandey, Achlesh Daverey, Kasturi Dutta, Kusum Arunachalam
Summary: Textile industries produce wastewater with harmful azo dyes that are known to be carcinogenic and mutagenic. This study evaluates the potential use of enzyme immobilized biochar for removing azo dyes from real and simulated textile effluents. The results show that the enzyme immobilized system can achieve high removal efficiency for individual azo dyes in the simulated effluent and for one dye peak in the real effluent. The presence of metabolite in the real effluent indicates the degradation of the dye. Therefore, enzyme immobilized biochar system can be used for simultaneous adsorption and degradation of toxic azo dyes from real effluents.
JOURNAL OF WATER PROCESS ENGINEERING
(2023)
Article
Engineering, Environmental
Hui Xu, Liang Zhang, Chunhong Yao, Bo Yang, Yan Zhou
Summary: This study developed a core-shell structured Fe@C composite to demonstrate its long-term feasibility for enhancing azo dye biodegradation, compared to a mixture of NZVI and carbon powder (Fe+C). The results showed that Fe@C had better performance, durability, and stability than Fe+C, possibly due to the carbon layer's ability to form a stable buffer to regulate NZVI dissolution. The microbial community analysis revealed that Fe@C promoted the growth of azo dye degraders, and metatranscriptomic analysis further revealed the substantial stimulation of genes involved in the extracellular degradation of azo dye by Fe@C. This study provides novel insights into the bioaugmentation of Fe@C for refractory wastewater treatment.
Article
Agricultural Engineering
Jiawei Fan, Wei Li, Bing Zhang, Wenxin Shi, Piet N. L. Lens
Summary: This study shows that the removal efficiency of azo dyes by AGS increases at low salinity levels, but the microbial cell viability of AGS is negatively affected at high salinity levels, leading to a decrease in removal and nutrient removal efficiencies. The removal of AO7 is achieved through adsorption and biodegradation.
BIORESOURCE TECHNOLOGY
(2022)
Article
Environmental Sciences
Ghulam Mustafa, Muhammad Tariq Zahid, Mayur Bharat Kurade, Swapnil Mahadeo Patil, Farah Rauf Shakoori, Zeeshan Shafiq, Sidra Ihsan, Yongtae Ahn, Azmat Ali Khan, Amel Gacem, Byong-hun Jeon
Summary: This study successfully overexpressed the AzK gene in Escherichia coli for the efficient degradation of Remazol Red-R and Acid-Blue 29 dyes. Optimal conditions were determined as 1.5% inoculum size, 0.5 mM IPTG concentration, and 6 hours incubation time. The crude extract achieved 76% and 74% decolorization of RRR and AB-29, while the purified enzyme achieved 94% and 93% decolorization within 0.3 hours. Kinetic analysis revealed the enzymatic characteristics and HPLC and GC-MS analyses confirmed the effective biotransformation of dyes into less toxic metabolites. This study highlights the potential of recombinant azoreductase for the degradation of textile azo dyes.
ENVIRONMENTAL POLLUTION
(2023)
Article
Materials Science, Multidisciplinary
Rong-ping Chen, Jia-li Cai, Qing Li, Lei Yu, Xin-yuan Wei, Cheng-hao Gan, Ru-xue Liu, Qiang Yong
Summary: The study prepared biodegradable RMs and investigated their effects on biological treatment of azo dyes; Induction of RMs accelerated extracellular electron transfer and enhanced dye decolorization efficiency; This research provides theoretical guidance for efficient biodegradation of azo dye wastewater using lignin resources.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2021)
Article
Environmental Sciences
Shellina Khan, Uma Bhardwaj, Hafiz M. N. Iqbal, Navneet Joshi
Summary: Current environmental research focuses on the sustainable use of mixed bacterial consortium for biodegradation of toxic compounds, specifically hazardous synthetic dyes. Various methods, including microbial treatments, are being explored for wastewater treatment to protect natural water bodies from pollution caused by textile effluents. Microbial consortia show efficient results in degrading toxic dyes and promoting plant growth, providing a non-toxic solution for environmental protection.
Review
Chemistry, Multidisciplinary
B. Senthil Rathi, P. Senthil Kumar
Summary: This article discusses the classification, source, and impact of AD in textile effluents. It introduces biodegradation methods such as bacteria, fungi, algae, and enzyme treatment, and also explores the recent advancements in AD removal through biodegradation.
CURRENT OPINION IN GREEN AND SUSTAINABLE CHEMISTRY
(2022)
Article
Microbiology
Hulin Qiu, Fengfei Shen, Aiguo Yin, Jiaxian Liu, Biyu Wu, Ying Li, Yunyi Xiao, Jinping Hai, Bo Xu
Summary: This study successfully decolorized azo dyes in high-salt industrial wastewater under high-salt and low oxygen conditions using extreme halophilic/halotolerant bacteria screened from the salt fields of Tibet. The degradation pathways were verified and the microflora showed strong degradative ability and tolerance to salt concentration changes.
FRONTIERS IN MICROBIOLOGY
(2022)
Article
Food Science & Technology
P. David Josephy, Emma Allen-Vercoe
Summary: Azo compounds are synthetic chemicals widely used as dyes and pharmaceuticals. They can be reduced in the gut by bacteria, leading to the formation of toxic aromatic amine metabolites. This review discusses the development and applications of azo compounds in industry and medicine, as well as the toxicology of azo compounds and their metabolites using specific examples. Knowledge gaps in this field are identified.
FOOD AND CHEMICAL TOXICOLOGY
(2023)
Article
Multidisciplinary Sciences
Isis Viana Mendes, Mariana Botelho Garcia, Ana Carolina Araujo Bitencourt, Renata Henrique Santana, Philippe de Castro Lins, Rafaella Silveira, Blake A. Simmons, John M. Gladden, Ricardo Henrique Kruger, Betania Ferraz Quirino
Summary: Natural selection was used to enrich microbial consortia capable of utilizing lignin as the sole carbon source, resulting in a decrease in bacterial richness and diversity after the enrichment protocol. The type of lignin used as a carbon source had a greater impact on differentiating the bacterial consortia than the variable temperature. Selected bacterial genera for lignin utilization included Altererythrobacter, Bacillus, Pseudomonas, and others.
Article
Environmental Sciences
Shantkriti Srinivasan, Paul Olusegun Bankole, Senthil Kumar Sadasivam
Summary: This study investigated the decolorization efficiency of selective reactive azo dyes by non-adapted Lysinibacillus sphaericus MTCC 9523 in optimized conditions, with visual color changes and spectroscopic analysis confirming decolorization. HPLC analysis showed differences in retention time between control and treated samples, supporting biodegradation, while GC-MS analysis revealed the chemical identities of metabolites and predicted the metabolic pathways of degradation for each dye. Overall, the use of adapted and non-adapted microbes is a promising, cost-effective and time-saving green strategy for the biodegradation of textile effluent containing azo dyes.
FRONTIERS IN ENVIRONMENTAL SCIENCE
(2022)
Article
Microbiology
Islam M. Kamal, Nourtan F. Abdeltawab, Yasser M. Ragab, Mohamed A. Farag, Mohammed A. Ramadan
Summary: The study screened cost-effective biodegraders for the recalcitrant diazo dye Direct Red 81 (DR81) using an enrichment technique, achieving significant decolorization in real wastewater. Azoreductase played a key role in DR81 decolorization, with metabolites found to be non-toxic.
Article
Chemistry, Multidisciplinary
Guoxun Zhu, Yan Lin, Wenxian Zhou, Huacan Song, Zhengquan Li
Summary: In this study, a combined experimental and DFT investigation was performed to study the UV-Vis spectra of o-methoxyaniline-terminated mono azo dyes. The excitation processes were determined using time-dependent DFT calculations and visualized through hole-electron analysis. Fragment-divided analysis was conducted to understand the contributions of different parts of the structures to the spectra. The effect of substituent electronegativity on electron densities and spectra was also investigated. Additionally, a linear model connecting the lambda(max) and W-1/2 to chemical shifts obtained from NMR spectroscopy was developed for the construction of a spectral library.
Article
Chemistry, Analytical
Tanmay Vyas, Manashjit Gogoi, Abhijeet Joshi
Summary: In this study, a pH-sensitive CQD thin film was developed for the detection of textile dye pollutants in water resources. The film exhibited fast and accurate detection of various acidic and basic dyes, with low detection limits.
