scholarly journals Structure-Based Long-Term Biodegradation of the Azo Dye: Insights from the Bacterial Community Succession and Efficiency Comparison

Water ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 3017
Author(s):  
Chao Zhu ◽  
Zarak Mahmood ◽  
Muhammad Saboor Siddique ◽  
Heyou Wang ◽  
He Anqi ◽  
...  
Keyword(s):  
Bacterial Community ◽  
Azo Dyes ◽  
Azo Dye ◽  
Community Dynamics ◽  
Molecular Structures ◽  
Methyl Red ◽  
Biological Degradation ◽  
Chemical Structures ◽  
Microbial Community Dynamics ◽  
Efficiency Comparison

In this study, microbial community dynamics were explored during biological degradation of azo dyes with different chemical structures. The effect of the different molecular structures of the azo dyes was also assessed against the simultaneous removal of color and the bacterial community. Winogradsky columns were inoculated with dewatered sludge and separately fed with six different azo dyes to conduct the sludge acclimatization process, and nine bacterial decolorizing strains were isolated and identified. The decolorization and biodegradation performances of the acclimated system and isolated strains were also determined. Results showed that the bacterial isolates involved in decolorization and the degradation of the azo dyes were mainly associated with the azo dye structure. After 24 h acclimatization at room temperature without specific illumination, immediate decolorization of methyl red (89%) and methyl orange (78%) was observed, due to their simple structure compared to tartrazine (73%). However, after 8 days of acclimatization, methyl red was easily decolorized up to 99%, and about 87% decolorization was observed for orange G (87%), due to its complex chemical structure. Higher degrees of degradation and decolorization were achieved with Pseudomonas geniculate strain Ka38 (Proteobacteria), Bacillus cereus strain 1FFF (Firmicutes) and Klebsiella variicola strain RVEV3 (Proteobacteria) with continuous shaking at 30 °C. The azo dyes with benzene rings were found to be easier to decolorize and degrade with similar microbial communities. Moreover, it seems that the chemical structures of the azo dyes, in a sense, drove the divergent succession of the bacterial community while reducing the diversity. This study gives a deep insight into the feasible structure-based artificial manipulation of bacterial communities and offers theoretical guidance for decolorizing azo dyes with mixed bacteria cultures.

Effect of Photo-Isomerization of Azo Dyes on the Photonic Bandgap in Chiral Nematics

2011 ◽  
Vol 181-182 ◽  
pp. 257-260
Author(s):  
David Statman ◽  
Andrew Jockers ◽  
Daniel Brennan
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystals ◽  
Azo Dyes ◽  
Azo Dye ◽  
Photonic Bandgap ◽  
Methyl Red ◽  
Central Wavelength ◽  
Chiral Nematic ◽  
Anchoring Energy ◽  
Pitch Length

Chiral nematic liquid crystals prepared with Grandjean texture demonstrate a photonic bandgap whose central wavelength is proportional to the pitch length, P, of the liquid crystal and whose width is given by (ne – no)P. We show that methyl red doped chiral nematics undergo a shift in the photonic bandgap upon photo-isomerization. This shift is a result of (1) photo-induced change in anchoring energy on the nematic surface, and (2) change in the natural pitch length from the photo-isomerization of the azo dye.

scholarly journals Ecosystem Resilience and Limitations Revealed by Soil Bacterial Community Dynamics in a Bark Beetle-Impacted Forest

mBio ◽  
2017 ◽  
Vol 8 (6) ◽  
Author(s):  
Kristin M. Mikkelson ◽  
Brent M. Brouillard ◽  
Chelsea M. Bokman ◽  
Jonathan O. Sharp
Keyword(s):  
Water Quality ◽  
Bacterial Community ◽  
Tree Mortality ◽  
Community Dynamics ◽  
Watershed Scale ◽  
Microbial Community Dynamics ◽  
Local Soil ◽  
The World ◽  
Water Quality And Quantity ◽  
Insight Into

ABSTRACT Forested ecosystems throughout the world are experiencing increases in the incidence and magnitude of insect-induced tree mortality with large ecologic ramifications. Interestingly, correlations between water quality and the extent of tree mortality in Colorado montane ecosystems suggest compensatory effects from adjacent live vegetation that mute responses in less severely impacted forests. To this end, we investigated whether the composition of the soil bacterial community and associated functionality beneath beetle-killed lodgepole pine was influenced by the extent of surrounding tree mortality. The most pronounced changes were observed in the potentially active bacterial community, where alpha diversity increased in concert with surrounding tree mortality until mortality exceeded a tipping point of ~30 to 40%, after which diversity stabilized and decreased. Community structure also clustered in association with the extent of surrounding tree mortality with compositional trends best explained by differences in NH4 + concentrations and C/N ratios. C/N ratios, which were lower in soils under beetle-killed trees, further correlated with the relative abundance of putative nitrifiers and exoenzyme activity. Collectively, the response of soil microorganisms that drive heterotrophic respiration and decay supports observations of broader macroscale threshold effects on water quality in heavily infested forests and could be utilized as a predictive mechanism during analogous ecosystem disruptions. IMPORTANCE Forests around the world are succumbing to insect infestation with repercussions for local soil biogeochemistry and downstream water quality and quantity. This study utilized microbial community dynamics to address why we are observing watershed scale biogeochemical impacts from forest mortality in some impacted areas but not others. Through a unique “tree-centric” approach, we were able to delineate plots with various tree mortality levels within the same watershed to see if surviving surrounding vegetation altered microbial and biogeochemical responses. Our results suggest that forests with lower overall tree mortality levels are able to maintain “normal” ecosystem function, as the bacterial community appears resistant to tree death. However, surrounding tree mortality influences this mitigating effect with various linear and threshold responses whereupon the bacterial community and its function are altered. Our study lends insight into how microscale responses propagate upward into larger-scale observations, which may be useful for future predictions during analogous disruptions. IMPORTANCE Forests around the world are succumbing to insect infestation with repercussions for local soil biogeochemistry and downstream water quality and quantity. This study utilized microbial community dynamics to address why we are observing watershed scale biogeochemical impacts from forest mortality in some impacted areas but not others. Through a unique “tree-centric” approach, we were able to delineate plots with various tree mortality levels within the same watershed to see if surviving surrounding vegetation altered microbial and biogeochemical responses. Our results suggest that forests with lower overall tree mortality levels are able to maintain “normal” ecosystem function, as the bacterial community appears resistant to tree death. However, surrounding tree mortality influences this mitigating effect with various linear and threshold responses whereupon the bacterial community and its function are altered. Our study lends insight into how microscale responses propagate upward into larger-scale observations, which may be useful for future predictions during analogous disruptions.

scholarly journals Phylogenetically diverse bacteria isolated from tattoo inks, an azo dye-rich environment, decoloize a wide range of azo dyes

2021 ◽  
Author(s):  
Seong Won Nho ◽  
Xue Wen Cui ◽  
Ohgew Kweon ◽  
Jinshan Jin ◽  
Huizhong Chen ◽  
...  
Keyword(s):  
High Throughput ◽  
Azo Dyes ◽  
Azo Dye ◽  
Dye Degradation ◽  
Methyl Red ◽  
Diverse Range ◽  
Optical Absorbance ◽  
Wide Range ◽  
Systematic Understanding ◽  
Tattoo Inks

Abstract Purpose: There has been an interest in the microbial azo dye degradation as an optional method for the treatment of azo dye-containing wastes. Tattoo ink is an extremely unique azo dye-rich environment, which never been explored in terms of microorganisms capable of degrading azo dyes. Previously, we isolated 81 phylogenetically diverse bacteria, belonging to 20 genera and 49 species, contaminated in tattoo inks. In this study, we investigated if these bacteria, which can survive in the azo dye-rich environment, have an ability to degrade azo dyes. Methods: We conducted a two-step azo dye degradation (or decolorization) assay. In step 1, a high-throughput degradability assay was done for 81 bacterial isolates using Methyl Red and Oragne II. In step 2, a further degradation assay was done for 10 selected bacteria with a representative of 11 azo dyes, including 3 commercial tattoo ink azo dyes. Degradation of azo dyes were calculated from measuring optical absorbance of souble dyes at specific wavelenths. Results: The initial high-throughput azo dye assay (step 1) showed that 79 isolates had a complete or partial degradation of azo dyes; >90% of Methyl Red and Orange II were degraded within 24 h, by 74 and 20 isolates, respectively. A further evaluation of azo dye degradability for 10 selected isolates in step 2 showed that the isolates, belonging to Bacillus , Brevibacillus , Paenibacillus , and Pseudomonas , exhibited an excellent decolorization ability for a wide range of azo dyes. Conclusions: This study showed that phylogenetically diverse bacteria, isolated from azo dye-rich tattoo inks, is able to degrade a diverse range of azo dyes, including 3 azo dyes used in commercial tattoo inks. Some of the strains would be good candidates for future studies to provide a systematic understanding of azo dye degradation mechanisms

Decolorization of Azo Dyes by a New Strain CD-2 Isolated from the Textile Dye Contaminated Water

2011 ◽  
Vol 183-185 ◽  
pp. 381-386 ◽  
Author(s):  
Dai Zong Cui ◽  
Min Zhao ◽  
Guo Fang Li ◽  
Xiao Xu Gu ◽  
Guang Ying Hui Du ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Azo Dyes ◽  
Azo Dye ◽  
Dye Removal ◽  
Contaminated Water ◽  
Textile Dye ◽  
Methyl Red ◽  
E Coli ◽  
Eriochrome Black T ◽  
Ph Range

In this study, a new strain was isolated by us based on its efficiency to decolorize azo dyes. Identification of this isolate by 16S rDNA technique revealed that the strain belonged to Escherichia, and clustered within Escherichia coli. According to this, we renamed our strain as E. coli CD-2. The strain CD-2 could decolorize azo dyes effectively under aerobic conditions. CD-2 exhibited good decolorization ability in the pH range from 3 to 11, temperature from 30°C to 42°C and salinity from 1% to 4%. CD-2 could decolorized different azo dyes (methyl red, Congo red, eriochrome black T and eriochrome red B) within 16h, and the decolorizing rate were 97.15%, 86.03%, 56.92% and 81.14%, respectively. This degradation potential increased the applicability of this strain for the azo dye removal.

Microbial community dynamics in SBR for azo dyes treatment by PCR–DGGE technique

2008 ◽  
Vol 136 ◽  
pp. S609
Author(s):  
Liang Tan ◽  
Yuanyuan Qu ◽  
Jiti Zhou ◽  
Zhiyong Song ◽  
Ang Li ◽  
...  
Keyword(s):  
Microbial Community ◽  
Azo Dyes ◽  
Community Dynamics ◽  
Microbial Community Dynamics

Influence of dye type and salinity on aerobic decolorization of azo dyes by microbial consortium and the community dynamics

2012 ◽  
Vol 65 (8) ◽  
pp. 1375-1382 ◽  
Author(s):  
Liang Tan ◽  
Shuxiang Ning ◽  
Ying Wang ◽  
Xiangyu Cao
Keyword(s):  
Microbial Community ◽  
Azo Dyes ◽  
Kinetic Data ◽  
Community Dynamics ◽  
Dye Removal ◽  
Microbial Consortium ◽  
Zero Order ◽  
Chemical Structures ◽  
Zero Order Kinetics ◽  
Microbial Community Structures

In this research, aerobic decolorization of different azo dyes by a microbial community was studied. The results showed that more than 80% of four azo dyes (100 mg/L) could be aerobically decolorized by the microbial consortium, however, the time needed was obviously different. Kinetic data indicated that the processes were well described by zero-order kinetics, and the chemical structures of dyes had obvious influence on decolorization rates. On the other hand, effects of salinity on decolorization were also investigated. There was still 40% dye removal for Acid Brilliant Red GR when the salinity increased to 250 g/L. And the microbial community structures with different salinity were detected by PCR-DGGE. It was shown that the same two bacteria were dominant in all decolorization systems, and some typical halophilic microorganisms were found under higher-salt conditions.

scholarly journals Phylogenetically diverse bacteria isolated from tattoo inks, an azo dye-rich environment, decolorize a wide range of azo dyes

2021 ◽  
Vol 71 (1) ◽  
Author(s):  
Seong Won Nho ◽  
Xuewen Cui ◽  
Ohgew Kweon ◽  
Jinshan Jin ◽  
Huizhong Chen ◽  
...  
Keyword(s):  
High Throughput ◽  
Azo Dyes ◽  
Azo Dye ◽  
Dye Degradation ◽  
Orange Ii ◽  
Methyl Red ◽  
Diverse Range ◽  
Optical Absorbance ◽  
Wide Range ◽  
Tattoo Inks

Abstract Purpose There has been an interest in the microbial azo dye degradation as an optional method for the treatment of azo dye-containing wastes. Tattoo ink is an extremely unique azo dye-rich environment, which have never been explored in terms of microorganisms capable of degrading azo dyes. Previously, we isolated 81 phylogenetically diverse bacteria, belonging to 18 genera and 52 species, contaminated in tattoo inks. In this study, we investigated if these bacteria, which can survive in the azo dye-rich environment, have an ability to degrade azo dyes. Methods We conducted a two-step azo dye degradation (or decolorization) assay. In step 1, a high-throughput degradability assay was done for 79 bacterial isolates using Methyl Red and Orange II. In step 2, a further degradation assay was done for 10 selected bacteria with a representative of 11 azo dyes, including 3 commercial tattoo ink azo dyes. Degradation of azo dyes were calculated from measuring optical absorbance of soluble dyes at specific wavelengths. Results The initial high-throughput azo dye assay (step 1) showed that 79 isolates had a complete or partial degradation of azo dyes; > 90% of Methyl Red and Orange II were degraded within 24 h, by 74 and 20 isolates, respectively. A further evaluation of azo dye degradability for 10 selected isolates in step 2 showed that the isolates, belonging to Bacillus, Brevibacillus, Paenibacillus, and Pseudomonas, exhibited an excellent decolorization ability for a wide range of azo dyes. Conclusions This study showed that phylogenetically diverse bacteria, isolated from azo dye-rich tattoo inks, is able to degrade a diverse range of azo dyes, including 3 azo dyes used in commercial tattoo inks. Some of the strains would be good candidates for future studies to provide a systematic understanding of azo dye degradation mechanisms.

Use of a sequencing batch biofilter for degradation of azo dyes (acids and bases)

2000 ◽  
Vol 42 (5-6) ◽  
pp. 329-336 ◽  
Author(s):  
M. Quezada ◽  
I. Linares ◽  
G. Buitrón
Keyword(s):  
Azo Dyes ◽  
Azo Dye ◽  
Degradation Rate ◽  
Removal Rate ◽  
Textile Effluent ◽  
Colour Removal ◽  
Substrate Degradation ◽  
Acids And Bases ◽  
Removal Efficiencies ◽  
Basic Red 46

The degradation of azo dyes in an aerobic biofilter operated in an SBR system was studied. The azo dyes studied were Acid Red 151 and a textile effluent containing basic dyes (Basic Blue 41, Basic Red 46 and 16 and Basic Yellow 28 and 19). In the case of Acid Red 151 a maximal substrate degradation rate of 288 mg AR 151/lliquid·d was obtained and degradation efficiencies were between 60 and 99%. Mineralization studies showed that 73% (as carbon) of the initial azo dye was transformed to CO2 by the consortia. The textile effluent was efficiently biodegraded by the reactor. A maximal removal rate of 2.3 kg COD/lliquid·d was obtained with removal efficiencies (as COD) varying from 76 to 97%. In all the cycles the system presented 80% of colour removal.

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