Figure 3
Bacterial growth and CSH of strain YL-JM2C during degradation of TCS (5 mg L −1 ). Values are means ± standard deviations of three replicates.
Source publication
Triclosan (TCS) is one of the most widespread emerging contaminants and has adverse impact on aquatic ecosystem, yet little is known about its complete biodegradation mechanism in bacteria. Sphingomonas sp, strain YL-JM2C, isolated from activated sludge of a wastewater treatment plant, was very effective on degrading TCS. Response surface methodolo...
Citations
... Specifically, Alkalilimnicola, Tissierella, Lascolabacillus, and Pusillimonas are known to play a crucial role in TCS degradation, as the degradation rate of TCS has shown a strong link with the relative abundance of these microorganisms (Zheng et al., 2020). Besides, previous studies have reported that Pseudomonas, Sphingomonas, and Novosphingobium in sewage sludge can also degrade TCS (Mulla et al., 2016;Thelusmond et al., 2019). Zheng et al. (2020) find that the relative abundance of Pseudomonas in 0th d, 2nd d (mesophilic phase), 7th d (thermophilic phase), and 17th d (cooling phase) is 0.1, 0.5, 2.2, and 0.4% (the ratios in the total microbial community), respectively, in the medium ventilation composting system with 13.9% oxygen content. ...
Triclosan (TCS) is an anti-microbial widely used in personal care and medical antibacterial products. Despite the widespread occurrence of TCS in municipal sewage sludge, understanding toward the fate of TCS within sewage treatment and environmental risks in the eventual land application is still limited. This review summarizes the TCS loads and transfer mechanisms in the sewage treatment process, sludge management process, land application, and its potential environmental impacts. TCS transfer from sewage to sludge mainly occurs in the primary sed-imentation process, representing 2.50 to 4.58 times more compared to the secondary sedi-mentation process. This transfer is facilitated through adsorption because of the presence of humic acid-like and protein-like substances in sludge. Both anaerobic digestion and aerobic compost-ing contribute to the degradation of TCS with aerobic composting being more effective, exhibiting TCS degradation rates 1.04-2.87 times higher than those observed in anaerobic digestion. After sludge land application, TCS majorly dissipates in the soil through biodegradation by fungi and bacteria , potentially posing environmental risks, such as inhibiting the seedling growth of plant species. Additionally, the degradation of TCS, coupled with the formation and subsequent degradation of MeTCS, is observed, with MeTCS exhibiting a higher half-life and greater toxicity than its parent compound (TCS). Overall, this research offers vital insights to enhance understanding of TCS's migration and degradation processes in sewage treatment and soil. It also provides guidance in environmental protection and sustainable resource management.
... High-throughput sequencing has permitted to explore the key microorganisms and to comprehend the shifts in the microbial communities with these indicated parameters [68]. For instance, studies have shown that the electrochemical properties of the target EPs in the BESs are one of the significant limitations allowing to decide if the BESs anode or cathode are suitable for their elimination [95]. Similarly, more negative applied potential enhances the removal of EPs and sharply shortens the hydraulic retention time (HRT) of biocathodes [96,97]. ...
... Furthermore, the carbon source plays a significant role between competition and commensalism of the electroactive, electricigenic anode respiring and electrogenic microbial bacterial community and its metabolism [100,101]. Both high salinity [102][103][104] and temperature [95,105,106] affect the bacterial growth that influences the biological activities and conductivity of wastewater that involves redox reaction rates in BESs [68]. ...
... Bacterial degradation plays a crucial role in determining the fate of environmental pollutants such as TCS and related compounds. In recent years, some bacteria have been found to degrade TCS, such as Sphingomonas sp, strain YL-JM2C (Mulla et al., 2016), Sphingopyxis strain KCY1 (Lee et al., 2012), Dyella sp. WW1 (Wang et al., 2018b), Shewanella putrefaciens CN32 (Wang et al., 2017a(Wang et al., , 2017b, and Sphingomonas sp. ...
... PH-07 (Kim et al., 2011) and Providencia rettgeri MB-IIT strain (Balakrishnan and Mohan, 2021). In the work of Mulla et al. (2016), Sphingomonas sp., strain YL-JM2C, isolated from activated sludge of a WWTP, is effective in degrading TCS. After optimizing the conditions, including temperature (30°C) and pH (7.0), strain YL-JM2C can completely mineralize TCS (5 mg/L) within 72 h. ...
Triclosan (TCS) has been widely used in daily life because of its broad-spectrum antibacterial activities. The residue of TCS and related compounds in the environment is one of the critical environmental safety problems, and the pandemic of COVID-19 aggravates the accumulation of TCS and related compounds in the environment. Therefore, detecting TCS and related compound residues in the environment is of great significance to human health and environmental safety. The distribution of TCS and related compounds are slightly different worldwide, and the removal methods also have advantages and disadvantages. This paper summarized the research progress on the source, distribution, degradation, analytical extraction, detection, and removal techniques of TCS and related compounds in different environmental samples. The commonly used analytical extraction methods for TCS and related compounds include solid-phase extraction, liquid-liquid extraction, solid-phase microextraction, liquid-phase microextraction, and so on. The determination methods include liquid chromatography coupled with different detectors, gas chromatography and related methods, sensors, electrochemical method, capillary electrophoresis. The removal techniques in various environmental samples mainly include biodegradation, advanced oxidation, and adsorption methods. Besides, both the pros and cons of different techniques have been compared and summarized, and the development and prospect of each technique have been given.
... With the help of enzymes, bacteria can convert TCS into less toxic constituents by biotransformation [163]. Bacteria such as KCYI, Dyella sp, Spingomonas sp, and N. europaea produce dioxygenase, and YL-JM2C bacteria produce chloro hydroquinone dehalogenase [110]. These enzymes have shown positive results in TCS degradation [37]. ...
... For example, A. versicolor has a tolerance level of 15.69 mg L − 1 which is higher compared to other fungal species [43]. Spingomonassp strain YL-JM2C bacteria have higher resistance to TCS than strains like Pseudomonas putida [110]. For this reason, domestication is extremely important for microbial removal of TCS. ...
... Bacteria are found to be most effective in TCS degradation due to their ability to synthesize a wide variety of enzymes. Mulla et al. [110] used response surface methodology to optimize conditions (30 • C and pH 7.0) to degrade TCS, where it was mineralized into 2,4 dichlorophenol (2,4, DCP), hydroquinone, and 2-chlorohydroquinone [176]. The stable isotope experiment results showed that YL-JM2C strain used some of the heavier carbon ( 13 C) labeled TCS to synthesize fatty acids while the 13 C 12 -TCS was mineralized into CO 2 [110]. ...
Triclosan (TCS) is an antimicrobial agent used widely in pharmaceutical and personal care products (PPCPs). The extensive use of TCS in PPCPs has increased over the past few decades and its sizeable production and consumption are causing adverse effects on the environment and humans. TCS has been made into the list of emerging micropollutants (EMPs) due to its omnipresence in water resources, and even in biological samples such as urine and breast milk. Therefore, it is imperative not only to understand the current status of TCS pollution, but their occurrence, exposure routes, and environmental risks to identify remediation technologies for mitigating TCS. Present review targets to provide the cumulative data on the abundance of emerging TCS in water resources and its associated health burdens, simultaneously. It is identified that TCS remediation can be achieved through advanced physical and chemical methods such as enzyme oxidation and ozonation. However, there are drawbacks such as high energy consumption and the formation of toxic by-products. Therefore, the article endeavors to provide an in-depth understanding of the biological remediation of TCS by microbial degraders as well as its superiority over other remediation techniques. Insights into the various microbial communities such as bacteria, algae, and fungi and their unique bioremediation mechanisms are comprehensively summarised. Moreover, challenges associated with existing bioremediation methods and future perspectives are also discussed in the present work.
... It is also used in numerous personal care products, e.g., hand creams, hand soaps, and toothpastes. There have been some microorganisms in nature like Sphingomonas, which are capable of degrading phenolic compounds like triclosan (Mulla et al., 2016). However, the influence of antimicrobial biocides, such as triclosan, on resistance spread among microorganisms is barely studied. ...
Growing resistance among microbial communities against antimicrobial compounds, especially antibiotics, is a significant threat to living beings. With increasing antibiotic resistance in human pathogens, it is necessary to examine the habitats having community interests. In the present study, a metagenomic approach has been employed to understand the causes, dissemination, and effects of antibiotic, metal, and biocide resistomes on the microbial ecology of three hot springs, Borong, Lingdem, and Yumthang, located at different altitudes of the Sikkim Himalaya. The taxonomic assessment of these hot springs depicted the predominance of mesophilic organisms, mainly belonging to the phylum Proteobacteria. The enriched microbial metabolism assosiated with energy, cellular processes, adaptation to diverse environments, and defence were deciphered in the metagenomes. The genes representing resistance to semisynthetic antibiotics, e.g., aminoglycosides, fluoroquinolones, fosfomycin, vancomycin, trimethoprim, tetracycline, streptomycin, beta-lactams, multidrug resistance, and biocides such as triclosan, hydrogen peroxide, acriflavin, were abundantly present. Various genes attributing resistance to copper, arsenic, iron, and mercury in metal resistome were detected. Relative abundance, correlation, and genome mapping of metagenome-assembled genomes indicated the co-evolution of antibiotic and metal resistance in predicted novel species belonging to Vogesella, Thiobacillus, and Tepidimona genera. The metagenomic findings were further validated with isolation of microbial cultures, exhibiting resistance against antibiotics and heavy metals, from the hot spring water samples. The study furthers our understanding about the molecular basis of co-resistomes in the ecological niches and their possible impact on the environment.
... Different geographical areas; assessment sites, including the skin, blood, or urine; exposure routes; duration; exposure levels; and laboratory methods may account for this inconsistency [15]. Furthermore, genetic factors may impact the metabolism of these compounds [32]. ...
... Our study indicates that TCS exposure potentially increases IgE levels, causing high susceptibility to allergic diseases. Several epidemiological studies have reported that urine TCS levels during pregnancy and in early childhood are associated with biomarkers of altered immune function, including increased levels of IgE, cytokines, and other inflammatory markers [32][33][34][35][36][37]. An experimental study in mice reported that dermal exposure to TCS increased the frequency of immune system biomarkers including B cells, T cells, and natural killer cells in skin lymph nodes [38]. ...
Background
Few studies have assessed associations between allergic diseases and antibacterial agents in Taiwanese children.
Objective
This study aimed to investigate the association of triclosan (TCS) exposure with allergic diseases among preschoolers, disease-specific IgE titers, and a child’s sex.
Methods
Pediatric data were obtained from the Childhood Environment and Allergic Diseases Study (CEAS; 2010) cohort, and their urine and blood samples were used to analyze TCS and IgE concentrations (age 3 group). Three years later, clinical data were obtained again from the age 3 group (age 6 group). Correlations of TCS levels at ages 3 and 6 years with IgE levels and allergic diseases were evaluated.
Results
The TCS levels were higher at age 3 than at age 6 (geometric mean, 1.05 ng/ml vs 0.37 ng/ml). TCS levels were positively correlated with serum IgE levels at ages 3 and 6 years. Asthma and atopic dermatitis were significantly associated with TCS (adjusted OR 1.14, 95% confidence interval [CI] 1.01–1.29; OR 1.22, 95% CI 1.05–1.41). Sex-stratified analysis revealed that TCS levels were positively correlated with IgE levels among boys in the age 6 group and significantly associated with asthma, allergic rhinitis, and atopic dermatitis among boys.
Significance
TCS exposure is associated with IgE levels and a potentially high risk of pediatric atopic disorders.
... Spin column kit (Qiagen, Hilden, Germany) was used to extract chromosomal DNA while purification of bacterial 16 S rRNA (1500) was done by using exonuclease I-Shrimp Alkaline phosphatase (Exo-SAP) (Darby et al., 2005). For the amplification of 200 ng/ µL of 16 S rRNA genes, PCR technique was applied using universal primers, 27F (AGAGTTTGATC(C/A)TGGCTCAG) and 1492R (TACGG (C/T) TACCTTGTTACGACTT) (Clarridge 2004;Mulla et al., 2016;. Amplicons of PCR amplified genes were sequenced by following the method of Sanger (Sanger et al., 2000) using ABI 3500xL genetic analyzer (Life Technologies, United States). ...
A biosurfactant producing bacterium was identified as Pseudomonas aeruginosa DNM50 based on molecular characterization (NCBI accession no. MK351591). Structural characterization using MALDI-TOF revealed the presence of 12 different congeners of rhamnolipid such as Rha-C8-C8:1, Rha-C10-C8:1, Rha-C10-C10, Rha-C10-C12:1, Rha-C16:1, Rha-C16, Rha-C17:1, Rha-Rha-C10:1-C10:1, Rha-Rha-C10-C12, Rha-Rha-C10-C8, Rha-Rha-C10-C8:1, and Rha-Rha-C8-C8. The radical scavenging activity of rhamnolipid (DNM50RL) was determined by 2, 3-diphenyl-1-picrylhydrazyl (DPPH) assay which showed an IC50 value of 101.8 μg/ ml. The cytotoxic activity was investigated against MDA-MB-231 breast cancer cell line by MTT (4,5-dimethylthiazol-2-yl-2,5-diphenyl tetrazolium bromide) assay which showed a very low IC50 of 0.05 μg/ ml at 72 h of treatment. Further, its activity was confirmed by resazurin and trypan blue assay with IC50 values of 0.01 μg/ml and 0.64 μg/ ml at 72 h of treatment, respectively. Thus, the DNM50RL would play a vital role in the treatment of breast cancer targeting inhibition of p38MAPK.
... Bradyrhizobium and Rhodopseudomonas proliferated in soils exposed to triclosan, due to their ability to encode pathways regarding the degradation of this xenobiotic compound [42]. Moreover, Mycobacterium and Sphingomonas are among a few taxa with ability to degrade triclosan [43,44]. Hay et al. [45] reported the ability of a Sphingomonas sp. to degrade high concentration of triclosan, i.e. 500 mg/L. ...
... In addition, 2-chlorohydroquinone and hydroquinone were also among the breakdown products identified in the effluent (Table 2; Figure 5). Bioconversion of 2,4-dichlorophenol to 2-chlorohydroquinone and successively to hydroquinone can also be an alternative catabolic route [44,49], since formation of chlorohydroquinone from monohydroxy-triclosan has been recently reported [50]. ...
Biotreatment of triclosan is mainly performed in conventional activated sludge systems, which, however, are not capable of completely removing this antibacterial agent. As a consequence, triclosan ends up in surface and groundwater, constituting an environmental threat, due to its toxicity to aquatic life. However, little is known regarding the diversity and mechanism of action of microbiota capable of degrading triclosan. In this work, an immobilized cell bioreactor was setup to treat triclosan-rich wastewater. Bioreactor operation resulted in high triclosan removal efficiency, even greater than 99.5%. Nitrogen assimilation was mainly occurred in immobilized biomass, although nitrification was inhibited. Based on Illumina sequencing, Bradyrhizobiaceae, followed by Ferruginibacter, Thermomonas, Lysobacter and Gordonia, were the dominant genera in the bioreactor, representing 38.40 ± 0.62% of the total reads. However, a broad number of taxa (15 genera), mainly members of Xanthomonadaceae, Bradyrhizobiaceae and Chitinophagaceae, showed relative abundances between 1% and 3%. Liquid Chromatography coupled to Quadrupole Time-Of-Flight Mass Spectrometry (LC-QTOF-MS) resulted in the identification of catabolic routes of triclosan in the immobilized cell bioreactor. Seven intermediates of triclosan were detected, with 2,4-dichlorophenol, 4-chlorocatechol and 2-chlorohydroquinone being the key breakdown products of triclosan. Thus, the immobilized cell bioreactor accommodated a diverse bacterial community capable of degrading triclosan.
... Mulla et al. got another Pseudomonas sphingosine identified as YL-JM2C from the activated sludge of the sewage treatment plant. Under the optimal degradation conditions of triclosan obtained by the response surface method, 5mg/L of triclosan was completely degraded within 72 h (Mulla et al. 2016). Through the analysis of the degradation process, they identified three main by-products, and found that Pseudomonas sphingosine also uses the intermediate metabolites to transform triclosan to fatty acids, indicating that cells will use intermediate metabolites in the process of catabolism. ...
With the enhancement of environmental protection awareness, research on the bioremediation of petroleum hydrocarbon environmental pollution has intensified. Bioremediation has received more attention due to its high efficiency, environmentally friendly by-products, and low cost compared with the commonly used physical and chemical restoration methods. In recent years, bacterium engineered by systems biology strategies have achieved biodegrading of many types of petroleum pollutants. Those successful cases show that systems biology has great potential in strengthening petroleum pollutant degradation bacterium and accelerating bioremediation. Systems biology represented by metabolic engineering, enzyme engineering, omics technology, etc., developed rapidly in the twentieth century. Optimizing the metabolic network of petroleum hydrocarbon degrading bacterium could achieve more concise and precise bioremediation by metabolic engineering strategies; biocatalysts with more stable and excellent catalytic activity could accelerate the process of biodegradation by enzyme engineering; omics technology not only could provide more optional components for constructions of engineered bacterium, but also could obtain the structure and composition of the microbial community in polluted environments. Comprehensive microbial community information lays a certain theoretical foundation for the construction of artificial mixed microbial communities for bioremediation of petroleum pollution. This article reviews the application of systems biology in the enforce of petroleum hydrocarbon degradation bacteria and the construction of a hybrid-microbial degradation system. Then the challenges encountered in the process and the application prospects of bioremediation are discussed. Finally, we provide certain guidance for the bioremediation of petroleum hydrocarbon-polluted environment.
... The photocatalytic experiments revealed that 100 mg L − 1 of 10% rGO-TiO 2 completely removed 1 mg L − 1 of TCS under 24 h exposure to sunlight (Kaur et al., 2020). Notably, low concentrations of TCS (<2 mg L − 1 ) can be converted by aerobes (e.g., Pseudomonas and Sphingomonas) and anaerobes (e.g., Dehalococcoides) through oxidation and reductive dechlorination, respectively (Mulla et al., 2016;Devatha and Pavithra, 2019;Zhao et al., 2020). ...
As replacements for “old” organohalides, such as polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs), “new” organohalides have been developed, including decabromodiphenyl ethane (DBDPE), short-chain chlorinated paraffins (SCCPs), and perfluorobutyrate (PFBA). In the past decade, these emerging organohalides (EOHs) have been extensively produced as industrial and consumer products, resulting in their widespread environmental distribution. This review comprehensively summarizes the environmental occurrence and remediation methods for typical EOHs. Based on the data collected from 2015 to 2021, these EOHs are widespread in both abiotic (e.g., dust, air, soil, sediment, and water) and biotic (e.g., bird, fish, and human serum) matrices. A significant positive correlation was found between the estimated annual production amounts of EOHs and their environmental contamination levels, suggesting the prohibition of both production and usage of EOHs as a critical pollution-source control strategy. The strengths and weaknesses, as well as the future prospects of up-to-date remediation techniques, such as photodegradation, chemical oxidation, and biodegradation, are critically discussed. Of these remediation techniques, microbial reductive dehalogenation represents a promising in situ remediation method for removal of EOHs, such as perfluoroalkyl and polyfluoroalkyl substances (PFASs) and halogenated flame retardants (HFRs).
