Pseudomonas aeruginosa CH7, isolated from activated sludge, was able not only to isomerize and degrade beta-cypermethrin but also to utilize it as the sole source of carbon and energy for growth and ...produce biosurfactant. The strain effectively degraded beta-cypermethrin with inocula biomass of 0.1–0.2gL−1 at 25–35°C, pH 6–9, and a final concentration of beta-cypermethrin 25–900mgL−1. Via response surface methodology analysis, we found the optimal condition was 29.4°C, pH 7.0, and inocula biomass of 0.15gL−1; under these conditions, about 90% of the beta-cypermethrin could be degraded within 12days. Noticeably, biosurfactant was detected in the MSM culture of strain CH7, suggesting that the biosurfactant (rhamnolipid) could potentially enhance the degradation of beta-cypermethrin by promoting the dissolution, adsorption, and absorption of the hydrophobic compounds. Therefore, CH7 may serve as a promising strain in the bioremediation of wastewater and soil polluted by beta-cypermethrin.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
•Three efficient aryl-OPFRs-degrading bacterial consortia were enriched from China.•These consortia exhibited excellent environmental adaptation (15–40 ℃, pH 5.0–12.0).•Strain Rhodococcus sp. YC-JH2 ...could utilize TPhP as sole carbon source for growth.•Strain Sphingopyxis sp. YC-JH3 could efficiently degrade TPhP (96.2% within 7 days).
Three bacterial consortia, named YC-SY1, YC-BJ1 and YC-GZ1, were enriched from different areas of China. Bacterial consortia YC-SY1, YC-BJ1 and YC-GZ1 could efficiently degrade triphenyl phosphate (TPhP) (100 mg/L) by approximately 79.4%, 99.8% and 99.6%, tricresyl phosphate (TCrP) by 90.6%, 91.9% and 96.3%, respectively, within 4 days. And they could retain high degrading efficiency under a broad range of temperature (15–40 ℃), pH (6.0–10.0) and salinity (0–4%). A total of 10 bacterial isolates were selected and investigated their degradation capacity. Among these isolates, two were significantly superior to the others. Strain Rhodococcus sp. YC-JH2 could utilize TPhP (50 mg/L) as sole carbon source for growth with 37.36% degradation within 7 days. Strain Sphingopyxis sp. YC-JH3 could efficiently degrade 96.2% of TPhP (50 mg/L) within 7 days, except that no cell growth was observed. Combined with 16S diversity analysis, our results suggest that the effective components of three bacterial consortia responsible for TPhP and TCrP degradation were almost the same, that is, bacteria capable of degrading TPhP and TCrP are limited, in this study, the most efficient component is Sphingopyxis. This study provides abundant microorganism sources for research on organophosphorus flame retardants (OPFRs) metabolism and bioremediation towards OPFRs-contaminated environments.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Bisphenol A is an important organic chemical as an intermediate, final and inert ingredient in manufacturing of many important products like polycarbonate plastics, epoxy resins, flame retardants, ...food-drink packaging coating, and other. BPA is an endocrine disruptor compound that mimics the function of estrogen causing damage to reproductive organs. Bacterial degradation has been consider as a cost effective and eco-friendly method for BPA degradation compared with physical and chemical methods. This study aimed to isolate and identify bacterial strain capable to degrade and tolerate high concentrations of this pollutant, studying the factors affecting the degradation process and study the degradation mechanism of this strain.
YC-AE1 is a Gram negative bacterial strain isolated from soil and identified as Pseudomonas putida by 16S rRNA gene sequence and BIOLOG identification system. This strain found to have a high capacity to degrade the endocrine disruptor Bisphenol A (BPA). Response surface methodology using central composite design was used to statistically optimize the environmental factors during BPA degradation and the results obtained by significant model were 7.2, 30 °C and 2.5% for optimum initial pH, temperature and inoculum size, respectively. Prolonged incubation period with low NaCl concentration improve the biodegradation of BPA. Analysis of variance (ANOVA) showed high coefficient of determination, R
and Adj-R
which were 0.9979 and 0.9935, respectively. Substrate analysis found that, strain YC-AE1 could degrade a wide variety of bisphenol A-related pollutants such as bisphenol B, bisphenol F, bisphenol S, Dibutyl phthalate, Diethylhexyl phthalate and Diethyl phthalate in varying proportion. Pseudomonas putida YC-AE1 showed high ability to degrade a wide range of BPA concentrations (0.5-1000 mg l
) with completely degradation for 500 mg l
within 72 h. Metabolic intermediates detected in this study by HPLC-MS were identified as 4,4-dihydroxy-alpha-methylstilbene, p-hydroxybenzaldeyde, p-hydroxyacetophenone, 4-hydroxyphenylacetate, 4-hydroxyphenacyl alcohol, 2,2-bis(4-hydroxyphenyl)-1-propanol, 1,2-bis(4-hydroxyphenyl)-2-propanol and 2,2-bis(4-hydroxyphenyl) propanoate.
This study reports Pseudomonas putida YC-AE1 as BPA biodegrader with high performance in degradation and tolerance to high BPA concentration. It exhibited strong degradation capacity and prominent adaptability towards a wide range of environmental conditions. Moreover, it degrades BPA in a short time via two different degradation pathways.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Notwithstanding the widespread use and promising clinical value of chemotherapy, the pharmacokinetics, toxicology, and mechanism of mitoxantrone remains unclear. To promote the clinical value in the ...treatment of human diseases and the exploration of potential subtle effects of mitoxantrone, zebrafish embryos were employed to evaluate toxicity with validated reference genes based on independent stability evaluation programs. The most stable and recommended reference gene was
, followed by
, for the 48 h post fertilization (hpf) zebrafish embryo mitoxantrone test, while both
and
were recommended as reference genes for the 96 hpf zebrafish embryo mitoxantrone test. With
as an internal control, we analyzed the mRNA levels of representative hepatotoxicity biomarkers, including
,
,
,
, cardiotoxicity biomarker
, and neurotoxicity biomarker
in the 48 hpf embryo mitoxantrone test. The mRNA levels of
,
, and
increased significantly in 10 and 50 μg/L mitoxantrone-treated 48 hpf embryos, while the transcript levels of
decreased in a dose-dependent manner, indicating that mitoxantrone induced hepatotoxicity and neurotoxicity. Liver hematoxylin⁻eosin staining and the spontaneous movement of embryos confirmed the results. Thus, the present research suggests that mitoxantrone induces toxicity during the development of the liver and nervous system in zebrafish embryos and that
is recommended as a potential biomarker for hepatotoxicity in zebrafish embryos. Additionally,
is proposed as a reference gene for the 48 hpf zebrafish embryo mitoxantrone toxicity test, while
and
are proposed as that for the 96 hpf test.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Background
Chloroplast is indispensable for plant response to environmental stresses, growth and development, whose function is regulated by different plant hormones. The chloroplast proteome is ...encoded by chloroplast genome and nuclear genome, which play essential roles in plant photosynthesis, metabolism and other biological processes. Ethylene response factors (ERFs) are key transcription factors in activating the ethylene signaling pathway and plant response to abiotic stress. But we know little about how ethylene regulates plastid function under drought stress condition. In this study we utilized tobacco overexpressing tomato ethylene responsive factor 1 (TERF1), an ERF transcription factor isolated from tomato, to investigate its effects on the plastid proteome under drought stress condition by method of iTRAQ technology.
Results
Results show that TERF1 represses the genes encoding the photosynthetic apparatus at both transcriptional and translational level, but the genes involved in carbon fixation are significantly induced by TERF1. TERF1 regulates multiple retrograde signaling pathways, providing a new mechanism for regulating nuclear gene expression. TERF1 also regulates plant utilization of phosphorus (Pi) and nitrogen (N). We find that several metabolic and signaling pathways related with Pi are significantly repressed and gene expression analysis shows that TERF1 significantly represses the Pi transport from root to shoot. However, the N metabolism is upregulated by TERF1 as shown by the activation of different amino acids biosynthesis pathways due to the induction of glutamine synthetase and stabilization of nitrate reductase although the root-to-shoot N transport is also reduced. TERF1 also regulates other core metabolic pathways and secondary metabolic pathways that are important for plant growth, development and response to environmental stresses. Gene set linkage analysis was applied for the upregulated proteins by TERF1, showing some new potential for regulating plant response to drought stress by TERF1.
Conclusions
Our research reveals effects of ethylene signaling on plastid proteome related with two key biological processes, including photosynthesis and nutrition utilization. We also provide a new mechanism to regulate nuclear gene expression by ERF1 transcription factor through retrograde signals in chloroplast. These results can enrich our knowledge about ERF1 transcription factor and function of ethylene signaling pathway.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
► Strain YZ-1 capable of degrading pyrethroids was isolated and identified. ► The genomic library of strain YZ-1 was constructed successfully. ► The cloned pytZ was a new pyrethroid-degrading gene. ► ...PytZ displayed broad substrate specificity, high enzyme activity and stability. ► It provided a favorable choice for the biodegradation of pyrethroids residues.
Strain YZ-1 was isolated from activated sludge and identified as Ochrobactrum anthropi. This strain was capable of degrading pyrethroids pesticides, suggesting the presence of degrading enzymes. In the present study, a novel esterase gene pytZ was cloned from the genomic library of YZ-1 successfully. The pytZ contained an open reading frame of 606bp encoding a pyrethroid-hydrolyzing carboxylesterase. Deduced amino acid sequence showed moderate identities (39–59%) with most homologous carboxylesterase, except a putative carboxylesterase from O. anthropi ATCC 49188 with the highest identity of 85%. Phylogenetic analysis revealed that PytZ belonged to esterase VI family. The gene pytZ showed no any sequence similarity with reported pyrethroid-hydrolyzing genes and was a new pyrethroid-degrading gene. PytZ was expressed in Escherichia coli BL21 (DE3) and purified using Ni-NTA Fast Start. PytZ was able to degrade various pyrethroids. The optimal temperature and pH were 35°C and 7.5. This enzyme was very stable over a wide range of temperature and pH. No cofactors were required for enzyme activity. Broad substrate specificity, high enzyme activity, and the favorable stability make the PytZ a potential candidate for the detoxification of pyrethroid residues in biotechnological application.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Serratia spp. strain JC1 and JCN13, isolated from activated sludge, could degrade and utilize beta-cypermethrin (beta-CP) as the sole carbon and energy sources for growth in the minimal salt media ...(MSM). The two strains could effectively degrade beta-CP with total inocula biomass 0.1–0.3
g dry wt
L
−1, at 20–38
°C, pH 6–9, initial beta-CP 25–1000
mg
L
−1 and metabolize it by cleavage of ester and diphenyl ether to yield 3-phenoxybenzoic acid (3-PBA) and phenol, then completely mineralize it. Response surface methodology (RSM) was used to optimize degradation conditions. Under their own optimal degradation conditions, strain JC1 could degrade 92% beta-CP within 10
days and the degradation rate of strain JCN13 reached 89% within 4
days. Cell surface hydrophobicity (CSH) and biodegradation assays indicated that JCN13 has higher hydrophobicity and degradation ability than JC1, and it means the high hydrophobicity of strains could enhance the degradation of beta-CP.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Bisphenol A (BPA) is a widespread pollutant threatening the ecosystem and human health. An effective BPA degrader YC-JY1 was isolated and identified as
sp. The optimal temperature and pH for the ...degradation of BPA by strain YC-JY1 were 30 °C and 6.5, respectively. The biodegradation pathway was proposed based on the identification of the metabolites. The addition of cytochrome P450 (CYP) inhibitor 1-aminobenzotriazole significantly decreased the degradation of BPA by
sp. YC-JY1.
BL21 (DE3) cells harboring pET28a-
achieved the ability to degrade BPA. The
gene knockout strain YC-JY1Δ
was unable to degrade BPA indicating that P450
was an essential initiator of BPA metabolism in strain YC-JY1. For BPA polluted soil remediation, strain YC-JY1 considerably stimulated biodegradation of BPA associated with the soil microbial community. These results point out that strain YC-JY1 is a promising microbe for BPA removal and possesses great application potential.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Mycobacterium
species exhibit high bioremediation potential for the degradation of polycyclic aromatic hydrocarbons (PAHs) that are significant environmental pollutants. In this study, three ...Gram-positive, rapidly growing strains (YC-RL4
T
, MB418
T
, and HX176
T
) were isolated from petroleum-contaminated soils and were classified as
Mycobacterium
within the family
Mycobacteriaceae
. Genomic average nucleotide identity (ANI; < 95%) and digital DNA–DNA hybridization (dDDH; < 70%) values relative to other
Mycobacterium
spp. indicated that the strains represented novel species. The morphological, physiological, and chemotaxonomic characteristics of the isolates also supported their affiliation with
Mycobacterium
and their delineation as novel species. The strains were identified as
Mycobacterium adipatum
sp. nov. (type strain YC-RL4
T
= CPCC 205684
T
= CGMCC 1.62027
T
),
Mycobacterium deserti
sp. nov. (type strain MB418
T
= CPCC 205710
T
= KCTC 49782
T
), and
Mycobacterium hippophais
sp. nov. (type strain HX176
T
= CPCC 205372
T
= KCTC 49413
T
). Genes encoding enzymes involved in PAH degradation and metal resistance were present in the genomes of all three strains. Specifically, genes encoding alpha subunits of aromatic ring-hydroxylating dioxygenases were encoded by the genomes. The genes were also identified as core genes in a pangenomic analysis of the three strains along with 70 phylogenetically related mycobacterial strains that were previously classified as
Mycolicibacterium
. Notably, strain YC-RL4
T
could not only utilize phthalates as their sole carbon source for growth, but also convert di-(2-ethylhexyl) phthalate into phthalic acid. These results indicated that strains YC-RL4
T
, MB418
T
, and HX176
T
were important resources with significant bioremediation potential in soils contaminated by PAHs and heavy metals.
Despites lots of characterized microorganisms that are capable of degrading phthalic acid esters (PAEs), there are few isolated strains with high activity towards PAEs under a broad range of ...environmental conditions. In this study,
sp. YC-JH1 had advantages over its counterparts in terms of di(2-ethylhexyl) phthalate (DEHP) degradation performance. It possessed an excellent degradation ability in the range of 20⁻50 °C, pH 5.0⁻12.0, or 0⁻8% NaCl with the optimal degradation condition 40 °C and pH 10.0. Therefore, strain YC-JH1 appeared suitable for bioremediation application at various conditions. Metabolites analysis revealed that DEHP was sequentially hydrolyzed by strain YC-JH1 to mono(2-ethylhexyl) phthalate (MEHP) and phthalic acid (PA). The hydrolase MphG1 from strain YC-JH1 hydrolyzed monoethyl phthalate (MEP), mono-n-butyl phthalate (MBP), mono-n-hexyl phthalate (MHP), and MEHP to PA. According to molecular docking and molecular dynamics simulation between MphG1 and monoalkyl phthalates (MAPs), some key residues were detected, including the catalytic triad (S125-H291-D259) and the residues R126 and F54 potentially binding substrates. The mutation of these residues accounted for the reduced activity. Together, the mechanism of MphG1 catalyzing MAPs was elucidated, and would shed insights into catalytic mechanism of more hydrolases.
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