INTERNATIONAL BIODETERIORATION & BIODEGRADATION
·
2022
·
IF 4.907
Long Zhang,Man Song,Zhenbo Mao,Yuan Liu,Feng Li,Jiandong Jiang,Kai Chen
Dichlorprop [( R , S )-2-(2,4-dichlorophenoxy)propanoic acid], a chiral herbicide belonging to phenoxyalkanoic acid herbicides, is extensively used around the world, and is frequently detected in various habitats. Although ( S )-dichlorprop has no herbicidal activity, its toxicity and ecological risk are higher than ( R )-dichlorprop. In our previous studies, the isolated strain Sphingopyxis sp. DBS4 was confirmed to mineralize both ( R )-dichlorprop and ( S )-dichlorprop, but the key genes responsible for the initial degradation of ( R )-/( S )-dichlorprop were still unclear. Here, based on genome sequencing and enzyme purification , a new dioxygenase gene, spoA , responsible for the initial transformation of ( S )-dichlorprop to 2,4-dichlorophenol and pyruvate was cloned from the rac -dichlorprop-utilizing strain of Sphingopyxis sp. DBS4. SpoA, an α -ketoglutarate-dependent dioxygenase, exhibited low amino acid sequence identity to the reported ( S )-dichlorprop-transforming dioxygenase SdpA (34.8%), and showed enantioselective activity toward ( S )-enantiomers of dichlorprop and mecoprop, but no activity toward the corresponding ( R )-enantiomers. The K m value of SpoA for ( S )-dichlorprop was 134.3 μM, and the k cat / K m was determined to be 7.5 × 10 −2 μM −1 s −1 . Molecular docking and site-directed mutagenesis showed that two residues of SdpA, Lys101 and Asp119, are the key sites for the enantioselective transformation of ( S )-dichlorprop. Our study identifies a new dioxygenase for the enantioselective transformation of ( S )-dichlorprop and deepens our understanding of the microbial catabolism of chiral phenoxyalkanoic acid herbicides.
研究领域:
环境微生物学
·
酶学
·
生物降解
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产品关联
DOI
高影响因子
FOOD CHEMISTRY
·
2017
·
IF 4.529
Yashu Chen,Bijun Xie,Jifang Yang,Jigang Chen,Zhida Sun
Rhodococcus sp. B7740 is a newfound bacterium which was isolated from 25 m deep seawater in the arctic. In this paper, Rhodococcus sp. B7740 was firstly discovered to produce abundant natural isoprenoids, including ubiquinone-4(UQ-4), 13 kinds of menaquinones, three rare aromatic carotenoids and more than one common carotenoid. These compounds were identified by UV–Visible, HPLC-APCI-MS/MS and HRMS spectra. Results demonstrated that Rhodococcus sp. B7740 might be a worthy source of natural isoprenoids especially for scarce aromatic carotenoids. Among them, isorenieratene with 528.3762 Da (calculated for 528.3756 Da, error: 1.1 ppm), a carotenoid with aromatic ring, was purified by HSCCC. The stability of isorenieratene under the mimical gastric conditions was measured compared with common dietary carotenoids, β-carotene and lutein. Unlike β-carotene and lutein, isorenieratene exhibited rather stable in the presence of free iron or heme iron. Its high retention rate in gastrointestinal tract after ingestion indicates the benefits for health.
研究领域:
微生物学
·
营养学
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产品关联
DOI
PubMed
高影响因子
ARCHIVES OF MICROBIOLOGY
·
2024
·Vol. 206
·期 5
·1-13
·
IF 2.3
Peng Liang,Yun Hui,Ji Jing,Zhang Wenjie,Xu Ting,Li Si,Wang Zhenfei,Xie Li,Li Xiangkai
Ibuprofen (IBU) and naproxen (NPX), as widely prescribed non-steroidal anti-inflammatory drugs (NSAIDs), are largely produced and consumed globally, leading to frequent and ubiquitous detection in various aqueous environments. Previously, the microbial transformation of them has been given a little attention, especially with the isolated fungus. A yeast-like Apiotrichum sp. IB-1 has been isolated and identified, which could simultaneously transform IBU (5 mg/L) and NPX (2.5 mg/L) with maximum efficiencies of 95.77% and 88.31%, respectively. For mono-substrate, the transformation efficiency of IB-1 was comparable to that of co-removal conditions, higher than most of isolates so far. IBU was oxidized mainly through hydroxylation (m/z of 221, 253) and NPX was detoxified mainly via demethylation (m/z of 215) as shown by UPLC-MS/MS results. Based on transcriptome analysis, the addition of IBU stimulated the basic metabolism like TCA cycle. The transporters and respiration related genes were also up-regulated accompanied with higher expression of several dehydrogenase, carboxylesterase, dioxygenase and oxidoreductase encoding genes, which may be involved in the transformation of IBU. The main functional genes responsible for IBU and NPX transformation for IB-1 should be similar in view of previous studies, which needs further confirmation. This fungus would be useful for potential bioremediation of NSAIDs pollution and accelerate the discovery of functional oxidative genes and enzymes different from those of bacteria.
研究领域:
环境微生物学
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药理学
·
生物技术
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产品关联
DOI
PubMed
高影响因子
INTERNATIONAL BIODETERIORATION & BIODEGRADATION
·
2015
·
IF 2.131
Lin-Na Du,Gang Li,Yu-Hua Zhao,He-Kun Xu,Yang Wang,Ying Zhou,Liang Wang
We investigated biodegradation of the azo dye methyl orange (MO) by Aeromonas sp. DH-6. Nearly 100% decolorization of MO (100 mg l −1 ) by the strain was observed at pH 3.0–7.0 and a broad temperature range (5–45 °C) after incubation for 12 h. Most of the tested carbon and nitrogen sources could significantly enhance MO decolorization, but of the metal ions , only Mg 2+ , Mn 2+ , and 1.5 mM of Ca 2+ could increase the decolorization. The strain still showed a high capacity for decolorizing MO even at a concentration of up to 1000 mg l −1 . Based on the gas chromatography-mass spectrometry analysis (GC-MS) and high performance liquid chromatography analysis (HPLC) data, N,N-dimethyl- p -phenylenediamine and 4-aminobenzenesulfonic acid were identified as the main intermediates of MO biodegradation, and a possible degradation pathway was proposed. Moreover, results of enzyme analysis indicated that laccase, NADH-DCIP reductase, and azo reductase were responsible for the degradation. Overall, high biodegradation efficiency at a broad range of temperatures and dye concentrations suggested that strain DH-6 would have high potential in the bioremediation of azo dyes.
研究领域:
环境科学
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微生物学
·
染料降解
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产品关联
DOI
高影响因子
APPLIED MICROBIOLOGY AND BIOTECHNOLOGY
·
2023
·Vol. 107
·期 11
·3745-3761
·
IF 5
Xu Chenglong,Lin Wenxi,Chen Yunni,Gao Boliang,Zhang Zhibin,Zhu Du
Perylenequinones (PQs) are a class of natural polyketides used as photodynamic therapeutics. Heat stress (HS) is an important environmental factor affecting secondary metabolism of fungi. This study investigated the effects of HS treatment on PQs biosynthesis of Shiraia sp. Slf14(w) and the underlying molecular mechanism. After the optimization of HS treatment conditions, the total PQs amount reached 577 ± 34.56 mg/L, which was 20.89-fold improvement over the control. Also, HS treatment stimulated the formation of intracellular nitric oxide (NO). Genome-wide analysis of Shiraia sp. Slf14(w) revealed iNOSL and cNOSL encoding inducible and constitutive NOS-like proteins (iNOSL and cNOSL), respectively. Cloned iNOSL in Escherichia coli BL21 showed higher nitric oxide synthase (NOS) activity than cNOSL, and the expression level of iNOSL under HS treatment was observably higher than that of cNOSL , suggesting that iNOSL is more responsible for NO production in the HS-treated strain Slf14(w) and may play an important role in regulating PQs biosynthesis. Moreover, the putative biosynthetic gene clusters for PQs and genes encoding iNOSL and nitrate reductase (NR) in the HS-treated strain Slf14(w) were obviously upregulated. PQs biosynthesis and efflux stimulated by HS treatment were significantly inhibited upon the addition of NO scavenger, NOS inhibitor, and NR inhibitor, indicating that HS-induced NO, as a signaling molecule, triggered promoted PQs biosynthesis and efflux. Our results provide an effective strategy for PQs production and contribute to the understanding of heat shock signal transduction studies of other fungi.
Key points
• PQs titer of Shiraia sp. Slf14(w) was significantly enhanced by HS treatment . • HS-induced NO was first reported to participate in PQs biosynthetic regulation . • Novel inducible and constitutive NOS-like proteins (iNOSL and cNOSL) were obtained and their NOS activities were determined .
研究领域:
微生物学
·
分子生物学
·
药理学
·
生物技术
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产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Shijie Yao,Yaru Hu,Jianfeng Ye,Jianhao Xie,Xuetao Zhao,Lingli Liu,Shuguang Lyu,Kuangfei Lin,Changzheng Cui
The super-resistant bacteria that produce the New Delhi metallo-β-lactamase 1 (NDM-1) enzyme are becoming a conceivably major worldwide clinical issue with serious consequences. Studying the disinfection and mechanism of super-resistant bacteria and their antibiotic resistance genes (ARGs) is crucial for controlling their spread in the water environment. In this study, the disinfection of the super-resistant bacterium Acinetobacter sp. CS-2 and its transferable ARGs (plasmid-encoded bla NDM-1 and bla OXA-58 ) by ultraviolet radiation (UV), peroxymonosulfate (PMS), and ultraviolet/peroxymonosulfate (UV/PMS) exposure were investigated. UV/PMS could completely inactivate CS-2 and control the photoreactivation risk, while bacteria that underwent UV and PMS treatment had survival ratios of 0.22% and 0.28%, respectively. The removal efficiencies of bla NDM-1 and bla OXA-58 ranged from 3.64 to 4.05 log, and the advantage of UV/PMS treatment on ARGs damage was further identified by gel electrophoresis analysis. The removal efficiency of bla NDM-1 was lower than that of bla OXA-58 , which was attributed to the low number of adjacent 5′-TT-3′ harbored by bla NDM-1 . The removal rate constants of the ARGs by UV treatment were significantly correlated with the number of adjacent base pairs (e.g., 5′-TT-3′, 5′-CT-3′, 5′-TC-3′ and 5′-CC-3′) and length, with R -values ranging from 0.9044 to 0.9512. Singlet oxygen ( 1 O 2 ) played a vital role in the reduction of bla NDM-1 and bla OXA-58 in the UV/PMS treatment. UV/PMS showed high removal efficiency under natural pH conditions and in the presence of various aqueous ions (e.g., Cl − , SO 4 2− and HCO 3 − ). Overall, this study provides new understandings and theoretical support for the risk control of super-resistant bacteria and plasmid-encoded ARGs.
研究领域:
环境科学
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微生物学
·
分子生物学
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DOI
高影响因子
BIODEGRADATION
·
2018
·Vol. 29
·期 6
·593-603
·
IF 2.41
Shi Zhoukun,Dong Weiliang,Xin Fengxue,Liu Jiawei,Zhou Xinhai,Xu Fanli,Lv Ziyao,Ma Jiangfeng,Zhang Wenming,Fang Yan,Jiang Min
Abstract An acetamiprid-degrading fungus was isolated from contaminated soil and identified as Fusarium sp. strain CS-3 based on physiological, biochemical, and molecular analyses. Strain CS-3 exploited 50 mg/L as the sole carbon source in liquid culture, removing 98% in 96 h. Strain CS-3 retained its acetamiprid degradation abilities over a wide range of pH (5.0–8.0) and temperature (20–42 °C). HPLC–MS analysis showed that N ′-[(6-chloropyridin-3-yl)methyl]- N -methylacetamide, 2-chloro-5-hydroxymethylpyridine, and 6-chloronicotinic acid were identified as the most predominant metabolites, forming the basis for a newly described acetamiprid degradation pathway. Strain CS-3 efficiently degraded 99.6% of 50 mg/kg acetamiprid in soil, indicating potential for soil remediation. Graphical abstract
研究领域:
环境科学
·
微生物学
·
生物修复
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产品关联
DOI
PubMed
高影响因子
APPLIED CLAY SCIENCE
·
2018
·
IF 3.641
Bo Ruan,Pingxiao Wu,Xiaolin Lai,Huimin Wang,Liping Li,Liya Chen,Chunxi Kang,Nengwu Zhu,Zhi Dang,Guining Lu
The objective of this study was to investigate the interaction between stearic acid-modified montmorillonite (SA-Mt) and Sphingomonas sp. GY2B and its effect on the physical and chemical properties of montmorillonite in the 2 days' biodegradation of phenanthrene . Due to bacterial activities , surface and colloidal properties of the bacteria-treated sample evidently changed in comparison with the untreated SA-Mt. Changes in surface morphology and the agglomerate state of SA-Mt were clearly observed by scanning electron microscopy (SEM) after interaction with GY2B for 2 days. Although the interlayer space of SA-Mt structure remained basically unchanged, the decrease of the structural order and the appearance and shift of several absorbance bands in the Fourier transform infrared (FTIR) spectra verified the structural changes of SA-Mt after bacterial treatment . Besides, the second derivative infrared spectra indicated that bacterial growth and metabolism largely affected the microstructure in SA-Mt. Dissolution rates of major elements were obtained by inductively coupled plasma optical emission spectroscopy (ICP-OES) in the solution, which revealed that bacterial activities enhanced the release of major elements and brought about a significant higher dissolution of Si preferentially from the tetrahedral sheet edges of SA-Mt than Al. The improvement of elemental dissolution in the biotic experiment was attributed to the combined action of pH effect and ligand-promoted process. These results substantiated that microorganisms have a considerable influence on the physicochemical properties and structure in the clay-modulated biodegradation of organic compounds. This study has profound impacts on the clay-modulated biodegradation of hydrophobic organic contaminants in the environment.
研究领域:
环境科学
·
微生物学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY
·
2015
·Vol. 177
·期 6
·1229-1240
·
IF 1.735
Yu Xin-Jun,Yu Zhi-Qiang,Liu Ying-Liang,Sun Jie,Zheng Jian-Yong,Wang Zhao
High-fructose corn syrup (HFCS) is an agro-source product and has been the most commonly used substitute for sugar as sweetener in food industry due to its low price and high solution property. In this study, the F55 HFCS, rich in fructose and glucose, was first tested for biomass and docosahexaenoic acid productions as a mixed carbon source by a newly isolated Aurantiochytrium sp.YLH70. After the compositions of the HFCS media were optimized, the results showed that the HFCS with additions of metal ion and vitamin at low concentrations was suitable for biomass and docosahexaenoic acid productions and the metal ion and sea salt had the most significant effects on biomass production. During the 5-l fed-batch fermentation, total HFCS containing 180 g l −1 reducing sugar was consumed and yields of biomass, lipid, and DHA could reach 78.5, 51, and 20.1 g l −1 , respectively, at 114 h. Meanwhile, the daily productivity and the reducing sugar conversion yield for docosahexaenoic acid were up to 4.23 g l −1 day −1 and 0.11 g g −1 . The fatty acid profile of Aurantiochytrium sp.YLH70 showed that 46.4 % of total fatty acid was docosahexaenoic acid, suggesting that Aurantiochytrium sp.YLH70 was a promising DHA producer.
研究领域:
微生物学
·
生物技术
·
海洋生物技术
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产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2023
·
IF 8.6
Qu Zhang,Chao Xue,Gary Owens,Zuliang Chen
Biodegradation using free cells is limited to low cell density, biological activity, and subsequent cell collection and regeneration are difficult. Meanwhile the limitations of using graphene-based nanomaterials for the removing emerging contaminants are adsorption and required further regeneration. To address these problems, reduced graphene oxide (rGO) synthesized by green tea extract as the carrier served to immobilize Ochrobactrum sp. FJ1 to form a functional bionanomaterial (FJ1@rGO). Its function was to degrade 17beta-estradiol (E2). To obtain a highly functional bionanomaterial, response surface methodology (RSM) with central composite design (CCD) was deployed to evaluate the synthesis conditions, which guided the ability of FJ1@rGO to remove pollutants. Results show that inoculation amount and immobilization time greatly affect removal efficiency, and the efficiency in removing E2 utilizing the optimized FJ1@rGO reached 93.7 % within 10 days. This proved to be significantly higher than prior to optimization. To provide evidence for functional FJ1@rGO, a series of advanced characterization results confirmed that FJ1 was successfully immobilized on rGO. It appears that FJ1@rGO has: firstly, excellent removal effect on E1, BPA, and triclosan; and secondly, excellent recycling properties.
研究领域:
环境生物学
·
纳米生物学
·
污染治理
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产品关联
DOI
高影响因子
APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY
·
2014
·Vol. 175
·期 5
·2647-2658
·
IF 1.687
He Yu-Cai,Liu Feng,Zhang Dan-Ping,Gao Shan,Li Zhi-Qing,Tao Zhi-Cheng,Ma Cui-Luan
In this study, it was the first report that Bacillus sp. CCZU11-1 was used for the biotransformation of 1,3-propanediol cyclic sulfate (1,3-PDS) and its derivatives. The catalytic performance of Bacillus sp. sulfatase in the biotransformation of 1,3-PDS was significantly improved by biocatalyst permeabilization and immobilization. Using cell permeabilization, the hydrolytic activity of the whole-cell biocatalyst was increased by 3.5-fold after 1.5 h of pretreatment with 10 % ( v / v ) toluene at 30 °C and pH 7.0. Biotransformation of 20 mM 1,3-PDS for 24 h, 1,3-propanediol (1,3-PD) could be obtained in the yield of 97.4 % under the optimized reaction condition. Additionally, the immobilized biocatalysts, permeabilized cells entrapped in calcium alginate, and cross-linked enzyme aggregates were further employed to biotansform 1,3-PDS. Moreover, the total operational time of the immobilized biocatalysts could reach above 240 h with high conversion rate (>90 %).
研究领域:
生物化学
·
微生物学
✓ 已验证
DOI
PubMed
高影响因子
INTERNATIONAL MICROBIOLOGY
·
2024
·
IF 2.3
Zhang Mingle,He Zhimin,Xu Xiaoyi,Ji Fan,Wang Bin
This study investigates the advantages of combined microbial degradation of polycyclic aromatic hydrocarbons (PAHs) in reducing the inhibitory effects of high-concentration eluents commonly used in soil washing. A microbial synergistic strategy was proposed using Arthrobacter sp. SZ-3 and Pseudomonas putida B6-2 as the key bacteria in the presence of Tween 80. The results show that in systems with Tween 80, the SZ-3 strain exhibits a strong capacity to degrade three types of PAH compounds, while the B6-2 strain follows multiple degradation pathways. Mixed bacteria achieved degradation rates 60.70% higher than single bacteria at varying concentrations of Tween 80. Additionally, the average growth rates of mixed bacteria increased by 1.17–1.37 times, aligning with the changes in the functional group. Protein activity detection within each degradation system corresponded with growth quantity and the cyclic variation characteristics of ETS enzyme activity. Notably, the ETS activity of mixed bacteria was 150% higher than that of single bacteria. At a Tween 80 concentration of 500 mg/L, the degradation rates of PAHs (Phe, Flu, Pyr) by mixed bacteria were significantly higher than those by single bacteria. The catechol 1,2-dioxygenase activity of mixed bacteria was 2.30 times higher than that of single bacteria. While Tween 80 did not alter the PAH degradation pathways, it significantly influenced the accumulation amount and duration of the characteristic intermediate product. This provides a reference for the remediation of recalcitrant pollutants under conditions involving high-concentration surfactants.
研究领域:
环境微生物学
·
污染修复
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）