Scientific Reports
·
2019
·Vol. 9
·期 1
·1-11
·
IF 4.011
Hu Chunhui,Zhao Shuxue,Li Kuiran,Yu Hao
A novel Alcaligenes sp. strain P156, which can utilize nicotinamide as its sole source of carbon, nitrogen and energy, was enriched and isolated from soil in a solid waste treatment plant. Aerobic growth and degradation with nicotinamide were characterized. Seven nicotinamide degradation-related genes were obtained by sequence alignment from the genome sequence of strain P156. Four genes, designated naaA , naaD , naaE and naaF , were cloned and heterologously expressed. Nicotinamide degradation is initiated by deamination to form nicotinic acid catalyzed by the nicotinamidase NaaA, which shares highest amino acid sequence identity (27.2%) with nicotinamidase from Arabidopsis thaliana . Nicotinic acid is converted to 6-hydroxynicotinic acid, which is further oxidized to 2,5-dihydroxypyridine (2,5-DHP). 2,5-DHP is then transformed to a ring-cleavage product, N -formylmaleamic acid, by an Fe 2+ dependent dioxygenase NaaD. N -formylmaleamic acid is transformed to fumaric acid through maleamic acid and maleic acid by NaaE and NaaF, respectively. To our knowledge, this is the first report of the complete microbial degradation of nicotinamide in bacteria. Nicotinamide is considered as a model compound for the study of microbial degradation of pyridinic compounds, and the nicotinamide degrading related genes in strain P156 were distributed differently from the reported similar gene clusters. Therefore, this study contribute to the knowledge on the degradation of pyridinic compounds.
研究领域:
微生物学
·
环境科学
·
基因组学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL TECHNOLOGY
·
2021
·
IF 3.247
Yangyang Wang,Qiang Ren,Wenhao Zhan,Kaixuan Zheng,Qi Liao,Zhihui Yang,Yansong Wang,Xinling Ruan
A previous isolated Gordonia sp. (Lff) was used to degrade di-n-octyl phthalate (DOP) contamination in both aqueous solution and soil. The influence of temperature, pH, inoculum size, salt content and initial concentration of DOP on DOP degradation by Lff were analysed. The response of soil bacterial community to DOP and Lff was also analysed by Illumina MiSeq sequence method. Results showed that the optimal temperature, pH, inoculum size and salt content were 35oC, 8.0, 5% and <5%, respectively. Under the optimal condition, more than 91.25% of DOP with different initial concentrations (100–2000 mg/L) could be degraded by Lff. Kinetics analysis indicated that biodegradation of DOP by Lff could be described by first-order kinetics (R2 > 0.917) with the half-life (t1/2) changing irregularly between 0.58 and 0.83 d. In addition, Lff enhanced the removal of DOP in soil and alleviated the toxicity of DOP on soil microorganisms. Furthermore, its influence on soil bacterial community is not obvious. These results suggested that Lff was effective in remediating DOP contamination in different environments.
研究领域:
环境科学
·
微生物学
✓ 已验证
DOI
高影响因子
CHEMOSPHERE
·
2014
·
IF 3.499
Feng Li,Lizhong Zhu
The effects of the surfactants, Tween 80 and sodium dodecyl benzene sulfonate (SDBS) on a membrane’s fatty acid composition and the transmembrane transport of phenanthrene were investigated. The results indicated that both surfactants could modify the composition of fatty acids of Citrobacter sp. Strain SA01 cells, 50 mg L −1 of both surfactants changed the composition of the fatty acids the most, increasing the amount of unsaturated fatty acids. The comparison of fatty acid profiles with diphenylhexatriene fluorescence anisotropy, a probe for plasma membrane fluidity, suggested that an increased amount of unsaturated fatty acids corresponded to greater membrane fluidity. In addition, increased unsaturated fatty acids promoted phenanthrene to partition from the extracellular matrix to cell debris, which increased reverse partitioning from the cell debris to the cytochylema. The results of this study were expected in that the addition of a surfactant is a simple and effective method for accelerating the rate-limiting step of transmembrane transport of hydrophobic organic compounds (HOCs) in bioremediation.
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
BIODEGRADATION
·
2018
·Vol. 29
·期 2
·129-140
·
IF 2.41
Mao Fei,Liu Xiaohong,Wu Kang,Zhou Chen,Si Youbin
Because of extensive sulfonamides application in aquaculture and animal husbandry and the consequent increase in sulfonamides discharged into the environment, strategies to remediate sulfonamide-contaminated environments are essential. In this study, the resistance of Shewanella oneidensis MR-1 and Shewanella sp. strain MR-4 to the sulfonamides sulfapyridine (SPY) and sulfamethoxazole (SMX) were determined, and sulfonamides degradation by these strains was assessed. Shewanella oneidensis MR-1 and Shewanella sp. strain MR-4 were resistant to SPY and SMX concentrations as high as 60 mg/L. After incubation for 5 days, 23.91 ± 1.80 and 23.43 ± 2.98% of SPY and 59.88 ± 1.23 and 63.89 ± 3.09% of SMX contained in the medium were degraded by S. oneidensis MR-1 and Shewanella sp. strain MR-4, respectively. The effects of the initial concentration of the sulfonamides and initial pH of the medium on biodegradation, and the degradation of different sulfonamides were assessed. The products were measured by LC–MS; with SPY as a substrate, 2-AP (2-aminopyridine) was the main stable metabolite, and with SMX as a substrate, 3A5MI (3-amino-5-methyl-isoxazole) was the main stable metabolite. The co-occurrence of 2-AP or 3A5MI and 4-aminobenzenesulfonic acid suggests that the initial step in the biodegradation of the two sulfonamides is S–N bond cleavage. These results suggest that S. oneidensis MR-1 and Shewanella sp. strain MR-4 are potential bacterial resources for biodegrading sulfonamides and therefore bioremediation of sulfonamide-polluted environments.
研究领域:
环境科学
·
微生物学
✓ 已验证
DOI
PubMed
高影响因子
PROCESS BIOCHEMISTRY
·
2018
·
IF 2.616
Mujiao Zhang,Peiyuan Yao,Shanshan Yu,Tongcun Zhang,Qiaqing Wu,Dunming Zhu
An efficient method for the production of 4-cyanobenzoic acid from terephthalonitrile was developed by using a novel nitrilase from Pantoea sp. AS-PWVM4 (PaNIT). Under the optimized reaction conditions (pH 8.0 and 37 °C), up to 100 g/L substrate concentration was almost completely converted to 4-cyanobenzoic acid with wet whole cells loading of 5.0 wt% in 4 h and the isolated yield was 91%. The substrate concentration, yield and productivity (26.13 g/(L h)) are much higher than those in the previous studies. Furthermore, PaNIT has broad substrate specificity of catalyzing the hydrolysis of various aromatic nitriles and aliphatic nitriles. These results suggest that PaNIT is a valuable nitrilase with potential practical applications.
研究领域:
生物化学
·
酶工程
·
有机合成
✓ 已验证
DOI
高影响因子
FOOD CHEMISTRY
·
2025
·
IF 9.8
Zhou Chen,Yanyin Song,Yuhan Yan,Wei Chen,Tong Ren,Aijin Ma,Siting Li,Yingmin Jia
A novel cellobiose 2-epimerase gene ( CsCEase1 ) from Clostridium sp. TW13 was successfully overexpressed. Cs CEase1, with a molecular mass of 45.0 kDa, exhibited a specific activity of 254.75 U/mg and showed optimal activity at 40 °C and pH 7.5. Using Cs CEase1, 44.30 % of lactose was converted into epilactose, yielding a production level of 26.58 g/L. An efficient purification method was developed, incorporating crystallization and β-galactosidase treatment to remove the unconverted lactose, while Saccharomyces cerevisiae was used to consume the produced glucose. Final purification with activated carbon resulted in epilactose with 98 % purity and a recovery rate of 66.47 %. Furthermore, Cs CEase1 was incubated with whey power and expired milk, achieving epilactose conversion rates of 29.65 % and 32.69 %, respectively. These findings highlight the potential of Cs CEase1 for the cost-effective and environmentally sustainable production of epilactose from dairy waste.
研究领域:
生物化学
·
食品科学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Processes
·
2023
·Vol. 11
·期 1
·255
·
IF 3.5
Ke Chen,Jingyun Zhang,Xing Liu,Peiyuan Zhang,Wenlong Yue,Zhiqiang Cai
Aspergillussp. D-23 was obtained by ultraviolet-diethyl sulfate (UV-DES) compound mutagenesis fromAspergillussp. C18 that the α-galactosidase was purified from. According to sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and non-denaturing polyacrylamide gel electrophoresis (Native-PAGE), the purified enzyme demonstrated apparent homogeneity. The monomeric α-galactosidase’s native molecular weight was 125 kDa. The optimal temperature of α-galactosidase was 65 °C, and 75% of the initial enzyme activity could be maintained between 45 and 55 °C. Its optimal pH was 5.0 with good pH stability. After incubating for 2 h at pH 3.0–8.0, it could retain more than 80% of its original activity. Different concentrations of metal ions had different effects on the α-galactosidase activity. High concentrations of Cu2+could strongly inhibit enzyme activity and low concentrations of Fe2+could promote enzyme activity. Additionally, as shown by thin layer chromatography and high-performance liquid chromatography, the enzyme also had good hydrolysis ability, which could efficiently hydrolyze melibiose and raffinose by more than 95%. Therefore, these excellent characteristics could make α-galactosidase a good candidate for the food and feed industries.Keywords:α-galactosidase;enzymatic characterization;Aspergillussp.;enzymatic hydrolysis;higher molecular weight
研究领域:
生物化学
·
食品科学
·
微生物学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2024
·
IF 12.2
Ganxing Liu,Hao An,Lei Tang,Zhewei Chi,Yunwen Bi,Zeqi Ye,Haiming Zhao,Lei Xiang,Naixian Feng,Cehui Mo,Delin Xu
Microbe-mediated DBP (dibutyl phthalate) mineralization is acknowledged to be affected by diverse extracellular factors. However, little is known about the regulatory effects from quorum sensing (QS) signals. In this study, extracellularly applied QS signals A-like (hydroxymethyl dihydrofuran) was discovered to significantly enhance DBP degradation efficiency in Streptomyces sp. SH5. Monobutyl phthalate , protocatechuic acid and beta-ketoadipate were discovered as degradation intermediates by HPLC-TOF-MS/MS. Multi-omics analysis revealed the up-regulation of multiple hydrolases, transferases and decarboxylases that potentially contributed to A-like accelerated DBP degradation. Transcription of Orf2708, an orthologue of global transcriptional activator, was significantly induced by A-like. Orf2708 was demonstrated to interact specifically with the promoter of hydrolase orf2879 gene by EMSA , and the overexpression of orf2879 led to an enhanced DBP degradation in SH5. Taken together with the molecular docking studies showing the stability of ligand-receptor complex of A-like and its potential receptor Orf3712, a hierarchical regulatory cascade underlying the QS signal mediated DBP degradation was proposed as A-like/Orf3712 duplex formation, enhanced orf2708 expression and the downstream specific activation of hydrolase Orf2879. Our study presents the first evidence of GBLs-type promoted DBP degradation among bacteria, and the elucidated signal transduction path indicates a universal application potential of this activation strategy.
研究领域:
微生物学
·
环境科学
·
分子生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Nanotechnology
·
2020
·Vol. 2020
·期 1
·8828878
·
IF 0
Theint Theint Win,Sikandar Khan,PengCheng Fu
The scientific consensus is now on developing a biocontrol agent that can cause cellular metabolic reprogramming against agricultural pathogens. Biosynthesis of silver nanoparticles was performed by using phytopathogenic fungi ( Alternaria sp.) isolated from banana cultivated soil. Alternaria sp. can grow very fast and produce high enough bioactive compounds. This study aims to biosynthesize silver nanoparticles (AgNPs) using fungal Alternaria sp.’s metabolites as a safe antifungal agent against plant pathogenic fungi ( Fusarium spp. and Alternaria sp.). To visualize the formation of AgNPs, analytical instruments were used, such as ultraviolet-visible (UV-Vis) spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, scanning transmission electron microscopy (STEM), energy dispersive X-ray (EDX), and elemental mapping. The UV-visible spectra showed a peak at 435 nm. Analysis of scanning transmission electron microscopy (STEM) micrographs evidenced that the size of synthesized silver nanoparticles ranged between 3 and 10 nm. The resulting AgNPs showed distinct antifungal activity against selected plant pathogenic fungi. Synthesized AgNPs have demonstrated remarkable potential for the use of antifungal compounds to combat plant diseases.
研究领域:
微生物学
·
纳米生物学
·
植物病理学
✓ 已验证
DOI
Water
·
2024
·Vol. 16
·期 3
·416
·
IF 3
Qiang Li,Yuehui He,Boyan Wang,Nanhai Weng,Lei Zhang,Kaichun Wang,Fengrong Tian,Mingsheng Lyu,Shujun Wang
The biological denitrification of low-C/N wastewater is a great challenge in treatment plants due to the lack of microorganisms with heterotrophic nitrification–aerobic denitrification (HN-AD) abilities. In this study,Bacillussp. L2 was isolated from aeration tank water samples using a nitrification medium and screened for its ability to perform HN-AD in low-C/N wastewater. The strain showed a maximum NH4+-N removal rate of 98.37% under low-C/N conditions. In the presence of a mixed N source, strain L2 was capable of completely removing NH4+-N within 24 h. Furthermore, optimal nitrogen removal conditions for strain L2 were found to be C/N = 9, pH = 9, and sodium acetate as the C source. Under optimal conditions, the strain was able to maintain a high NH4+-N removal rate under 0–3% salinity and an NH4+-N concentration of 200 mg/L or less. The denitrification pathways of strain L2 were NH4+→NH2OH→NO2−(↔NO3−)→NO→N2O→N2and NH4+→NH2OH→NO→N2O→N2. Furthermore, semi-continuous wastewater treatment was conducted using immobilized technology, which resulted in more than 82% NH4+-N removal after three cycles of reuse. This study demonstrates the great potential ofBacillussp. L2 in wastewater treatment applications.
研究领域:
环境微生物学
·
污水处理
✓ 已验证
产品关联
DOI
高影响因子
Biotechnology Journal
·
2015
·Vol. 11
·期 2
·228-237
·
IF 3.49
Tian Ma,Yuanjie Zhou,Xiaowei Li,Fayin Zhu,Yongbo Cheng,Yi Liu,Zixin Deng,Tiangang Liu
As a highly valued keto-carotenoid, astaxanthin is widely used in nutritional supplements and pharmaceuticals. Therefore, the demand for biosynthetic astaxanthin and improved efficiency of astaxanthin biosynthesis has driven the investigation of metabolic engineering of native astaxanthin producers and heterologous hosts. However, microbial resources for astaxanthin are limited. In this study, we found that the α-Proteobacterium Sphingomonas sp. ATCC 55669 could produce astaxanthin naturally. We used whole-genome sequencing to identify the astaxanthin biosynthetic pathway using a combined PacBio-Illumina approach. The putative astaxanthin biosynthetic pathway in Sphingomonas sp. ATCC 55669 was predicted. For further confirmation, a high-efficiency targeted engineering carotenoid synthesis platform was constructed in E. coli for identifying the functional roles of candidate genes. All genes involved in astaxanthin biosynthesis showed discrete distributions on the chromosome. Moreover, the overexpression of exogenous E. coli idi in Sphingomonas sp. ATCC 55669 increased astaxanthin production by 5.4-fold. This study described a new astaxanthin producer and provided more biosynthesis components for bioengineering of astaxanthin in the future. Graphical Limited microbial resources for astaxanthin limit its widespread applications in nutritional supplements and pharmaceuticals. Sphingomonas sp. ATCC 55669 can produce astaxanthin naturally. Whole-genome sequencing with gene functional confirmation identifies the discrete astaxanthin biosynthetic genes, and overexpressed related genes in E. coli can increase astaxanthin production. The new astaxanthin producer and biosynthesis components provide more possibilities for bioengineering of astaxanthin in the future.
研究领域:
微生物学
·
生物工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2014
·Vol. 4
·期 86
·45920-45929
·
IF 3.708
Lisha Tan,Jiang Xu,Xiaoqin Xue,Zimo Lou,Jin Zhu,Shams Ali Baig,Xinhua Xu
Silica-coated magnetite (Fe3O4@SiO2) nanoparticles functionalized with amino, imino and sulfonic groups (Fe3O4@SiO2–mPD/SP) were successfully synthesized via a facile chemical oxidative polymerization of m-phenylenediamine (mPD) and m-sulfophenylenediamine-4-sulfonic acid (SP) monomers, and utilized for selective removal of Pb(II) and Cr(VI) from aqueous solutions. It was revealed by the characterizations that the polymers formed on Fe3O4@SiO2 nanoparticles were the true copolymers with a mPD–SP unit, rather than a mixture of mPD and SP homopolymers. Fe3O4@SiO2–mPD/SP nanocomposites could be easily separated from aqueous solutions within 30 s. The maximum adsorption capacities of Pb(II) (83.23 mg g−1) and Cr(VI) (119.06 mg g−1) on Fe3O4@SiO2–mPD/SP nanocomposites were obtained at the mPD/SP molar ratios of 95 : 5 and 50 : 50, respectively. Moreover, satisfactory selective removal of Pb(II) and Cr(VI) from their mixtures with Cu(II) and Ni(II) ions were exhibited by the Fe3O4@SiO2–mPD/SP (95 : 5) and Fe3O4@SiO2–mPD/SP (50 : 50), respectively. The Pb(II) adsorption equilibrium was reached within 5 min by Fe3O4@SiO2–mPD/SP (95 : 5). The adsorption data of Pb(II) and Cr(VI) were both fitted well to the Freundlich isotherm and followed the pseudo-second-order kinetic model. The adsorption mechanism of Pb(II) and Cr(VI) on Fe3O4@SiO2–mPD/SP nanocomposites included five processes, namely: ion-exchange, complexation adsorption, reduction reaction, electrostatic attraction and physical adsorption. The enhanced adsorption performance of nanoparticle-based magnetic adsorbents for selective removal of heavy metal ions can be achieved with such a copolymerization strategy.
研究领域:
环境科学
·
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）