JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE
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2022
·Vol. 102
·期 11
·4522-4531
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IF 4.125
Fen Yan,Junying Chen,Ting Cai,Jinfu Zhong,Shaolong Zhang
BACKGROUND Alginate oligosaccharides (AOS), with various physiological effects, have been widely used in the food, agricultural, and pharmaceutical industries. The biological enzymatic method of preparing AOS, using alginate lyase, has more advantages compared with physical and chemical methods. Cloning and heterologously expressing alginate lyase are therefore very important. RESULTS A novel alginate lyase, BY17PV7, from Microbulbifer sp. BY17, isolated from Gracilaria , was cloned and expressed in Escherichia coli BL21(DE3). BY17PV7 was about 27 KDa. BY17PV7 showed the greatest activity (150.42 ± 3.32 U/mg) at 43 °C and pH 8.9. It could be activated by Ca 2+ , Mn 2+ , Co 2+ , Fe 3+ , Na + , and inhibited by Mg 2+ , Zn 2+ , Ba 2+ , Cu 2+ , sodium dodecyl sulfate (SDS), ethylene diamine tetraacetic acid (EDTA). BY17PV7 had a wide range of substrate specificity and good degradation effects for poly β-D-mannuronate (polyM) and poly α-L-guluronate (polyG), demonstrating that it is a bifunctional alginate lyase. The kinetic parameters showed that BY17PV7 had a greater affinity for polyG. BY17PV7 released AOS with a degree of polymerization (DP) of 3–4 in an endolytic manner from sodium alginate. Alginate oligosaccharides showed strong antioxidant ability of reducing Fe 3+ and scavenging radicals such as hydroxyl, 2,2-azion-bia (3-ethylbenzo-thiazoline-6-sulfonic acid diammonium salt) (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH). CONCLUSION A novel bifunctional alginate lyase, BY17PV7, was expressed and characterized in Escherichia coli BL21(DE3). The results were helpful for the analysis of the molecular mechanisms of degrading patterns in the polysaccharide lyase (PL) family. © 2022 Society of Chemical Industry.
研究领域:
生物化学
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酶学
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食品科学
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药剂学
✓ 已验证
DOI
PubMed
高影响因子
CHEMOSPHERE
·
2022
·
IF 8.943
Jie Cheng,Kaidian Zhang,Jiashun Li,Yuyong Hou
Increased hazardous substances application causes more environmental pollution and risks for human health. Microalgae are the important biological groups in marine ecosystem, and considered to be sensitive to environmental pollutants. Therefore, toxicity test on marine microalgae could provide the most efficient method for aquatic toxicity assessment, and could also be used as the early warning signals in aquatic ecosystem . In view of this, our study aimed at investigating the toxicity potential of two typical organic compounds, and screening out novel photosynthetic indicators for the risk assessment of environmental pollutants. In this study, benzyl alcohol and 2-phenylethanol were chosen as the target organic compounds, and preliminary toxicity mechanism of these organic compounds on marine cyanobacterium Synechococcus sp. PCC7002 was investigated with chlorophyll fluorescence technology. Results showed that PCC7002 could be affected by benzyl alcohol or 2-phenylethanol stress, and the toxicity effect was concentration-dependent. And external benzyl alcohol and 2-phenylethanol stress damaged the oxygen evolving complex, and suppressed electron transport at the donor and receptor sides of photosystem II (PSII), influencing the absorption, transfer, and application of light energy. Furthermore, potential biomarkers were screened by half maximal inhibitory concentration (IC 50 ) on the basis of pearson correlation coefficient analysis, and fluorescence intensity difference between the I-step and P-step of OJIP curve (δF IP ) seems to be the most sensitive indicator for external stress. This study would be of significant interest to the biomarker community, and pave the way for the practical resource for marine pollution monitoring and assessment.
研究领域:
生态毒理学
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环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
STARCH-STARKE
·
2019
·
IF 1.795
Li Zhoukun,Zheng Wenwen,Zhang Lei,Wang Yanxin,Zhang Yajuan,Qiao Yan,Luo Xue,Huang Yan,Cui Zhongli
The enzyme 4-α-glucanotransferase catalyzes the intramolecular and intermolecular transglycosylation of α-1,4-glucan, which plays an important role in starch metabolism and starch modification. In this study, the gene encoding a 4-α-glucanotransferase from Corallococcus sp. EGB ( ccGtase ) is cloned and expressed in Escherichia coli BL21 (DE3). CcGtase contains all the conserved amino acid residues of glycoside hydrolase family 77 (GH77), which form the active site environment of the enzymes in the α-amylase family, while sequence alignments show that 4-α-glucanotransferases from myxobacteria constitute an independent group along with the GH77 glucanotransferases. Product analysis shows that CcGtase is able to convert malto-oligosaccharides and starch into linear maltooligosaccharides with a low degree of polymerization (DP < 12) instead of cycloamylose. The transfer action toward starch is only observed in the presence of glucose, and delayed production of maltose from the transfer reaction is also observed. During the reaction, no apparent hydrolytic activity is observed. Based on the low sequence identity (9–35%) and unique characteristics, CcGtase can be regarded as a new member of the GH77 family.
研究领域:
生物化学
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分子生物学
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酶学
✓ 已验证
DOI
高影响因子
PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY
·
2024
·
IF 4.2
Ke Xu,Xin-Ran Ke,Wan-Ting Zhang,Xin-Yuan Wu,Zhi-Jun Song,Mei-Juan Jiao,Xiao-Juan Gao,Li Zhou,Hong-Yan Ji,Fang Wang,Xiu-Li Wu
Imidacloprid (IMI) and diuron (DIU) are widely used pesticides in agricultural production. However, their excessive use and high residues have caused harm to the ecological environment and human health. Microbial remediation as an efficient and low-toxic method has become a research hotspot for controlling environmental pollutants. A fungus QHSH-33, identified as Simplicillium sp., has the ability to degrade neonicotinoids IMI and phenylurea DIU. When QHSH-33 and pesticide were co-cultured in liquid medium for 7 days, the degradation rates of IMI and DIU by QHSH-33 in simulated field soil microenvironment were 50.19 % and 70.57 %, respectively. Through HPLC-MS analysis, it was found that the degradation of IMI mainly involved nitro reduction, hydroxylation and other reactions. Three degradation pathways and eight degradation products were identified, among which two metabolites were obtained by microbial transformation of IMI for the first time. The degradation of DIU mainly involved demethylation and dehalogenation reactions, and two degradation pathways and four degradation products were identified, one of which was a new degradation product of DIU. Toxicity assessment demonstrated that most of the degradation products might be considerably less harmful than IMI and DIU. Whole genome sequencing of QHSH-33 revealed a genome size of 33.2 Mbp with 11,707 genes. The genome of QHSH-33 was annotated by KEGG to reveal 128 genes related to exogenous degradation and metabolism. After local blast with reported IMI and DIU degrading enzymes, seven IMI-degrading related genes and seven DIU-degrading related genes were identified in the QHSH-33 genome. The results of this study will help to expand our knowledge on the microbial decomposition metabolism of IMI and DIU, and provide new insights into the degradation mechanism of IMI and DIU in soil and pure culture system, laying a foundation for QHSH-33 strain applied to the removal, biotransformation or detoxification of IMI and DIU.
研究领域:
环境科学
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微生物学
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基因组学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
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2022
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IF 14.224
Huaxin Lei,Jiayu Zhang,Jin Huang,Dengjin Shen,Yin Li,Rui Jiao,Renxin Zhao,Xiaoyan Li,Lin Lin,Bing Li
The aerobic, lincomycin-degrading bacterial strain Conexibacter sp . LD01, belonging to the phylum Actinobacteria, was isolated from activated sludge . Both second- and third-generation sequencing technologies were applied to uncover the genomic characterization and high-quality genome with 99.2% completeness and 2.2% contamination was obtained. The biodegradation kinetics of lincomycin fit well with the modified Gompertz model ( R 2 > 0.97). Conexibacter sp . LD01 could subsist with lincomycin as the sole source of carbon, nitrogen, and energy. When 500 mg/L of glucose was added as a co-substrate, the biodegradation rate improved significantly, whereas the addition of 500 mg/L sodium pyruvate had a slight inhibitory effect. Ammonia nitrogen was the best nitrogen source for Conexibacter sp . LD01 when growing and degrading lincomycin. In total, 17 metabolic products consisting of nine novel products were detected, and five biodegradation pathways, including N-demethylation, breakage of the amido bond, sulfoxidation, and oxidation of the pyrrolidine ring and propylamino chain, were proposed. This study significantly expands our understanding of the functional microorganisms and mechanism involved in lincomycin biodegradation at the phylum level.
研究领域:
微生物学
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环境科学
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基因组学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF BIOTECHNOLOGY
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2025
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IF 3.9
Yu-Zhen Li,Qi Wang,Cheng Cheng,Chao Chen,Feng-Li Zhang,Yue Zou,Jun Li,Xin-Qing Zhao
Endophytic yeast strains are promising sources of various valuable bioactive compounds. However, studies on endophytic strains derived from lichen samples remains limited. In this study, we isolated and characterized Rhodotorula sp. Y090 from Usnea longissima and investigated its biosynthetic potential. Genome mining revealed distinct genetic features that differed from its closest relative strain R. graminis WP1. Ergothioneine (EGT) is a potent antioxidant and rare sulfur-containing histidine derivative. However, so far, the EGT biosynthetic enzymes by natural yeast strains have been limitedly studied. In this study, combining genome mining and transcriptomic analysis, genes encoding the potential enzymes for the production of EGT and xylose utilization were identified in Rhodotorula sp. Y090. Further studies demonstrated that Rhodotorula sp. Y090 was capable of producing EGT using xylose, glucose, glycerol, and sucrose as the sole carbon sources, and the highest titer reached 363.6 mg/L in shake flask culture, which is significantly higher than that of the most reported levels in the other natural yeasts. Rhodotorula sp. Y090 also exhibited a good ability of EGT export, which could facilitate cost-effective production. These findings suggest that the lichen-derived endophytic yeast Rhodotorula sp. Y090 represents a promising natural candidate for bio-production of the potent antioxidant.
研究领域:
微生物学
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生物化学
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基因组学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
BIORESOURCE TECHNOLOGY
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2019
·
IF 6.669
Lei Yu,Peng-tao Wang,Qing-tao Xu,Tao He,George Oduro,Yan Lu
In this study, magnetic humic acid (MHA) nanoparticle was prepared and confirmed the enhancement on reduction of azo dyes under high salt concentration. The anaerobic growth of the strain Bacillus sp. on quinones makes the biogenic hydroquinone feasible, and the latter was proven to reduce the azo dyes stoichiometrically. This in-situ reversibly oxidation and reduction of MHA acts as electron shuttle to catalyze the biotic reduction of the azo dyes. The biodegradation efficiencies in batch experiments and sequencing batch reactor with MHA were increased by 1.5–2.5 times as compared to that of control without the catalyzer. Moreover, the negligible leaching of HA under various environmental conditions suggests the robustness of the coating of HA on Fe/O surface. These results indicated that the as-prepared MHA could be used as redox mediator to accelerate the extracellular electron transfer, which is of great environmental significance for the removal of hazardous compounds.
研究领域:
环境科学
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微生物学
✓ 已验证
DOI
PubMed
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
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2022
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IF 10.753
Zhen Han,Qihua Lin,Shusheng Zhang,Xinru Zhou,Si Li,Faqian Sun,Chaofeng Shen,Xiaomei Su
Polychlorinated biphenyl (PCB)-degrading strains resuscitated by resuscitation promoting factor (Rpf) enlarged pure degraders to screen effective bio-inoculants for soil bioaugmentation . In this study, whole-genome analysis and PCB-degrading performance of a resuscitated strain LS1 were investigated. Importantly, the persistence and the physiological response of soil-inoculated LS1 were checked. The results indicate that the Bacillus sp. strain LS1 possessed the potential to degrade polycyclic aromatic compounds. LS1 exhibited better performance in degrading PCBs 18 and 52, but lower PCB 77 degradation capability. At PCBs concentration of 10 mg/L, the degradation efficiencies of PCBs 18, 52 and 77 within 96 h were 62.8 %, 59.6 % and 39.8 %, respectively. Combined the bph genes and metabolites detected, as well as the genes found in the genome, the abilities of LS1 for oxidative dehalogenation and mineralization of PCBs via HOPDA-benzoate-protocatechuate- β -ketoadipate pathway were determined. Notably, LS1 can still maintain survival and culturable state after inoculation into PCB-contaminated soil for 70 days. This is the first report to demonstrate the fate of resuscitated strain when used as soil bio-inoculant, which revealed the necessity and feasibility of using resuscitated strains to enhance bioremediation of PCB-contaminated soils.
研究领域:
环境科学
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微生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CURRENT MICROBIOLOGY
·
2016
·Vol. 74
·期 2
·193-202
·
IF 1.519
Xia Zhen-Yuan,Zhang Long,Zhao Yan,Yan Xin,Li Shun-Peng,Gu Tao,Jiang Jian-Dong
In this study, a bacterial strain of Achromobacter sp. LZ35, which was capable of utilizing 2,4-dichlorophenoxyacetic acid (2,4-D) and 2-methyl-4-chlorophenoxy acetic acid (MCPA) as the sole sources of carbon and energy for growth, was isolated from the soil in a disused pesticide factory in Suzhou, China. The optimal 2,4-D degradation by strain LZ35 occurred at 30 °C and pH 8.0 when the initial 2,4-D concentration was 200 mg L −1 . Strain LZ35 harbored the conserved 2,4-D/alpha-ketoglutarate dioxygenase (96%) and 2,4-dichlorophenol hydroxylase (99%), and catabolized 2,4-D via the intermediate 2,4-dichlorophenol. The inoculation of 7.8 × 10 6 CFU g −1 soil of strain LZ35 cells to 2,4-D-contaminated soil could efficiently remove over 75 and 90% of 100 and 50 mg L −1 2,4-D in 12 days and significantly released the phytotoxicity of maize caused by the 2,4-D residue. This is the first report of an Achromobacter sp. strain that was capable of mineralizing both 2,4-D and MCPA. This study provides us a promising candidate for its application in the bioremediation of 2,4-D- or MCPA-contaminated sites.
研究领域:
环境微生物学
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生物修复
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环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2016
·
IF 5.393
Hui Yun,Bin Liang,Jiguo Qiu,Long Zhang,Youkang Zhao,Jiandong Jiang,Aijie Wang
Haloaromatic antimicrobial triclocarban (3,4,4′-trichlorocarbanilide, TCC) is a refractory contaminant which is frequently detected in various aquatic and sediment environments globally. However, few TCC-degrading communities or pure cultures have been documented, and functional enzymes involved in TCC biodegradation hitherto have not yet been characterized. In this study, a bacterial strain, Ochrobactrum sp. TCC-2, capable of degrading TCC under both aerobic and anaerobic conditions was isolated from a sediment sample. A novel amidase gene (tccA), responsible for the hydrolysis of the two amide bonds of TCC and its dehalogenated congeners 4,4′-dichlorocarbanilide (DCC) and carbanilide (NCC) to more biodegradable chloroaniline or aniline products, was cloned and characterized. TccA shares low amino acid sequence identity (27 to 38%) with other biochemically characterized amidases and contains the conserved catalytic triad (Ser-Ser-Lys) of the amidase signature enzyme family. TccA was stable over a pH range of 5.0 to 10.0 and at temperatures lower than 60 °C, and it was constitutively expressed in strain TCC-2. In contrast to the halogenated TCC and DCC, the nonchlorinated NCC was the preferred substrate for TccA. TccA also had hydrolysis activity to a broad spectrum of amide bonds in herbicides, insecticides, and chemical intermediates. The constitutive expression and broad substrate spectrum of TccA suggested strain TCC-2 may be potentially useful for bioremediation applications.
研究领域:
环境微生物学
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生物降解
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酶学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2022
·
IF 14.224
Ailin Zhang,Yanhua Hou,Quanfu Wang,Yatong Wang
Biotreatment of polyethylene (PE) waste is an emerging topic in environmental remediation; in particular, the degrading enzymes requires further exploration. This study described a novel cold-adapted laccase (PsLAC) from an Antarctic psychrophile and characterized its PE-degradation ability. Homology modeling revealed that PsLAC possessed a typical bacterial laccase catalytic structure and unique cold adaptation structural characteristics such as few hydrogen bonds . Recombinant PsLAC (rPsLAC) retained 54.3% residual activity at 0 ℃ and presented increased K m values at low temperatures and a relatively high k cat value (42.65 s −1 ). Collectively, these factors help resist cold stress. rPsLAC possessed substantial salt tolerance at 1.5 M NaCl, with 119.80% activity, and Cu 2+ enhanced its activity to 127.10%. PE-degradation experiments indicated that 13.2% weight was lost, and the water contact angle was decreased to 74.6°. Polar functional groups such as carbonyl and carboxyl groups on PE surface were detected in Fourier transform infrared spectroscopy ; X-ray diffraction exhibited that crystallinity reduced by 25%. Enormous damage to PE surface and interior was observed via scanning electron microscopy. Overall, PsLAC, with its unique cold-adapted catalytic structure and biochemical characteristics, could supplement the diversity of sources and properties of bacterial laccases and ensure PE-degradation with a novel cold-adapted enzyme resource.
研究领域:
环境科学
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微生物学
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生物技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMOSPHERE
·
2020
·
IF 5.778
Jing-qiu Hua,Rui Zhang,Rong-ping Chen,Guang-xiang Liu,Ke Yin,Lei Yu
A highly efficient bioflocculant, i . e ., Na-Bsp was successfully prepared by using a tolerant strain- Bacillus sp. under high-salt condition without sterilization. Salt-containing medium was not infected by other strains throughout the whole incubation period in 168 h. The as-prepared Na-Bsp was found to be cation-dependent, exhibiting high flocculant efficiency (FE) i.e., 97.69 ± 0.61%, towards kaolin particles by aid of Fe 3+ . High FE values were well maintained under a wide pH range and/or boiled water treatment , likely because of the main constituent of polysaccharide . The presence of hydroxyl, carboxyl, and amine groups on the bioflocculant surface were possibly responsible for strong interactions with heavy metals. The adsorption capacities of Pb 2+ , Cu 2+ and Cr 6+ were 1000.0, 434.8 and 384.6 mg g −1 , respectively. The changing of structure and configuration of bioflocculant during the metal adsorption were explored by the scanning electron microscope with electron energy loss spectroscopy and three-dimensional excitation-emission fluorescence spectrometry . This study provided a novel production method, whereby the conventional sterilization could be avoided, which is of great environmental significance for steam-saving. Furthermore, the as-prepared Na-Bsp exhibited high adsorption capacities toward heavy metals, which sheds lights on its potential usage as an alternative adsorbent.
研究领域:
环境生物学
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微生物学
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污染控制
✓ 已验证
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）