ENVIRONMENTAL GEOCHEMISTRY AND HEALTH
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2024
·Vol. 46
·期 8
·1-12
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IF 3.2
Zhang Zhou,Wang Litao,Liang Hong,Chen Guanyu,Tao Huayu,Wu Jing,Gao Dawen
Polycyclic aromatic hydrocarbons (PAHs) are a class of persistent organic pollutants with carcinogenic, mutagenic and teratogenic effects. The white-rot fungi in the fungal group have significant degradation ability for high molecular weight organic pollutants. However, exogenous fungi are easily antagonized by indigenous microorganisms. Low molecular weight organic acids, a small molecular organic matter secreted by plants, can provide carbon sources for soil microorganisms. Combining organic acids with white rot fungi may improve the nutritional environment of fungi. In this study, immobilized Trametes versicolor was used to degrade benzo[a]pyrene in soil, and its effect on removing benzo[a]pyrene in soil mediated by different low molecular weight organic acids was investigated. The results showed that when the degradation was 35 days, the removal effect of the experimental group with citric acid was the best, reaching 43.7%. The degradation effect of Trametes versicolor on benzo[a]pyrene was further investigated in the liquid medium when citric acid was added, and the effects of citric acid on the biomass, extracellular protein concentration and laccase activity of Trametes versicolor were investigated by controlling different concentrations of citric acid. In general, citric acid can act as a carbon source for Trametes versicolor and promote its extracellular protein secretion and laccase activity, thereby accelerating the mineralization of benzo[a]pyrene by Trametes versicolor . Therefore, citric acid can be used as a biostimulant in the remediation of PAHs contaminated soil with Trametes versicolor .
研究领域:
环境科学
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微生物学
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产品关联
DOI
PubMed
高影响因子
CHEMOSPHERE
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2021
·
IF 7.086
Shunyao Li,Kai Sun
Humic constituents (HCs) are ubiquitous in the aquatic ecosystems , and contain various functional groups that seriously impact the conversion of 17 β -estradiol (17 β -E2) by fungal laccase. The purpose of this study was to explore the influencing mechanism of HCs on Trametes versicolor laccase-enabled 17 β -E2 oxidation and oligomerization. Herein, T. versicolor -secreted laccase could rapidly convert 99.2% of 17 β -E2 (rate constant = 3.7 × 10 −2 min −1 , half-life = 18.7 min) into multifarious oligomers at 25 °C and pH 5.0, by phenolic radical-caused C–C and/or C–O self-linking routes, whereas HCs with O -phenolic hydroxyl groups ( O -p-OH, i.e. , catechol, pyrogallol, gallic acid, and caffeic acid) dramatically suppressed 17 β -E2 oligomerization. Compared with HC-free, 17 β -E2 rate constants weakened 6.3–15.8 fold in the presence of HCs containing O -p-OH. It is largely because the O -p-OH was preferentially oxidized by T. versicolor laccase to create the electrophilic O -quinone monomers/oligomers. These unstable reactive O -quinone intermediates strongly reversed 17 β -E2 phenolic radicals to their monomeric molecules via two proton-transfer versus two electron-transfer channels, thus intercepting 17 β -E2 oxidation and oligomerization. These findings highlight new insights into the effect of HCs containing O -p-OH on T. versicolor laccase-started 17 β -E2 conversion, which is beneficial to re-understanding the fate and geochemical behavior of 17 β -E2 in water.
研究领域:
环境科学
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生物化学
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水生生态学
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酶学
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DOI
PubMed
高影响因子
FOOD AND BIOPRODUCTS PROCESSING
·
2021
·
IF 4.481
Peizhou Yang,Shuhua Lu,Wei Xiao,Zhi Zheng,Suwei Jiang,Shaotong Jiang,Shuying Jiang,Jieshun Cheng,Danfeng Zhang
Aflatoxin B 1 (AFB 1 ) is highly carcinogenic and teratogenic as a secondary metabolite of Aspergillus flavus and Aspergillus parasiticus . Trametes versicolor aflatoxin B 1 -degrading enzyme (TV-AFB 1 D) has capability of AFB 1 degradation. In this study, in order to improve the catalytic performance of TV-AFB 1 D, the molecular docking and site-directed mutagenesis techniques were applied to modify the key amino acid sites. Three mutation sites of Y305A, E436A, and H554A were selected for the directed mutation of TV-AFB 1 D. Four TV-AFB 1 D combinations of mutant H554A, Y305A/H554A, E436A/H554A, Y305A/E436A/H554A had potential to modify the catalytic performance according to the value of de-folding free energy. The TV-AFB 1 D mutations were expressed in engineering E. coli BL21 (DE3) with the size of approximately 77 kDa. The optimal temperature and pH value of TV-AFB 1 D were 32 °C and pH 7, respectively. E436A/H554A mutant represented the highest enzyme activities among these four mutants. The specific activity of E436A/H554A mutant (36 U/mg) was 1.84-fold in comparison with wild-type TV-AFB 1 D (19.6 U/mg) under the conditions of pH 7 and 32 °C. This study would contribute to the activity increase of TV-AFB 1 D by the performance improvement of AFB 1 degradation by site-directed mutagenesis approach.
研究领域:
酶学
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分子生物学
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食品安全
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微生物学
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DOI
高影响因子
HOLZFORSCHUNG
·
2022
·Vol. 76
·期 8
·732-743
·
IF 2.493
Zhenju Bi,Li Yan,Zhangjing Chen,Yafang Lei,Guangbin Li
The improvement of wood decay resistance is more inclined to eco-friendly methods such as the application of natural products, but the low durability of some natural products as wood preservatives limits their applications. In this study, vanillin catalyzed by laccase was grafted into poplar wood to increase wood decay resistance and can remain in wood for longer period. The reaction system of vanillin, ABTS, laccase and phosphate buffer solution was impregnated into poplar wood using vacuum-pressure method, and reacted at 40 °C for 6 h. Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), nuclear magnetic resonance (NMR) were used to confirm the grafting reaction actually occurring during the process. The decay resistance, leaching resistance and mechanical strength of grafted wood were evaluated. Energy-dispersive X-ray (EDX) mapping was used to characterize the vanillin distribution. The results indicated that vanillin grafted poplar wood had good decay resistance, leaching resistance and higher strength. The mass loss of grafted poplar wood exposed to white-rot fungi [ Trametes versicolor (L. ex Fr.) Quél.] and brown-rot fungi [ Gloeophyllum trabeum (Pers.: Fr.) Murr.] decreased from original 46 and 13% to 9 and 4%, respectively, even after leaching. The modulus of rupture (MOR) and modulus of elasticity (MOE) of the grafted poplar were 11 and 26% stronger than original poplar wood. Vanillin was found in wood cell wall. It was actually esterified onto wood catalyzed by the laccase.
研究领域:
材料科学
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化学
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林业
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生物技术
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产品关联
DOI
高影响因子
INDUSTRIAL CROPS AND PRODUCTS
·
2021
·
IF 5.645
Zhenju Bi,Yan Zhao,Jeffrey J. Morrell,Yafang Lei,Li Yan
Wood products are vulnerable to fungal degradation that reduces service life. Traditional wood preservatives can provide excellent service life but efforts are underway to develop more natural methods for wood protection. Konjac flying powder is a residual waste produced during the processing of corms of Konjac ( Amorphophallus konjac K. Koch) to produce Konjac flour. This waste material contains a number of compounds including salicylic acid (SA), 2,4,6-trichlorophenol (TCP), vanillin (VL), and cinnamaldehyde (CMA) has been found to be active against decay fungi; however, the antifungal mode of action is uncertain. The effects of konjac flying powder extract (KFPE) and its active compounds on cellulase, hemicellulose and ligninase activity, respiratory metabolism, cell membrane permeability, protein, and energy metabolism was studied on the white-rot fungus, Trametes versicolor (L. ex Fr.) Quél. ( T. versicolor ) and brown-rot fungus, Gloeophyllum trabeum (Pers.: Fr.) Murr. ( G. trabeum ). Konjac flying powder inhibited cellulase and hemicellulase activity of both fungi and ligninase activity of T. versicolor . Respiratory metabolism and energy metabolism were also inhibited. The four active compounds had different effects on activities suggesting that konjac flying powder functioned against multiple metabolic activities of the test fungi, potentially increasing its ability to provide broad spectrum wood protection.
研究领域:
植物学
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真菌化学
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木材科学
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真菌生物学
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）