JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
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2025
·
IF 6.2
Zehao Li,Wanying Wang,Lulu Zhang,Jinchu Yang,Yongming Xu,Zhenzhen Huang,Wanzeng Li,Shiying Wang,Jingwen Yang,Zhifeng Zhang
Dihydrocarvone is extensively utilized in food, pharmaceutical, and cosmetic fields because of its pleasant odor, high economic value, and diverse pharmacological properties. In this study, an ene reductase KlebER3, which catalyzed the conversion of carvone to dihydrocarvone using NAD(P)H as a cofactor, was identified from Klebsiella sp. O852 through genome sequencing. This enzyme displayed optimal activity at 30 °C and pH 7 and maintained appreciable stability at 20–50 °C and pH 6–8. Besides, KlebER3 had good resistance to dimethyl sulfoxide and glycerine and exhibited wide-ranging substrate acceptance for α,β-unsaturated compounds. Furthermore, a Q26A mutant with enhanced activity, stability, and stereoselectivity was obtained by molecular docking, alanine scanning, and site-directed mutagenesis. Molecular dynamics simulations revealed that these improvements may be attributed to increased nonpolar interactions, elevated flexibility of the active pocket, reduced binding free energy, and strengthened rigidity of protein conformation. This study established a basis for further investigations of the function and modification of ene reductase as well as the efficient biosynthesis of dihydrocarvone.
研究领域:
酶学
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生物催化
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微生物生物技术
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分子生物学
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计算生物学
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高影响因子
WATER RESEARCH
·
2025
·
IF 12.4
Bobo Xing,Ji Li,Linlin Li,Nigel J.D. Graham,Xian Li,Wenzheng Yu
Excessive accumulation of nitrate in natural ecosystems can lead to eutrophication of water bodies, resulting in environmental impacts such as algal blooms and red tides that pose serious threats to environmental and human health. Autotrophic denitrification is a resource-efficient biological nitrogen removal technology, but the slow growth and low electron transfer efficiency of autotrophic denitrifiers limit their practical application. In this study, the heterotrophic denitrifying bacterium Pseudomonas sp. JM-7 ( P. JM-7) was used in mixed culture with the autotrophic denitrifying Thiobacillus denitrificans ATCC 25259 to form a heterotrophic-autotrophic synergistic denitrification process (mixPT) to enhance electron transfer and improve the denitrification efficiency. Our results for an initial nitrate concentration of 430 mg/L showed that P. JM-7 reduced approximately 210 mg/L nitrate (48.8 %) in 90 h, with 1 g/L yeast extract powder (YEP) as the electron donor, while Thiobacillus denitrificans barely removed nitrate. In contrast, the mixPT system reduced approximately 360 mg/L nitrate (83.3 %), nearly 1.7 times greater than P. JM-7 alone. The mixPT culture also exhibited excellent denitrification in low carbon waters (10 mg/L), and removed 40 mg/L nitrate completely within 120 h. Cytochrome c produced by Pseudomonas sp. JM-7, which is an excellent electron transfer mediator for denitrification by Thiobacillus denitrificans , played a crucial role in the heterotrophic-autotrophic syntrophic denitrification. The adsorption effect of Pseudomonas sp. JM-7 shortened the contact distance between the autotrophic denitrifying bacteria and cytochrome c, which made it easy for cytochrome c to transfer the electrons to the autotrophic bacteria directly, thereby reducing the loss of electrons in the process of transfer, and improved the electron utilization efficiency. These findings have demonstrated the potential applications of mixPT system in controlling eutrophic waters and propose cytochrome c of Pseudomonas sp. JM-7 could serve as a novel and high-quality electron transfer mediator. Furthermore, this study have overcome the restriction of low denitrification efficiency exhibited by heterotrophic denitrifying bacteria Pseudomonas sp. JM-7 in low-carbon environments and expanded the utilisation of Pseudomonas sp. JM-7 in low carbon environments.
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Toxics
·
2025
·Vol. 13
·期 11
·946
·
IF 4.1
Jin Liu,Yankun Zhang,Fengyuan Chen,Dandan Duan,Xiaoping Diao
In the environment, the coexistence of microplastics (MPs) with other pollutants may either enhance or reduce the toxicity of MPs themselves or the co-occurring pollutants toward microalgae. This phenomenon is particularly notable when MPs interact with emerging pollutants, such as ultraviolet absorbers. This study investigates the single and combined exposure effects of ultraviolet absorber (Butyl methoxydibenzoylmethane, BMDM, 50 μg/L) and MPs (Polystyrene, PS, 10 mg/L, d = 1 μm) onChlorellasp. with a stress duration of 7 days. The results showed that cell density, chlorophyll a (Chla) concentration, and physical properties of cell surface integrity were higher in the combined stress group compared to the BMDM single stress group. Furthermore, transcriptome sequencing analysis revealed that the number of differentially expressed genes (DEGs) in the combined exposure group (885 DEGs) was lower than in the single exposure groups (BMDM: 1870 DEGs and PS: 9109 DEGs). Transcriptomic profiling indicated that individual stressors of BMDM and PS disrupted 113 and 123 pathways, respectively, predominantly associated with protein synthesis and energy metabolism. Conversely, combined exposure significantly enriched 86 pathways, including ribosome function and oxidative phosphorylation, thereby manifesting an antagonistic effect. This study provides new insights into the effects of BMDM and PS onChlorellasp. and offers valuable information for the risk assessment of multiple pollutants.
研究领域:
环境毒理学
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藻类学
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生态毒理学
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转录组学
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海洋污染
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高影响因子
Journal of Environmental Chemical Engineering
·
2025
·
IF 7.2
Xiaoxian Cai,Ke Chen,Lixue Zheng,Huijun Guan,Tianlong Hao,Wenqing Zhou,Jingjing Yang,Lihua Qi,Chunfeng Guan
The widespread accumulation of organic pollutants in agricultural soils, such as dimethyl phthalate (DMP), poses serious risks to human health and ecological safety. The application of plant growth-promoting rhizobacteria (PGPR) to improve phytoremediation efficiency for organic pollutant-contaminated soils has gained increasing attention. However, synergistic PGPR-plant signaling and competitive root colonization of PGPR directly affect the remedial efficiency of the PGPR-plant system for soil organic pollutants. Acyl-homoserine lactones (AHLs), one of the quorum sensing (QS) signals, can enhance microbial cooperation and promote plant growth, thereby probably facilitating phytoremediation processes for pollutant degradation. In this study, the potential capacity of AHLs to assist PGPR in the phytoremediation of DMP-polluted soils was explored, with a focus on their effects on DMP removal, plant physiological functions, and rhizosphere microbial community structure. The results showed that AHLs (C 4 -HSL)-assisted PGPR ( Bacillus YT2) treatment significantly increased DMP removal to 92.60 % and improved plant growth. Compared to the individual AHLs or PGPR treatments, the AHLs-assisted PGPR more effectively enhanced plant photosynthesis, osmoregulation, and antioxidant capacity, reduced oxidative damage, and improved soil enzyme activity and nutrient availability. Additionally, the AHLs-assisted PGPR treatment modulated microbial community in the rhizosphere, increasing the richness of pivotal functional taxa such as Xanthomonadaceae and Acidobacteriota. AHLs might directly promote DMP degradation by regulating the QS system and enhancing plant-bacterial communication, while also indirectly supporting plant growth through stress tolerance enhancement. In conclusion, AHLs-mediated enhancement of PGPR functionality provides a promising approach for remediating DMP-contaminated soils and offers a theoretical basis for developing composite microbial formulations.
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BIORESOURCE TECHNOLOGY
·
2025
·
IF 9
Juping You,Yanqing Wang,Feng Gao,Yaxue He,Jiexu Ye,Jingkai Zhao,Dongzhi Chen
The biofixation of carbon dioxide (CO 2 ) by chemoautotrophic microorganisms has garnered substantial research attention. Zero-valent iron has been considered an outstanding electron donor, however, studies on iron-driven CO 2 biofixation remain limited. Brucella sp. WYQ-2 was firstly time isolated and demonstrated efficient CO 2 fixation at rate of 4.7 g/(m 3 ·d) using iron as sole electron donor. The optimal culture conditions were 80 g/m 3 CO 2 , 1 g iron, and a neutral pH, the tolerated CO 2 concentration was up to 130 g/m 3 (66 % v/v). Furthermore, more than 95 % of CO 2 was converted to biomass and organic compounds (methane, acetate, and cyclobutanol), and the acetate yield was 36.4 mg/L. Transcriptomic analyses further revealed that three CO 2 bioconversion pathways of Wood-Ljungdahl pathway, C4-dicarboxylic acid cycle, and reductive tricarboxylic acid cycle were involved. Overall, this study enriched the species of CO 2 reduction and provided a promising candidate for CO 2 biofixation in future full-scale applications.
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ACS Omega
·
2025
·
IF 4.3
Songzhi Li,Yang Guo,Hong Jiang,Huan Zhang,Jiayu Li,Yanli Chen,Jie Li,Xiangzhao Mao,Minxiao Wang
Arylsulfatase catalyzes the cleavage of sulfate ester bonds and plays a role in agar desulfation, thereby enhancing agar gel strength and quality. While studying the desulfurization pathway in Pseudoalteromonassp. SR43-6, a sequence encoding a potential arylsulfatase─Pseudoalteromonas Ars (Ps-Ars)─was found. The enzyme, with p-nitrophenyl sulfate as a substrate, exhibited optimal activity at 35 °C and pH 8.0. Its relative activity (206 U/mg) exceeded that of the recently identified arylsulfatases. Four hundred units of the enzyme removed 86.4% of sulfate groups from Gelidium amansii agar in 4 h, whereas 800 U of the enzyme removed 71.3% of sulfate groups from Gracilaria lemaneiformis agar in 8 h. After enzymatic treatment, G. amansii agar gel strength was enhanced by 32%, and a similar improvement was observed in G. lemaneiformis agar gel strength. Enzymatic agar desulfurization offers mild, quality-retaining, and environmentally friendly advantages, augmenting industrial application prospects.
研究领域:
生物化学
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海洋微生物学
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食品科学
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高影响因子
BIORESOURCE TECHNOLOGY
·
2026
·
IF 9
Junhua Di,Yizhen Zhang,Bright Uwse,Paul Arnaud Yao Koffi,Yu-Cai He,Cuiluan Ma
To enhance the application potential of ω-transaminase ATA1012 in the efficient bioamination of biobased aldehydes, this study performed site-directed mutagenesis at key sites in the active center and flexible loop region, resulting in the mutant Q25F with significantly improved thermostability. The half-life of Q25F increased from 4.2 h to 25.1 h at 37 °C and from 0.6 h to 3.3 h at 50 °C. Benefiting from its enhanced stability, Q25F efficiently converted lignin-derived vanillin (260 mM) to vanillylamine within 12 h, achieving a yield of 92.6% and a selectivity >99%. Kinetic analysis revealed a Km of 0.2 mM for vanillin, a kcat of 8.9 s −1 , and a catalytic efficiency (kcat/Km) of 33.1 M −1 s −1 . Furthermore, by optimizing the mutagenesis strategy, engineered strains capable of efficiently catalyzing the transamination of biomass-derived furfural (FAL) and 5-hydroxymethylfurfural (HMF) into biobased amines were constructed. This study establishes a site-directed mutagenesis approach for enhancing the thermostability of ω-transaminase, providing an effective route for the high-value bioconversion of carbohydrates and lignin in lignocellulosic biomass.
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高影响因子
BIOTECHNOLOGY LETTERS
·
2013
·Vol. 36
·期 2
·341-347
·
IF 1.853
He Yu-Cai,Wu Ya-Dong,Pan Xue-He,Ma Cui-Luan
The nitrilase from Rhodococcus sp. CCZU10-1 catalyses the hydrolysis of dinitriles to acids without the formation of amides and cyanocarboxylic acids. It was induced by benzonitrile and its analogues (tetrachloroterephthalonitrile > ε-caprolactam > benzonitrile > phenylacetonitrile), and had activity towards aromatic nitriles (terephthalonitrile > tetrachloroterephthalonitrile > isophthalonitrile > tetrachloroisophthalonitrile > tetrafluoroterephthalonitrile > benzonitrile). After the optimization, the highest nitrilase induction [311 U/(g DCW)] was achieved with tetrachloroterephthalonitrile (1 mM) in the medium after 24 h at 30 °C after optimum enzyme activity was at pH 6.8 and at 30 °C. Efficient biocatalyst recycling was achieved by cell immobilization in calcium alginate, with a product-to-biocatalyst ratios of 776 g terephthalic acid/g DCW and 630 g isophthalic acid/g DCW.
研究领域:
生物化学
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生物催化
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微生物生物技术
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工业微生物学
·
绿色化学
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高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
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2026
·
IF 6.7
Lijuan Meng,Wenwen Zhang,Guoyan Mo,Yu Gao,Lu Cao,Huabing Yang,Tianxiang Zhu,Lei Xiong,Hongtao Liu
Xyloglucan oligosaccharides (XyGOs) are emerging prebiotics with limited sustainable production strategies. Here, two endoxyloglucanases, XyGH5 and XyGH74, from the bacterium Paenibacillus sp. XP01 were identified. Genetic knockout revealed their synergistic role in bacterial growth on xyloglucan. Biochemical characterization showed that XyGH74 exhibited superior activity (Vmax = 76.25 U/mg) and thermal stability (optimum at 70 °C) compared to XyGH5, with its carbohydrate-binding modules (CBMs) crucially enhancing catalytic efficiency and substrate affinity. We further employed the highly efficient XyGH74 to produce tamarind xyloglucan oligosaccharides (TXOS). In vitro fermentation with human gut microbiota demonstrated that TXOS significantly modulated microbial composition, enriching beneficial genera such as Bacteroides and Parabacteroides, and notably enhanced the production of short-chain fatty acids, particularly butyrate, compared to the native polysaccharide. This study provides direct genetic evidence for synergistic glycoside hydrolase function in vivo and establishes XyGH74 as a robust enzymatic tool for scalable, high-value prebiotic production with enhanced health benefits.
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FEMS MICROBIOLOGY LETTERS
·
2026
·
IF 2
Qian Shunyi,Wang Huayi,Liu Yuqian,Ding Jiapeng,Zhang Yue,Zhang Ziqiu,Deng Zifa,Zhou Yidong
Metronidazole is a widely used nitroimidazole antibiotic in clinical practice. Following its widespread use, it enters the environment via medical wastewater, posing a potential risk of toxicity to ecosystems and living organisms. Microbial degradation is an efficient method of accurately eliminating target pollutants from the environment. Here, a metronidazole degrader, Sphingopyxis sp. K5, was isolated from medical wastewater sludge. Strain K5 could degrade 58.7 μM metronidazole after 4 days of incubation with an initial OD600 of 1.5. The optimal degradation conditions were 35°C and pH 8.0, and the strain exhibited stable degradation efficiency on high metronidazole concentrations (100-500 μM). The supplementation of nutrients such as LB or glucose can improve degradation efficiency by 152.0% and 129.0%, respectively. Design-Expert software was used for optimization of conditions such as temperature (33.7°C), pH (8.2), and cell density of inoculation (OD600 of 1.0). The degradation of metronidazole in soil and wastewater by strain K5 proved its potential for application. Strain K5 could eliminate > 95% of 5 and 25 ppm metronidazole in soil and wastewater within 5 and 10 days, respectively. Our results characterized the degradation efficiency of metronidazole by strain K5 and provided a theoretical basis for the bioremediation of metronidazole-contaminated environments.
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CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Aonan Qiao,Yu Liu,Fei Li,Haixia Pan,Yanan Guo,Yang Liu,Xianliang Yi,Hao Zhou
Manganese-oxidizing bacteria (MnOB) mediate the oxidation of Mn(II) in both natural and engineered environments. Although numerous MnOB have been isolated, the regulatory mechanisms governing their Mn(II)-oxidizing activity in response to nitrogen sources remain poorly understood. This study investigates how nitrogen sources affect the Mn(II)-oxidizing capability of Pseudomonas sp. AN-1. Mn(II) oxidation was completely inhibited in NH 4 + -supplemented cultures, with no detectable BioMnOx production throughout a 10-day incubation period. In contrast, complete oxidation of 100 μM Mn(II) occurred within 27 h when either NO 3 − or NO 2 − as the nitrogen source. Intriguingly, Mn(II) oxidation exhibited a histidine concentration-dependent pattern: no oxidation was observed at 0.5–1.0 mM histidine, whereas complete oxidation occurred at 2.5 mM. Transcriptomics and proteomics revealed NO 3 − -fed cultures exhibited significantly higher expression of manganese oxidation genes, including mnxG and mcoA , compared to histidine-supplemented cultures. Further analysis identified the MnxS/MnxR as essential for initiating the transcription of mnxG and mcoA . Bioinformatic analysis revealed this regulatory system is widely distributed in the genus Pseudomonas and frequently co-occurs with mnxG and mcoA . This study provides insight into nitrogen-source dependent regulation of bacterial Mn(II) oxidation, uncovering concentration-dependent effects and identifying the MnxS/MnxR system as a key regulatory node that integrates nitrogen sensing with Mn(II) oxidation.
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MOLECULAR PLANT-MICROBE INTERACTIONS
·
2024
·
IF 3.2
Yanning Tian,Fangya Zhong,Na Shang,Houyu Yu,Dongmei Mao,Xing Huang
Diphenyl ether herbicides are extensively utilized in agricultural systems, but their residues threaten the health of sensitive rotation crops. Functional microbial strains can degrade diphenyl ether herbicides in the rhizosphere of crops, facilitating the restoration of a healthy agricultural environment. However, the interplay between microorganisms and plants in diphenyl ether herbicides degradation remains unclear. Thus, the herbicide-degrading strain Bacillus sp. Za and the sensitive crop, maize, were employed to uncover the interaction mechanism. The degradation of diphenyl ether herbicides by strain Bacillus sp. Za was promoted by root exudates. The strain induced root exudates re-secretion in diphenyl ether herbicide-polluted maize. We further showed that root exudates enhanced the rhizosphere colonization and the biofilm biomass of strain Za, augmenting its capacity to degrade diphenyl ether herbicide. Root exudates regulated gene fliZ, pivotal in biofilm formation. Wild-type strain Za significantly reduced herbicide toxicity to maize compared to the ZaΔfliZ mutant. Moreover, root exudates promoted strain Za growth and chemotaxis, which was related to biofilm formation. This mutualistic relationship between the microorganisms and the plants demonstrates the significance of plant-microbe interactions in shaping diphenyl ether herbicide degradation in rhizosphere soils.
研究领域:
环境微生物学
·
植物科学
·
农业化学
·
微生物生态学
·
生物修复
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高影响因子
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