Synthetic and Systems Biotechnology
·
2024
·
IF 4.4
Haixia Wang,Jiahong Zhu,Meng Sun,Mengjie Gu,Xiya Xie,Tongtong Ying,Zeling Zhang,Weihong Zhong
The waste pollution problem caused by polyethylene terephthalate (PET) plastics poses a huge threat to the environment and human health. As plasticizers, Phthalate esters (PAEs) are widely used in PET production and become combined pollutants with PET. Synthetic biology make it possible to construct engineered cells for microbial degradation of combined pollutants of PET and PAEs. PET hydroxylase (PETase) and monohydroxyethyl terephthalate hydroxylase (MHETase) isolated from Ideonella sakaiensis 201-F6 exhibit the capability to depolymerize PET. However, PET cannot enter cells, thus enzymatic degradation or cell surface displaying technology of PET hydrolase are the potential strategies. In this study, Pseudomonas sp. JY-Q was selected as a chassis strain, which exhibits robust stress tolerance. First, a truncated endogenous outer membrane protein cOmpA and its variant Signal (OprF)-cOmpA were selected as anchor motifs for exogenous protein to display on the cell surface. These anchor motifs were fused at the N-terminal of PET hydrolase and MHETase and transformed into Pseudomonas sp. JY-Q, the mutant strains successfully display the enzymes on cell surface, after verification by green fluorescent protein labeling and indirect immunofluorescence assay. The resultant strains also showed the catalytic activity of co-displaying PETase and MHETase for PET biodegradation. Then, the cell surface displaying PET degradation module was introduced to a JY-Q strain which genome was integrated with PAEs degrading enzymes and exhibited PAEs degradation ability. The resultant strain JY-Q-R1-R4-SFM-TPH have the ability of degradation PET and PAEs simultaneously. This study provided a promising strain resource for PET and PAEs pollution control.
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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.
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EUROPEAN POLYMER JOURNAL
·
2024
·
IF 5.8
Kun Liu,Yawen Fu,Qiqi Dai,Haoyun Tan,Zhuowei Gu,Qiaoqiao Xiong,Shuai Yang,Mingming Zhang,Jianxiang Feng,Wenjun Yi,Lijun Li
Pure multi-block copolymers and deformed multi-block copolymers have unique applications in the field of high-performance thermoplastic elastomers, resins and rubber materials. For styrene ( S ) and conjugated 1,3-dienes ( e.g. 1,3-pentadiene, P ) monomers, living anionic polymerization ( LAP ) has significant advantages in precise control of molecular weight and its distribution and precise control of microstructure and the sequence distribution. Subsequently, the post-polymerization modification strategy including epoxidation can further expand the application field of such polymer materials. Herein, a series of novel symmetrical triblock copolymers of different compositions with homo-polystyrene as end-blocks and strictly alternating sequence as mid-block, poly( S )- b -poly( S - alt - P )- b -poly( S ) ( SSPS ), were synthesized in cyclohexane by the classical three-step sequential feeding method using n -BuLi as initiator. The effect of the block ratio of SSPS triblock copolymer on impact strength, flexural strength and yield strength of transparent resin products was studied in detail. In addition, quantitative epoxidation post-polymerization functional modification was performed to obtain the novel triblock copolymer product which had a high-polarity and high-transparent thermoplastic resin with well-defined structure and quantitative degree of epoxidation ( ED ). All these novel copolymers before and after modification were characterized by 1 H NMR, 13 C NMR, FTIR, DSC and GPC.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2025
·
IF 8.5
Alei Zhang,Runke Wang,Xi Zhou,Quanzhen Liu,Xin Zhang,Feifei Chen,Kequan Chen
In this work, a GH18 chitinase (Chi1) with highly hydrolytic activity was identified from Chitinibacter sp. GC72 and successfully cloned and expressed in Escherichia coli BL21(DE3). The recombinant Chi1 exhibited specific activities of 362.6 U/mg against colloidal chitin and 56.7 U/mg against raw α-chitin. Analysis of hydrolysis pattern showed that Chi1 is a multifunctional chitinase, which mainly exhibited processive exo-acting activity with some endo-acting and N -acetyl glucosaminidase activities. Structural analysis and molecular docking were conducted to explore the potential mechanism underlying the highly and multiple activities. Furthermore, Chi1 was utilized to convert raw α-chitin into reducing sugar affording 48.6% ( w / w ) yield of total sugar with a 1:4 molar ratio of NAG to NAG 2 , while also displaying hydrolysis activity to chitinous biomass with 4.1% sugar yield. This study provides a potent chitinase to hydrolyze chitinous resource with unusual product pattern, showing great potential for further industrial applications.
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APPLIED AND ENVIRONMENTAL MICROBIOLOGY
·
2017
·Vol. 83
·期 10
·
IF 3.807
Yaojie Gao,Gudan Xu,Pan Wu,Jin Liu,You-sheng Cai,Zixin Deng,Wenqing Chen
2′-Chloropentostatin (2′-Cl PTN, 2′-chloro-2′-deoxycoformycin) and 2′-amino-2′-deoxyadenosine (2′-amino dA) are two adenosine-derived nucleoside antibiotics coproduced by Actinomadura sp. strain ATCC 39365. 2′-Cl PTN is a potent adenosine deaminase (ADA) inhibitor featuring an intriguing 1,3-diazepine ring, as well as a chlorination at C-2′ of ribose, and 2′-amino dA is an adenosine analog showing bioactivity against RNA-type virus infection. However, the biosynthetic logic of them has remained poorly understood. Here, we report the identification of a single gene cluster (ada) essential for the biosynthesis of 2′-Cl PTN and 2′-amino dA. Further systematic genetic investigations suggest that 2′-Cl PTN and 2′-amino dA are biosynthesized by independent pathways. Moreover, we provide evidence that a predicted cation/H+ antiporter, AdaE, is involved in the chlorination step during 2′-Cl PTN biosynthesis. Notably, we demonstrate that 2′-amino dA biosynthesis is initiated by a Nudix hydrolase, AdaJ, catalyzing the hydrolysis of ATP. Finally, we reveal that the host ADA (designated ADA1), capable of converting adenosine/2′-amino dA to inosine/2′-amino dI, is not very sensitive to the powerful ADA inhibitor pentostatin. These findings provide a basis for the further rational pathway engineering of 2′-Cl PTN and 2′-amino dA production.IMPORTANCE 2′-Cl PTN/PTN and 2′-amino dA have captivated the great interests of scientists, owing to their unusual chemical structures and remarkable bioactivities. However, the precise logic for their biosynthesis has been elusive for decades. Actually, the identification and elucidation of their biosynthetic pathways not only enrich the biochemical repertoire of novel enzymatic reactions but may also lay solid foundations for the pathway engineering and combinatorial biosynthesis of this family of purine nucleoside antibiotics to generate novel hybrid analogs with improved features.
研究领域:
微生物学
·
分子生物学
·
药物化学
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ARCHIVES OF MICROBIOLOGY
·
2022
·Vol. 204
·期 3
·1-14
·
IF 2.667
Chen Sha,Ding Zhexu,Chen Jinyuan,Luo Jun,Ruan Xiaofang,Li Zongpei,Liao Fengfeng,He Jing,Li Ding
Bacterial non-enzymatic Mn(II) oxidation involving reactive oxygen species (ROS) (i.e., indirect oxidation), initially discovered from a marine alpha-proteobacterium, is believed to be of importance in controlling biogeochemical cycles. For soil-borne bacteria, however, evidence of indirect Mn(II) oxidation remains unclear. In this study, the indirect Mn(II) oxidation was evidenced in a soil-borne bacterium, Providencia sp. LLDRA6. First, with and without 50 mM of Mn(II) exposure for LLDRA6, 300 differentially expressed genes were found to be linked to Mn(II) exposure via transcriptome sequencing. Among them, an operon, responsible for phenylacetic acid catabolism, was sharply upregulated in transcription, drawing us a special attention, since its transcriptional upregulation has recently shown to be important for withstanding ROS. Next, a fluorometric probe, 2′,7′-Dichlorofluorescin diacetate (DCFDA), was used to qualitatively detect ROS from cells, showing a distinct increase in fluorescence intensities of ROS during Mn(II) exposure. Furthermore, concentrations of superoxide and hydrogen peroxide from cells were detected, respectively, with and without Mn(II) exposure, exhibiting that when Mn(II) oxidation occurred, superoxide concentration significantly increased but hydrogen peroxide concentration significantly decreased. Particularly, superoxide produced by LLDRA6 was proven to be the oxidant for Mn(II) in the formation of Mn oxides. Finally, we predicted links between phenylacetic acid metabolism pathway and ROS during Mn(II) exposure, proposing that the excessive ROS, generated in response to Mn(II) exposure, transcriptionally activate phenylacetic acid catabolism presumably by increasing concentrations of highly reactive oxepins.
研究领域:
微生物学
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环境科学
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生物地球化学
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Microorganisms
·
2026
·Vol. 14
·期 5
·993
·
IF 4.7
Yuwei Xing,Jingru Zhang,Cong Liu,Yang Liu,Jun Wang
Nymphaea candida Presl is a rare and endangered waterlily species, and cultivating robust seedlings suitable for artificial propagation has become a critical issue for the conservation of this species. In this study, Aspergillus sp., an endophytic fungus isolated from the roots of N. candida , showed the capability of solubilizing phosphate and potassium and producing siderophores. The application of Aspergillus sp. significantly increased leaf length, leaf width, leaf number, and root length of N. candida seedlings by 97.83%, 131.37%, 94.12%, and 171.25%, respectively. Meanwhile, Aspergillus sp. application significantly enhanced soil organic matter content, alkali-hydrolyzable nitrogen content, sucrase activity, and peroxidase activity by 6.57%, 31.62%, 23.26%, and 7.53%, respectively. Moreover, Aspergillus sp. enriched beneficial microorganisms including Cyanobium , Aquicella , and Cryptomycota to form a more stable rhizosphere soil microenvironment. Additionally, Aspergillus sp. upregulated genes involved in photosynthesis and photosynthesis–antenna protein pathways in N. candida leaves, with the expression levels of psbA , petG , and psbH significantly increasing by 2.17, 4.48, and 0.28-fold, respectively. Therefore, the endophytic fungus Aspergillus sp. might be a reliable tool for the propagation of N. candida seedlings, which would be helpful for the conservation of this rare and endangered aquatic plant species.
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INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2023
·
IF 7.2
Minglei Lu,Shuting Liu,Haiping Zhu,Haifeng Huang,Chunying Lin,Jianxian Li,Baofang Zhang,Zefeng Zheng,Changsong Hu,Xiaoping Wu,Geli Liu,Tiejun Wang
Highly efficient releasing of hydrogen by aqueous-phase reforming of methanol (APRM) is of great significance to promote the development of stationary and mobile H 2 power supply for polymer electrolyte membrane fuel cells (PEMFCs). However, highly active catalysts with excellent performance of in situ releasing H 2 from APRM still face challenges. Herein, we report a Cu-SP/Al 2 O 3 –ZnO (Cu-SP/AZ) catalyst prepared by carbon layer encapsulated hierarchical porous microsphere strategy, which enhanced Cu dispersion (52.8 wt% loading, ∼5 nm particle size) on Al 2 O 3 –ZnO (AZ) microsphere . The proposed catalyst exhibited high H 2 production rate (base-free) of 64.23 μmolH 2 /gcat/s at 210 °C, which was nearly the same as that of 20% Pt/C catalyst (63.86 μmolH 2 /gcat/s) and 2.6-fold higher than that of commercial CuO/ZnO/Al 2 O 3 catalyst (24.62 μmolH 2 /gcat/s). The characterization results demonstrated that its high activity in APRM could be ascribed to the strategy of carbon layer encapsulated hierarchical porous microsphere as well as coordination of hydroxyl functional group of SP with Cu 2+ .
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RSC Advances
·
2023
·Vol. 13
·期 27
·18878-18887
·
IF 3.9
Jingnan Jin,Yahui Shi,Baozhong Zhang,Dongjin Wan,Qingye Zhang,Ying Li
Owing to its adverse effects on the environment and human health, benzo[a]pyrene (BaP) has attracted considerable attention and has been used as a model compound in ecotoxicology. In this study, Pannonibacter sp. JPA3 as a BaP-degrading strain was isolated from the production water of an oil well. The strain could remove 80% of BaP at an initial concentration of 100 mg L−1 after 35 d culture. The BaP-4,5-dihydrodiol, BaP-4,5-epoxide, 5-hydroxychrysene, and 2-hydroxy-1-naphthoic acid metabolites were identified in the biodegradation process. Simultaneously, the gene sequence coding for dioxygenase in the strain was amplified and a dioxygenase model was built by homology modeling. Combined with the identification of the metabolites, the interaction mechanism of BaP with dioxygenase was investigated using molecular docking. It was assumed that BaP was initially oxidized at the C4–C5 positions in the active cavity of dioxygenase. Moreover, a hypothesis for the progressive degradation mechanism of BaP by this strain was proposed via the identification of the downstream metabolites. In conclusion, our study provided an efficient BaP degrader and a comprehensive reference for the study of the degradation mechanism in terms of the degrading metabolites and theoretical research at the molecular level.
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BIORESOURCE TECHNOLOGY
·
2024
·
IF 9.7
Yizhen Zhang,Yu-Cai He,Cuiluan Ma
Lignin is a plentiful and readily accessible renewable resource. Vanillylamine is a crucial raw material used to synthesize pharmaceuticals and high-value furan compounds that can be acquired by aminating lignin-derived vanillin (Van). However, effectually achieving the biocatalytic synthesis of vanillylamine has remained challenging. In this study, a dimethyl sulfoxide (DMSO)-H 2 O (1:9, vol/vol) bioreaction medium was constructed, and a recombinant E. coli ATA1012 carrying ω-transaminase from Caulobacter sp. D5 was used as the ω-transaminase biocatalyst to acquire the effectual biocatalytic synthesis of vanillylamine. Under optimized bioreaction conditions (37 ℃ and pH 7.5) by supplementary of isopropylamine (IPA) (Van/IPA = 1:5, mol/mol), 80–100 mM Van could be effectually converted by ATA1012 whole cells in DMSO-H 2 O (1:9, vol/vol) within 12 h, yielding 91.2 %–95.4 % vanillylamine, with >99 % selectivity. An efficient amination process was developed using ATA1012 with superior transaminase catalytic activity and substrate tolerance to effectively convert Van to vanillylamine in a DMSO-H 2 O medium.
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Journal of Water Process Engineering
·
2025
·
IF 6.7
Kang Zhichao,Wang Tianye,Nannan Li,Han Xuerong,Wang Chenxu,Yang Xiutao,Jing Yue,Yu Hongwen
The leaching of atrazine wastes from agricultural areas presents a considerable risk to the ecosystem. This work aims to create microorganism-material systems employing the atrazine-degrading strain Paenarthrobacter sp. KN0901 and C 3 N 5 -based materials to efficiently eliminate atrazine residues from aquatic environments at low temperatures. The synthesized C 3 N 5 and O-C 3 N 5 markedly improved the growth and atrazine degradation of KN0901. The degradation rate of atrazine in the KN0901-C 3 N 5 and KN0901-O-C 3 N 5 systems rose by 7.3 % and 15.1 %, respectively, in comparison to biodegradation systems. The elevated NADH/NAD+ and GSH/GSSG ratios indicated a greater availability of electrons to KN0901 when associated with C3N5-based materials, implying that these materials contributed electrons to KN0901. Nitazoxanide and methyl viologen inhibited the electron transfer route, leading to a significant decrease in the breakdown rate of KN0901-C 3 N 5 systems. Glucose and sodium citrate, functioning as electron donors, markedly accelerated the degradation rate of atrazine in the KN0901-C 3 N 5 systems. This work demonstrated that C 3 N 5 -based materials may donate electrons to KN0901, hence improving the efficiency of atrazine breakdown at low temperatures. This work successfully developed microorganism-material systems that effectively eliminate atrazine in aquatic settings, especially in cold climates.
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FOOD RESEARCH INTERNATIONAL
·
2025
·
IF 8
Junde Ren,Feifei Hu,Farooq Muhammad,Lihui Hu,Tao Song,Maninder Meenu,Jie Lin,Ying Liu,Hosahalli S. Ramaswamy,Yong Yu
This study investigated the freezing characteristics of Arctic yeast Leucosporidium sp. AY30 ice-binding protein (LeIBP) after heterologous expression by Aspergillus niger at different concentrations (0.01 %, 0.05 %, 0.1 %, 0.2 %, 0.5 %) and elucidated its effects on physicochemical quality, myofibrillar protein (MP) and ice crystal morphology of largemouth bass during air freezing. LeIBP achieved ice crystal regulation by significantly reducing the freezing point, super-cooling degree and phase transition time of the aqueous solution and prolonging the time of the maximum ice crystal formation zone (−1 to −5 °C). Its thermal hysteresis activity (THA) reached a peak at 0.2 % concentration (1.36 °C), which was superior to the THA of most traditional AFPs. Notably, the addition of 0.05 %LeIBP dramatically reduced the cross-sectional area and mean diameter of ice crystals by up to 91 % and 70 %, respectively. In addition, the addition of LeIBP better maintained the texture of fish, led to an increase in the L* value and a decrease in the b* value, and inhibited the decrease in the a* value, but decreased its water holding capacity slightly. Meanwhile, the addition of 0.01 %LeIBP better inhibited the reduction of MP content and maintained the stability of MP tertiary structure. The addition of LeIBP increased the α-helix content by 1.0–6.9 % to maintain the MP secondary structure, also significantly increased the ion bond content, hydrogen bond content, and hydrophobic interactions. In summary, the addition of low concentration (0.01 % and 0.05 %) of LeIBP better maintained the quality of fish meat during air freezing.
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