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Rational protein engineering of thermostable heparinase I from Bacteroides thetaiotaomicron for highly efficient heparin degradation

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Food Science and Human Wellness 2024年

作者： Chuan Zhang Ruohan Zhao Leilei Yu Qixiao Zhai Jianxin Zhao Hao Zhang xuegang luo Fengwei Tian Wei Chen State Key Laboratory of Food Science and Technology， Jiangnan University School of Food Science and Technology， Jiangnan University Key Laboratory of Industrial Fermentation Microbiology of the Ministry of Education & Tianjin Key Lab of Industrial Microbiology， College of Biotechnology， Tianjin University of Science and Technology National Engineering Research Center for Functional Food， Jiangnan University

Heparin， a glycosaminoglycan， is a stable source of carbon that supports the growth of microorganisms in the human intestine. It is also a commonly used anticoagulant drug in clinical practice， with significant therapeutic effects. Low molecular weight heparin （LMWH） is a highly active low molecular weight fragment obtained via enzymatic reaction or the chemical degradation of heparin. LMWH has been applied globally in the prevention and treatment of venous thromboembolism in thrombosis patients. Simultaneously， as a potential prebiotic， because of its low molecular weight， LMWH can be well degraded by the gut microbiota to maintain intestinal balance. Enzymatic heparin degradation has recently emerged as a viable disposal method for LMWH preparation; however， only very few benchmark enzymes have been thoroughly described and subjected to protein engineering to improve their properties over the past few years. The commercialization of enzymes will require the development of robustly engineered enzymes that meet the demands of industrial processes. Herein， we report a rational protein engineering strategy that includes molecular dynamic simulations of flexible amino acid mutations and disulfide bond screening. Several Bt-HepI mutants were obtained and screened for high thermal stability. We obtained the Bt-HepID204C/K208C/H189W/Q198Rvariant， which features a stabilized protein surface structure， with a 1.3-fold increase in kcat/Km， a 2.44-fold increase in thermal stability at 50℃， and a 1.8-fold decrease in the average molecular weight of LMWH produced at 40℃ compared with that seen with Bt-HepIWT. Our study establishes a strategy to engineer thermostable HepI to underpin its industrial applications.

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Sorption of Pb(II) from aqueous solution by konjac glucomannan beads

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Science China(Technological Sciences) 2009年第1期52卷 223-226页

作者： LONG XiaoYan luo xuegang WANG Yang LI Zheng School of Life Science and Engineering Southwest University of Science and TechnologyMianyang 621000China China Academy of Engineering Physics Mianyang 621000China

Konjac glucomannan beads have been investigated as metal biosorbent for Pb(II) from aqueous solutions. The effect of contact time, solution pH, initial metal concentration, and desorption were studied in batch experiments at 20°C±2°C. Maximum mental sorption was found to occur at initial pH 4.0–5.5. Kinetic studies revealed that the initial uptake was rapid and equilibrium was established in 3 h and that the data followed the prseudo-second order reaction. The equilibrium sorption data at initial pH 4.0 were described by the Langmuir and Freundlich isotherm models; however, Langmuir isotherm model has been found to provide the best correlation. The highest value of Langmuir maximum uptake (q max) was found to be 105.71 mg·g?1. Similar Freundlich empirical constant (K F) was obtained to be 1.98 for lead. Adsorption-complexation may be involved in the sorption process of lead. Desorption experiments showed evidence that after two contacts neither HCl nor EDTA solutions were able to desorb lead from the konjac glucomannan beads, but the desorbtion efficacy of HCl solution was higher than EDTA solution. The results obtained show that konjac glucomannan beads may be used for the treatment of wastewater contaminated with lead.

关键词： lead konjac glucomannan beads wastewater biosorption

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Non-Oxidative Methane Conversion Using Lead- and Iron-Modified Albite Catalysts in Fixed-Bed Reactor

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Chinese Journal of Chemistry 2018年第6期36卷 531-537页

作者： Ye Chen Xin Wang xuegang luo Xiaoyan Lin Yu Zhang Department of Materials Science and Engineering Southwest University of Science and Technology Mianyang Sichuan 621010 China Engineering Research Center of Biomass Materials Ministry of Education Mianyang Sichuan 621010 China

Raw and modified albite catalysts, including Pb/Atbite and Fe/Albite catalysts, have been investigated for methane conversion to C2 hydrocarbons under non-oxidative conditions. Introduction of Pb to albite improved the activity and selectivity to non-coke products. Based on characterization, it was found that Pb entered into the alkali and alkaline-earth metal sites of albite, while partial Fedoped in the tetrahedron sites and the other loaded on the surface of albite. At the reaction temperature of 1073 K, methane gas hourly space velocity （GHSV） of 2 ***-1·h-1, catalyst dosage of 0.25 g （300 mesh）, the methane conversion catalyzed by raw albite in the fixed-bed micro reactor exhibited a methane conversion of 3.32%. Notably, introducing a Pb content of 3.4 wt% into albite greatly enhanced the conversion of methane up to 8.19%, and the selectivity of C2 hydrocarbons reached 99% without any coke under the same reaction conditions. While Fe-doping could weakly heighten the methane conversion to 3.97%, and coke was formed. Thus, a comparison of Pb/Albite and Fe/Albite catalysts demonstrates that the catalytic activity of albite is mainly decided by alkali and alkaline-earth metal sites, and lead-modification can effectively improve the catalytic activity of albite.

关键词： methane conversion albite C2 hydrocarbons active site lead-modification

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放线菌来源的天然产物及其挖掘技术

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生命的化学 2024年第7期44卷 1184-1191页

作者：刘竹青王俊潇徐飞罗学刚天津科技大学生物工程学院工业发酵微生物教育部重点实验室天津300457 齐鲁晟华制药有限公司德州251500 浙江大学医学院药物生物技术研究所杭州310000

以初级代谢产物为前体,合成一些对微生物生命活动并无明显功能但结构较为复杂的物质即次级代谢产物,也称天然产物。微生物天然产物具有丰富的骨架多样性和结构复杂性,且这些物质大多具有抗菌、杀虫、抗肿瘤等活性,是抗生素等先导化合物... 详细信息

以初级代谢产物为前体,合成一些对微生物生命活动并无明显功能但结构较为复杂的物质即次级代谢产物,也称天然产物。微生物天然产物具有丰富的骨架多样性和结构复杂性,且这些物质大多具有抗菌、杀虫、抗肿瘤等活性,是抗生素等先导化合物的重要来源,在新药研发过程中具有巨大优势,并广泛应用于人类医药、农业、化工等多个领域。本文综述了近几年来放线菌来源的天然产物及其挖掘策略的研究进展。

关键词：放线菌天然产物挖掘策略

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芦台春酱香型白酒酿造过程中真菌菌群多样性及代谢分析

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中国酿造 2024年第4期43卷 45-52页

作者：王佳丽胥强路程顺赵淑先张同存罗学刚天津科技大学生物工程学院天津300457 天津科技大学工业发酵微生物教育部重点实验室暨天津市工业微生物重点实验室天津300457 山西师范大学食品科学学院山西太原030031 天津芦台春酿造有限公司天津301500

该研究采用高通量测序技术对天津芦台春酱香型白酒发酵过程中不同轮次出窖酒醅的真菌群落结构进行研究,并对其与理化因子、挥发性风味成分相关性分别进行典范对应分析(CCA)及偏最小二乘判别分析(PLS-DA)。结果表明,随着轮次的增加,真菌... 详细信息

该研究采用高通量测序技术对天津芦台春酱香型白酒发酵过程中不同轮次出窖酒醅的真菌群落结构进行研究,并对其与理化因子、挥发性风味成分相关性分别进行典范对应分析(CCA)及偏最小二乘判别分析(PLS-DA)。结果表明,随着轮次的增加,真菌菌群的多样性升高,而丰度先升高后降低;酵母菌是白酒发酵过程中的主要真菌,但相对丰度逐步降低,在属水平上以伊萨酵母属(Issatchenkia)为主,其相对丰度由第一轮次的97.48%逐渐下降至第七轮次的3.53%。相关性分析结果表明,总酸、还原糖和酒精度是窖池发酵微生物演替的重要理化因子;伊萨酵母属(Issatchenkia)与乙酸乙酯、乙酸异戊酯、异戊醇等相关性较大;哈萨克斯坦酵母属(Kazachstania)、丝衣霉属(Byssochlamys)、罗萨氏菌属(Rasamsonia)、复膜孢酵母属(Saccharomycopsis)等与正己酸乙酯、庚酸乙酯、3-羟基丁酸乙酯、丁二酸二乙酯、苯乙酸乙酯、油酸乙酯、乙醇等相关性较大;而Leiothecium、未分类的酵母目(unclassified_o__Saccharomycetales)、Apiotrichum、Cutaneotrichosporon等则对壬酸乙酯、乙酸苯乙酯、正己醇、2,3-丁二醇、糠醇、糠醛等的形成起到重要作用。

关键词：酱香型白酒酒醅真菌菌群多样性理化因子挥发性风味物质相关性分析

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Production and Characterization of Spherical Porous Lignin Pellets

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稀有金属材料与工程 2011年第S3期40卷 188-192页

作者： Li Xianfa, luo xuegang Southwest University of Science and Technology, Mianyang 621010, China SW Univ Sci & Technol Mianyang 621010 Peoples R China

With industrial kraft lignin as precursors, the transformer oil as dispersive phase, addin sodium dodecyl sulfate as dispersant and epichlorohydrin as crosslinking agent, the spheric porous lignin pellets were produced by two-phase solvent system. The suitable process conditions of producing the lignin pellets were determined by signal-factor and orthogonal experiments. The lignin pellets were characterized by scanning electron microscopy (SEM), fourier transform infrared spectroscopy (FT-IR), thermogravimetry and X-ray diffraction analysis. The results show that the ideal spherical lignin pellets with 87.75% of the yield could be obtained under the such conditions as 5 g lignin dissolved in 50 ml water by adjusting the solution pH value to 13, 0.6 g sodium dodecyl sulfate, 3 g epichlorohydrin and 150 ml transformer oil. Morphology studies show that lignin pellets have the full spheric shape and inner porous microstructure. Evidence for the reaction between lignin and epichlorohydrin has been observed using FT-IR and thermogravimetric analysis. The results of X-ray diffraction analysis demonstrate that crosslinked lignin pellets mainly are an amorphous polymer.

关键词： Kraft lignin two-phase solvent system spherical porous lignin pellets

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Response mechanism of Chlamydomonas reinhardtii to nanoscale bismuth oxyiodide(nano-BiOI):Integrating analysis of mineral nutrient metabolism and metabolomics

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Journal of Environmental Sciences 2022年第11期34卷 13-24页

作者： Yan Huang Jinlong Lai Yang Huang xuegang luo Xu Yang Zewei Liu Yue Duan Chen Li School of Life Sciences Southwest University of Science and TechnologyMianyang 621010China College of Environment and Resources Southwest University of Science and TechnologyMianyang 621010China Laboratory of Solid Waste Treatment and Resource Recycle Ministry of EducationMianyang 621010China College of Chemical and Environment Science Shaanxi University of TechnologyHanzhong 723000China

Nanoscale bismuth oxyiodide(nano-BiOI) is widely studied and applied in environmental applications and biomedical fields, with the consequence that it may be deposited into aquatic environments. However, the impact of nano-Bi OI on aquatic ecosystems, especially freshwater microalga, remains limited. Herein, the nano-Bi OI was synthesized and its response mechanism towards microalga Chlamydomonas reinhardtii was evaluated. Results showed that a low concentration of nano-Bi OI(5 mg/L) could stimulate algal growth at the early stage of stress. With the increase in concentration, the growth rate of algal cells was inhibited and showed a dose effect. Intracellular reactive oxygen species(ROS) were significantly induced and accompanied by enhanced lipid peroxidation, decreased nonspecific esterase activity, and significantly upregulated glutathione S-transferase activity(GST) activity. Mineral nutrient metabolism analysis showed that nano-Bi OI significantly interfered with the mineral nutrients of the algae. Non-targeted metabolomics identified 35 different metabolites(DEMs, 22 upregulated, and 13 downregulated) under 100 mg/L Bi OI *** pathway analysis demonstrated that a high concentration of nano-Bi OI significantly induced metabolic pathways related to amino acid biosynthesis, lipid biosynthesis,and glutathione biosynthesis, and significantly inhibited the sterol biosynthesis *** finding will contribute to understanding the toxicological mechanisms of nano-Bi OI on C. reinhardtii.

关键词： Chlamydomonas reinhardtii Nano-BiOI Mineral nutrient Metabolomics

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二氧化硅纳米颗粒暴露对莱茵衣藻生长及细胞代谢的影响

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防化研究 2024年第4期3卷 67-76页

作者：陶美胡雨晴赖金龙罗学刚张宇西南科技大学环境与资源学院生物质材料教育部工程研究中心西南科技大学生命科学与工程学院

为评估二氧化硅纳米颗粒（Silica Nanoparticles, SiO2NPs）对淡水微藻的影响，本研究以莱茵衣藻为供试对象，分析了不同浓度SiO2NPs暴露对莱茵衣藻生长速率、活性氧（Reactive Oxygen Species, ROS）、叶绿素和微藻代谢网络的影响。研... 详细信息

为评估二氧化硅纳米颗粒（Silica Nanoparticles, SiO2NPs）对淡水微藻的影响，本研究以莱茵衣藻为供试对象，分析了不同浓度SiO2NPs暴露对莱茵衣藻生长速率、活性氧（Reactive Oxygen Species, ROS）、叶绿素和微藻代谢网络的影响。研究发现：当SiO2NPs为400～800 mg/L时，其可显著抑制莱茵衣藻的增殖；200～800 mg/L的SiO2NPs暴露后，莱茵衣藻叶绿素a和叶绿素b的浓度分别较对照组下降27.89%～42.16%和16.28%～26.3%，且藻细胞内产生的ROS较对照组上升9.25%～24.9%;100 mg/L和800 mg/L的SiO2NPs显著改变了莱茵衣藻的代谢网络，包括脂质和类脂质分子、有机杂环化合物、有机酸及其衍生物等。通过代谢物分类注释基础代谢网络后分析发现，SiO2NPs影响了莱茵衣藻甘油磷脂类和有机杂环化合物代谢，特别是吲哚、吡啶、咖啡因等，并导致莱茵衣藻碳水化合物代谢、核苷酸合成、脂类和氨基酸代谢等基础代谢过程异常。本研究可为探索SiO2NPs对微藻的生物效应提供一定的理论基础和数据支持。

关键词：二氧化硅纳米颗粒莱茵衣藻代谢组学生长曲线活性氧

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甘麦大枣露酒制备工艺优化

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中国酿造 2024年第5期43卷 150-155页

作者：胥强王佳丽王雪芳杨珍李寒露王怡宁霍超罗学刚天津科技大学生物工程学院工业发酵微生物教育部重点实验室暨天津市工业微生物重点实验室天津300457 生物工程国家级实验教学示范中心天津300457 天津芦台春酿造有限公司天津301500

为了迎合当前多样性的露酒市场,以甘草、红枣和小麦为原料制备甘麦大枣露酒,对露酒浸提工艺、配方以及澄清条件进行优化,并对产品进行感官评价和理化分析。结果表明,甘麦大枣露酒的最佳浸提工艺为乙醇体积分数60%、料液比24∶100(g∶mL... 详细信息

为了迎合当前多样性的露酒市场,以甘草、红枣和小麦为原料制备甘麦大枣露酒,对露酒浸提工艺、配方以及澄清条件进行优化,并对产品进行感官评价和理化分析。结果表明,甘麦大枣露酒的最佳浸提工艺为乙醇体积分数60%、料液比24∶100(g∶mL)、超声提取时间60 min、超声提取温度80℃、超声提取功率225 W、浸泡时间2 h。在此条件下,总黄酮含量最高达到了0.39 mg/mL;最佳甘麦大枣露酒配方为每100 mL的甘麦大枣露酒含8 mL甘麦大枣浸提浓缩液、63 mL 60%vol白酒基酒、29 mL纯净水和2 g的白砂糖,之后以0.4 g/L的皂土进行澄清,所制得的甘麦大枣露酒酒体澄清透明,口味鲜明,口感醇厚。

关键词：露酒甘麦大枣汤制备工艺澄清

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Preparation of rabbit anti-rat LRRN3 polyclonal antibody and study of its expression

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Neural Regeneration Research 2010年第13期5卷 1030-1034页

作者： Jing Yang Yanjin Wang Yan Cai Zhiying Yang Ganqiu Wu Jianguo Wen xuegang luo He Huang Department of Histology and Embryology Xiangya School of Medicine Central South University Changsha 410013 Hunan Province China Department of Human Anatomy and Neurobiology Xiangya School of Medicine Central South University Changsha 410013 Hunan Province China Department of Neurosurgery Xiangya Hospital Central South University Changsha 410013 Hunan Province China

BACKGROUND： Studies have shown that the Repeat superfamily, could be related to neural LRRN3, a member of the Neuron Leucine-Rich development, differentiation, information transmission, and other functions, but most studies have focused on nucleic acid levels and few have reported on LRRN3 protein levels. OBJECTIVE： To prepare rabbit anti-rat LRRN3 polyclonal antibody and to observe protein tissue expression profiles. DESIGN, TIME AND SEI-rlNG： In vitro, molecular, biological experiments were performed from October 2007 to April 2009 in Laboratory of Neurobiology at Xiangya School of Medicine, Central South University. MATERIALS： Immunization antigen, namely rat MaI-LRRN3C-His recombinant protein, was provided by the Laboratory of Neurobiology at Xiangya School of Medicine, Central South University. METHODS： Rat Mal-LRRN3C-His recombinant protein was used to immunize male, New Zealand rabbits, and rabbit anti-rat LRRN3 polyclonal antibody was prepared. MAIN OUTCOME MEASURES： Antibody purification was conducted using Protein A affinity chromatography, and the LRRN3 anti-serum titer was identified using enzyme-linked immunosorbent assay. Immunohistochemical techniques and Western blot preliminary tests were used to determine LRRN3 protein expression profiles in adult rats. RESULTS： A highly purified rabbit anti-rat LRRN3 polyclonal antibody was obtained. Western Blot results from rat brain total protein revealed a band at 79 kD, which was consistent with the size of LRRN3. Immunohistochemistry results showed that protein was mainly expressed in the central nervous system, and no significant positive signals were observed in other tissues. Positive cells included neurons of cerebral cortex and hippocampal dentate gyrus granule cell layer, and cerebellar Purkinje cells. There was no positive expression in glial cells. CONCLUSION： Rabbit anti-rat LRRN3 polyclonal antibody was successfully prepared at a high purity from the prokaryotic-expressed MaI-LRRN3C-His recombinant

关键词： polyclonal antibody preparation protein expression LRRN3 developmental neurobiology neural regeneration

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