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2023 1

2021 2

2017 2

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假单胞菌 1

富含异亮氨酸的延伸蛋白 1

环状脂肽 1

类受体激酶 1

细胞死亡 1

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LYX: A novel aerobic bacterium with advantage of removing nitrate high effectively by assimilation and dissimilation simultaneously

Yuxin Li, Jiayin Ling, Pengcheng Chen, Jinliang Chen, Ruizhi Dai, Jinsong Liao, Jiejing Yu, Yanbin Xu

《环境科学与工程前沿（英文）》 2021年第15卷第4期 doi: 10.1007/s11783-020-1349-3

摘要： Abstract • Pseudomonas mendocina was first reported for aerobic nitrate removal. • It removed 90% of NO3−-N in 24 h under aerobic conditions. • This strain converted NO3−-N to bio-nitrogen (37.9%) and gaseous nitrogen (49.7%). • Inoculation of this strain increased sludge denitrification rate by 4.3 times. The problem of nitrate accumulation in aerobic tank and total nitrogen excessive discharge in effluent was very common in traditional livestock and poultry farming wastewater treatment systems owing to the lengthy process flow and low process control level. A strain LYX of aerobic bacterium was isolated from the activated sludge of a wastewater treatment system in a pig farm, which could remove nitrate effectively in aerobic tank and was identified Pseudomonas mendocina by 16S rRNA sequencing. Under the condition of nitrate as the sole nitrogen source, this strain removed over 90% of NO3−-N with an initial concentration of 110 mg/L under aerobic conditions within 48 hours. Among them, 37.9% of NO3−-N was assimilated into Bio-N, about 51.9% was reduced to gaseous nitrogen and less than 0.5% of nitrogen was replaced by NO2−-N and NH4+-N, 9.7% NO3−-N remained in the effluent at the end. At the same time, four key genes (napA, nirK, norB and nosZ) related to nitrate nitrogen removal were expressed during the denitrification process of P. mendocina LYX, in which the transcription level of the indicator genes of this aerobic denitrifying bacterium (napA) was the highest. In addition, it was found with the 15N tracer technique that inoculation of this strain on sludge increased the amount of nitrogen loss from 9.26 nmol N/(g·h) to 23.835 nmol N/(g·h). Therefore, P. medocina LYX is a potential bioagent for advanced nitrogen removal by assimilating and reducing nitrate simultaneously in aerobic tanks.

关键词： Pseudomonas mendocina Aerobic nitrate removal ¹⁵N tracing technique Denitrification assimilatively and disimilatively Aerobic denitrifying genes

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Selective pseudosolubilization capability of

Fei HUA, Hongqi WANG

《环境科学与工程前沿（英文）》 2013年第7卷第4期页码 539-551 doi: 10.1007/s11783-013-0498-z

摘要： Pseudosolubilized ability of sp. DG17 on -alkanes, role of biosurfactants in -octadecane uptake and trans-membrane transport mechanism of -octadecane were studied by analyzing amount of pseudosolubilized oil components in water phase, and the fraction of radiolabeled C -octadecane in the broth and cell pellet. GC-MS results showed that pseudosolubilized oil components were mainly C to C of -alkanes. In -octadecane broth, pseudosolubilized -octadecane could be accumulated as long as pseudosolubilized rate was faster than mineralization rate of substrate, and the maximum concentration of pseudosolubilized -octadecane achieved to 45.37 mg·L . All of these results showed that sp. DG17 mainly utilized alkanes by directly contacting with pseudosolubilized small oil droplets in the water phase. Analysis of C amount in cell pellet revealed that an energy-dependent system mainly controlled the trans-membrane transport of -octadecane.

关键词： Pseudomonas alkane uptake pseudosolubilization trans-membrane transport

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Rhamnolipid synthesis and production with diverse resources

Qingxin Li

《化学科学与工程前沿（英文）》 2017年第11卷第1期页码 27-36 doi: 10.1007/s11705-016-1607-x

摘要： Rhamnolipids are one of the most effective biosurfactants that are of great interest in industrial applications such as enhancing oil recovery, health care, cosmetics, pharmaceutical processes, food processing, detergents for protein folding, and bioremediation due to their unique characteristics such as low toxicity, surface active property to reduce surface/interfacial tensions, and excellent biodegradability. The genes and metabolic pathways for rhamnolipid synthesis have been well elucidated, but its cost-effective production is still challenging. , the most powerful rhamnolipid producer, is an opportunistic pathogen, which limits its large scale production and applications. Rhamnolipid production using engineered strains other than such as and has received much attention. The highest yield of rhamnolipids is achieved when oil-type carbon sources are used, but using cheaper and renewable carbon sources such as lignocellulose would be an attractive strategy to reduce the production cost of rhamnolipids for various industrial applications.

关键词： biosurfactant rhamnolipid Pseudomonas waste surface tension

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Production of rhamnolipids-producing enzymes of

Kata Kiss,Wei Ting Ng,Qingxin Li

《化学科学与工程前沿（英文）》 2017年第11卷第1期页码 133-138 doi: 10.1007/s11705-017-1637-z

摘要： Rhamnolipids are a class of biosurfactants that have a great potential to be used in industries. Five proteins/enzymes, namely RhlA, RhlB, RhlC, RhlG and RhlI, are critical for the production of rhamnolipids in . Four of the 5 proteins except RhlC were successfully over-expressed in and three of them (RhlA, RhlB and RhlI) were purified and obtained in milligram quantities. The purified proteins were shown to be folded in solution. Homology models were built for RhlA, RhlB and RhlI. These results lay a basis for further structural and functional characterization of these proteins to favor the construction of super strains for rhamnolipids production.

关键词： rhamnolipids Pseudomonas RhlA RhlB RhlI protein folding

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Toxic effect of sodium perfluorononyloxy-benzenesulfonate on in aerobic denitrification, cell structure and gene expression

《环境科学与工程前沿（英文）》 2021年第15卷第5期 doi: 10.1007/s11783-021-1391-9

摘要：

• OBS inhibited the growth of P. stutzeri and destroyed its structure.

关键词： Sodium perfluorononyloxy-benzenesulfonate Aerobic denitrification Pseudomonas stutzeri Ecotoxicity ROS Persist organic pollutants Toxicity Denitrification Microbiology

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假单胞菌环状脂肽Medpeptin的生物合成及其调控植物免疫的作用机制 Article

谷医林, 李俊州, 李彦, 从珅, 王静, 马毅楠, 魏海雷

《工程（英文）》 2023年第28卷第9期页码 153-165 doi: 10.1016/j.eng.2023.05.016

摘要：

环状脂肽（cyclic lipopeptides, CLP）是一类由细菌产生的多功能次生代谢产物，也是一类重要的植物免疫激发子。假单胞菌环状脂肽在结构和生物活性上极其复杂和多样化。但是，目前对环状脂肽的结构及其与植物互作中的功能认识仍比较有限。本研究从地中海假单胞菌中鉴定了一种由22个氨基酸组成的新型的环状脂肽medpeptin，该脂肽由一个非核糖体肽合成酶基因簇合成并受群体感应系统调节。进一步研究发现，medpeptin可以诱导植物产生免疫反应，增强植物对病原细菌的抗性，但其自身不具备抗菌活性。利用比较转录组分析和病毒诱导的基因沉默技术解析了参与medpeptin感知植物免疫信号候选关键基因。结果显示，当沉默本氏烟中细胞壁富含亮氨酸的重复延伸蛋白NbLRX3或类受体蛋白激酶NbRLK25后，medpepatin触发的细胞死亡和对病原细菌的抗性受到严重影响，而沉默BAK1或SGT1则并未影响这一表型。本研究结果揭示了一种非典型的CLP感知机制，并为植物抗病免疫研究提供了新的借鉴。

关键词：假单胞菌环状脂肽细胞死亡富含异亮氨酸的延伸蛋白类受体激酶