Supplemental N-acyl homoserine lactonase alleviates intestinal disruption and improves gut microbiota in broilers challenged by Salmonella Typhimurium

Background Salmonella Typhimurium challenge causes a huge detriment to chicken production.N-acyl homoserine lactonase(AHLase),a quorum quenching enzyme,potentially inhibits the growth and virulence of Gram-negative bacteria.However,it is unknown whether AHLase can protect chickens against S.Typhimurium challenge.This study aimed to evaluate the effects of AHLase on growth performance and intestinal health in broilers challenged by S.Typhimurium.A total of 240 one-day-old female crossbred broilers(817C)were randomly divided into 5 groups(6 replicates/group):negative control(NC),positive control(PC),and PC group supplemented with 5,10 or 20 U/g AHLase.All birds except those in NC were challenged with S.Typhimurium from 7 to 9 days of age.All parameters related to growth and intestinal health were determined on d 10 and 14.Results The reductions(P<0.05)in body weight(BW)and average daily gain(ADG)in challenged birds were alleviated by AHLase addition especially at 10 U/g.Thus,samples from NC,PC and PC plus 10 U/g AHLase group were selected for further analysis.S.Typhimurium challenge impaired(P<0.05)intestinal morphology,elevated(P<0.05)ileal inflammatory cytokines(IL-1βand IL-8)expression,and increased(P<0.05)serum diamine oxidase(DAO)activity on d 10.However,AHLase addition normalized these changes.Gut microbiota analysis on d 10 showed that AHLase reversed the reductions(P<0.05)in several beneficial bacteria(e.g.Bacilli,Bacillales and Lactobacillales),along with increases(P<0.05)in certain harmful bacteria(e.g.Proteobacteria,Gammaproteobacteria,Enterobacteriaceae and Escherichia/Shigel a)in PC group.Furthermore,AHLase-induced increased beneficial bacteria and decreased harmful bacteria were basically negatively correlated(P<0.05)with the reductions of ileal IL-1βand IL-8 expression and serum DAO activity,but positively correlated(P<0.05)with the increased BW and ADG.Functional prediction revealed that AHLase abolished S.Typhimurium-induced upregulations(P<0.05)of certain pathogenicity-related pathways such as lipopolysaccharide biosynthesis,shigellosis,bacterial invasion of epithelial cells and pathogenic Escherichia coli infection of gut microbiota.Conclusions Supplemental AHLase attenuated S.Typhimurium-induced growth retardation and intestinal disruption in broilers,which could be associated with the observed recovery of gut microbiota dysbiosis.

Degradation of N-Acyl Homoserine Lactone Quorum Sensing Signals by Bacillus thuringiensis AHL Lactonase

Bacterial cells rely on signaling molecules to communicate with others from the same species and induce certain genes in a process known as quorum sensing (QS). A common molecule is N-acyl homoserine lactone (AHL) which is responsible for the expression of virulence and other factors that allow the organisms to compete in a given environment. On the other hand, other bacteria produce certain enzymes such as AHL-lactonase that break down AHL molecules and prevent gene expression of these factors. The aim of this work was to examine the level of degradation of AHL molecules by AHL-lactonase in 62 Bacillus thuringiensis (Bt) strains isolated from Middle Tennessee, Mississippi, and Alabama. N-hexanoyl-homoserine lactone (C6-HSL) and N-3-oxo-hexanoyl homoserine lactone (3-oxo-C6-HSL), which cause Chromobacterium violaceum (CV026) to produce a purple pigment were tested at different concentrations to view the Bt lactonase activity. In addition, PCR was used to test for the presence of the lactonase gene. The results showed that among the 62 Bt strains, there were 58 that possessed the AHL-lactonase (aiiA) gene and 48 strains were able to degrade C6-HSL. At high concentrations of AHL, only 13 strains were able to completely degrade C6-HSL. In addition, degradation of 3-oxo-C6-HSL was weak compared to C6-HSL. The results also revealed that AHL lactonase was thermostable, and it was concluded that the level of degradation varies in Bt strains. Only 13 of the strains studied have potent inhibitory activity against C6-HSL, which may be good to be used in field applications to control agricultural pest.

A Preliminary Study of Cell Membrane Mediated Immobilization of a Recombinant Acyl-homoserine Lactonase AidH

The aim of this work was to inhibit biofilm formation by taking advantages of bacterial surface display technology in combination with cell membrane chromatography.A recombinant protein INPAidH was constructed by fusing a quorum signal hydrolase AidH to the C-terminus of the ice nucleation protein(INP).Expression of INP-AidH was achieved on E.coli cell surface at an expression level of 30%of total membrane proteins.Activity of INP-AidH on cell membranes was confirmed in degrading the quorum signal C6-HSL as well as inhibiting bacterial biofilm.Immobilization of INP-AidH anchored cell membranes on silica gel particles was facilitated by taking advantages of cell membrane chromatography.The functionalized silica gel particles also exhibit activities in degrading C6-HSL and inhibiting bacterial biofilm.This article presents a new approach to prevent biofilm formation of silica-based materials.

N-Acylhomoserine Lactones (AHLs), QseB/C Gene Detection, Virulence Factors and Antibiotics Resistance of <i>Aeromonas hydrophila</i>

The aim of this research was to detect the N-acyl homoserine lactones (AHLs) production and QseB/C gene of Aeromonas hydrophila. We analyzed the potentials of these isolates of Aeromonas hydrophila in causing biofilm formation, hemolysis, protease, and lipase. The antibiotic susceptibility of the 15 Aeromonas hydrophila isolates was also investigated. The detection of AHLs was carried out using the Chromobacterium violaceum strain CV026 as biosensors. The isolated strains were tested for the reaction of C. violaceum CV026 by cross-streaking on an agar plate. Production of AHLs was determined by the diffusing via the agar plates and the tinge of the biosensor strains. All isolated strains produced AHLs. A polymerase chain reaction (PCR) showed the isolated strains had qseB and qseC genes. Susceptibility tests of A. hydrophila isolates were administered against 25 different antibiotic disks representing 12 classes of antibiotics. The strains were highly resistant to β-Lactam with 96.7% showing resistibility, whereas 97.7% susceptibility was found towards Aminoglycoside class of the antibiotic used. 60% showed intermediate resistant to Polypeptide. 100% of the strains showed no resistant to Aminoglycoside, Polypeptide, Monobactam, and Carbapenems class of antibiotics. Each of the isolates was found to be associated with at least one virulent factor. Our results clearly demonstrated that there is a presence of QseB/C genes in A. hydrophila and also produces AHLs molecule and virulence factors. The investigated isolates showed the pathogenic potential of Aeromonas hydrophila which makes it a serious threat to public health.

Occurrence of <i>N</i>-Acyl Homoserine Lactones in Extracts of Bacterial Strain of <i>Pseudomonas aeruginosa</i>and in Sputum Sample Evaluated by Gas Chromatography–Mass Spectrometry

This study presents a fast, accurate and sensitive technique using gas chromatography-mass spectrometry (GC-MS) for the identification and quantification of N-acyl homoserine lactones (AHLs) in the extracts of bacterial strain of Pseudomonas aeruginosa and sputum sample of a cystic fibrosis patient. This method involves direct separation and determination of AHLs by using GC-MS as simultaneous separation and characterization of AHLs were possible without any prior derivatiza-tion. Electron ionization resulted in a common fragmentation pattern with the most common fragment ion at m/z 143 and other minor peaks at 73, 57 and 43. The limit of detection for N-butanoyl, N-hexanoyl, N-octanoyl, N-decanoyl, N-dodecanoyl and N-tetradecanoyl homoserine lactones was 2.14, 3.59, 2.71, 2.10, 2.45 and 2.34 μg/L, respectively. The presence of AHLs in the culture of P. aeruginosa strain and spu-tum of a cystic fibrosis patient was achieved in selected ion monitoring (SIM) mode by using the prominent fragment at m/z 143.

Characterization of acylated homoserine lactone derivatives and their influence on biofilms of Acidithiobacillus ferrooxidans BY-3 under arsenic stress

Quorum sensing is one kind of cell-to-cell signalling system among microorganisms that works in response to their population density via autoinducers exemplified by AHL and oligopeptides. In this study, fourteen AHL derivatives were synthesised by a chemical synthesis method, and two types of AHL derivatives were measured and screened by crystal violet staining assay, which have more obvious inhibitory effects on A. ferrooxidans biofilms under arsenic environment. Their structures were verified through IR and NMR identification. The morphological changes of A. ferrooxidans under the influence of the AHL derivatives were compared. In addition, the effects of AHL derivatives(0.1 μg/mL and 1 μg/mL) on membrane formation of A. ferrooxidans under high concentration of arsenic resistance(1,600 mg/L) were explored. Solid experimental data firstly showed that a portion of logarithmic microorganisms were ruptured under the effect of high arsenic concentration. Secondly, the volume of the cell shrank and the number of extracellular polymeric substances decreased after the addition of the AHL derivatives at high concentrations. Therefore, we found here that two derivatives used at concentrations of 0.1 μg/mL and 1 μg/m L accompanied with high concentration of arsenic can both effectively restrict biofilms formation by A. ferrooxidans.

Monooxygenase Gene from Acinetobacter sp. C42 Inactivates the Acyl Homoserine Lactone Quorum Sensing Signal

[ Objective] This study aimed to investigate the function of aliD gene in the inactivation of AHLs. [ Method ] A bacterial isolate, Acinetobacter sp. CA2 from soil, is capable of inactivation of AHLs. A gene designed as aliD, which is responsible for AHL-quenching activity and exhibits high similarity with Mo- nooxygenase genes, was cloned from the genomic library of Acinetobacter sp. CA2. [ Result ] The aliD gene in-frame deletion mutant, CA2 AliD, impaired its AHLs inactivating function when mixed with N-（3-oxooctanoyl） -L-homosefine lactone （30C8-HSL）. Expression of AliD in plant pathogenic bacterium Pectobacterium ca- rotovorum subsp, carotovorum Z3-3 significantly reduced the AHLs production and the extracellular pectolytic enzyme activities, and attenuated soft rot disease symptoms on the plants tested, including potato, Chinese cabbage, radish and cabbage. [ Conclusion ] Our study suggests that the aliD gene complemented strain CA2-AliD showes a similar AHLs inactivating function.

N-acyl homoserine lactonase attenuates the virulence of Salmonella typhimurium and its induction of intestinal damages in broilers

This study aimed to investigate the potential mitigating effects of N-acyl homoserine lactonase(AHLase)on the virulence of Salmonella typhimurium and its induction of intestinal damages in broilers.In vitro study was firstly conducted to examine if AHLase treatment could attenuate the virulence of S.typhimurium.Then,an in vivo experiment was performed by allocating 240 broiler chicks at 1 d old into 3 groups(8 replicates per group):negative control(NC),positive control(PC),and PC supplemented with 10,000 U/kg AHLase.All chicks except those in NC were orally challenged by S.typhimurium from 8to 10 d of age.Parameters were measured on d 11 and 21.The results showed that treatment with 1 U/mL AHLase suppressed the biofilm-forming ability(including biofilm biomass,extracellular DNA secretion and biofilm formation-related gene expression),together with swarming motility and adhesive capacity of S.typhimurium.Supplemental 10,000 U/kg AHLase counteracted S.typhimurium-induced impairments(P<0.05)in broiler growth performance(including final body weight,average daily gain and average daily feed intake)during either 1-11 d or 12-21 d,and increases(P<0.05)in the indexes of liver,spleen and bursa of Fabricius on d 11,together with reductions(P<0.05)in ileal villus height and its ratio to crypt depth on both d 11 and 21.AHLase addition also normalized the increased(P<0.05)m RNA expression of ileal occludin on both d 11 and 21 in S.typhimurium-challenged broilers.However,neither S.typhimurium challenge nor AHLase addition altered(P>0.05)serum diamine oxidase activity of broilers.Noticeably,S.typhimurium challenge caused little change in the mRNA expression of ileal inflammatory cytokines except for an increase(P<0.05)in interleukin-8 expression on d 11,whereas AHLase addition normalized(P<0.05)this change.In conclusion,AHLase treatment could attenuate the virulence and pathogenicity of S.typhimurium,thus contributing to alleviate S.typhimurium-induced growth retardation and intestinal damages in broilers.

群体感应分子3OC12HSL对小鼠生长、血液和肠道的影响

本研究旨在探讨群体感应分子3OC12HSL对小鼠生长、炎症因子及肠粘膜屏障的影响。采用高剂量盐酸林可霉素灌胃方法建立小鼠腹泻模型,对正常小鼠和腹泻模型小鼠分别灌胃生理盐水、二甲基亚砜(DMSO)、溶于DMSO的3OC12HSL溶液。结果显示,灌胃3OC12HSL降低正常小鼠和腹泻小鼠的增重,提高血清中D-乳酸、TNF-α含量,降低大肠长度及空肠和回肠绒毛长度(P<0.05);腹泻提高血清中IL-1、IL-8、TNF-α含量,降低空肠及回肠绒毛长度(P<0.05);灌胃3OC12HSL和腹泻对回肠绒隐比有协同降低趋势,但差异不显著(P>0.05)。综上,3OC12HSL不利于小鼠的生长,腹泻可能加重3OC12HSL的影响。

AHLs介导的群体感应和群体淬灭对植物-根际微生物相互作用的影响

根际是由植物根系和土壤微生物之间相互作用形成的一种特殊环境,根际微生物群落的宏基因组是植物微生物组的重要组成部分。植物与根际微生物之间的相互作用是一个复杂的过程。在根际环境中,微生物群落利用复杂的种内和种间信号传导机制招募特定的微生物,协调并控制混合群落的行为,从而影响植物的生长发育和健康。根际微生物能够自发产生、释放特定的信号分子,并能感知其浓度变化,从而调节微生物的群体行为,这一调控系统称为群体感应(quorum sensing,QS)。QS系统的特征是合成和释放特定的信号分子。根际土壤细菌中存在多种QS信号分子,如N-酰基高丝氨酸内酯(AHLs)、二酮哌嗪、扩散信号因子、次生代谢物、植物激素类分子等。AHLs作为细菌中被广泛研究的QS信号分子,在植物与根际微生物的相互作用中发挥重要作用。本文综述了AHLs介导的群体感应机制,并讨论了AHLs在植物与根际微生物相互作用中的调节作用,包括AHLs对植物的生长发育、逆境耐受性和抗病性等方面的有益影响,以及AHLs介导的QS系统调控导致的根际致病菌对植物的有害影响,同时还探讨了基于AHLs的群体淬灭对植物-根际微生物相互作用的影响,以期为植物健康与农业生产提供新的思路和方法,推动可持续农业的发展。

高氮负荷下硫自养反硝化菌群的胞外聚合物和信号分子特征

硫自养反硝化工艺(SADN)受水力停留时间(HRT)和进水NO_(3)^(-)-N浓度的影响.通过逐步缩短HRT,提高进水NO_(3)^(-)-N浓度的方式探究工艺脱氮极限,同时解析在此过程中胞外聚合物(EPS)和信号分子酰基高丝氨酸内酯(AHLs)的变化特征以及微生物群落结构演替过程.在HRT从4.1h缩短至1.0h的过程中,硫自养反硝化菌群可快速适应环境,当HRT=1.0h,进水NO_(3)^(-)-N含量为40mg/L,系统的TN去除率为99.74%,脱氮负荷高达958.53mg/(L·d).在此过程中,EPS含量的增加以TB-PN和TB-PS为主,AHLs含量的增加以C4-HSL为主.较缩短HRT而言,提高进水NO_(3)^(-)-N浓度会促使C4-HSL含量显著增加并导致污泥结构逐渐趋向不稳定状态.C6-HSL是系统内最主要的AHLs,其含量在G4和G7阶段大幅增长是基于系统脱氮能力弱化后微生物所进行的自我调节.微生物群落组成分析表明,系统运行和氮负荷变化会对微生物群落进行驯化选择.在降HRT组中,Proteobacteria的norank_f_Pleomorphomona-daceae作为优势菌属发挥主要作用,为反硝化菌提供底物以维持系统稳定运行.在提高NO_(3)^(-)-N浓度后,UKL 13-1、Simplicispira、Allorhizobium-Neorhizobium-Pararhizobium-Rhizobium、Thermomonas逐渐演变为优势菌属,这些优势菌属均为具备脱氮功能的关键微生物.

Performance and role of N-acyl-homoserine lactone(AHL)-based quorum sensing(QS) in aerobic granules

The present study investigated the relationship between N-acyl-homoserine lactone（AHL）-based quorum sensing（QS） and the physico-chemical properties of aerobic granules.Stable mature granules were observed in SBR2 and SBR3 with average diameters of 0.96,and1.49 mm,respectively. The sludge densities of aerobic granules in SBR2 and SBR3 were1.0246,and 1.0201 g/mL,respectively,which were higher than that of flocculent sludge in SBR1（1.0065 g/mL）. The results showed that the activity of AHL-based QS in SBR2 and SBR3 amounted to 2.4- and 2.1-fold induction,however,that in SBR1 with flocculent sludge was1.6-fold induction. In addition,the results also showed that the activity of AHL-based QS in the three reactors rose in the feast condition,and then dropped with the consumption of substrate. However,the activity of AHL-based QS in these three reactors recovered again in prolonged starvation. Furthermore,the results showed that the enhancement of AHL-based QS favored the extracellular polymeric substance production of microorganisms in activated sludge. Thus,it could be concluded that aerobic granules showed higher AHL-based QS than flocculent sludge,which resulted from the higher sludge density of aerobic granules than flocculent sludge. AHL-based QS was related to the metabolism energy in the feast condition; however,in prolonged starvation,microorganisms would emit more AHL-like molecules to protect themselves to resist starvation. Moreover,the enhancement of AHL-based QS favored the EPS component productivity of the microorganisms in activated sludge,which contributed to maintain the aerobic granular structure.

Effects of exogenous short-chain N-acyl homoserine lactone on denitrifying process of Paracoccus denitrificans

N-acyl-homoserine lactones（AHLs） serve as quorum-sensing signals, which control a number of bacterial processes in many proteobacteria. Here we report the effects of exogenous short-chain AHL on the denitrifying process of Paracoccus denitrificans, which are capable of aerobic and anaerobic growth by utilizing nitrate. The denitrification activity of these cells was monitored by measuring denitrification products（including nitrate, nitrite,and nitrous oxide）, and the individual messenger ribonucleic acid（m RNA） levels of nitrate,nitrite, nitric oxide and nitrous oxide reductases. The results indicated that 2 μmol/L C6-homoserine lactone（HSL） has little effect on cell density under either anaerobic or aerobic culture conditions, and the nitrate reduction activity appeared slightly affected by N-hexanoyl-DL-homoserine lactone（C6-HSL）. However, exogenous C6-HSL significantly affected the transcription of nitrite reductase and nitric oxide reductase genes in P.denitrificans regardless of the presence of oxygen, and N2O accumulation activity in P. denitrificans was suppressed by C6-HSL under aerobic condition. In contrast, exogenous C6-HSL stimulated the production of N2O under anaerobic condition, suggesting that the regulation of denitrification by quorum sensing may be important in N2O release.

不同载体材料固定Sphingobium sp.PHE3对溶液中菲的降解研究

为探究不同载体材料对微生物降解菲的影响,以蒙脱石、针铁矿、玉米秸秆炭为载体,采用吸附挂膜法对菲降解菌株(革兰氏阴性菌鞘脂菌PHE3)进行固定化,并应用固定化微生物降解溶液中的菲。根据扫描电镜结果,该菌株在玉米秸秆炭载体表面附着生长数量最多,形态最优。添加蒙脱石和玉米秸秆炭显著(P<0.05)提高了微生物对菲的降解率,加快了菲的微生物降解速率,同时促进了细菌胞外聚合物(EPS)中多糖和蛋白质产量的增加,但添加针铁矿对菲的微生物降解和EPS的产生促进作用较弱。此外,鞘脂菌PHE3在形成生物膜的过程中可能有群体感应现象发生,能够分泌信号分子C_(8)-HSL和C_(12)-HSL,可能在一定程度上调控EPS的生成和污染物的降解。

Profile of the culturable microbiome capable of producing acyl-homoserine lactone in the tobacco phyllosphere

Bacterial populations coexisting in the phyllosphere niche have important effects on plant health. Quorum sensing （QS） allows bacteria to communicate via diffusible signal molecules, but QS-dependent behaviors in phyllosphere bacterial populations are poorly understood. We investigate the dense and diverse N-acyl-homoserine lactone （AHL）-producing phyllosphere bacteria living on tobacco leaf surfaces via a culture-dependent method and 16S rRNA gene sequencing. Our results indicated that approximately 7.9%-11.7% of the culturable leaf-associated bacteria have the ability to produce AHL based on the assays using whole-cell biosensors. Sequencing of the 16S rRNA gene assigned the AHL-producing strains to two phylogenetic groups, with Gammaproteobacteria （93%） as the predominant group, followed by Alphaproteobacteria. All of the AHL-producing Alphaproteobacteria were affiliated with the genus Rhizobium, whereas the AHL-producing bacteria belonging to the Gammaproteobacteria mainly fell within the genera Pseudomonas, Acinetobacter, Citrobacter, Enterobacter, Pantoea and Serratia. The bioassays of supernatant extracts revealed that a portion of the strains have a remarkable AHL profile for AHL induction activity using the two different biosensors, and one compound in the active extract of a representative isolate, NTL223, corresponded to 3-oxo-hexanoyl-homoserine lactone. A large population size and diversity of bacteria capable of AHL-driven QS were found to cohabit on leaves, implying that cross-communication based AHL-type QS may be common in the phyllosphere. Furthermore, this study provides a general snapshot of a potential valuable application of AHL-producing bacteria inhabiting leaves for their presumable ecological roles in the phyllosphere.

鱼源假单胞菌群体感应信号分子与腐败特性相关关系的研究

【目的】革兰氏阴性菌通过产生N-酰基-高丝氨酸内酯(AHLs)类信号分子,以密度依赖的方式调控某些生理特性的表达,即群体感应(QS)现象。假单胞菌是一种导致蛋白类食品腐败的重要腐败细菌。本研究的目的是确定假单胞菌群体感应信号分子与腐败特性的关系。【方法】利用AHLs检测菌对3株假单胞菌AHLs产生情况进行检测,并通过AHLS降解菌株对所产生的AHLs进行降解。【结果】3株菌均产生AHLs信号分子;菌株FML05-1、FML05-2至少产生两种AHLs分子,二者所产生的主要信号分子是N-3-氧代-辛酰基-高丝氨酸内酯(N-3-oxo-C8-HSL);FML05-2与降解AHLs的菌株共同培养,发现嗜铁素的产量与蛋白酶活性明显下降。【结论】FML05-2嗜铁素的产生和蛋白酶活性与AHLs有关。为以干扰腐败细菌群体感应为靶点的食品防腐保鲜策略提供研究基础。

带cry3 Aa启动子的aiiA基因在苏云金芽胞杆菌中的表达

N 乙酰高丝氨酸内酯 (N acyl homoserinelactones,AHLs) ,是一类数量感知 (Quorum sensing)系统中的信号分子 ,它参与诱导调控许多植物病原菌致病基因的表达。苏云金芽胞杆菌的AiiA蛋白能降解这类AHLs分子 ,进而可减弱病原菌致病基因表达产生的病害。苏云金芽胞杆菌杀虫晶体蛋白基因cry3Aa的启动子是一种不依赖芽胞形成的启动子 ,它相对于其它cry类基因的启动子有启动基因转录时间早 ,转录时间长的优点。通过重叠延伸PCR ,用杀虫晶体蛋白基因cry3Aa启动子替换编码AiiA蛋白的基因aiiA自身的启动子 ,构建了融合基因pro3A aiiA。将融合基因装入穿梭载体pHT3 0 4的BamHI SphI位点 ,得到重组质粒pBMB686并转化苏云金芽胞杆菌无晶体突变株BMB171,重组菌株BMB686的AiiA蛋白表达量在各个生长时期均高于对照菌株 。

生物膜中群体感应因子细菌的分离及成膜能力

从硝基苯甲酸废水处理系统的生物膜中分离到2株分泌酰基高丝氨酸内酯(AHL)群体感应信号分子的菌株M10和M22,测试表明M10产生4种AHL信号分子,M22产生3种AHL信号分子.以E.coliDH5α为对照,测定了这2株菌的成膜能力及群游力,M10和M22均表现出一定的成膜力和群游力,对比而言,M22的成膜能力较强,而M10的群游能力较强,M10和M22经个体形态、生理生化反应及16SrDNA测序初步鉴定均属Aeromonassp..

HPLC-MS法检测N-酰基-高丝氨酸内酯类信号分子

建立了HPLC-MS检测群体感应信号分子N-酰基-高丝氨酸内酯类(N-acyl-homoserine lactones,AHLs)化合物的方法。利用该方法对细菌发酵液中的AHLs进行分析,结果表明,样品只需简单的处理,在没有标样的条件下,可以对样品中任意的AHLs分子进行定性分析。该方法简单、高效,检测的灵敏度明显大于经典的TLC-B iosensor检测AHLs的方法,为从复杂混合物中鉴定AHLs提供了有效手段。

一株降解N-酰基高丝氨酸内酯酵母菌菌株的分离鉴定及其降解特性

利用N酰基高丝氨酸内酯(N-acyl-homoserine lactone,简称AHL)为唯一碳源和能源,筛选得到一株能够降解AHL的菌株R1。常规鉴定和18S rDNA序列分析表明,菌株R1属于红冬孢酵母菌(Rhodosporidium toruloides),定名为R.toruloidesR1。结果显示R.toruloidesR1能利用所测试的3种AHL作为唯一碳源和能源生长,具有降解AHL的能力,其对AHL依赖型胡萝卜欧文氏软腐病菌(Erwinia carotovora subsp.carotovora)的致病有一定的抑制作用。