Lazazzara Valentina, Perazzolli Michele, Pertot Ilaria, Biasioli Franco, Puopolo Gerardo, Cappellin Luca
Department of Sustainable Ecosystems and Bioresources, Research and Innovation Centre, Fondazione Edmund Mach, Via Mach 1, 38010 San Michele all'Adige, Italy; Centre for Analytical Chemistry, Department of Agrobiotechnology (IFA-Tulln), University of Natural Resources and Life Sciences, Vienna (BOKU), Konrad-Lorenz-Straße 20, 3430 Tulln an der Donau, Austria.
Department of Sustainable Ecosystems and Bioresources, Research and Innovation Centre, Fondazione Edmund Mach, Via Mach 1, 38010 San Michele all'Adige, Italy.
Microbiol Res. 2017 Aug;201:52-62. doi: 10.1016/j.micres.2017.04.015. Epub 2017 May 8.
Bacterial volatile organic compounds (VOCs) play important ecological roles in soil microbial interactions. Lysobacter spp. are key determinants of soil suppressiveness against phytopathogens and the production of non-volatile antimicrobial metabolites has been extensively characterised. However, the chemical composition and antagonistic properties of the Lysobacter volatilome have been poorly investigated. In this work, VOC emission profiles of four Lysobacter type strains grown on a sugar-rich and a protein-rich medium were analysed using solid-phase microextraction gas chromatography-mass spectrometry and proton transfer reaction-time of flight-mass spectrometry. Lysobacter antibioticus, L. capsici, L. enzymogenes and L. gummosus type strains were recognised according to their volatilome assessed using both headspace mass spectrometry methods Moreover, the chemical profiles and functional properties of the Lysobacter volatilome differed according to the growth medium, and a protein-rich substrate maximised the toxic effect of the four Lysobacter type strains against Phytophthora infestans. Antagonistic (pyrazines, pyrrole and decanal) and non-antagonistic (delta-hexalactone and ethanol) VOCs against Ph. infestans or putative plant growth stimulator compounds (acetoin and indole) were mainly emitted by Lysobacter type strains grown on protein- and sugar-rich media respectively. Thus nutrient availability under soil conditions could affect the aggressiveness of Lysobacter spp. and possibly optimise interactions of these bacterial species with the other soil inhabitants.
细菌挥发性有机化合物（VOCs）在土壤微生物相互作用中发挥着重要的生态作用。溶杆菌属细菌是土壤对植物病原体抑制作用的关键决定因素，其非挥发性抗菌代谢产物的产生已得到广泛研究。然而，溶杆菌挥发物组的化学成分和拮抗特性却鲜有研究。在这项研究中，我们使用固相微萃取气相色谱 - 质谱联用仪和质子转移反应飞行时间质谱仪，分析了在富含糖和富含蛋白质的培养基上生长的四株溶杆菌模式菌株的VOC排放谱。根据使用两种顶空气相质谱法评估的挥发物组，鉴定出了抗生溶杆菌、辣椒溶杆菌、产酶溶杆菌和黏性溶杆菌模式菌株。此外，溶杆菌挥发物组的化学谱和功能特性因生长培养基而异，富含蛋白质的底物使四株溶杆菌模式菌株对致病疫霉的毒性作用最大化。对致病疫霉具有拮抗作用的VOC（吡嗪、吡咯和癸醛）和无拮抗作用的VOC（δ - 己内酯和乙醇）或假定的植物生长刺激化合物（乙偶姻和吲哚），分别主要由在富含蛋白质和富含糖的培养基上生长的溶杆菌模式菌株释放。因此，土壤条件下的养分有效性可能会影响溶杆菌属细菌的侵袭力，并可能优化这些细菌与其他土壤生物的相互作用。
