Oslizlo A, Stefanic P, Vatovec S, Beigot Glaser S, Rupnik M, Mandic-Mulec I
Department of Food Science and Technology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia.
Microb Biotechnol. 2015 May;8(3):527-40. doi: 10.1111/1751-7915.12258. Epub 2015 Mar 10.
Bacillus subtilis is a widespread and diverse bacterium t exhibits a remarkable intraspecific diversity of the ComQXPA quorum-sensing (QS) system. This manifests in the existence of distinct communication groups (pherotypes) that can efficiently communicate within a group, but not between groups. Similar QS diversity was also found in other bacterial species, and its ecological and evolutionary meaning is still being explored. Here we further address the ComQXPA QS diversity among isolates from the tomato rhizoplane, a natural habitat of B. subtilis, where these bacteria likely exist in their vegetative form. Because this QS system regulates production of anti-pathogenic and biofilm-inducing substances such as surfactins, knowledge on cell-cell communication of this bacterium within rhizoplane is also important from the biocontrol perspective. We confirm the presence of pherotype diversity within B. subtilis strains isolated from a rhizoplane of a single plant. We also show that B. subtilis rhizoplane isolates show a remarkable diversity of surfactin production and potential plant growth promoting traits. Finally, we discover that effects of surfactin deletion on biofilm formation can be strain specific and unexpected in the light of current knowledge on its role it this process.
枯草芽孢杆菌是一种广泛存在且具有多样性的细菌，其群体感应（QS）系统ComQXPA在种内表现出显著的多样性。这表现为存在不同的通讯群体（信息素型），这些群体能在组内高效通讯，但组间不能。在其他细菌物种中也发现了类似的QS多样性，其生态和进化意义仍在探索中。在这里，我们进一步研究了来自番茄根际的分离株之间的ComQXPA QS多样性，番茄根际是枯草芽孢杆菌的自然栖息地，这些细菌可能以营养形式存在于此。由于这种QS系统调节抗病原和生物膜诱导物质如表面活性素的产生，从生物防治角度来看，了解这种细菌在根际内的细胞间通讯也很重要。我们证实了从单株植物根际分离的枯草芽孢杆菌菌株中存在信息素型多样性。我们还表明，枯草芽孢杆菌根际分离株在表面活性素产生和潜在促进植物生长特性方面表现出显著的多样性。最后，我们发现表面活性素缺失对生物膜形成的影响可能具有菌株特异性，并且根据目前对其在此过程中作用的了解，这种影响是出乎意料的。
