Department of Biological Sciences, Halmos College of Natural Sciences and Oceanography, Nova Southeastern University, 3301 College Ave, Fort Lauderdale, Florida, 33314, USA.
Guy Harvey Oceanographic Center, Nova Southeastern University, 8000 North Ocean Dr, Dania Beach, Florida, 33004, USA.
Sci Rep. 2017 Mar 27;7(1):440. doi: 10.1038/s41598-017-00588-9.
Cooperation is fundamental to the survival of many bacterial species. Previous studies have shown that spatial structure can both promote and suppress cooperation. Most environments where bacteria are found are periodically disturbed, which can affect the spatial structure of the population. Despite the important role that spatial disturbances play in maintaining ecological relationships, it remains unclear as to how periodic spatial disturbances affect bacteria dependent on cooperation for survival. Here, we use bacteria engineered with a strong Allee effect to investigate how the frequency of periodic spatial disturbances affects cooperation. We show that at intermediate frequencies of spatial disturbance, the ability of the bacterial population to cooperate is perturbed. A mathematical model demonstrates that periodic spatial disturbance leads to a tradeoff between accessing an autoinducer and accessing nutrients, which determines the ability of the bacteria to cooperate. Based on this relationship, we alter the ability of the bacteria to access an autoinducer. We show that increased access to an autoinducer can enhance cooperation, but can also reduce ecological resistance, defined as the ability of a population to resist changes due to disturbance. Our results may have implications in maintaining stability of microbial communities and in the treatment of infectious diseases.
合作是许多细菌物种生存的基础。先前的研究表明，空间结构既可以促进合作，也可以抑制合作。大多数发现细菌的环境都会受到周期性的干扰，这会影响种群的空间结构。尽管空间干扰在维持生态关系方面起着重要作用，但目前尚不清楚周期性空间干扰如何影响依赖合作生存的细菌。在这里，我们使用具有强烈阿利效应的细菌来研究周期性空间干扰的频率如何影响合作。我们表明，在空间干扰的中间频率下，细菌种群的合作能力受到干扰。一个数学模型表明，周期性的空间干扰导致了对自体诱导物和营养物质的获取之间的权衡，这决定了细菌的合作能力。基于这种关系，我们改变了细菌获取自体诱导物的能力。我们表明，增加对自体诱导物的获取可以增强合作，但也会降低生态阻力，即种群抵抗由于干扰而发生变化的能力。我们的研究结果可能对维持微生物群落的稳定性和治疗传染病具有重要意义。
