Antagonistic interactions are sufficient to explain self-assemblage of bacterial communities in a homogeneous environment: a computational modeling approach

Abstract

Most of the studies in Ecology have been devoted to analyzing the effects the environment has on individuals, populations, and communities, thus neglecting the effects of biotic interactions on the system dynamics. In the present work we study the structure of bacterial communities in the oligotrophic shallow water system of Churince, Cuatro Cienegas, Mexico. Since the physicochemical conditions of this water system are homogeneous and quite stable in time, it is an excellent candidate to study how biotic factors influence the structure of bacterial communities. In a previous study, the binary antagonistic interactions of 78 bacterial strains, isolated from Churince, were experimentally determined. We employ these data to develop a computer algorithm to simulate growth experiments in a cellular grid representing the pond. Remarkably, in our model, the dynamics of all the simulated bacterial populations is determined solely by antagonistic interactions. Our results indicate that all bacterial strains (even those that are antagonized by many other bacteria) survive in the long term, and that the underlying mechanism is the formation of bacterial community patches. Patches corresponding to less antagonistic and highly susceptible strains are consistently isolated from the highly-antagonistic bacterial colonies by patches of neutral strains. These results concur with the observed features of the bacterial community structure previously reported. Finally, we study how our findings depend on factors like initial population size, differential population growth rates, homogeneous population death rates, and enhanced bacterial diffusion.

Bacterial Communities: Interactions to Scale

“…A cell automata model was built using the observations from all possible pairwise interactions between the 78 strains. The model predicted high biodiversity with different strains occupying spatially segregated patches across the surface ( Zapién-Campos et al, 2015 ). The model also predicted that survival of weaker bacteria is dependent upon being shielded from aggressors by patches of a third bacterial strain ( Zapién-Campos et al, 2015 ).…”

“…The model predicted high biodiversity with different strains occupying spatially segregated patches across the surface ( Zapién-Campos et al, 2015 ). The model also predicted that survival of weaker bacteria is dependent upon being shielded from aggressors by patches of a third bacterial strain ( Zapién-Campos et al, 2015 ). This prediction is borne out in a model three species biofilm formed by isolates of soil bacteria.…”

Nutrient Dependent Cross-Kingdom Interactions: Fungi and Bacteria From an Oligotrophic Desert Oasis

“…Remarkably, prokaryotic diversity in this area has been shaped by oligotrophic conditions ( Bonilla-Rosso et al, 2012 ), developing several strategies to cope with low concentration of nutrients, in particular phosphorous ( Peimbert et al, 2012 ; Aguirre-von-Wobeser et al, 2014 ). Hence, bacterial interactions in these oligotrophic aquatic systems are epitomized by a notable resistance to antibiotics, leading to a fierce competition as observed during in situ mesocosm experiments ( Ponce-Soto et al, 2015 ), in a bacterial guild ( Pérez-Gutiérrez et al, 2013 ) and computational modeling ( Zapién-Campos et al, 2015 ). However, information on FBI cross-kingdom interactions is still unknown.…”

Antagonism and population dynamics of Acinetobacter baumannii from US military treatment centers

“…Antagonism is a widespread bacterial trait resulting from the production of diffusible inhibitory or antibiotic biochemicals (Abrudan et al, 2015;Al-Saedi, Stones, Vaz, & Krachler, 2016;Buffie & Pamer, 2013;Christensen et al, 2016;Cordero et al, 2012;Grossart, Schlingloff, Bernhard, Simon, & Brinkhoff, 2004;Hawlena, Bashey, & Lively, 2012;Zapien-Campos, Olmedo-Alvarez, & Santillan, 2015). The functional impact of antagonism on community ecology is debated, particularly with regard to whether antagonism is primarily a cooperative trait promoting population cohesion and synergy (Cordero et al, 2012), or a competitive trait used as a weapon against other microbes (Abrudan et al, 2015).…”