Abstract : The majority of microbial life on Earth occurs in biofilms, heterogeneous microbial communities embedded in layers of a self-produced extracellular matrix. Biofilms have a detrimental role in industrial and medical applications, via antibiotic-resistant infections, corrosion and fouling. On the other hand, they are also widely used in bioremediation technologies to improve water quality and generate renewable resources. The non-linear, multidimensional and multiscale nature of these complex microbial systems provides ample opportunity for investigation with theoretical modeling. This minisymposium focuses on continuum deterministic models, and brings together different biofilm applications, modeling approaches, and methods for model analysis.
Organizer(s) : N.G. Cogan, Vincenzo Luongo, Maria Rosaria Mattei
02612 (1/2) : 4C @D514 [Chair: Maria Rosaria Mattei]
[04151] Bacterial Biofilms across scales and applications
Format : Online Talk on Zoom
Author(s) :
Nicholas Cogan (Florida State University)
Abstract : This talk will describe mathematical modeling of biofilm dynamics in general. This should set the stage for the talks in this session that include models that focus on the physics of fluids, materials, and biology. Applications range from environmental to engineering as well as scales from millimeters to meters and time scales that range from seconds to weeks. Because of the wide variety in scales and applications, mathematical aspects must be both flexible and precise. This tension has driven an explosion in interest in biofilm models in the past 30+ years and there are a handful of broadly studied models which will be discussed in this talk.
[03848] Simulation of ultrasonic biofilm detachment in membrane aerated bioreactors
Format : Online Talk on Zoom
Author(s) :
Maryam Ghasemi (University of Waterloo)
Sheng Chang (University of Guelph)
Sivabal Sivaloganathan (University of Waterloo)
Abstract : Controlling biofilm thickness in an aerated membrane biofilm reactor (MBfR) has been recognized as a key for MBfRs to achieve a long-term stable performance. In this context, acoustic cavitation is an effective strategy that can be used for controlling biofilm thickness. However, to maintain the biofilm thickness at an optimum value, it is necessary to understand the effect of acoustic parameters and cavitation bubble distribution on biofilm detachment and establish a link between biofilm detachment and regrowth. The purpose of this study is to provide an integrated mathematical model that describes biofilm development in an aerated membrane biofilm reactor using a nonlinear reaction-diffusion model and its response to mechanical stress generated from acoustic cavitation. The simulation results show that amplitude and frequency of transducer are two key factors that affect biofilm detachment. Moreover, uniform distribution of cavitation along the biofilm surface is critical to achieve an even biofilm thickness. Furthermore, periodic cavitation detachment with an appropriate resting time in between is important for maintaining the biofilm thickness at a desired value. Therefore, the proposed integrated modeling approach can be used to optimize acoustic cavitation parameters and achieve effective biofilm thickness control in MBfRs.
[04177] Microbially-influenced transport in sea ice
Format : Talk at Waseda University
Author(s) :
Isaac Klapper (Temple University)
Abstract : Sea ice, which covers a significant portion of the earth's surface, is an interestingly complicated material consisting of a mixture of solid ice and liquid brine phases which are coupled by thermodynamic considerations, It also is a platform for microbial life. A model will be presented that hypothesizes that, in turn, the sea ice resident microbial population
might impact ice sheet structure and, in particular, its transport properties including notably heat transport.
[04844] Computational simulations of biofouling on ship hulls
Format : Online Talk on Zoom
Author(s) :
Rosalind Allen (Friedrich Schiller University Jena)
Patrick Sinclair (University of Edinburgh)
Jennifer Longyear (AkzoNobel)
Kevin Reynolds (AkzoNobel)
Alistair Finnie (AkzoNobel)
Chris Brackley (University of Edinburgh)
Martin Carballo Pacheco (University of Edinburgh)
Abstract : We use computer simulations to investigate two coating technologies for ship hulls. Simulating microbial colonization of a surface that releases a biocidal chemical we find intrinsic stochasticity with an important role for immigration of biocide-resistant species. Further, computational fluid dynamics simulations of flow across a textured (riblet) surface show that removal of biofouling by flow may be ineffective if the flow is not well aligned. Simulations can help understand marine biofouling on advanced surface coatings.
[05492] Long time behaviour of a thin-film model for early biofilm development
Format : Talk at Waseda University
Author(s) :
John Ward (Loughborough University)
Abstract : We will present a model describing the interaction of a thin, surface growing biofilm and planktonic cells. Assuming the biofilm can be described as homogeneous, thin, highly viscous fluid, a coupled system of nonlinear reaction-diffusion equations is derived, one of which having a fourth-order ``diffusion'' term. Key results using numerical computation and asymptotic analysis will be presented that indicate the dominant processes in early biofilm expansion and the subtle complxities of the travelling wave solutions.
