Modeling Combined Effects of Temperature and Structure on Competition and Growth of Multispecies Biofilms in Microbioreactors

Abstract

It is a well-known challenge to simulate competition and growth of multiple microorganisms in microbioreactors because of complex interactions among microorganisms, substrate, operational conditions, and structure. In this paper, we developed a multispecies thermal lattice Boltzmann model with the cellular automata model coupled to it to investigate competitive biofilm formation of two aerobic nitrite and ammonium oxidizers in a microbioreactor. Three configurations of the microbioreactor with two heating blocks were simulated to compare the combined effects of the structure and temperature on biofilm growth, detachment, and competition. The results revealed that the heating block temperatures and locations had lower effects on the biofilm growth rate and pattern than the inlet port temperature. Increasing temperature of inlet 2 has more effects on the biofilm growth than increasing temperatures of the two heating blocks. The percentage of the biofilm-occupied grids increases from 7.9 to 12.1% when the inlet temperature at inlet 2 increases from 10 to 50 °C. Two microorganisms showed different rates of responses to changing temperature and structure. The growth of the nitrite oxidizer was about 20% more than that of ammonium oxidizers. This model enables us to understand interactions between individual cells and biofilm communities in the microbioreactor.

The Origin of Niches and Species in the Bacterial World

“…An obvious corollary of the abovementioned “mirror metaphor” linking microbial individuals (from phyla to species and communities of species) and niches is that the taxonomic hierarchy of microbes should correspond to a hierarchy of niches, starting with those corresponding to the smaller microenvironments ( Baquero, 2009 ). However, the full characterization of the traits defining microenvironments remains in its infancy ( Baquero, 2015 ), although there has been significant methodological progress in recent years in this direction ( Wessel et al, 2013 ; Aghajani Delavar and Wang, 2020 ). There are macroniches that are likely exploited by organisms of higher hierarchies, as well as microniches resulting from microenvironments, where the microorganisms expand and evolve.…”

Phenol biodegradation in a bioreactor considering different geometries and process parameters

“…This LBM-CA platform has been used in authors' previous studies that dealt with biofilm growth and other important processes, such as microorganisms competition, 18,20 pH and temperature variation, 19,24 and dark and photo fermentation. 22,24 Priyadharshini and Bakthavatsalam 1 conducted experiments on phenol degradation in Erlenmeyer conical flasks of 1 L with a sample volume of 500 mL.…”

“…The biofilm growth is determined by 18–20 : where and are the inactivation coefficient and the biomass yield in reaction, respectively. In the LBM‐CA the local flow field and species concentration are calculated using LBM, then this data is used in CA to capture biofilm growth through several sub‐steps including microorganisms growth, detachment (due to shear stress, ), extra biomass transfer, and shrinkage.…”

Multispecies biofilms in fermentation: Biofilm formation, microbial interactions, and communication

“…The structure of biofilms is inhomogeneous, with individual cells living in different surrounding microenvironments, and it often plays a role in determining the future development and activities of biofilms (Zhao et al., 2016). There is a high degree of heterogeneity in metabolic activities, environmental fitness, responses to external and internal stresses, and gene expression of an individual species at different time scales of succession and in different locations in biofilms (Aghajani Delavar & Wang, 2020; W. Liu et al., 2019). Moreover, the spatial intermixing patterns of the two species and the cooperative interactions between them are often influenced by the presence of other strains in their surrounding environments (W. Liu et al., 2019).…”

“…During fermentation, especially semisolid fermentation, several variable factors, such as nutrient availability, pH, waste production, metabolites (ethanol, arginine, nitrite, etc. ), signaling molecules, hydrodynamic conditions, production, and storage conditions (temperature, oxygen, addition of nutrients, shear force, osmotic pressure, and antimicrobials) might lead to variations in microbial interactions and biofilm morphology and influence biofilm succession (Aghajani Delavar & Wang, 2020; Barathi et al., 2021; Donlan, 2002; Fang et al., 2021; Kolderman et al., 2015; Ratzke & Gore, 2018; Rivett et al., 2016; Stewart & Franklin, 2008).…”