Executive Summary : | Collective dynamics at the system's level have drawn attention for decades. How local interactions of individual components lead to self-organized orders in both temporal and spatial domains is a matter of quest. In this regard, as a canonical example of living soft matter, microbial systems are of great interest. Bacterial cells often self-organize collaboratively on various surfaces or interfaces, forming structurally complex patterned multicellular communities known as biofilms. Biofilm formation is a nearly universal trait in most of the bacteria in the natural environment aiming to perform certain physicochemical functions and to survive in advert conditions. Despite being a single-cell microorganism, bacteria display a significant morphological diversity ranging from spherical coccus to rigid rods to helical flexible elongated shapes. Variable cell morphology is the most common feature in natural microbial communities, such as cells of different shapes and sizes. Yet, very little about how the individual morphology affect the collective spatiotemporal organization at the community level is known. The second fascinating aspect of some bacteria is their inherent ability to propel themselves by harvesting the energy by action of their internal motor machinery. These microorganisms are categorized as living active matter and understanding the dynamics of these systems is an actively growing field nowadays in the scientific community. Bacterial self-propulsion provides an additional feature to the collective migration of cells in a colony. It might result in nontrivial spatiotemporal dynamics of multicellular microbial communities. A dense population of motile microorganisms are able to form remarkable collective behavior in the form of dynamic clusters moving in ordered and synchronized flow or vortices. Collective motions are ubiquitous in many biological processes to perform certain functions. The question is how and to what extent the collective cellular dynamics depend on the cell size, shape, or rather cellular morphology and their inherent modes of motility and the intracellular and extracellular environment. Here, the proposed theoretical and computational framework following continuum and particles-based modeling approaches will explore the collective spatiotemporal dynamics of a bacterial colony. In particular, the proposal would (a) decipher the complex interplay of cellular growth, division, physical forces, cell-motility and self-secreted EPS matrix in biofilm morphogenesis: swarming to biofilm transition and coexistence (b) underpin the physiological mechanisms and consequences of biofilm development at confined biotic surfaces such as human epithelial cells layers at intestine, (c) provide mechanistic insights of spatiotemporal dynamics of heterogeneous swarms concerning cell size variability and unravel the role of cell size and shape in mixed-species colonies in phase segregation. |