Trans-kingdom interactions in mixed biofilm communities

Abstract

The microbial world represents a phenomenal diversity of microorganisms from different kingdoms of life which occupy an impressive set of ecological niches. Most, if not all, microorganisms once colonise a surface develop architecturally complex surface-adhered communities which we refer to as biofilms. They are embedded in polymeric structural scaffolds serve as a dynamic milieu for intercellular communication through physical and chemical signalling. Deciphering microbial ecology of biofilms in various natural or engineered settings has revealed co-existence of microorganisms from all domains of life, including Bacteria, Archaea and Eukarya. The coexistence of these dynamic microbes is not arbitrary, as a highly coordinated architectural setup and physiological complexity show ecological interdependence and myriads of underlying interactions. In this review, we describe how species from different kingdoms interact in biofilms and discuss the functional consequences of such interactions. We highlight metabolic advances of collaboration among species from different kingdoms, and advocate that these interactions are of great importance and need to be addressed in future research. Since trans-kingdom biofilms impact diverse contexts, ranging from complicated infections to efficient growth of plants, future knowledge within this field will be beneficial for medical microbiology, biotechnology, and our general understanding of microbial life in nature.

The Coexistence of Bacterial Species Restructures Biofilm Architecture and Increases Tolerance to Antimicrobial Agents

“…In addition, upregulation of glycosyltransferase genes may lead to increased catalysis of nucleotide sugars acting as activating monosaccharide donors in E. faecalis , resulting in the production of oligosaccharides/polysaccharides and their derivatives ( 48 ). This is similar to the increase in α glucan production caused by the glycosyltransferase GtfB secreted by S. mutans in the enhanced mixed-species biofilms formed by S. mutans and C. albicans ( 49 ). Moreover, RNA-seq of E. faecalis in dual-species biofilms ( E. faecalis + E. coli O157:H7) showed increased the expression of genes related to the PTS system and ABC transport system at 24 h (Table S8), indicating that E. faecalis may acquire increased access to more nutrients in dual/multispecies biofilms by regulating the expression of genes related to transport systems.…”

eDNA-stimulated cell dispersion fromCaulobacter crescentusbiofilms upon oxygen limitation is dependent on a toxin-antitoxin system

“…Does the PCD-stimulated cell dispersal mechanism we have described constitute cooperation and even altruism? Altruism mechanisms in biofilms have been discussed previously (Penesyan et al, 2021, Sadiq et al, 2021. Altruism involves a trade-off between growth rate and growth yield in the biofilm to preserve resources at the cost of individual growth rate for the fitness of the entire population (Kreft, 2004), or with the public goods that are used by the whole attached colony (Nadell et al, 2008).…”

Understanding bacterial biofilms: From definition to treatment strategies

“…Multiple biofilm infections may exhibit different antibiotic sensitivities. Although the specific details of bacterial interactions in numerous microorganisms are not yet precise, there are metabolic links and spatial organization among bacteria, which may result in quorum sensing and resistance gene transfer to produce more antibiotic-resistant biofilms (Røder et al, 2020;Sadiq et al, 2021).…”

“…Bacterial biofilms are communities of microorganisms derived from single or multiple bacterial strains. Compared with singlespecies biofilms, multi-species biofilms showed the following new characteristics through interspecies interactions: increased biofilm mass, increased community cell count, enhanced metabolic activity of community members, increased antimicrobial tolerance, and changes in spatial organization and structure (Sadiq et al, 2021). Multispecies biofilms exhibit new characteristics different from their floating state, resulting from competition or cooperation.…”