The new article, published in npj Biofilms and Microbiomes, suggests that microbial aggregates - biofilms are unique life forms and have more similarities to plants and animals than previously thought.
With the field of biofilm research in its infancy, scientists investigating these cell aggregates now understand that the absolute majority of microbes do not exist as single, free-living cells. Instead, they live as tight communities of interconnected cells, known as biofilms.
“Biofilms are ever-present and play critical roles in both natural and human-made environments. As they form tight-knit communities, these microbes are important in ensuring the effective functioning of the ecosystems they thrive in,” says Dr Anahit Penesyan from the Department of Biological Sciences.
The new insight from Macquarie University research groups has shown that these elusive cell aggregates are far more complex than previously understood. The researchers present three differing perspectives into the lives of biofilms.
The first, and arguably the most traditional perspective, examines biofilms as collections of individual cells clumped together. “The single-cell-centric view arises from the century-old tradition of microbiology where microbes have been regarded as self-sufficient individuals that aggregate and temporarily adopt a sessile biofilm lifestyle,” says Dr Penesyan.
On the other hand, the ‘biofilm-centric’ view explored by researchers regards biofilms as a single entity, an individual organism comprised of many different cells that can communicate and perform coordinated functions that benefit the whole multicellular biofilm.
“Subsequently, the dispersal of single cells and cell aggregates from the biofilm can be regarded as a method of dissemination, similar to seeds or spores of traditional multicellular organisms,” says Dr Penesyan.
The researchers also propose a new, yet fundamental, characteristic of biofilms as incubators of cellular diversity in the microbial world.
“There is increasing evidence suggesting that the biofilm mode of growth promotes generation of diverse variants among biofilm cells. Biofilms are unique life forms as they create protective and relatively stable microenvironments for cells within to live and evolve” says Dr Penesyan.
The authors of the paper, entitled “Three faces of biofilms: a microbial lifestyle, a nascent multicellular organism, and an incubator for diversity”, believe these three varying perspectives are indeed complementary of each other – rather than mutually exclusive.
“The more we delve into investigating biofilms, the more we appreciate just how much we have yet to find out about the biofilm lifestyle. Only by examining biofilms using a holistic, multifaceted approach, researchers in this field can gain a better insight into this unique mode of life,” says Dr Penesyan.