Marine biofilms: diversity of communities and of chemical cues

Abstract

Summary Surfaces immersed in seawater are rapidly colonized by various microorganisms, resulting in the formation of heterogenic marine biofilms. These communities are known to influence the settlement of algae spores and invertebrate larvae, triggering a succession of fouling events, with significant environmental and economic impacts. This review covers recent research regarding the differences in composition of biofilms isolated from different artificial surface types and the influence of environmental factors on their formation. One particular phenomenon – bacterial quorum sensing (QS) – allows bacteria to coordinate swarming, biofilm formation among other phenomena. Some other marine biofilm chemical cues are believed to modulate the settlement and the succession of macrofouling organisms, and they are also reviewed here. Finally, since the formation of a marine biofilm is considered to be an initial, QS‐dependent step in the development of marine fouling events, QS inhibition is discussed on its potential as a tool for antibiofouling control in marine settings.

Microbial Colonization in Marine Environments: Overview of Current Knowledge and Emerging Research Topics

“…On the surface of glass slides deployed for up to 3 weeks at different water depths (5,10,20,40,80 and 160 m) in Loch Fyne, Clyde Sea, W Scotland, Head et al [58] using epifluorescence and bright field microscopy found a seasonal variability in the composition of microbial biofilm. In April, the biofilm community varied significantly with depth, although this effect was ascribable to changes in the diatom community.…”

“…These microbial structures include several levels of structural and functional complexity, which are continuously adapted to the environmental conditions of marine ecosystems. The physical structure, community composition and function of microbial biofilms are controlled by a wide range of physical, chemical and biological variables and processes [2,10], including environmental interactions, interactions with topography, nutrient and organic matter cycling, and photosynthesis. In turn, biofilms are able to influence ecosystem functioning ( Figure 1).…”

“…Marine biofilms have been the subject of many studies [2,4,[6][7][8]10]; the studies performed in this context have investigated both basic and applicative features, exploring key topics that cover microbial biofilm growth and structure, biofilm-substrate or -environment interactions, resistance of biofilms to antibiotics, microbial cell-to-cell signaling and biotechnological potential of biofilms (i.e., discovery of bioactive molecules/compounds, biofilm application in food, cosmetic, pharmaceutical, bioremediation and industrial fields). A schematic diagram of the main features in marine biofilm research is shown in Figure 2.…”

“…A schematic diagram of the main features in marine biofilm research is shown in Figure 2. Interest towards microbial biofilms depends not only on their detrimental effects in environmental and medical research (such as in the case of biofilm-related pipeline occlusion, or biofilms acting as a reservoir for antibiotic resistance, respectively) but also on their key role as mediators of substrate colonization and consequent implications in Interest towards microbial biofilms depends not only on their detrimental effects in environmental and medical research (such as in the case of biofilm-related pipeline occlusion, or biofilms acting as a reservoir for antibiotic resistance, respectively) but also on their key role as mediators of substrate colonization and consequent implications in several fields [3,4,10]. Moreover, in parallel with the emerging problem of plastic pollution, a plethora of studies have recently investigated in marine ecosystems the structure, composition and metabolic activities of the microbial communities colonizing the surface of plastic debris, belonging to the size classes of macro-and micro-plastics [13].…”

“…To date, some reviews available in the scientific literature have provided useful insights into different aspects of biofilm formation, structure, biological functions and their biotechnological perspectives [2,4,[6][7][8]10,22]. Some research questions, however, need to be further deepened, such as:…”