Table 3.

Biofilm mechanisms for adaptation to the media.

Property	Advantages	References
Localised gradients of nutrients, oxygen, pH, and quorum sensing molecules	As a result of biofilm heterogeneity, gradients are generated which provide multiple habitats in which microbial cells can establish, depending on their physiological requirements.	[45]
Tolerance to desiccation	EPS confer structural protection against dehydrated environments. Studies in bacterial biofilm confirm that bacteria overproduce EPS molecules in dry environments.	[46,47]
Intraspecies cooperation and metabolic cooperativity	Biofilms favour intraspecies cooperation producing microenvironments that favour growth conditions. For example, nutrient cycling (carbon, nitrogen, sulphur) confers new nutrient sources inside the biofilm.	[48]
Antimicrobial tolerance	Biofilm lifestyle allows microorganisms to develop tolerance to antimicrobial therapies. Matrix can hinder diffusion or inactivate antimicrobial agents.	[42,49,50]
Persister cells and dormant cells	In these stages microbial cells remain inside biofilms and lead to treatment failure.	[51]
Efflux pumps	Efflux pumps promote antifungal and antibiotic depletion from the biofilm.	[52,53]
Exchange of genetic material	Cell-to-cell contact improves horizontal gene transfer given the cell-to-cell contact environment.	[54]
Enzyme degradation	Biofilm accumulates derived and waste products from metabolic processes. Enzymatic activity can recycle these nonviable subtracts to viable nutrients and degradation of EPS for cell dispersal.	[45,55]
Sorption	The sorption effect provides nutrients, gases and other molecule exchange.	[56]