Periphytic Biofilm Formation on Natural and Artificial Substrates: Comparison of Microbial Compositions, Interactions, and Functions

Abstract

Periphytic biofilms have been widely used in wastewater purification and water ecological restoration, and artificial substrates have been progressively used for periphyton immobilisation to substitute natural substrates. However, there is insufficient knowledge regarding the interaction network structure and microbial functions in biofilm communities on artificial substrates, which are essential attribute affecting their applications in biofilm immobilisation. This study compared the community structure, co-occurrence network, and metabolic functions of bacterial and microeukaryotic periphytic biofilms during a 35-day indoor cultivation on artificial substrates, such as artificial carbon fibre (ACF) and polyvinyl chloride (PVC), and natural substrates, such as pebble and wood. Results demonstrated that different types of artificial substrates could affect the community composition and functional diversity of bacterial and microeukaryotic biofilms. The bacterial and microeukaryotic community on ACF and PVC showed significantly higher Simpson index compared to those on wood. Bacterial networks on artificial substrates were more complex than those on natural substrates, while the keystone species on natural substrates were more abundant, indicating that the bacterial communities on artificial substrates had stronger stability and resistance to external interference. Furthermore, the functional metabolic profiles predicted showed the abilities of bacterial communities to metabolise nitrogen and carbon sources colonised on artificial substrates were stronger than those on natural substrates. These findings demonstrated that artificial substrates could be special niches for microbial colonisation, possibly altering microbial compositions, interactions, and functions. Therefore, this study provides a powerful theoretical basis for choosing suitable artificial substrates for microbial aggregation and immobilisation technology.

Formation, Development, and Cross-Species Interactions in Biofilms

“…On artificial substrates (carbon fiber and polyvinyl chloride), bacterial network patterns are more complex than those formed on natural surfaces (pebble and wood). It is also reported that bacteria colonized on artificial substrates are more powerful in metabolizing nitrogen, carbon, and arsenic sources ( Miao et al, 2021 ). Therefore, the effects of different substrate types on the dynamics of biofilm community could attract more attention in the field of biofilm research.…”

The biofouling process: The science behind a valuable phenomenon for aquaculture

“…33 Although most materials are susceptible to biofouling, organic and hydrophobic substrates generate more pronounced fouling than inorganic and hydrophilic materials, 34 but some synthetic surfaces may promote higher diversity than natural ones. 35 However, the surface properties can also be affected by the molecular film. In this regard, the chemistry of many surfaces is affected by chemically active compounds dissolved in water, including proteins and carbohydrates, which adhere to surfaces and promote earlier biofouling phases, especially in aquaculture systems.…”

Molecular regulation of conditioning film formation and quorum quenching in sulfate reducing bacteria

“…This study summarized the favorable impact of low concentrations (1–10 mM) of natural substrates over high concentrations (~100 mM) in developing the conditioning film in the aquatic ecosystem. Miao et al (2021) have found chemo-heterotrophy as the most dominant biogeochemical cycle in the microbial world involved in conditioning film development on wood surfaces. Intact and fragmented conditioning films are reported for the Actinomycetes , Pseudomonas sp., and Rhodococcus sp.…”