Intercepting signalling mechanism to control environmental biofouling

Abstract

Biofouling in environmental systems employs bacterial quorum sensing signals (autoinducers) and extracellular polymeric substances to onset the event. The present review has highlighted on the fundamental mechanisms behind biofilm formation over broad spectrum environmental niches especially membrane biofouling in water systems and consequent chances of pathogenic contamination leading to global economic loss. It has broadly discussed on bioelectrical signal (via, potassium gradient) and molecular signal (via, AHLs) mediated quorum sensing which help to propagate biofilm formation. The review has illustrated the potential of genomic intervention towards biofouled membrane microbial community and has uncovered possible features of biofilm microenvironment like quorum quenching bacteria, bioelectrical waves capture, siderophores arrest and surface modifications. Based on information, the concept of interception of quorum signals (AHLs) and bioelectrical signals (K⁺) by employing electro-modified (negative charges) membrane surface have been hypothesized in the present review to favour anti-biofouling.

Keywords: Bioelectrical wave; Genomic; Membrane biofouling; Quorum sensing; Siderophore.

Fig. 1

Graphical polynomial model presentation of last 10 years publication regarding membrane biofouling and biological insight into the phenomenon

Fig. 2

Schematic representation showing role of EPS in two niches, viz, bio-slimes on biofouled membrane (environmental biofilm) and in host tissues (pathogenic biofilm)

Fig. 3

Metagenomic analysis of biofouled membrane (MG-RAST ID 4585128.3) showing abundance, phylogenetic relation and co-existence of pathogenic bacteria with environmental isolates. Emerging pathogenic contaminants of biofouled membrane highlighted in ten groups

Fig. 4

Comparative distribution of biofilm and quorum signal-related genomic components in environmental and pathogenic bacterial genomes. 20 biofilm bacterial genomes were selected from environmental and pathogenic niches. 16 biofilm formers and 4 bacteria deficient in biofilm formation (stress mediated response)

Fig. 5

Schematic representation of proposed hypothesis for mitigating membrane biofouling: Graphics showing quorum sensing (biochemical + bioelectrical) coupled with the electro-modified negatively charged membrane surface delinks signals to mitigate biofouling. ‘A’ is the quorum producing biofilm bacteria which oscillates bioelectrical (K⁺) wave to generate signal to distant communities, i.e. B, C, D