Establishment of low-carbon microbial network to enhance phenol removal in microbial electrochemical systems with whole process carbon source limitation

•Unification of limited carbon source in biofilm formation and pollutant removal.•MES with limited bioavailable carbon source was more active in phenol degradation.•Limited acetate stimulated enrichment of phenol-degrading microorganisms.•Low-carbon microbial network was established under carbon source constraint.•Whole process carbon source limitation was more suitable for wastewater treatment.