Bacteriophage therapy for membrane biofouling in membrane bioreactors and antibiotic-resistant bacterial biofilms

To demonstrate elimination of bacterial biofilm on membranes to represent wastewater treatment as well as biofilm formed by antibiotic-resistant bacterial (ARB) to signify medical application,anantibiotic-resistantbacteriumanditslyticbacteriophage were isolated from a full-scale wastewater treatment plant. Based on gram staining and complete 16S rDNA sequencing, the isolated bacterium showed a more than 99% homology with Delftia tsuruhatensis,agram-negativebacteriumbelongingtob-proteobacteria. The Delftia lytic phage's draft genome revealed the phage to be an N4- likephagewith59.7%G þCcontent.NotransferRNAsweredetectedfor the phage suggesting that the phage is highly adapted to its host Delftia tsuruhatensis ARB-1 with regard to codon usage, and does not require additional tRNAs of its own. The gene annotation of the Delftia lytic phage foundthree differentcomponents of RNApolymerase (RNAP) in thegenome,whichisatypicalcharacteristicofN4-likephages.Thelytic phage specifi ct oD. tsuruhatensis ARB-1 could successfully remove the biofilm formed by it on a glass slide. The water flux through the membrane of a prototype lab-scale membrane bioreactor decreased from47L/hm 2 to � 15L/hm 2 over4days duetoabiofilmformedbyD. tsuruhatensisARB-1. However, the flux increasedto 70% of the original after the lytic phage application. Overall, this research demonstrated phage therapy's great potential to solve the problem of membrane biofouling, as well as the problems posed by pathogenic biofilms in external wounds and on medical instruments. Biotechnol. Bioeng. 2015;9999: 1-11.