The　development　of　tight　ultrafiltration　membranes　has　opened　new　avenues　for　the　fractionation　of　organics　and　inorganic　salts　from　highly　saline　organic-rich　wastewaters,　showing　great　potential　as　alternatives　to　nanofiltration　membranes　for　the　sustainable　recovery　of　high　value-added　products.　In　this　work,　polypeptidebased　antimicrobial　tight-ultrafiltration　membranes　were　developed　through　the　interfacial　polymerization　of　epsilon-polylysine　(epsilon-pl)　and　trimesoyl　chloride　(TMC)　on　porous　ultrafiltration　substrates　for　the　sustainable　management　of　highly　saline　textile　wastewater.　Systematic　characterization　was　conducted　to　demonstrate　the　formation　of　continuous,　thin　and　smooth　epsilon-pl/TMC　cross-linked　networks.　The　designed　tight　epsilon-pl/TMC　composite　ultrafiltration　membrane　with　a　MWCO　of　3185　Da　showed　exceptional　dye/salt　fractionation　performance　in　highly　saline　textile　wastewater,　achieving　＞99.80　%　rejection　for　various　dyes　(0.2　g　L-　1　direct　red　80,　reactive　black　5　or　reactive　blue　2)　and　a　＜3.35　%　salt　rejection　(20.0　g　L-　1　NaCl),　with　favorable　water　permeation　(39.13-44.46　L　m-　2　h-1　&　sdot;bar-　1).　In　addition,　the　long-term　stability　of　the　polypeptide-based　tight　ultrafiltration　membrane　was　confirmed　to　be　sufficient　for　enduring　dye/salt　separation.　Furthermore,　the　intercalation　of　epsilon-polylysine　onto　the　membrane　surface　strongly　enhanced　the　antibacterial　activity　(i.e.,　99.97　%　bacterial　inhibition)　of　the　tight　ultrafiltration　membranes.　This　competitive　performance　highlights　the　potential　of　tight　epsilon-pl/TMC　composite　ultrafiltration　membranes　for　the　sustainable　management　of　highly　saline　organic　wastewater.