20.500.12556/RUL-177920 Valorisation of acid whey permeate for high-purity nisin Z production using artisanal Lactococcus lactis isolates The growing demand for sustainable bioprocessing has positioned whey, a side stream of the dairy industry, as a valuable substrate for producing high-value compounds. This study investigated the production and purification of nisin, a potent lantibiotic, using permeate (10 kDa cut-off ) of ultrafiltered acid whey (PUFAW) devoid of lactoferrin as growth medium. Three strains of Lactococcus lactis subsp. lactis, including two artisanal isolates (IM 143 and IM 145) and a reference strain (IM 407), were evaluated for nisin production in PUFAW supplemented with yeast extract (YE) and mineral salts. Strain IM 145 showed superior growth and antimicrobial activity in PUFAW with YE (30 g/L) and produced up to 51,200 BA/mL of nisin. The bacteriocin was purified by ammonium sulphate precipitation followed by preparative RP-HPLC, yielding a product with 79.2% chromatographic purity. Tricine-SDSPAGE and mass spectrometry confirmed the identity of the purified compound as nisin Z. This study presents a cost-effective, circular economy approach for the production of high-purity nisin from dairy side streams, with potential applications in food preservation and biomedicine. nisin Z bacteriocin acid whey permeate Lactococcus lactis RP-HPLC circular economy mlekarstvo kisla sirotka nizin Z Lactococcus lactis krožno gospodarstvo true false true Angleški jezik Slovenski jezik Članek v reviji 2026-01-13 12:38:22 2026-01-13 12:38:23 2026-01-14 04:26:32 0000-00-00 00:00:00 2026 0 0 10 str. article no. 9 Vol. 26 2026 0000-00-00 Zaloznikova Objavljeno apc 0000-00-00 0000-00-00 2025-11-25 637.1 1471-2180 10.1186/s12866-025-04543-x 259442947 RAZ_Liaqat_Humna_2026.pdf RAZ_Liaqat_Humna_2026.pdf 1 D3AE66EC735C348D705BB22CCF3C2EDA 620eb96e54d10ccb24026d2ce7e2712a5cd09777cf620e567557b173979204b1 93444309-f074-11f0-bf92-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=225345 https://link.springer.com/article/10.1186/s12866-025-04543-x 1 57703f95-f074-11f0-bf92-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=225344 Biotehniška fakulteta 0 0 0