Valorisation of acid whey permeate for high-purity nisin Z production using artisanal Lactococcus lactis isolates

Liaqat, Humna (author), Paveljšek, Diana (author), Oberčkal, Jernej (author), Bogovič Matijašić, Bojana (author)

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.

• Language: English
• Keywords: nisin Z, bacteriocin, acid whey permeate, Lactococcus lactis, RP-HPLC, circular economy
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: BF - Biotechnical Faculty
• Publication status: Published
• Publication version: Version of Record
• Publication date: 25.11.2025
• Year: 2026
• Number of pages: 10 str.
• Numbering: Vol. 26, article no. 9
• PID: 20.500.12556/RUL-177920
• UDC: 637.1
• ISSN on article: 1471-2180
• DOI: 10.1186/s12866-025-04543-x
• COBISS.SI-ID: 259442947
• Publication date in RUL: 13.01.2026

Record is a part of a journal

• Title: BMC microbiology
• Shortened title: BMC Microbiol
• Publisher: BioMed Central
• ISSN: 1471-2180
• COBISS.SI-ID: 2441492

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.

Secondary language

• Language: Slovenian
• Keywords: mlekarstvo, kisla sirotka, nizin Z, Lactococcus lactis, krožno gospodarstvo

Projects

• Funder: ARIS - Slovenian Research and Innovation Agency
• Project number: P4-0097
• Name: Prehrana in mikrobna ekologija prebavil

• Funder: Other - Other funder or multiple funders
• Name: LIFE for Acid Whey