{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,8]],"date-time":"2026-09-08T05:10:55Z","timestamp":1788844255717,"version":"build-2803163510"},"reference-count":46,"publisher":"MDPI AG","issue":"17","license":[{"start":{"date-parts":[[2026,9,6]],"date-time":"2026-09-06T00:00:00Z","timestamp":1788652800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Int. J. Mol. Sci.","IJMS"],"abstract":"<jats:p>Ochratoxin A (OTA) accumulation by Penicillium nordicum is enhanced at high salt concentrations. The genes involved in OTA biosynthesis include a polyketide synthase (PKS), although other PKSs outside the cluster could influence OTA production. This study aimed to evaluate a potential new PKS involved in OTA biosynthesis and the metabolites related to this mycotoxin. Optimised protocols were designed for the gene expression analysis of five genes that encoded the previously reported PKS to be overexpressed in dry-cured meat products (n2, n3, n4, n5 and n6). Their expression was tested in two P. nordicum strains (Pn15 and Pn856) grown in CYA medium with different salt concentrations. Fungal mycelia were used for gene expression analyses and metabolomics. Three genes (n3, n4 and n6) seem to be related to OTA biosynthesis in Pn856. However, n2 might be involved in OTA degradation. The lack of correlations between the genes studied and OTA in Pn15 could be due to the low OTA levels quantified. The metabolites coniferyl alcohol and 6-hydroxy-8-methoxy-3-methylisochroman were positively correlated to OTA, and 3-methylbutanoic acid and cephalosporolide E might be used as indicators to predict OTA. These results show the complex regulation and influence of PKS proteins on OTA levels.<\/jats:p>","DOI":"10.3390\/ijms27177933","type":"journal-article","created":{"date-parts":[[2026,9,7]],"date-time":"2026-09-07T13:53:28Z","timestamp":1788789208000},"page":"7933","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Unravelling the Role of Non-Clustered Polyketide Synthases and Key Metabolites in Ochratoxin a Accumulation by Penicillium nordicum in Salt-Rich Environments"],"prefix":"10.3390","volume":"27","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-0188-0399","authenticated-orcid":false,"given":"Micaela","family":"\u00c1lvarez","sequence":"first","affiliation":[{"name":"Secci\u00f3n Departamental de Nutrici\u00f3n y Ciencia de los Alimentos, Facultad de Veterinaria, Universidad Complutense de Madrid, 28040 Madrid, Spain"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"formal-analysis","vocabulary":"credit"},{"role":"investigation","vocabulary":"credit"},{"role":"methodology","vocabulary":"credit"},{"role":"data-curation","vocabulary":"credit"},{"role":"writing-original-draft","vocabulary":"credit"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2113-1830","authenticated-orcid":false,"given":"J\u00e9ssica","family":"Gil-Serna","sequence":"additional","affiliation":[{"name":"Departamento de Gen\u00e9tica, Fisiolog\u00eda y Microbiolog\u00eda, Facultad de Ciencias Biol\u00f3gicas, Universidad Complutense de Madrid, Jos\u00e9 Antonio Nov\u00e1is 12, 28040 Madrid, Spain"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"resources","vocabulary":"credit"},{"role":"supervision","vocabulary":"credit"},{"role":"conceptualization","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"}]},{"given":"Claudio","family":"Alba","sequence":"additional","affiliation":[{"name":"Secci\u00f3n Departamental de Nutrici\u00f3n y Ciencia de los Alimentos, Facultad de Veterinaria, Universidad Complutense de Madrid, 28040 Madrid, Spain"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"data-curation","vocabulary":"credit"},{"role":"methodology","vocabulary":"credit"},{"role":"software","vocabulary":"credit"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2392-2289","authenticated-orcid":false,"given":"Elia","family":"Roncero","sequence":"additional","affiliation":[{"name":"Higiene y Seguridad Alimentaria, Instituto Universitario de Investigaci\u00f3n de la Carne y Productos C\u00e1rnicos, Facultad de Veterinaria, Universidad de Extremadura, 10003 C\u00e1ceres, Spain"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"investigation","vocabulary":"credit"},{"role":"formal-analysis","vocabulary":"credit"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8568-9270","authenticated-orcid":false,"given":"Bel\u00e9n","family":"Pati\u00f1o","sequence":"additional","affiliation":[{"name":"Departamento de Gen\u00e9tica, Fisiolog\u00eda y Microbiolog\u00eda, Facultad de Ciencias Biol\u00f3gicas, Universidad Complutense de Madrid, Jos\u00e9 Antonio Nov\u00e1is 12, 28040 Madrid, Spain"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"funding-acquisition","vocabulary":"credit"},{"role":"resources","vocabulary":"credit"},{"role":"project-administration","vocabulary":"credit"},{"role":"supervision","vocabulary":"credit"},{"role":"conceptualization","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"}]}],"member":"1968","published-online":{"date-parts":[[2026,9,6]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"65","DOI":"10.1007\/s12550-016-0265-7","article-title":"Mycotoxins as human carcinogens\u2014The IARC Monographs classification","volume":"33","author":"Ostry","year":"2016","journal-title":"Mycotoxin Res."},{"key":"ref_2","first-page":"e06113","article-title":"Risk assessment of ochratoxin A in food","volume":"18","author":"Schrenk","year":"2020","journal-title":"EFSA J."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"233","DOI":"10.1016\/j.fm.2011.08.003","article-title":"The biosynthesis of ochratoxin A by Penicillium as one mechanism for adaptation to NaCl rich foods","volume":"29","author":"Graf","year":"2012","journal-title":"Food Microbiol."},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Wang, Y., Wang, L., Liu, F., Wang, Q., Selvaraj, J.N., Xing, F., Zhao, Y., and Liu, Y. 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