Generation of mycotoxin biosynthetic gene clusters deletion strains in the citric acid-hyperproducing Aspergillus lacticoffeatus WU-2020 by genome editing technique
Year: 2026
Type: article
Abstract: Aspergillus lacticoffeatus WU-2020 is a citric acid-hyperproducing filamentous fungus suitable for solid-state culture.This strain belongs to the Aspergillus section Nigri, which includes microorganisms categorized as Generally Recognized as Safe (GRAS) defined by the United States Food and Drug Administration (FDA).However, A. lacticoffeatus WU-2020 was confirmed to possess intact biosynthetic gene clusters for the mycotoxins ochratoxins and fumonisins and to produce these mycotoxins.Under citric acid production conditions, A. lacticoffeatus WU-2020 produced ochratoxin A, ochratoxin B and B-series fumonisins (fumonisin B 1 , fumonisin B 2 , and fumonisin B 3 ).To generate a safer citric acid-hyperproducing strain, ochratoxin and fumonisin biosynthetic gene clusters were deleted in A. lacticoffeatus WU-2020 using genome editing technique with Cas9 ribonucleoproteins (RNPs).The deletion strain obtained (WU-2020-Shin1) was confirmed to produce neither ochratoxins (ochratoxin A and ochratoxin B) nor B-series fumonisins (<1 μg/L).Additionally, strain WU-2020-Shin1 produced 101 g/L of citric acid (yield (the ratio of the amount of citric acid produced to that of glucose consumed): 72.7% wt/wt) in a semi-solid-state culture, comparable to the wild-type under the same conditions (citric acid production: 101 g/L; yield: 72.4% wt/wt).This study indicates that the ochratoxin and fumonisin biosynthetic gene clusters are not related to citric acid production.
Source: JSM Mycotoxins
DOI: 10.2520/myco.76-2-3
Language: English
Subfield: Plant Science
Domain: Life Sciences
SDG: Zero hunger
Open Access status: diamond
OpenAlex ID: W7204138251