Abstract:
The Aspergillus niger is a versatile filamentous fungus which has a wide range of industrial applications such as in biofuels (bio-refinery), food & beverages, textile, agriculture, paper & pulp, animal feed, detergents, pharmaceuticals. It is considered mostly safe and has GRAS status i.e. Generally Recognized as Safe. Recent reports are suggesting that the Aspergillus niger strains used for various industrial applications can also be the producer of mycotoxins (toxic secondary metabolites) mainly Fumonisins and Ochratoxins. A variety of food and feed stuffs are being contaminated by mycotoxins that includes cereals (such as corn, rye, soybean, wheat, sorghum, rice, spices, nuts, barley), animal products (such as meat, dairy products, eggs) and beverages. Among mycotoxins, ochratoxin A (OTA) has been implicated in a diverse range of toxicological effects in both animals and humans, that may include renal toxicity, mutagenicity, teratogenicity, neurotoxicity, and immunotoxicity. A cluster of genes having ota1, ota2, ota3, ota4 and ota5 is involved in the production of ochratoxin A in A. niger. In the lastdecade, CRISPR-Cas9 genome engineering has emerged as a powerful genome editing tool for various organisms including bacteria, yeasts, molds, plants, and humans. The system provides the flexibility to alter the genome with ease and high specificity either through gene knockout or through single or multiple gene integrations. In the current study, the CRISPR-Cas9 genome editing system has been optimized to engineer the genome of Aspergillus niger for the inhibition of ochratoxins biosynthesis by targeting its transcriptional factor. Cas9 based vector consisting of codon optimized Cas9 gene for A. niger was used. Motif specific gRNA for transcriptional factorgene was designed and transformed into A. niger protoplasts. The mutants generated were no longer able to produce ochratoxin A, validating the key role of targeted genein Ochratoxin A biosynthesis. Such atoxigenicA. niger strain can be used as a bio-competitor for mycotoxigenic strains of A. niger. Moreover, mycoproteins (fungal proteins) produced by such atoxigenic fungus on agro-industrial bio-products can be a potential protein source of good nutritive value for animal and poultry feed supplementation.
Page(s):
93-93
DOI:
DOI not available
Published:
Journal: Abstract Book on International Conference on Food and Applied Sciences (ICFAS-23) 3-5 August 23, Volume: 0, Issue: 0, Year: 2023
Keywords:
Aspergillus niger
,
CRISPRCas9
,
genome editing
,
Transcriptional Factor
,
Ochratoxins