Recombinant AflQ: a novel fungal-derived protein with potent antibacterial properties

Mycotoxins, especially aflatoxins produced by fungi of the genus Aspergillus, threaten global food security and public health due to their carcinogenic and immunosuppressive effects. To exploit Key enzymatic steps in the aflatoxin biosynthetic pathway for therapeutic applications, the aflQ gene (also Known ordA) -wich encodes acytochrome P450 monooxygenase capable of generating reactive oxidative species -was targeted as a candidate antimicrobial agent. This study aims to extract and characterize the aflQ gene (known as ordA) from the Aspergillus niger fungus isolated from grain silos in Anbar Governorate, ands proteomically evaluate it as an innovative antimicrobial. The methodology involved isolating the fungus and molecularly characterizing it by amplifying and sequencing a segment ofthe18S rRNA gene. The species identity was confirmed utilizing the BLAST tool in the NCBI database. The sequence was deposited in GenBank and received an Accession number (PV455323). Subsequently, amplification of the aflQ gene was performed using polymerase chain reaction (PCR) and cloned into the pET-30b( +) expression vector. The hybrid plasmid was transformed into E. coli BL21 bacteria, and gene expression was induced using IPTG. The protein production was confirmed by SDS-PAGE analysis at the predicted molecular weight of 63-64 kDa. The results showed that the recombinant AflQ protein exhibited significantly enhanced inhibitory potency, with inhibition diameters reaching 24 mm against Gram-positive bacteria (Staphylococcus and Enterococcus) and 12.5 mm against Gram-negative bacteria (E. coli and K. pneumoniae). Conversely, the control bacterial culture showed no inhibitory activity, verifying that the observed efficacy specific to the AflQ protein. The study concludes that the AflQ protein represents a new class of oxidoreductase/Cytochrome P450antimicrobial agents. It highlights the significance of utilizing cellular debris to reduce industrial production costs by eliminating expensive purification steps.