Prevalence of Secondary Metabolites Target Carcinogenic Clusters in the Circular DNA Sequence of Aspergillus salvadorensis to Aflatoxins

Abstract

The aim of this study was to determine the prevalence of precursor cancer cluster genes in the species A. salvadorensis, using the database sequenced by MACROGEN INC Kore del Sur by the circular DNA sequencing method by Illumina of the Metagenome Shotgun Sequencing (NGS) method design of 67M spots, 9.9G bases and 4.3Gb. The following method was used: MetaPhlAn4, where all the genetic information that the identified microorganisms may have was collected through a validated database and for the genes that are not in the database it was translated into protein sequences and compared with a protein database such as UniRef90, although they do not identify anticancer molecules, only precursor genes, this is done by laboratory methods such as HPLC or ELISA. Being carried out in the microbiology laboratories of the Faculty of Medicine and in MACROGEN INC of South Korea. Bioinformatics programs BLAST, CLUSTAL, GENBANK, M11, UGENE, T-COFEE including PYTHON were used. Human subjects were not used in the research. The seed lots were subjected to an ultraviolet (UV) light analysis. This qualitative, simple and fast laboratory method served as a first approximation to identify the possible presence of Aflatoxins which was later confirmed with gene analysis in sequencing. The analysis focused on searching for key genes within the aflatoxin cluster, such as aflC, aflD, aflR and aflS. In our study, the prevalence in the circular DNA chain positive for aflatoxins was negative and if it is negative, does not refer to toxicity, the prevalence would be zero. The use of ultraviolet light to determine aflatoxins is suggestive to find sufficient quantities present in the seeds, possibly used to identify contaminants to fungi. Of the most common species of the genus Aspegillus that produce aflatoxins are: A. flavus, A. pararasiticus, A. nomius, A. ochraceus, A. wentii in optimal conditions of temperature and humidity. The species A. salvadorensis does not have the capacity to produce aflatoxins in toxic doses and does not present carcinogenic aflatoxins according to the report of Macrogen Inc.2025 "gene family UniRef90_M2YIY2: Dothistromin biosynthesis regulatory protein aflR, UniRef90_O42716: Aflatoxin cluster transcriptional coactivator aflS genes related to aflatoxin were not detected". The prevalence is zero. Aflatoxins are chemical toxins produced by certain fungi, not by genetic sequences. What the report refers to is that no toxins were found in the sequence. Therefore, if the genes are missing, the fungus cannot produce the toxin.