Isolation and identification of fungi contaminated with some local and imported chips and the possibility of controlling one of the toxin-producing fungi by using pleurotus ostreatusFiltrate and Sodiumbicarbonate treatments

Abstract

Samples of chips were collected from the markets and shops of the center and districts of Al-Diwaniyah Governorate for the period from (October - November 2021) and several types of fungi were isolated, Aspergillus niger , A.flavus, A.parasiticus, Aspergillus sp1,Aspergillus sp2,Aspergillus terreus,Mucor, Penicillium natatum and Rhizopus stolanifer. The results of the HPLC technique showed that the highest concentration of Aflatoxin B1 toxin was due to the filterate of Aspergillus terreus isolate of the chips sample, which amounted to 193.9 ppb, and this isolate was phenotypically diagnosed using taxonomic keys as well as molecularly diagnosed by polymerase chain reaction (PCR) technique in addition to base sequence analysis phylogenetic tree analysis for the purpose of comparing the isolate of the contaminated fungus A.terreus with the isolates previously registered in the National Center for Biotechnology Information (NCBI). Pleurotus.ostreatus filtrate and sodium bicarbonate proved their inhibitory ability for both radial growth and dry weight of the contaminated fungus isolate, where the highest inhibition rate reached64.44% for radial growth at 30% concentration to treat the interaction between P.ostreatus filtrate and sodium bicarbonate, while the highest inhibition rate was 57.03% for dry weight at 30% for same treat.