التوصيف المظهري والجزيئي لعزلات الفطريات المرافقة للمكسرات والحبوب المنتجة لسم الافلاتوكسين B1 وامكانية توظيف بكتريا Bacillus subtilis في اختزال سميته

Rp.The Characterization Phenotypic and Molecular of Isolated Fungi Associated from Nuts and Grains That Produce Aflatoxin B1 and Possibility.. pdf

Abstract
Fungi are widely distributed, which causes spoilage of raw materials and food spoilage, in addition to their direct impact on human health via food chain toxins. The use of chemical pesticides and improper handling methods to eradicate fungi and limit their spread pose various hazards to health and the environment.
Therefore, the current research aims to find a safe and healthy alternative that is not harmful to the environment or organisms by using biological treatments that play an important role in biological control, as demonstrated by the results of the field study of showing crops in Karbala, where the Karbala government obtained 404 isolates of different types of fungi, including the fungal type Aspergillus
Aspergillus niger accounted for 98% of all inspected grains, when Aspergillus niger accounted for 90% of yellow corn grains, the appearance rate of other varieties was between 80 and 40%, and the appearance of the fungus Talaromys colombinus was very low 20 -50% Compared to the dominance of Aspergillus spp., the fungus Rhizopus microspore shows a 10–50% growth rate in the examined grain.
The results of thin-layer chromatography (TLC) detection and ammonia detection showed that all isolates produced different proportions of aflatoxin, and the most virulent strain was genetically diagnosed by PCR. The sequence results are sent to the Genome Bank and given a special sequence number because the isolates are 100% identical to isolates worldwide. This confirms its widespread distribution and that it is not restricted to specific environments.
On the other hand, the local soil provided a bacterial isolate with high inhibitory efficiency against fungi represented by Bacillus subtilis-type bacteria, and its diagnosis was confirmed externally and microscopically using a Vitec instrument because the isolate had no effect on the inhibitory The fungus grew very efficiently, around 100%, using a mix-and-match approach, and I named it Bacillus subtillus DB1.
A bacterial preparation was manufactured after the yellow corn medium proved highly efficient for the growth of bacteria, as the number of bacterial units reached12.5× 1012 CFU when it reached 7 ×1012 in the extract. Wheat was significantly less than barley extract.
Therefore, calcium carbonate was relied upon as a carrier for the bacteria at a rate of 1:2 g/ml (carrier/bacterial filtrate), as the calculated numbers of bacteria per gram were 1012×150 CFU/g, and a health safety check of the biological preparation was conducted on animals. rat. The laboratory and physiological blood tests and histological sections of the liver, kidney, and the first part of the intestine were within the normal limits, and no changes were seen from the normal condition compared to the treatment. control (untreated rats).
The biological preparation also proved to be highly efficient in the storage experiment, which lasted for six months, as no infections were recorded in the grains treated with the bacterial biological preparation only, compared with the control treatments, the untreated grains, where the concentration of the toxin in them, measured by HBLC technology, ranged between (98 and 96) PPM. Whereas, grains treated with Aspergillus flavus DB1 recorded a toxin contamination rate of 489.08 PPM, Talaromyces columbinus DB3 recorded a rate of 401.22 PPM, and a fungus called Rhizopus microsporum DB1 recorded a rate of 395.19 PPM.
When grains were treated with fungal inoculum and bacteria, the percent toxin concentration was zero for all treatments except for grains treated with A. flavus DB1 and bacteria, as it reached 1.99 PPM, which is very low compared to grains. Measuring toxin concentrations using HBLC techniques gave very accurate results for toxin presence compared to toxin concentrations in comparative treatments. Tanzyme activity has been demonstrated in bacteria. It is considered to be one of the most important enzymes for the inhibition of fungal growth and the destruction of aflatoxin toxins, since the enzyme can be isolated in purified form from bacterial extracts of liquid cultures aged for 48 hours by precipitation and dialysis methods. Because the enzyme is obtained in a 100% crude, purified form, and the cytotoxicity test of the pure enzyme is positive because the enzyme has no negative effect on red blood cells, it also demonstrates its efficiency in destroying aflatoxins because it will The aflatoxin concentration in the crude enzyme was reduced to 1.5 ng/ml, which was equivalent to 1.3 ng/ml in the purified enzyme.