Комплексная эколого-геохимическая оценка состояния природной среды на территории г. Горняк (Алтайский край)

Объектом исследования является территория г. Горняк (Алтайский край). Предметом исследования являются компоненты природной среды (волосы, накипь, почва, материал хвостохранилищ и листья тополя). Цель работы – изучить элементный состав природной среды и организма человека на территории г. Горняк (Алтайский край).The object of the study is the territory of the town of Gornyak (Altai Territory). The subject of the study is the components of the natural environment (hair, scale, soil, tailings material and poplar leaves). The purpose of the work is to study the elemental composition of the natural environment and the human body in the city of Gornyak (Altai Territory)

Isolation of Bacillus spp. from Thai fermented soybean (Thua-nao): screening for aflatoxin B1 and ochratoxin A detoxification.

Aims: To study the interaction between Bacillus spp. and contaminating Aspergillus flavus isolated strains from Thai fermented soybean in order to limit aflatoxin production. To study the detoxification of aflatoxin B1 (AFB1) and ochratoxin A (OTA) by Bacillus spp. in order to find an efficient strain to remove these toxins. Methods and Results: One A. flavus aflatoxin-producing strain and 23 isolates of Bacillus spp. were isolated from soybean and fresh Thua-nao collected from the north of Thailand. Inhibition studies of A. flavus and A. westerdijkiae NRRL 3174 (reference strain) growth by all isolates of Bacillus spp. were conducted by dual culture technique on agar plates. These isolates were also tested for AFB1 and OTA detoxification ability on both solid and liquid media. Most of the strains were able to detoxify aflatoxin but only some of them could detoxify OTA. Conclusions: One Bacillus strain was able to inhibit growth of both Aspergillus strains and to remove both mycotoxins (decrease of 74% of AFB1 and 92·5% of OTA). It was identified by ITS sequencing as Bacillus licheniformis. The OTA decrease was due to degradation in OTα. Another Bacillus strain inhibiting both Aspergillus growth and detoxifying 85% of AFB1 was identified as B. subtilis. AFB1 decrease has not been correlated to appearance of a degradation product. Significance and Impact of the Study: The possibility to reduce AFB1 level by a strain from the natural flora is of great interest for the control of the quality of fermented soybean. Moreover, the same strain could be a source of efficient enzyme for OTA degradation in other food or feeds