Abstract:
Acute stunting in children, liver cancer, and death often occur due to human exposure to aflatoxins in food. The severity of aflatoxin contamination depends on the type of Aspergillus fungus infecting the crops. In this study, Aspergillus species were isolated from households’ staple foods and were characterized for different aflatoxin chemotypes. The non-aflatoxigenic chemotypes were evaluated for their ability to reduce aflatoxin levels produced by aflatoxigenic A. flavus strains on maize grains. Aspergillus flavus (63%), A. tamarii (14%), and A. niger (23%) were the main species present. The A. flavus species included isolates that predominantly produced aflatoxins B1 and B2, with most isolates producing a high amount (>20 ug/µL) of aflatoxin B1 (AFB1), and a marginal proportion of them also producing G aflatoxins with a higher level of aflatoxin G1 (AFG1) than AFB1. Some non-aflatoxigenic A. tamarii demonstrated a strong ability to reduce the level of AFB1 by more than 95% when co-inoculated with aflatoxigenic A. flavus. Therefore, field evaluation of both non-aflatoxigenic A. flavus and A. tamarii would be an important step toward developing biocontrol agents for mitigating field contamination of crops with aflatoxins in Uganda.
摘要:
儿童急性发育迟缓,肝癌,人类经常接触食物中的黄曲霉毒素而导致死亡。黄曲霉毒素污染的严重程度取决于感染作物的曲霉属真菌的类型。在这项研究中,从家庭的主食中分离出曲霉属,并具有不同的黄曲霉毒素化学型。评估了非黄曲霉毒素化学型降低玉米籽粒上黄曲霉毒素菌株产生的黄曲霉毒素水平的能力。黄曲霉(63%),A.tamarii(14%),黑曲霉(23%)是存在的主要物种。黄曲霉属物种包括主要产生黄曲霉毒素B1和B2的分离株,大多数分离株产生大量(>20ug/µL)黄曲霉毒素B1(AFB1),并且它们中的一小部分还产生G黄曲霉毒素,其黄曲霉毒素G1(AFG1)的水平高于AFB1。当与黄曲霉毒素A.flavus共同接种时,一些非黄曲霉毒素A.tamarii表现出将AFB1水平降低95%以上的强大能力。因此,对非黄曲霉毒素A.flavus和A.tamarii的田间评估将是开发生物防治剂的重要一步,以减轻乌干达黄曲霉毒素对作物的田间污染。