Zhang Jian, Zhu Liuyang, Chen Haoyu, Li Min, Zhu Xiaojuan, Gao Qiang, Wang Depei, Zhang Ying
Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin University of Science and Technology , Tianjin 300457, China.
Tianjin SF-Bio Industrial Bio-Tec Co., Ltd. , Tianjin 300462, China.
J Agric Food Chem. 2016 Dec 28;64(51):9680-9688. doi: 10.1021/acs.jafc.6b03907. Epub 2016 Dec 13.
The polyketide synthase gene An15g07920 was known in Aspergillus niger CBS 513.88 as putatively involved in the production of ochratoxin A (OTA). Genome resequencing analysis revealed that the gene An15g07920 is also present in the ochratoxin-producing A. niger strain 1062. Disruption of An15g07920 in A. niger 1062 removed its capacity to biosynthesize ochratoxin β (OTβ), ochratoxin α (OTα), and OTA. These results indicate that the polyketide synthase encoded by An15g07920 is a crucial player in the biosynthesis of OTA, in the pathway prior to the phenylalanine ligation step. The gene An15g07920 reached its maximum transcription level before OTA accumulation reached its highest level, confirming that gene transcription precedes OTA production. These findings will not only help explain the mechanism of OTA production in A. niger but also provide necessary information for the development of effective diagnostic, preventive, and control strategies to reduce the risk of OTA contamination in foods.
聚酮合酶基因An15g07920在黑曲霉CBS 513.88中被认为可能参与赭曲霉毒素A（OTA）的产生。基因组重测序分析表明，该基因An15g07920也存在于产赭曲霉毒素的黑曲霉菌株1062中。破坏黑曲霉1062中的An15g07920会消除其生物合成赭曲霉毒素β（OTβ）、赭曲霉毒素α（OTα）和OTA的能力。这些结果表明，由An15g07920编码的聚酮合酶是OTA生物合成中苯丙氨酸连接步骤之前途径中的关键参与者。基因An15g07920在OTA积累达到最高水平之前达到其最大转录水平，证实基因转录先于OTA产生。这些发现不仅有助于解释黑曲霉中OTA产生的机制，还为制定有效的诊断、预防和控制策略以降低食品中OTA污染风险提供必要信息。
