Jayashree T, Subramanyam C
Department of Biochemistry, University College of Science, Osmania University, Hyderabad, India.
Free Radic Biol Med. 2000 Nov 15;29(10):981-5. doi: 10.1016/s0891-5849(00)00398-1.
The relevance of free radical generation and oxidative stress with regard to aflatoxin production was examined by comparing the oxygen requirement and antioxidant status of a toxigenic strain of Aspergillus parasiticus with that of a nontoxigenic strain at early (trophophase) and late logarithmic (idiophase) growth phases. In comparison to the nontoxigenic strain, wherein the oxygen requirements were relatively unaltered at various growth phases, the toxigenic strain exhibited greater oxygen requirements at trophophase coinciding with onset of aflatoxin production. The activities of antioxidant enzymes such as xanthine oxidase, superoxide dismutase, and glutathione peroxidase and the mycelial contents of thiobarbituric acid-reactive substances as well as of reduced glutathione were all enhanced during the progression of toxigenic strain from trophophase to idiophase. The combined results suggest that aflatoxin production by the toxigenic strain may be a consequence of increased oxidative stress leading to enhanced lipid peroxidation and free radical generation.
通过比较寄生曲霉产毒菌株与非产毒菌株在早期（营养生长期）和对数后期（静止期）生长阶段的需氧量和抗氧化状态，研究了自由基生成和氧化应激与黄曲霉毒素产生的相关性。与非产毒菌株相比，非产毒菌株在不同生长阶段的需氧量相对不变，而产毒菌株在与黄曲霉毒素产生开始同时的营养生长期表现出更高的需氧量。在产毒菌株从营养生长期到静止期的过程中，抗氧化酶如黄嘌呤氧化酶、超氧化物歧化酶和谷胱甘肽过氧化物酶的活性以及丙二醛反应性物质和还原型谷胱甘肽的菌丝体含量均增加。综合结果表明，产毒菌株产生黄曲霉毒素可能是氧化应激增加导致脂质过氧化和自由基生成增强的结果。
