Kovač Tihomir, Šarkanj Bojan, Klapec Tomislav, Borišev Ivana, Kovač Marija, Nevistić Ante, Strelec Ivica
Department of Applied Chemistry and Ecology, Faculty of Food Technology, Josip Juraj Strossmayer University of Osijek, Franje Kuhača 20, 31000, Osijek, Croatia.
Department of Chemistry, Biochemistry and Environmental Protection, Faculty of Sciences, University of Novi Sad, Trg Dositeja Obradovića 3, 21000, Novi Sad, Serbia.
AMB Express. 2018 Feb 5;8(1):14. doi: 10.1186/s13568-018-0544-0.
Increased interest in fullerene C and derivatives in recent years implies an intensification of their environmental spread. Yet, the potential risks for living organisms are largely unknown, including the interaction of C with fungal organisms. This may be especially relevant for mycotoxigenic fungi since C may both scavenge and produce reactive oxygen species (ROS), and oxidative stress induces mycotoxin production in fungi. Therefore, this study examined effects of environmentally plausible concentrations of C (0, 10, 50, and 100 ng/mL) on Aspergillus flavus growth and aflatoxin production in culture media. In addition, ROS-dependent oxidative stress biomarkers-thiobarbituric acid reactive substances (TBARS), reduced and oxidised glutathione ratio, superoxide dismutase isoenzymes, catalase, glutathione peroxidase, and glutathione reductase were determined in mycelia. Nanoparticles of fullerene C (nC) did not exhibit strong antifungal activity against A. flavus. At the same time, nC caused an antiaflatoxigenic effect at 10-100 ng/mL, and 50 ng/mL unexpectedly enhanced aflatoxin production. The TBARS content, reduced and oxidised glutathione ratio, and copper, zinc superoxide dismutase activity suggest that 10 ng/mL nC exerted antioxidative action and reduced aflatoxin B1 production within fungal cells. Detected prooxidative effects of 50 ng/mL fullerene exceeded cellular defenses and consequently enhanced aflatoxin B1 production. Finally, the results obtained with 100 ng/mL nC point to prooxidative effects, but the absence of increase in aflatoxin output may indicate additional, presumably cytotoxic effects of nC. Thus, a range of rather low levels of nC in the environment has a potential to modify aflatoxin production in A. flavus. Due to possible implications, further studies should test these results in environmental conditions.
近年来，人们对富勒烯C及其衍生物的兴趣增加，这意味着它们在环境中的扩散加剧。然而，其对生物体的潜在风险在很大程度上尚不清楚，包括C与真菌生物体的相互作用。这对于产毒真菌可能尤为重要，因为C既可以清除也可以产生活性氧（ROS），而氧化应激会诱导真菌产生霉菌毒素。因此，本研究考察了环境中合理浓度的C（0、10、50和100 ng/mL）对黄曲霉生长及培养基中黄曲霉毒素产生的影响。此外，还测定了菌丝体中依赖ROS的氧化应激生物标志物——硫代巴比妥酸反应性物质（TBARS）、还原型和氧化型谷胱甘肽比率、超氧化物歧化酶同工酶、过氧化氢酶、谷胱甘肽过氧化物酶和谷胱甘肽还原酶。富勒烯C纳米颗粒（nC）对黄曲霉未表现出强烈的抗真菌活性。同时，nC在10 - 100 ng/mL时产生了抗黄曲霉毒素作用，而50 ng/mL时意外地提高了黄曲霉毒素的产量。TBARS含量、还原型和氧化型谷胱甘肽比率以及铜、锌超氧化物歧化酶活性表明，10 ng/mL的nC发挥了抗氧化作用并降低了真菌细胞内黄曲霉毒素B1的产生。检测到50 ng/mL富勒烯的促氧化作用超过了细胞防御能力，因此提高了黄曲霉毒素B1的产量。最后，100 ng/mL nC的结果表明存在促氧化作用，但黄曲霉毒素产量未增加可能表明nC具有额外的、可能的细胞毒性作用。因此，环境中一系列相当低水平的nC有可能改变黄曲霉中黄曲霉毒素的产生。鉴于可能产生的影响，进一步的研究应在环境条件下验证这些结果。
