Department of Biotechnology, Metropolitan Autonomous University, Iztapalapa, 09340, Mexico City, Mexico.
Department of Process Engineering and Hydraulics, Metropolitan Autonomous University, Iztapalapa, 09340, Mexico City, Mexico.
Curr Microbiol. 2022 Feb 12;79(4):99. doi: 10.1007/s00284-022-02761-4.
Mycotoxins may be present in nuts, coffee, cereals, and grapes, among other products. Increasing concerns about human health and environmental protection have driven the application of biological control techniques that can inhibit fungal contaminants. In this study, the growth inhibition of the ochratoxigenic fungus Aspergillus carbonarius Ac 162 was evaluated using 5 lactic acid bacteria (LAB). The LAB studied were Lactobacillus plantarum MZ801739 (J), Lactobacillus plantarum MZ809351 (31) and Lactobacillus plantarum MZ809350 (34), isolated in the Ivory Coast, and Lactobacillus plantarum MN982928 (3) and Leuconostoc citreum MZ801735 (23), isolated in Mexico. J, 31, 34, 3 and 23 are the internal strain codes from our laboratory. LAB were cultivated in De Man, Rogosa and Sharpe (MRS) broth, and different polyols (glycerol, mannitol, sorbitol, and xylitol) were added to the culture broth to stimulate the production of antifungal compounds. The fungal inhibition studies were performed using the poisoned food technique. The highest inhibition of A. carbonarius growth was obtained by cultivating L. plantarum MZ809351 in the presence of xylitol and glycerol. Under these conditions, 1 L of the L. plantarum MZ809351 cultures were used to identify antifungal compounds. The compounds were concentrated by solid-phase extraction and then characterized by GC-MS. In addition to 9-octadecenoic acid, 3 diketopiperazines or cyclic dipeptides were identified, including cyclo (Leu-Leu), cyclo (Pro-Gly) and cyclo (Val-Phe), which were compounds related to microbial antifungal activities. Xylitol and glycerol induced the production of these antifungal compounds against A. carbonarius Ac 162. On the other hand, adding xylitol and glycerol to the MRS broth reduced the Ochratoxin A (OTA) content to 56.8 and 54.7%, respectively. This study shows the potential for using L. plantarum MZ809351 as a biocontrol agent to prevent the growth of A. carbonarius and reduce the production of OTA in foods.
真菌毒素可能存在于坚果、咖啡、谷物和葡萄等产品中。人们对人类健康和环境保护日益关注，推动了生物防治技术的应用，该技术可以抑制真菌污染物。在这项研究中，使用 5 种乳酸菌（LAB）评估了产赭曲霉毒素的真菌 Aspergillus carbonarius Ac 162 的生长抑制情况。所研究的 LAB 是在科特迪瓦分离的植物乳杆菌 MZ801739（J）、植物乳杆菌 MZ809351（31）和植物乳杆菌 MZ809350（34），以及在墨西哥分离的植物乳杆菌 MN982928（3）和柠檬明串珠菌 MZ801735（23）。J、31、34、3 和 23 是我们实验室的内部菌株代码。LAB 在德曼、罗戈萨和夏普（MRS）肉汤中培养，并向培养液中添加不同的多元醇（甘油、甘露醇、山梨糖醇和木糖醇）以刺激抗真菌化合物的产生。使用有毒食物技术进行真菌抑制研究。在含有木糖醇和甘油的条件下，培养植物乳杆菌 MZ809351 可获得对 A. carbonarius 生长的最高抑制。在这些条件下，使用 1 L 的植物乳杆菌 MZ809351 培养物来鉴定抗真菌化合物。这些化合物通过固相萃取浓缩，然后通过 GC-MS 进行表征。除了 9-十八烯酸外，还鉴定出 3 种二酮哌嗪或环状二肽，包括环（亮氨酸-亮氨酸）、环（脯氨酸-甘氨酸）和环（缬氨酸-苯丙氨酸），它们是与微生物抗真菌活性相关的化合物。木糖醇和甘油诱导对 A. carbonarius Ac 162 产生这些抗真菌化合物。另一方面，向 MRS 肉汤中添加木糖醇和甘油可分别将赭曲霉毒素 A（OTA）的含量降低至 56.8%和 54.7%。这项研究表明，植物乳杆菌 MZ809351 有潜力作为生物防治剂，以防止 A. carbonarius 的生长并减少食品中 OTA 的产生。
