Laboratory of Microbial Biomolecules, Department of Biochemical and Pharmaceutical Technology, University of São Paulo, 05508-000 São Paulo, Brazil; Centre for Healthy Eating and Food Innovation (HEFI), Faculty of Science and Engineering, Maastricht University - campus Venlo, Villafloraweg 1, 5928 SZ Venlo, the Netherlands.
Laboratory of Microbial Biomolecules, Department of Biochemical and Pharmaceutical Technology, University of São Paulo, 05508-000 São Paulo, Brazil.
Int J Food Microbiol. 2023 Nov 16;405:110337. doi: 10.1016/j.ijfoodmicro.2023.110337. Epub 2023 Jul 23.
The present study offers detailed insights into the antifungal and anti-mycotoxigenic potential of a biofilm forming lactic acid bacterium (Pediococcus pentosaceus) against one atoxigenic (Aspergillus flavus) and two toxigenic (Aspergillus nomius and Fusarium verticillioides) fungal strains. The antifungal effect of P. pentosaceus LBM18 strain was initially investigated through comparative analysis of fungi physiology by macroscopic visual evaluations and scanning electron microscopy examinations. The effects over fungal growth rate and asexual sporulation were additionally accessed. Furthermore, analytical evaluations of mycotoxin production were carried out by HPLC-MS/MS to provide insights on the bacterial anti-mycotoxigenic activity over fungal production of the aflatoxins B1, B2, G1 and G2 as well as fumonisins B1 and B2. Finally, reverse transcription quantitative real-time PCR (RT-qPCR) analysis was employed at the most effective bacterial inoculant concentration to evaluate, at the molecular level, the down-regulation of genes aflR, aflQ and aflD, related to the biosynthesis of aflatoxins by the strain of Aspergillus nomius. The effects over mycotoxin contamination were thought to be result of a combination of several biotic and abiotic factors, such as interaction between living beings and physical-chemical aspects of the environment, respectively. Several possible mechanisms of action were addressed along with potentially deleterious effects ascribing from P. pentosaceus misuse as biopesticide, emphasizing the importance of evaluating lactic acid bacteria safety in new applications, concentrations, and exposure scenarios.
本研究深入探讨了一种形成生物膜的乳酸细菌（戊糖片球菌）对一株非产毒真菌（黄曲霉）和两株产毒真菌（棒曲霉和串珠镰刀菌）的抗真菌和抗产毒潜力。首先通过宏观视觉评估和扫描电子显微镜检查对戊糖片球菌 LBM18 菌株的真菌生理学进行比较分析，研究了其抗真菌作用。此外，还评估了其对真菌生长速度和无性孢子形成的影响。此外，通过 HPLC-MS/MS 进行了真菌产毒分析，以了解细菌对真菌产生的黄曲霉毒素 B1、B2、G1 和 G2 以及伏马菌素 B1 和 B2 的抗产毒活性。最后，在最有效的细菌接种浓度下，采用反转录定量实时 PCR（RT-qPCR）分析，评估与产毒的黄曲霉 nomius 菌株的黄曲霉毒素生物合成相关的基因 aflR、aflQ 和 aflD 的下调情况。认为这些毒素污染的影响是生物和非生物因素的综合作用的结果，如生物之间的相互作用和环境的理化特性。讨论了几种可能的作用机制以及戊糖片球菌滥用作为生物农药可能带来的有害影响，强调了在新的应用、浓度和暴露场景下评估乳酸菌安全性的重要性。
