Department of Food Science and Technology, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000 Ljubljana, Slovenia.
Toxins (Basel). 2022 Dec 29;15(1):25. doi: 10.3390/toxins15010025.
The aim of the present study was to develop meat-based media with compositions similar to those of dry-fermented meat products and to evaluate their use in studying the growth of and the kinetics of aflatoxin B1 (AFB1) production. In our previous experiments, we found that the strain ŽMJ7 produced a high amount of AFB1. Cooked meat agar (CMA2) was used as a novel complex meat-based medium with four variations: CMA2G (CMA2 supplemented with 1% glucose), CMA2YE (CMA2 supplemented with 0.2% yeast extract), and CMA2GYE (CMA2 supplemented with 1% glucose and 0.2% yeast extract). Media were inoculated with an spore suspension (10 spores/mL) and incubated at 25 °C for up to 15 days. The lag phase lasted less than 1 day, irrespective of the growth medium, with the exception of control medium CMA1 (cooked meat agar) as an already known meat-based medium. The highest mean colony growth rate was observed on CMA2 and CMA2G. Reversed-phase UPLC-MS/MS analysis was performed to determine the AFB1 concentration in combination with solid phase extraction (SPE). The highest AFB1 concentration in meat-based media was detected in CMA2GYE after 15 days of incubation (13,502 ± 2367 ng/mL media). The results showed that for studying AFB1 production in dry-fermented meat products, novel suitable media such as CMA2-based media are required. This finding could represent a potential concern with regard to the production of dry-fermented meat products.
本研究的目的是开发组成类似于干发酵肉类产品的肉类培养基,并评估其在研究和动力学中的应用。在我们之前的实验中,我们发现菌株 MJ7 产生了大量的 AFB1。熟肉琼脂(CMA2)被用作一种新型的复杂肉基培养基,有四种变体:CMA2G(CMA2 中添加 1%葡萄糖)、CMA2YE(CMA2 中添加 0.2%酵母提取物)和 CMA2GYE(CMA2 中添加 1%葡萄糖和 0.2%酵母提取物)。将培养基用悬浮液(10 个孢子/mL)接种,在 25°C 下培养长达 15 天。除了对照培养基 CMA1(熟肉琼脂)作为已知的肉基培养基外,无论生长培养基如何,都没有发现 滞后期持续不到 1 天。最高平均菌落生长速率出现在 CMA2 和 CMA2G 上。采用反相 UPLC-MS/MS 分析结合固相萃取(SPE)法测定 AFB1 浓度。在培养 15 天后,在肉基培养基中检测到 CMA2GYE 中的 AFB1 浓度最高(13502±2367ng/mL 培养基)。结果表明,对于研究干发酵肉类产品中的 AFB1 生产,需要新型合适的培养基,如基于 CMA2 的培养基。这一发现可能与干发酵肉类产品的生产有关。