Mabisi is a fermented milk product, traditionally produced in a calabash by uncontrolled fermentation. Due to high costs and a reduced availability of calabashes, nowadays plastic containers are also used for Mabisi production. However, the effect of this change in production practice on the properties of the product has not been documented. Therefore, we aimed at determining the effect of fermentation vessels and types of back-slopping on acidification and microbial communities during fermentation. A series of fifteen experiments using two types of fermentation vessels (plastic buckets and calabashes) in combination with different types of back-slopping (no back-slopping, passive back-slopping, and active back-slopping) were set up at a field site in rural Zambia. In each of the fifteen fermentations we analysed acidification rate of traditional Mabisi fermentation and bacterial diversity over time. No significant difference was found in terms of microbial diversity during and at the end of fermentation between fermentations performed in buckets or previously used calabashes. Bacterial communities in general decreased in diversity over time, where the drop in pH correlated with a decrease in Shannon Index. In case of active back-slopping, the pH drop started right after inoculation while in the no back-slopping and passive back-slopping fermentations, there was a clear lag phase before acidification started. All experimental series resulted in a microbial community dominated by Lactococcus lactis and a Shannon Index, as a measure for diversity, between 0.6 and 2.0. The use of plastic buckets for Mabisi fermentation can be a valuable alternative to the use of calabashes as this study showed no biological and physico-chemical differences between Mabisi resulting from both fermentation vessels, although the reason for perceived differences should be further investigated. Electronic supplementary material The online version of this article (10.1007/s11274-020-02957-5) contains supplementary material, which is available to authorized users.

中文翻译：

---

赞比亚自发发酵乳制品 Mabisi 传统生产过程中的微生物种群动态：田间试验

Mabisi 是一种发酵乳制品，传统上通过不受控制的发酵在葫芦中生产。由于成本高且葫芦的供应量减少，如今塑料容器也用于马比西的生产。然而，生产实践中的这种变化对产品特性的影响尚未记录在案。因此，我们旨在确定发酵容器和后倾类型对发酵过程中酸化和微生物群落的影响。在现场设置了使用两种发酵容器（塑料桶和葫芦）结合不同类型的后倾（无后倾、被动后倾和主动后倾）进行的一系列十五个实验在赞比亚农村。在 15 次发酵中的每一次中，我们分析了传统马比西发酵的酸化率和细菌多样性随时间的变化。在桶中或以前使用的葫芦中进行的发酵之间在发酵期间和结束时的微生物多样性方面没有发现显着差异。随着时间的推移，细菌群落的多样性普遍下降，其中 pH 值的下降与香农指数的下降相关。在主动倒灌的情况下，接种后 pH 值立即下降，而在无倒灌和被动倒灌发酵中，酸化开始前存在明显的滞后阶段。所有实验系列都产生了以乳酸乳球菌为主的微生物群落，香农指数作为多样性的衡量标准，介于 0.6 和 2.0 之间。使用塑料桶进行 Mabisi 发酵可能是使用葫芦的有价值的替代品，因为这项研究表明，两种发酵容器在 Mabisi 之间没有生物和物理化学差异，尽管应进一步调查感知差异的原因。电子补充材料本文的在线版本（10.1007/s11274-020-02957-5）包含补充材料，可供授权用户使用。