Dipartimento di Scienze per gli Alimenti, la Nutrizione e l'Ambiente, Università degli Studi di Milano, Milan, Italy.
Rizek Cocoa S.A.S., San Francisco de Macorìs, Dominican Republic.
J Appl Microbiol. 2022 Sep;133(3):1769-1780. doi: 10.1111/jam.15687. Epub 2022 Jul 2.
To investigate the characteristics of two minority autochthonous LAB species, with particular regard to those properties that could be exploited in an improved cocoa fermentation process from a quality and safety point of view.
Bacterial, yeast and mould strains characteristic of spontaneously fermented Dominican cocoa beans were isolated and identified by 16S or 26S rRNA gene sequencing. The potential of two autochthonous strains of LAB belonging to the species Lactiplantibacillus fabifermentans and Furfurilactibacillus rossiae were investigated. The two selected LAB strains were able to utilize glucose and fructose, produced mainly D-L lactic acid and had a good ability to resist to cocoa-related stress conditions such as low pH, high temperature and high osmotic pressure, as well as to grow in sterile cocoa pulp. The strains did not inhibit the growth of yeasts and acetic acid bacteria, that are essential to the cocoa fermentation process, and possessed a complex pool of peptidases especially active on hydrophobic amino acids. The strains also showed antifungal activity against mould species that can be found at the final stages of cocoa fermentation, as Aspergillus tamarii, A. nidulans, Lichtheimia ornata and Rhizomucor pusillus.
The tested strains are good candidates for the design of starter cultures for a controlled cocoa fermentation process.
This research showcases the potential of two alternative LAB species to the dominating Lactiplantibacillus plantarum and Limosilactibacillus fermentum as cocoa fermentation starters, with an interesting activity in improving the safety and quality of the process.
研究两种本土乳酸菌（LAB）少数民族物种的特性，尤其关注从质量和安全角度出发，在改良可可发酵过程中可利用的特性。
通过 16S 或 26S rRNA 基因测序对具有代表性的多米尼加可可豆自然发酵的细菌、酵母和霉菌菌株进行分离和鉴定。研究了属于发酵乳杆菌（Lactiplantibacillus fabifermentans）和罗斯氏乳杆菌（Furfurilactibacillus rossiae）的两种本土 LAB 菌株的潜力。这两种选定的 LAB 菌株能够利用葡萄糖和果糖，主要产生 D-L 乳酸，并且具有很好的抵抗与可可相关的应激条件的能力，如低 pH 值、高温和高渗透压，以及在无菌可可果肉中生长的能力。这些菌株不会抑制对可可发酵过程至关重要的酵母和醋酸菌的生长，并且具有复杂的肽酶库，对疏水性氨基酸特别活跃。这些菌株还对在可可发酵后期发现的霉菌物种（如黑曲霉、米根霉、华丽枝霉和少根根霉）表现出抗真菌活性。
测试的菌株是设计可可发酵过程控制发酵剂的良好候选菌株。
这项研究展示了两种替代的 LAB 物种（即优势的植物乳杆菌和发酵乳杆菌）作为可可发酵起始菌株的潜力，它们在改善过程的安全性和质量方面具有有趣的活性。
