Visintin Simonetta, Alessandria Valentina, Valente Antonio, Dolci Paola, Cocolin Luca
University of Torino, Department of Agriculture, Forest and Food Sciences, Largo Paolo Braccini 2, 10095 Grugliasco, Torino, Italy.
SOREMARTEC ITALIA S.r.l., Piazza Ferrero 1 - 12051 Alba, Cuneo, Italy.
Int J Food Microbiol. 2016 Jan 4;216:69-78. doi: 10.1016/j.ijfoodmicro.2015.09.004. Epub 2015 Sep 11.
Yeast, lactic acid bacteria (LAB) and acetic acid bacteria (AAB) populations, isolated from cocoa bean heap and box fermentations in West Africa, have been investigated. The fermentation dynamicswere determined by viable counts, and 106 yeasts, 105 LAB and 82 AAB isolateswere identified by means of rep-PCR grouping and sequencing of the rRNA genes. During the box fermentations, the most abundant species were Saccharomyces cerevisiae, Candida ethanolica, Lactobacillus fermentum, Lactobacillus plantarum, Acetobacter pasteurianus and Acetobacter syzygii, while S. cerevisiae, Schizosaccharomyces pombe, Hanseniaspora guilliermondii, Pichia manshurica, C. ethanolica, Hanseniaspora uvarum, Lb. fermentum, Lb. plantarum, A. pasteurianus and Acetobacter lovaniensis were identified in the heap fermentations. Furthermore, the most abundant species were molecularly characterized by analyzing the rep-PCR profiles. Strains grouped according to the type of fermentations and their progression during the transformation process were also highlighted. The yeast, LAB and AAB isolates were physiologically characterized to determine their ability to grow at different temperatures, as well as at different pH, and ethanol concentrations, tolerance to osmotic stress, and lactic acid and acetic acid inhibition. Temperatures of 45 °C, a pH of 2.5 to 3.5, 12% (v/v) ethanol and high concentrations of lactic and acetic acid have a significant influence on the growth of yeasts, LAB and AAB. Finally, the yeastswere screened for enzymatic activity, and the S. cerevisiae, H. guilliermondii, H. uvarumand C. ethanolica species were shown to possess several enzymes that may impact the quality of the final product.
对从西非可可豆堆发酵和箱式发酵中分离出的酵母、乳酸菌（LAB）和醋酸菌（AAB）菌群进行了研究。通过活菌计数确定发酵动态，并通过rep-PCR分组和rRNA基因测序对106株酵母、105株LAB和82株AAB分离株进行了鉴定。在箱式发酵过程中，最丰富的物种是酿酒酵母、乙醇假丝酵母、发酵乳杆菌、植物乳杆菌、巴氏醋酸杆菌和合子醋酸杆菌，而在堆式发酵中鉴定出的有酿酒酵母、粟酒裂殖酵母、季也蒙毕赤酵母、曼氏毕赤酵母、乙醇假丝酵母、葡萄汁有孢汉逊酵母、发酵乳杆菌、植物乳杆菌、巴氏醋酸杆菌和洛凡尼醋酸杆菌。此外，通过分析rep-PCR图谱对最丰富的物种进行了分子表征。还强调了根据发酵类型及其在转化过程中的进程进行分组的菌株。对酵母、LAB和AAB分离株进行了生理表征，以确定它们在不同温度、不同pH值、乙醇浓度下的生长能力、对渗透胁迫的耐受性以及对乳酸和醋酸抑制的耐受性。45℃的温度、2.5至3.5的pH值、12%（v/v）的乙醇以及高浓度的乳酸和醋酸对酵母、LAB和AAB的生长有显著影响。最后，对酵母进行了酶活性筛选，结果表明酿酒酵母、季也蒙毕赤酵母、葡萄汁有孢汉逊酵母和乙醇假丝酵母物种拥有几种可能影响最终产品质量的酶。
