Institute of Microbiology, Bulgarian Academy of Sciences, 26, Acad. G. Bontchev Str., 1113 Sofia, Bulgaria.
Z Naturforsch C J Biosci. 2010 Mar-Apr;65(3-4):218-24. doi: 10.1515/znc-2010-3-409.
The lactic acid fermentation is a worldwide method for cereal processing. Great diversity of fermented foods and drinks is produced with the participation of amylolytic lactic acid bacteria (ALAB). In the present study the ALAB content of the Bulgarian cereal beverage "boza" was investigated. Two strains, Bom 816 and N3, were found to possess significant amylolytic activity. The strains' identification was based on genetic criteria, namely amplified ribosomal DNA restriction analysis (ARDRA) and sequencing of the 16S rDNA. The strain Bom 816 belongs to the species Lactobacillus plantarum and N3 to Lactobacillus pentosus, being the first amylolytic representative of this species. Optimization of the media composition with starch as a sole carbon source was done. The starch hydrolysis was most efficient in medium containing 4 g/l yeast and 8 g/l meat extracts. Thus, L. plantarum Bom 816 consumed 14 g/l starch, while L. pentosus N3 consumed 17 g/l. The highest values of lactic acid reached were 9.5 g/l produced by Bom 816 and 5.5 g/l produced by N3. In the presence of yeast extract L. pentosus N3 formed 0.8-1 g/l succinic acid. Both strains produced mainly cell-bound enzymes with amylase activity, at a pH optimum of 5.5, ranging from 3-4 to 21 U/ml for L. pentosus N3 and from 0.5 to 11.5 U/ml for L. plantarum Bom 816, in dependence of the assay conditions.
乳酸发酵是一种全球性的谷物加工方法。在淀粉分解性乳酸菌（ALAB）的参与下，生产出了种类繁多的发酵食品和饮料。本研究调查了保加利亚谷物饮料“博扎”中的 ALAB 含量。发现两种菌株 Bom 816 和 N3 具有显著的淀粉分解活性。基于遗传标准，即扩增核糖体 DNA 限制分析（ARDRA）和 16S rDNA 测序，对菌株进行了鉴定。菌株 Bom 816 属于植物乳杆菌，N3 属于戊糖乳杆菌，是该物种的第一个淀粉分解代表。对以淀粉为唯一碳源的培养基组成进行了优化。在含有 4 g/l 酵母和 8 g/l 肉浸膏的培养基中，淀粉水解效率最高。因此，L. plantarum Bom 816 消耗了 14 g/l 淀粉，而 L. pentosus N3 消耗了 17 g/l。达到的最高乳酸值分别为 9.5 g/l（由 Bom 816 产生）和 5.5 g/l（由 N3 产生）。在酵母提取物存在的情况下，L. pentosus N3 形成 0.8-1 g/l 的琥珀酸。两种菌株均主要产生具有淀粉酶活性的细胞结合酶，最适 pH 为 5.5，L. pentosus N3 的酶活范围为 3-4 至 21 U/ml，L. plantarum Bom 816 的酶活范围为 0.5 至 11.5 U/ml，具体取决于测定条件。
