Amylolytic Lactobacillus Strains from Bulgarian Fermented Beverage Boza

Abstract

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 signifi cant amylolytic activity. The strains' identifi cation was based on genetic criteria, namely amplifi ed 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 fi rst amylolytic representative of this species.Optimization of the media composition with starch as a sole carbon source was done. The starch hydrolysis was most effi cient 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.

Starch‐modifying enzymes of lactic acid bacteria – structures, properties, and applications

“…The major reaction products from soluble starch were maltotriose, maltotetraose, and maltopentaose, but no panose was detected, and maltotriose was the sole product from pullulan [21]. L. plantarum Bom 816 and L. pentosus N3 with cellbond amylase activity were isolated by Petrova et al [14]. The pH and temperature optima of the cell-bond amylases for both strains were pH 5.5 and 458C.…”

“…ALAB are mainly distributed in directly fermented meals, based on manioc, sorghum, rice, millet, maize, cassava, or taro [4][5][6][7][8][9]. Other sources of ALAB are the fermented cereal beverages, such as maize pozol [10], non-alcoholic drink bushera [11], sorghum beer [12], beer malt and beer wort [13], and the probiotic drink boza [14,15]. Thirdly, ALAB could be found in the sour sourdoughs from sorghum, maize (ogi and mawè ), wheat or rye [16][17][18][19][20]; and also in cooked rice-fish products as burong isda and plaa-som [21,22].…”

“…In the majority of the studies, the LAB isolates are characterized and identified by a polyphasic approach based on phenotypic and genotypic methods, such as carbohydrate fermentation patterns using API 50CH [4,10,11,25,26], ribotyping [10], intergenic transcribed spacers-PCR/restriction fragment length polymorphism (ITS-PCR/RFLP) [12], pulsed-field gel electrophoresis (PFGE) [12,26], ARDRA, rep-PCR, RAPD-PCR [7,12,14,20], multiplex-PCR [9], and 16S rRNA gene sequencing [5, 9-12, 15, 20, 26].…”

“…Some of them are used as colorants, spices, drinks, snacks, or light food, while others are a main meal in many areas of the world [27]. Depending on the species and strain composition of ALAB starters, they may be applied for development of probiotic fermented meals and beverages [9,14,94] and for hipo-allergic children foods [8,95]. ALAB producing extracellular amylases are also applied as sourdough starters, especially for the original in taste and aroma bakery products, containing rye and corn flour [41].…”

Antimicrobial Activity of Starch-DegradingLactobacillusStrains Isolated from Boza

“…it has to contain lAB with amylolytic abilities. the Lactobacillus strains investigated here were previously described as amylolytic, as their amylases productions were proved and quantitatively estimated (9). the evaluation of their probiotic potential included the selection of test microbes -common food pathogens (E. coli, K. pneumoniae, V. cholerae); food-spoilage bacteria -B. subtilis; and yeast species, naturally participating in boza.…”