Hydrolase Activities of Sourdough Microorganisms

Abstract

Sourdough is renowned for improving bakery products’ nutritional and quality characteristics through the enzymes produced by its microbiota. Among the enzymatic framework present in sourdough fermentation, amylase, cellulase, and peptidase are responsible for many of the properties valued in sourdough products. Furthermore, there is an increasing concern regarding the allergenic potential of gluten, which motivates the investigation of enzymatic gluten hydrolysis. This study aimed to select probiotics, isolate and identify microorganisms from sourdough, and assess their amylase, cellulase, and peptidase profiles. Additionally, a rapid screening method was developed for gluten and wheat flour hydrolysis, and gluten zymography and enzymography were performed. As a result, 18 microorganisms were isolated from sourdough and identified. The probiotic Bacillus licheniformis LMG-S 28935, and three microorganisms isolated from sourdough, the Limosilactobacillus fermentum, Pediococcus pentosaceus, and Saccharomyces cerevisiae, completed the profile of analyzed hydrolases and presented the capacity to hydrolyze gluten. These findings contribute to a better understanding of sourdough microorganisms’ hydrolase activities in the bakery science and technology field. In addition, an efficient, fast, and economical method for screening extracellular glutenase, produced by microorganisms, was applied. To our knowledge, it was the first time that amylase, cellulase, and peptidase activities were assessed from sourdough microorganisms.

Microbial Preservation and Contamination Control in the Baking Industry

“…However, other genera are also observed, such as Kazachstania, Kluyveromyces, Pichia, and Torulaspora [24]. The adaptability of S. cerevisiae to the fermentation environment in baking and years of use have brought a performance challenge that surpasses others [8]. Other genera of bacteria less studied in sourdough are Acetobacter, Gluconobacter, Komagataeibacter, Bacillus, Pantoea, Kosakonia, Pseudomonas, and Paraburkholderia [8,[27][28][29][30][31].…”

“…The starter used in sourdough and yeast cultures drives the quality of the bread. Besides yeast and LAB, adding other microorganisms, probiotics, postbiotics, or microbial enzymes during the bread preparation makes it possible to introduce unique characteristics such as decreased gluten content or increased mineral bio availability [7][8][9].…”

Microorganisms, Drying, and Preservation Processes in the Baking Industry

“…However, other genera are also observed, such as Kazachstania, Kluyveromyces, Pichia, and Torulaspora [33]. The adaptability of S. cerevisiae to the fermentation environment in baking and years of use have brought a performance challenge to surpass [6]. However, other yeasts have exciting properties that are currently being explored.…”

“…Among the metabolites produced by natural fermentation, organic acids, aldehydes, esters, alcohols, and ketones are prominent [47], as are exopolysaccharides [48], enzymes [6,7], vitamins B12, folate, and riboflavin [49], free amino acids [50,51], and an increase in the bioavailability of minerals [52][53][54][55][56]. Furthermore, bacteriocins, proteins, or peptides that do not pose problems for consumption do not induce resistance [57] and serve as natural preservatives.…”

“…The starter culture drives the quality of the bread. Besides yeast and LAB, adding other microorganisms, postbiotics, or microbial enzymes to the bread preparation could introduce special characteristics such as lower gluten content or more mineral bioavailability through their enzymes [5][6][7]. Freeze-drying, spray drying, fluidized bed drying, microencapsulation, and other technologies can preserve the microorganisms [8].…”