Publications by authors named "Agustin Lopez-Munguia"

Levan is an enzymatically synthesized fructose polymer with widely reported structural heterogeneity depending on the producing levansucrase, the reaction conditions employed for its synthesis and the characterization techniques. We studied here the specific properties of levan produced by recombinant levansucrase from B. subtilis 168 (Bs-SacB), often characterized as a bimodal distribution, that is, a mixture of low and high molecular weight levan.

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Pozol is a traditional prehispanic Mexican beverage made from fermented nixtamal dough; it is still part of everyday life in many communities due to its nutritional properties. It is the product of spontaneous fermentation and has a complex microbiota composed primarily of lactic acid bacteria (LAB). Although this is a beverage that has been used for centuries, the microbial processes that participate in this fermented beverage are not well understood.

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strains are common contributors in fermented foods producing a wide variety of polysaccharides from sucrose through glycosyltransferases (GTFs). These polymers have been proposed as protective barriers against acidity, dehydration, heat, and oxidative stress. Despite its presence in many traditional fermented products and their association with food functional properties, regulation of GTFs expression in is still poorly understood.

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the Pacific whiteleg shrimp, is one of the most marketable species in aquaculture worldwide. However, it is susceptible to different infections causing considerable losses in production each year. Consequently, using prebiotics that promotes the proliferation of beneficial bacteria and strengthen the immune system is a current strategy for disease control.

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Background: Although Levan-type fructooligosaccharides (L-FOS) have been shown to exhibit prebiotic properties, no efficient methods for their large-scale production have been proposed. One alternative relies on the simultaneous levan synthesis from sucrose, followed by endolevanase hydrolysis. For this purpose, several options have been described, particularly through the synthesis of the corresponding enzymes in recombinant Escherichia coli.

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Prebiotics and probiotics have shown a number of beneficial impacts preventing diseases in cultured shrimps. Complex soluble carbohydrates are considered ideal for fostering microbiota biodiversity by fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPS). Here we evaluated the growth performance and microbiota composition of the white shrimp Litopenaeus vannamei after dietary intervention using agavin as a FODMAP prebiotic under farming conditions.

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Carbohydrate metabolism via cyclodextrins (CM-CD) is an uncommon starch-converting pathway that thoroughly depends on extracellular cyclomaltodextrin glucanotransferases (CGTases) to transform the surrounding starch substrate to α-(1,4)-linked oligosaccharides and cyclodextrins (CDs). The CM-CD pathway has emerged as a convenient microbial adaptation to thrive under extreme temperatures, as CDs are functional amphipathic toroids with higher heat-resistant values than linear dextrins. Nevertheless, although the CM-CD pathway has been described in a few mesophilic bacteria and archaea, it remains obscure in extremely thermophilic prokaryotes (T ≥ 70 °C).

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The genus is composed of a group of Gram-positive facultative anaerobe bacteria with fermentative metabolism. Strains of this genus have been isolated from various ecological niches, including a wide variety of fermented cereal foods. The present study aimed to determine the relative abundance and fermentation capabilities of species isolated from , a traditional product made of lime-cooked (nixtamalized) fermented maize.

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is the sap collected from , while is the result of the natural fermentation of . Despite its ancestral origin and numerous publications on production, little is known about the evolution and concentration of sugars and fructo-oligosaccharides in , either during its daily accumulation or through the agave production lifetime. In this study, we examined composition in three agave plants during their productive lifetime (4 to 9 months).

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Mutation S164A largely affects the transfructosylation properties of Bacillus subtilis levansucrase (SacB). The variant uses acceptors such as glucose and short levans with an average molecular weight of 7.6 kDa more efficiently than SacB, leading to the enhanced synthesis of medium and high molecular weight polymer and a blasto-oligosaccharide series with a polymerization degree of 2-10.

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Deep Eutectic Solvents (DES) were investigated as new reaction media for the synthesis of alkyl glycosides catalyzed by the thermostable α-amylase from Amy A. The enzyme was almost completely deactivated when assayed in a series of pure DES, but as cosolvents, DES containing alcohols, sugars, and amides as hydrogen-bond donors (HBD) performed best. A choline chloride:urea based DES was further characterized for the alcoholysis reaction using methanol as a nucleophile.

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The specificity of fructooligosaccharides as prebiotics depends on their size and structure, which in turn depend on their origin or the synthesis procedure. In this work we describe the application of an inulosucrase (IslA) from CW28 to produce high molecular weight inulin from sucrose alongside a commercial endoinulinase (Novozym 960) produced by for a simultaneous or sequential reaction to synthesize fructooligosaccharides (FOS). The simultaneous reaction resulted in a higher substrate conversion and a wide diversity of FOS when compared to the sequential reaction.

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The physicochemical properties and biological activity of levan, a generic term given to oligo- and polysaccharides consisting of fructose units linked predominantly by β(2-6) bonds, are attributable to both its size and structural complexity. Branching in β(2-1) contributes to diversify levan structures and properties. There is a broad spectrum of applications for levan and accordingly it has been the subject of several comprehensive reviews.

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The thermostable β-fructosidase (BfrA) from the bacterium Thermotoga maritima converts sucrose into glucose, fructose, and low levels of short-chain fructooligosaccharides (FOS) at high substrate concentration (1.75 M) and elevated temperatures (60-70 °C). In this research, FOS produced by BfrA were characterized by HPAE-PAD analysis as a mixture of 1-kestotriose, 6-kestotriose (neokestose), and to a major extent 6-kestotriose.

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Prebiotic fructooligosaccharides (FOS) are currently obtained by enzymatic reaction with fructosyltransferases (FTFs) using sucrose as both donor and acceptor. In these reactions glucose results as the most abundant by-product, arising from each fructosyl transfer event and, together with fructose, because of the inherent hydrolytic activity of the FTFs. As FOS are mainly used as prebiotic in nutraceutical foods, the reduction or total elimination of monosaccharides is required.

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Under specific reaction conditions, levansucrase from Bacillus subtilis (SacB) catalyzes the synthesis of a low molecular weight levan through the non-processive elongation of a great number of intermediates. To deepen understanding of the polymer elongation mechanism, we conducted a meticulous examination of the fructooligosaccharide profile evolution during the levan synthesis. As a result, the formation of primary and secondary intermediates series in different reaction stages was observed.

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CW28 was isolated from pozol, a Mayan fermented corn beverage. This strain produces a cell-associated inulosucrase, the first described in bacteria. Its draft genome sequence, announced here, has an estimated size of 1.

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We describe here the enzymatic production of levan type-fructooligosaccharides (L-FOS) with a DP from 2 to 10, through simultaneous synthesis and hydrolysis reactions. This was accomplished by LevBSacB, a new enzyme resulting from the fusion of SacB, a levansucrase from Bacillus subtilis and LevB, an endolevanase from B. licheniformis.

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Blastose, a natural disaccharide found in honey, is usually found as a byproduct of fructo-oligosaccharide synthesis from sucrose with fructosyltransferases. In this study, we describe a novel two-step biosynthetic route to obtain blastose, designed from a detailed observation of B. subtilis levansucrase (SacB) acceptor structural requirements for fructosylation.

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Pulque is a traditional Mexican alcoholic beverage produced from the fermentation of the fresh sap known as aguamiel (mead) extracted from several species of Agave (maguey) plants that grow in the Central Mexico plateau. Currently, pulque is produced, sold and consumed in popular districts of Mexico City and rural areas. The fermented product is a milky white, viscous, and slightly acidic liquid beverage with an alcohol content between 4 and 7° GL and history of consumption that dates back to pre-Hispanic times.

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Two levan distributions are produced typically by Bacillus subtilis levansucrase (SacB): a high-molecular weight (HMW) levan with an average molecular weight of 2300 kDa, and a low-molecular weight (LMW) levan with 7.2 kDa. Previous results have demonstrated how reaction conditions modulate levan molecular weight distribution.

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Levansucrase catalyzes the synthesis of fructose polymers through the transfer of fructosyl units from sucrose to a growing fructan chain. Levanase activity of Bacillus subtilis levansucrase has been described since the very first publications dealing with the mechanism of levan synthesis. However, there is a lack of qualitative and quantitative evidence regarding the importance of the intrinsic levan hydrolysis of B.

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Levan is a fructan polymer that offers a variety of applications in the chemical, health, cosmetic and food industries. Most of the levan applications depend on levan molecular weight, which in turn depends on the source of the synthesizing enzyme and/or on reaction conditions. Here we demonstrate that in the particular case of levansucrase from Bacillus subtilis 168, enzyme concentration is also a factor defining the molecular weight levan distribution.

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