Acceptor specificity of amylomaltase from Corynebacterium glutamicum and transglucosylation reaction to synthesize palatinose glucosides

Maltotriosyl-erythritol, a transglycosylation product of erythritol by Thermus sp. amylomaltase and its application to prebiotic

In this study, maltotriosyl-erythritol (EG3) was synthesized as a novel prebiotic candidate via transglycosylation using recombinant amylomaltase (AMase) from Thermus sp. Tapioca starch served as the glucosyl donor, and erythritol as the acceptor. High-performance liquid chromatography (HPLC) revealed an EG3 yield of 14.0 % with a concentration of 2.8 mg/mL. Mass spectrometry confirmed the molecular weight of EG3 as 608 Da, and its strucopture was verified by 1H and 13C NMR analysis. EG3 exhibited greater resistance to acid, heat, and digestive enzymes compared to erythritol glucosides (EG1-2) and significantly promoted the growth of Lactobacillus casei BCC36987. Fermentation of EG3 resulted in the highest levels of lactic acid and total short-chain fatty acids, which may contribute to reduced pH levels. These findings suggest that erythritol-receptor products formed via AMase-catalyzed reactions, particularly EG3, are promising prebiotic ingredients, with the prebiotic activity of erythritol derivatives being influenced by the length of the carbohydrate chain.

Ovine and Caprine Strains of Corynebacterium pseudotuberculosis on Czech Farms-A Comparative Study

Caseous lymphadenitis (CLA) is a worldwide disease of small ruminants caused by Corynebacterium pseudotuberculosis, a facultative intracellular pathogen that is able to survive and multiply in certain white blood cells of the host. In this study, 33 strains of C. pseudotuberculosis were isolated from sheep and goats suffering from CLA on nine farms in the Czech Republic. All these strains were tested for their antibiotic susceptibility, ability to form a biofilm and resistance to the effects of commonly used disinfectant agents. To better understand the virulence of C. pseudotuberculosis, the genomes of strains were sequenced and comparative genomic analysis was performed with another 123 genomes of the same species, including ovis and equi biovars, downloaded from the NCBI. The genetic determinants for the virulence factors responsible for adherence and virulence factors specialized for iron uptake and exotoxin phospholipase D were revealed in every analyzed genome. Carbohydrate-Active Enzymes were compared, revealing the presence of genetic determinants encoding exo-α-sialidase (GH33) and the CP40 protein in most of the analyzed genomes. Thirty-three Czech strains of C. pseudotuberculosis were identified as the biovar ovis on the basis of comparative genome analysis. All the compared genomes of the biovar ovis strains were highly similar regardless of their country of origin or host, reflecting their clonal behavior.