RESUMO
Lactobacillus sp. synthesize exopolysaccharides (EPS), including both homo- and heteropolysaccharides, which play an important role in the production of fermented foods, and especially in the dairy industry, improving the gustatory and rheological properties of the finished products. These polymers are generated by starter cultures in situ in fermented foods, and so they are treated as natural thickening agents. As some Lactobacillus strains are generally recognized as safe and have been shown to exhibit probiotic activity, EPS from those bacteria can be used as functional food ingredients, conferring both health and economic benefits to the consumers. However, their industrial applications are hindered by the low yield of EPS from Lactobacillus and high costs of their purification. This review focuses on the latest reports concerning the biosynthesis and properties of Lactobacillus EPS.
Assuntos
Lactobacillus/metabolismo , Polissacarídeos Bacterianos/biossíntese , Configuração de Carboidratos , Tecnologia de Alimentos , Humanos , Polissacarídeos Bacterianos/química , ProbióticosRESUMO
Lactobacillus strains can synthesize capsular polysaccharides (CPS), which are important substances in the dairy industry-they exhibit many important technological as well as health-promoting properties. Technological advancements have made it possible to detect bacterial capsules using costly and labor-intensive methods, such as serological reactions, molecular genetic techniques, and electron microscopy. Light microscopy, which is the method of interest in this paper, is one of the most widely accessible and cheapest techniques. CPS may be observed under a light microscope after staining bacterial cells and the background with a basic die and an acidic die, respectively (negative-positive staining), with the capsules remaining transparent. The literature offers many polysaccharide staining methods, but due to the considerable structural diversity of CPS and possible dye-capsule interactions, a suitable staining technique should be carefully selected for each strain. The current study showed that not all methods adequately reveal Lactobacillus CPS, with the most effective ones being those proposed by Hiss and Maneval.
Assuntos
Cápsulas Bacterianas/química , Lactobacillus/química , Polissacarídeos Bacterianos/biossíntese , Laticínios/microbiologia , Microbiologia de AlimentosRESUMO
The aim of this study was to determine the effectiveness of microbial preparation and Yucca schidigera in the removal of odorous volatile compounds from poultry manure as well as to evaluate antimicrobial properties of these amendments. It was demonstrated that the combined treatment of poultry manure (PM) with the microbial preparation and Y. schidigera extract can reduce the concentration of odorants by 58%-73%, depending on the tested compound. When Y. schidigera extract and the microbial preparation were applied at a time interval of 48 h, the deodorization efficiency was improved by 6-24%. Furthermore, Y. schidigera extract has antimicrobial properties, which affect poultry manure hygienization. It was found that when the microbial preparation was enriched with Lactobacillus plantarum, it became insensitive to the antimicrobial properties of Y. schidigera.