Effective encapsulation of reuterin-producing Limosilactobacillus reuteri in alginate beads prepared with different mucilages/gums.

The mainly aim of this study was to use mucilaginous solutions obtained from tamarind, mutamba, cassia tora, psyllium and konjac powdered to encapsulate reuterin-producing Limosilactobacillus reuteri in alginate beads by extrusion technique. In the particles were determined the bacterial encapsulation efficiency, cell viability during storage and survival under simulated gastric and intestinal conditions. Moreover, the reuterin production, its entrapment into the beads and the influence on viability of encapsulated microorganism were evaluated. Scanning electron microscopy and Fourier Transform Infrared spectroscopy were employed to characterize the produced particles. The beads showed a relatively spherical shape with homogenous distribution of L. reuteri. The use of gums and mucilages combined with alginate improved the encapsulation efficiency (from 93.2 to 97.4%), the viability of encapsulated bacteria during refrigerated storage (especially in prolonged storage of 20, 30 and 60 days) and the survival after exposure to gastric and enteric environments (from 67.7 to 76.6%). The L. reuteri was able to produce reuterin via bioconversion of glycerol in the film-forming solutions, and the entrapment of the metabolite was improved using konjac, mutamba and tamarind mucilaginous solutions in the encapsulation process (45, 44.57 and 41.25%, respectively). Thus, our findings confirm the great potential of these hydrocolloids to different further purposes, enabling its application as support material for delivery of chemical or biological compounds.

Reuterin-producing Limosilactobacillus reuteri: Optimization of in situ reuterin production in alginate-based filmogenic solutions.

Limosilactobacillus reuteri produces reuterin via glycerol anaerobic fermentation. This compound has antimicrobial properties and is used for food preservation purposes. Filmogenic solutions constituted of polysaccharides and glycerol are also employed, however, reuterin synthesis in filmogenic solutions has not yet been reported. Thus, the aim of this study was to optimize the in situ reuterin production by L. reuteri in alginate- and glycerol based-filmogenic solution, evaluating the survival of reuterin-producing bacteria during fermentation. The study consisted of a completely randomized design employing two L. reuteri strains (DSM 20016 and DSM 17938). The filmogenic solutions were obtained using sodium alginate (20 g/L) and two independent variables were studied: glycerol (0-300 mmol/L) and initial biomass of L. reuteri (≅6, 7, and 8 log CFU/mL). The samples were analyzed every 24 h for 72 h of anaerobic fermentation (37 °C). Both L. reuteri strains confirmed the potential for reuterin production and were susceptible to the metabolite produced. The highest reuterin production was achieved using L. reuteri DSM 20016. The initial microbial biomass of 8 log CFU/mL and 100 mmol/L of glycerol increased the reuterin production. However, higher conversion yields from glycerol to reuterin were obtained using 50 mmol/L of substrate.

Encapsulated probiotic cells: Relevant techniques, natural sources as encapsulating materials and food applications - A narrative review.

The administration of probiotic microorganisms in adequate amounts is constantly related to health benefits. To promote beneficial effects, these microorganisms must not be affected by exposure to environmental factors and must be able to adhere and colonize the human gastrointestinal tract. Several encapsulation techniques and encapsulating materials are available to produce probiotic particles, however, it is essential that the process must not be aggressive, reducing or preventing injuries and cell losses, besides, the particle properties obtained must be adequate for the proposed purpose. At the same time, the global market for supplements and probiotic foods has been growing significantly, and cell encapsulation appears as an alternative to incorporate probiotics into different food matrices. This review discusses and updates the main techniques, and the traditional and emerging polysaccharides for encapsulation of probiotic cells, as well as the advantages and possibilities of incorporating produced particles into food matrices. Currently, various scientific studies report the use of different encapsulation techniques, such as extrusion, emulsion, spray drying, spray chilling and fluidized bed to encapsulate probiotics properly. The alginate is still widely used to produce probiotic particles, however, there has been a growing interest in its total or partial substitution with others polysaccharides, such as gums, mucilages, prebiotic compounds and microbial exopolysaccharides, which improve the protection and survival of encapsulated cells and allow their incorporation into dairy and non-dairy food products.

Paenibacillus campinasensis sp. nov., a cyclodextrin-producing bacterium isolated in Brazil.

An alkaliphilic, endospore-forming bacterium isolated from Brazilian soil was taxonomically studied and is proposed as a new Paenibacillus species. This organism (strain 324T) was particularly distinguishable from other Paenibacillus species by its ability to grow optimally at pH 10 and 40 degrees C. The DNA G+C content was 5.0 mol%. The diamine acid of the cell-wall peptidoglycan was meso-diaminopimelic acid. MK-7 was the predominant menaquinone and anteiso-C15:0 was the major fatty acid. Levels of 16S rDNA similarity between strain 324T and other Paenibacillus species were 90.6-95.9%. Phylogenetically, strain 324T formed an evolutionary lineage distinct from other species within the evolutionary radiation encompassing the genus Paenibacillus. Based on phenotyic and chemotaxonomic properties, and phylogenetic inference, it is proposed that strain 324T should be placed in the genus Paenibacillus as a new species is strain 324T should be placed in the genus Paenibacilus as a new species, Paenibacillus campinasensis. This type strain of the new species is strain 325T (= KCTC 0364BP).

Fungal invertase as an aid for fermentation of cane molasses into ethanol.

Comparative studies of the fermentation of cane molasses into ethanol by Saccharomyces cerevisiae in the presence or absence of fungal invertase were performed. When cane molasses was fermented by the yeast at 30 degrees C and pH 5.0, the presence of the enzyme had no effect on ethanol production. At pH 3.5, ethanol production was increased by the addition of invertase. At 40 degrees C, the addition of invertase increased ethanol production by 5.5% at pH 5.0 and by 20.9% at pH 3.5.