Aerobic adaptation and metabolic dynamics of DSM 20271: insights from comparative transcriptomics and surfaceome analysis.

Unlabelled: () DSM 20271 is a bacterium known for its ability to thrive in diverse environments and to produce vitamin B12. Despite its anaerobic preference, recent studies have elucidated its ability to prosper in the presence of oxygen, prompting a deeper exploration of its physiology under aerobic conditions. Here, we investigated the response of DSM 20271 to aerobic growth by employing comparative transcriptomic and surfaceome analyses alongside metabolite profiling.

Bioaccessibility of vitamin B12 synthesized by and from products made with fermented wheat bran extract.

The bioaccessibility of vitamin B12 (B12) in plant-based products fortified using wheat bran extract fermented with B12-producing food-grade was studied by applying a standard static model. At first, a culture of , fresh or heat-treated, was subjected to assays. Then, food ingredients or products were evaluated for their bioaccessibility: spray-dried wheat bran extract powder, pasta made with an extruder using fermented bran extract and breads made with spray-dried powder or with added cyanocobalamin.

Co-fermentation of and in Wheat Bran for Production of Vitamin B12.

The present study investigated the effect of co-fermentation on vitamin B12 content and microbiological composition of wheat bran. DSM 20271 was used as the producer of vitamin while ATCC 14869 was selected to ensure the microbial safety of the bran dough. Fermentation trials were conducted in bioreactors to monitor and adjust the pH of the ferments.

production of active vitamin B12 in cereal matrices using .

The production of active vitamin B12 was investigated in aqueous cereal-based matrices with three strains of food-grade . Matrices prepared from malted barley flour (33% w/v; BM), barley flour (6%; BF), and wheat aleurone (15%; AM) were fermented. The effect of cobalt and the lower ligand 5,6-dimethylbenzimidazole (DMBI) or its natural precursors (riboflavin and nicotinamide) on active B12 production was evaluated.

Microbial Metabolic Networks at the Mucus Layer Lead to Diet-Independent Butyrate and Vitamin B Production by Intestinal Symbionts.

has evolved to specialize in the degradation and utilization of host mucus, which it may use as the sole source of carbon and nitrogen. Mucus degradation and fermentation by are known to result in the liberation of oligosaccharides and subsequent production of acetate, which becomes directly available to microorganisms in the vicinity of the intestinal mucosa. Coculturing experiments of with non-mucus-degrading butyrate-producing bacteria , , and resulted in syntrophic growth and production of butyrate.

Food-Like Growth Conditions Support Production of Active Vitamin B12 by 2067 without DMBI, the Lower Ligand Base, or Cobalt Supplementation.

is a traditional dairy bacterium and a producer of short chain fatty acids (propionic and acetic acids) as well as vitamin B12. In food applications, it is a promising organism for fortification with B12 vitamin since it is generally recognized as safe (GRAS) and it is able to synthesize biologically active form of the vitamin. In the present study, vitamin B12 and pseudovitamin biosynthesis by was monitored by UHPLC as a function of growth in food-like conditions using a medium mimicking cheese environment, without cobalt or 5,6-dimethylbenzimidazole (DMBI) supplementation.

Comparative genomics and physiology of the butyrate-producing bacterium Intestinimonas butyriciproducens.

Intestinimonas is a newly described bacterial genus with representative strains present in the intestinal tract of human and other animals. Despite unique metabolic features including the production of butyrate from both sugars and amino acids, there is to date no data on their diversity, ecology, and physiology. Using a comprehensive phylogenetic approach, Intestinimomas was found to include at least three species that colonize primarily the human and mouse intestine.

Stability of added and in situ-produced vitamin B12 in breadmaking.

Vitamin B12 exists naturally in foods of animal origin and is synthesised only by certain bacteria. New food sources are needed to ensure vitamin B12 intake in risk groups. This study aimed to investigate the stability of added cyanocobalamin (CNCbl, chemically modified form) and hydroxocobalamin (OHCbl, natural form) and in situ-synthesised vitamin B12 in breadmaking.

BluB/CobT2 fusion enzyme activity reveals mechanisms responsible for production of active form of vitamin B₁₂ by Propionibacterium freudenreichii.

Background: Propionibacterium freudenreichii is a food grade bacterium that has gained attention as a producer of appreciable amounts of cobalamin, a cobamide with activity of vitamin B12. Production of active form of vitamin is a prerequisite for attempts to naturally fortify foods with B12 by microbial fermentation. Active vitamin B12 is distinguished from the pseudovitamin by the presence of 5,6-dimethylbenzimidazole (DMBI) as the lower ligand.

Ultra-high performance liquid chromatographic and mass spectrometric analysis of active vitamin B12 in cells of Propionibacterium and fermented cereal matrices.

A sensitive and selective method is needed to analyse in situ produced vitamin B12 in plant-based materials, potential new dietary sources of vitamin B12. A UHPLC/UV method was developed and validated for the determination of human active vitamin B12 in cell extracts of Propionibacterium freudenreichii subsp. shermanii and after immunoaffinity purification in extracts of cereal matrices fermented by P.

Trends of Antibiotic Resistance in Mesophilic and Psychrotrophic Bacterial Populations during Cold Storage of Raw Milk.

Psychrotrophic bacteria in raw milk are most well known for their spoilage potential and cause significant economic losses in the dairy industry. Despite their ability to produce several exoenzyme types at low temperatures, psychrotrophs that dominate the microflora at the time of spoilage are generally considered benign bacteria. It was recently reported that raw milk-spoiling Gram-negative-psychrotrophs frequently carried antibiotic resistance (AR) features.