Catabolism of Glucose and Lactose in Bifidobacterium animalis subsp. lactis, Studied by ¹³ C Nuclear Magnetic Resonance

Abstract

Bifidobacteria are widely used as probiotics in several commercial products; however, to date there is little knowledge about their carbohydrate metabolic pathways. In this work, we studied the metabolism of glucose and lactose in the widely used probiotic strain Bifidobacterium animalis subsp.

Impact of coculturingBifidobacterium animalissubsp.lactisHN019 with yeasts on microbial viability and metabolite formation

“…; Gonzalez‐Rodriguez et al . ). The incubation temperature used in this study affected the viability of several yeasts during fermentation.…”

“…The nonlactose fermenting yeasts could have utilized amino acids, peptides and organic acids as energy sources to support their growth in the medium (Gadaga et al 2001;Neviani et al 2001;Lee et al 2011). When cocultured with B. lactis, the yeasts could assimilate the glucose and galactose (Table S1) released from lactose hydrolysis by the bifidobacterial extracellular b-galactosidase (Gadaga et al 2001;Gonzalez-Rodriguez et al 2013). The incubation temperature used in this study affected the viability of several yeasts during fermentation.…”

“…Alcohols and esters were the two groups of volatile metabolites that were markedly higher in cocultures. Ethanol is a generated by bifidobacteria as a bifid shunt product from the reduction of acetyl-CoA by aldehydealcohol dehydrogenase (Gonzalez-Rodriguez et al 2013). Kluyveromyces lactis and S. cerevisiae could have fermented lactose and/or glucose/galactose in the medium, thereby contributing to the higher ethanol content in their respective cocultures (Neviani et al 2001;Santos et al 2014).…”

“…Furthermore, carbohydrate metabolism by bifidobacteria via the bifid shunt produces a higher proportion of acetic acid than lactic acid (Gonzalez‐Rodriguez et al . ). This imparts a vinegary off‐odour to the fermented milk and hinders the application of bifidobacteria as a primary starter culture (Gomes and Malcata ).…”

“…Nevertheless, the low concentrations of free essential amino acids in milk and the presence of dissolved oxygen during fermentation makes propagating bifidobacteria a challenging task (Talwalkar and Kailasapathy 2004;Yonezawa et al 2010). Furthermore, carbohydrate metabolism by bifidobacteria via the bifid shunt produces a higher proportion of acetic acid than lactic acid (Gonzalez-Rodriguez et al 2013). This imparts a vinegary off-odour to the fermented milk and hinders the application of bifidobacteria as a primary starter culture (Gomes and Malcata 1999).…”