The influence of lactulose on growth and survival of probiotic bacteria Lactobacillus acidophilus La-5 and Bifidobacterium animalis subsp. lactis BB-12 in reconstituted sweet whey.

The influence of lactulose on growth and survival of probiotic bacteria Lactobacillus acidophilus La-5 and Bifidobacterium animalis subsp.lactis BB-12 in reconstituted sweet whey SummaryThis research was examined the influence of lactulose, a well-defined prebiotic, on the growth and activity of probiotic bacteria Lactobacillus acidophilus La-5 and Bifidobacterium animalis subsp.lactis BB-12 in reconstituted sweet whey as well as their survival in fermented whey during 28 days of cool storage.Reconstituted sweet whey was supplemented with 5 and 10 g/kg lactulose.Fermentation of whey with Bifidobacterium animalis subsp.lactis BB-12 was about 1.8 h shorter (approximately 11 h) in comparison to fermentation with Lactobacillus acidophilus La-5 (approximately 13 h).Lactulose addition in reconstituted sweet whey prolonged the time of fermentation in both bacteria species, but it did not influence on the viable cells count at the end of fermentation.Lactobacillus acidophilus La-5 better grew (∆log CFU/mL = 1.25) during fermentation in comparison with Bifidobacterium animalis subsp.lactis BB-12 (∆log CFU/mL = 0.27), regardless to the added amount of lactulose.During storage of fermented whey viable cells count of species Bifidobacterium animalis subsp.lactis BB-12 was more stable than count of Lactobacillus acidophilus La-5.The obtained results show that lactulose, as a well-defined prebiotic did not have a significant effect on fermentation and survival of Lactobacillus acidophilus La-5 and Bifidobacterium animalis subsp.lactis BB-12 in whey, regardless to the added amount.