Growth Characteristics of Bifidobacteria in Infant Formulas

<p>Four strains of bifidobacteria; B. bifidum (ATCC 15696), B. longum (ATCC 15708), B. breve (ATCC 15700), and B. infantis (ATCC 15697) were rehydrated in MRS broth and inoculated at 2.5% into three types of infant formula: soy-based (SB), milk-based (MB), casein-hydrolyzed (CH), and control, non fat milk (C) followed by incubation at 37°C for 24 h. Mean maximum colony forming unit per milliliter (cfu/ml) for B. bifidum were 6.lxl06 (SB), 1.4xl0⁹ (MB), l.lxl0⁷ (CH), and l.8xl0⁹ (C). Generation time (G) ranged from 96 (MB) to 322 (SB) min. Mean maximum bacterial counts for B. longum were 2.6xl0⁸ (SB), 2.2xl0⁸ (MB), 5.9xl0⁷ (CH), and l.3xl0⁹(C) cfu/ml. Generation times ranged from 121 (C) to 337 (CH) min. For B. breve maximum counts were l.2xl0⁹ (SB), 2.3xl0⁹ (MB), 2.5xl0⁸ (CH), and 2.7xl0⁹ (C) cfu/ml and G ranged from 88 (MB) to 220 (CH) min. The mean maximum counts for B. infantis were 2.4xl0⁸ (SB), 3.7xl0⁸ (MB) 6.8xl0⁷ (CH), and 8.lxl0⁸ (C) cfu/ml with G ranging from 64 (MB) to 120 (CH) min. Counts for SB and MB were similar (P> .05) with all strains except B. bifidum and those for CH were always the lowest (P< .05) for all strains except B. bifidum for which SB had the lowest maximum count. Generation times for B. longum and B. breve indicated similar (P> .05) trends. Results suggest that growth characteristics of bifidobacteria in infant formula were strain specific and that maximum growth occurred in milk-based formula. In another experiment growth promoters, lactulose and fructooligosaccharides (FOS), were inoculated at .5% into SB and CH with 2.5% of above mentioned 4 strains of bifidobacteria and their mixture (mixed-culture), and incubated at 37°C for 24 h. Lactulose did not influence maximum counts and G in SB and CH for all the strains except B. infantis for which counts were lower (P < .05) in CH. Trends of developed acidity and pH in SB and CH with or without lactulose for mixed-culture similar (P > .05) to that for B. breve. Maximum counts and G remained unchanged (P > .05) in SB and CH with or without FOS for all the strains and mixed-culture except B. bifidum in SB for which maximum counts did not occur. Growth in SB and CH was inhibited (P < .05) for B. infantis with lactulose and B. breve with FOS past 8 h inoculation suggesting that lactulose and FOS were not an alternative to enhance the growth of bifidobacteria in vitro in infant formulas.</p>

Name thesis:degree_name

Master of Science (MS)

Level thesis:degree_level

Thesis - University Access Only

Discipline thesis:degree_discipline

Dairy Science

Year dc:date.available

1994

Author dc:creator

• Dubey, Umesh K.

Contributors dc:contributor

• Vikram V. Mistry

• Bifidobacteria
• Infant formulas
• Growth characteristics
• Growth promoters
• Lactulose
• Fructooligosaccharides
• Dairy Science

Statement dc:rights

• <p>In Copyright - Non-Commercial Use Permitted<br /><a href="http://rightsstatements.org/vocab/InC-NC/1.0/">http://rightsstatements.org/vocab/InC-NC/1.0/</a></p>

Language dc:language

en

Repository record dc:identifier

https://openprairie.sdstate.edu/etd/1470

OAI identifier oai:identifier

oai:openprairie.sdstate.edu:etd-2472