A preliminary in vitro assessment of GroBiotic®-A, brewer's yeast and fructooligosaccharide as prebiotics for the red drum Sciaenops ocellatus

Abstract

This study examined the effects of brewers yeast, fructooligosaccharide (FOS), and GroBiotic®-A, a mixture of partially autolyzed brewers yeast, dairy components and dried fermentation products, on the intestinal microbial community of red drum, Sciaenops ocellatus. Gastrointestinal (GI) tracts were aseptically removed from three sub-adult red drum previously maintained on a commercial diet and placed in an anaerobic chamber. Intestinal contents were removed, diluted and incubated in vitro in one of four liquid media: normal diet alone, diet + 2% (w/w) GroBiotic®-A, diet + 2% brewers yeast, and diet + 2% FOS. After 24 and 48 h of incubation at 25°C, supernatants were removed for volatile fatty acid (VFA) analysis and DNA was extracted for denaturing gradient gel electrophoresis (DGGE) analysis. Polymerase chain reaction (PCR) was performed on a highly conserved region of M 16S rDNA and the amplicons were subjected to DGGE. The microbial community (MC) fingerprint was used to distinguish microbial populations. The intestinal contents incubated with GroBiotic®-A had significantly (P < 0.05) higher acetate and total VFA concentrations at 48 h compared to the other treatments. DGGE analysis demonstrated that the microbial community was significantly altered by Grobiotic®-A and brewers yeast.

Keywords:

• Prebiotics
• gastrointestinal tract microbes
• anaerobic bacteria
• denaturing gradient gel electrophoresis (DGGE)

Acknowledgments

The authors would like to thank Texas Sea Grant College Program for research funding. We would also like to thank International Ingredient Corporation (St. Louis, MO) for providing GroBiotic®-A and Encore Technologies for providing the FOS. The Texas Parks and Wildlife Marine Development Center provided red drum used in this study. Charles Hernandez (USDA-ARS, Southern Plains) provided technical support and knowledge.

Notes

¹Within column means ± SD (μ mole/ml; n = 3) without a common superscript letter differ significantly (P < 0.05).

²fructooligosaccharide.

³means compared within incubation time.

¹Within column means ± SD (μ mole/ml; n = 3) without a common superscript letter differ significantly (P < 0.05).

² fructooligosaccharide.