Location: Renewable Product Technology ResearchTitle: Effect of fermentation with Saccharomyces cerevisiae strain PJ69-4 on the phytic acid, raffinose, and stachyose contents of soybean meal) Author
Submitted to: Animal Feed Science And Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/1/2013
Publication Date: 9/20/2013
Publication URL: http://handle.nal.usda.gov/10113/61952
Citation: Tudor, K.W., Jones, M.A., Hughes, S.R., Holt, J.P., Wiegand, B.R. 2013. Effect of fermentation with Saccharomyces cerevisiae strain PJ69-4 on the phytic acid, raffinose, and stachyose contents of soybean meal. The Professional Animal Scientist. 29:529-534. Interpretive Summary: This manuscript describes using a strain of baker’s yeast strain to identify a safe microorganism that is capable of reducing levels of phosphorus excreted by farm animals. Soybean meal has high levels of phytic acid, an unusable source of phosphorous. In this research, soybean meal fermented with two different strains of yeast were compared. Both test strains reduced phytic acid levels to near or below detectable level. This research is expected to impact the feed industry by providing a way to make new animal feed, through these fermentations, that will slightly increase total phosphorus, reduce fructose, and remove phytic acid, sucrose, raffinose and stachyose. This will result in a more useful animal feed, potentially capable of significant increases in animal body weight for market when placed in feeding lot scenarios.
Technical Abstract: Three experiments were conducted to determine the impact of submerged fermentation procedures using Saccharomyces cerevisiae baker’s yeast strain PJ69-4a on degradation of phytic acid and the raffinosaccharides, raffinose, and stachyose, in soybean meal. The goal of the research was to identify a non-toxin producing microorganism that is capable of reducing levels of phosphorus-containing phytate excreted by farm animals. In the first experiment, soybean meal fermented with S. cerevisiae strain PJ69-4a yeast (diploid) was compared with soybean meal fermented with S. cerevisiae strain PJ69-4a yeast cloned with the PHO5 gene to potentially increase phytase activity. Both treatments reduced phytic acid levels to near or below detectable levels. Total phosphorus values were the same for all samples. In the second experiment, a 150-gram batch of fermented soybean meal was compared with a 450-gram batch similarly fermented. After fermentation, the amounts of total phosphorus, phytic acid, fructose, and total sugars were lower in the 450-gram batch compared to the 150-gram batch. The amounts of sucrose, raffinose, and stachyose were reduced below detectable levels in both the large and small batches. In the third experiment, 60-gram samples from 450-gram batches of fermented soybean meal were compared with 60-gram samples of non-fermented, heated soybean meal, and 60-gram samples of non-heated, non-fermented soybean meal. Fermentation increased total phosphorus slightly, reduced fructose very slightly, and reduced phytic acid, sucrose, raffinose, and stachyose below detectable levels compared to non-fermented samples. Heating had little impact on total phosphorus, phytic acid, and selected carbohydrates compared to non-heated, non-fermented samples. Most importantly, heating alone did not reduce phytic acid to levels observed with fermentation. Results indicated that submerged fermentation of soybean meal with baker’s yeast S. cerevisiae PJ69-4a can effectively degrade phytic acid in addition to the raffinosaccharides, raffinose, and stachyose.