TY - JOUR
T1 - Lactobacillus gasseri requires peptides, not proteins or free amino acids, for growth in milk
AU - Arakawa, K.
AU - Matsunaga, K.
AU - Takihiro, S.
AU - Moritoki, A.
AU - Ryuto, S.
AU - Kawai, Y.
AU - Masuda, T.
AU - Miyamoto, T.
N1 - Funding Information:
We are grateful to a volunteer who provided breast milk and the kind researchers at Godo Shusei Co. for the provision of bromelain and papain. We also thank Y. Omori, H. Takeda, C. Hano, and H. Mineyuki (Faculty of Agriculture, Okayama University) for their assistance with several measurements. This work was funded by a research grant of the Institute for Fermentation, Osaka, to K. Arakawa and the Grant-in-Aid for Young Scientists (B; no. 26870393 ) from the Japan Society for the Promotion of Science to K. Arakawa.
Publisher Copyright:
© 2015 American Dairy Science Association.
PY - 2015/3/1
Y1 - 2015/3/1
N2 - Lactobacillus gasseri is a widespread commensal lactic acid bacterium inhabiting human mucosal niches and has many beneficial effects as a probiotic. However, L. gasseri is difficult to grow in milk, which hurts usability for the food industry. It had been previously reported that supplementation with yeast extract or proteose peptone, including peptides, enables L. gasseri to grow well in milk. In this study, our objective was to confirm peptide requirement of L. gasseri and evaluate efficacy of peptide release by enzymatic proteolysis on growth of L. gassei in milk. Three strains of L. gasseri did not grow well in modified DeMan, Rogosa, Sharpe broth without any nitrogen sources (MRS-N), but addition of a casein-derived peptide mixture, tryptone, promoted growth. In contrast, little effect was observed after adding casein or a casein-derived amino acid mixture, casamino acids. These results indicate that L. gasseri requires peptides, not proteins or free amino acids, among milk-derived nitrogen sources for growth. Lactobacillus gasseri JCM 1131T hardly had growth capacity in 6kinds of milk-based media: bovine milk, human milk, skim milk, cheese whey, modified MRS-N (MRSL-N) supplemented with acid whey, and MRSL-N supplemented with casein. Moreover, treatment with digestive proteases, particularly pepsin, to release peptides made it grow well in each milk-based medium. The pepsin treatment was the most effective for growth of strain JCM 1131T in skim milk among the tested food-grade proteases such as trypsin, α-chymotrypsin, calf rennet, ficin, bromelain, and papain. As well as strain JCM 1131T, pepsinolysis of milk improved growth of other L. gasseri strains and some strains of enteric lactobacilli such as Lactobacillus crispatus, Lactobacillus gallinarum, Lactobacillus johnsonii, and Lactobacillus reuteri. These results suggest that some relatives of L. gasseri also use peptides as desirable nitrogen sources, and that milk may be a good supplier of nutritious peptides to enteric lactobacilli including L. gasseri after peptic digestion in the gastrointestinal tract. This is the first report showing peptide requirement of L. gasseri and efficacy of pepsinolysis on the growth of L. gasseri and its relatives in milk. This study would contribute to increasing usability of L. gasseri and its relatives as probiotics in dairy foods.
AB - Lactobacillus gasseri is a widespread commensal lactic acid bacterium inhabiting human mucosal niches and has many beneficial effects as a probiotic. However, L. gasseri is difficult to grow in milk, which hurts usability for the food industry. It had been previously reported that supplementation with yeast extract or proteose peptone, including peptides, enables L. gasseri to grow well in milk. In this study, our objective was to confirm peptide requirement of L. gasseri and evaluate efficacy of peptide release by enzymatic proteolysis on growth of L. gassei in milk. Three strains of L. gasseri did not grow well in modified DeMan, Rogosa, Sharpe broth without any nitrogen sources (MRS-N), but addition of a casein-derived peptide mixture, tryptone, promoted growth. In contrast, little effect was observed after adding casein or a casein-derived amino acid mixture, casamino acids. These results indicate that L. gasseri requires peptides, not proteins or free amino acids, among milk-derived nitrogen sources for growth. Lactobacillus gasseri JCM 1131T hardly had growth capacity in 6kinds of milk-based media: bovine milk, human milk, skim milk, cheese whey, modified MRS-N (MRSL-N) supplemented with acid whey, and MRSL-N supplemented with casein. Moreover, treatment with digestive proteases, particularly pepsin, to release peptides made it grow well in each milk-based medium. The pepsin treatment was the most effective for growth of strain JCM 1131T in skim milk among the tested food-grade proteases such as trypsin, α-chymotrypsin, calf rennet, ficin, bromelain, and papain. As well as strain JCM 1131T, pepsinolysis of milk improved growth of other L. gasseri strains and some strains of enteric lactobacilli such as Lactobacillus crispatus, Lactobacillus gallinarum, Lactobacillus johnsonii, and Lactobacillus reuteri. These results suggest that some relatives of L. gasseri also use peptides as desirable nitrogen sources, and that milk may be a good supplier of nutritious peptides to enteric lactobacilli including L. gasseri after peptic digestion in the gastrointestinal tract. This is the first report showing peptide requirement of L. gasseri and efficacy of pepsinolysis on the growth of L. gasseri and its relatives in milk. This study would contribute to increasing usability of L. gasseri and its relatives as probiotics in dairy foods.
KW - Lactobacillus gasseri
KW - Pepsin
KW - Peptide requirement
KW - Proteolysis
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U2 - 10.3168/jds.2014-8860
DO - 10.3168/jds.2014-8860
M3 - Article
C2 - 25529420
AN - SCOPUS:84924025490
VL - 98
SP - 1593
EP - 1603
JO - Journal of Dairy Science
JF - Journal of Dairy Science
SN - 0022-0302
IS - 3
ER -