TY - JOUR
T1 - Two extracellular sialidases from Bifidobacterium bifidum promote the degradation of sialyl-oligosaccharides and support the growth of Bifidobacterium breve
AU - Nishiyama, Keita
AU - Nagai, Aki
AU - Uribayashi, Kazuya
AU - Yamamoto, Yuji
AU - Mukai, Takao
AU - Okada, Nobuhiko
N1 - Funding Information:
This study was supported by the Grant-in-Aid for Young Scientists (Start-up) [no. 15H06581 to K.N.] and a Grant-in-Aid for Young Scientists (B) [no. 17K15249 to K.N.] from the Japan Society for the Promotion of Science , by a Kitasato University Research Grant for Young Researchers (to K.N.), and by the Institute for Fermentation, Osaka (IFO) (to K.N.). The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Publisher Copyright:
© 2018 Elsevier Ltd
PY - 2018/8
Y1 - 2018/8
N2 - We investigated the roles of extracellular sialidases (SiaBb1 and SiaBb2) in cross-feeding between sialidase-carrying Bifidobacterium bifidum and sialic acid-utilizing Bifidobacterium breve. Using 6ʹ sialyllactose (6ʹSL) as a carbon source, the number of wild-type B. bifidum cells increased while that of a siabb2-inactivated strain (Δsiabb2) did not. Coculture of these two strains in the presence of 6ʹSL resulted in similar increase in cell numbers. Coculture of wild-type B. bifidum, but not the Δsiabb2 strain, with sialic acid-utilizing Bifidobacterium breve, which cannot release sialic acids from carbohydrates, in the presence of 6ʹSL increased the number of B. breve cells. Moreover, when mucin was used as a carbon source, B. breve growth was increased in cocultures with B. bifidum wild-type and Δsiabb2 strains, suggesting that SiaBb1 may be involved. Additionally, B. breve cell numbers increased during cultivation with recombinant SiaBb1-and SiaBb2-treated mucin as the sole carbon source. These results indicated that B. bifidum SiaBb2 liberated sialic acid from sialyl-human milk oligosaccharides and -mucin glycans, supporting the growth of B. breve through sialic acid cross-feeding. SiaBb1 may assist in the degradation of mucin glycan. Collectively, our results revealed that both the B. bifidum extracellular sialidases promote the utilization of sialylated carbohydrates and supply free sialic acid to other Bifidobacterium strains.
AB - We investigated the roles of extracellular sialidases (SiaBb1 and SiaBb2) in cross-feeding between sialidase-carrying Bifidobacterium bifidum and sialic acid-utilizing Bifidobacterium breve. Using 6ʹ sialyllactose (6ʹSL) as a carbon source, the number of wild-type B. bifidum cells increased while that of a siabb2-inactivated strain (Δsiabb2) did not. Coculture of these two strains in the presence of 6ʹSL resulted in similar increase in cell numbers. Coculture of wild-type B. bifidum, but not the Δsiabb2 strain, with sialic acid-utilizing Bifidobacterium breve, which cannot release sialic acids from carbohydrates, in the presence of 6ʹSL increased the number of B. breve cells. Moreover, when mucin was used as a carbon source, B. breve growth was increased in cocultures with B. bifidum wild-type and Δsiabb2 strains, suggesting that SiaBb1 may be involved. Additionally, B. breve cell numbers increased during cultivation with recombinant SiaBb1-and SiaBb2-treated mucin as the sole carbon source. These results indicated that B. bifidum SiaBb2 liberated sialic acid from sialyl-human milk oligosaccharides and -mucin glycans, supporting the growth of B. breve through sialic acid cross-feeding. SiaBb1 may assist in the degradation of mucin glycan. Collectively, our results revealed that both the B. bifidum extracellular sialidases promote the utilization of sialylated carbohydrates and supply free sialic acid to other Bifidobacterium strains.
KW - Bifidobacterium
KW - Colonization
KW - Sialic acid
KW - Sialidase
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U2 - 10.1016/j.anaerobe.2018.05.007
DO - 10.1016/j.anaerobe.2018.05.007
M3 - Article
C2 - 29787815
AN - SCOPUS:85049298843
VL - 52
SP - 22
EP - 28
JO - Anaerobe
JF - Anaerobe
SN - 1075-9964
ER -
