■日時： 2012 年 9 月 25 日（火）13:00～14:00■会場： 新潟大学農学部 A506-2■主催： 新潟大学企画戦略本部若手研究者育成推進室■協賛： 新潟大学地域連携フードサイエンスセンター

「A snapshot of oligosaccharide andpolysaccharide catabolism in two widelyused probiotic bacteria」○

Associate Professor Maher Abou Hachem
The Technical University of Denmark■Career SummaryMaher Abou Hachem has obtained his MSc in chemical engineering from theUniversity of Lund, Sweden in 1998 and his PhD in Biotechnology from the same
University in 2003. Thereafter, Maher Abou Hachem Joined the Carlsberg Laboratory inCopenhagen, for a short post-doctoral research project. In 2004, Maher Joined theTechnical University of Denmark as a post-doctoral fellow at the Laboratory ofProfessor Birte Svensson, where he in 2008 was appointed as an Associate Professor inFood Protein Chemistry, and he is still active in this position.
■Research Areas
Carbohydrate active enzymes/proteins from probiotics, and catabolism of carbohydrateprebiotics.
Modular glycoside hydrolases and carbohydrate binding modules active onhemi-cellulose and starch.
Enzymology and interactions of carbohydrate active proteins with carbohydrate
substrates/inhibitors/metal-ion ligands.
■Academic Society Affiliation■Main Publications
1. Abou Hachem, M., Karlsson, E.N., Simpson, P.J., Williamson, M.P., Seller, P., Linse,S., Gilbert, H.J., Bolam D.N., and Holst, O. (2002) Calcium binding andthermodynamic studies on the thermostable carbohydrate binding modules of Xyn10A
Rhodothermus marinus. Biochemistry 41, 5720-5729
2. Christiansen, C., Abou Hachem, M., Janeček, S., Viksø-Nielsen, A., Blennow, A., Svensson,B. (2009) The carbohydrate binding module family 20 - diversity, structure and function. FEBSJ 276, 5006-5029.

3. Fredslund, F., Abou Hachem, M., Jonsgaard Larsen, R., Gerd Sørensen, P., Coutinho,P.M., Lo Leggio, L. and Svensson, B. (2011) Crystal structure of α-galactosidase from
Lactobacillus acidophilus NCFM: insight into tetramer formation and substrate binding.
JMB 412, 466-480
4. Andersen J.M., Barrangou R., Abou Hachem M., Lahtinen S., Goh Y.-J., Svensson
B., Klaenhammer T. R. (2011) Transcriptional and functional analysis ofgalactooligosaccharide uptake by lacS in Lactobacillus acidophilus PNAS 108,2651-2655
5. Møller M.S., Fredslund, F., Majumder, A., Nakai H., Poulsen, J.-C. N., Lo Leggio, L.,
Svensson, B., Abou Hachem, M. (2012) Enzymology and structure of the GH13_31
glucan 1,6-α-glucosidase that confers isomaltooligosaccharide utilisation in the
probiotic Lactobacillus acidophilus NCFM J. Bacteriol (In press)○○○○○○○○○○○○○○○○Abstract○○○○○○○○○○○○○○○○The interplay between diet and probiotic bacteria, mainly from the Lactobacillus andBifidobacterium genera, has a major impact on human health e.g. pathogen protection,certain gastroinestinal disorders, cancers and allergic disorders [1]. Carbohydrateprebiotics comprising mainly non-digestible oligosaccharides but also a few
polysaccharides, alter the balance between gut microbiota by selectively stimulating thegrowth of probiotics. Thus, carbohydrate catabolism and transport has been implicatedas an attribute of probiotic action [2]. To shed light on this facet of probiotics, we haveinvestigated the utilization various glycosides in the two model commercial probiotics
strains Lactobacillus acidophilus NCFM and Bifidobacterium animalis subsp. lactis
Bl-04 using proteomic and transcriptomic techniques. Selected target enzymes andproteins were heterologously produced and characterized. Results from this study will
be presented with focus on the routes of utilization of α-glucosides and galactosides inthese two organisms. These results suggest the presence of diverse routes of utilizationof studied saccharides with respect to hydrolases and transport proteins. Interestingly,
our results show that the utilization of related glycosides is sometime linked on thegenetic, transcriptional and sometimes on the protein levels.
1O'Flaherty, S. and Klaenhammer, T. R. (2010) The role and potential of probiotic

bacteria in the gut, and the communication between gut microflora and gut/host.
International Dairy Journal. 20, 262-268
2Fukuda, S., Toh, H., Hase, K., Oshima, K., Nakanishi, Y., Yoshimura, K., Tobe, T.,

Clarke, J. M., Topping, D. L., Suzuki, T., Taylor, T. D., Itoh, K., Kikuchi, J., Morita, H.,
Hattori, M. and Ohno, H. (2011) Bifidobacteria can protect from enteropathogenic infection
through production of acetate. Nature. 469, 543-U791