title: Isolation and characterization of an agaro-oligosaccharide (AO)-hydrolyzing bacterium from the gut microflora of Chinese individuals.
abstract: Agarose (AP) from red algae has a long history as food ingredients in East Asia. Agaro-oligosaccharides (AO) derived from AP have shown potential prebiotic effects. However, the human gut microbes responsible for the degradation of AO and AP have not yet been fully investigated. Here, we reported that AO and AP can be degraded and utilized at various rates by fecal microbiota obtained from different individuals. Bacteroides uniformis L8 isolated from human feces showed a pronounced ability to degrade AO and generate D-galactose as its final end product. PCR-DGGE analysis showed B. uniformis to be common in the fecal samples, but only B. uniformis L8 had the ability to degrade AO. A synergistic strain, here classified as Escherichia coli B2, was also identified because it could utilize the D-galactose as the growth substrate. The cross-feeding interaction between B. uniformis L8 and E. coli B2 led to exhaustion of the AO supply. Bifidobacterium infantis and Bifidobacterium adolescentis can utilize one of the intermediates of AO hydrolysis, agarotriose. Growth curves indicated that AO was the substrate that most favorably sustained the growth of B. uniformis L8. In contrast, κ-carrageenan oligosaccharides (KCO), guluronic acid oligosaccharides (GO), and mannuronic acid oligosaccharides (MO) were found to be unusable to B. uniformis L8. Current results indicate that B. uniformis L8 is a special degrader of AO in the gut microbiota. Because B. uniformis can mitigate high-fat-diet-induced metabolic disorders, further study is required to determine the potential applications of AO.
authors.affiliation: Shandong Provincial Key Laboratory of Glycoscience and Glycotechnology, and Key Laboratory of Marine Drugs of Ministry of Education, Ocean University of China, Qingdao, Shandong, China.
authors.forename: Miaomiao
authors.initials: M
authors.lastname: Li
authors.affiliation: Shandong Provincial Key Laboratory of Glycoscience and Glycotechnology, and Key Laboratory of Marine Drugs of Ministry of Education, Ocean University of China, Qingdao, Shandong, China.
authors.forename: Guangsheng
authors.initials: G
authors.lastname: Li
authors.affiliation: State Key Laboratory of Breeding Base for Zhejiang Sustainable Pest and Disease Control, Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou, Zhejiang, China; Key laboratory for Food Microbial Technology of Zhejiang Province, Zhejiang Academy of Agricultural Sciences, Hangzhou, Zhejiang, China.
authors.forename: Liying
authors.initials: L
authors.lastname: Zhu
authors.affiliation: State Key Laboratory of Breeding Base for Zhejiang Sustainable Pest and Disease Control, Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou, Zhejiang, China; Key laboratory for Food Microbial Technology of Zhejiang Province, Zhejiang Academy of Agricultural Sciences, Hangzhou, Zhejiang, China.
authors.forename: Yeshi
authors.initials: Y
authors.lastname: Yin
authors.affiliation: Shandong Provincial Key Laboratory of Glycoscience and Glycotechnology, and Key Laboratory of Marine Drugs of Ministry of Education, Ocean University of China, Qingdao, Shandong, China.
authors.forename: Xiaoliang
authors.initials: X
authors.lastname: Zhao
authors.affiliation: State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, First Affiliated Hospital, Zhejiang University, Hangzhou, Zhejiang, China.
authors.forename: Charlie
authors.initials: C
authors.lastname: Xiang
authors.affiliation: Shandong Provincial Key Laboratory of Glycoscience and Glycotechnology, and Key Laboratory of Marine Drugs of Ministry of Education, Ocean University of China, Qingdao, Shandong, China.
authors.forename: Guangli
authors.initials: G
authors.lastname: Yu
authors.affiliation: State Key Laboratory of Breeding Base for Zhejiang Sustainable Pest and Disease Control, Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou, Zhejiang, China; Key laboratory for Food Microbial Technology of Zhejiang Province, Zhejiang Academy of Agricultural Sciences, Hangzhou, Zhejiang, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Wang
mesh_terms: D000328:Adult; D044466:Asian People; D001419:Bacteria / Q000302:isolation & purification* / Q000378:metabolism*; D005243:Feces / Q000382:microbiology; D005285:Fermentation; D006801:Humans; D006868:Hydrolysis; D007413:Intestinal Mucosa / Q000378:metabolism*; D064307:Microbiota; D009844:Oligosaccharides / Q000378:metabolism*; D012685:Sepharose / Q000378:metabolism*; D055815:Young Adult
chemical_list: D009844:Oligosaccharides; D012685:Sepharose