title: Horizontal Transfer of a Novel Soil Agarase Gene from Marine Bacteria to Soil Bacteria via Human Microbiota.
abstract: Seaweed is receiving an increasing amount of attention as a "sea vegetable". The microbiota of coastal populations may acquire seaweed associated enzymes through marine food. Several agarases have been found in non-marine environments; however, their origin is unknown. In this study, a hypothetical protein, Aga1, was identified as an agarase from an inland soil agar-degrading bacterium, Paenibacillus sp. SSG-1.Having low similarity to known glycoside hydrolases, Aga1 may be a distant member of the glycoside hydrolase family 86. Aga1 has good pH stability (pH 3-11) and is stable in the presence of various metal ions. Aga1 is an exo-type β-agarase that produces NA 4 (neoagarotetraose) and NA 6 (neoagarohexaose) as its main products. In addition, Aga1 may be a cell-surface-binding protein. The bioinformatic analysis showed aga1 may have been transfered together with its surrounding genes, from marine bacteria to soil bacteria via human microbiota. The use of seaweed as food and the disposal of human faeces or saliva were the most likely reasons for this gene transfer pathway. Notably, the results also indicated that microbes from inland humans may degrade agar and that these microbes may have acquired seaweed associated genes because of increased seaweed in diets.
authors.affiliation: Microbiology and Metabolic Engineering of Key Laboratory of Sichuan Province, College of Life Sciences, Sichuan University, Chengdu, 610065, P. R. China.
authors.forename: Tao
authors.initials: T
authors.lastname: Song
authors.affiliation: Microbiology and Metabolic Engineering of Key Laboratory of Sichuan Province, College of Life Sciences, Sichuan University, Chengdu, 610065, P. R. China.
authors.forename: Hui
authors.initials: H
authors.lastname: Xu
authors.affiliation: Microbiology and Metabolic Engineering of Key Laboratory of Sichuan Province, College of Life Sciences, Sichuan University, Chengdu, 610065, P. R. China.
authors.forename: Congchong
authors.initials: C
authors.lastname: Wei
authors.affiliation: Microbiology and Metabolic Engineering of Key Laboratory of Sichuan Province, College of Life Sciences, Sichuan University, Chengdu, 610065, P. R. China.
authors.forename: Tengfei
authors.initials: T
authors.lastname: Jiang
authors.affiliation: Microbiology and Metabolic Engineering of Key Laboratory of Sichuan Province, College of Life Sciences, Sichuan University, Chengdu, 610065, P. R. China.
authors.forename: Shishang
authors.initials: S
authors.lastname: Qin
authors.affiliation: Microbiology and Metabolic Engineering of Key Laboratory of Sichuan Province, College of Life Sciences, Sichuan University, Chengdu, 610065, P. R. China.
authors.forename: Weijia
authors.initials: W
authors.lastname: Zhang
authors.affiliation: Microbiology and Metabolic Engineering of Key Laboratory of Sichuan Province, College of Life Sciences, Sichuan University, Chengdu, 610065, P. R. China.|National Engineering Research Center for Biomaterials, Sichuan University, Chengdu, 610065, P. R. China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Cao
authors.affiliation: Microbiology and Metabolic Engineering of Key Laboratory of Sichuan Province, College of Life Sciences, Sichuan University, Chengdu, 610065, P. R. China.
authors.forename: Chao
authors.initials: C
authors.lastname: Hu
authors.affiliation: Microbiology and Metabolic Engineering of Key Laboratory of Sichuan Province, College of Life Sciences, Sichuan University, Chengdu, 610065, P. R. China.
authors.forename: Fan
authors.initials: F
authors.lastname: Zhang
authors.affiliation: Microbiology and Metabolic Engineering of Key Laboratory of Sichuan Province, College of Life Sciences, Sichuan University, Chengdu, 610065, P. R. China.
authors.forename: Dairong
authors.initials: D
authors.lastname: Qiao
authors.affiliation: Microbiology and Metabolic Engineering of Key Laboratory of Sichuan Province, College of Life Sciences, Sichuan University, Chengdu, 610065, P. R. China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Cao
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D000069196:Gastrointestinal Microbiome; D022761:Gene Transfer, Horizontal / Q000502:physiology*; D006026:Glycoside Hydrolases / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D056507:Paenibacillus / Q000201:enzymology / Q000235:genetics; D012988:Soil Microbiology; D014871:Water Microbiology
chemical_list: D001426:Bacterial Proteins; D006026:Glycoside Hydrolases; C019624:agarase