title: Diversity of both the cultivable protease-producing bacteria and their extracellular proteases in the sediments of the South China sea.
abstract: Protease-producing bacteria are known to play an important role in degrading sedimentary particular organic nitrogen, and yet, their diversity and extracellular proteases remain largely unknown. In this paper, the diversity of the cultivable protease-producing bacteria and their extracellular proteases in the sediments of the South China Sea was investigated. The richness of the cultivable protease-producing bacteria reached 10(6) cells/g in all sediment samples. Analysis of the 16S rRNA gene sequences revealed that the predominant cultivated protease-producing bacteria are Gammaproteobacteria affiliated with the genera Pseudoalteromonas, Alteromonas, Marinobacter, Idiomarina, Halomonas, Vibrio, Shewanella, Pseudomonas, and Rheinheimera, with Alteromonas (34.6%) and Pseudoalteromonas (28.2%) as the predominant groups. Inhibitor analysis showed that nearly all the extracellular proteases from the bacteria are serine proteases or metalloproteases. Moreover, these proteases have different hydrolytic ability to different proteins, reflecting they may belong to different kinds of serine proteases or metalloproteases. To our knowledge, this study represents the first report of the diversity of bacterial proteases in deep-sea sediments.
authors.affiliation: State Key Lab of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Jinan 250100, People's Republic of China.
authors.forename: Ming-Yang
authors.initials: MY
authors.lastname: Zhou
authors.forename: Xiu-Lan
authors.initials: XL
authors.lastname: Chen
authors.forename: Hui-Lin
authors.initials: HL
authors.lastname: Zhao
authors.forename: Hong-Yue
authors.initials: HY
authors.lastname: Dang
authors.forename: Xi-Wu
authors.initials: XW
authors.lastname: Luan
authors.forename: Xi-Ying
authors.initials: XY
authors.lastname: Zhang
authors.forename: Hai-Lun
authors.initials: HL
authors.lastname: He
authors.forename: Bai-Cheng
authors.initials: BC
authors.lastname: Zhou
authors.forename: Yu-Zhong
authors.initials: YZ
authors.lastname: Zhang
mesh_terms: D044822:Biodiversity; D002681:China; D004269:DNA, Bacterial / Q000235:genetics; D020563:Gammaproteobacteria / Q000145:classification / Q000201:enzymology / Q000235:genetics*; D019015:Geologic Sediments / Q000382:microbiology*; D009792:Oceans and Seas; D010447:Peptide Hydrolases / Q000235:genetics*; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012623:Seawater / Q000382:microbiology; D017422:Sequence Analysis, DNA; D014871:Water Microbiology
chemical_list: D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S; D010447:Peptide Hydrolases