| Title | Identification and characterization of a new agar-degrading strain with the novel properties of saccharides inhibition and nitrogen fixation |
|---|---|
| Author | Hao Wu1,2, Guiguang Chen1,2, Yaxi Bian1,2, Wei Zeng1,2, Bihong Sun3, and Zhiqun Liang1,2* |
| Address | 1State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi University, Nanning 530004, P. R. China, 2College of Life Science and Technology, Guangxi University, Nanning 530004, P. R. China, 3The People’s Hospital of Guangxi Zhuang Autonomous Region, Nanning 530021, P. R. China |
| Bibliography | Journal of Microbiology, 55(6),475-482, 2017, |
| DOI | 10.1007/s12275-017-6464-x |
| Key Words | agar-degarding, Streptomyces lavendulae, saccha-rides inhibition, nitrogen fixation |
| Abstract | In this study, a new agar-degrading strain was isolated from soil with agar as a sole carbon source and energy. Based on its morphological, physiological, biochemical characterization and 16S rDNA sequence, the strain was identified as Strep-tomyces lavendulae UN-8. The extracellular agarase activity reached 0.03 U/ml after fermentation in shake flask (250 ml), which was close to other reported non-marine micro-organisms. Furthermore, it is interesting that the growth of UN-8 would be inhibited by glucose (40 g/L) and maltose (40 g/L) with the inhibitory rate of 100% and 70%, respec-tively. Besides, UN-8 could be grown on the solid medium without any nitrogen sources, then the possible nitrogen fix-ation gene nifU was cloned from its genomic DNA. The de-duced amino acid sequence of nifU has high similarity (98%) with nitrogen fixation protein NifU from Streptomyces sp. NRRL S-104 (KJY22454.1) and Streptomyces sp. NRRL F-4428 (KJK52526.1) based on NCBI blast. It is suggested that the nifU gene of UN-8 also encoded nitrogen fixation protein NifU. These results provided some new information for the further understanding of agar-degrading strain. |