RT Journal Article SR Electronic T1 Characterization of Azotobacter vinelandii and Kits for Its Synthetic Biology Applications JF bioRxiv FD Cold Spring Harbor Laboratory SP 188482 DO 10.1101/188482 A1 King Pong Leung A1 Jacky Fong Chuen Loo A1 Leo Chi U Seak A1 Tung Faat Lai A1 Kevin Yuk Lap Yip A1 Siu Kai Kong A1 Ting Fung Chan A1 King Ming Chan YR 2017 UL http://biorxiv.org/content/early/2017/09/13/188482.abstract AB Azotobacter vinelandii, a Gram-negative aerobic bacterium with an intracellular anaerobic environment that maintains the oxygen-sensitive enzymatic cascades for nitrogen fixation, could be used to express oxygen-sensitive proteins. However, little is known about the properties of A. vinelandii for synthetic biology applications. We therefore first characterized and optimized the conditions for growing and screening BioBrick constructs in A. vinelandii in the presence of 2 antibiotics, ampicillin and chloramphenicol, and then developed two sets of BioBricks for regulated protein expression. The first kit used T7 RNA polymerase, whose expression is under the control of a nitrogen-repressible nifH promoter. The commonly used T7-dependent system in Escherichia coli can then be used in A. vinelandii. Because its intracellular anaerobic environment is favorable for processes such as magnetosome biogenesis, we attempted to migrate the biogenesis machineries from the magnetotactic bacterium Magnetospirillum gryphiswaldense to A. vinelandii. During this undertaking, another insertion kit construct was developed to allow protein conjugation onto magnetosomes. The kit consists of mamC, a gene encoding a transmembrane protein on magnetosomes, and multiple restriction sites downstream of mamC for fusing a gene of interest. This insertion kit allows the attachment of any desired protein onto the magnetosome membrane by fusing with the mamC protein. We demonstrated the function of this kit by fusing mamC to a GFP nanobody. This kit will facilitate the conjugation of any target protein onto magnetosomes for downstream applications in the future.Financial Disclosure We received sponsorship from the 2012–15 Teaching Development Grants Triennium, Faculty of Engineering and Biochemistry Program, School of Life Sciences, The Chinese University of Hong Kong. The funders had no role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript.Competing Interests The authors declare that no competing interests exist.Ethics Statement N/A.Data Availability All data are fully available without restriction.