Seminar

Seminar

Transferability of plasmids in various environmental conditions

Title Transferability of plasmids in various environmental conditions
Lecturer Dr. Masaki (Masa) Shintani (Associate Professor, Graduate School of Integrated Science and Technology, Shizuoka University)
Language English
Date&Time 05/09/2017 (Tue) 15:00~16:00
Venue Large Seminar Room
Detail A self-transmissible plasmid is a major ‘vehicle’ of genes including antibiotic resistance genes and/or catabolic genes by spreading among different microbial cells. Transferability of plasmids in different conditions is important not only to understand how the microbes have been evolved and adapted to various environments, but also to develop a new technology to regulate the spread of genes in microbial community. The objective of our study is to understand the behaviors of plasmids (their stability and transferability) in natural environment. Monitoring plasmid transfers in model environmental samples and one-on-one mating assays showed that the presence of divalent cations (Ca2+ and Mg2+) could promote transfer of plasmids belonging to incompatibility group (=plasmid classification) P-1, P-7, and P-91,2). Single-cell-level analyses could detect ‘transient’ hosts of plasmids, which could not necessarily maintain the plasmid. This fact suggests that donor might transfer its plasmid to different recipient candidates until finding appropriate hosts that can replicate and stably maintain the plasmid3). Nucleotide-associated proteins (NAPs), which was encoded by genes both on an IncP-7 plasmid and its host chromosome, were shown to be important for the IncP-7 plasmid maintenance in its host and transfer2,4). The NAPs genes were similarly encoded on other plasmids, indicating that they have an important role for plasmid behaviors in different hosts5). We successfully found environmental-, plasmid- and host-factors that affected the behaviors of plasmids. 1) Shintani et al., 2008. Behavior of the IncP-7 carbazole-degradative plasmid pCAR1 in artificial environmental samples. Applied Microbiology and Biotechnology, 80: 485-497. 2) Shintani, 2017. The behavior of mobile genetic elements (MGEs) in different environments. Bioscience, Biotechnology, and Biochemistry, 81:854-862. 3) Shintani et al., 2014. Single-cell analyses revealed transfer ranges of IncP-1, IncP-7, and IncP-9 plasmids in a soil bacterial community. Applied and Environmental Microbiology, 80:138-145. 4) Suzuki-Minakuchi et al., 2015. Effects of three different nucleoid-associated proteins encoded on IncP-7 plasmid pCAR1 on host Pseudomonas putida KT2440. Applied and Environmental Microbiology, 81: 2869-2880. 5) Shintani et al., 2015. Nucleoid-associated proteins encoded on plasmids: Occurrence and mode of function. Plasmid, 80:32-44.
Contact ストレス微生物科学
高木 博史 (hiro@bs.naist.jp)

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