Biosynthesis of Thermoresponsive Magnetic Nanoparticles by Magnetosome Display System.

Thermoresponsive magnetic nanoparticles (MNPs) were synthesized using a magnetosome display system. An elastin-like polypeptide decamer of VPGVG (ELP10), which is hydrophobic above the transition temperature ( Tt) and can form an insoluble aggregation, was immobilized on biogenic MNPs in the magnetotactic bacterium, Magnetospirillum magneticum AMB-1. It was suggested that hydrophobicity of the MNP surface increased at 60 °C compared with 20 °C by the immobilization of ELP10. Size distribution analysis indicated that the immobilization of ELP10 onto MNPs induced the increased hydrophobicity with increasing temperatures up to 60 °C, promoting aggregation of the particles by hydrophobic and magnetic interactions. These results suggest that the acceleration of magnetic collection at 60 °C was caused by particle aggregation promoted by hydrophobic interaction between ELP-MNPs. Furthermore, the immobilization of ELP on MNPs gave a quick magnetic collection at 60 °C by external magnetic field. The thermoresponsive properties will further expand the utility of biotechnological applications of biogenic MNPs.

Production of ω3 fatty acids in marine cyanobacterium Synechococcus sp. strain NKBG 15041c via genetic engineering.

Omega-3 fatty acids (ω3 FAs) have attracted attention because they have various health benefits for humans. Fish oils are currently major sources of ω3 FAs, but a sustainable supply of ω3 FAs based on fish oils is problematic because of the increasing demand. In this study, the production potential of a genetically engineered marine cyanobacterium, Synechococcus sp. strain NKBG 15041c, was examined as an alternative source of ω3 FAs. A change in fatty acid composition of this cyanobacterium was successfully induced by the expression of a heterologous Δ6-desaturase, and the transformants synthesized stearidonic acid, which the wild type cannot produce. As a result of optimization of culture conditions, maximal contents of stearidonic acid and total ω3 FAs reached 12.2 ± 2.4 and 118.1 ± 3.5 mg/g, respectively. The maximal ω3 FA productivity was 4.6 ± 0.7 mg/(L⋅day). These are the highest values of the contents of stearidonic acid and ω3 FAs in genetically engineered cyanobacteria reported thus far. Therefore, genetically engineered Synechococcus sp. strain NKBG 15041c may be a promising sustainable source of ω3 fatty acids.

Draft Genome Sequence of Marine Cyanobacterium Synechococcus sp. Strain NKBG042902, Which Harbors a Homogeneous Plasmid Available for Metabolic Engineering.

The marine cyanobacterium Synechococcus sp. strain NKBG042902 was isolated from coastal areas in Japan. Strain NKBG042902 has four plasmids: pSY8, pSY9, pSY10, and pSY11. Moreover, the hybrid plasmid pUSY02 containing pSY11 and Escherichia coli plasmid pUC18 was constructed for this strain. The genetic manipulation technique using pUSY02 was established for this strain and used in metabolic engineering. Here, we report the draft genome sequence of this strain, which has 77 contigs comprising a total length of 3,319,479 bp, with a G+C content of 49.4%.

[Analgesic efficacy of transversus abdominis plane block after open abdominal aortic aneurysm surgery].

BACKGROUND: Ultrasound (US)-guided transversus abdominis plane (TAP) block is widely-spread analgesic technique for the patients undergoing abdominal surgery and can be provided safely for the patients receiving anticoagulation therapy. We conducted a retrospective comparative trial of analgesic efficacy between the patient who received US-guided TAP block with postoperative continuous iv-fentanyl infusion (group T) and those who received epidural analgesia (group E). METHODS: Twenty three patients who had undergone abdominal aortic replacement were analyzed retrospectively. The number of patients in group T was 12, and those in group E was 11. The postoperative first ambulation day, the postoperative first oral feeding day, the length of hospital stay, the use of rescue analgesic medication, and the incidence of postoperative nausea and vomiting (PONV) were compared between the two groups. P<0.05 was considered significant RESULTS: There were no significant differences in baseline characteristics between the two groups. There were no significant differences in postoperative first ambulation day (P=0.97), the postoperative first oral feeding day (P=0.46), the length of hospital stay (P= 0.32), the number of times of rescue analgesic medication (P=0.55), and the incidence of PONV between the two groups. CONCLUSIONS: US-guided TAP block is a useful option as analgesic technique for patients undergoing abdominal aortic replacement