2.1 Microorganisms and chemicals
Escherichia coli BL21(DE3)pLysS (Invitrogen) was purchased from Thermo Fisher Scientific Japan (Tokyo, Japan). The pRSET-EmGFP bacterial expression vector was purchased from Thermo Fisher Scientific Japan. The vector pRSET-EmGFP was introduced to E. coli BL21(DE3)pLysS using the standard method in the users’ manual. The strain was cultivated in LB broth that included 10 g/L Bacto® Tryptone (Becton Dikinson and Co. (BD) Japan, Tokyo, Japan), 5 g/L Bacto® yeast extract (BD), and 10 g/L NaCl. The culture was incubated overnight at 37°C with shaking at 200 rpm. This was the inoculum used in the experiments. The culture broth was stored as frozen stocks with 30% glycerol in a deep freezer at −80°C. Experimental-grade yeast extracts were purchased from BD, Millipore Sigma Japan (Tokyo, Japan), Kyokuto Pharmaceutical Industrial Co. Ltd. (Tokyo, Japan), and Nihon Pharmaceutical Co. Ltd. (Tokyo, Japan), and referred to as E1, E2, E3, and E4, respectively. Manufacturing-grade yeast extracts were provided by manufacturers including Oriental Yeast Co. Ltd. (Tokyo, Japan), Nihon Paper (Tokyo, Japan), and named as M1, M2, M3, and M4.