Because the PSII core complexes from the D2-K317R mutant retained a relatively high O2 evolution rate [2000 2900 μmol of O2 (mg of Chl)−1 h–1] and the FTIR spectra in the solution sample of the K317R mutant exhibited better S-state cycling, this observation indicates that the sensitivity of the S3 → S0 transition to sample dehydration is increased by the K317R mutation.
However, conventional SEM requires dehydration and metal coating of biological samples before observation, and because biofilms consist mainly of water, sample dehydration may influence the biofilm structure.
Caution was taken to avoid sample dehydration.
After several washes and drying by dehydration, samples were digested with trypsin (Promega, Madison, WI) as described previously [31].
RF heating of solid-state biological samples is known to be a destabilizing factor in high-field NMR experiments that shortens the sample lifetime by continuous dehydration during the high-power cross-polarization and decoupling pulses.
The decrease in the intensity of the 1748 cm 1 band by dehydration of the sample was previously reported by Service et al. in the PSII core complexes of WT Synechocystis.
It has been proposed that these fibrous structures are caused by the dehydration process in conventional sample preparation methods, so it appears that the biofilm structure observed after IL treatment has retained its form better than when the conventional method is used.
Afterwards, samples were dried by critical-point dehydration with carbon dioxide, followed by sputtering (Baltec SCD 10) with 5 nm gold-palladium.
Color development was performed with DAB for 3 to 5 min for all samples, followed by hematoxylin counterstaining, dehydration, and coverslipping.
Glutaraldehyde-fixed samples were washed in buffer, followed by dehydration in a graded series of ethanol concentrations.
The samples were then post-fixed by 1% OsO4 for 2 h, followed by dehydration in a graded ethanol series (30%, 50 %, 70 %, 90 % and 100
