sterilized plastic bottles were used for the samples intended for the bioassays.
For the latter samples, a primary filtration using a 0.45 μm filter was carried out on the sampling day.
Samples were stored at - 20 °C until transport to Japan inside an icebox to the laboratory where the same conditions were maintained.
A secondary filtration using a 0.22 μm filter is required prior to use in the bioassays following pH adjustment between 3 and 6.