Lagoon Notoro-ko is a large brackish lake on the Okhotsk Sea coast of Hokkaido. It is completely covered with sea ice during winter and the hydrographic and biological conditions during this season are unknown. We conducted a winter investigation into the temporal changes of chlorophyll a and environmental variables in the sea ice and water column beneath the surface during the period from February 6 to April 5, 2012. Integrated chlorophyll a at 18 m ranged 22.4-295.6 mg/m2. In contrast, chlorophyll a levels in 24-45 cm thick ice ranged 0.2-8.6 mg/m2, or relatively less than in the water column. However, because chlorophyll a was largely concentrated in the bottom-most part of the ice, it might be available to grazers in the underlying water. While the ice is melting, a large proportion of the populations released from the ice likely sink to the sea bottom rather than remaining in the water column. During the ice melting period, a large part of the populations released from the ice likely sink to the sea bottom rather than stayed in the water column. In summary, it can be said that the ice is a unique ecological platform, where microalgae perform the three roles of the primary producers, i.e., to produce rich products（pasture）, to avail grazers to feed on the products（meadow）and to send the products to a benthic community（feeder）.
Lagoon Notoro-ko is open to the Okhotsk Sea and freeze during the winter. We conducted a winter investigation into the temporal changes of particulate matters flux and chlorophyll a in sea ice and water column during the ice-covered period from February 13 to April 5, 2012. We speculated that the majority of particulate matter flux during the sea ice growth phase originated from the phytoplankton in the water column. During the transition period the majority of the sinking particulate matter was considered to be ice algae, and during the sea ice melting period, ice algae and phytoplankton contributed to an increase of sinking particulate matter.
Halophiles produce halophilic enzymes which function well in high salinity conditions. The starch binding domain（SBD）of halophilic α-amylase has been found to show typical halophilic characteristics with high aqueous solubility and folding capacity. Here we developed a fusion protein expression vector, pSBF-S1, using this SBD as a fusion partner, looking for highly soluble protein expression and efficient affinity-purification. The fusion protein expressed could be purified by dual affinity chromatographies, i.e. Ni-affinity resin with N-terminal His-tag and amylose-resin with SBD affinity. The target protein is then generated through thrombin-digestion of fusion protein at the cleavage site between the target protein and SBD.