羟基自由基致死小新月菱形藻的生化机制

 船舶压载水中悬浮微藻的去除一直是一个难题。本文以小新月菱形藻（Nitzschia closterium minutissima）为压载水代表生物，研究了羟基自由基致死小新月菱形藻的生化机制。结果表明，当小新月菱形藻的浓度为1.2×106/mL时，致死小新月菱形藻的羟基溶液浓度范围为0.81~0.91mg/L。羟基自由基对小新月菱形藻的致死机制是对细胞蛋白质、藻糖和叶绿素等大分子的破坏，使其无法再生，从而达到压载水排放的生物量要求。

Biochemical Mechanism of Killing Nitzschia closterium minutissima by Hydroxyl Radicals

It has always been an important issue to remove suspended algae in ship's ballast water. The ballast water discharge process is the main cause of pest spreads in a body of water of geographic isolation. The treatment of micro-organisms in ballast water by hydroxyl radicals is based on the advanced oxidation technology, a new method, that will not adversely affect the water environment. Hydroxyl radical is similar to fluorine in oxidation capability, and is one of the most offensive chemicals, and can react with different types of organic and inorganic matters. With Nitzschia closterium minutissima as biological representatives in ballast water, this paper mainly study the biochemical reaction mechanism of killing Nitzschia closterium minutissima by the hydroxyl radicals. Tests for dead Nitzschia closterium minutissima concentrations were carried out with increase of hydroxyl radical concentration, to observe the changes of biological macromolecules of protein, glucose and chlorophyll. Results show that when the concentration of Nitzschia closterium minutissima reaches 1.2×106/mL, the concentration range of dead Nitzschia closterium minutissima hydroxyl is 0.81~0.91mg/L. When the hydroxyl radical solution reaches progressively the concentration of 0.7mg/L, 99% of Nitzschia closterium minutissima can be killed, with no regeneration after 24 hours. The lower rate of protein and glucose shows a further decrease after an initial increase and chlorophyll is in the trend of reducing. Hydroxyl radicals are effective in oxidation, decomposition of protein and sugar, and reduction of the chlorophyll content. The reaction of the hydroxyl radical solution is to kill Nitzschia closterium minutissima, at the same time, to undermine vivo biological molecules so that it can not be regenerated, which can meet the requirements of the ballast water discharge of biomass.