Uptake Of Amino Acids By The Nemertean, Procephalothrix Simulus Iwata

The nemertean Procephalothrix simulus Iwata, 1952, which is one of most common intertidal nemerteans in Qingdao and vicinity, is selected as experimental animal. Experiment results illustrate that Procephalothrix simulus is capable of uptake of amino acids from environment. The main results of the study are as follows:1. Using stable isotope mass spectrograph to determineδ13C value of before and after nemertean uptake of 13C-amino acids, data provide evidence that nemertean, Procephalothrix simulus is capable of uptake of amino acids (alanine and glycine) from artificial seawater. Absorption of alanine after 4h, 8h and 12h are 8.57±0.21μg,16.65±3.46μg and 38.74±3.07μg respectively. Absorption of glycine after 4h, 8h and 12h are 11.25±0.58μg,21.88±0.24μg and 48.45±3.64μg respectively. Influx and net flux of amino acids into the nemertean were examined. Influx of alanine and glycine were determined using 13C labeled substrates and monitoring the increase ofδ13C value in the nemertean body. Net flux of alanine and glycine from artifical seawater were determined by high-performance liquid chromatography (HPLC). Rate of influx and net flux were compared. Rate of maximum influx (Jmax) and ambient substrate concentration at which influx is half-maximal (Kt) are reported. The Kt for alanine and glycine is 4.86μM and 6.05μM, respectively. The Jmax for alanine and glycine is 1.83μmol/g.h and 3.01μmol/g.h.2. The absorption of 16 amino acids from artificial seawater by Procephalothrix simulus is investigated using high-performance liquid chromatography (HPLC). We study how temperature effect on the amino acids uptake. At four temperatures (12°C, 20°C, 28°C, 32°C), Procephalothrix simulus is able to absorb 15 kinds of amino acids. But glutamic acid (Glu) was not absorbed markedly like other amino acids. The more the temperature rised, the more the amino acids absorbed. But at 32°C, the absorption of amino acids reduced. And rate of uptake at warmer temperature (28°C and 32°C) is faster than at colder temperature (12°C and 20°C).3. The absorption of 16 amino acids from artificial seawater by Procephalothrix...