潮间带滩涂颗粒有机碎屑生物组成及其游离氨基酸分析

Biological composition and FAA content of particulate organic detritus from mudflat of intertidal zone

福建省福宁湾潮间带滩涂表层粉砂质粘土海泥中含有丰富的颗粒有机碎屑和粉砂颗粒。有机碎屑颗粒大小悬殊,其长径5.3～95.0μm,平均46.08±27.52μm。粉砂颗粒粒径4.0～37.0μm,平均17.18±9.63μm。具有生物群落的颗粒有机碎屑包含拟铃虫(细弱拟铃虫、圆钝拟铃虫、肿状拟铃虫、百乐拟铃虫和妥肯丁拟铃虫)、底栖硅藻(圆筛藻、斜纹藻、布纹藻、舟形藻、斑条藻、卵形藻、菱形藻和筒柱藻)和细菌(微球菌密度7.728×109个细胞/g～13.136×109个细胞/g),偶见许水蚤卵粒和海洋线虫。应用柱前衍生高效液相色谱法测定了颗粒有机碎屑的游离氨基酸含量,其总量为385.3～569.7μmol/kg,平均473.24±62.40μmol/kg。15种游离氨基酸中以甘氨酸、脯氨酸、丝氨酸、赖氨酸、谷氨酸和丙氨酸含量较高,其百分组成分别为16.41%、15.95%、13.32%、7.29%、6.96%和6.91%。研究结果表明,在潮间带滩涂形成了颗粒有机碎屑、细菌(微球菌)、微型硅藻、原生动物(拟铃虫)和大弹涂鱼的食物链营养关系。

Surface silt clay of intertidal mudflat in Fulin Bay of Fujian province contains plenty of particulate organic detritus and silt grain. The sizes of the particulate organic detritus vary greatly, from 5.3 μm to 95.0 μm in length, with the average 46.08±27.52 μm. The sizes of the silt grain vary from 4.0 μm to 37.0 μm,with the average 17.18±9.63 μm. The particulate organic detritus is a biological community which contains Tintinnopsis（T. gracilis, T. rotundata, T. turgita, T. beroidea and T. tocantinensis）, benthonic diatoms （Coscinodiscus, Pleurosigma , Gyrosigma , Navicula , Grammatophora , Cocconeis , Nitzschia and Cylindrotheca ）and bacteria（Micrococcus, 7. 728× 10^9 cells/g- 13. 136 × 10^9 cells/g）. Occasionally, eggs of Schmackeria and the marine nematode can also be found in particulatc organic detritus. Free a- mino acids（FAA）content in particulate organic detritus were determined by using high performance liquid chromatography with pre-column derivation. The total content of FAA varied from 385.3 μmol/kg to 569.7 μmol/kg,with the average 473.24±62.40 μmol/kg. Among 15 FAA tested, the levels of glycine, proline, serine, lysine, glutamic acid and alanine were relatively high, with the corresponding percentages being 16.41%, 15.95%, 13.32%, 7.29%, 6.96% and 6.91%, respectively. The results showed that a food chain formed in the intertidal mudflat, which was composed of particulate organic detritus, bacteria（Micrococcus）, micro-diatoms, protozoa（Tintinnopsis） and the mudskipper（Boleophthalmus pectinirostris ）.