Mechanisms and Kinetic Characterization of Bacteriolysis in Deposit Feeders

项目摘要：细菌在沉积系统中起着双重作用：作为有机碎屑的矿化剂，作为原生动物和无脊椎动物的食物。细菌的生物量、产量和群落组成决定了这些角色的特征。该研究的主要目的是评估沉积物饲料摄食对沉积细菌群落的定性和定量方面的重要性。选择进行深入研究的主要动物是沉积物食性多毛类，Arencola marina。其他多毛类（Amphitrite johnstoni和Clymenella torquata）、半硬壳类（Stereobalanus canadensis和Saccoglossus kowlevskyi）、一种有壳的全硬壳类（Caudina arenata）和一种双壳软体动物（Macoma balthica）将进行种间比较研究。裂解的机制，关键是消化表面活性剂，将被确定。体外工作将检查1)影响表面活性剂和酶之间相互作用的消化动力学；2)细菌消化的速度和程度，3)温度和反应物浓度对细菌溶解的影响，4)肠道暴露时间对消化运动学的影响。将采用温度和食品质量的体内实验来检验体外研究得出的预测结果。

P.I. Plante, Craig J. Proposal #: 9504505 PROJECT ABSTRACT Bacteria serve dual roles in sedimentary systems: as mineralizers of organic detritus and as food for protozoans and invertebrates. The biomass, production, and community composition of bacteria contribute to the character of these roles. The primary objective of the research is to assess the importance of deposit-feeder ingestion to both qualitative and quantitative aspects of sedimentary bacterial communities. The principal animal selected for intensive study is the deposit-feeding polychaete, Arencola marina. Other polychaetes (Amphitrite johnstoni and Clymenella torquata), hemichordates (Stereobalanus canadensis and Saccoglossus kowlevskyi), an apodous holothuroid (Caudina arenata), and a bivalve mollusc (Macoma balthica) will be investigated for interspecific comparisons. The mechanisms of lysis, keying on digestive surfactants, will be determined. In vitro work will examine 1) the digestive kinetics which affect interactions between surfactants and enzymes; 2) the rate and extent of bacterial digestion, 3) the influence of temperature and reactant concentrations on bacteriolysis, and 4) the effect of gut exposure time on digestive kinematics. In vivo experiments with temperature and food quality will be employed to test predictions resulting from in vitro investigations..