ABSTRACT
Many features of the symbiosis are critically dependent on the cellular integrity of both the bacterium and the eukaryotic cell of the invertebrate host in which the endosymbiont resides. This chapter discusses a procedure for isolating intact bacteriocytes from gill tissue of the shallow-water bivalve Lucina floridana, an inhabitant of seagrass beds. The primary advantage of using isolated bacteriocytes for metabolic and biochemical studies are that the symbiotic bacteria are retained in their natural microenvironment. The chapter suggests that experimental preparations that maintain the endosymbiotic bacteria in more biologically realistic surroundings offer new opportunities for assessing their metabolic potential. After intact bacteriocytes have been isolated, a variety of experimental approaches can be taken to characterize the morphological and functional features of the cells. Techniques for preparing the isolated bacteriocytes for viewing with electron microscopy have been developed. Briefly, isolated cells to be fixed for electron microscopy are transferred to Beem capsules and centrifuged at low speed to concentrate the cells.
