A sonication-filterable method for acquisition of integrated bacterial communities from phycosphere

Bacteria in phycosphere interacted tightly with host microalgae by exchanging organic and inorganic matter, thus playing central roles in mediating the biogeochemical cycling of microalgae-derived organic matter. Nevertheless, due to these interdependent relationships, investigating the primary roles of bacteria in phycosphere has been a big challenge for decades, due to the lack of adequate technology methods for separation of tightly associated bacterial cells from microalgal cells. This study investigated the potentials of several methods including centrifugation, filtration, sonication with filtration, and tween lysis with sonication and filtration to determine the most efficient technology for the isolation of bacterial communities from phycosphere of dinoflagellate strains. By comparing compositions of bacterial communities using 16S rRNA gene high through-put sequencing, this study demonstrated that the sonication-filtration method has the highest bacterial cell isolation capacity and preserve the original characteristics of the bacterial communities. This study provided a crucial innovative solution for collecting bacterial communities from phycosphere for microbial bioassay.