Biology subjects

Cardazzo, B.

Publications and source records attributed to Cardazzo, B..

2 recordsLinked to original sources

bioRxiv2024

Generating gnotobiotic bivalves: a new method on Manila clam (Ruditapes philippinarum)

The microbiome, which encompasses microbial communities associated with animal hosts, exerts a profound impact on host physiology and ecosystem dynamics. The application of advanced sequencing technologies has enabled researchers to investigate the composition of microbiomes across a range of hosts and environments. While correlating microbial composition with health outcomes has been a priority, interpreting such data requires caution to avoid overemphasizing the roles of microbes. Understanding microbial influence demands mechanistic insights, which are often elucidated through gnotobiology. Despite their limitations in representing animal diversity, model organisms offer the advantage of reproducibility and experimental tractability. However, the marine realm, especially bivalves, which are crucial for ecosystem functioning and aquaculture, lacks gnotobiotic models. In this study, we present a method for generating microbiome-depleted and gnotobiotic clams (Ruditapes philippinarum), one of the most widely farmed molluscs in the world and a sentinel organism for climate change. This model expands gnotobiotic research into marine invertebrates, thereby enabling investigations into the impact of microbes on such key animal species.

microbiology↗

bioRxiv2019

Diauxie and co-utilization are not exclusive during growth in nutritionally complex environments

The classic view of microbial growth strategy when multiple carbon sources are available states that they either metabolize them sequentially (diauxic growth) or simultaneously (co-utilization). This perspective is biased by the fact that this process has been mainly analysed in over-simplified laboratory settings, i.e. using a few model microorganisms and growth media containing only two alternative compounds. Models concerning the mechanisms and the dynamics regulating nutrients assimilation strategies in conditions that are closer to the ones found in natural settings (i.e. with many alternative carbon/energy sources) are missing. Here, we show that bacterial co-utilization and sequential uptake of multiple substrates can coexist when multiple possible nutrients are provided in the same growth experiment, leading to an efficient exploitation of nutritionally complex settings. The order of nutrient uptake is determined by the actual biomass yield (and growth rate) that can be achieved when the same compounds are provided as single carbon sources. Finally, using two alternative theoretical models we show that this complex metabolic phenotype can be explained by a tight regulation process that allows microbes to actively modulate the different assimilatory pathways involved.

systems biology↗