Nutrient-imbalanced conditions shift the interplay between zooplankton and gut microbiota

Abstract

Background Nutrient stoichiometry of phytoplankton frequently changes with aquatic ambient nutrient concentrations, which is mainly influenced by anthropogenic water treatment and the ecosystem dynamics. Consequently, the stoichiometry of phytoplankton can markedly alter the metabolism and growth of zooplankton. However, the effects of nutrient-imbalanced prey on the interplay between zooplankton and their gut microbiota remain unknown. Using metatranscriptome, a 16 s rRNA amplicon-based neutral community model (NCM) and experimental validation, we investigated the interactions between Daphnia magna and its gut microbiota in a nutrient-imbalanced algal diet. Results Our results showed that in nutrient-depleted water, the nutrient-enriched zooplankton gut stimulated the accumulation of microbial polyphosphate in fecal pellets under phosphorus limitation and the microbial assimilation of ammonia under nitrogen limitation. Compared with the nutrient replete group, both N and P limitation markedly promoted the gene expression of the gut microbiome for organic matter degradation but repressed that for anaerobic metabolisms. In the nutrient limited diet, the gut microbial community exhibited a higher fit to NCM (R2 = 0.624 and 0.781, for N- and P-limitation, respectively) when compared with the Control group (R2 = 0.542), suggesting increased ambient-gut exchange process favored by compensatory feeding. Further, an additional axenic grazing experiment revealed that the growth of D. magna can still benefit from gut microbiota under a nutrient-imbalanced diet. Conclusions Together, these results demonstrated that under a nutrient-imbalanced diet, the microbes not only benefit themselves by absorbing excess nutrients inside the zooplankton gut but also help zooplankton to survive during nutrient limitation.

Characterization of the Bacterial Communities in Cichorium intybus According to Cultivation and Storage Conditions

“…Therefore, using LEfSe analysis, we identified a shift in the indigenous microbiota due to storage conditions without artificial contamination ( Figure 5 ). In general, a higher absolute LDA value indicated that the species were more enriched in the group [ 46 ]. We found that Pantoea (c), Serratia (d), Pseudomonas (e; affiliated to the Pseudomonadaceae family within the Pseudomonadales order), and Stenotrophomonas (h; affiliated to the Xanthomonadaceae family within the Xanthomonadales order) at the genus level were significantly enriched in the unwashed group stored at 4 °C (LDA score ≥ 4.0; p < 0.05).…”

Community changes of gut microbes highlight their importance in the adaptation of copepods to toxic dinoflagellates

“…GMC plays an important role in the physiology performance (e.g., fitness, growth, survival, and reproduction) of zooplankton host and greatly influences the biogeochemical cycles in the ocean (Roura et al, 2017;Callens et al, 2018;Li et al, 2021). Therefore, disentangling the major factors regulating the spatiotemporal dynamics of GMC in zooplankton remains a key issue in recent studies.…”

Gross Negligence: Impacts of Microplastics and Plastic Leachates on Phytoplankton Community and Ecosystem Dynamics

“…These MP effects on the grazer's gut may have reverse effects on ocean productivity. 141,158 Overall, phytoplankton interactions with MP and PL have direct and indirect impacts on zooplankton and the higher trophic states with profound consequences for predator fitness and survival.…”

“…Thus, they form niches facilitating accelerated microbial evolution in the plastisphere through horizontal gene transfer of potentially hazardous genes such as antibiotic resistance genes . They may also constitute “future sinks” of pathogenic and/or invasive microorganisms and pollutants which potentially affect human and ecosystem health. ,− It is also important to note that ingestion of these pathogenic and pollutant-laden MP, and the potential desorption of MP pollutants under low pH conditions, e.g., in the gut of zooplankton and fish, will have devastating consequences on higher trophic levels and even humans. − …”

“…Further, active desorption of chemicals can occur in the grazer’s gut after MP ingestion due to the low pH conditions severely altering their microbiome, prey preference, and nutritional quality for the higher trophic states. These MP effects on the grazer’s gut may have reverse effects on ocean productivity. , Overall, phytoplankton interactions with MP and PL have direct and indirect impacts on zooplankton and the higher trophic states with profound consequences for predator fitness and survival.…”