Patterns and drivers of Vibrio isolates phylogenetic diversity in the Beibu Gulf, China.

Members of the genus Vibrio are ubiquitous in aquatic environments and can be found either in a culturable or a viable but nonculturable (VBNC) state. Despite widespread concerns as to how to define the occurrence and dynamics of Vibrio populations by culture-independent approaches, further physiological research and relevant biotechnological developments will require the isolation and cultivation of the microbes from various environments. The present work provides data and perspectives on our understanding of culturable Vibrio community structure and diversity in the Beibu Gulf. Finally, we isolated 1,037 strains of Vibrio from 45 samples and identified 18 different species. Vibrio alginolyticus, V. cyclitrophicus, V. tasmaniensis, V. brasiliensis, and V. splendidus were the dominant species that had regional distribution characteristics. The correlation between the quantitative distribution and community structure of culturable Vibrio and environmental factors varied with the Vibrio species and geographical locations. Among them, salinity, nitrogen, and phosphorus were the main factors affecting the diversity of culturable Vibrio. These results help to fill a knowledge gap on Vibrio diversity and provide data for predicting and controlling pathogenic Vibrio outbreaks in the Beibu Gulf.

Soil fungal diversity in natural grasslands of the Tibetan Plateau: associations with plant diversity and productivity.

Previous studies have revealed inconsistent correlations between fungal diversity and plant diversity from local to global scales, and there is a lack of information about the diversity-diversity and productivity-diversity relationships for fungi in alpine regions. Here we investigated the internal relationships between soil fungal diversity, plant diversity and productivity across 60 grassland sites on the Tibetan Plateau, using Illumina sequencing of the internal transcribed spacer 2 (ITS2) region for fungal identification. Fungal alpha and beta diversities were best explained by plant alpha and beta diversities, respectively, when accounting for environmental drivers and geographic distance. The best ordinary least squares (OLS) multiple regression models, partial least squares regression (PLSR) and variation partitioning analysis (VPA) indicated that plant richness was positively correlated with fungal richness. However, no correlation between plant richness and fungal richness was evident for fungal functional guilds when analyzed individually. Plant productivity showed a weaker relationship to fungal diversity which was intercorrelated with other factors such as plant diversity, and was thus excluded as a main driver. Our study points to a predominant effect of plant diversity, along with other factors such as carbon : nitrogen (C : N) ratio, soil phosphorus and dissolved organic carbon, on soil fungal richness.