Responses of Free-Living Vibrio Community to Seasonal Environmental Variation in a Subtropical Inland Bay

Abstract

Vibrio are widely distributed in aquatic environments and strongly associated with eutrophic environments and human health through the consumption of contaminated seafood. However, the response of the Vibrio community to seasonal variation in eutrophic environments is poorly understood. In this study, we used a Vibrio-specific 16S rRNA sequencing approach to reveal the seasonal distribution pattern and diversity of the Vibrio community in the Maowei Sea, Beibu Gulf of China. The Shannon diversity of the Vibrio community was highest in the summer, while β-diversity analysis showed that Vibrio community structures were significantly different between seasons. Distance-based redundancy analysis (dbRDA) and Mantel test analysis suggested that total dissolved nitrogen (TDN), total dissolved phosphorus (TDP), dissolved inorganic nitrogen (DIN), salinity, and temperature were the key environmental factors shaping the Vibrio community structure, indicating a strong filtering effect of trophic condition on Vibrio communities. Furthermore, through random forest analysis, V. fluvialis, V. alginolyticus, V. proteolyticus, V. splendidus, and the other eight Vibrio species were more sensitive to eutrophic changes. This study revealed seasonal changes in Vibrio communities and the influence of environmental variation on Vibrio community composition, contributing to a better understanding of their potential ecological roles in a subtropical inland bay.

Disentangling the abundance and structure of Vibrio communities in a semi-enclosed Bay with mariculture (Dongshan Bay, Southern China)

“…Our research in Dongshan Bay reveals that diversity and abundance of Vibrio species usually fluctuate seasonally with an increasing abundance in summer [52] . Similar results have been reported for other Vibrio studies using either culture dependent or independent methods [7] , [21] , [39] , [47] . To better understand the role of Vibrio species in mariculture-influenced areas and to explore effects of spatial variability of environmental factors on Vibrio community abundance and structure, a comprehensive evaluation that characterizes this important bacterial group is required.…”

“…Vibrio communities in Dongshan Bay differ from those of other coastal environments, i.e. V. fluvialis, V. gigantis, V. parahaemolyticus, and V. vulnificus in the Maowei Sea, Beibu Gulf of China [7] , [6] , as well as V. parahaemolyticus , V. vulnificus and V. cholera in the German Bight of the southeastern North Sea [13] . These differences may depend on variable source communities and environmental niches resulting in different Vibrio communities being well-adapted to changes in the respective surrounding environments.…”

“…In coastal environments, for example, it still remains unclear how mariculture changes the composition and abundance of potentially pathogenic bacteria such as Vibrio species. The abundances and community composition of Vibrio populations have been reported previously along estuaries and coasts [7] , [20] , [26] , [39] , [45] , [47] , [46] , however, how environmental heterogeneity affects the Vibrio communities in marine mariculture-influenced ecosystems is little studied. Therefore, by using three different analytic methods (culturing, bacterial universal 16S rRNA and Vibrio -specific 16S RNA molecular methods), the present study aimed to analyze the influence of mariculture-induced spatial heterogeneity in environmental variables on the spatial and temporal dynamics of the genus Vibrio .…”

“…The dominance of a particular Vibrio genus seems to be site-specific, because different species dominate in other studies (e.g. Vibrio alginolyticus , V. anguillarum , V. brasiliensis , V. campbellii , V. harveyi , V. lentus, V.neptunius, and V. parahaemolyticus ) [7] , [20] , [26] , [39] , [44] , [46] , [47] . Generally, ß-diversity and dominance of Vibrio species were significantly different in areas DS1 vs. DS2, which may be caused by a greater adaptability and faster growth of these species at local, site-specific environmental selective pressure.…”

“…V. shilonii (1.95%), V. fortis (1.59%), and V. harveyi (0.0033%). During recent years, however, Vibrio -specific primers have been widely used to study the assembly of Vibrio communities, verifying the predictive power of environmental conditions such as temperature, salinity, and pH on Vibrio community structure in several coastal areas, such as the Sydney Harbor estuary [39] , the tropical North Atlantic [16] , [9] , Chinese marginal seas [25] , [26] , [31] , [46] , and Beibu Gulf [7] , [24] . Therefore, an in-depth understanding of Vibrio community composition, their main driving factors, and responses to nutrient variation is crucial to better reveal their role for functions and ecology of marine coastal ecosystems.…”