Low recovery of bacterial community after an extreme salinization-desalinization cycle

Abstract

BackgroundUnderstanding the recovery of bacterial communities after extreme environmental disturbances offers key opportunities to investigate ecosystem resilience. However, it is not yet clear whether bacterial communities can rebound to their pre-disturbance levels. To shed light on this issue, we tracked the responses of bacterial communities during an extreme salinization-desalinization cycle.ResultsOur results showed that salinization-up process induced an ecological succession, shifting from a community dominated by Betaproteobacteria to Gammaproteobacteria. Within the desalinization-down process, taxon-specific recovery trajectories varied profoundly, with only Gammaproteobacteria returning to their initial levels, of which Alphaproteobacteria was the most prominent member. The α-diversity indices gradually increased at oligosaline environment (0.03‰ to 3‰) and subsequently decreased profoundly at hypersaline condition (10‰ to 90‰). However, the indices did not return to pre-disturbance level along the previous trajectory observed during the desalinization. Approximately half of the original OTUs were not detected during desalinization, suggesting that the seed bank may be damaged by the hypersaline environment. Moreover, Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) implied that the osmosensors’ capacity of bacterial communities was also impaired by the hypersaline condition.ConclusionsThese results suggested that the bacterial communities showed a low recovery after the extreme salinization-desalinization cycle.Electronic supplementary materialThe online version of this article (10.1186/s12866-018-1333-2) contains supplementary material, which is available to authorized users.

Bacterial community assembly driven by temporal succession rather than spatial heterogeneity in Lake Bosten: a large lake suffering from eutrophication and salinization

“…While randomness tends to dominate the initial phase of community succession, as community succession progresses, deterministic processes become more dominant ( Dini-Andreote et al, 2015 ). The adaptability of microorganisms allows community succession to occur rapidly, typically within 2 weeks for certain processes ( Hu et al, 2018 ). Therefore, from a global perspective, the community assembly mechanism may indicate that the bacterial community in Lake Bosten is in a changing and unstable state for a long time.…”

Freshwater salinisation: a research agenda for a saltier world

“…Community level FS impacts at community level have been intensively studied. However, the current literature mainly addresses community structure (e.g., species richness or composition [25,75,76]). Functional aspects related to trait diversity, food web structure, and trophic dynamics remain poorly explored.…”

“…Denitrification [69,111], methane production [112], but also dissolved organic carbon, detrital processing, and decomposition [39,68] are key aspects linked to microbial activity that need further attention. Molecular methods used to assess microbial diversity, linking it with functionality, can help to analyse these processes [76]. The few available studies on FS consequences for microorganisms have focused on community composition [113].…”

Mangrove Facies Drives Resistance and Resilience of Sediment Microbes Exposed to Anthropic Disturbance

“…Resilience should be facilitated by their high abundances, high growth rates, high dispersal rate and high diversity (Fenchel and Finlay, 2004). Recent experimental studies emphasized contrasted abilities of microbial communities to recover from a similar disturbance (salinity stress) with either both structural and functional full recovery (Berga et al, 2017), only functional recovery (De Vrieze et al, 2017) or low recovery, in the case of extreme events (Hu et al, 2018).…”