Culture-Dependent and -Independent Analyses Reveal the Diversity, Structure, and Assembly Mechanism of Benthic Bacterial Community in the Ross Sea, Antarctica

Abstract

The benthic bacterial community in Antarctic continental shelf ecosystems are not well-documented. We collected 13 surface sediments from the Ross Sea, a biological hotspot in high-latitude maritime Antarctica undergoing rapid climate change and possible microflora shift, and aimed to study the diversity, structure and assembly mechanism of benthic bacterial community using both culture-dependent and -independent approaches. High-throughput sequencing of 16S rRNA gene amplicons revealed 370 OTUs distributed in 21 phyla and 284 genera. The bacterial community was dominated by Bacteroidetes, Gamma- and Alphaproteobacteria, and constituted by a compact, conserved and positively-correlated group of anaerobes and other competitive aerobic chemoheterotrophs. Null-model test based on βNTI and RCBray indicated that stochastic processes, including dispersal limitation and undominated fractions, were the main forces driving community assembly. On the other hand, environmental factors, mainly temperature, organic matter and chlorophyll, were significantly correlated with bacterial richness, diversity and community structure. Moreover, metabolic and physiological features of the prokaryotic taxa were mapped to evaluate the adaptive mechanisms and functional composition of the benthic bacterial community. Our study is helpful to understand the structural and functional aspects, as well as the ecological and biogeochemical role of the benthic bacterial community in the Ross Sea.

Influence of the Depth and Season on Microbial Community Dynamics of the Black Sea

“…Marine microbial communities play a fundamental role in the biogeochemical cycles of elements (Ji et al, 2019;Sonthiphand et al, 2019), food web structure, and energy ow (Li et al, 2019). Understanding the mechanism of bacterial community assembly is one of the most critical objectives of microbial ecology.…”

Uncovering fungal community composition in natural habitat of Ophiocordyceps sinensis using high-throughput sequencing and culture-dependent approaches

“…Compared with culture dependent approach which had limitations because of the selectivity of media and culture conditions, high-throughput sequencing was considered to provide better resolution of microbial community composition, but, it still showed biases. Each approach tend to capture different microbial community fractions, result in only a fraction of the taxa recovered did overlap, which also highlighting the complementarity of two approaches [ 29 , 30 ]. Therefore, it is believed that the coordination of culture-dependent and independent approaches would provide promising avenue to illuminate microbial community assembly in natural O. sinensis .…”

Novel Psychrophiles and Exopolymers from Permafrost Thaw Lake Sediments

“…At the species level, however, there are limitations due to the restricted discriminatory capacity of the 16S rRNA gene for rare taxa, thereby underestimating the full bacterial diversity. Parallel use of both procedures is desirable for obtaining complementary information about the taxonomic composition, genetic richness, and potential metabolic pathways of microbial communities [ 51 ]. On the one hand, the cultivable microbial populations represent only a minute fraction of the whole community, and are strictly limited to the growing parameters set up by the microbiologist.…”