Qian Liu

Second Institute of Oceanography MNR · Marine Ecosystem and Biogeochemistry

Viruses are the most abundant life forms in the sea, influencing the community structure and metabolism of host cells as well as biogeochemical cycles. However, the diversity and ecological roles of viruses within seamount ecosystems, natural microbiota havens characterized by high biodiversity, remain unknown. Here, the first seamount viral genome...

When internal solitary waves (ISW) propagate to the continental shelf, they typically runup and break on the forereef. This process might lead to periodic temperature drops at the reef slope, which has potential to protect coral reefs from bleaching threats. A series of laboratory experiments were conducted to investigate turbulence characteristics...

A gram-stain-negative, aerobic, rod-shaped bacterium strain CJK-A8-3T was isolated from a polyamine-enriched seawater sample collected from the Changjiang River estuary of China. The colonies were white and circular. Strain CJK-A8-3T grew optimally at 35 °C, pH 7.0 and 1.5% NaCl. Its polar lipids contained phosphatidylglycerol, phosphatidic acid, u...

Ammonia-oxidizing archaea (AOA) and bacteria (AOB), nitrite-oxidizing bacteria (NOB), and complete ammonia oxidizers (comammox) are responsible for nitrification in nature; however, some groups have been reported to utilize labile-dissolved organic nitrogen (LDON) for satisfying nitrogen demands. To understand the universality of their capacity of...

We used molecular biomarkers (brassicasterol, dinosterol and C37 alkenones) measured from the surface sediments of the Bering Sea, the Chukchi Sea and the western Arctic Ocean in years of 1999 and 2010 to represent the groups of phytoplankton (diatoms, dinoflagellates and coccolithophores) and reconstruct the phytoplankton composition structure and...

Thaumarchaeota are among the most abundant prokaryotes in the ocean, playing important roles in carbon and nitrogen cycling. Marine Thaumarchaeota ecotypes exhibit depth‐related diversification and seasonal changes. However, transcriptomic activities concerning niche partitioning among thaumarchaeal ecotypes remain unclear. Here, we examined the va...

Heterotrophic prokaryotes constitute the largest living biomass in the ocean and can be divided into particle-associated (PA) and free-living (FL) fractions. PA and FL prokaryotic communities play critical roles in the biogeochemical cycles of particulate and dissolved organic matter; however, their community assembly processes, biogeographical dis...

Polyamines are key components of labile dissolved organic nitrogen in coastal waters. They are found in all living organisms, which are the sources of dissolved organic matter in marine environments. The concentrations of dissolved polyamines are generally low and are controlled as much by production as by consumption. Understanding the dynamics of...

The northern slope water of the South China Sea (SCS) is oligotrophic. The regenerated nitrogen from dissolved organic nitrogen (DON) has been suggested to play a pivotal role in sustaining primary productivity; however, DON cycling has not been investigated there. Dissolved free amino acids (DFAAs) and polyamines (DFPAs) are two major groups of la...

The workshop aimed to identify coherent, collaborative, and scientifically robust solutions to addressing taxonomic knowledge gaps in various stages from collection, preservation and archiving of biological samples and taxonomic data to identification and description of species. Specifically, the workshop focused on: (i) identifying specific needs...

Bacterial communities in sediments of the Caiwei Seamount, a typical guyot located in the northwest Pacific Ocean, were investigated. A total of 727,879 16S ribosomal RNA gene sequences were retrieved from eight sediment samples of the top (mean depth = 1,407 m) and the base (mean depth = 5,525 m) of the guyot through pyrosequencing of V6 hypervari...

Dissolved organic nitrogen (DON) can account for a large fraction of the dissolved nitrogen (N) pool in the ocean, but the cycling of marine DON is poorly understood. Recent discoveries that urea‐ and cyanate‐N can be oxidized by some strains of Thaumarchaeota suggest that these abundant microbes may be able to access and oxidize a fraction of the...

The Changjiang estuary and its adjacent East China Sea (ECS) have been considered as one of the most dynamic areas significantly contributing to elemental exchanges globally. The purpose of this study was to understand the alteration of microbial consortia at the interface of riverine and coastal environments in relation to environmental variations...

A Gram-stain-negative bacterium, designated NH169-3T, was isolated from a surface seawater sample of the South China Sea and subjected to a taxonomic polyphasic investigation. Strain NH169-3T was strictly aerobic, non-motile, non-spore-forming and rod-shaped. The colony was 1.0-2.0 mm in diameter after the growth on marine agar at 30 °C for 72 h. T...

Background Type strains of the genus Porphyrobacter belonging to the family Erythrobacteraceae and the class Alphaproteobacteria have been isolated from various environments, such as swimming pools, lake water and hot springs. P. cryptus DSM 12079T and P. tepidarius DSM 10594T out of all Erythrobacteraceae type strains, are two type strains that ha...

Galectins are β-galactoside binding lectins that play crucial roles in innate immunity in vertebrates and invertebrates through their conserved carbohydrate-recognition domains (CRDs). In the present study, single- and four-CRD-containing galectins were identified in oyster Crassostrea gigas (designated CgGal-2 and CgGal-3). The open reading frames...

Mid-summer peaks in the abundance of Thaumarchaeota and nitrite concentration observed on the Georgia, USA, coast could result from in situ activity or advection of populations from another source. We collected data on the distribution of Thaumarchaeota, ammonia-oxidizing betaproteobacteria (AOB), Nitrospina, environmental variables and rates of am...

Croceicoccus marinus E4A9Twas isolated from deep-sea sediment collected from the East Pacific polymetallic nodule area. The strain is able to produce esterase, which is widely used in the food, perfume, cosmetic, chemical, agricultural and pharmaceutical industries. Here we describe the characteristics of strain E4A9, including the genome sequence...

The genus Porphyrobacter belongs to aerobic anoxygenic phototrophic bacteria cluster. Porphyrobacter neustonensis DSM 9434 was isolated from a eutrophic freshwater pond in Australia, and is able to synthesize Bacteriochlorophyll a as well as grow under aerobic conditions. It is the type species of the genus Porphyrobacter. Here we describe the char...

Altererythrobacter dongtanensis KCTC 22672T is a Gram-stain-negative, yellow-pigmented, and aerobic bacterium isolated from a tidal flat of Dongtan Wetland, Chongming Island, China. Here we describe its complete genome sequence, annotation and features. The complete genome of A. dongtanensis KCTC 22672T consists of one chromosome (3,009,495 bp) wit...

There are few measurements of nitrification in polar regions, yet geochemical evidence suggests that it is significant, and chemoautotrophy supported by nitrification has been suggested as an important contribution to prokaryotic production during the polar winter. This study reports seasonal ammonia oxidation (AO) rates, gene and transcript abunda...

Previous field observations suggest that the composition of intracellular polyamine pools in phytoplankton determines the profile of polyamines released to the surrounding environment; thus, knowing how these pools vary among species and in response to factors affecting phytoplankton growth provides a basis for understanding fluctuations of dissolv...

Polyamines are short-chain aliphatic compounds containing multiple amine groups. They are important components of the cytosol of eukaryotes and are present at mmol L−1 concentrations inside phytoplankton cells, while complex polyamines play a role in biosilica deposition. Concentrations of polyamines measured in seawater are typically in the sub-nm...

Short-chained aliphatic polyamines (PAs) are a class of labile dissolved organic nitrogen (DON) that has biogeochemical similarities to dissolved free amino acids (DFAAs). Here we investigated the relative contributions of DFAAs and PAs to the total DON pool and their diurnal dynamics at different depths at the Gray’s Reef National Marine Sanctuary...