Exopolysaccharide-producing bacteria enhanced Pb immobilization and influenced the microbiome composition in rhizosphere soil of pakchoi ( L.).

Lead (Pb) contamination of planting soils is increasingly serious, leading to harmful effects on soil microflora and food safety. Exopolysaccharides (EPSs) are carbohydrate polymers produced and secreted by microorganisms, which are efficient biosorbent materials and has been widely used in wastewater treatment to remove heavy metals. However, the effects and underlying mechanism of EPS-producing marine bacteria on soil metal immobilization, plant growth and health remain unclear.

Pan-Genomic and Transcriptomic Analyses of Marine Hao 2018 Revealed Its Genomic and Metabolic Features.

The genomic and carbohydrate metabolic features of Hao 2018 ( Hao 2018) were investigated through pan-genomic and transcriptomic analyses, and key enzyme genes that may encode the process involved in its extracellular polysaccharide synthesis were screened. The pan-genome of the strains consists of a core-genome containing 2331 genes, an accessory-genome containing 956 genes, and a unique-genome containing 1519 genes. Clusters of Orthologous Groups analyses showed that harbors strain-specifically diverse metabolisms, probably representing high evolutionary genome changes.

Effect of Different Initial Fermentation pH on Exopolysaccharides Produced by Hao 2018 and Identification of Key Genes Involved in Exopolysaccharide Synthesis via Transcriptome Analysis.

Exopolysaccharides (EPSs) are carbohydrate polymers produced and secreted by microorganisms. In a changing marine environment, EPS secretion can reduce damage from external environmental disturbances to microorganisms. Meanwhile, EPSs have promising application prospects in the fields of food, cosmetics, and pharmaceuticals.

Interactive effects of ocean acidification, ocean warming, and diurnal temperature cycling on antioxidant responses and energy budgets in two sea urchins Strongylocentrotus intermedius and Tripneustes gratilla from different latitudes.

To accurately predict the fitness of marine ectotherms under the climate change scenarios, interactive effects from multiple environmental stressors should be considered, such as ocean acidification (OA), ocean warming (OW) and diurnal temperature cycling (DTC). In this work, we evaluated and compared the antioxidant capacity and metabolism homeostasis of two sea urchins, viz. the temperate species Strongylocentrotus intermedius and the tropical species Tripneustes gratilla, in response to oceanic conditions under a climate change scenario.

Exacerbation of copper pollution toxicity from ocean acidification: A comparative analysis of two bivalve species with distinct sensitivities.

In estuarine ecosystems, bivalves experience large pH fluctuations caused by the anthropogenic elevation of atmospheric CO and Cu pollution. This study investigates whether Cu toxicity increases indiscriminately in two bivalve species from different estuarine habitats as a result of elevated Cu bioaccumulation in acidified seawater. This was carried out by evaluating the effects of Cu exposure on two bivalve species (clams and scallops) for 28 d, at a series of gradient pH levels (pH 8.

Isolation, Optimization of Fermentation Conditions, and Characterization of an Exopolysaccharide from Hao 2018.

In recent years, the wide application of exopolysaccharides (EPSs) in food, cosmetics, medicine, and other fields has drawn tremendous attention. In this study, an EPS produced by Hao 2018 was isolated and purified, and its fermentation conditions were optimized. Its structure and biological functions were also studied.

A bactericidal permeability-increasing protein (BPI) from manila clam Ruditapes philippinarum: Investigation on the antibacterial activities and antibacterial action mode.

Bactericidal permeability-increasing protein (BPI) is an antimicrobial protein with potent endotoxin-neutralising activity and plays a crucial role in innate immunity against bacterial infection. In the present study, a bpi (designed as rpbpi) was identified and characterized from manila clam Ruditapes philippinarum. Multiple alignments and phylogenetic analysis suggested that rpbpi was a new member of the bpis family.

A macin identified from Venerupis philippinarum: Investigation on antibacterial activities and action mode.

In the present study, a macin was cloned and characterized from clam Venerupis philippinarum (designed as VpMacin). The full-length cDNA of VpMacin was of 579 bp, encoding a peptide of 87 amino acids with the predicted molecular weight of 9.7 kDa.

Molecular cloning and characterization of FADD from the manila clam Ruditapes philippinarum.

Fas-associated protein with death domain (FADD) is an essential element in cell death, and also implicates in cell cycle progression, inflammation and innate immunity. In the study, an FADD (designated as RpFADD) was identified and characterized from manila clam, Ruditapes philippinarum. Multiple alignments and phylogenetic analysis strongly suggested that RpFADD was a new member of the FADD family.

A peptidoglycan recognition protein involved in immune recognition and immune defenses in Ruditapes philippinarum.

Peptidoglycan recognition proteins (PGRPs) are important pattern recognition receptors in the innate immune system of invertebrates. In the study, a short PGRP (designed as RpPGRP) was identified and characterized from the manila clam Ruditapes philippinarum. The open reading frame of RpPGRP encoded a polypeptide of 249-amino acids with a calculated molecular mass of 27.

Seawater acidification increases copper toxicity: A multi-biomarker approach with a key marine invertebrate, the Pacific Oyster Crassostrea gigas.

Ocean acidification (OA) has been found to increase the release of free Cu in seawater. However, only a handful of studies have investigated the influence of OA on Cu accumulation and cellular toxicity in bivalve species. In this study, Pacific oysters, Crassostrea gigas, were exposed to 25 μg/L Cu at three pH levels (8.

Scavenger receptor class B type I (SR-BI) in Ruditapes philippinarum: A versatile receptor with multiple functions.

In the present study, a scavenger receptor class B type I (designed as RpSR-BI) was cloned and characterized from manila clam Ruditapes philippinarum. The full-length cDNA of RpSR-BI was of 2000 bp, containing an open reading frame (ORF) of 1515 bp. Multiple alignments and phylogenetic analysis strongly suggested that RpSR-BI was a member of the scavenger receptors family.

Microplastic in cultured oysters from different coastal areas of China.

Microplastics are an emerging concern in the marine environment due to their small size; they can be ingested by aquatic organisms, especially filter-feeding organisms, such as oysters. The presence of microplastics in seafood may pose a threat to food safety, and there is an urgent need to evaluate the potential risks of microplastics to human health. This study quantified the microplastics in oysters from 17 sites along the coastline of China.

Integrative Biomarker Assessment of the Influence of Saxitoxin on Marine Bivalves: A Comparative Study of the Two Bivalve Species Oysters, , and Scallops, .

Harmful algae blooms have expanded greatly in recent decades, and their secreted toxins pose a severe threat to human health and marine ecosystems. Saxitoxin (STX) is a main paralytic shellfish poison naturally produced by marine microalgae of the genus . Despite numerous studies have assessed the impacts of STX on marine bivalves, comparative study on the toxicity of STX on bivalves with distinct accumulation ability (such as oysters and scallops) has been seldom investigated.

The impact of ocean acidification and cadmium on the immune responses of Pacific oyster, Crassostrea gigas.

Seawater acidification (OA) and cadmium (Cd) has the potential to lead to immunosuppression effect on marine bivalves. However, the interaction between these two environmental stressors on immune system of marine bivalves has received limited attention. In order to evaluate the defense responses of oysters under the combined exposure to OA and cadmium, the oysters Crassostrea gigas were exposed to 10 μg/L Cd at three pH levels (8.

Seawater Acidification Reduced the Resistance of to Challenge: An Energy Metabolism Perspective.

Negative physiological impacts induced by exposure to acidified seawater might sensitize marine organisms to future environmental stressors, such as disease outbreak. The goal of this study was to evaluate if ocean acidification (OA) could reduce the resistance capability of the Pacific oyster () to challenge from an energy metabolism perspective. In this study, the Pacific oyster was exposed to OA (pH 7.

CO-induced ocean acidification impairs the immune function of the Pacific oyster against Vibrio splendidus challenge: An integrated study from a cellular and proteomic perspective.

Ocean acidification (OA) and pathogenic diseases pose a considerable threat to key species of marine ecosystem. However, few studies have investigated the combined impact of reduced seawater pH and pathogen challenge on the immune responses of marine invertebrates. In this study, Pacific oysters, Crassostrea gigas, were exposed to OA (~2000 ppm) for 28 days and then challenged with Vibrio splendidus for another 72 h.

Seawater acidification aggravated cadmium toxicity in the oyster Crassostrea gigas: Metal bioaccumulation, subcellular distribution and multiple physiological responses.

Mounting evidence has demonstrated the combined effects of ocean acidification (OA) and other environmental stressors on marine organisms. Although metal pollution is widely distributed in coasts and estuaries, the combined effects of OA and metal pollution have received little attention until recent years. In this study, the accumulation and subcellular distribution of cadmium (Cd) and the physiological responses of the oyster Crassostrea gigas were investigated after 31 days of exposure to OA and Cd, either alone or in combination.

Microplastic pollution in sediments from the Bohai Sea and the Yellow Sea, China.

Microplastics are one of the most significant pollutants in the marine environment and accumulate in sediments all over the world. To assess the pollution level in the marine environment in China, the distribution and abundance of microplastics in sediments from the Bohai Sea and the Yellow Sea were investigated in this study. The sediment samples were collected from 72 different sites in the Bohai Sea and the Yellow Sea.

Individual and Combined Toxicities of Benzo[a]pyrene and 2,2',4,4'-Tetrabromodiphenyl Ether on Early Life Stages of the Pacific Oyster, Crassostrea gigas.

Persistent organic pollutants (POPs) are ubiquitous and coexisted in the aquatic environment. Individual and combined toxic effects of benzo[a]pyrene (BaP) and 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) on embryogenesis, and larval survival of the Pacific oyster were investigated. The EC values of BaP, BDE-47 and their mixture on embryogenesis were 18.

Molecular characterization and antibacterial activity of a phage-type lysozyme from the Manila clam, Ruditapes philippinarum.

A phage-type lysozyme, designed as RpPLYZ, was cloned and characterized from the clam Ruditapes philippinarum. The full-length cDNA of RpPLYZ was of 699 bp with an open reading frame (ORF) of 534 bp, encoding a polypeptide of 177-amino acid with a calculated molecular mass of 19.6 kDa and an isoelectric point of 9.

Molecular characterization, expression and antimicrobial activities of two c-type lysozymes from manila clam Venerupis philippinarum.

Lysozymes play an important role in the innate immune responses with which mollusks respond to bacterial invasion through its lytic activity. In the present study, two c-type lysozymes (designed as VpCLYZ-1 and VpCLYZ-2, respectively) were identified and characterized from the manila clam Venerupis philippinarum. The full-length cDNA of VpCLYZ-1 and VpCLYZ-2 was of 629 and 736 bp, encoding a polypeptide of 156 and153 amino acid residues, respectively.

An integrative biomarker approach to assess the environmental stress in the north coast of Shandong Peninsula using native oysters, Crassostrea gigas.

An integrative biomarker approach was employed to evaluate the environmental quality of the north coast of Shandong Peninsula along the southern Bohai Sea of China, where pollution is an imminent threat due to rapid urbanization and industrialization. A battery of biomarkers and the metal bioaccumulation in tissues of native oyster Crassostrea gigas were measured under field conditions. Integrative biomarker index (IBR) and metal body burden were calculated to differentiate the pollution status of seven sampling sites.

Effects of ocean acidification on immune responses of the Pacific oyster Crassostrea gigas.

Ocean acidification (OA), caused by anthropogenic CO2emissions, has been proposed as one of the greatest threats in marine ecosystems. A growing body of evidence shows that ocean acidification can impact development, survival, growth and physiology of marine calcifiers. In this study, the immune responses of the Pacific oyster Crassostrea gigas were investigated after elevated pCO2 exposure for 28 days.