Hub metabolites promote the bioflocculants' production in a biomass-degrading bacterium Pseudomonas boreopolis GO2.

Introduction: The low yield of bioflocculants has been a bottleneck problem that limits their industrial applications. Understanding the metabolic mechanism of bacteria that produce bioflocculants, could provide valuable insights and strategies to directly regulate their yield in future.

Methods: To investigate the change of metabolites in the process of bioflocculant production by a biomass-degrading bacterium, Pseudomonas boreopolis GO2, an untargeted metabolome analysis was performed.

Studies on immunological characteristics and transcriptomic analysis of Litopenaeus vannamei low salt-tolerance family.

Litopenaeus vannamei is a widely distributed euryhaline aquatic animal, affected by low salinity, which can impact its disease resistance and immunity. However, there is a limited understanding of the adaptation mechanisms of L. vannamei with different genetic backgrounds to low salinity.

Two colistin resistance-producing strains, isolated from coastal waters in Zhejiang, China: characteristics, multi-drug resistance and pathogenicity.

Introduction: spp. are ubiquitous inhabitants of ecosystems, and many species are opportunistically pathogenic to humans and animals. Multidrug-resistant (MDR) species have been widely detected in hospitals, urban rivers, livestock, and aquatic animals.

Zebrafish nos2a benefits bacterial proliferation via suppressing ROS and inducing NO production to impair the expressions of inflammatory cytokines and antibacterial genes.

The enzyme nitric oxide synthase 2 or inducible NOS (NOS2), reactive oxygen species (ROS) and nitric oxide (NO) are important participants in various inflammatory and immune responses. However, the functional significances of the correlations among piscine NOS2, ROS and NO during pathogen infection remain unclear. In teleost, there are two nos2 genes (nos2a and nos2b).

Toxicities of polystyrene microplastics (MPs) and hexabromocyclododecane (HBCD), alone or in combination, to the hepatopancreas of the whiteleg shrimp, Litopenaeus vannamei.

The hepatopancreas is one of the largest organs playing crucial roles in metabolism and detoxification in crustacean invertebrates. Although toxicities have been increasingly documented for the two ubiquitous pollutants, hexabromocyclododecane (HBCD) and microplastics (MPs), in model animals, little is known about their impacts on the hepatopancreas of crustaceans. To fill this knowledge gap, the effects of MPs and HBCD, alone or in combination, on the hepatopancreas were evaluated in a commercially important crustacean species (the whiteleg shrimp) by histological observation as well as quantification of hepatic lesion-, metabolism-, and detoxification-related parameters.

Impacts of dietary supplementation of bamboo vinegar and charcoal powder on growth performance, intestinal morphology, and gut microflora of large-scale loach .

Although accumulating data demonstrate that dietary supplementation of bamboo vinegar and charcoal powder (BVC) can significantly strengthen the immunity and boost the growth of domestic animals, its application potency still awaits verification in commercial fish species such as the large-scale loach The impacts of 90-day dietary supplementation of 1% and 2% BVC on survival and growth performance of the loach, and on the intestinal morphological characteristics and gut microflora were analyzed. Our data show that the large-scale loach supplied with BVC at the experimental doses had significant higher survival rates and better growth performance (indicated by greater weight gain (1.13-1.

Microplastics and bisphenol A hamper gonadal development of whiteleg shrimp (Litopenaeus vannamei) by interfering with metabolism and disrupting hormone regulation.

Gonadal development is a prerequisite for the reproductive success of an organism, and might be affected by environmental factors such as emergent pollutants. Although marine crustaceans are threatened by ubiquitous emergent pollutants such as microplastics (MPs) and bisphenol A (BPA) under realistic scenarios, studies about the impacts of these pollutants on the gonadal development of crustacean species are rare. In this study, the effects of MPs and BPA, alone or in combination, on gonadal development were investigated in whiteleg shrimp (Litopenaeus vannamei).

A real-time LAMP-based dual-sample microfluidic chip for rapid and simultaneous detection of multiple waterborne pathogenic bacteria from coastal waters.

Waterborne pathogens are becoming a serious worldwide health hazard; thus, the regular monitoring of epidemic pathogens is urgently required for public safety. In the present study, we developed a microfluidic chip integrated loop-mediated isothermal amplification technique (on-chip LAMP) to simultaneously detect 10 waterborne pathogenic bacteria, Campylobacter jejuni, Listeria monocytogenes, Salmonella enterica, Shigella flexneri, Staphylococcus aureus, Vibrio alginolyticus, V. cholerae, V.

Cloning, characterization, and transcriptional activity of β-actin promoter of African catfish (Clarias gariepinus).

Selection of suitable promoters is crucial for the efficient expression of exogenous genes in transgenic animals. Although one of the most effective promoters, the β-actin promoter, has been widely studied in fish species, it still remains unknown in the economical important African catfish (Clarias gariepinus). In this study, the β-actin promoter of African catfish (cgβ-actinP) was cloned and characterized.

A novel antiviral coumarin derivative as a potential agent against WSSV infection in shrimp seedling culture.

White spot syndrome virus (WSSV), a double-stranded DNA virus that infects crustaceans, is the most serious viral pathogen affecting shrimp farming worldwide. To reduce the economic losses caused by WSSV, we screened a novel coumarin derivative from a small molecule drug library, N-(4-((4-(((2-oxo-2H-chromen-7-yl)oxy)methyl)-1H-1,2,3-triazol-1-yl)sulfonyl)phenyl)acetamide (N2905), to evaluate its anti-WSSV effects in vivo. We determined that compound N2905, up to a concentration of 20 mg/L, significantly decreased the number of WSSV copies in Litopenaeus vannamei post-larvae, with a maximum inhibitory rate of > 90 %, and increased the survival rate of WSSV-infected post-larvae.

Simultaneous detection of multiple bacterial and viral aquatic pathogens using a fluorogenic loop-mediated isothermal amplification-based dual-sample microfluidic chip.

Rapid and user-friendly diagnostic tests are necessary for early diagnosis and immediate detection of diseases, particularly for on-site screening of pathogenic microorganisms in aquaculture. In this study, we developed a dual-sample microfluidic chip integrated with a real-time fluorogenic loop-mediated isothermal amplification assay (dual-sample on-chip LAMP) to simultaneously detect 10 pathogenic microorganisms, that is Aeromonas hydrophila, Edwardsiella tarda, Vibrio harveyi, V. alginolyticus, V.

Comparable Ecological Processes Govern the Temporal Succession of Gut Bacteria and Microeukaryotes as Shrimp Aged.

Understanding the rules that govern the successions of gut microbiota is prerequisite for testing general ecological theories and sustaining a desirable microbiota. However, the ignorance of microeukaryotes raises the question of whether gut microeukaryotes are assembled according to the same rules as bacteria. We tracked the shrimp gut bacterial and microeukaryotic communities by a longitudinal dense sampling.

Bacterial Community Dynamics During Nursery Rearing of Pacific White Shrimp () Revealed via High-Throughput Sequencing.

A 20-day trial was conducted to reveal bacterial community dynamics in a commercial nursery of larval larvae. The bacterial communities in the ambient water were profiled by high-throughput sequencing of the V4-V5 hypervariable region of the 16S rRNA gene. The results indicated that the dominant bacterial phyla between the metamorphosis stage and postlarval stage were Bacteroidetes, Proteobacteria, Cyanobacteria, and Firmicutes, representing more than 80.

Exogenous Ca mitigates the toxic effects of TiO nanoparticles on phagocytosis, cell viability, and apoptosis in haemocytes of a marine bivalve mollusk, Tegillarca granosa.

Phagocytosis suppression induced by nanoparticles (NPs) exposure is increasingly reported in marine species. However, the mechanisms underlying this impact remain poorly understood. In order to improve our present understanding of the immunotoxicity of NPs, acute (96 h) TiO NP exposure and rescue trials via exogenous supply of Ca were performed in the blood clam, Tegillarca granosa.

Ageing reduces the reproductive performance of male white shrimp Litopenaeus vannamei by altering sperm intracellular Ca concentrations and interfering with sperm apoptosis.

Although the effects of age on the reproductive performance of various invertebrates, including white shrimp Litopenaeus vannamei are increasingly well documented, the mechanisms manifesting these impacts remain poorly understood. To ascertain the mechanisms of age on reproductive performance, the sperm quality, intracellular contents of Ca, insemination and hatching rates, and status of sperm apoptosis in terms of the expression of key regulatory genes were investigated in 11 and 16 month old male L. vannamei.

The synergic impacts of TiO nanoparticles and 17β-estradiol (E2) on the immune responses, E2 accumulation, and expression of immune-related genes of the blood clam, Tegillarca granosa.

The extensive use of TiO nanoparticles (nTiO) in industrial products has led to their release into the marine environment, thereby posing a potential risk to marine organisms. However, in addition to affecting marine organisms through its inherent properties, nTiO can also act as a vehicle for other toxic pollutants due to their strong adsorption ability through the "Trojan horse" effect. Due to their potential hazard, the endocrine disrupting chemicals (EDCs) such as 17β-estradiol (E2), have been considered as one of the most serious anthropogenic threats to biodiversity and ecosystem health.

Different concentrations of Edwardsiella tarda ghost vaccine induces immune responses in vivo and protects Sparus macrocephalus against a homologous challenge.

Bacterial ghosts (BGs) can be generated by the controlled expression of the PhiX174 lysis gene E in gram-negative bacteria. They are intriguing vaccine candidates since ghosts retain functional antigenic cellular determinants often lost during traditional inactivation procedures. Here we prepared Edwardsiella tarda ghost (ETG) and tested different concentrations in vaccination trials.

Laboratory simulation reveals significant impacts of ocean acidification on microbial community composition and host-pathogen interactions between the blood clam and Vibrio harveyi.

It has been suggested that climate change may promote the outbreaks of diseases in the sea through altering the host susceptibility, the pathogen virulence, and the host-pathogen interaction. However, the impacts of ocean acidification (OA) on the pathogen components of bacterial community and the host-pathogen interaction of marine bivalves are still poorly understood. Therefore, 16S rRNA high-throughput sequencing and host-pathogen interaction analysis between blood clam (Tegillarca granosa) and Vibrio harveyi were conducted in the present study to gain a better understanding of the ecological impacts of ocean acidification.

Molecular characterization of a cDNA encoding Na/K/2Cl cotransporter in the gill of mud crab (Scylla paramamosain) during the molt cycle: Implication of its function in osmoregulation.

Although iono-regulatory processes are critical for survival of crustaceans during the molt cycle, the mechanisms involved are still not clear. The Na/K/2Cl cotransporter (NKCC), a SLC12A family protein that transports Na, K and 2Cl into cells, is essential for cell ionic and osmotic regulation. To better understand the role of NKCC in the molt osmoregulation, we cloned and characterized a NKCC gene from the mud crab, Scylla paramamosain (designated as SpNKCC).

[Expression of Edwardsiella tarda luxS gene at different growth stage].

Objective: Purpose of this work was to explore the distribution of LuxS/AI-2 quorum sensing system in Edwardsiella, and analyze expression characteristics and biological function of the key gene luxS accompanying the growth of Edwardsiella.

Methods: The full-length of AI-2/LuxS of Edwardsiella tarda was cloned by PCR based on the sequence on NCBI, then characteristics and conservative structure of this protein-coding gene were analyzed using web database and bioinformatics tools. The anti-rabbits serum was prepared after this protein was purified through prokaryotic expression.

Feasibility of infrared and Raman spectroscopies for identification of juvenile black seabream (Sparus macrocephalus) intoxicated by heavy metals.

The potential application of infrared and Raman spectroscopies was explored as rapid and nondestructive tools for the identification of juvenile black seabream samples intoxicated by heavy metals (Zn, Cu, and Cd). Discrimination models were established on the basis of the infrared and Raman spectral data using three calibration methods, namely, partial least-squares discriminant analysis, least-squares support vector machines, and random forest. The combination of two spectroscopies was studied, in which three combination strategies were proposed and compared.

[Effects of three antigens extracted from Vibrio vulnificus on the immunological protection of Nibea albiflora].

Nibea albiflora was immunized by intraperitoneal injection with either Lipopolysaccharide (LPS) or outer membrane protein (OMP) extracted from Vibrio vulnificus or formalin killed Vibrio vulnificus (FKC). The influence of the three antigens on the immunological function of Nibea albiflora was determined at different time points following the injection by testing the agglutinating antibody titers of the serum, lysozyme activity of the serum, phagocytic activity of the blood and the relative survival percentage. The results showed that the three antigens have higher immunogenicity and antigenicity than the control group(injection with sterile saline).

[Structure, function and molecular design strategies of antibacterial peptide SMAP-29: a review].

Antibacterial peptides are a family of host-defense peptides most of which are gene-encoded and produced by living organisms of all types. Antibacterial peptides are small molecular proteins with broad antimicrobial spectrum against bacteria, viruses, fungi and sometimes even as anticancer peptide. SMAP-29, a cathelicidin-like peptide derived from sheep myeloid, line alpha-helical Structure, exerts a powerful broad antimicrobial activity against different pathogens including Gram-positive and Gram-negative bacteria, fungi, viruses, parasites, spirochaetes, chlamydia and antiendotoxin activity, and particular antibacterial mechanism, rapidly to permeabilize membranes of susceptible organisms.

Molecular characterization of a glutathione peroxidase gene and its expression in the selected Vibrio-resistant population of the clam Meretrix meretrix.

Glutathione peroxidase (GPx) is an important member of cellular enzymatic antioxidant system, which may be involved in pathogen defense of host. In the present study, a selenium-dependent glutathione peroxidase (MmeGPx) gene from clam Meretrix meretrix was cloned and analyzed. The MmeGPx gene was composed of two introns of 723 bp and 238 bp and an open reading frame (ORF) of 711 bp.