The New Zealand Greenshell™ mussel (Perna canaliculus) is an endemic bivalve species with cultural importance, that is harvested recreationally and commercially. However, production is currently ...hampered by increasing incidences of summer mortality in farmed and wild populations. While the causative factors for these mortality events are still unknown, it is believed that increasing seawater temperatures and pathogen loads are potentially at play. To improve our understanding of these processes, challenge experiments were conducted to investigate the combined effects of increased seawater temperature and Vibrio infection on the immune and metabolic responses of adult mussels. Biomarkers that measure the physiological response of mussels to multiple-stressors can be utilised to study resilience in a changing environment, and support efforts to strengthen biosecurity management. Mussels acclimated to two temperatures (16 °C and 24 °C) were injected with either autoclaved, filtered seawater (control) or Vibriosp. DO1 (infected). Then, haemolymph was sampled 24 h post-injection and analysed to quantify haemocyte immune responses (via flow-cytometry), antioxidant capacity (measured electrochemically) and metabolic responses (via gas chromatography-mass spectrometry) to bacterial infection. Both seawater temperature and injection type significantly influenced the immune and metabolite status of mussels. A lack of interaction effects between temperature and injection type indicated that the effects of Vibrio sp. 24 h post-infection were similar between seawater temperatures. Infected mussels had a higher proportion of dead haemocytes and lower overall haemocyte counts than uninfected controls. The proportion of haemocytes showing evidence of apoptosis was higher in mussels held at 24 °C compared with those held at 16 °C. The proportion of haemocytes producing reactive oxygen species did not differ between temperatures or injection treatments. Mussels held at 24 °C exhibited elevated levels of metabolites linked to the glycolysis pathway to support energy production. The saccharopin-lysine pathway metabolites were also increased in these mussels, indicating the role of lysine metabolism. A decrease in metabolic activity (decreases in BCAAs, GABA, urea cycle metabolites, oxidative stress metabolites) was largely seen in mussels injected with Vibrio sp. Itaconate increased as seen in previous studies, suggesting that antimicrobial activity may have been activated in infected mussels. This study highlights the complex nature of immune and metabolic responses in mussels exposed to multiple stressors and gives an insight into Vibrio sp. infection mechanisms at different seawater temperatures.
•24 h post-infection, Vibrio sp. Proliferated in mussel haemolymph at 16 and 24 °C.•Haemocyte immune responses were altered by infection and temperature.•Acclimating mussels to 24 °C did not exacerbate the impact of Vibrio sp. infection.•Mussels held at 24 °C activated additional energy production pathways.•Mussels injected with Vibrio sp. showed decreased metabolic activity.
This study investigated the effect of immobilized biosurfactant-producing bacteria on the bioremediation of diesel oil-contaminated seawater. Initially, a biosurfactant-producing bacterium, LQ2, was ...isolated from a marine cold-seep region, and identified as Vibrio sp. The biosurfactant produced by LQ2 was characterized as a phospholipid, exhibiting high surface activity with strong stability. Meanwhile, the inoculation of biochar-immobilized LQ2 demonstrated superior efficiency in removing diesel oil (94.7%, reduction from 169.2 mg to 8.91 mg) over a seven-day period compared to free-cell culture (54.4%), through both biodegradation and adsorption. In addition, the microbial growth and activity were greatly enhanced with the addition of immobilized LQ2. Further experiment showed that degradation-related genes, alkB and CYP450–1, were 3.8 and 15.2 times higher in the immobilized LQ2 treatment, respectively, than those in the free cell treatment. The findings obtained in this study suggest the feasibility of applying immobilized biosurfactant-producing bacteria, namely LQ2, in treating diesel oil-contaminated seawater.
Display omitted
•A BS-producing bacteria Vibrio sp. LQ2 was isolated from cold seep region.•The produced BS exhibited good surface activity and stability.•LQ2-immobilized biochar could efficiently remediate the diesel-polluted seawater.•The microbial activity was enhanced by the addition of immobilized LQ2.•The degrading population was enriched in IB treatment as revealed by RT-qPCR.
Bacterial infections from various organisms including Vibrio sp. pose a serious hazard to humans in many forms from clinical infection to affecting the yield of agriculture and aquaculture via ...infection of livestock. Vibrio sp. is one of the main foodborne pathogens causing human infection and is also a common cause of losses in the aquaculture industry. Prophylactic and therapeutic usage of antibiotics has become the mainstay of managing this problem, however, this in turn led to the emergence of multidrug resistant strains of bacteria in the environment; which has raised awareness of the critical need for alternative non-antibiotic based methods of preventing and treating bacterial infections. Bacteriophages - viruses that infect and result in the death of bacteria - are currently of great interest as a highly viable alternative to antibiotics. This article provides an insight into bacteriophage application in controlling Vibrio species as well underlining the advantages and drawbacks of phage therapy.
Melanization of shrimp gills is a general symptom in shrimp black bill diseases (sBG); therefore, the cause is not immediately apparent. This study aimed to determine the primary and secondary agents ...associated with a black gill outbreak in the Delvar complex in the Bushehr Province of Iran. During July and August of 2020, 450 healthy and affected shrimps were collected based on brown to black gill color from three farms of the Bushehr Province in Iran. Characterization of pathogens was performed by gross signs, wet mounts, microbiological tests, histopathology methods, and sequencing of molecular markers. The mean weight and length of infected shrimps was significantly (P < 0.05) lower than the healthy shrimps. The histological examination of sBG indicated the adhesion of secondary lamellae, accumulation of hemocyte cells at the end of the secondary lamellae, and necrosis of epithelial cells with pyknosis and karyorrhexis. According to our results, Aspergillus sydowii as a primary agent correlates with sBG disease in Litopenaeus vannamei from Iran, and other biotic factors, including bacterial (Vibrio owensii and V. parahaemolyticus) probably are secondary agents associated with sBG disease.
White feces disease (WFD) recently appeared in white shrimp (Penaeus vannamei) production. Researchers conducted several studies to analyze the differences in gut microbiota between healthy and ...diseased shrimp, especially in the case of WFD. This study was conducted to compare the diversity and relative abundance of intestinal microbial communities and rearing water, histopathology of intestinal organs, and performance of shrimp production in the emergence of WFD. The gut microbiota and rearing water of white shrimp were investigated by high-throughput/next-generation sequencing. Sequencing preparation included extraction of intestinal genomic DNA and water samples, PCR amplification, quantification and mixing of PCR products, PCR product purification, and library preparation. Observational variables included bioinformatics analysis, intestinal histopathology, feed conversion ratio (FCR), and survival rate (SR). Results showed that the shrimp and rearing water samples during the WFD outbreak exhibited changes in the bacterial community structure. An increase in the abundance of pathogenic bacteria occurred, especially Vibrio sp., in shrimp intestine and rearing water during the WFD outbreak. The dominance of the genus Rubritalea in the WFD-infected shrimp intestine sample was believed to be a trigger for the decreased bacterial diversity in the shrimp intestine. The diversity and relative abundance of bacteria were higher in the intestines of normal shrimp than in those infected with WFD. The WFD-infected shrimp intestine also demonstrated intestinal tissue damage compared with normal shrimp intestine tissue. Regarding production performance at the end of maintenance, the SR and FCR values in WFD-infected ponds were lower than those in normal ponds.
•This study gives information on the bacterial diversity in the gut and rearing water of shrimp farms when the WFD outbreak.•Shrimp WFD reduces the diversity of bacterial communities in the digestive tract and rearing water.•Vibrio dominated in the digestive tracts and water rearing of WFD-infected shrimp.•The genus Rubritalea in the gut of WFD-infected shrimp could be one of the triggers for the emergence of this disease.
① and ② denoted utilizing sequence of the two nitrogen source.
Display omitted
•Vibrio sp. Y1-5 exhibited efficient nitrate and ammonium removal in the single aerobic heterotrophic ...condition.•Nitrogen removal was assimilatory nitrate reduction and ammonium assimilation.•Neither N lost nor greenhouse gas NxO producted in the process.•The strain could tolerate 1600mg/L ammonium with 844.6mg/L ammonium removal.•As a common pathogenic genus, Vibrio sp. Y1-5 was safe in aquatic ecosystems.
An aerobic marine bacterium Vibrio sp. Y1-5 was screened to achieve efficient nitrate and ammonium removal simultaneously and fix nitrogen in cells without N loss. Approximately 98.0% of nitrate (100mg/L) was removed in 48h through assimilatory nitrate reduction and nitrate reductase was detected in the cytoplasm. Instead of nitrification, the strain assimilated ammonium directly, and it could tolerate as high as 1600mg/L ammonium concentration while removing 844.6mg/L. In addition, ammonium assimilation occurred preferentially in the medium containing nitrate and ammonium with a total nitrogen (TN) removal efficiency of 80.4%. The results of nitrogen balance and Fourier infrared spectra illustrated that the removed nitrogen was all transformed to protein or stored as organic nitrogen substances in cells and no N was lost in the process. Toxicological studies with the brine shrimp species Artemia naupliia indicated that Vibrio sp. Y1-5 can be applied in aquatic ecosystems safely.
Oligoalginate lyases catalyze the degradation of alginate polymers and oligomers into monomers, a prerequisite for biotechnological utilizing alginate. In this study, we report the cloning, ...expression and biochemical characterization of a new polysaccharide lyase (PL) family 17 oligoalginate lyase, OalV17, from the marine bacterium
sp. SY01. The recombinant OalV17 showed metal ion independent and detergent resistant properties. Furthermore, OalV17 is an exo-type enzyme that yields alginate monomers as the main product and recognizes alginate disaccharides as the minimal substrate. Site-directed mutagenesis followed by kinetic analysis indicates that the residue Arg
plays a key role in substrate specificity. Furthermore, a rapid and efficient alginate monomer-producing method was developed directly from
. These results suggest that OalV17 is a potential candidate for saccharification of alginate.
Vibriosis, caused by Vibrio harveyi and Vibrio parahaemolyticus, poses a significant threat to aquaculture, resulting in substantial economic losses. Oligosaccharides are known for their ability to ...improve gut health and prevent vibriosis in aquaculture species. This study explored the fermentative utilization of galacto-oligosaccharides (GOS), manno-oligosaccharides (MOS), and inulin by Lactiplantibacillus plantarum BIOTECH 1074. GOS and glucose were the preferred substrates for L. plantarum growth, producing high levels of lactic acid, propanoic acid, and acetic acid. These compounds showed substantial anti-Vibrio activities, having inhibitory concentration values of 0.252 ± 0.005 and 0.656 ± 0.015 mg total organic acid/mL against V. harveyi, V. cholerae, and V. parahaemolyticus from GOS fermented supernatant. The fermentative capabilities of L. plantarum BIOTECH 1074, in utilizing specific oligosaccharide substrates to produce organic acids with anti-Vibrio potential, offers a promising strategy for enhancing disease management and overall efficiency in aquaculture systems.
Display omitted
•L. plantarum BIOTECH 1074 efficiently utilizes GOS for optimal growth•GOS fermentation produces beneficial short-chain fatty acids, including lactic acid•Propanoic, acetic, and lactic acids from GOS show potent anti-Vibrio activity•L. plantarum GOS fermentation offers solution for mitigating vibriosis in aquaculture
PDF
