A combined toxicological impact on Artemia salina caused by the presence of dust particles, microplastics from cosmetics, and paracetamol.

Environmental pollution poses a significant and pressing threat to the overall well-being of aquatic ecosystems in modern society. This study showed that pollutants like dusts from AC filter, fan wings and Traffic dust PM 2.5 were exposed to Artemia salina in pristine form and in combination. The findings indicated that exposure to multi-pollutants had a detrimental effect on the hatching rates of A. salina cysts. Compared to untreated A. salina, the morphology of adult (7th day old) A. salina changed noticeably after each incubation period (24-120 h). Oxidative stress increased considerably as the exposure duration increased from 24 to 120 h compared to the control group. There was a time-dependent decline in antioxidant enzyme activity and total protein concentration. When all particles were used all together, the total protein content in A. salina decreased significantly. All particles showed a considerable decline in survival rate. Those exposed to traffic dust particles showed significantly higher levels of oxidative stress and antioxidant activity than those exposed to other particles.

ArHsp90 is important in stress tolerance and embryo development of the brine shrimp, Artemia franciscana.

Females of the extremophile crustacean, Artemia franciscana, either release motile nauplii via the ovoviviparous pathway or encysted embryos (cysts) via the oviparous pathway. Cysts contain an abundant amount of the ATP-independent small heat shock protein that contributes to stress tolerance and embryo development, however, little is known of the role of ATP-dependent molecular chaperone, heat shock protein 90 (Hsp90) in the two processes. In this study, a hsp90 was cloned from A. franciscana. Characteristic domains of ArHsp90 were simulated from the deduced amino acid sequence, and 3D structures of ArHsp90 and Hsp90s of organisms from different groups were aligned. RNA interference was then employed to characterize ArHsp90 in A. franciscana nauplii and cysts. The partial knockdown of ArHsp90 slowed the development of nauplius-destined, but not cyst-destined embryos. ArHsp90 knockdown also reduced the survival and stress tolerance of nauplii newly released from A. franciscana females. Although the reduction of ArHsp90 had no effect on the development of diapause-destined embryos, the resulting cysts displayed reduced tolerance to desiccation and low temperature, two stresses normally encountered by A. franciscana in its natural environment. The results reveal that Hsp90 contributes to the development, growth, and stress tolerance of A. franciscana, an organism of practical importance as a feed source in aquaculture.

Chromosome-Level Assembly of Artemia franciscana Sheds Light on Sex Chromosome Differentiation.

Since the commercialization of brine shrimp (genus Artemia) in the 1950s, this lineage, and in particular the model species Artemia franciscana, has been the subject of extensive research. However, our understanding of the genetic mechanisms underlying various aspects of their reproductive biology, including sex determination, is still lacking. This is partly due to the scarcity of genomic resources for Artemia species and crustaceans in general. Here, we present a chromosome-level genome assembly of A. franciscana (Kellogg 1906), from the Great Salt Lake, United States. The genome is 1 GB, and the majority of the genome (81%) is scaffolded into 21 linkage groups using a previously published high-density linkage map. We performed coverage and FST analyses using male and female genomic and transcriptomic reads to quantify the extent of differentiation between the Z and W chromosomes. Additionally, we quantified the expression levels in male and female heads and gonads and found further evidence for dosage compensation in this species.

Comparación de las propiedades antioxidantes y contenido de polifenoles de extractos acuosos de las algas marinas Bryothamnion triquetrum y Halimeda opuntia / Comparation of antioxidants properties and polyphenols content of aqueous extract from seaweeds Bryothamnion triquetrum and Halimeda opuntia

Objetivos. Evaluar y comparar las propiedades antioxidantes mediante ensayos in vitro de extractos acuosos de las algas roja Bryothamnion triquetrum y verde Halimeda opuntia y su relación con el contenido de polifenoles. Material y Métodos. Se utilizaron las técnicas in vitro: DPPH, Capacidad reductora, Inhibición de la peroxidación lipídica e inhibición de la hemólisis inducida por AAPH. Resultados. B. triquetrum: DPPH; CI50=1,15 ± 0,06, capacidad reductora a concentración; 128 mg/mL, DO=2,798, inhibición de la peroxidación lipídica; CI50=5,09± 0,25 e inhibición de la hemólisis con 12 mg/ mL; 35 %. H. opuntia: DPPH; CI50=12,34 ± 0,30 mg/mL, capacidad reductora; DO=0,800, inhibición de la peroxidación lipídica; CI50=1,25± 0,31 mg/mL e inhibición de la hemólisis; 82%. Conclusiones. Los resultados evidencian que B triquetrum resulto mucho más eficiente en los ensayos de DPPH y Capacidad reductora mientras H opuntia resulta más eficiente en Inhibición de la peroxidación lipídica e inhibición de la hemólisis. Se discuten algunos aspectos acerca de sus posibles mecanismos de acción

Objective. To evaluate and compare the antioxidant activity displayed by seaweed H. opuntia and B. triquetrum using different experimental in vitro antioxidant assessment models. Material and Methods. The following techniques are utilized: DPPH, Reducing power, inhibition of lipid peroxidation and inhibition of haemolysis. Results. B. triquetrum: DPPH; IC =1.15 ± 0.06, Reducing power (concentration 128 mg/mL), OD=2.798, inhibition of lipid peroxidation; IC 50 =5.09± 0.25 and inhibition of haemolysis; with 12 mg/mL; 35 %. H. opuntia: DPPH; IC 50 50 =12.34 ± 0.30 mg/mL, reducing power; OD=0.800, inhibition of lipid peroxidation; IC 50 =1.25± 0.31 mg/mL, inhibition of lipid peroxidation; C =1.25± 0.31 mg/mL and inhibition of haemolysis; 82%. 50 Conclusion. It was demonstrated that B.triquetrum extract was more effective than H. opuntia in reducing power and DPPH assays while H.opuntia was more effective in inhibition of lipid peroxidation in rat brain homogenates and the inhibition of red blood cell (RBC) haemolysis induced by AAPH. We discuss some aspects about their possible mechanisms of action

Influence of metal ions and organic carbons on denitrification activity of the halotolerant bacterium, Paracoccus pantotrophus P16 a strain from shrimp pond

The effect of metal ions, ferric ion (Fe3+) and molybdenum ion (Mo6+) on the denitrification process of Paracoccus pantotrophus P16 grown under saline conditions was investigated. Results revealed that the dosages of added Fe3+ and Mo6+ significantly accelerated nitrate utilization and nitrite accumulation. Enzymatic studies revealed that the membrane-bound nitrate reductase and the periplasmic nitrite reductase had activities of 998 +/- 28 and 373 +/- 18 nmol (mg protein)-1 min-1, respectively after growing Paracoccus pantotrophus P16 in medium supplemented with 1.5 micron M Fe3+. If provided with 1.5 micron M Fe3+and 2.4 micron M Mo6+, the membrane-bound nitrate reductase activity increased to 6,223 +/- 502 nmol (mg protein)-1 min-1 and the periplasmic nitrite reductase was 344 +/- 20 nmol (mg protein)-1 min-1. The results indicated that an addition of Fe3+ and Mo6+ led to an overstimulation of nitrate reductase activity as compared with nitrite reductase activity. When glucose was supplied, the minimal ratio of carbon per nitrate (C/N) was 2.31 mg C/mg NO3--N with denitrification yield of 0.45 g NO3--N/g C. Addition of ethanol instead of glucose, the minimal ratio of C/N was 1.15 mg C/mg NO3--N with denitrification yield of 1.08 g NO3--N/g C.