1. Comparison of the properties of phosphoglucomutase from muscle of turbot (Reinhardtius hippoglossoides, Greenland Halibut) and witch flounder (Glyptocephalus cynoglossus) from the Northwest Atlantic and the Gulf of St. Lawrence
A C Dey Comp Biochem Physiol B. 1982;72(2):249-54. doi: 10.1016/0305-0491(82)90042-6.
1. Phosphoglucomutase from muscle of turbot and witch has been purified and the properties studied from two regions of the Northwest Atlantic and the Gulf of St. Lawrence. 2. The enzyme, purified 157 fold from turbot and 164 fold from witch had specific activities of 596 and 475 U/mg/min respectively. 3. The M.W. and pH optimum of the enzyme from both species were 63,500 and 7500; and 63,000 and 7800 for the Northwest Atlantic and the Gulf samples respectively. 4. The amino acid contents and responses towards different inhibitory agents were different for the enzyme from the Gulf than the Northwest Atlantic samples. 5. The findings compares well with the genetic analysis of the electrophoretic properties of the enzyme in relation to stock discrimination of the two species.
2. A netting-based alternative to rigid sorting grids in the small-meshed Norway pout (Trisopterus esmarkii) trawl fishery
Ole R Eigaard, Bent Herrmann, Jordan P Feekings, Ludvig A Krag, Claus R Sparrevohn PLoS One. 2021 Jan 28;16(1):e0246076. doi: 10.1371/journal.pone.0246076. eCollection 2021.
A new bycatch reduction device, termed "Excluder", is presented as an alternative to a traditional rigid sorting grid, mandatory in the small-meshed Norway Pout (Trisopterus esmarkii) trawl fishery in the North Sea. The fishery is a high-volume fishery with large vessels, large demersal trawls and catches up to 100 tons per haul of this small forage fish. The Excluder is a 30 m long netting-based sorting system, developed to reduce bycatch (70 mm square meshes) and improving on board gear-handling and safety. The Excluder was tested against a 5.8 m2 standard sorting grid (35 mm bar spacing) in a twin-trawl experiment from the commercial 70 m trawler "S364 Rockall". Catch data were analysed by species and length using the catch comparison method. For all bycatch species analysed, the Excluder had significantly lower catches relative to the grid: herring (21%), whiting (6%), mackerel (5%), American plaice (70%), witch flounder (15%), and lesser silver smelt (71%). For Norway Pout there was a significant increase in the overall catch efficiency of 32%. These results are explained by a 10 cm smaller L50 (the length of fish with 50% probability of being rejected by the sorting system) of the Excluder and a 15 times larger sorting area, which reduces the risk of clogging and loss of function. With these documented effects of improved sorting and target species catch efficiency, implementation of the Excluder would improve sustainability and address two main barriers of the current Norway pout fishery that limit quota capitalization; a tendency for Norway pout to mix with herring and whiting and lowered catch rates from grid-clogging. Additionally, gear-handling and safety on board would be improved.
3. Anti-microbial, anti-biofilm activities and cell selectivity of the NRC-16 peptide derived from witch flounder, Glyptocephalus cynoglossus
Ramamourthy Gopal, Jun Ho Lee, Young Gwon Kim, Myeong-Sun Kim, Chang Ho Seo, Yoonkyung Park Mar Drugs. 2013 May 28;11(6):1836-52. doi: 10.3390/md11061836.
Previous studies had identified novel antimicrobial peptides derived from witch flounder. In this work, we extended the search for the activity of peptide that showed antibacterial activity on clinically isolated bacterial cells and bacterial biofilm. Pseudomonas aeruginosa was obtained from otitis media and cholelithiasis patients, while Staphylococcus aureus was isolated from otitis media patients. We found that synthetic peptide NRC-16 displays antimicrobial activity and is not sensitive to salt during its bactericidal activity. Interestingly, this peptide also led to significant inhibition of biofilm formation at a concentration of 4-16 μM. NRC-16 peptide is able to block biofilm formation at concentrations just above its minimum inhibitory concentration while conventional antibiotics did not inhibit the biofilm formation except ciprofloxacin and piperacillin. It did not cause significant lysis of human RBC, and is not cytotoxic to HaCaT cells and RAW264.7 cells, thereby indicating its selective antimicrobial activity. In addition, the peptide's binding and permeation activities were assessed by tryptophan fluorescence, calcein leakage and circular dichroism using model mammalian membranes composed of phosphatidylcholine (PC), PC/cholesterol (CH) and PC/sphingomyelin (SM). These experiments confirmed that NRC-16 does not interact with any of the liposomes but the control peptide melittin did. Taken together, we found that NRC-16 has potent antimicrobial and antibiofilm activities with less cytotoxicity, and thus can be considered for treatment of microbial infection in the future.
