Ocean Pout Research Articles

Evaluation of corn steep liquor as fermentation media for recombinant Lactococcus lactis producing antifreeze proteins.

Corn processing byproducts corn steep liquor (CSL), and thin stillage were evaluated as growth media for recombinant Lactococcus lactis modified to produce antifreeze proteins (AFPs) that could have important food and non-food applications. The AFP III sequence from ocean pout was cloned into a shuttle vector to make an expression vector that facilitated the production of recombinant AFP III in Lactococcus lactis. Light CSL from yellow dent corn and thin stillage from the industrial corn bioethanol process were optimized as fermentation media with a combination of the following additives and trace elements: disodium-β-glycerophosphate (DG), tryptone (T), ascorbic acid (AA), iron (Fe), zinc (Zn), and magnesium (Mg). The growth of wild-type and recombinant Lactococcus lactis strains were compared over a 72 h period in 96-well plates and 250 mL shake flasks. The corn coproducts media consisting of 50% (v/v) light steep in water supplemented with DG-5g L-1 , T-5g L-1 , AA-0.5g L-1 , and Zn-4ppm resulted in best growth and was considered as the best-optimized media. The addition of additives and trace elements better supported the growth of both wild-type and recombinant Lactococcus lactis strains compared to control media without any additives. Respective fermentation supernatants were frozen to -20 °C, and the time to supercool and freeze was compared. A distinct supercooling effect was observed for the supernatants from recombinant strains thus, extending the time and temperature of supercooling and freezing. The maximum time of supercooling extended was 17.55 ± 4.45 min for thin stillage followed by M17 media (17.25 ± 4.45 min), Kent Corporation CSL (10.80 ± 2.12 min), and yellow dent CSL (6.9 ± 0.85 min) when fermented with recombinant Lactococcus lactis strains. The supplemented corn coproduct-based media enhanced the growth of both wild-type and recombinant Lactococcus lactis strains. These optimized media can replace or supplement more expensive media (e.g. M17), potentially reducing cost. The fermentation supernatants exhibited longer times to supercool, and freeze compared to control supernatants, indicating potential use as antifreeze compounds in frozen food and non-food applications. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Comparison of growth performance among channel-blue hybrid catfish, ccGH transgenic channel catfish, and channel catfish in a tank culture system

Fish is an essential source of high-quality protein for people worldwide. The present study was designed to compare the growth performance among the channel-blue hybrid catfish, channel catfish transgenic for the channel catfish growth hormone (ccGH) cDNA driven by the antifreeze protein promoter from an ocean pout Zoarces americanus (opAFP-ccGH), and non-transgenic channel catfish control. Mean body weight of channel-blue hybrid catfish was 15.80 and 24.06% larger than non-transgenic channel catfish control at 4 and 18 months of age, respectively. However, transgenic opAFP-ccGH channel catfish were 5.52 and 43.41% larger than channel-blue hybrid catfish and 22.19 and 77.91% larger than their controls at 4 and 18 months of age, respectively. Significant differences in mean body weight between the sexes within all genetic types were found. Males were larger than females (P < 0.001). However, mean body weight of non-transgenic males was not larger than transgenic opAFP-ccGH females or male and female hybrid catfish. Condition factor of transgenic opAFP-ccGH channel catfish was higher (P < 0.05) than that of full-sibling, non-transgenic channel catfish and hybrid catfish. The mean percentage body weight gain of GH transgenic channel catfish was 559%, the channel-blue hybrid catfish was 384.9% and their non-transgenic controls channel catfish was 352.6%.

Pleistophora macrozoarcidis . [Descriptions of Fungi and Bacteria

Abstract A description is provided for Pleistophora macrozoarcidis , the only microsporidian recorded from Zoarces americanus , the ocean pout, a North Atlantic fish of the order Perciformes. Some information on its morphology, dispersal and transmission and conservation status is given, along with details of its geographical distribution (North America (Canada, Quebec, USA, Connecticut, Massachusetts, Rhode Island)) and host ( Zoarces americanus ).

Growth Differences of Growth Hormone Transgenic Female and Male Channel Catfish, Ictalurus punctatus, Grown in Earthen Ponds to Sexual Maturation.

This study compared growth performance between female and male transgenic channel catfish, Ictalurus punctatus, containing channel catfish growth hormone full-length cDNA driven by the ocean pout antifreeze protein promoter, opAFP-ccGH, the rainbow trout metallothionein promoter, rtMT-ccGH, or both constructs, and their non-transgenic siblings in earthen ponds at 16 and 48months of age. Body weight between the transgenic and their non-transgenicsiblings differed (P < 0.001) at all ages. Transgenic F2 opAFP-ccGH grew 1.51- to 2.58-, F2 rtMT-ccGH grew 1.44- to 2.99- and F1fish transgenic for both constructs grew 1.36- to 2.92- fold larger than their non-transgenicsibling controls, depending upon age and sex. Body weight of the transgenic GH males was significantly higher than those of the transgenic GH females at 16months of age (P < 0.001). However, body weight of the transgenic GH females was significantly higher (P < 0.001) compared with those of the transgenic GH males at 48months of age, but not for the double transgenics (P > 0.05). In the case of non-transgenic GH siblings, males were larger than females at both 16 and 48months of age (P < 0.001). Sexually dimorphic responses to GH transgenes were the opposite after sexual maturation. When critically low dissolved oxygen levels were encountered, survival of transgenic male and female opAFP-ccGH channel catfish was lower than that of controls (P = 0.004), as well as rtMT-ccGH females (P = 0.11), which is not surprising since the largest fish are most likely to succumb during an oxygen depletion.

Effects of family and promoter on growth performance of ccGH cDNA transgenic channel catfish, Ictalurus punctatus, grown in a trough culture system

Constructs bearing growth hormone (GH) cDNA from channel catfish, Ictalurus punctatus, driven by the ocean pout, Zoarces americanus, antifreeze protein promoter (opAFP), or by the rainbow trout, Oncorhynchus mykiss, metallothionein promoter (rtMT) were transferred to channel catfish via electroporation. Transgenic P1 individuals were mated to produce F1 individuals that exhibited enhanced growth rate. The inheritance of the transgene by the F1 generation was 10% to 36%. The mean body sizes of F1 transgenic fish were larger than their non-transgenic full-siblings (P < 0.001). Transgenic channel catfish harboring channel catfish growth hormone (ccGH) cDNA, driven by the ocean pout antifreeze protein promoter (opAFP) grew 1.41- to 1.62- fold larger than their non-transgenic full-siblings, and transgenic channel catfish possessing the channel catfish growth hormone (ccGH) cDNA, driven by the rainbow trout metallothionein promoter (rtMT) grew 1.23- to 1.78- fold larger than their non-transgenic full-siblings. However, non-transgenic full-siblings in one family of opAFP-ccGH had the same mean size as transgenic individuals of a another family, and non-transgenic full-siblings in two families of rtMT-ccGH had the same mean size as transgenic individuals of a third family that was the slowest growing family, illustrating the importance of the family effect (P < 0.001) or possibly variable insertion sites. The slowest growing family exhibited the greatest observed response to the GH transgene insertion. Condition factor was not different (P > 0.05) between transgenic and non-transgenic full-siblings except for one opAFP-ccGH family, although the observed means were smaller for four of six transgenic groups as apparently their relative length was increasing more rapidly than relative weight compared to their respective controls. Examining the data from the current experiment and that from an earlier experiment with the same genetic types, but grown to a smaller size, it appears that the two promoters gave similar results in regards to growth enhancement. The largest individuals were always in the transgenic families, and this along with the family effects suggest that gene transfer coupled with combined individual and family selection might result in larger fish than the GH transgenesis alone. The growth enhancement in the current experiment was better than previous experiments with channel catfish that used RSV-LTR-salmonid GH constructs. Assuming government approval and the same growth to food size, GH transgenic channel catfish would increase farm income by $3421/ha compared to use of non-transgenic channel catfish.

Data Recovery from Old Filing Cabinets: Seasonal Diets of the Most Common Demersal Fishes in the Miramichi River Estuary (Atlantic Canada), 1991–1993

A recent data-recovery exercise uncovered a large amount of stomach-content data (n = 8209) from mainly demersal fishes collected seasonally in the Miramichi River Estuary, southern Gulf of St. Lawrence (sGSL), 1991–1993. Of the demersal species captured, all but Pleuronectes putnami (Smooth Flounder) represent transient species. Within the estuary, stomach samples were collected from all species (except Osmerus mordax [Rainbow Smelt]) captured by trawling and in commercial trap nets. Rainbow Smelt stomachs were collected during trawl surveys (May through October) in nearby coastal waters. The summer diet analyses were limited to Smooth Flounder (small bivalve specialist), Pseudopleuronectes americanus (Winter Flounder), and Rainbow Smelt. Many juvenile Urophycis tenuis (White Hake) entered the estuary during late September to feed and then departed during November. Numerous Gadus macrocephalus (Greenland Cod), Myoxocephalus scorpius (Shorthorn Sculpin), Winter Flounder, juvenile Clupea harengus (Atlantic Herring), Microgadus tomcod (Atlantic Tomcod), Rainbow Smelt, Morone saxatilis (Striped Bass), and Zoarces americanus (Ocean Pout) entered the estuary during autumn to overwinter, spawn, and feed. Winter Flounder, Smooth Flounder, Striped Bass, and Atlantic Herring fasted during winter. Crangon septemspinosa (Seven-spined Bay Shrimp) was the most important invertebrate prey (up to 95% of total prey mass) of all transient species. Large specimens of Greenland Cod, Shorthorn Sculpin, Ocean Pout, and White Hake also ate substantial numbers of small Rainbow Smelt, Atlantic Herring, Striped Bass, and Atlantic Tomcod. When combined with published data for the adjacent coastal zone, C. septemspinosa represents a nexus in 2 food webs and fits the description of a keystone species for the sGSL coastal zone and adjacent estuaries.

Computational Study of Differences between Antifreeze Activity of Type-III Antifreeze Protein from Ocean Pout and Its Mutant.

The antifreeze activity of a type-III antifreeze protein (AFP) expressed in ocean pout (Zoarces americanus) is compared with that of a specific mutant (T18N) using all-atom molecular dynamics simulations. The antifreeze activity of the mutant is only 10% of the wild-type AFP. The results from this simulation study revealed the following insights into the mechanism of antifreeze action by type-III AFPs. The AFP gets adsorbed to the advancing ice front due to its hydrophobic nature. A part of the hydrophobicity is caused by the presence of clathrate structure of water molecules near the ice-binding surface (IBS). The mutation in the AFP disrupts this structure and thereby reduces the ability of the mutant to adsorb to the ice-water interface leading to the loss of antifreeze activity. The mutation, however, has no effect on the ability of the adsorbed protein to bind to the growing ice phase. Simulations also revealed that all surfaces of the protein can bind to the ice phase, although the IBS is the preferred surface.

Genotype-environment interactions for survival and growth rate at varying levels of sodium chloride for growth hormone transgenic channel catfish (Ictalurus punctatus), channel catfish, and albino channel catfish

Lack of freshwater is emerging as the most critical natural resource issue facing humanity. Ongoing climate change will reduce freshwater supplies, and demand for food continues to expand rapidly. Swim-up channel catfish, Ictalurus punctatus, fry transgenic for the channel catfish growth hormone (GH) gene driven by the rainbow trout Oncorhynchus mykiss metallothionein promoter (rtMT-ccGH), or by the ocean pout Zoarces americanus antifreeze protein promoter (opAFP-ccGH), channel catfish, and albino channel catfish were grown at 0, 2.5, 5, and 7.5 parts per thousand (ppt) salinity. Survival was 100% for all genetic groups at 0 and 2.5 ppt. Increasing salinity to 5 ppt decreased overall survival as survival rates of rtMT-ccGH transgenic (T), rtMT-ccGH control (C), opAFP-ccGH transgenic (T), opAFP-ccGH control (C), channel catfish, and albino channel catfish were 83, 82, 83, 77, 89 and 40%, respectively. Increasing salinity to 7.5 ppt had a strong negative impact on survival as means for rtMT-ccGH (T), rtMT-ccGH (C), opAFP-ccGH (T), opAFP-ccGH (C), channel catfish, and albino channel catfish were 67, 13, 67, 10, 18, and 7%, respectively with the albino channel catfish having the lowest survival followed by opAFP-ccGH (C) (P = .002). Raising salinity to 2.5 ppt greatly increased the growth rate of GH transgenic channel catfish (11–33%), channel catfish (56%), and albino channel catfish (124%). NaCl had a negative effect on survival and growth rate for swim-up fry at 5 ppt. Significant differences were observed at varying salinity (P < .0001) for final body weights among genetic groups. Condition factor, growth and survival were not perfectly correlated, and genotype-environment interactions occurred for the overall phenotype. Apparently, GH can play a critical positive role for channel catfish under osmotic stress, which has relevance for aquaculture management under future global climate change. Optimum performance for all genotypes was observed with slightly elevated, 2.5 ppt. Although, GH transgenic catfish were less affected than non-transgenic channel catfish at 5–7.5 ppt, their performance was sub-optimal. GH transgenic fish are beneficial for use in culture environments that have slight shifts in salinity in the future, but they are only a partial solution for future environments at 5 ppt and higher.

In silico structural and functional modelling of Antifreeze protein (AFP) sequences of Ocean pout (Zoarces americanus, Bloch & Schneider 1801).

Antifreeze proteins (AFPs) are known to polypeptide components formed by certain plants, animals, fungi and bacteria which support to survive in sub-zero temperature. Current study highlighted the seven different antifreeze proteins of fish Ocean pout (Zoarces americanus), in which protein (amino acids sequence) were collected from National Centre for Biotechnology Information and finely characterized using several in silico tools. Such biocomputational techniques applied to figure out the physicochemical, functional and conformational characteristics of targeted AFPs. Multiple physicochemical properties such as Isoelectric Point, Extinction Coefficient and Instability Index, Aliphatic Index, Grand Average Hydropathy were calculated and analysed by ExPASy-ProtParam prediction web server. EMBOSS: pepwheel online tool was used to represent the protein sequences in a helical form. The primary structure analysis shows that most of the AFPs are hydrophobic in nature due to the high content of non-polar residues. The secondary structure of these proteins was calculated using SOPMA tool. SOSUI server and CYS_REC program also run for ideal prediction of transmembrane helices and disulfide bridges of experimental proteins respectively. The modelling of 3D structures of seven desired AFPs were executed by the homology modelling programmes; SWISS MODEL and ProSA web server. UCSF Chimera, Antheprot 3D, PyMOL and RAMPAGE were used to visualize and analysis of the structural variation of the predicted protein model. MEGA7.0.9 software used to know the phylogenetic relationship among these AFPs. These models offered excellent and reliable baseline information for functional characterization of the experimentally derived protein domain composition by using the advanced tools and techniques of Computational Biology.

Effect of glycosylation on hydration behavior at the ice-binding surface of the Ocean Pout type III antifreeze protein: a molecular dynamics simulation

Antifreeze proteins (AFPs), found in certain vertebrates, plants, fungi and bacteria have the ability to permit their survival in subzero environments by thermal hysteresis mechanism. However, the exact mechanism of ice growth inhibition is still not clearly understood. Here, four long explicit molecular dynamics (MD) simulations have been carried out at two different temperatures (277 and 298 K) with and without glycan to study the conformational rigidity of the Ocean pout type III antifreeze protein in aqueous medium and the structural arrangements of water molecules hydrating its ice-binding surface. It is found that irrespective of the temperature the ice-binding surface (IBS) of the protein is relatively more rigid than its non ice-binding surface (NonIBS) in its native and glycosylated form. Hydrophilic residues N14, T18 and Q44 are essential to antifreeze activity. Radial distribution, density distribution function and nearest neighbor orientation plots with respect to individual two surfaces confirm that density of water molecule near these binding surface in native and glycosylated form are relatively more than the nonbinding surface. The glycosylated form shows a strong peak than the native one. From rotational auto correlation function of water molecules around ice-binding sites, it is prominent that with increase in temperature, strong interaction between the water oxygen and the hydrogen bond acceptor group on the protein-binding surface decreases. This provides a possible molecular reason behind the ice-binding activity of ocean pout at the prism plane of ice.

Ultrastructural characterization of Pleistophora macrozoarcidis Nigerelli 1946 (Microsporidia) infecting the ocean pout Macrozoarces americanus (Perciformes, Zoarcidae) from the gulf of Maine, MA, USA.

Pleistophora macrozoarcidis a microsporidian parasite infecting the muscle tissue of the ocean pout Macrozoarces americanus collected from the Gulf of Maine of the Atlantic Ocean, MA, USA, was morphologically described on the basis of ultrastructural features. Infection was detected as opaque white or rusty brown lesions scattered throughout the musculature of the fish mainly in the region anterior to anus. Transmission electron microscopy showed that in individual parasitized muscle cells, the infection progresses within parasite formed vesicles which are in direct contact with muscle cell elements. The earliest observed parasitic stages are the globular multinucleated proliferative cells or plasmodia limited by a highly tortuous plasmalemma with intervesicular finger-like digitations projecting into the parasite cytoplasm. These cells divided through the invagination of the plasmalemma and the amorphous coat producing daughter-cells. Fine electron-dense secretion is deposited on the plasmalemma that causes its thickening which is a sign of commencement of the sporogonic phase. This phase is carried out by cytokinesis of the sporonts and results in the formation of sporoblasts and finally spores. Mature spore has a thin electron-dense exospore, a thick electron-lucent endospore, and the plasma membrane which encloses the spore contents. A single nucleus is centrally located with the posterior region containing a posterior vacuole. The majority of spores have 7-13 coils in 1-2 rows, and a small group of spores had about 23 coils forming two rows. Events of polar filament extrusion for penetration of uninfected cells were studied. The polaroplast membranes were expanded and occupy most of the length of the spore. The coils are dislocated from the sides of the spore to throughout the entire sporoplasm. The polar filament everts and extrudes through the polar cap with a sufficient force to pierce adjacent sporophorous vesicle walls. After eversion, the polar filament is referred to as a polar tubule, as it forms a tube through which the sporoplasm travels. It pierces anything in its path and deposits the sporoplasm at a new location to begin another infective cycle.

Structure of solvation water around the active and inactive regions of a type III antifreeze protein and its mutants of lowered activity.

Water molecules from the solvation shell of the ice-binding surface are considered important for the antifreeze proteins to perform their function properly. Herein, we discuss the problem whether the extent of changes of the mean properties of solvation water can be connected with the antifreeze activity of the protein. To this aim, the structure of solvation water of a type III antifreeze protein from Macrozoarces americanus (eel pout) is investigated. A wild type of the protein is used, along with its three mutants, with antifreeze activities equal to 54% or 10% of the activity of the native form. The solvation water of the ice-binding surface and the rest of the protein are analyzed separately. To characterize the structure of solvation shell, parameters describing radial and angular characteristics of the mutual arrangement of the molecules were employed. They take into account short-distance (first hydration shell) or long-distance (two solvation shells) effects. The obtained results and the comparison with the results obtained previously for a hyperactive antifreeze protein from Choristoneura fumiferana lead to the conclusion that the structure and amino acid composition of the active region of the protein evolved to achieve two goals. The first one is the modification of the properties of the solvation water. The second one is the geometrical adjustment of the protein surface to the specific crystallographic plane of ice. Both of these goals have to be achieved simultaneously in order for the protein to perform its function properly. However, they seem to be independent from one another in a sense that very small antifreeze activity does not imply that properties of water become different from the ones observed for the wild type. The proteins with significantly lower activity still modify the mean properties of solvation water in a right direction, in spite of the fact that the accuracy of the geometrical match with the ice lattice is lost because of the mutations. Therefore, we do not observe any correlation between the antifreeze activity and the extent of modification of the properties of solvation water.

Solvated and generalised Born calculations differences using GPU CUDA and multi-CPU simulations of an antifreeze protein with AMBER

While there has been an increase in the number of biomolecular computational studies employing graphics processing units (GPU), results describing their use with the molecular dynamics package AMBER with the CUDA implementation are scarce. No information is available comparing MD methodologies pmemd.cuda, pmemd.mpi or sander.mpi, available in AMBER, for generalised Born (GB) simulations or with solvated systems. As part of our current studies with antifreeze proteins (AFP), and for the previous reasons, we present details of our experience comparing performance of MD simulations at varied temperatures between multi-CPU runs using sander.mpi, pmemd.mpi and pmemd.cuda with the AFP from the fish ocean pout (1KDF). We found extremely small differences in total energies between multi-CPU and GPU CUDA implementations of AMBER12 in 1ns production simulations of the solvated system using the TIP3P water model. Additionally, GPU computations achieved typical one order of magnitude speedups when using mixed precision but were similar to CPU speeds when computing with double precision. However, we found that GB calculations were highly sensitive to the choice of initial GB parametrisation regardless of the type of methodology, with substantial differences in total energies.

New on the Menu: Genetically Modified Salmon

For the first time, the FDA has approved a genetically engineered animal as food—the AquAdvantage Salmon. The agency said the particular genetic modification introduced into the salmon meets the definition of a drug. The fish has a growth hormone gene from a Chinook salmon and a promoter sequence from another edible fish, the ocean pout, which activates the growth hormone gene. The result is an Atlantic salmon that reaches market size much more quickly than traditional farm-raised Atlantic salmon (http://1.usa.gov/1MEDh2k).

The Ocean Pout, &lt;em&gt;Zoarces americanus&lt;/em&gt;, and the Ocean Sunfish, &lt;em&gt;Mola mola&lt;/em&gt;: Additions to the Marine Ichthyofauna of the Lower Saint John River System, New Brunswick, with a Summary of Marine Fish Reported from the Estuary

Recent records for the Ocean Pout, Zoarces americanus (collected 11 February 2011), and the Ocean Sunfish, Mola mola (photograph taken 24 June 2012), in the lower Saint John River system, New Brunswick, add to the list of marine fishes reported from this oceanographically unique estuary system. A total of 62 species of strictly freshwater, anadromous, catadromous, and marine fishes have now been recorded in the Saint John River system, with 49 of these in the Saint John River sensu stricto. The Acadian Redfish, Sebastes faciatus, a species assessed as threatened by the Committee on the Status of Endangered Wildlife in Canada, appears to be among these. While strictly marine fishes may contribute relatively little to the overall biomass of fishes in the Saint John River system, marine species account for 30.6% of the biodiversity of fishes in the river to date. This suggests that marine fishes may be a more significant component of the ichthyofauna of the lower Saint John River system than is generally recognized.

Functional evaluation of candidate ice structuring proteins using cell-free expression systems

Ice structuring proteins (ISPs) protect organisms from damage or death by freezing. They depress the non-equilibrium freezing point of water and prevent recrystallization, probably by binding to the surface of ice crystals. Many ISPs have been described and it is likely that many more exist in nature that have not yet been identified. ISPs come in many forms and thus cannot be reliably identified by their structure or consensus ice-binding motifs. Recombinant protein expression is the gold standard for proving the activity of a candidate ISP. Among existing expression systems, cell-free protein expression is the simplest and gives the fastest access to the protein of interest, but selection of the appropriate cell-free expression system is crucial for functionality. Here we describe cell-free expression methods for three ISPs that differ widely in structure and glycosylation status from three organisms: a fish (Macrozoarces americanus), an insect (Dendroides canadensis) and an alga (Chlamydomonas sp. CCMP681). We use both prokaryotic and eukaryotic expression systems for the production of ISPs. An ice recrystallization inhibition assay is used to test functionality. The techniques described here should improve the success of cell-free expression of ISPs in future applications.

Characterizing variation in Northwest Atlantic fish-stock abundance

Abstract Rothschild, B. J., and Jiao, Y. 2012. Characterizing variation in Northwest Atlantic fish-stock abundance. – ICES Journal of Marine Science, 69: 913–922. Catch-per-tow indices obtained by research vessels for the years 1963–2009 from NAFO statistical areas 4W, 4X, 5Y, and 5Z were studied to determine how fish “apparent abundance” in the decade 2000–2009 differed from the long-term time-series. Cluster analysis of normalized catch-per-tow data indicated that the abundance and species composition of stocks in each statistical area changed dramatically over the 50-year period. There were decreases in thorny skate, ocean pout, cusk, witch flounder, and monkfish and increases in herring, haddock, northern shrimp, and spiny dogfish. Cluster analysis suggested that these decreases and increases were not gradual, but abrupt, and that these abrupt decreases and increases were concentrated in the decade of the 1980s. Observations of abrupt change were supported by regression-tree analysis of individual stocks. Examination of the interrelationship among abundance indices from different stocks by Bonferroni-adjusted correlation coefficients showed that the abundance trajectories of most stocks were uncorrelated. It appears that the set of population transitions during the decade of the 1980s was a dominant event in the statistical time-series.

Inhibition of Structure I and II Gas Hydrates using Synthetic and Biological Kinetic Inhibitors

Use of low-dosage hydrate inhibitors in oil and gas field applications has been limited mainly because there are uncertainties related to their efficiency in preventing hydrate formation or because of environmental restrictions. Another question that normally arises in connection with use of low-dosage hydrate inhibitors is how they interact with other (than water) compounds normally found in oil and gas production pipelines. In this work three different experimental approaches to obtain hydrate induction times have been tested for structure I and II hydrate. All experiments were conducted in a high-pressure stirred cell. The results suggest that by adding small amounts of impurities to the hydrate-forming system a significant improvement in the reproducibility of induction times can be obtained. Adding salt and heptane to the system (as a simple model for seawater and a light crude) was found to increase the hydrate formation rate. Ice-structuring protein type III identified in the ocean pout, a biologic...

Lysozyme transgenic Atlantic salmon (Salmo salar L.)

Disease outbreaks are a major constraint to salmon aquaculture worldwide. Therefore, there is considerable interest in finding means to alleviate this problem by enhancing their innate immune system. Because lysozyme is an important component of this system, we generated a line of transgenic Atlantic salmon using a gene construct consisting of a rainbow trout lysozyme gene under the control of the ocean pout antifreeze protein gene promoter op5a (opAFP-rtLys). The results show that the transgene exhibited Mendelian inheritance at both the F1 and the F2 generations and demonstrated that it had integrated into a single chromosome in the genetic founder. Sequence analysis of F2 generation salmon revealed the presence of a complete copy of an intact lysozyme transgene integrant that was identical in sequence to that of the construct. The computationally translated peptide sequence of the lysozyme coding region differed by four amino acids from those present in GenBank (accession nos CAA42084; AAG34564). Reverse transcriptase-polymerase chain reaction analysis demonstrated the expression of the transgene in most body tissues. However, Northern analysis revealed that visible levels of mRNA were only evident in the spleen, skin and kidney. The lysozyme lytic activity of kidney tissue extracts from F2 transgenic salmon was 40% greater than it was in non-transgenic siblings.

LAWS, REGULATIONS, AND POLICY: Genetically Engineered Salmon on the FDA’s Table

LAWS, REGULATIONS, AND POLICY: Genetically Engineered Salmon on the FDA’s Table