The effect of the dietary substitution of fishmeal with tuna by‐product meal on growth,body composition,plasma chemistry and amino acid profiles of juvenile Korean rockfish (Sebastes schlegeli)

The effect of the substitution of fishmeal with tuna by‐product meal (TBM) in the diet of Korean rockfish on growth, body composition, plasma chemistry and amino acid profiles was determined. Nine experimental diets were prepared. The control (Con) diet consisted of 550 g kg^?1 fishmeal. The 10, 20, 30, 40, 60, 80 and 100 % fishmeal diets were substituted with tuna by‐product meal (TBM), referred to as the TBM10, TBM20, TBM30, TBM40, TBM60, TBM80 and TBM100 diets, respectively. Finally, the fishmeal and soybean meal was completely replaced with TBM in the diet TBM100‐S. There was no significant difference in weight gain and SGR of the fish that were fed the TBM40 and Con diets. The feed conversion ratio (FCR) of the fish that were fed the Con, TBM10, TBM20 and TBM30 diets was lower than that of the fish that were fed all of the other diets. The protein efficiency ratio (PER) of fish that were fed the TBM10, TBM20 and TBM300 diets was higher than that of fish that were fed the TBM40, TBM60, TBM80, TBM100 and TBM100‐S diets. It can be concluded that the substitution of fishmeal with up to 40 and 30 % TBM in the diet of juvenile Korean rockfish could be made without exerting a detrimental effect on their growth (SGR) and feed utilization (FCR and PER), respectively.     

Effect of dietary substitution of sea tangle (ST), Laminaria japonica with rice bran (RB) on growth and body composition of juvenile abalone (Haliotis discus)

Dietary substitution effect of sea tangle (ST) with rice bran (RB) on growth and carcass composition of juvenile abalone (Haliotis discus) was determined. Juvenile abalone was acclimated to the experimental conditions for 4 weeks. Seventy juvenile abalone averaging 0.43 g were randomly distributed into each of the 18, 70 L plastic rectangular containers. The experimental diets were fed to abalone once a day at a satiation level with a little leftover. The feeding trial lasted for 16 weeks. Survival of abalone was not affected by dietary substitution of ST with RB. However, weight gain of abalone fed the RB40 diet was higher than that of abalone fed the all other diets except for the RB0 diet. No significant difference in weight gain was found in abalone fed between the RB0 and RB100 diets. SGR of abalone fed the RB40 diet was higher than that of abalone fed the all other diets. Also SGR of abalone fed the RB0 diet was higher than that of abalone fed the RB100 diet, but not different from that of abalone fed the RB20, RB60 and RB80 diets. Moisture, crude protein and ash content of the soft body of abalone were affected by dietary substitution of ST with RB. In conclusion, the 100% ST could be substituted with RB without a retardation of weight gain of abalone when the 20% ST was included into the experimental diet. However, the best growth performance was obtained in abalone fed the RB40 diet substituting 40% ST with RB.     

Rapid selection of catechin-rich tea trees (Camellia sinensis) by a colorimetric method

A rapid and efficient colorimetric method based on the use of Fast Blue B-salt (FBB) was established to select catechin-rich tea trees (Camellia sinensis L.). The catechin levels measured by the colorimetric method under optimized reaction conditions correlated closely with estimations by high-performance liquid chromatography (HPLC) analysis. The FBB colorimetric method was successfully used to classify 160 tea trees on the basis of their catechin contents into rich and poor lines. HPLC analysis of the FBB-selected tea tree extracts showed them to contain (−)-epigallocatechin 186 mg/g in tea tree line HR-29, (−)-epicatechin 43.7 mg/g in HR-82, (−)-epigallocatechin gallate 4.32 mg/g in HR-29, and (−)-epicatechin gallate 0.22 mg/g in HR-52. Classification of tea trees from the Hadong region into catechin-rich and -poor trees was independent of the growing season. Thus the FBB colorimetric method could find application as a reliable tool in screening and selection of tea trees on the basis of their catechin content.     

Preliminary trials of the BioBaler working in Brazilian eucalypt plantations

The increasing demand for renewable energy feedstock has raised interest in growing eucalypts for fuel wood production, which is achieved by establishing very dense plantations cut every 18–24 months. The high moisture content of fresh Eucalyptus may handicap cut-and-chip operations, and offers a unique opportunity for supply chains based on baling. Therefore, the Canadian-made BioBaler was tested in Brazil on a eucalypt energy plantation, as well as on the resprouts generated by a conventional pulpwood plantation after severe frost damage. The BioBaler coped well with both crops, achieving high productivity levels: 7.1 and 3.3 t h^?1 in the energy plantation and the failed crop treatments, respectively. Harvesting cost was estimated at €13 t^?1 and €26 t^?1 for the energy plantation and the failed crop, respectively. Productivity and harvesting cost were comparable with those reported in previous studies conducted in other countries on similar crops. Productivity was directly proportional to field stocking. Future studies should test the machine on a wider range of work conditions and include bale extraction, storage, processing and transportation, in order to estimate an overall supply chain cost and allow direct comparison with alternative options.     

Development of real‐time and quantitative QCM immunosensor for the rapid diagnosis of Aeromonas hydrophila infection

Since bacterial infection cause a significant economic loss in fish farms, it is necessary to develop rapid diagnostic tools. Interests on label‐free biosensors have been raised for the rapid detection of aquatic pathogenic bacteria but have not been extensively studied yet. Here we report a quartz crystal microbalance (QCM) immunosensor system for the rapid and simple detection of Aeromonas hydrophila, a pathogen for fish and human, in comparison with a conventional indirect ELISA method. In QCM immunosensor system, an antibody against A. hydrophila was covalently cross‐linked to the gold surface of sensor chip and bacterial attachment was monitored as real‐time frequency shifts within 5 min. The frequency shifts were very positively related to the amounts of bacterial cells between 6.25 and 100 μg corresponding to 6 × 10⁶ to 10⁸ CFU with a high specificity. The QCM immunosensor was also able to detect bacterial cells in fish tissue extract in a dose‐dependent manner. Indirect ELISA also showed the dose‐dependent reaction and the amplified signal may allow a lower detection limit. However, QCM immunosensor system showed a more linear and reliable standard curve with R² value of almost 1 (0.9999). Moreover, detection of the bacteria was much quicker and simpler.     

Large-scale molecular dynamics simulations of dislocation intersection in copper

The results of massively parallel three-dimensional molecular dynamics simulations of the perpendicular intersection of extended dislocations in copper are reported. The intersection process, which involves three of the four possible 111 glide planes in the face-centered cubic lattice, begins with junction formation, followed by unzipping, partial dislocation bowing, cutting, and, finally, unit jog formation. The investigation provides insights into this complex atomistic process, which is currently not accessible to experimental investigation.     

Biosynthesis of trans-2-hexenal in response to wounding in strawberry fruit

Wounded strawberry fruit produces a diverse group of volatile compounds including aldehydes, alcohols, and esters derived from the lipoxygenase (LOX) and hydroperoxide lyase (HPL) pathways. Because the wound volatiles may play an important role in plant-fungal interaction, the goal of this study was to develop a greater understanding about the biosynthesis of the major wound volatile, trans-2-hexenal (t-2-H), produced by strawberry fruit upon wounding. To that end, composition and quantity of total and free fatty acids of control and wounded strawberry fruit were analyzed. In addition, activities of the key enzymes, LOX and HPL, and production of C6 aldehydes were determined. Intact strawberry fruit did not produce detectable t-2-H which is derived from alpha-linolenic acid (18:3). However, in response to wounding by bruising, strawberry fruit emitted t-2-H and its precursor cis-3-hexenal (c-3-H). The level of total lipid 18:3 in the fruit increased 2-fold in response to wounding, whereas free 18:3 declined slightly ( approximately 30%). At 10 min following wounding, fruit exhibited a 25% increase in LOX activity, which leads to the production of 13-hydroperoxyoctadecatrienoic acid (13-HPOT) from 18:3. The activity of HPL, which catalyzes formation of cis-3-hexenal from 13-HPOT, increased 2-fold by 10 min after wounding. Thus, during a 15 min period after wounding, free 18:3 substrate availability and the activity of two key enzymes, LOX and HPL, changed in a manner consistent with increased c-3-H and t-2-H biosynthesis.     

Appearance of Infectious Hematopoietic Necrosis Virus in Rainbow Trout,Oncorhynchus mykiss,During Seawater Adaptation

About 7% mortality occurred in rainbow trout, Oncorhynchus mykiss, during seawater adaptation at a marine farm in the South Sea of Korea during the winter of 2014. Most diseased fish showed petechial hemorrhaging of gills and internal fat with enlarged spleen. Although no parasites or bacteria were isolated from the diseased fish, all tissue filtrates produced cytopathic effects (CPEs) in fathead minnow and Chinook salmon embryo‐214 cells. The cell culture supernatant showing CPE contained specific 1527‐bp fragment for the infectious hematopoietic necrosis virus (IHNV) glycoprotein gene by polymerase chain reaction. Their nucleotide sequences shared 98.1–98.2% identities with IHNV RtUi02 isolated from rainbow trout in Korea. This isolate (RtGoH14) was closely related to Korean IHNV isolates of genogroup JRt rather than to those of North American and European genogroups. These results suggest that this IHNV isolate might have been introduced to rainbow trout farm (land‐based culture system) in Korea. This is the first report of IHNV infection in rainbow trout during seawater adaptation in Korea.     

SSR marker tightly linked to the Ti locus in Soybean [Glycine max (L.) Merr.]

Soybean is a major source of protein meal in the world. Soybean kunitz trypsin inhibitor (SKTI) protein is a responsible for the inferior nutritional quality of unheated or incompletely heated soybean meal. The primary objective of this research was to identify DNA markers linked to the Ti locus controlling presence and absence of kunitz trypsin inhibitor protein. Two mapping populations were developed. Population 1 was derived from a cross between cultivar Jinpumkong2 (TiTi) and C242 (titi). Population 2 was made from a mating between cultivar Clark (TiTi) and C242. The F₁ plants were grown in the greenhouse to produce F₂ seeds. Each F₂ seed from F₁ plants was analyzed electrophoretically to determine the presence of the SKTI protein band. One-thousand RAPD primers, 342 AFLP primer sets, and 35 SSR primers were used to map Ti locus in population 1 and 2. The presence of SKTI protein was dominant to the lack of a SKTI protein and kunitz trypsin inhibit protein band was controlled by a single locus. Twelve DNA markers (4 RAPD, 4 AFLP, and 3 SSR) and Ti locus were found to be genetically linked in population 1 consisted with 94 F₂ individual plants. Three SSR markers (Satt409, Satt228, and Satt429) were linked with Ti locus within 10 cM. Satt228 marker was tightly linked with Ti locus. Satt228 marker was tightly linked within 0–3.7 cM of the Ti locus and may be useful in a marker assisted selection program.     

Generation of transgenic corn-derived Actinobacillus pleuropneumoniae ApxIIA fused with the cholera toxin B subunit as a vaccine candidate

Corn, one of the most important forage crops worldwide, has proven to be a useful expression vehicle due to the availability of established transformation procedures for this well-studied plant. The exotoxin Apx, a major virulence factor, is recognized as a common antigen of Actinobacillus (A.) pleuropneumoniae, the causative agent of porcine pleuropneumonia. In this study, a cholera toxin B (CTB)-ApxIIA#5 fusion protein and full-size ApxIIA expressed in corn seed, as a subunit vaccine candidate, were observed to induce Apx-specific immune responses in mice. These results suggest that transgenic corn-derived ApxIIA and CTB-ApxIIA#5 proteins are potential vaccine candidates against A. pleuropneumoniae infection.