Growth,Feed Utilization,and Glycemic Response in European Sea Bass,Dicentrarchus labrax,Juveniles Fed Carbohydrate of Different Complexities

The effect of dietary carbohydrate complexity on growth, feed utilization, and glycemia was studied in European sea bass juveniles. Four isonitrogenous (50% crude protein) and isolipidic (15% crude lipids) diets were formulated to contain 20% pregelatinized maize starch (PGS diet), dextrin (DEX diet), maltose (MAL diet), or glucose (GLU diet). No effect of dietary carbohydrate complexity on growth was noticed. Feed efficiency and protein efficiency ratio were lower in fish fed the GLU diet than in the other groups, whereas the opposite was observed for feed intake. Plasma glucose peaked 3–4 h after feeding in fish fed the MAL and GLU diets, whereas in fish fed the PGS and DEX diets the peak was reached 5–6 h after feeding. Peak plasma glucose concentration (13 mmol/L) was higher in fish fed the GLU diet than the other diets (9 mmol/L). Shorter hyperglycemia duration was observed in fish fed the MALT and GLU diets (6 h) than the PGS and DEX diets (10 h). Complex carbohydrates delayed plasma glucose concentration peak compared with simple sugars, whereas the opposite was observed for hyperglycemia duration. Overall, dietary maltose, dextrin, and starch were apparently better utilized as energy source than glucose by European sea bass juveniles.     

Mineral contents of the muscle tissue and the digestive gland of Octopus vulgaris during short‐term starvation

We used spectrometry to study variation in the contents of minor (B, Cu, Fe, Mn and Zn) and major essential elements (Ca, K, Mg, Na and P) in the muscle tissue and digestive glands of Octopus vulgaris after 1, 2, 4 or 8 days of starvation and in fed controls. The contents of the major essential elements remained constant during 8 days of starvation. Na was the principal element found in both tissues, followed by K, P and Mg. The contents of the minor essential elements were higher in the digestive gland than in the muscle tissue, with increased contents of Fe, Mn and Zn (p < .05) during starvation, confirming the high capacity of this organ to accumulate trace minerals. In muscle tissues, B, Fe and Mn contents were lower and Cu and Zn contents higher, in starved animals than in fed animals (p < .05). Significant negative correlations between the digestive gland index and the contents of Cu, Fe and Zn suggested that the loss of weight of the digestive gland during starvation is responsible for this increase in mineral concentration. This and further information on variation in mineral content will help to optimize performance of diets formulated for the octopus.     

Effect of dietary betaine levels on growth performance and hepatic intermediary metabolism of GIFT strain of Nile tilapia Oreochromis niloticus reared in freshwater

An 8‐week feeding experiment was conducted to determine the effect of dietary betaine levels on the growth performance and hepatic intermediary metabolism of genetically improved farmed tilapia (GIFT) strain of Nile tilapia Oreochromis niloticus (mean initial body weight: 78.3 ± 1.3 g, means ± SD). Six practical diets were formulated with the incorporation of betaine at the levels of 0 (control), 5, 10, 15, 20 and 25 g kg⁻¹. Survival showed no significant differences among the treatments (P > 0.05). The highest and lowest weight gain (WG) and specific growth rate (SGR) were observed for fish fed the diets containing 5 and 0 g kg⁻¹ (control) betaine, respectively. Feed intake showed similar trend with WG and SGR. In contrast, feed conversion ratio was the lowest when dietary betaine level was 5 g kg⁻¹. In general, dietary betaine supplementation showed no significant effect on hepatic composition of tilapia. Condition factor and viscerosomatic index tended to increase with increasing dietary betaine levels from 0 to 5 g kg⁻¹ and then decline when dietary betaine levels further increased from 5 to 25 g kg⁻¹. In contrast, hepatosomatic index declined with increasing dietary betaine levels (P < 0.05). Dietary betaine levels significantly influenced several hepatic enzymatic activities, including succinate dehydrogenase, lactate dehydrogenase, malic dehydrogenase, lipoprotein lipase and hepatic lipase, suggesting that dietary betaine addition had significant effects on nutrient metabolism in the liver. Based on the second‐order polynomial regression analysis of WG, 12.5 g kg⁻¹ of dietary betaine level seemed optimal for genetically improved farmed tilapia strain of O. niloticus.     

Genetic analysis of ORF5 of recent Korean porcine reproductive and respiratory syndrome viruses (PRRSVs) in viremic sera collected from MLV-vaccinating or non-vaccinating farms

The 23 open reading frame (ORF) 5 sequences of Korean type II porcine reproductive and respiratory syndrome virus (PRRSV) were collected from viremic sera from the (modified live vaccine) MLV-vaccinating and non-vaccinating farms from 2007 to 2008. The samples were phylogenetically analyzed with previous ORF5 sequences, including type I Korean PRRSV, and previously reported or collected sequences from 1997 to 2008. A MN184-like subgroup of type II Korean PRRSV was newly identified in the viremic sera collected from 2007 to 2008. And of the type I PRRSVs, one subgroup had 87.2~88.9% similarity with the Lelystad virus, showing a close relationship with the 27~2003 strain of Spain. The maximum parsimony tree of type II PRRSV from 1997 to 2008 showed that they had evolved to four lineages, subgroups 1, 2, 3 and 4. Most of the recently collected type II PRRSVs belonged to subgroup 4 (48%). The region of three B-cell epitopes and two T-cell epitopes of ORF5 amino acids sequences was considerably different from the MLV in subgroups 3 and 4. In conclusion, the existence of type I PRRSV, which was genetically different from Lelystad virus (Prototype of type I PRRSV), and heterologous type II PRRSVs of viremic pigs detected even in the MLV-vaccinating farms indicated the need for new vaccine approaches for the control of PRRSV in Korea.     

QTL mapping for capsaicin and dihydrocapsaicin content in a population of Capsicum annuum ‘NB1’ × Capsicum chinense ‘Bhut Jolokia’

Capsaicinoids are pungent compounds used for industrial and medical purposes including food, medicine and cosmetics. The Indian local variety ‘Bhut Jolokia’ (Capsicum chinense Jacq.) is one of the world's hottest chilli peppers. It produces more than one million Scoville heat units (SHUs) in total capsaicinoids. In this study, our goal was to identify quantitative trait loci (QTLs) responsible for the high content of capsaicin and dihydrocapsaicin in ‘Bhut Jolokia’. Capsicum annuum ‘NB1’, a Korean pepper inbred line containing 14 000 SHUs, was used as a maternal line. An F₂ population derived by crossing between ‘NB1’ and ‘Bhut Jolokia’ was generated to map QTLs for capsaicinoids content. A total of 234 markers, including 201 HRM, 21 SSR, 2 CAPS and 10 gene‐based markers of the capsaicinoid synthesis pathway, were mapped. The final map covered a total distance of 1175.2 cM and contained 12 linkage groups corresponding to the basic chromosome number of chilli pepper. Capsaicin and dihydrocapsaicin content were analysed in 175 F₂ pepper fruits using the HPLC method. The maximum total capsaicinoids content was 1389 mg per 100g DW (dry weight), and the minimum content was 11 mg per 100g DW. Two QTLs (qcap3.1 and qcap6.1) for capsaicin content were identified on LG3 and LG6, and two QTLs (qhdc2.1 and qdhc2.2) for dihydrocapsaicin content were located on LG2. We did not detect QTLs for total capsaicinoids content. The QTL positions for capsaicin content were different from those for dihydrocapsaicin content. These results indicate that the complexity of selecting for more pungent chilli peppers must be considered in a chilli pepper breeding programme. The QTL‐linked markers identified here will be helpful to develop more pungent pepper varieties from ‘Bhut Jolokia’, a very hot pepper.     

Rare β-Resorcylic Acid Derivatives from a Halophyte-Associated Fungus Colletotrichum gloeosporioides JS0419 and Their Antifungal Activities

Six new β-resorcylic acid derivatives (1–5 and 7) were isolated from a halophyte-associated fungus, Colletotrichum gloeosporioides JS0419, together with four previously reported β-resorcylic acid lactones (RALs). The relative and absolute stereochemistry of 1 was completely established by a combination of spectroscopic data and chemical reactions. The structures of the isolated compounds were elucidated by analysis of HRMS and NMR data. Notably, compounds 1–3 had a β-resorcylic acid harboring a long unesterified aliphatic side chain, whereas the long aliphatic chains were esterified to form macrolactones in 4–9. Among the isolated compounds, monocillin I and radicicol showed potent antifungal activities against Cryptococcus neoformans, comparable to clinically available antifungal agents and radicicol showed weak antifungal activity against Candida albicans. These findings provide insight into the chemical diversity of fungal RAL-type compounds and their pharmacological potential.     

Apo-9′-Fucoxanthinone,Isolated from Sargassum muticum,Inhibits CpG-Induced Inflammatory Response by Attenuating the Mitogen-Activated Protein Kinase Pathway

Sargassum muticum (S. muticum) is a brown edible alga and widely distributed in Korea. This report was designed to evaluate the anti-inflammatory properties of apo-9′-fucoxanthinone (APO-9′) isolated from S. muticum on pro-inflammatory cytokine production. S. muticum extract (SME) exhibited significant inhibitory effects on pro-inflammatory cytokine production in bone marrow-derived macrophages (BMDMs) and dendritic cells (BMDCs). APO-9′ pre-treatment in the CpG DNA-stimulated BMDMs and BMDCs showed a strong dose-dependent inhibitory effect on interleukin (IL)-12 p40, IL-6 and tumor necrosis factor (TNF)-α production with IC₅₀ values ranging from 5.31 to 13.79. It exhibited a strong inhibitory effect on the phosphorylation of ERK1/2 and on activator protein (AP)-1 reporter activity. APO-9′ pre-treatment exhibited significant inhibition of CpG DNA-induced production of inducible nitric oxide synthase. Taken together, these data suggest that SME and APO-9′ have a significant anti-inflammatory property and warrant further studies concerning the potentials of SME and APO-9′ for medicinal use.