摘要：
The effects of the addition of 0–3.0 wt% α-cyclodextrin (α-CD) and γ-cyclodextrin (γ-CD) on the quality of wheat flour as well as the texture and the aging of prebaked bread were evaluated. The addition of α-CD and γ-CD increased the ability of wheat flour to absorb water and shortened the times of dough formation and stabilization. Amylase activity slightly increased after using 2.0 and 3.0 wt% of α-CD and γ-CD, respectively. Moreover, the addition of α-CD and γ-CD increased the fermentation height and gas retention ability of dough. Dough samples containing 2.0 wt% α-CD and 3.0 wt% γ-CD showed the highest fermentation heights and gas retention volumes, respectively. Dough gas production increased with the addition of γ-CD. Gas production by dough samples containing more than 2.0 wt% α-CD exceeded that by samples in the control group. The results of the texture crumb of bread and specific volume tests revealed that the addition of 2.0 wt% α-CD and 3.0 wt% γ-CD reduced bread hardness and increased bread elasticity, resilience, and specific volume. The optimal α-CD and γ-CD contents were identified as 2.0 wt% and 3.0 wt%, respectively. The addition of 2.0 wt% α-CD and 3.0 wt% γ-CD delayed the aging of prebaked bread and reduced the hardness of prebaked bread during different weeks of storage, which may be due to decreasing the melting enthalpy of starch crystals. This work elucidated the mechanisms underlying the effects of CD addition on prebaked bread quality.
摘要：
Yeast cell wall (YCW) preparations are important nutritional additives in the aquaculture industry. Head-kidney macrophages play important roles in innate immune functions in fish. However, the mechanisms underlying their stimulation are not yet characterized. The purpose of this study was to investigate the effects of YCW on immunological functions of channel catfish (Ictalurus punctatus) head-kidney macrophages. Our results showed that YCW preparations not only improved the proliferation and phagocytosis of macrophages but also induced the secretion of reactive oxygen species (ROS), nitric oxide (NO), inducible nitric oxide synthase (iNOS), and cytokines, such as tumor necrosis factor-alpha (TNF-alpha) and interleukin 1 beta (IL-1 beta). At a concentration of 500.0 mu g/mL, YCW preparations stimulated macrophage proliferation and phagocytosis to 1.98 and 1.8 times, respectively, when compared with the negative group. Equally, YCW preparations raised the production of NO by inducing iNOS and ROS in a concentration-dependent manner. Furthermore, these preparations enhanced TNF-alpha and IL-1 beta mRNA levels to multiple digits from 1.2 to 3.0 times, respectively. In conclusion, the stimulatory effects of YCW on the phagocytic activity of the fish macrophages were associated with respiratory bursts coupled with nitric oxide production.
摘要：
A 2-factor test design was used to investigate the effect of an emulsifier (Aldo (R), Lonza, America) (200 g/t) in the diet of Cherry Valley meat ducks to replace some of 2 different oils (animal fat and vegetable oil) on meat production performance, slaughter traits, and fat metabolism. The 900 healthy 18-day-old ducks were grouped into 6 treatments, each with 5 replicates and 30 meat ducks per replicate. The 2 fat sources were established as a positive control group, a negative control group (positive control group-some oil (equivalent to metabolic energy of 50 kcal/ton)), and an emulsifier group (negative control group + 200 g/ton Aldo). The results showed that addition of different fat sources in feed had no significant effect on growth performance, carcass properties, and fat metabolism of 18- to 42-day-old meat ducks (P > 0.05). Reducing the amount of oil used in the feed lowered the growth performance, carcass properties, and affected fat metabolism of meat ducks. However, in feeds with 2 fat sources, some oils were replaced by adding Aldo without affecting growth performance and carcass properties of meat ducks, and improved their fat metabolism, reduced triglycerides (TG) in serum, and increased activity of lipoprotein and hepatic lipases in liver and of pancreatic lipase. Thus, addition of Aldo to a low fat diet could improve growth performance, carcass quality, and lipid metabolism, and promote digestion and absorption of fat for meat ducks.
关键词：
probiotic yeasts;identification and characterization;duck digestive tract
摘要：
The objective of this study was to isolate and identify yeast strains from the digestive tract of ducks, and evaluate in vitro their potential as probiotics in poultry. The yeast strains were isolated using malt extract agar medium, and identified through morphological, physiological, and biochemical tests as well as sequence homology analyses of 26S rDNA D1/D2 region. A total of 35 yeast strains were isolated from the guts of Cherry Valley meat ducks, including seven strains of Saccharomyces cerevisiae (S. cerevisiae). These seven strains of S. cerevisiae were further screened for their use as alternative yeast probiotics strains for poultry feed. The yeast strains were characterized for their cell surface hydrophobicity, autoaggregation ability, and resistance to high temperature (30°C, 37°C, and 42°C), low pH (2.0, 3.0, and 4.0), bile salts (0.3% and 0.6%), and nutrition starvation (2, 4, 6, 8, 10, and 12 days). The isolates of WHY-2 and WHY-7 had a higher survival percentage at 37°C, pH 2.0, 0.60% poultry bile salts, and 10 days of nutrition starvation, with higher cell surface hydrophobicity and autoaggregation, when compared with the other isolates, suggesting that the isolates WHY-2 and WHY-7, could be used as probiotic candidates. The data obtained in this study could help in selecting probiotic yeast candidates for use in poultry industry.
摘要：
Viruses rely on host cellular metabolism for energy and macromolecule synthesis during their replication. Infectious spleen and kidney necrosis virus (ISKNV) causes significant economic losses in the Chinese perch (Siniperca chuatsi) industry worldwide. However, little is known about the relationship between ISKNV replication and cellular metabolism. Using transcriptomic analysis, we observed that glutamine metabolism in Chinese perch brain (CPB) cells is altered during ISKNV infection. Moreover, ISKNV replication was decreased in CPB cells cultured in the glutaminedepleted medium. ISKNV replication was also inhibited in CPB cells cultured in the presence of bis-2-(5-phenylacetamido-1,3,4-thiadiazol-2-yl) ethyl sulfide (an inhibitor of glutaminase), (-)-epigallocatechinmo nogallate (an inhibitor of glutamate dehydrogenase) or L-buthionine sulfoximine (an inhibitor of glutathione synthesis). However, virus replication was rescued by the addition of multiple tricarboxylic acid cycle intermediates, ATP, or glutathione reduced ethyl ester. ATP and reduced glutathione/oxidized glutathione levels were increased in CPB cells infected with ISKNV, but were decreased in CPB cells cultured in glutamine-depleted medium. These results indicate ISKNV infection induces glutaminolysis to accommodate the biosynthetic and energy needs for its efficient virus replication.
摘要：
Cyclophilin A (CypA) is a ubiquitously expressed protein which involves in diverse pathological conditions including infection and inflammation. In this report, a CypA gene (designated as YC-CypA) was cloned from yellow catfish (Pelteobagrus fulvidraco) which is an important cultured fish species in Asian countries. The open reading frame (ORF) of YC-CypA encoded a polypeptide of 164 amino acids with calculated molecular weight of 17.70 kDa. The deduced amino acid sequences of the YC-CypA shared highly conserved structures with CypAs from the other species, indicating that YC-CypA should be a new member of the CypA family. Full-length YC-CypA protein was expressed in Escherichia coli and specific polyclonal antibody against YC-CypA was generated. The YC-CypA protein showed chemotactic activity by transwell migration assay. The mRNA and protein of YC-CypA could be detected in all examined tissues with relatively higher mRNA level in spleen and higher protein level in head kidney, respectively. The temporal expression patterns of YC-CypA, IL-1 beta and TNF-alpha mRNAs were analyzed in the liver, spleen and head kidney post of Edwardsiella ictaluri infection. By immunohistochemistry assay, slight enhancement of YC-CypA protein was observed in the liver, spleen, body kidney and head kidney of yellow catfish infected with E. ictaluri. In conclusion, YC-CypA of yellow catfish showed chemotactic activity in vitro and might have been involved in cytokines secretion in yellow catfish during the infection of E. ictaluri. (C) 2015 Elsevier Ltd. All rights reserved.
摘要：
Infectious spleen and kidney necrosis virus (ISKNV) has caused significant economic losses in the cultured Mandarin fish (Siniperca chuatsi) industry. The molecular mechanisms that underlie the pathogenesis of the viral infection remain poorly understood. In this study, deep RNA sequencing technique was used to analyze the transcriptomic profiles of Mandarin fish brain cells (CPB) at progressive time points after ISKNV infection. A total of 96,206,040 clean data from 98,235,240 sequence reads were obtained. These raw data were assembled into 66,787 unigenes. Among these unigenes, 33,225 and 29,210 had significant hit the Nr and SwissProt databases where they matched 27,537and 19,638 unique protein accessions, respectively. In the samples harvested at 24 or 72 h post of the infection, a total of 10,834 or 7584 genes were differentially expressed in infected CPB cells compared to non-infected cells, including 5445 or 3766 up-regulated genes and 5389 or 3818 down-regulated genes, respectively. In addition, 12 differentially expressed genes (DEGs) were validated by quantitative PCR. These DEGs were involved in many pathways of viral pathogenesis. Further analysis of the major DEGs genes involved in the RLRs and apoptosis pathways revealed some interesting findings. In the RLRs pathway, ISKNV infection inhibited the activation of NF-kappa B via over expression of the IKKB-alpha and IKKB-beta and lessened expression of interleukin-1 receptor-associated kinase 4 (IRAK4). In the apoptosis pathway, ISKNV infection could induce apoptosis mainly via tumor necrosis factor (TNF) mediated extrinsic pathway. The cellular apoptosis induced by ISKNV infection was confirmed using annexinV-FITC/PI and DAPI staining methods. (C) 2015 Elsevier Ltd. All rights reserved.
摘要：
通过在日粮中添加不同水平多糖复合物(mixture of chitosan and saccharicterpenin,MCS),研究其对鲫鱼(Carassius auratus)躯体生化组成、脏器指数及白细胞数目的影响.研究结果表明:3个MCS添加组水分含量、粗蛋白含量较空白对照组有所降低(P＞0.05),但粗脂肪含量则有不同程度增加(P＞0.05);3个MCS添加组灰分含量均低于空白对照组,且0.25%MCS组显著低于空白对照组(P＜0.05);各组间钙、磷含量无显著差异(P＞0.05).添加不同水平的MCS对鲫鱼脏体比、肝胰脏指数和胆指数均具有不同程度的降低作用,其中0.50%MCS组脏体比极显著(P＜0.01)、肝胰脏指数显著(P＜0.05)低于空白对照组;3个MCS添加组胆指数均极显著低于空白对照组(P＜0.01),1.00%MCS组胆指数也显著低于0.25%MCS组(P＜0.05),且随MCS添加量的增加胆指数呈现下降趋势;各组间头肾指数、脾脏指数差异不显著(P＞0.05).各组间血液白细胞数目差异不显著(P＞0.05).
