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Immunostimulatory effects of dietary poly‐β‐hydroxybutyrate in European sea bass postlarvae 
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下载免费PDF全文 Andrea Franke Catriona Clemmesen Peter De Schryver Linsey Garcia‐Gonzalez Joanna J Miest Olivia Roth 《Aquaculture Research》2017,48(12):5707-5717
The stable production of high‐quality fry in marine aquaculture is still hampered by unpredictable mortality caused by infectious diseases during larval rearing. Consequently, the development of new biocontrol agents is crucial for a viable aquaculture industry. The bacterial energy storage compound poly‐β‐hydroxybutyrate (PHB) has been shown to exhibit beneficial properties on aquatic organisms such as enhanced survival, growth, disease resistance and a controlling effect on the gastrointestinal microbiota. However, the effect of PHB on the developing immune system of fish larvae has so far not been investigated. In this study, the effect of feeding PHB‐enriched Artemia nauplii on survival, growth and immune response in European sea bass (Dicentrarchus labrax) postlarvae was examined. Amorphous PHB was administered to 28‐day‐old sea bass postlarvae over a period of 10 days. The survival and growth performance were monitored, and the expression of 29 genes involved in immunity, growth, metabolism and stress‐response was measured. While the expression of the insulin‐like growth factor 1 (igf1), an indicator of relative growth, was upregulated in response to feeding PHB, the larval survival and growth performance remained unaffected. After 10 days of PHB treatment, the expression of the antimicrobial peptides dicentracin (dic) and hepcidin (hep) as well as mhc class IIa and mhc class IIb was elevated in the PHB fed postlarvae. This indicates that PHB is capable of stimulating the immune system of fish early life stages, which may be the cause of the increased resistance to diseases and robustness observed in previous studies. 相似文献
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Gladys Ludevese‐Pascual Farhana Ahmed Marleen De Troch Edgar Amar Joseph Leopoldo Laranja Samuel Bode Pascal Boeckx Peter Bossier Peter De Schryver 《Journal of the World Aquaculture Society》2021,52(1):184-194
A preliminary study was conducted to demonstrate fate of the bacterial storage compound poly‐β‐hydroxybutyrate (PHB) once ingested and degraded in vivo in crustaceans. The 2% supplementation of 13C‐labeled Ralstonia eutropha DSM545 containing 75% PHB on dry weight in postlarval whiteleg shrimp, Litopenaeus vannamei resulted in consistent enrichment of two fatty acids (containing 14–24 carbons [C] in length ) pentadecanoic acid (15:0) and palmitic acid (16:0) in all lipid fractions. This could indicate that 13C signal may not only originate from the PHB but partly from the structural components of the bacterial cell. There was a trend of lower 13C enrichment in various lipid fractions of the postlarvae as compared to the diet. These findings may have important implications as to potential of PHB as energy source rather than as building block. There was a rapid transfer of 13C in the postlarvae as seen by the significant 13C enrichment in the tissues 4 hr after feeding with labeled bacterial cells. Overall, the assimilation of PHB in crustacean tissues is demonstrated for the first time. Our results indicate that PHB once ingested is rapidly assimilated in the tissues and could probably act as an energy source rather than as a building block. 相似文献
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通过功能互补试验，从慢性型大豆根瘤菌USDA110菌株基因文库中筛选到能互补广宿主根瘤菌NGR234的bdhA突变体菌株NGRPA2和苜蓿根瘤菌的bdhA突变体菌株Rm11107，使之恢复Hbu^ 表型的克隆；经酶活测定的Southern杂交证明该克隆含有bdhA基因。测定了bdhA基因全序列，并在GenBank登记（登记号为：AY077581）。该基因由789个碱基对组成，编码分子量为27.59ku，含262个氨基酸残基的3-羟基丁酸脱氢酶，在该基因的开放阅读框内插入interposonΩKm，并通过同源重组构建了Bradyrhizobium japonicum bdhA突变体（bdhA::ΩKm)。植株试验未显示bdhA基因的突变对结瘤，固痰有明显影响。 相似文献
4.
Jiabao Hu Qiaoqiong Tong Xuanyu Zhou ChongYuan Lin Shanliang Xu Danli Wang Yunlong Zhao 《Aquaculture Research》2019,50(12):3597-3607
Daphnia pulex is considered as a great natural food for aquaculture, and Prohibitin (PHB) is a functional protein that plays a key role in eukaryotic cell activities such as proliferation and ageing. To explore the function of PHB in the ageing process of Daphnia pulex (D. pulex), we cloned and analysed the full‐length cDNA of phb1 and phb2. With the growth of D. pulex, expression of two genes have a N curve trend which raised up first and dropped then raised again. Western blot analysis revealed that expression of the PHB proteins increased from 1‐ to 10‐day age, but did not significantly change from 10‐ to 35‐day age. RNAi knockdown of phb1, reduced expression of phb2 and PHB protein, and significantly induced the expression of sex‐determining related gene Doublesex (Dsx), and ageing‐related pathway gene Protein kinase B (Akt). Longevity of the individuals in RNAi group was shortened to 45 days, which was significantly shorter than the other groups. Despite the growth was not significantly different, reproduction amount was significantly impacted by RNAi. These results suggest that PHB significantly affect ageing of D. pulex and may be involved in the reproductive transformation, leading to a decline of reproductive capacity. This study develops our understanding of the ageing mechanism in D. pulex as a potential model organism, provides further insight into the effect of PHB in the processes of ageing and expands our knowledge of molecular mechanisms on ageing and reproduction. 相似文献
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[目的]以采自海南、广东、广西、福建的含羞草以及云南禄丰南苜蓿中分离的根瘤菌和根际菌为研究对象,从中筛选得到产聚β-羟基丁酸(PHB)菌株227。[方法]主要采用革兰氏染色、苏丹黑染色、16Sr DNA测序等方法。[结果]该菌株的生物学特征为:杆状,大小(0.5~0.9)μm×(1.2~3.0)μm,革兰氏阴性,胞内具PHB颗粒,属于伯克霍尔德氏菌(Burkholderia),同源性达98%。该菌在28℃条件下生长良好,细菌胞内可积累大量的PHB,摇瓶培养40 h后至稳定期,该菌株积累的PHB量可达细胞干重的最大值。[结论]该研究为PHB产生菌提供了菌株资源。 相似文献
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By the study of the influence of COD concentration on denitrifying phosphor removal of A/ASBR (anaerobic/ aerobic sequence bioreactor), it was shown that the favorable treatment effect had been gained with the COD concentration between 220 and 300mg/l; the higher or lower concentration of COD was unfavorable to the work of the system. In our test, it has been confirmed that the rudimental carbon resource organism and cell depositor PHB deposited in anaerobic stage has a significant influence on the process of denitrifying phosphorous removal. The better correlation has been observed also between the consumption of PHB and denitrifying phosphorous removal when the use of cell depositors PHB as carbon resource is concerned. It indicates that the deoxidization of 2 mg nitrate may accelerate the absorption of 1 mg phosphorous. 相似文献
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聚β-羟基丁酸酯(poly-β-hydroxyalkanoates,PHB)是发现最早的一种聚羟基链烷酸酯(polyhydroxyalkanoate,PHA),属于聚酯类化合物。1925年法国学者Lemoigne首次在巨大芽孢杆菌(Bacillus megaterium)细胞中发现分离并提取出了聚β-羟基丁酸酯[1]。聚β-羟基丁酸酯具有热塑性、组织亲和性、光学活性、生物可降解性和生物相容性等多种优良特性,同时还可利用再生资源进行生物合成,在工业、环保、医药等领域有广泛应用[2]。有研究表明,聚β-羟基丁酸酯常在营养不均衡的条件下作为微生物细胞中能量和碳的来源[3]。 相似文献
9.
Liying Sui Yu Liu Huixian Sun Mathieu Wille Peter Bossier Peter De Schryver 《Aquaculture Research》2014,45(3):558-565
Two experiments were conducted regarding the effect of poly‐β‐hydroxybutyrate (PHB) on the survival and development of Chinese mitten crab (Eriocheir sinensis Milne‐Edwards) larvae. Different PHB delivery approaches (particulate, enriched in filter feeding prey, or a combination of both) and feeding levels were applied to crab larvae from the zoea 2 (Z2) up to the megalopa stage. Bio‐encapsulation into rotifers and Artemia at a PHB dose of 100 mg L?1 seemed an efficient approach to deliver PHB to the larvae and resulted in a significantly enhanced survival, development rate and osmotic tolerance. The results indicate that PHB should only be applied as a feed additive rather than as a food source, and that the availability of an adequate amount of nutrients seems to be of major importance for the PHB to induce these beneficial effects. 相似文献
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以平均体质量为(5.66±0.14)g的凡纳滨对虾(Litopenaeus vannamei)为研究对象,分别投喂含聚β-羟基丁酸酯(PHB)质量分数为0%(对照组)、1%、3%和5%的对虾配合饲料,饲养35 d后检测并比较不同水平PHB对凡纳滨对虾肝胰腺免疫和消化指标的影响。结果显示,3%PHB添加组凡纳滨对虾的总抗氧化能力和溶菌酶活性显著高于对照组(P0.05)。Toll基因表达量随PHB含量的升高呈先上升后下降趋势,其中1%和3%PHB添加组的表达量显著高于对照组(P0.05);对照组HSP70基因表达量显著低于其他处理组(P0.05)。5%PHB添加组的淀粉酶、胃蛋白酶和胰蛋白酶活性显著升高(P0.05),而脂肪酶活性无显著变化(P0.05)。由此可见,饲料中添加适量的PHB有利于增强凡纳滨对虾肝胰腺的消化和非特异性免疫能力。 相似文献