三种酶制备牡蛎蛋白水解物的抗氧化活性和功能特性分析

目的：比较分析木瓜蛋白酶、胃蛋白酶和胰蛋白酶三种不同酶水解牡蛎获得的蛋白产物抗氧化活性和功能特性。方法：采用木瓜蛋白酶、胃蛋白酶和胰蛋白酶三种不同酶水解牡蛎蛋白获得水解物,并分别测定它们的在不同pH下的溶解度、乳化性以及不同浓度水解物的还原能力、DPPH自由基清除率和Fe^{2 +}螯合能力。结果：表明三种酶水解物都有较高的溶解度(p＜0.01),胰蛋白酶产生的水解物溶解高度达94.8％(p＜0.05)；水解物溶解度和乳化活性指数在pH4显著降低(p＜0.05)。牡蛎蛋白质水解产物的还原能力、DPPH自由基清除能力和金属螯合活性随浓度的增加而增强,其中胰蛋白酶和胃蛋白酶抗氧化能力较强(p＜0.01)。结论：三种蛋白酶水解牡蛎蛋白可获得抗氧化活性强、溶解度高的水解物,并受浓度和pH的影响,它们的水解物可作为一种潜在的抗氧化功能多肽利用。     

云南省食用菌产业技术标准体系建设研究

分析了食用菌标准化现状，归纳目前食用菌标准体系存在的主要问题，提出云南省食用菌标准体系建设的原则与依据，按照产前、产中、产后划分标准类别，构建云南省食用菌产业技术标准体系。     

Design and performance of a recirculating aquaculture system for oyster larval culture

The major objective of this study was to introduce a newly designed recirculating aquaculture system (RAS) for oyster (Crassostrea angulata) larval culture. The system includes a culture tank, a suspended circular inlet‐pipe, an upwelling aeration pipe, combined “banjo” sieves and a bioreactor chamber containing microalgae life keeping installation. The system was designed to resolve three problems: (i) stranding of larvae caused by water level changes and aeration, (ii) physical clogging of the screens and also (iii) deterioration of diet microalgae. The culture tank, “banjo” sieve size, water flow rate and light intensity for maintaining microalgae activity were all designed according to the pattern of larval movement and feeding behaviour. Results of this study showed the best average SGR for larval length was 6.36%/d (9.5 μm/d) and survival rate was 80%, with initial rearing density of 50 larvae/ml, indicating the problems above were fully resolved. Consequently, the system is fit for larval culture in mass production of oysters.     

基于病毒宏基因组技术侦测牡蛎体内病毒

建立了牡蛎(Crassostrea spp.)病毒宏基因组研究方法,应用差速离心和蔗糖垫超速离心提取病毒样颗粒,核酸酶处理宿主游离核酸后提取病毒总核酸,经反转录、双链合成和核酸扩增获得足量DNA。高通量测序共获得1 661 809 000个碱基,包括6 647 236个读长(reads)信息,拼接后得到50 842个重叠群(contig),序列总长度达到14 239 389 bp。同时从reads质控图等多方面对测序数据进行分析与评估,显示测序数据质量良好。数据与病毒库进行比对,发现病毒序列来自于小核糖核酸病毒科(Picornaviridae)和疱疹病毒科(Herpesviridae)2个科,类单纯疱疹病毒(Simplexvirus)、心病毒(Cardiovirus)和肠道病毒(Enterovirus)3个病毒属。     

Phenotypic indicators for cultured pearl size improvement in the black‐lipped pearl oyster (Pinctada margaritifera): towards selection for the recipient growth performance

The black‐lipped pearl oyster, Pinctada margaritifera, is the most important farmed species in French Polynesia and the basis of the most valuable export industry. Mass production of black pearls relies on a surgical operation requiring tissue from a donor pearl oyster to be grafted, together with a nucleus made of shell, into the gonad of a recipient oyster. Improving pearl size through family selection remains one of the main challenges for future aquaculture development. This study analyses the relative contribution of donor and recipient oysters to pearl size. To this end, hatchery‐produced donor oysters of two batches, large and small (based on shell height), were used to supply grafts for recipients, which were then monitored individually for their growth performance by recording shell height, width, and thickness, and total live weight (flesh + shells) every 6 months (four biometric measurement times) over 20 months of culture. Pearls issued from the two batches of donors showed no significant differences in nacre weight or thickness. In contrast, recipient oyster shell height and total weight were increasingly positively correlated with these pearl size parameters over the culture period, becoming significant at 8 months post‐grafting. Potential therefore exists to use shell height and oyster weight as phenotypic indicators for selective breeding of recipient oysters with high growth performance to increase pearl size in P. margaritifera.     

牡蛎蛋白饮料色泽形成机理初探

通过比较不同贮藏温度（4、20和37 ℃）条件下不同pH值(pH 4.9组和pH 6.7组)的牡蛎蛋白饮料在杀菌及贮藏期间褐变指数、游离氨基酸、总糖和还原糖浓度以及pH值的变化,初步探讨饮料中色泽形成的机理,为牡蛎蛋白饮料加工提供科学理论依据。试验结果显示,两组饮料的褐变指数在杀菌及贮藏过程中均有明显的上升趋势,但是pH 6.7组的褐变指数总体明显高于pH 4.9组,另外褐变指数总体与贮藏温度呈正相关。成分分析结果显示,两组饮料在贮藏过程中成分变化的规律基本一致,但是pH 6.7组各成分变化的幅度较pH 4.9组大。其中,天门冬氨酸等部分氨基酸呈明显上升趋势,而精氨酸、苏氨酸、丝氨酸、半胱氨酸、酪氨酸等氨基酸以及还原糖呈明显下降趋势。从以上结果可以推测,精氨酸、苏氨酸、丝氨酸、半胱氨酸和酪氨酸等氨基酸以及还原糖是牡蛎饮料非酶褐变反应的主要因子,温度和pH是牡蛎饮料发生褐变反应的重要条件,高温和高pH值可以促进牡蛎饮料褐变反应的发生。     

Trichoderma species associated with green mould disease of Pleurotus ostreatus and their sensitivity to prochloraz

Green mould disease causes serious economic losses in Pleurotus ostreatus crops worldwide, including in Italy, where prochloraz is the only chemical fungicide allowed to control the disease. The effectiveness of the doses 0.01, 0.05, 0.25 and 1.25 μL L⁻¹ (field dose) of prochloraz (Sponix Flow, 450 g L⁻¹), against colony growth rate and spore germination of Trichoderma pleuroti, T. pleuroticola and T. guizhouense strains on wheat straw extract agar plates were evaluated. Complete inhibition of Trichoderma pleuroti and T. pleuroticola growth was shown by the field dose of prochloraz, and also by the 0.25 μL L⁻¹ dose for T. pleuroti. Complete inhibition of spore germination occurred for all Trichoderma strains at field dose, and at 0.25 μL L⁻¹ for T. pleuroti strains. In in vivo assays, the effect of prochloraz doses 0.05, 0.25 and 1.25 μL L⁻¹ on colonization of straw substrate by T. pleuroti, T. pleuroticola and T. guizhouense inoculated at two spore densities (10² and 10⁵ spores mL⁻¹) immediately after P. ostreatus spawn was studied. Trichoderma pleuroti and T. pleuroticola were both responsible for green mould disease, whereas T. guizhouense was not pathogenic. Trichoderma pleuroti was more aggressive than T. pleuroticola. Prochloraz was effective against T. pleuroti at the field dose, and against T. pleuroticola at 0.25 and 1.25 μL L⁻¹. The study on Trichoderma × Pleurotus interaction type showed that Trichoderma species were active against the mycelial growth of P. ostreatus by competition for space and nutrients, and neither hyphal interaction nor effect by volatile or nonvolatile metabolites occurred.     

北海珍珠养殖区与非养殖区春、秋季磷的形态特征及其相关性

利用2008年9月和2009年4月对北海珍珠养殖区和非养殖区的调查资料,对该海区磷的循环特征及其生态效应进行了分析研究.研究结果表明,该海区磷的储量不高,无论是养殖区还是非养殖区均表现为有机态磷和无机磷含量明显偏低.除颗粒态磷外,所有形态磷均表现为秋季明显高于春季,突出体现了生物释放的补充影响作用.在磷的形态转化上,春...     

平菇栽培料中添加胡萝卜樱试验

以生产上常用配方为对照,在平菇栽培料中添加2％～6％的胡萝卜樱,以菌丝长速、子实体产量等为指标进行对比,研究平菇生产中胡萝卜樱的最佳添加比例.结果表明:在平菇生产中,可以添加2％～6％胡萝卜樱,其中添加4％效果最好,生产上应重点推广使用;处理2(胡萝卜樱添加量2％)、处理4(胡萝卜樱添加量6％)和处理1 (CK)差异不显著;处理3(胡萝卜樱添加量4％),菌丝长速指标显著高于处理1 (CK).