液态发酵大豆抗氧化活性肽条件的优化

筛选和优化液态发酵法生产大豆抗氧化活性肽的条件.以总抗氧化活性的强弱为指标,通过对发酵温度、种龄、pH值、接种量、料液比、发酵时间等条件作单因素、析因试验确定主要影响因素,并采用最速上升试验和中心组合二次旋转回归响应面法优化pH值、接种量.优化获得液态发酵大豆抗氧化活性肽的最佳工艺参数为发酵温度37℃,种龄36 h、pH值为7.39,接种量为5.19%,料液比4%,发酵时间36 h.在此条件下发酵产物总抗氧化活性795.75 U·g-1(豆粕),试验值与预测值基本相符.     

酒曲生料发酵制胶废水生产单细胞蛋白

应用正交试验设计法,以制胶废水为主要原料,选用酒曲为菌种来源进行生料发酵生产单细胞蛋白。通过对乳清摇瓶发酵条件包括糖含量、培养时间、接种量的优化,以便在最佳的发酵条件下获取最多的单细胞蛋白。结果表明,发酵的最佳条件为∶糖含量0.08g血L（蔗糖）,接种量2%（酒曲）,培养时间72h。在此条件下,所产的菌体粗蛋白含量为5.16%（w/）,菌体生物量（湿重）为79.20gL,发酵液的pH为3.8,其发酵液可作为生物凝固剂凝固胶乳,减少凝固用酸的量。     

蛋白酶对大豆蛋白和花生蛋白溶解性的影响

为了改善醇法大豆浓缩蛋白和花生粕的溶解性,利用Alcalase碱性蛋白酶和Validase FPconcentrate蛋白酶对它们进行限制性水解。结果表明,利用Alcalase碱性蛋白酶水解醇法大豆浓缩蛋白的最佳水解条件为:温度50℃、pH 8.0、水解时间3 h,底物浓度为10%,酶浓度为0.5%(占底物),在此水解条件下醇法大豆浓缩蛋白的氮溶解性指数(NSI)由4.37%提高到60.34%,水解度为6.37%。利用Validase FP concentrate蛋白酶对花生粕进行水解时的最佳水解条件为:温度50℃、pH 7.0、水解时间4 h,底物浓度10%,酶浓度1%(占底物),在此水解条件下花生粕的氮溶解性指数(NSI)由42.40%提高到87.54%,水解度为12.90%。     

木瓜蛋白酶水解大豆浓缩蛋白实验研究

采用木瓜蛋白酶对大豆浓缩蛋白进行酶水解改性,通过氮溶解指数(NSI)的测定确定水解的有效性。实验表明,木瓜蛋白酶对大豆浓缩蛋白产生了有限水解,对大豆浓缩蛋白的功能特性有一定影响。通过L9(34)实验确定了最佳水解条件是:酶浓度为7000u/g、温度为65℃、pH为6·5、反应时间为2h、底物浓度为5·5%。     

影响大豆乳清蛋白起泡性因素研究

大豆乳清蛋白是一种天然两亲物质,具有界面性质,是一种天然的表面活性剂.易消化吸收、具有很高的代谢效率和生物学价值.以蛋白质溶液的浓度、温度、离子强度、震荡时间等作为影响因素,通过实验得出结论大豆乳清蛋白起泡性效果最佳条件是:浓度1.0%,温度60℃,pH值5,钙离子强度0.1 mol/L.     

大豆乳清废水超滤条件研究

就超滤溶液pH、操作压力、操作温度等操作参数对大豆乳清蛋白超滤过程的影响进行了研究,通过单因素试验和3因素3水平正交试验,确定了比较合适的超滤条件:超滤压力选择0.025MPa,超滤pH选择8.0,超滤温度选择30℃。在此条件下,蛋白质的截留率为80.44%。     

五指山绿茶酒的研制

以五指山绿茶为原料,研究绿茶汁的浸提工艺和绿茶酒的发酵工艺。通过单因素试验,确定最佳浸提条件为：茶水比1∶70(g/mL),浸提温度85℃,浸提10 min,所得的茶汁感官品质良好。通过正交实验优化得到绿茶酒的最佳发酵工艺条件为：酵母接种量0.05%,蔗糖添加量190 g/L,初始pH值4.0,发酵温度28℃。在此条件下生产的绿茶酒色泽黄绿透明;酒香淡雅,茶香怡人;酒体丰满,酸甜适口;具有本品独特的风格。     

Protex7L中性蛋白酶改性大豆分离蛋白的工艺研究

利用中性蛋白酶Protex 7L对大豆分离蛋白进行改性研究,以水解度和蛋白质分散指数为评价指标,确定了中性蛋白酶Protex 7L改性大豆分离蛋白的最佳酶解反应条件:加酶量13.5AU/g大豆分离蛋白(SPI)、反应温度55℃、底物浓度为10%、pH值为7.0,酶解时间为1h.在上述条件下大豆分离蛋白的分散性得到显著改善,蛋白质分散指数(PDI值)达到91.8%.     

响应面法优化复合菌种发酵豆粕条件

以豆粕、麸皮、糖蜜为原料,利用米曲霉和酿酒酵母混菌发酵生产高蛋白饲料。通过单因素试验研究了菌液接种量、温度、发酵时间、料水比、麸皮添加量、糖蜜添加量对粗蛋白含量的影响。在此基础上进行响应面优化,得出最佳发酵工艺条件:装料量25 g(其中91%豆粕、7%麸皮、2%糖蜜),1.5%MgSO_4,1%(NH_4)_2SO_4,1%尿素,1%K_2HPO_4,料水比1∶1.1,接种13%的菌液,在31.3℃发酵78.6 h。在最佳发酵条件下,粗蛋白含量达到56%,比发酵前提高13.96%;真蛋白含量达到52.43%,比发酵前提高21.39%;活菌数达到1.38×109;脲酶活性降低了95.93%。该复合菌株发酵模式可以有效提高产品的蛋白含量,降低脲酶活性,降解大分子蛋白质和抗原蛋白,且发酵过程中产生曲香味和酒香味,适用于豆粕发酵的工业化生产。     

响应面优化豆粕生物肽的生产工艺研究

以高温豆粕为原料,枯草芽孢杆菌为试验菌株,在单因素试验基础上,以发酵液a-N含量为响应值,对摇瓶发酵制备大豆肽工艺条件进行响应面优化.确定最佳工艺条件为:豆粕粒度40目,初始pH 6.8,种子培养时间16.25 h,碳源用量1.75％,豆粕用量10.75％,接种量6.25％,发酵时间48 h.在此条件下,发酵液α-N含...     

Analysis of nutritional components of eight famine foods of the Republic of Niger

In the western Sahel, indigenous plants become important staples when cereal harvests are inadequate to support populations inhabiting that region of Africa. The purpose of this study was to assess the nutrient content of several of these edible wild plants. The leaves of the following seven plant foods were analyzed: Ziziphus mauritiana, Cerathotheca sesamoides, Moringa oleifera, Leptadenia hastata, Hibiscus sabdarifa, Amaranthus viridi, and Adansonia digitata. The fatty acid, vitamin E, carotenoid, selected mineral and amino acid contents of these plant foods were determined. These same analyses were performed on the fruit of the Adansonia digitata. In quantitative and qualitative terms, Amaranthus viridis was found to be an excellent source of protein. Its amino acid composition compared favorably to that of a World Health Organization (WHO) protein standard. It also contained considerable amounts of the two fatty acids that are essential in humans (linoleic and -linolenic) and a number of minerals including iron, magnesium, calcium and zinc. The leaves of Hibiscus sabdarifa contained an appreciable quantity of protein the composition of which was comparable to the WHO standard. The mineral content of the leaves of this plant was also exceptionally high; noteworthy was its high zinc content. H. sabdarifa also contained significant quantities of the two essential fatty acids. Ziziphus mauritiana was an excellent source of the essential fatty acid linoleic acid and several of the metals including iron, calcium, magnesium and zinc. Its content of other essential nutrients, however, was rather low. In general, Adansonia digitata leaves were nutritionally superior to the fruit of the tree; however, the fruit did contain useful quantities of potassium, phosphorus, zinc and -linolenic acid. The Leptadenia hastata leaves were an especially good source of lutein and -carotene. These data should be useful to the people who inhabit the western Sahel in helping them devise healthy diets during times when cereal staples are in short supply.     

芦笋枯萎病病原鉴定

对造成福建省漳州市东山县的芦笋枯萎病病原菌进行分子鉴定,以期确定病原菌的属、种名,为防治该病害寻求理论依据。试验对分离纯化的病原菌核糖体DNA的ITS区进行测序,在Genbank中搜索其同源性并构建它们的系统发育树,结果表明：引起芦笋枯萎病的病原菌是镰刀属中的尖孢镰刀菌(Fusarium oxysporum),且病原菌之间的同源性高达89%,遗传差异不显著。     

狗牙根诱变后代抗寒性评价

通过电解质外渗法和匍匐茎恢复试验对‘阳江’狗牙根及其12个通过形态鉴定选出的坪用价值高且花序密度低的诱变后代进行抗寒性鉴定。电解质外渗法结果表明:诱变后代间的抗寒性具有较大差异,其叶片半致死温度(LT₅₀)的变异范围为-7.6～-0.2℃(最低值与最大值相差7.4℃);参试材料抗寒性由强到弱依次为M18>M4>M26>M28> M22>阳江>M29>M31>M10>M37>M16>M1>M25,其中,有5个诱变后代抗寒性优于亲本,分别是M18、M4、M26、M28、M22。匍匐茎恢复实验结果表明:诱变后代M1、M22、M26、M31、M25在0℃和-5℃低温胁迫后的恢复生长率都高于亲本,恢复能力均优于亲本;M10、M37、M28在-5℃低温胁迫下,恢复生长能力低于亲本,抗寒性相对较弱,M16和M4在0℃和-5℃低温胁迫下,恢复生长率都低于亲本,抗寒性明显弱于亲本。综合2种方法鉴定结果显示:诱变后代M1、M25的恢复能力较强;M4、M28的叶片抗寒性较好,青绿期较长;M22、M18、M26的叶片抗寒性和匍匐茎恢复能力均较强;M29,M31的叶片抗寒性和匍匐茎恢复能力与亲本相似;M10、M16、M37的叶片抗寒性和匍匐茎恢复能力均较弱,整体抗寒性较弱。     

玉米产量性状配合力遗传分析

通过对8个中晚熟玉米自交系产量性状进行双列杂交分析，表明各个自交系产量性状的一般配合力与特殊配合力存在显著差异，玉米杂交种F₁的产量构成受到一般配合力与特殊配合力的共同作用，用特殊配合力对F₁的作用大于一般配合力。特殊配合力高低与一般配合力无明显相关关系。因此在玉米杂交种组配与自交系改良工作中，既要兼顾双亲的一般配合力与特殊配合力，又要保持杂交优势利用模式与选系模式的种质关系。     

Mechanism of action of insecticidal secondary metabolites of plant origin

Insect pest management is facing the economic and ecological challenge worldwide due to the human and environmental hazards caused by majority of the synthetic pesticide chemicals. Identification of novel effective insecticidal compounds is essential to combat increasing resistance rates. Botanicals containing active insecticidal phytochemicals appear to be promising to address some of these problems. Therefore, there is a continuous need to explore new active molecules with different mechanisms of action. Secondary metabolites present in plants apparently function as defense (toxic), which inhibits reproduction and other processes. The phytochemical biomolecules could be used for maximizing the effectiveness and specificity in future insecticide design with specific or multiple target sites, while ensuring the economic and ecological sustainability. In this article, the current state of knowledge on phytochemical sources and insecticidal activity, their mechanism of action in insects, resistance, and promising advances made in phytochemical research are reviewed.     

马铃薯黑痣病菌生物学特性测定

马铃薯黑痣病是土传真菌性病害,在定西市马铃薯种植区均有发生,目前已成为影响马铃薯产量和品质的主要因素之一。本研究对马铃薯黑痣病菌从温度、光照、碳源、氮源以及p H方面进行了生物学特性的测定。结果表明:该病原菌菌丝在无光25℃条件下生长最快,在无光35℃条件下生长最慢;室温条件下培养1 d后用紫外线照射处理2 h,然后室温持续光照培养4 d的菌丝生长速率最大,持续黑暗培养4 d的菌丝生长速率最慢;不同碳氮源对该菌菌丝生长均有影响,碳源为淀粉的培养基上菌丝生长最快、氮源为尿素的培养基上菌丝生长最快;培养基p H中性时菌丝生长速率最大。     

橡胶树丛枝病病原的抗血清制备与应用

以感染橡胶树丛枝病病原的长春花为材料,制备得到橡胶丛枝病病原菌抽提液,以抽提液为抗原免疫家兔,制备抗血清,经微量沉淀测定,抗血清效价为１：２０４８。应用橡胶丛枝病抗血清检测橡胶褐皮病,无症苗木检出率达３０％－３７％,可疑的褐皮病树检出率达８５．７％。     

Valorization of three varieties of grape

In the present investigation, seed methanolic extracts of three Vitis vinifera (Muscat d’Italie, Syrah and Carignan) were assayed for their antioxidant activities. Results showed that there are strong variations in the contents of total phenols (440.97–121.94 mg GAE g⁻¹ DW), flavonoids (48.07–16.81 mg EC g⁻¹ DW) and tanins (37.15–14.9 mg EC g⁻¹ DW) from the studied seeds. The phenolic composition of these extracts was determined by RP–HPLC after acid hydrolysis. The main phenolic compound was quercetin with 27.2% in Muscat d’Italie, 48.8% in Syrah and 28.4% in Carignan. Besides, all seed extracts showed remarkable DPPH radical scavenging activity with IC₅₀ values ranged from 1.8 to 30 μg ml⁻¹. EC₅₀ values of reducing power activity ranged from 100 to 120 μg ml⁻¹. The high phenolic content and the considerable antioxidant activities of vitis seed extracts could potentially be considered as an expensive source of natural antioxidants.     

几个粳稻不育系、恢复系产量性状配合力研究

新粳型不育系和恢复系是通过籼粳交或粳粳交的方式培育而成的中间型稳定品系,杂交组合的育性正常或接近正常。粳型不育系和恢复系配组,杂种F1的产量性状差异显著或极显著。组合9512A/R364、73A/R55、150A/R198、9512A/R2690、150A/R55,具有产量的正向超亲、超标优势,另一些组合呈显著或极显著的负向优势;本研究产量性状一般配合力好的不育系是中14A、辽150A、73A、9512A、9214A,恢复系是R198-2、R238、R46、C418、R364和花38;亲本的产量性状一般配合力和特殊配合力在不同性状的作用没有交叉。杂种优势的表现与双亲亲和力高低、配合力高低有明显的相关性。辽150A、9512A的超亲优势明显,R198、R55、R2690、R364、C204等恢复系具有较强的杂交优势。不育系对产量性状的作用显著大于恢复系。     

Size and frequency of occurrence of pre-roost gatherings of starlings

One hundred and fifty-six pre-roost gatherings of starlings were observed at 28 sites around a roost in west Norfolk during winter. Pre-roost gatherings occurred more frequently at individual farmyards compared with individual fields, but 82% of the sites where gatherings occurred were on fields. The size of gatherings was greater, the closer to the roost. Birds in pre-roost gatherings on fields of autumn-sown winter wheat spent most of the time feeding and had a diet composed almost exclusively of wheat seeds. Birds in gatherings on grass fields also fed intensively whereas only 31% of birds at farmyards were feeding. The implications that these results have with regard to potential damage to fields of winter wheat and around farmyards are discussed.