Optimization of mixed fermentation technology of Lactobacillus helveticus andLactobacillus rhamnosus based on high viable count

以瑞士乳杆菌和鼠李糖乳杆菌混合发酵培养,利用两菌株细胞代谢的差异,以静置发酵24 h后得到的活菌数目为指标,通过单因素实验和正交实验,研究了瑞士乳杆菌和鼠李糖乳杆菌高活菌数混合发酵的最适发酵条件。结果表明,瑞士乳杆菌和鼠李糖乳杆菌高活菌数混合发酵的最优条件为:发酵温度37℃,初始pH=6.8,接种量6%,瑞士乳杆菌:鼠李糖乳杆菌=1∶2,瑞士乳杆菌优先接种3 h。最终得到乳酸菌总活菌数为7.2×10~9m L~(-1)。与在相同条件下单独发酵的瑞士乳杆菌和鼠李糖乳杆菌活菌数相比,分别提高了1∶8倍和10.2倍。为乳酸菌的高活菌数发酵奠定了基础

Characteristics of macrobenthic communities in the estuary of Dagujia River and its adjacent water areas in Yantai, Shandong

为了解烟台大沽夹河河口及邻近海域大型底栖动物群落特征及受干扰情况,于2012年9月在上述区域设置12个采样点进行大型底栖动物群落调查和分析。对采集的生物样品进行物种鉴定、计数和称重,利用生物统计软件PRIMER计算优势度指数(Y)、Shannon-Wiener多样性指数(H')、Margalef丰富度指数(D)和Pielou均匀度指数(J),并进行等级聚类(CLUSTER)、非度量多维标度排序(non-metric multi-dimensional scaling,MDS)及丰度/生物量曲线(abundance and biomass curves,ABC)分析。共采集和鉴定大型底栖动物89..

Long-Term Trends of Macrobenthos in Southern Bohai Sea, China, in Relation toEnvironmental Changes

根据50多年来渤海南部海域大型底栖动物群落的历史资料,以及2011~2013年的现场调查数据,从渤海南部包括黄河口邻近海域及莱州湾大型底栖动物群落结构变化特征出发,分析了其长期演变的过程和规律,旨在阐明底栖动物群落的演变趋势,识别其重要的演变时段.并结合50年来渤海南部海域相关底栖环境因子的变化特征,探讨底栖动物群落的演变原因.过去50余年来,渤海南部海域大型底栖动物群落在物种数、生物量、丰度以及群落结构组成等方面都发生了较大的变动,具体表现为寿命长、体积大、具有高竞争力的K对策种的优势地位正逐渐丧失,而被寿命短、适应能力宽、具有高繁殖能力的R对策种所取代.按照50余年来渤海南部海域大型底栖动..

酸雨胁迫及稀土农用条件下菠菜及其土壤中稀土元素的赋存

利用盆栽实验研究了酸雨胁迫、稀土农用条件下 ,菠菜及其土壤中稀土元素的含量及分布特征。结果表明 :菠菜地上部分的REE含量为 0 .5 2 7～ 0 .696μg·g- 1 之间 ,地下部 2 .668～ 3 .0 0 3 μg·g- 1 。土壤 2 2 9.0 9～ 2 5 0 .3 μg·g- 1 。酸雨明显地影响作物对REE的吸收和利用 ,酸度越大 ,影响越明显。随着酸雨酸度的增大、植株体内、土壤中的REE受淋洗的作用加强而表现出REE的总量随着pH的减小而逐渐减少。施用稀土后 ,植株的地上或地下部分及其土壤中的REE含量均与对照的土壤中的REE分配模式基本相同 ,遵循稀土元素分布丰度的奇偶 (Oddo Harkins)规则、轻稀土富集 ,Eu弱负异常 ,富铈配分型 ,表明稀土元素仍然主要来自土壤并受其影响

Geographic patterns of endemic seed plant genera diversity in China

通讯作者 Author for correspondence. E-mail: [email protected][中文文摘]生物特有现象的地理格局及其形成机制是生物地理学的重要研究内容。本文通过整合173个地区的中国种子植物特有属编目资料、环境和空间因子数据,运用多元回归和方差分解的方法,探索了中国种子植物特有属丰富度及其占全部种子植物属丰富度的比例(特有属比例)与环境(生境异质性和气候)和空间因子的关系。结果表明:(1)特有属丰富度及特有属比例具有很强的空间变异性,在华中地区最高,而靠近国界和大陆边缘的地区较低;相比而言,种子植物属丰富度的空间变异性较弱,且表现出显著的纬度梯度性;(2)特有属丰富度及特有属比例主要由空间因子和生境异质性(地形的复杂性)决定,即在大的空间尺度上,地理位置决定一个地区特有属比例的理论值,生境异质性和气候因子对其进行微调;而种子植物属丰富度的地理格局主要受气候和生境异质性的影响。(3)中国种子植物特有属是主观性非常强的概念,特有属比例所反映的植物区系系统发育信息可能会很低;空间因子所解释的方差中到底有多少是系统发育因素,还需要进一步的研究。本文最后讨论了当前特有属定义和判定的不足之处。虽然理论上认为特有属的判定不应以行政边界为标准,但是目前几乎所有的中国特有属划分方法均以国界为准,这在一定程度上降低了中国种子植物特有属概念的科学内涵和在实践中的作用。因此,我们建议在理论和实践中对中国种子植物特有属概念采取审慎的态度。[英文文摘]Endemism describes the phenomenon that the distribution of individual species/taxa is critically restricted to a specific region.Seed plant genera endemic to China(endemic genera) are those with their main geographic distribution range within the borders of China.The geographic patterns of endemic genera can not only guide conservation planning,but these organisms are also important biological resources.We gathered data of 173 localities on environmental and spatial factors,and regional seed plant genera richness(GRN),endemic genera richness(EGRN) and endemic genera ratio(EGR),which was calculated by dividing EGRN by GRN.Multiple regression and variance partitioning were used to examine how environmental and spatial variables affect GRN,EGRN,and EGR.Our results showed that:(1) EGRN and EGR had stronger spatial variability than GRN,with highest values(richness and ratio) in central China and lower near national borders and continental edges.GRN exhibited an evident latitudinal gradient.(2) EGRN and EGR were mainly determined by habitat heterogeneity and spatial factors.Regional theoretical EGR was constrained by its geographical location,and was further adjusted by habitat heterogeneity(topographical complexity) and climatic factors.Geographical patterns of GRN,on the other hand,were mainly determined by climatic conditions and habitat heterogeneity rather than spatial factors.(3) Seed plant genera endemic to China could be rather difficult to define,and probably reflected inadequate information on phylogenetic evolution of local flora.Further studies are needed to examine the variance explained by spatial factors through a phylogenetic lense.Finally,flaws in the definition and classification of seed plant genera endemic to China were discussed.Theoretically,genera endemic to China should not be defined according to the political borders.But,in practice,nearly all the lists of seed plant genera endemic to China proposed by several authors were based on the relationship between the geographic distribution of specific genus and national borders.Thus,we recommend that,the concept of seed plant genera endemic to China should be used carefully in both theoretical research and biodiversity conservation practices.国家重点基础研究发展计划(973)项目(2009CB421105);国家科技支撑计划项目(2006BAC08B04

Tissue Culture Technique of Acacia mangium Elite Trees

作者简介: 黄烈健( 1971—) ，男,博士,副研究员,研究方向为林木遗传育种与森林培育，电话: 020-87033463,E-mail: hlj@ ritf.ac.cnTaking Acacia mangium elite trees as explants，the tissue culture technique system for dormant bud of 3-5 year-old elite trees was established． The system includes the germination-inducing of the dormant buds，the multiplying of shoots，the rooting of adventitious shoots，and the pre-treating and transplanting of seedlings． The medium MS + Sucrose 30 g·L－1 + BA 0.5 mg·L－1 + NAA 0.1 mg·L－1 was used for inducing the dormant buds; the medium MS + BA 1.0 mg·L－1 + NAA 0.05 mg·L－1 was used for multiplying; while the medium 1 /2 MS +IBA 2.0 mg·L－1 + NAA 0.5 mg·L－1 was used for rooting.The results revealed that it was viable to producing field seedlings with micropropagation.Although the branches with dormant buds harbored many kinds of microbes and the adventitious shoots were not easy to root，20% to 30% healthy germination could be yielded and the rooting rate of adventitious shoots could be higher than 85%.Pretreated with ABT powder ( rooting hormone) ，both the rooting rate and survival rate of adventitious shoots were nearly 100%．国家“十一五”科技支撑计划项目(2006BAD01A15-5,2006BAD32B010-3); 农业科技成果转化项目(2009GB24320482

p38MAPK induces apoptosis of glioma cell

目的　研究 p38MAPK基因转染大鼠胶质瘤细胞系C6后对其生物学特性的影响 .方法　利用脂质体介导法将p38MAPK基因导入大鼠胶质瘤细胞系 C6中 ,用免疫细胞化学染色检测其在细胞转染前后的表达情况 ,用 HE染色、流式细胞仪等方法研究其对细胞形态、粘着状况和生长周期的影响 .结果　转染 p CMV5 - p38MAPK质粒组 p38MAPK蛋白表达阳性 ,细胞形态发生变化 ,贴壁性降低 ,出现大量凋亡细胞 .结论　转染 p38MAPK基因可诱导胶质瘤细胞凋

ECFA之后的两岸政治关系走向

在两岸政治互信和良性互动逐渐增强、两岸全面交流局面形成、两岸顺利签署ECFA的大背景下,两岸关系和平发展如何向深度和广度推进,特别是如何发展两岸政治关系?成为两岸有识之士普遍关注的话题。两岸著名专家学者发表看法

The Role of Microorganisms in the Geochemical Iron Cycle

铁元素虽然只在地壳含量中位列第4,但却是地球上分布最广的变价金属元素之一,微生物介导的铁循环及其与生源要素碳、氮、氧和硫等耦合的氧化还原反应是微生物地球化学循环的重要驱动力.由于铁循环过程中氧化态三价铁Fe(Ⅲ)在环境p H条件下大多以不溶状态存在,因而由其参与的地球化学循环进程通常较为缓慢.研究表明,微生物在铁元素的地球化学循环过程中起着举足轻重的作用,并在该过程中参与矿物的生成与转化.近年来的最新研究发现,参与地球化学铁循环的微生物之间,微生物与矿物之间,以及矿物介导的微生物之间存在着多样的相互作用,而含铁矿物介导的微生物胞外电子传递机制是其中最受瞩目的研究热点.本文综述了微生物介导的地球..

Species composition and ecological distribution of planktonic diatoms in the Changjiang River estuary during Spring

20 0 2年春季 ,在长江口附近海域典型赤潮高发区 2 8个大面站位采集了 5 3个样品 ,从中共鉴定出隶属于 31个硅藻属的 80个种和变种 ;其中种类多样性较高的属为圆筛藻属 (Coscinodiscus) ,有 17个种 ,斜纹藻属 (Pleurosigma) ,有 8个种和变种 ;数量上较优势的种为柔弱拟菱形藻 (Pseudo nitzschiadeli catissma) ,为 3.4 8× 10 3 cells·L-1,占 2 8.5 4 % ;具槽直链藻 (Melosirasulcata) ,为 1.4 3× 10 3 cells·L-1,占16 .98% ;尖刺拟菱形藻 (Pseudo nitzschiapungens) ,为 0 .71× 10 3 cells·L-1,占 9.85 % .它们在大部分站位中都有出现 ;柔弱拟菱形藻和尖刺拟菱形藻的高细胞密度区主要出现在 12 30E断面的站位 ,而具槽直链藻则主要出现在长江口的 31～ 32°N断面的站位 .浮游硅藻总细胞丰度变化于 0 .4 3× 10 3 ～ 2 3.3× 10 3 cells·L-1,平均 4 .6 1× 10 3 c... 【英文摘要】 water samples were collected from 28 stations in typical regions where redtide frequently occurred in the Changjiang River estuary during Spring, 2002. In total, 80 diatom species and varieties belonging to 31 genera were identified, among which, genera with high species biodiversity included Coscinodiscus which contained 17 species and Pleurosigma which contained 8 species and varieties. Quantitative analysis of diatom cell density showed that Pseudo-nitzschia delicatissma (3.48×10 3cells·L -1, 28.54%...国家重点基础研究发展规划资助项目 ( 2 0 0 1CB40 970 1)