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1.
从虾、蟹、蛤等海产品加工业的堆弃物中可以提取10％～30％的有用有机质——甲壳素(Chitin),又名甲壳质,壳多糖。由于其大量存在于低等动物,特别是节肢动物(如虾、蟹、昆虫等)的甲壳中,故俗称甲壳素,国内又称不溶性甲壳质。它是地球上最丰富的有机质之一。据统计,自然界每年由生物合成的甲壳素有数十亿吨之多,是一种十分丰富的再生资源。 相似文献
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甲壳素对Cr(Ⅵ)的吸附研究 总被引：1，自引：0，他引：1
齐春惠 《中国海洋大学学报(自然科学版)》2001,31(5):777-781
采用正交实验法 ,使用甲壳素 (粗制壳聚糖 ) ,研究温度、时间、吸附剂用量、酸度、盐效应对甲壳素吸附水中溶解的 Cr( )离子的吸附过程的影响 ,将实验结果进行极差分析 ,得到较优的吸附条件。实验结果表明 :在 p H =2、30℃、离子强度 5 mmol/ L的条件下 ,甲壳素对 Cr( )的最大吸附量为 13.1mg/ g。根据化学平衡及红外光谱分析结果表明 :甲壳素对 Cr( )的吸附主要是游离氨基静电吸附 Cr2 O2 -7,吸附符合 L angmuir吸附等温式 相似文献
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对虾、蟹等甲壳废弃物中所提取的甲壳素及其衍生物的综合利用做了详细的描述。综述了近几年来，有关甲壳素－壳聚糖的研究概况，并从几个方面阐述了虾、蟹等加工废弃物利用的发展前景和潜在市场。为进一步开发应用提供参考。 相似文献
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本文讨论了用90％丙酮从海藻中提取叶绿素进行测定的三种提取方法(研磨法、浸泡提取法、超声波粉碎法)的最佳条件。并对三种提取方法的提取效率进行了比较。结果表明研磨法的提取效率较高,样品可立即测定,是一种较好的提取方法。 本文还讨论了不同离心力对叶绿素测定的影响。实验表明使用离心力为2000g的[X]—64—01型离心机可基本满足测定要求。 相似文献
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本文讨论了用90％丙酮从海藻中提取叶绿素进行测定的三种提取方法(研磨法、浸泡提取法、超声波粉碎法)的最佳条件。并对三种提取方法的提取效率进行了比较。结果表明研磨法的提取效率较高，样品可立即测定，是一种较好的提取方法。本文还讨论了不同离心力对叶绿素测定的影响。实验表明使用离心力为2000g的LXJ-64-01型离心机可基本满足测定要求。 相似文献
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微藻总脂含量测定方法概述 总被引：1，自引：0，他引：1
概述微藻总脂含量测定方法的研究现状并比较各方法的优缺点:(1)有机溶剂提取法使用较普遍、易操作、成本低,缺点是所需样品量大、所得总脂含量较低、溶剂有毒易污染环境、操作耗时费力;(2)索氏提取法测定微藻总脂含量较准确,缺点是所需试剂和样品量大,提取时间长;(3)荧光染料测定法、傅里叶变换红外光谱法、磷酸香草醛法、铜试剂法、苏丹黑染色法以及核磁共振法所需样品量少、所用时间短,但测定的总脂含量均为相对值.其中,荧光染料测定法不需要提取油脂且灵敏度高,但其易受各种因子影响;傅里叶变换红外光谱法和核磁共振法对样品无损伤,无需或仅需很少的预处理,后者重复性很好;磷酸香草醛法较稳定;铜试剂法成本低,但对其报道极少;苏丹黑染色法操作简单,不需要对藻细胞破碎及化学抽提,但不适用于不均匀样品的测定;(4)超临界CO2提取法和离子液体提取法提取效率高,所得总脂含量较高,但测定成本较高. 相似文献
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海底沉积物的声学声速特性是沉积物声学中的一个重要的研究方向。正确提取声学原位测量的声速对海底沉积物声学反演至关重要。分析了海底声学原位测试系统的输出子波特性,提出了基于子波提取的互相关双向极值声速提取法。在声速提取过程中,发现某些通道实测声波到达时会出现超出正常范围的异常。分析后认为异常通道的到达波相位出现180°反至现象。通过互相关数值的负极小值提取的声波到达时对互相关正极大值所获得的到达时曲线进行校正后提取声速,得到了正确的结果,说明了本方法的正确性。 相似文献
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在陆架海区沉积物中, DNA高通量测序技术可检获大量浮游寡毛类和舞毛类等非底栖纤毛虫,这些源于水体的环境DNA(eDNA)如何影响对沉积物中纤毛虫分子多样性的评估,以及影响程度如何尚不明确。本研究选取了黄海冷水团中的两个站位,通过提取水体和沉积物中DNA和RNA,并采用直接提取法和洗脱法提取沉积物DNA,结合DNA和cDNA测序技术,探讨了水体和沉积物中纤毛虫分子多样性的关系。研究表明,基于洗脱DNA法、直接提取DNA法和cDNA法获得的沉积物中纤毛虫OTUs数分别为451、312和324个,其中211个OTUs同时由三种方法检获;而164个OTUs仅通过洗脱DNA法检获,其中89%为相对丰度低于0.1%的稀有类群。直接提取DNA法所获的寡毛类和舞毛类序列数占比达46%,而在洗脱DNA法和cDNA法中占比仅为12%和10%。沉积物中检获的43%—71%的舞毛类和寡毛类OTUs与浅层水(40m)共有,仅19%—29%与深层水(40m)共有,且这些共有的OTUs可同时在浅层水中检获。本研究发现,对沉积物中纤毛虫分子多样性评价造成影响的浮游类群主要来自浅层水,洗脱DNA与cDNA测序均可显著降低浮游类群eDNA的影响。鉴于洗脱DNA法较之cDNA法操作更简便,且避免了反转录过程导致的偏差,因此推荐用于对近海沉积物中纤毛虫等真核微生物的分子多样性研究。 相似文献
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荧光法测定微型生物细胞内的ATP的技术 总被引：1，自引：0，他引：1
ATP是生物体内的重要化合物,可用于估算微型生物的生物量,因此它在生态系统食物链和能量流动研究中具有重要意义。根据ATP与荧光素反应产生荧光的原理,可对微型生物细胞内的ATP进行测定。荧光法测定微型生物细胞内ATP灵敏度高、操作简便快捷。本文从样品处理、ATP提取、ATP测定、干扰因素及应用等几个方面介绍了荧光法测定微生物细胞内ATP的技术,评述了这些技术的优缺点和适用范围,总结了ATP提取和测定时可能存在的干扰因素及其采取的相应对策。 相似文献
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从虾壳中分离到一株乳杆菌BR-3,研究发现其最佳发酵起始pH为6.50,最佳培养温度为35℃,在此培养温度下达到对数生长期的时间为42h。采用乳杆菌发酵方法,进行了虾壳制备甲壳素的研究,比较了接种量、葡萄糖加入量、发酵时间等因素对产品质量的影响。结果表明,当接种量为10%、葡萄糖浓度为4.5%、固液比为1︰3、发酵温度为(35±2)℃、发酵时间为3—4d时,平均灰分去除率达95.67%,甲壳素产品灰分含量均小于6%,最低可达1%,产品质量等于或优于传统的酸碱生产方法。发酵液可部分或全部回收,洗涤废水可作下一轮发酵用水,生产废水接近零排放。虾壳乳酸发酵法生产甲壳素是一种清洁生产方法。BR-3培养时间短,培养条件粗放,温度和pH适应范围宽,产酸效率高,残糖少,适合于工业化生产。 相似文献
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Although environmental factors such as grain size and organic carbon content may influence the distribution of microbes in marine sediments, there has been little experimental study of the topic to date. To investigate how those sediment variables affect microbial colonisation under in situ conditions, deep‐sea sediments and artificial sediments (glass beads, sands) were incubated in the Arctic deep sea at 2500 m water depth with or without chitin, one of the most important carbon polymers in marine environments. Microbial abundance, biomass, chitobiase activity and changes in community structure were monitored after 7 days and 1 year. In control sediments without chitin addition, no significant changes in microbial abundance, biomass and activity were observed after 1 year. In the presence of chitin, however, considerable increases in these parameters were recorded in all three sediment types tested. Regardless of chitin addition, natural deep‐sea sediments were always associated with higher values of microbial abundance, biomass and activity compared with artificial sediments. Sediment type was always found to be the most significant factor explaining variation in enzymatic activity and bacterial community structure as compared to the effects of chitin amount, incubation time, and changes in cell number or biomass. Overall, this is the first in situ study that has addressed the effects of multiple factors and their interactions on abundance, biomass, activity and community structure of microbial communities in the deep Arctic Ocean. 相似文献
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Reed Van Valin 《Marine Chemistry》1982,11(6):535-564
The characterization of solid phase-associated transition metals is important in understanding solid—seawater interactions. This has proven to be a difficult problem because of the complex nature of most sediments and suspended particulate matter. Many chemical techniques have been proposed to describe sedimentary metal phases. Most rely on characterizing equivalent chemical reactivities from the various metal phases rather than the characterization of the actual physical phases with which the metals are associated. In this study, several of the most widely used trace metal extraction techniques are compared for many of the most commonly measured transition metals using a variety of naturally occurring major marine sediment types. All solid concentrations are normalized to total metal values as obtained by neutron activation and X-ray fluorescence analyses.One weak, four intermediate strength, and two strong metal extraction methods were studied individually. The weak method had the lowest degree of extraction efficiency, but dissolved all solid carbonate phases. Its probable inability to retain released metals quantitatively in solution is a major problem. Three of the four intermediate methods are similar. The other and simplest of the four methods (0.5 N HCl), released much lower amounts of most metals studied when compared to these other three. It cannot be classified as a weak method, however, as it does attack some moderately resistant solid phases. Only one of the other three intermediate methods (a reducing acetic acid solution), was relatively free from analytical difficulties and it is preferred for this reason. The two strong extraction methods are quite similar, with neither yielding total metal concentrations.A five-step sequential extraction scheme was also evaluated. The results were generally quite good, both with regard to metal phase fractionation and overall total extraction of available metals. Based on the results of this study, a sequential extraction scheme is a useful method for characterizing solid phase-associated transition metals. 相似文献
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Reliable methods have been developed for the quantitative estimation of chitin, chitosan and chitin deacetylase in sediment samples, as well as two methods for the estimation of chitinase in these samples. The differing substrates used in the latter two methods have produced distinct ‘depth profiles’ for chitinase activity which suggest the presence of more than one chitinolytic system in the sediments of the Ythan estuary. Studies on the mineralization of chitin in these sediments have revealed a complex system with a number of unexpected features. The rate of chitin degradation was reduced in late summer, possibly due to the heavy seaweed growth which covers the mud flats at this time, although the potential degradative activities of the enzymes chitinase and chitin deacetylase were higher in summer than in winter. The proportional rates of degradation of chitin, chitosan and cellulose were similar in both the absence and presence of seaweed overgrowth, although the apparent rates of degradation of these substrates were higher in the absence of seaweeds. Core samples have indicated that the major input of chitin to the sediment ecosystem occurs via deposition at the surface, while the input of chitosan (the deacetylated polymer) occurs via its production within the sediment, primarily within the upper 5 cm of sediment. The concentrations of both these polymers decreased sharply below an ‘interface’ between aerobic and anoxic sediments. 相似文献
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海洋来源白浅灰链霉菌中环二肽类化合物的分离与结构鉴定 总被引：6，自引：0，他引：6
为了寻找新的抗肿瘤活性化合物，采用硅胶、Sephadex LH-20柱色谱和高效液相色谱，从白浅灰链霉菌Streptomyces albogriseolus(A2002)中分离得到3个环二肽；利用理化及波谱学方法鉴定其结构分别为环(丙氨酸-缬氨酸)[cyclo-(Ala-Val)，1]，环(丙氨酸-脯氨酸)[cyclo-(Pro-Ala)，2]和环(脯氨酸-酪氨酸)[cyclo-(Pro-Tyr)，3]。 相似文献
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基于变分水平集方法的浒苔绿潮面积信息提取 总被引：1，自引：1，他引：0
绿潮面积信息提取是绿潮遥感监测中极其重要的环节,其结果将直接影响后续的统计分析和预测预警工作。目前科研人员一般基于传统阈值方法对绿潮面积信息进行提取,其提取结果具有不稳定、效率低、人为因素影响大等缺点。针对上述问题,本文基于变分水平集的对偶方法和分裂Bregman投影方法对绿潮面积信息进行了提取,并提出一种对上述两种方法提取出的绿潮面积信息结果进行量化的新方法。分别基于传统阈值方法、变分水平集的对偶方法和分裂Bregman投影方法进行了3幅影像的绿潮信息提取实验,对提取结果进行了比对分析。实验结果表明,对分辨率较高的卫星遥感数据,无论从运行效率还是从绿潮面积信息提取结果的精确性及稳定性上,基于变分水平集的对偶方法和分裂Bregman投影方法均优于基于传统阈值方法。 相似文献
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绿藻水溶性多糖的研究概况和进展 总被引：1，自引：0，他引：1
对近年来绿藻多糖的提纯方法、组成结构及应用的研究进展进行了综述。绿藻多糖的提纯需要经过样品的前处理、提取和精制三个步骤,提取方法包括酸提、酶提、加入钙螯合剂提取、微波及超声波辅助提取。绿藻多糖是水溶性的硫酸化杂多糖。从石莼(Ulva)、浒苔(Enteromorpha)、礁膜(Monostroma)、小球藻(Chlorella)、蕨菜(Bracken)及刚毛藻(Bristles)中提取的多糖的化学组成及结构特征各不相同,而且多糖的化学组成和结构特征受提取方式的影响。绿藻多糖的生物相容性、生物可降解性及抗氧化、抗肿瘤、抗凝血、抗炎、免疫调节等多种生物活性使其在食品、医药、化妆品及农业中具有广泛的应用。有关绿藻多糖的精确结构、提纯方法及化学修饰的进一步研究将使绿藻多糖的应用更加广泛。 相似文献
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文章以湄公盆地周边海域为研究区,利用遥感技术手段,综合多时相、多源卫星数据,探讨不同数据源海上油气井平台提取方法。本次研究,首先基于1992—2018年27景多时相夜间灯光数据和2019年两期SAR数据,分别采用高斯滤波法和双参数CFAR法,实现了全区域油气井平台的自动化提取;然后,针对有确定性资料辅助判定的区域,采用人工目视解译的方法,对长时间序列Landsat-8 OLI及YG24号光学卫星影像进行提取,并将解译结果作为标准数据,用于验证前两种自动提取方法的精度。结果表明：夜间灯光影像数据易获取、成本低,提取方法简单,而SAR影像提取结果的精度高、流程烦琐,建议根据多源卫星数据的特点相互结合,实现快速、高效、精确的信息提取,应用于海上油气井平台监测。 相似文献