一种具有纤溶活性的枯草杆菌蛋白激酶的研究──Ⅰ高产酶菌株的筛选与鉴定

本文主要阐述了一种具有纤溶活性的枯草杆菌（Ｂａｃｉｌｌｕｓｓｕｂｔｉｌｉｓ）蛋白激酶产生菌株的筛选与鉴定的研究结果。作者从初筛的１２株Ｂａｃｉｌｌｕｓｓｕｂｌｉｌｉｓ菌中,通过对固体发酵和液体发酵所产生的枯草杆菌蛋白激酶,用琼脂糖－纤维蛋白平板法测其活性,经比较不同菌株的活性,筛选出两株高产酶菌株：Ｂ．ｓｕｂｔｉｌｉｓＨＷ—１２和Ｂ．ｓｕｂｔｉｌｉｓＨＷ—３。同时对菌体和菌落形态特点、生理生化反应进行了鉴定,认为Ｂ．ＳｕｂｔｉｌｉｓＨＷ－１２菌株可用来做为发酵生产该酶的菌种。     

天目山物种多样性尺度依赖及其与空间格局关系的多重分形

以浙江省天目山国家级自然保护区为例,采用多尺度分析思想,利用多重分形分析方法,研究了不同尺度下物种多样性的变化、空间分布格局以及多样性与空间格局之间的关系。研究主要得到3方面的结论：（1）物种多样性具有尺度依赖性,随着空间尺度的增大,Shannon-Wiener多样性指数Ⅳ增大,Margalef多样性指数足和均匀度指数E减小;（2）多重分形参数αmin。多重分形谱的变化范围SR等能够定量反映物种的空间分布特征,空间大尺度越大,物种越聚集,空间分布越不均匀;（3）物种多样性与空间格局存在线性或幂函数关系。研究表明多重分形分析定量描述物种空间格局是有效性的,多重分形参数与生物多样性之间的定量关系为研究物种空间格局、生态属性与尺度之间的关系奠定了基础。因此,分形结合传统方法,在生物多样性方面的研究将有很大的潜在价值。     

单种群菌落分形结构的形成及其机制研究

在变形杆菌、绿脓杆菌单种群菌落分形结构的形成过程中,细菌的运动、潜－生序变化及环境的营养水平是菌落形成扩散限制聚合模型（ＤＬＡ）分数维图样的关键。对菌落环境的分析结果显示单种群菌落中非平衡环境的形成是菌落分形结构产生的根本机制     

多菌种混合发酵无醇饮料的研究

以大麦芽、大麦和大米为主料,优质红茶为辅料,依据微生物生理代谢与生态的基本原理,选择了三个菌种混合发酵,开发了一种新型发酵无醇饮料。采用的三个菌种是：酵母菌（Ｓａｃｃｈａｒｏｍｙｃｅｓｃｅｒｉｖｉｓｉａｅ）,嗜酸乳酸菌（Ｌａｃｔｏｂａｃｉｌｌｕｓａｃｉｄｏｐｈｉｌｕｓ）,弱氧化醋酸单胞菌（Ａｃｅｔｏｍｏｎａｓｓｕｂｏｘｙｄａｎｓ）。将上述菌种按一定比例（１：１：２）接种,接种总量为发酵基质的１０％,控制发酵温度２０－２５℃,发酵时间５天,即可制成风格独特、口味纯正的新型发酵无醇饮料（含醇量＜１％）。     

一种便于丝状真菌显微观察的培养方法

在真菌培养过程中,对其个体形态与群体（菌落）形态进行实时观察与鉴定是很必要的。本文利用半培养基培养法结合显微操作技术,对丝状真菌个体与群体进行形态学观察。结果表明,该方法无需染色与制片,不破坏菌丝正常生长状态,可实时进行形态学检测,对多个菌种在自然生长状态下的菌丝与菌落特征进行观察,操作简单、方便、快捷,从而降低了成本及工作量。     

多菌种混合发酵无醇饮料的研究*

以大麦芽、大麦和大米为主料,优质红茶为辅料,依据微生物生理代谢与生态的基本原理,选择了三个菌种混合发酵,开发了一种新型发酵无醇饮料。采用的三个菌种是：酵母菌（Ｓａｃｃｈａｒｏｍｙｃｅｓｃｅｒｉｖｉｓｉａｅ）,嗜酸乳酸菌（Ｌａｃｔｏｂａｃｉｌｌｕｓａｃｉｄｏｐｈｉｌｕｓ）,弱氧化醋酸单胞菌（Ａｃｅｔｏｍｏｎａｓｓｕｂｏｘｙｄａｎｓ）。将上述菌种按一定比例（１：１：２）接种,接种总量为发酵基质的１０％,控制发酵温度２０－２５℃,发酵时间５天,即可制成风格独特、口味纯正     

羊肚菌菌种继代培养代数与菌种退化关系

为探究羊肚菌继代培养代数同菌种退化的关系,对梯棱羊肚菌菌丝体进行继代培养,并对各代菌丝显微形态、菌落形态、菌丝生长速度和胞外酶活性进行观察和测定,以揭示母种的频繁继代与菌种退化的关系.研究结果表明:随着继代培养代数的增加,菌丝生长速度、菌丝显微形态、菌落形态以及酶活性总体呈现下降趋势,要保持菌种的优良性状及活性,继代代...     

鹤山南亚热带草坡生态系统的生物量和生产力研究

以能量利用效率研究为中心,系统研究并分析了鹤山南亚热带草坡多年的光合作用与总第一性生产力、生物量与生物量增量、气候生产力模型和能量利用效率等能量学特征。草坡的总生物量为１１．３０ｔ·（ｈｍ）－２·ａ－１,其生物量增量为１．３９８ｔ·（ｈｍ）－２·ａ－１;草坡的总第一性生产力为４５．５４ｔ·（ｈｍ）－２·ａ－１,净第一性生产力为９．１０８ｔ·（ｈｍ）－２·ａ－１,用于净光合作用耗热１０５．５ＭＪ·ｍ－２·ａ－１,净光合耗热中又仅有２１．１ＭＪ·ｍ－２·ａ－１,用于净第一性生产力,净第一性生产力中又仅有３．２４ＭＪ·ｍ－２·ａ－１用于生物量增量;草坡生态系统的光能利用效率为０．０７％。草坡的能量利用效率是很低的     

拟南芥基因转移新方法—真空渗入法的研究

以拟南芥生态型Ｌａｎｄｓｂｅｎｇｅｒｅｃｔａ为试材,在含有所构建的ＣａＭＶＢａｒｉ－１株系基因ＶＩ的质粒（ＰＪ０５３０∷Ｂａｒｉ－１ＧＶＩ）的根癌农杆菌（Ａｇｒｏｂａｃｔｅｒｉｕｍｔｕｍｅｆａｃｉｅｎｓ）菌种ＧＶ３１０１的介导下,研究了基因转移的新方法－真空渗入法。     

地生枝顶孢固体培养的形态学研究

本文利用固体培养方法,对地生枝顶孢（Acremonium terricola)AT-01菌株的部分形态特征进行了研究,结果表明：低温有利于ＡＴ－０１菌株表现原始的淡粉红色菌落特征。在利用不同的氮源时,其微观形态常有所不同,宏观上的菌落特征也有差异。蔗糖浓度为６％时显著抑制该菌株菌落直径生长,而不同的蔗糖浓度均对菌落高度有显著影响。     

Comparing monofractal and multifractal analysis of corrosion damage evolution in reinforcing bars

Based on fractal theory and damage mechanics, the aim of this paper is to describe the monofractal and multifractal characteristics of corrosion morphology and develop a new approach to characterize the nonuniform corrosion degree of reinforcing bars. The relationship between fractal parameters and tensile strength of reinforcing bars are discussed. The results showed that corrosion mass loss ratio of a bar cannot accurately reflect the damage degree of the bar. The corrosion morphology of reinforcing bars exhibits both monofractal and multifractal features. The fractal dimension and the tensile strength of corroded steel bars exhibit a power function relationship, while the width of multifractal spectrum and tensile strength of corroded steel bars exhibit a linear relationship. By comparison, using width of multifractal spectrum as multifractal damage variable not only reflects the distribution of corrosion damage in reinforcing bars, but also reveals the influence of nonuniform corrosion on the mechanical properties of reinforcing bars. The present research provides a new approach for the establishment of corrosion damage constitutive models of reinforcing bars.     

La géométrie fractale pour l’analyse de signaux médicaux : état de l’art

The diagnostic interpretation of medical images is a complex task aiming to detect potential abnormalities. One of the most used features in this process is texture which is a key component in the human understanding of images. Many studies were conducted to develop algorithms for texture quantification. The relevance of fractal geometry in medical image analysis is justified by the proven self-similarity of anatomical objects when imaged with a finite resolution. Over the last years, fractal geometry was applied extensively in many medical signal analysis applications. The use of these geometries relies heavily on estimation of the fractal features. Various methods were proposed to estimate the fractal dimension or multifractal spectrum of a signal. This article presents an overview of these algorithms, the way they work, their benefits and limits, and their application in the field of medical signal analysis.     

北部湾近海珊瑚礁区系沉积物抗菌活性放线菌类群

通过对大肠埃希菌和枯草芽胞杆菌抗菌活性初步筛选,从北部湾近海珊瑚礁区5个沉积物样品中成功分离得到51株具有不同抗菌活性的放线菌,其中9株具有较强抗菌能力。根据这9株放线菌的菌落和孢子形态,可确定它们都属于链霉菌属。 RAPD-PCR分析表明这9株放线菌为6种不同类型,16S rDNA序列和系统发生树分析表明,9株放线菌可划分到4个大的类群6种不同类型,且结果显示RAPD-PCR聚类分析与16S rDNA序列聚类分析的结果具有较大的一致性。生理生化鉴定结果表明,分离株与亲缘关系最近的放线菌模式菌株的生理生化特征均存在差异,这说明分离株为放线菌新种的可能性比较大。这6种放线菌具有较为广谱的抑菌活性,并且抑菌活性均存在一定的差异,说明其可能分泌出多种结构功能不同的活性次生代谢产物。研究结果表明,广西北部湾近海珊瑚礁区系沉积物蕴藏着丰富的可供药物开发的放线菌资源。     

Fat fractal and multifractals for protein and enzyme surfaces.

The roughness and irregularity of the surfaces in the protein and enzyme are fractal features that may be characterized by fractal dimensions and mass exponents. The surface fractal dimensions calculated by the variation method are different from those obtained by other methods, since the former is applicable to the self-affine system. Thus the results reported here are reliable for the surfaces. However, the fat fractal and multifractal features of proteins and enzymes are studied by simulation. The surface mass exponents are regarded as another kind of scaling exponent, and the spectrum f(alpha) provides further detailed information about the surfaces of enzyme and protein. The applications of the spectrum f(alpha) to the enzymatic reactions is also discussed.     

New and highly efficient methodology for screening high-yield strains of cytotoxic deacetylmycoepoxydiene (DAM)

Aims: To establish a highly efficient methodology for screening high yield strains of cytotoxic deacetylmycoepoxydiene (DAM), to meet the need of research on its mechanism of anti‐tumor properties and in vivo toxicity studies. Methods and Results: A simple, sensitive, and highly repetitive screening procedure ‘Antimicrobial‐TLC–HPLC’ (ATH) was established for the rapid obtaining of high‐yielding DAM mutants to replace the time and labor intensive anti‐tumor activity assay (MTT). With this ATH method, four highly yielding DAM mutants were selected out of 5000 total mutants, one of which, M4‐143, showed yields of more than 300 times (250·3 mg l^?1) that of the parent strain A123. Conclusions: The ATH method developed in this work has proven to be both economical and highly efficient with the screening of 1200 mutants in a one week time period, thusly shortening the expenditure of time and labor, without missing a single high‐yield mutant. Due to these characteristics, it is superior to other HTS screening methods described in earlier literature. The mutant M4‐143 has a good genetic stability and can be used for further research. Significance and Impact of the Study: This ATH screening method is not only perfect for screening high‐yield DAM mutants, but also, it is suitable to screen the strain libraries for those strains that have the ability to produce natural metabolites with antitumor activity.     

Detection of phlD gene in some fluorescent pseudomonads isolated from Iran and its relative with antifungal activities

Fluorescent pseudomonads that produce antibiotic 2,4-diacetylphloroglocinol (2,4-DAPG) are important group of PGRP that inhibit a broad spectrum of plant pathogenic fungi. Studying on genetic diversity of 2,4-diacetylphloroglucinol-producing fluorescent pseudomonads has been shown with special importance. The first step to investigate the genetic diversity of these bacteria is detecting of the genes required for the biosynthesis of this antibiotic. The objectives of the current study were detection of phlD gene within fluorescent pseudomonads by a PCR-based assay, and comparison of phenotypic and genotypic characteristics of fluorescent pseudomonads with proven biocontrol potential against some soil-borne phytopathogenic fungi. We used a collection of 47 fluorescent Pseudomonas spp. some with known biological control activity against Macrophomina phaseolina, Rhizoctonia solani, Phytophthora nicotianae var. parasitica, Pythium sp. and Fusarium sp. in vitro and the potential to produce known secondary metabolites such as, siderophore, HCN and protease. The results indicated that 66, 40.42, 63.82,48.94 and 27.65% of strains revealed antagonistic activity against R. solani, M. phaseolina, Pythium sp., P. nicotianae and Fusarium sp., respectively. Rhizoctonia solani recognized as the most vulnerable fungus. Among 47 strains, 76.59, 97.87 and 17% of strains produced protease, siderophore and HCN, respectively. We could detect phlD gene in strains P-5, P-32, P-47. Strain CHA0 was used as positive control for the detection this gene. Overall, there was no obvious link between the existence of phlD gene and inhibition of fungal growth or production of the antifungal metabolites in vitro. But in some strains such as CHA0 and P-5, we saw a link between the existence of phlD and antifungal activities. Studying on detection and diversity of phlD provides a fundamental knowledge for developing a rapid genetic screening system to identify a potential biocontrol strains.     

Evidence of multifractality from emerging European stock markets

We test for the presence of multifractality in the daily returns of the three most important stock market indices from Central and Eastern Europe, Czech PX, Hungarian BUX and Polish WIG using the Empirical Mode Decomposition based Multifractal Detrended Fluctuation Analysis. We found that the global Hurst coefficient varies with the q coefficient and that there is multifractality evidenced through the multifractal spectrum. The exercise is replicated for the sample around the high volatility period corresponding to the last global financial crisis. Although no direct link has been found between the crisis and the multifractal spectrum, the crisis was found to influence the overall shape as quantified through the norm of the multifractal spectrum.