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1.
从北极海洋环境中筛选分离出一株产胞外碱性蛋白酶的革兰氏阴性杆菌 Ar/ W/ b/ 75°2 5′ N/ 1。该菌能在 7～ 30℃范围内生长 ,并且在 30℃条件下生长良好 ,但不能在 40℃条件下生长。该菌在 0 .5%～ 1 0 % Na Cl的盐浓度范围内能良好生长 ,表现出一定的嗜盐性。葡萄糖、蔗糖及可溶性淀粉等碳源物质可被该菌株利用以供生长之需 ,其中以葡萄糖最佳。氮源物质中 ,蛋白胨是最有利于菌株生长、产酶的有机氮源 ,而 NH4 NO3则是效果最好的无机氮源。对该菌蛋白酶的酶学特性研究表明 :所产胞外蛋白酶占其蛋白酶总量的 75.7%左右 ;蛋白酶反应的最适温度为40℃ ,酶活力在温度不高于 40℃条件下保持稳定 ;该菌蛋白酶具有较宽的 p H活性范围 ,在 p H7～ 1 1均表现出较高酶活力 ,其最适 p H在 8左右 相似文献
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自北冰洋楚科奇海、加拿大海盆、格陵兰海和中国南极中山站近岸的海水、海冰和沉积物样品中分离的322株低温细菌中筛选出73株低温β-半乳糖苷酶产生菌,并对其中1株BCw006进行了研究。通过16S rDNA序列同源性分析表明,该菌株属于交替单胞菌属,定名为Alteromonas sp.BCw006。对该菌株研究表明:该菌最适生长和产酶温度为24℃;在pH6.0—8.0、含0%—6.O% NaCl的培养基条件下菌株能够较好地生长与产酶,其最适生长和产酶NaCl浓度分别为3%和1%,乳糖对β-半乳糖苷酶合成具有明显诱导作用,酵母粉和蛋白胨是菌株生长和产酶较适宜的氮源,酶的最适作用温度为35℃,0℃时能保持35℃下酶活的25%左右,表明其具有较好的适应低温特性。酶对热敏感,60℃时作用30min后酶活力下降了41%。 相似文献
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覆盖在北极海洋上的广阔海冰为其内部生存的微生物群落提供了一个独特的生境。研究表明 ,大量海冰细菌能够分泌产生胞外酶 ,其中产蛋白或脂质水解酶细菌的比例远高于产多糖水解酶的细菌。温度、盐度是直接影响海冰细菌生存与活力的 2个主要环境因子。 76%的产酪蛋白酶海冰细菌为低温菌 ,菌株只能在 <35°C条件下生长 ;而 98%的酪蛋白酶最适作用温度≥ 35°C ,其中 62 %的酶最适作用温度≥ 45°C。几乎所有的产酪蛋白酶海冰细菌都耐盐或嗜盐 相似文献
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《中国沙漠》2016,(3)
为了探讨NO对碱胁迫下裸燕麦(Avena nuda)生理响应的调节作用,采用营养液培养,研究Ca~(2+)对外源NO供体硝普钠(SNP)所诱导的NaHCO_3胁迫下裸燕麦品种"定莜6号"幼苗生长、活性氧代谢和渗透溶质积累的影响。结果表明:25μmol·L-1SNP或6.5mmol·L-1 CaCl_2能够缓解75mmol·L-1 NaHCO_3胁迫对幼苗生长的抑制作用,叶片超氧化物歧化酶、过氧化氢酶、过氧化物酶、抗坏血酸过氧化物酶和质膜H+-ATP酶活性较单独NaHCO3胁迫处理明显增强,O·-2、H_2O_2、丙二醛含量显著下降,抗坏血酸、可溶性糖、可溶性蛋白质、脯氨酸含量和K+/Na+显著提高;添加SNP的同时增添Ca~(2+)通道抑制剂~La(3+)或Ca~(2+)螯合剂EGTA抑制了SNP的这些作用。Ca~(2+)在NO诱导的碱胁迫下裸燕麦活性氧清除能力和渗透溶质含量提高、维持离子平衡中起重要作用,NO的作用可能依赖于胞浆Ca~(2+)的浓度。 相似文献
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为了研究北极微藻对不同环境温度的适应性,对分离自北极王湾地区的三种微藻-玛氏骨条藻(Skeletonema marinoi)、小球藻(Chlorella sp.)和衣藻(Chlamydomonas sp.)在不同温度条件下(0℃、4℃和8℃)的生长曲线和抗氧化酶系统进行了测定.结果表明微藻对温度的适应性因种而异:玛氏骨条藻在4℃具有最快生长速率,最高的超氧化物歧化酶(SOD)和过氧化氢酶(CAT)酶活性,及最低的丙二醛(MDA)含量;小球藻的最快生长速率及酶活均在8℃时,MDA含量最低值出现在0℃;衣藻生长情况相差不大,MDA含量的最低值出现在8℃.抗氧化酶系统变化规律也因藻种及温度而异--在0℃与4℃变化时,玛氏骨条藻抗氧化酶系统的三个指标的差异极显著(P<0.01);在0℃与8℃变化时,玛氏骨条藻与小球藻的SOD活性的差异显著(P<0.05),其余两个指标差异不显著;衣藻在三个温度下的三个指标差异均不显著.总体而言,三种藻对三个温度的适应性均较好:其MDA的含量均较低,三种藻各自具有独特的生理代谢机制来适应不同的温度环境. 相似文献
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寡营养细菌(Oligographic bacteria)及其固沙作用的研究 总被引：3，自引：1，他引：3
从新疆古尔班通古特沙漠生物结皮的下层(沙物质层)分离到一株寡营养细菌,G +;细胞大小在0.328~0.746×0.171~0.240 μm;菌落圆形;直径5 mm,白色光滑,隆起明显;兼性好氧;该菌可在含碳量1~15 mg\5L-1培养基、10~70 ℃、pH值 5~11的环境中生长,较适宜生长温度范围为15~37 ℃;最适pH值范围为8~9;该菌在生长过程中分泌大量的黏多糖,室内培养72 h黏度可达9 000 mPa·S。将黏度为1 500 mPa·S的菌体培养液喷洒在流沙表面后,能够形成可以粘连沙粒约6 mm厚的寡营养细菌结皮层,该结皮层不仅能够固沙而且具有一定的减缓土壤中水分蒸发的效果。 相似文献
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对分离自北冰洋７３°Ｎ以北海域沉积物中的一株放线菌Ｒ５２７Ｆ进行分子鉴定及生物活性研究。通过对菌株的形态特征、培养性状、生理生化特征以及１６ＳｒＤＮＡ序列进行综合分析,确定该株菌为链霉菌属,暂定名为Ｓｔｒｅｐｔｏｍｙｃｅｓ ｓｐ．Ｒ５２７Ｆ。其含有聚酮类Ⅰ型（ＰＫＳⅠ）和非核糖体含硫多肽类（ｎｏｎｒｉｂｏｓｏｍａｌｐｅｐｔｉｄｅｓｙｎｔｈｅｔａｓｅ,ＮＲＰＳ）化合物的合成基因。对其抗菌活性及活性物质发酵条件进行了研究,实验结果表明,该菌株所产生的抗菌物质对枯草芽孢杆菌具有显著抑制效果,抑菌圈直径达到１８．２ｍｍ。适合其抗菌物质的发酵条件：种子液接种量为４％,培养基初始ｐＨ为８．０,培养温度为２８℃,培养时间为６ｄ,摇床转速为１８０ｒ?ｍｉｎ－１,装液量为４０％,为该菌株抗菌物质的进一步研究奠定发酵条件参数基础。 相似文献
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梯度太阳能池技术在盐湖化工中是一种经济分离无机盐产品的方法,本文创新性的采用等温蒸发法,模拟四元体系(LiCl + NaCl + Li2SO4 + Na2SO4 + H2O)在75℃等温蒸发相平衡,指导太阳池深池积温分离提取锂盐产品。实验测定了溶解度和溶液密度、pH值等物化性质,并绘制了干盐相图、水图和物化性质组成图。在该四元体系干盐相图中包含3个四元共饱点,7条单变量蒸发曲线和5个结晶区,分别为NaCl,Na2SO4,复盐Li2SO4·Na2SO4,Li2SO4·H2O和LiCl·H2O。采用 Pitzer模型和改进的HMW公式,拟合出该四元体系在75℃时的Pitzer单盐参数、混合离子作用参数和平衡固相的热力学平衡常数,并计算给该四元体系的相图,计算相图和实验相图有较大区别。等温蒸发相图能真实的反应盐湖中盐类沉积规律,并对指导太阳池分离盐类具有重要指导意义。 相似文献
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Screening and molecular classification of low-temperature protease from Antarctic microorganism and its characterization 
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下载免费PDF全文 <正> 107 strains producing protease were screened from 260 strains of Ant-arctic psychrophilic bacteria,among which proteolytic activity of five strains wasmore than 45 U ml~(-1).The 16S rRNA gene sequences homology and phylogenet-ic analysis of five Antarctic psychrophilic bacteria showed that NJ276、NJ5-9、NJ16-70、NJ345 belonged to the described genus Pseudoalteromonas and NJ341belonged to the genus Colwellia.The growth and the protease characteristic offour Antarctic psychrophilic bacteria had been studied,and the result showedthat the optimal temperature for growth and protease-producing of four strainswas about 10℃.Their growth and protease-producing were still high during in-cubating 2-5 days.The maximum proteolytic activity occurred at pH 9 for fourAntarctic psychrophilic bacteria.The optimal temperature of protease action ofboth strains NJ276 and NJ5-9 was about 50℃,however,the optimal temperatureof protease action of both strains NJ341 and NJ345 was about 40℃,and theirproteolytic activity under 0℃ exhibited nearly 30% of the maximum activity,but their thermal stabilities were weaker.These results indicated that proteasesfrom NJ341 and NJ345 were low-temperature proteases. 相似文献
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Effect of isolation temperature on the characteristics of extracellular proteases produced by Antarctic bacteria 总被引：1，自引：0，他引：1
Protease-producing psychrotolerant bacteria were isolated from Antarctic biotopes on casein agar plates using different incubation temperatures. Most of the isolates were non-spore-forming Gram-negative motile rods with catalase activity, 30% were pigmented and none of them were glucose fermenters. All the strains were grown in liquid cultures at 20°C and protease secretion was tested using the azocasein method. Despite their capacity for production of a clear zone of hydrolysis in agar plates, some strains did not produce detectable levels of proteolytic activity in liquid cultures. The lowest apparent optimum temperature for protease activity found in culture supernatants was 40°C. Almost all the strains showed activation energy values about 10-20 kJ-mol−1 lower than that observed for a mesophilic Subtilisin. Most of the proteases showed optimal activity at neutral or alkaline pH values and developed a multiple-band profile on gelatine-SDS-PAGE. It was observed that the lower the strain isolation temperature was, the more stongly cold-adapted–in terms of optimal temperature and activation energy–were the proteases produced by them. This dependence of the characteristics of the proteases on the isolation temperature is an important factor to take into account in the design of screening programmes directed towards the isolation of psychrotolerant bacteria able to produce proteases strongly or weakly adapted to work in the cold. The Antarctic area explored proved to be a promising source of proteolytic bacteria with potential use in industrial processes to be carried out at low or moderate temperatures. 相似文献
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Isolation and characterization of a marine bacterium producing protease from Chukchi Sea, Arctic 下载免费PDF全文
下载免费PDF全文 A Gram negative bacterium Ar/W/b/75°25′N/1 producing extracellular alkaline protease was isolated from surface water of latitude 75°25′N, and longitude 162°25′W in Chukchi sea, Arctic. The strain can grow at the temperature range from 7℃ to 30℃, and grow better at 30℃. It can not grow at 40℃. Keeping certain salinity concentration in medium is necessary for cell growth. It grows well in medium containing salinity concentration from 0.5% to 10% sodium chloride. Glucose, sucrose and soluble starch can be utilized by the strain, among which glucose is the optimal carbon source. Peptone is the optimal organic nitrogen source for cell growth and protease producing, and ammonium nitrate is the optimal inorganic nitrogen source. About 75 7% of total protease of the strain are extracellular enzyme. Optimal temperature for proteolytic activity is at 40℃. Protease of the strain keeps stable below 40℃, and shows high proteolytic activity within the pH range from 7 to 11. 相似文献
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Extracellular enzymatic activities of cold-adapted bacteria from polar oceans and effect of temperature and salinity on cell growth 下载免费PDF全文
下载免费PDF全文 The potential of 324 bacteria isolated from different habitats in polar oceans to produce a variety of extracellular enzymatic activities at low temperature was investigated. By plate assay, lipase, protease, amylase, gelatinase, agarase, chitinase or cellulase were detected. Lipases were generally present by bacteria living in polar oceans. Protease-producing bacteria held the second highest proportion in culturable isolates. Strains producing amylase kept a relative stable proportion of around 30% in different polar marine habitats. All 50 Arctic sea-ice bacteria producing proteases were cold-adapted strains, however, only 20% were psychrophilic. 98% of them could grow at 3% NaCl, and 56% could grow without NaCl. On the other hand, 98% of these sea-ice bacteria produced extracellular proteases with optimum temperature at or higher than 35℃, well above the upper temperature limit of cell growth. Extracellular enzymes including amylase, agarase, cellulase and lipase released by bacteria from seawater or sediment in polar oceans, most expressed maximum activities between 25 and 35℃. Among extracellular enzymes released by bacterial strain BSw20308, protease expressed maximum activity at 40℃, higher than 35℃ of polysaccharide hydrolases and 25℃ of lipase. 相似文献
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Studies on culture condition and extracellular hydrolase of psychrophilic bacteria from Arctic sea ice 下载免费PDF全文
下载免费PDF全文 Arctic sea ice in the polar region provides a cold habitat for microbial community.Arctic sea ice microorganisms are revealed to be of considerable impor- tance in basic research and potential in biotechnological application.This paper in- vestigated the culture condition and extracellular hydrolase of 14 strains of different Arctic sea ice bacteria.The results showed that optimal growth temperature of strains is 15℃or 20℃.The optimal pH is about 8.0.They hardly grow at acid condition. 3% NaCl is necessary for better growth.These strains have different abilities in pro- ducing amylase,protcase,cellulase and lipase.Pseudoalteronomas sp.Bsi429 and Pseudoalteronomas sp.Bsi539 produced both cellulose,protease and lipase.These results provide a basis for further developing and exploiting the cold adapted marine enzyme resources. 相似文献
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Isolation and characteristics of one marine psychrotrophic cellulase-generating bacterium Ar/w/b/75°/10/5 from Chuckchi Sea,Arctic 下载免费PDF全文
下载免费PDF全文 Microorganisms living in polar zones play an important part as the potential source of organic activity materials with low temperature characteristics in the bio-technological applications. A psychrotrophic bacterium (strain Ar/w/b/75°/10/5) , producing cellulose at low temperatures during late-exponential and early-stationary phases of cell growth, was isolated from sea ice-covered surface water in Chuckchi Sea, Arctic. This bacterium, with rod cells, was Gram-negative, slightly halophilic. Colony growing on agar plate was in black. Optimum growth temperature was 15℃. No cell growth was observed at 351 or above. Optimum salt concentration for cell growth was between 2 and 3 % of sodium chloride in media. Maximal cellulase activity was detected at a temperature of 35℃ and pH8. Cellulase was irreversibly inactivated when incubated at 55℃ within 30 min. Enzyme can be kept stable at the temperature no higher than 25℃. Of special interest was that this bacterium produced various extracellular enzymes i 相似文献
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采用纯培养方法从吉尔吉斯斯坦共和国伊塞克湖一处温泉旁的土壤中分离到32株细菌,通过ARDRA 分析后得到不同的类群,从各个类群中随机选取1个代表菌株进行16S rDNA 序列测定和系统发育的分析。结果表明：分离的菌株分布在假单胞菌属（Pseudomonas）、类芽孢杆菌属（Paenibacillus）、芽孢杆菌属（Bacillus）、寡养单胞菌属（Stenotrophomonas）、Lysinibacillus、溶杆菌属（Lysobacter）、短芽孢杆菌属（Brevibacillus）、根瘤菌属（Rhizobium）、变形杆菌属（Proteus）等9个属,且部分菌株的16S rDNA序列同源性低于97%,可能是潜在的新种。结果揭示了该样点可培养细菌种群的多样性及独特性。 相似文献
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Polarella glacialis最早发现于南极固定冰和北冰洋水层,最近在温带海域也发现其相关基因。专抗甲藻的Rubisco、PCNA抗体在该藻细胞内各检测到~53 kDa和~55 kDa的特异性条带。对该藻的梯度温度培养实验显示,4℃生长的P. glacialis细胞密度为1.1×105 cells/ml时仍能继续增殖,一天中藻细胞内Rubisco的表达量基本保持恒定,PCNA的表达量峰值与%S峰值相对应,当温度迅速上升至15、20℃时,藻株处于胁迫状态,细胞密度迅速减少,正常的细胞周期被干扰,大多数细胞分裂活动不活跃或停止分裂,Rubisco、PCNA的表达量大幅减少甚至消失,昼夜表达特征改变,其中20℃对藻株的胁迫作用更加显著。15℃培养下的P. glacialis细胞密度并不立即减少,细胞周期与两种指示蛋白表达特征显示仍有部分细胞完成分裂。本研究为该藻的相关基因在温带水域的出现提供了可能的解释,并推测在相对长期渐进的极地增温过程中,P. glacialis可能继续存在。 相似文献