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1.
空肠弯曲菌肠毒素理化特性的研究 总被引:3,自引:0,他引:3
经SDSPAGE 分析发现,空肠弯曲菌细胞紧张性肠毒素(Cytotonic enterotoxin ,CE) 的硫酸胺盐析粗提物除有一条68kD 的带外,还有一些未分开的小分子物质,而经神经节苷脂GM1 亲和层析后仅有68KD 的一条带,即表明68kD 的蛋白质为CE 的主要成分。CE 不耐热、pH 依赖和对胰酶有抗性。56 ℃和60 ℃加热30min 、100 ℃加热15min 即可完全失活。其活性在pH6-0 时最高,在pH3-0 和9-0 时均可使其完全丧失活性。在4 ℃保存超过3d 后,其活性迅速降低。抗LT 血清能完全抑制CE 的活性。 相似文献
2.
采用自制的壳聚糖为载体对单宁酶(TA)固定化,TA与壳聚糖配比1:2.5,30℃固定2h,活力回收达23.6%~33.1%;偶联效率为84.9%~88.0%。固定化单宁酶(ITA)的表观Km值(以没食子酸丙酯为底物)为22.2×10-6mol/L,TA的Km值(以没食子酸丙酯为底物)为10×10-6mol/L,TA和ITA的最适反应温度分别为40℃和50℃;60℃处理15min,残存活性分别为13.6%和60.3%。TA和ITA的最适pH值分别为5.8和6.4;TA在pH4.8~7.8活力稳定,而ITA活力稳定范围在pH4.8~6.8.ITA作用于EGCG的半衰期为78.7h,EGCG水解率达90.3%。对茶多酚提取物进行水解,其所含的酯型儿茶素EGCG和ECG水解率分别为96.4%和96.8%,非酯型儿茶素EGC和EC的含量显著增加。 相似文献
3.
产生抗肿瘤抗生素Sandramycin的南极放线菌C3905 总被引:3,自引:1,他引:2
从南极乔治王岛土壤分离到一株诺卡氏菌形放线菌C3905菌株。其气生菌丝白色,基内菌丝无色至乳脂或浅粉;菌丝直径0.5~0.8μm,断裂为杆状和球状体,表面光滑。胞壁化学I型;无枝菌酸;磷酸类酯PI型;优势甲基萘酯为MK9(H4)。DNA中G+C含量为68.3~68.9mol%。兼性嗜冷,生长适温为15℃~20℃。产生抗肿瘤抗生素sandramycin。基于以上特征及分子遗传分类的研究结果,我们建议C3905菌株作为白色类诺卡氏菌的一个变种,命名为白色类诺卡氏菌南极变种,Nocardioides albus var.antarcticus。 相似文献
4.
5.
链霉菌Z94-2碱性脂肪酶产生条件及酶学性质 总被引:2,自引:0,他引:2
在152 株脂肪酶产生菌中,链霉菌Z942 产脂肪酶活力为596u/ mL,其最适培养基(g/L) 为:糊精10 、黄豆饼粉30 、尿素10 、K2HPO4 0-5 、MgSO4 0-5 、NaCl 1 和AEO9 0 .5 ,产酶的最适条件为:初始pH9 .5 ~10-0 ,在26 ℃培养48h 。用PVA 橄榄油乳化系统测定该酶的最适pH9 .8 ,最适温度37 ℃,在pH8-6 ~10-2 于5 ℃存放24 h ,酶活力不变。0-14mol/L 的氯化钙有较大的激活作用。 相似文献
6.
适于非水相催化用细菌脂肪酶基本性质的研究 总被引:3,自引:0,他引:3
对假单胞菌产脂肪酶的基本酶学性质进行了研究.该酶水解油脂时的最适作用pH为9.0,最适作用温度为45℃;在pH7.0~10.0范围内稳定,在60℃以下热稳定性良好.K+、Ca2+、Mg2+等金属离子对酶有明显的激活作用,而Hg2+、Cu2+、Sn2+等重金属离子却对酶有较强的抑制作用;几种表面活性剂和胆汁盐均使酶发生不同程度的失活.该酶在水解油脂时表现出1,3-位置专一性,且对不同种类和来源的油脂水解作用速率不同 相似文献
7.
本文对230只大白鼠和148只褐家鼠主动脉弓的分支情况做了观察和分析,共见到六个类型,各型的出现率为:A型,大白鼠96.96±1.13%;褐家鼠99.32±0.6%;B型,大白鼠0.87±0.61%,C型,大白鼠0.43±0.43%;F型,大白鼠1.30±0.75%,H′型,大白鼠0.43±0.43%,AL型,褐家鼠0.68±0.68%。A型为大白鼠和褐家鼠主动脉弓分支的基本类型。在不同的鼠群中,亚型的出现率差异显著.AL型为本文首次报道. 相似文献
8.
链霉菌Z94-2碱性脂肪酶产生条件及酶学性质 总被引:2,自引:0,他引:2
在152株脂肪酶产生菌中,链霉菌Z94-2产脂肪酶活力为596u/mL,其最适培养基(g/L)为:糊精10、黄豆饼粉30、尿素10、K2HPO40.5、MgSO40.5、NaCl1和AEO90.5,产酶的最适条件为:初始pH9.5~10.0,在26℃培养48h。用PVA橄榄油乳化系统测定该酶的最适pH9.8,最适温度37℃,在pH8.6~10.2于5℃存放24h,酶活力不变。0.14mol/L的氯 相似文献
9.
钟形斑褶菇的生理特性和子实体的培养研究 总被引:1,自引:0,他引:1
首次报道了钟形褶菇的苗种分离、菌丝体生理特性和栽培技术。钟形斑褶菇菌丝具有明显的锁状联合。菌丝生长适宜的温度是10~40℃,最适为20~25℃;适宜的pH范围是4.5~13,最适为6~8.5;培养料适宜的含水量为45%~75%,最适为65%~70%;最佳的C源是:淀粉、蔗糖、纤维素;酵母粉、干酪素、硫酸铵、硝酸铵为最佳氮源。麦芽、麸皮、松针、干平菇、小麦、牛粪等天然材料的热水提取物对菌丝生长有利。子实体形成的温度范围为 20~35℃,最适宜的温度范围应为24~30℃,正常的出菇季节为4~9月;最适宜的空气相对湿度应为70%~85%;子实体具有向光性、负向地性。栽培出菇的培养料为牛粪粉、草粉、麸皮及食用菌栽培的废料。瓶、袋栽均可,干物质生物学效率2%~5%。新鲜木屑、棉籽壳不适宜菌丝生长和出菇。说明该菌是草腐生菌物。子实体可直接在培养料上形成,出菇不需要覆刺激。 相似文献
10.
产碱性纤维素酶的嗜碱芽孢杆菌SHY8-5725发酵液经絮凝预处理后,采用混合盐析方法沉淀酶,盐析收率可达95%以上,所制得酶粉CMCase可达500u/g以上。酶的最适pH为8.0和10.5,稳定pH范围为4~12;最适温度为45℃(pH9.0,10min)稳定温度范围为50℃(pH9.0,30min)以下;洗衣粉中各种表面活性剂和助剂对CMCase基本无影响,酶的底物特异性表明,该碱性纤维素酶主 相似文献
11.
Dastager SG Lee JC Ju YJ Park DJ Kim CJ 《Journal of microbiology and biotechnology》2008,18(7):1203-1206
A Gram-positive strain designated as MSL-14T isolated from a soil sample collected from Bigeum Island, Korea, was subjected to polyphasic taxonomy. The isolate was strictly aerobic. Cells were short rods and motile. Optimum growth temperature and pH was 28 degrees and 7.0, respectively. It was characterized chemotaxonomically as having a cell-wall peptidoglycan type based on LL-2,6-diaminopimelic acid and MK-8(H4) as the predominant menaquinone. The major fatty acids were iso-C16:0, C17:1 omega8c, and C18:1 omega9c. The G+C content was 67.6 mol%. Phylogenetic analysis based on the 16S rRNA gene sequence revealed that strain MSL-14T is affiliated to the genus Nocardioides and formed a distinct lineage within the genus. MSL-14T showed highest sequence similarity to Nocardioides aestuarii JCM 12125T, having a similarity of 96.5%. Based on the 16S rRNA gene sequence divergence and phenotypic characteristics, it is proposed that strain MSL-14T should be classified as representing a novel member of the genus Nocardioides, for which we propose the name Nocardioides tritolerans sp. nov. The type strain is strain MSL-14T (=KCTC 19289T= DSM 19320T). 相似文献
12.
类诺卡氏属放线菌的研究进展 总被引:1,自引:0,他引:1
Prauser H.最初于1976年从土壤中分离到17株诺卡氏形态放线菌,综合形态、生理生化特性和部分化学分类特征的研究结果,提议建立了一个新属——类诺卡氏属(Nocardioides),并以新种白色类诺卡氏菌(N.albus)为典型种。之后,随着分离、纯培养和分类方法的发展,越来越多的新成员从各种不同环境中分离得到。尽管这些菌来源广泛,形态和生理生化等特征各异,但他们拥有共同的属的特征。过去的50年中,随着放线菌研究的发展,该属中部分成员历经了分类地位的变迁和修订。到目前为止,该属共收纳了56个有效描述种。类诺卡氏属(Nocardioides)放线菌在农业、工业、化工业等方面也曾有应用研究报道。本文就类诺卡氏属放线菌的建立依据,属的特征,属内种的分布和变更以及它们在工农业上的应用研究前景及进展进行了综述。 相似文献
13.
A teichoic acid of Nocardioides albus VKM Ac-805T cell walls, a typical species of the genus Nocardioides, contains a poly(glycosylglycerol phosphate). The repeating unit of the polymer has the structure: [figure]. These units are in phosphodiester linkage at C-3 of glycerol and C-3 of beta-D-galactopyranose. beta-D-Galactopyranosyl residues are substituted at C-4 by beta-D-glucopyranose carrying a 4,6-pyruvate ketal group in S-configuration. The presence of pyruvic acid in the majority of repeating units increases the anionic properties of the polymer in comparison with most other common teichoic acids. This is the first report of the occurrence of a beta-D-galactofuranosyl residue in teichoic acids; it probably acts as a terminator of an extending chain of the polymer. The ratio of beta-D-galactopyranosyl to beta-D-galactofuranosyl units is 7:1. The polymer structure was determined by NMR spectroscopy. This type of teichoic acid structure has not been reported previously. 相似文献
14.
Kubota M Kawahara K Sekiya K Uchida T Hattori Y Futamata H Hiraishi A 《Systematic and applied microbiology》2005,28(2):165-174
Seven strains of dibenzofuran (DF)-degrading bacteria isolated from dioxin-polluted environments were characterized. These isolates were able to grow with dibenzofuran as the sole carbon and energy source. During the growth with dibenzofuran, they produced a soluble yellow metabolite that exhibited a unique pH-dependent shift of absorption maxima. Dibenzo-p-dioxin and biphenyl were also degraded with pigment production. The isolates were strictly aerobic and chemoorganotrophic and had gram-positive, nonmotile, rod-shaped cells. Chemotaxonomic analyses showed that cells contained L,L-diaminopimeric acid in the peptidoglycan, branched-chain fatty acids as major fatty acids, and menaquinone MK-8(H4) as the sole respiratory quinone. The G + C content of the DNA of the isolates ranged from 72.0 to 72.4 mol%. The 16S rRNA gene sequences of the isolates were very similar to each other (> or = 99.8%). The phylogenetic analysis showed that the isolates formed a cluster with species of the genus Nocardioides with Nocardioides simplex and Nocardioides nitrophenolicus as their nearest neighbors. DNA-DNA hybridization studies showed that the isolates showed a hybridization level of less than 55% to any tested species of the genus Nocardioides. Based on these data, Nocardioides aromaticivorans sp. nov. is proposed for the new DF-degrading isolates. The type strain is strain H-1 (IAM 14992, JCM 11674, DSM 15131). 相似文献
15.
Lawson PA Collins MD Schumann P Tindall BJ Hirsch P Labrenz M 《Systematic and applied microbiology》2000,23(2):219-229
16.
The strain designated Actinoplanes sp. 220 differed in its characteristics from other strains of the genus Actinoplanes listed in Bergey's Manual (1974). The strain belongs to psychrophilic culture growing within the range of 0-30 degrees C. The optimal temperature for growth on yeast--malt agar is 10-23 degrees C. Cultures transferred at 23 and 28 degrees C differed in morphological and physiological properties, enzyme activity and pigmentation in standard media. Submerged culture transferred at 28 degrees C inhibited growth of Bacillus subtilis ATCC 6633 and ATCC 9945. LL-2,6-Diaminopimelic acid was chromatographically detected in the submerged mycelium of this culture. This compound was not found in the mycelium of the original culture transferred at 23 degrees C. The cultures did not substantially differ in the composition of other amino acids contained in larger quantities in the mycelium. 相似文献
17.
石油降解菌株的分离鉴定及降油特性 总被引:1,自引:0,他引:1
从甘肃华庆油田污染严重的土壤中采样,通过富集培养、多次筛选分离得到1株优势菌F1。依据生理生化特征和16S rDNA序列将菌株F1鉴定为白色类诺卡氏菌(Nocardioides albus)。GS-MC结果表明,等量原油经F1菌株降解前、后,表现出先降解高碳数正构烷烃为低碳数正构烷烃;高碳数正构烷烃中奇数碳向偶数碳正构烷烃演化规律;平均降油率为64%,F1菌株能较好地促使五环三萜类化合物立体构型中不稳定构型向稳定性构型转化。F1菌株在含油浓度0.3%、0.5%、1.0%土样中降解石油烃的半衰期分别为17.2、18.2、23.7 d,42 d后均达到78%以上。 相似文献
18.
Piutti S Semon E Landry D Hartmann A Dousset S Lichtfouse E Topp E Soulas G Martin-Laurent F 《FEMS microbiology letters》2003,229(1):111-117
We report the characterisation of Nocardioides sp. SP12, an atrazine-degrading bacteria isolated from atrazine-treated bulk- and maize rhizosphere soil. Based on 16S rDNA alignment, strain SP12 showed close phylogenic relationships with Nocardioides sp. C157 and Nocardioides simplex. Internal transcribed spacer (ITS) sequences of strain SP12 were longer than those of other Nocardioides sp. and present Ala- and Ile-tRNA unlike Actinomycetales. Nocardioides sp. SP12 presents a novel atrazine catabolic pathway combining trzN with atzB and atzC. Atrazine biodegradation ends in a metabolite that co-eluted in HPLC with cyanuric acid. This metabolite shows an absorption spectrum identical to that of cyanuric acid with a maximal absorption at 214.6 nm. The mass of the atrazine metabolite is in concordance with that of cyanuric acid according to mass spectrometry analysis. Quantitative PCR revealed that the ITS sequence of Nocardioides sp. SP12 was at a lower number than the one of trzN in atrazine-treated soil samples. It suggests that trzN could also be present in other atrazine degrading bacteria. The numbers of trzN and ITS sequences of Nocardioides sp. SP12 were higher in the maize rhizosphere than in bulk soil. 相似文献
19.
Molecular taxonomic studies were performed on two LL-diaminopimelic acid-containing coryneform isolates from herbage. The results indicate that the herbage strains represent a new species of the genus Nocardioides for which the name Nocardioides fastidiosa sp. nov. is proposed. The type strain is NCIB 12713. 相似文献
20.
Resistance to oleandomycin in Streptomyces antibioticus, the producer organism, was studied. The organism was highly resistant in vivo to the antibiotic but sensitive to other macrolides and lincosamides. Protein synthesis in vivo by mycelium of S. antibioticus was more resistant to oleandomycin than that by mycelium of Streptomyces albus G, an oleandomycin-sensitive strain, and this resistance was dependent on the age of the culture, older mycelium of S. antibioticus being more resistant to oleandomycin than young mycelium. [3H]Oleandomycin was capable of binding to the same extent to the 50S subunits of the ribosomes of both organisms. Oleandomycin also inhibited in vitro protein synthesis by ribosomes obtained from an oleandomycin-production medium at the time when maximum levels of oleandomycin were being produced. A clear difference between the ability of the two organisms to incorporate exogenous oleandomycin was observed. Thus, while S. albus G took up oleandomycin, S. antibioticus showed a decreased permeability to the antibiotic, suggesting a role for cell permeability in self-resistance. 相似文献