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一株海洋好氧反硝化细菌的鉴定及其好氧反硝化特性 总被引:4,自引:1,他引:4
【目的】从处理海洋养殖循环水的生物滤器生物膜中分离到1株具有好氧反硝化活性的细菌(菌株2-8),并进一步研究了该菌的分类地位及反硝化特性。【方法】采用16S rRNA基因序列分析对菌株进行初步鉴定,采用好氧培养技术,探讨了碳源种类、起始pH、NaCl浓度、C/N、温度和摇床转速对菌株2-8好氧反硝化活性的影响。【结果】该菌株的16S rRNA基因序列与Pseudomonas segetis FR1439T(AY770691)的相似性最高,达到99.9%,因此初步鉴定菌株2-8属于假单胞菌属(Pseudomonas sp.2-8)。碳源类型和C/N对其好氧反硝化作用的影响最为显著,以柠檬酸钠为唯一碳源,C/N为15时脱氮效率最高,低C/N导致亚硝酸盐的积累;其好氧反硝化的最适温度和pH分别为30℃和7.5;菌株2-8在摇床转速为160r/min下脱氮效果最好;NaCl浓度对其反硝化活性的影响不明显。【结论】在初始硝酸氮浓度为140mg/L,以柠檬酸钠为唯一碳源、C/N为15、pH为7.5、NaCl浓度为30g/L,30℃以及160r/min摇床培养的条件下,菌株2-8在48h内脱氮率可达92%且无亚硝酸盐积累。 相似文献
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筛选聚乙烯醇(PVA)降解性能优良且适合驯化的菌种是PVA生物降解的关键环节。为了获取PVA高效降解菌种,采用选择性培养基从某化工厂回流池污泥中筛选菌株,并对菌株的生长及PVA降解过程、培养液pH值、温度、摇床转速、装液量进行测定。结果表明:筛选的1株聚乙烯醇高效降解菌MH 007,基于16S rRNA基因序列的系统发育多样性分析鉴定该菌为Sphingopyxis terrae的一个菌株。该菌PVA降解率可达97.2%,摇床动态培养过程中降解PVA的最佳条件为pH 7.2、温度30 ℃、摇床转速120 r/min和30%的装样量。 相似文献
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BA-25菌株碱性纤维素酶产酶条件优化研究 总被引:1,自引:0,他引:1
试验研究了分离自烟草调制过程中的产芽孢细菌Bacillussp.BA-25菌株碱性纤维素酶产生的优化条件.结果表明:麸皮是最佳碳源,豆饼粉是最佳的氮源,且当碳氮比为2∶1时产酶活性最高;NaCl和KH2PO4对纤维素酶的合成具有重要作用,其适宜用量分别为0.5%~1.0%和0.1%;培养液的初始pH会极大地影响产酶活性,其最适pH为10.最优化的发酵工艺参数为:种子菌龄为24h,在300mL摇瓶中,装入30mL培养基培养温度为37℃,摇床转速为160r/min,在发酵24h后补充1%的葡萄糖,培养48h,该菌产碱性纤维素酶活力可以达到68.4U/mL. 相似文献
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对基因工程菌1020培养基成分及培养条件进行了优化。结果表明,Mg2+、Mn2+、Zn2+三种金属离子可促进发酵产木聚糖酶。180 r.m in-1的摇床转速可满足70 mL/500 mL装液量的溶氧需求。最适培养温度为30℃,pH值为7.0。优化后的酶活为优化前的2.09倍。全细胞木聚糖酶的酶学性质表明该酶有两个最适pH值,分别为7.0与9.0。金属离子Ca2+,Fe3+,Fe2+对酶活有促进作用。pH7.0时Km为36.7095 mmol.L-1,Vm为0.3829 mmol.L-1.m in-1;pH9.0时Km29.9945mmol.L-1,Vm 0.2165 mmol.L-1.m in-1。 相似文献
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Xenorhabdus nematophila YL001培养基筛选和培养条件优化 总被引:2,自引:1,他引:1
筛选得到一株昆虫病原线虫共生菌X.nematophilaYL001,进行了基础培养基的筛选及培养条件优化研究。结果表明最佳发酵条件为:初始pH 7.0,250 mL三角瓶装液25 mL,摇床转速220 r/min,培养温度28.0℃,接种量9.0%,在此条件下菌体生长量和抗菌活性分别达到23.28 g/L和30.00 mm,抑菌圈直径增大23.3%,细胞干重增加52.97%。 相似文献
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The surface structures of Thiobacillus ferrooxidans were studied. When growing on a medium containing elemental sulphur, the cells possess peritrichously located filaments (piles) whose diameter varies from 4.5 to 7.0 nm and length, from 0.7 to 3.0 mcm. The cells of T. ferrooxidans do not have piles on a medium with ferrous iron. The physiological role of these structures for thiobacilli is discussed. 相似文献
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The obligately autotrophic acidophile Thiobacillus ferrooxidans was grown on elemental sulfur in anaerobic batch cultures, using ferric iron as an electron acceptor. During anaerobic growth, ferric iron present in the growth media was quantitatively reduced to ferrous iron. The doubling time in anaerobic cultures was approximately 24 h. Anaerobic growth did not occur in the absence of elemental sulfur or ferric iron. During growth, a linear relationship existed between the concentration of ferrous iron accumulated in the cultures and the cell density. The results suggest that ferric iron may be an important electron acceptor for the oxidation of sulfur compounds in acidic environments. 相似文献
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G A Zavarzin 《Mikrobiologiia》1972,41(2):369-370
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Submicroscopic organization of Thiobacillus ferrooxidans 总被引:1,自引:0,他引:1
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Two solid medium formulations, designated 100:10 and 10:10, were developed for the growth of Thiobacillus ferrooxidans. The new media contain a mixture of both ferrous iron and thiosulfate as available energy sources, permitting the detection of colony morphology variants that arise spontaneously in a wild-type population. Several morphological and physiological characteristics of a class of T. ferrooxidans variants, termed LSC for large spreading colony, are described. LSC variants lack the ability to oxidize iron but retain the capacity to utilize thiosulfate or tetrathionate as energy sources. An LSC colony spreads on the surface of solid 100:10 medium as a monolayer of cells in a fashion resembling that of certain swarming or gliding bacteria. The LSC variant reverts to a parental wild type at frequencies that vary in different independently arising isolates. The identity of the LSC variant as a derivative of the parental wild-type T. ferrooxidans was established by Southern blot hybridization. 相似文献
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Tsuyoshi Sugio Kouichi Hirayama Kenji Inagaki Hidehiko Tanaka Tatsuo Tano 《Applied microbiology》1992,58(5):1768-1771
Thiobacillus ferrooxidans AP19-3 oxidized molybdenum blue (Mo5+) enzymatically. Molybdenum oxidase in the plasma membrane of this bacterium was purified ca. 77-fold compared with molybdenum oxidase in cell extract. A purified molybdenum oxidase showed characteristic absorption maxima due to reduced-type cytochrome oxidase at 438 and 595 nm but did not show absorption peaks specific for c-type cytochrome. The optimum pH of molybdenum oxidase was 5.5. The activity of molybdenum oxidase was completely inhibited by sodium cyanide (5 mM) or carbon monoxide, and an oxidized type of cytochrome oxidase in a purified molybdenum oxidase was reduced by molybdenum blue, indicating that cytochrome oxidase in the enzyme plays a crucial role in molybdenum blue oxidation. 相似文献
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