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51.
从武夷山的一枯枝上分离得到了一株稀有软骨霉状菌,在培养过程中发现,该株黏细菌在人工培养基上只有在与一种未知的细菌共培养的状态下才能长出典型的子实体并保持菌种的活力.然而要从共培养的菌落中纯化这株黏细菌,使用常规的黏细菌纯化技术几乎是不可能.在这种情况下对伴生细菌进行16SrDNA菌种鉴定,再根据鉴定为施氏假单胞菌(Ps... 相似文献
52.
Osamu Takimura Hiroyuki Fuse Katsuzi Murakami Kazuo Kamimura Yukiho Yamaoka 《应用有机金属化学》1996,10(9):753-756
Uptake and reduction of arsenate [AS(V)] by Dunaliella sp. cells were determined to investigate the metabolic processes of arsenic in the alga. Cellular uptake of arsenic by Dunaliella sp. cells was markedly affected by the form of arsenic in the medium. The content of arsenic taken up by Dunaliella sp. cells increased rapidly with time on addition of As(V) to the medium. However, in the case of addition of arsenite [As(III)], the gradient of arsenic uptake by Dunaliella sp. cells was low, and arsenic content was small. In the water-soluble fraction of arsenic taken up by Dunaliella sp. cells with exposure to As(V), arsenic was in the forms of organic arsenic, As(V) and As(III). The content of As(V) in the water-soluble fraction increased with exposure time. The content of As(III) also increased with time, but remained constant after 5 h of exposure. On the other hand, organic arsenic content was small and did not increase with time. It was found that Dunaliella sp. takes up As(V) and readily reduces it to As(III) 相似文献
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Karim Samy El-Said Shaimaa Hussein Barakat M. Alrashdi Heba A. Mahmoud Mahrous A. Ibrahim Mohamed Elbakry Hala El-Tantawy Doaa Ibrahim Kabil Sabry A. El-Naggar 《Molecules (Basel, Switzerland)》2022,27(2)
Heavy metals intoxication causes several health problems that necessitate finding new protective and therapeutic approaches. This study aimed to evaluate the impact of Musa sp. leaves extract (MLE) on hepato-renal toxicities induced by cadmium (Cd) in male mice. The phytochemical screening, metal chelating activity (MCA), and the median lethal dose (LD50) of MLE were determined. Fifty CD-1 male mice were used and intraperitoneally (i.p.) injected with MLE (1000 to 5000 mg/kg b.wt) for MLE LD50 determination. Another 50 mice were used for evaluating the effect of MLE on Cd toxicity. Blood samples were collected for hematological, liver, and kidney functions assessments. Liver tissue homogenates were used for determination of oxidant/antioxidant parameters. Liver and kidney tissues were harvested for histopathological and molecular investigations. MLE showed potent in vitro antioxidant activities. The MCA and LD50 of the MLE were 75 µg/mL and 3000 mg/kg b.wt, respectively. MLE showed beneficial therapeutic activity against hepato-renal toxicities in Cd-intoxicated mice, evidenced by improving the hematological, biochemical, histopathological, and molecular alterations. 相似文献
55.
通过对酶系组成和酶解条件的研究,得出了制备禾本科植物内生真菌Neotyphodiumsp.原生质体的最佳条件:鲜菌丝由10.3%蔗糖溶液预处理,酶系组成为1.5%崩溃酶、1.0%蜗牛酶、1.0%纤维素酶和2.0%溶菌酶,酶解温度32℃,pH 6.8,酶解5 h,原生质体得率达7.3×103个/mg鲜菌丝.另外,液体再生涂布平板法结合钙离子作用可使原生质体再生率达4.72%,为不含钙离子处理组的2.5倍. 相似文献
56.
Prakasham RS Rao ChS Rao RS Rajesham S Sarma PN 《Applied biochemistry and biotechnology》2005,120(2):133-144
Optimization of alkaline protease production parameters by Bacillus sp. was investigated using Taguchi methodology. The pH of the medium was observed to be the most significant factor among
all selected optimization parameters at an individual level. The combinatorial influence of least significant factors, inoculum
level and salt solution concentration (at the individual level), resulted in an interacting severity index of 76%, suggesting
their interactive role in the regulation of protease production in this microbial species. Protease production could be improved
more than 100% with Taguchi’s optimized conditions of the medium composition by this microorganism. 相似文献
57.
Kariate Sudhakara Prasad A. B. Arun P. D. Rekha Chiu‐Chung Young Jen‐Lin Chang Jyh‐Myng Zen 《Electroanalysis》2009,21(14):1646-1650
Aerobically grown Shewanella sp. bacterial suspension drop‐coated on a disposable screen‐printed carbon electrode was found to possess electroactivity without the aid of redox mediator. Cyclic voltammetric studies revealed the characteristics of a mixed diffusion adsorption‐controlled electrochemical process for direct electron transfer at the bacteria‐modified electrode. Both FE‐SEM and ATR FT‐IR experiments were carried out to investigate the surface characteristics. The electroanalytical applicability was further demonstrated for electrocatalytic reduction of arsenite, hydrogen peroxide and nitrite. Low cost and very simple manufacturing procedure allow for the proposed bacterial sensor to be applied as disposable devices. 相似文献
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不动杆菌静息细胞催化拆分外消旋环戊酮醇乙酸酯反应条件的优化 总被引:4,自引:0,他引:4
考察了反应条件对不动杆菌Acinetobactersp.YQ231催化外消旋环戊酮醇乙酸酯对映选择性水解的反应速度和对映选择性的影响.确定的最佳酶反应条件为pH8.0,温度50℃.不同乳化剂对对映选择性的影响不同,以壬基酚聚氧乙烯醚的效果最好,当其加入量为15g/L时,反应的对映选择性最高.产物环戊酮醇对酶活性有显著的抑制作用.细胞中的酯酶优先水解(R)-环戊酮醇乙酸酯,生成(R)-环戊酮醇,在底物浓度为250mmol/L时,对映体比率(E值)可达50. 相似文献