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51.
Purification of aquarium water by PVA gel-immobilized photosynthetic bacteria during goldfish rearing 总被引:1,自引:0,他引:1
Soo Kyong Jeong Jeong-Sup Cho In-Soo Kong Hyun Do Jeong Joong Kyun Kim 《Biotechnology and Bioprocess Engineering》2009,14(2):238-247
This study was conducted to evaluate the ability of a PVA-gel beads filtration (PVA) system using photosynthetic bacteria
to purify water. To accomplish this, duplicate long-term goldfish rearing experiments were conducted using four different
types of aquarium systems (COF, PSB, EMC, and PVA). The results revealed that the concentrations of NH4
+-N on the day of a goldfish’s death were significantly higher than the concentrations on other days for all the aquarium systems.
In addition, the mean concentration of NH4
+-N during goldfish rearing occurred in the following order: COF system > EMC system > PSB system > PVA system. Furthermore,
the mean values of all other ion concentrations (NO3
−-N, NO2
−-N, and PO4
2−-P) were found to be lowest in the PVA system. As a result, there was more prominent decomposition of organic matter in the
aquarium tank containing the PVA system, as well as less turbid aquarium water and more active goldfish. Additionally, the
PVA-gel beads resulted in almost complete denitrification, even after six-months of goldfish rearing. To our knowledge, this
is the first study to report that PVA gel-immobilized photosynthetic bacteria have the ability to purify water. Overall, the
results of this study indicate that this immobilized photosynthetic bacteria system has the potential for use as a component
in circulating filtration systems. 相似文献
52.
53.
The genome-wide screening of yeast deletion mutants to identify the genes required for tolerance to ethanol and other alcohols 总被引:1,自引:0,他引:1
A set of homozygous diploid deletion mutants of the yeast Saccharomyces cerevisiae was screened for the genes required for tolerance to aliphatic alcohols. The screen identified 137, 122 and 48 deletion mutants sensitive to ethanol, 1-propanol and 1-pentanol, respectively. A number of the genes required for ethanol tolerance were those also required for tolerance to other alcohols. Numerous mutants with defective genes encoding for vacuolar H+ -ATPase (V-ATPase) were cosensitive to these alcohols. A global screening approach of yeast deletion library mutants was useful in elucidating the mechanisms of alcohol tolerance based on different lipophilicities. 相似文献
54.
Levin I Meiri G Peretz M Burstein Y Frolow F 《Protein science : a publication of the Protein Society》2004,13(6):1547-1556
Pseudomonas aeruginosa alcohol dehydrogenase (PaADH; ADH, EC 1.1.1.1) catalyzes the reversible oxidation of primary and secondary alcohols to the corresponding aldehydes and ketones, using NAD as coenzyme. We crystallized the ternary complex of PaADH with its coenzyme and a substrate molecule and determined its structure at a resolution of 2.3 A, using the molecular replacement method. The PaADH tetramer comprises four identical chains of 342 amino acid residues each and obeys ~222-point symmetry. The PaADH monomer is structurally similar to alcohol dehydrogenase monomers from vertebrates, archaea, and bacteria. The stabilization of the ternary complex of PaADH, the coenzyme, and the poor substrate ethylene glycol (k(cat) = 4.5 sec(-1); Km > 200 mM) was due to the blocked exit of the coenzyme in the crystalline state, combined with a high (2.5 M) concentration of the substrate. The structure of the ternary complex presents the precise geometry of the Zn coordination complex, the proton-shuttling system, and the hydride transfer path. The ternary complex structure also suggests that the low efficiency of ethylene glycol as a substrate results from the presence of a second hydroxyl group in this molecule. 相似文献
55.
Mehriban Akin Merve Yuksel Caner Geyik Dilek Odaci Arne Bluma Tim Höpfner Sascha Beutel Thomas Scheper Suna Timur 《Biotechnology progress》2010,26(3):896-906
A highly stable and sensitive amperometric alcohol biosensor was developed by immobilizing alcohol oxidase (AOX) through Polyamidoamine (PAMAM) dendrimers on a cysteamine‐modified gold electrode surface. Ethanol determination is based on the consumption of dissolved oxygen content due to the enzymatic reaction. The decrease in oxygen level was monitored at ?0.7 V vs. Ag/AgCl and correlated with ethanol concentration. Optimization of variables affecting the system was performed. The optimized ethanol biosensor showed a wide linearity from 0.025 to 1.0 mM with 100 s response time and detection limit of (LOD) 0.016 mM. In the characterization studies, besides linearity some parameters such as operational and storage stability, reproducibility, repeatability, and substrate specificity were studied in detail. Stability studies showed a good preservation of the bioanalytical properties of the sensor, 67% of its initial sensitivity was kept after 1 month storage at 4°C. The analytical characteristics of the system were also evaluated for alcohol determination in flow injection analysis (FIA) mode. Finally, proposed biosensor was applied for ethanol analysis in various alcoholic beverage as well as offline monitoring of alcohol production through the yeast cultivation. © 2010 American Institute of Chemical Engineers Biotechnol. Prog., 2010 相似文献
56.
Wilson L Illanes A Pessela BC Abian O Fernández-Lafuente R Guisán JM 《Biotechnology and bioengineering》2004,86(5):558-562
The encapsulation of crosslinked enzyme aggregates (CLEA) of penicillin G acylase into a very rigid polymeric matrix based on polyvinyl alcohol (LentiKats) has been used successfully to improve the inadequate mechanical properties of CLEA. This encapsulation decreased CLEA activity by only around 40%. As compensation, a significant improvement in the stability of the CLEA in the presence of organic solvents was detected. This could be related to the highly hydrophilic environment inside the LentiKats biocatalysts: Partition experiments showed that the concentration of dioxane inside LentiKats was lower than in the reaction medium. In fact, thermal stability was about the same as in the corresponding CLEA. This permitted great improvement in the reaction rate for thermodynamically controlled synthesis of a model antibiotic (using phenylacetic acid and 7-amino-deacetoxycefalosporanic acid). Even more importantly, yields could be improved by using LentiKats-encapsulated CLEA, very likely by a favorable product/substrate partition. Thus, this very simple technique not only provides an efficient technique for solving the mechanical stability problem associated with CLEA, but also greatly improves the behavior of CLEA in organic media. 相似文献
57.
Ignacio R. Rodriguez Pedro Gonzales J. Samuel Zigler Teresa Borrás 《生物化学与生物物理学报:疾病的分子基础》1992,1180(1):44-52
A congenital cataract present in guinea pigs provided a unique opportunity to study a hereditary lens diseases at the molecular level. ζ-crystallin, one of the most abundant guinea pig lens proteins, was found to be altered in the lens of cataractous animals. Several ζ-crystallin cDNA clones were isolated from a cataractous lens library and found to contain a 102-bp deletion towards the 3′ end of the coding region. The deletion does not interfere with the reading frame but results in a protein 34 amino acids shorter. Sequence analysis of a normal genomic ζ-crystallin clone revealed that the missing 102-bp fragment corresponds to an entire exon (exon 7). PCR analysis of the genomic DNA isolated from cataractous animals showed that exon 7, though missing from the mRNA, is intact in the cataractous genome. Further sequence analysis of the α-crystallin gene disclosed a dinucleotide delection of the universal AG at the acceptor splice-site of intron 6 of the mutant gene. The presence of this mutation results in the skipping of exon 7 during the mRNA processing which in turn results in the altered ζ-crystallin protein. This if the first time a genomic mutation in an enzyme/crytallin gene has been directly linked to a congenital cataract. 相似文献
58.
Kai-Fu Chang Hung-Chih Lai Shan-Chih Lee Xiao-Fan Huang Ya-Chih Huang Tien-Erh Chou Chih-Yen Hsiao Nu-Man Tsai 《Journal of cellular and molecular medicine》2023,27(10):1423-1435
Melanoma is a highly metastatic cancer with a low incidence rate, but a high mortality rate. Patchouli alcohol (PA), a tricyclic sesquiterpene, is considered the main active component in Pogostemon cablin Benth, which improves wound healing and has anti-tumorigenic activity. However, the pharmacological action of PA on anti-melanoma remains unclear. Thus, the present study aimed to investigate the role of PA in the proliferation, cell cycle, apoptosis and migration of melanoma cells. These results indicated that PA selectively inhibited the proliferation of B16F10 cells in a dose- and time-dependent manner. It induced cell cycle arrest at the G0/G1 phase and typical morphological changes in apoptosis, such as chromatin condensation, DNA fragmentation and apoptotic bodies. In addition, PA reduced the migratory ability of B16F10 cells by upregulating E-cadherin and downregulating p-Smad2/3, vimentin, MMP-2 and MMP-9 expression. PA was also found to strongly suppress tumour growth in vivo. Furthermore, PA combined with cisplatin synergistically inhibited colony formation and migration of B16F10 cells and attenuated the development of resistance to treatment. Therefore, the results of this study indicate that PA may play a pivotal role in inducing apoptosis and reducing the migration of melanoma cells, and may thus be a potential candidate for melanoma treatment. 相似文献
59.
研究了向日葵茎芯中主要活性物质多糖的提取工艺,并对此工艺进行了优化,选取的提取方法为水提醇沉法,以多糖含量作为指标,采用单因素试验研究了提取次数、原料颗粒的大小(目数)、料液比、提取时间、提取温度对向日葵茎芯多糖含量的影响。用苯酚-硫酸法测定提取液中多糖的含量,得出向日葵茎芯中多糖的最佳提取工艺条件为:提取次数2次,原料颗粒的大小(目数)60~80目,料液比(g·mL-1)1:50,提取时间3.0 h,提取温度90℃,在最优提取条件下,多糖的提取得率为6.56%,多糖的含量为266.03 mg·g-1。本文也对多糖的体外抗肿瘤活性进行了研究,结果表明向日葵茎芯多糖的体外抗肿瘤活性较弱。这些条件的确定为向日葵茎芯的深入研究奠定了基础。 相似文献
60.