Journal of Fermentation and Bioengineering最新文献_第9页

Site-directed mutagenesis of histidine residues in the ethylene-forming enzyme from Pseudomonas syringae 丁香假单胞菌乙烯形成酶组氨酸残基的定点突变

Journal of Fermentation and Bioengineering Pub Date : 1998-01-01 DOI: 10.1016/S0922-338X(97)85671-1

Kazuhiro Nagahama , Kuniaki Yoshino , Masayoshi Matsuoka , Sumio Tanase , Takahira Ogawa , Hideo Fukuda

{"title":"Site-directed mutagenesis of histidine residues in the ethylene-forming enzyme from Pseudomonas syringae","authors":"Kazuhiro Nagahama , Kuniaki Yoshino , Masayoshi Matsuoka , Sumio Tanase , Takahira Ogawa , Hideo Fukuda","doi":"10.1016/S0922-338X(97)85671-1","DOIUrl":"10.1016/S0922-338X(97)85671-1","url":null,"abstract":"<div>The roles of histidine residues in the catalysis of the transformation of 2-oxoglutarate into ethylene via the ethylene-forming enzyme (EFE) from Pseudomonas syringae were studied using site-directed mutagenesis with substitution of glutamine for ten individual histidine residues. The mutant enzymes, which were expressed in Escherichia coli, were purified to homogeneity, and assayed in vitro for Km, kcat and thermostability. The relative kcat of two mutated EFEs, H305Q and H335Q, were 40% and 60%, respectively. However, a mutation at either His-189 or His-233 caused a total loss of activity, implying that these residues play important roles in the binding of iron. The kcat values for other mutant enzymes were 11-to 55-fold less than that for the wild-type enzyme. For six partially inactive mutated EFEs (but not for H305Q or H335Q), the first order rate constants for heat inactivation at 30°C were 11-to 24-fold higher than for the wild-type enzyme. It is noteworthy that the value of the first order rate constant for heat inactivation of H268Q was identical to that of H335Q. The substitution of H268 resulted in a drastic decrease of the kcat value (relative kcat was 1.8%). This suggests that the substitution at His-268 may cause the disruption of the active site of the EFE. Heat inactivation studies with the puridied mutant enzymes revealed that some mutant enzymes, such as H168Q and H116Q, were more thermolabile than the wild-type enzyme.</div>","PeriodicalId":15696,"journal":{"name":"Journal of Fermentation and Bioengineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1998-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0922-338X(97)85671-1","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77595666","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 13

Asymmetric reduction of methyl 3-oxopentanoate by Chlorella 小球藻对3-氧戊酸甲酯的不对称还原

Journal of Fermentation and Bioengineering Pub Date : 1998-01-01 DOI: 10.1016/S0922-338X(98)80091-3

Fumiki Yoshizako, Takayuki Kuramoto, Atsuo Nishimura, Mitsuo Chubachi

引用次数: 9

High Production of Pyoluteorin and 2, 4-Diacetylphloroglucinol by Pseudomonas fluorescens S272 Grown on Ethanol as a Sole Carbon Source 以乙醇为唯一碳源培养荧光假单胞菌S272高产吡咯啉和2,4 -二乙酰间苯三酚

Journal of Fermentation and Bioengineering Pub Date : 1998-01-01 DOI: 10.1016/S0922-338X(99)80006-3

Zhan Yuan, S. Cang, M. Matsufuji, K. Nakata, Y. Nagamatsu, A. Yoshimoto

引用次数: 44

An approach to high-level production of cephalosporin acylase from Pseudomonas strain N176 in Escherichia coli 假单胞菌N176在大肠杆菌中高效生产头孢菌素酰化酶的途径

Journal of Fermentation and Bioengineering Pub Date : 1998-01-01 DOI: 10.1016/S0922-338X(98)80019-6

Yuji Noguchi, Hisashi Yamada, Michitaka Yamaguchi, Katsuyuki Watanabe, Takao Fujimura, Yoshinori Ishii, Yoshimasa Saito

引用次数: 1

Excretion of glycerol by the marine Chlamydomonas sp. strain W-80 in high CO2 cultures 海洋衣藻属菌株W-80在高CO2培养中的甘油排泄

Journal of Fermentation and Bioengineering Pub Date : 1998-01-01 DOI: 10.1016/S0922-338X(97)80367-4

Hitoshi Miyasaka , Yosuke Ohnishi , Toru Akano , Kiyomi Fukatsu , Tadashi Mizoguchi , Kiyohito Yagi , Isamu Maeda , Yoshiaki Ikuta , Hiroyo Matsumoto , Norio Shioji , Yoshiharu Miura

引用次数: 32

Effect of acetic and butyric acids on the stability of solvent and spore formation by Clostridium acetobutylicum ATCC 824 during repeated subculturing 乙酸和丁酸对醋酸丁酸梭菌ATCC 824反复传代培养过程中溶剂稳定性和孢子形成的影响

Journal of Fermentation and Bioengineering Pub Date : 1998-01-01 DOI: 10.1016/S0922-338X(97)86769-4

Omar Assobhei , Abdellah El Kanouni , Mohammed Ismaili , Mohammed Loutfi , Henri Petitdemange

引用次数: 28

A dense cell culture system for aerobic microorganisms using a shaken ceramic membrane flask with surface aeration 一种使用带有表面曝气的摇摇陶瓷膜烧瓶的好氧微生物密集细胞培养系统

Journal of Fermentation and Bioengineering Pub Date : 1998-01-01 DOI: 10.1016/S0922-338X(97)86771-2

Yuya Kamoshita, Ryo Ohashi, Takahiro Suzuki

{"title":"A dense cell culture system for aerobic microorganisms using a shaken ceramic membrane flask with surface aeration","authors":"Yuya Kamoshita, Ryo Ohashi, Takahiro Suzuki","doi":"10.1016/S0922-338X(97)86771-2","DOIUrl":"10.1016/S0922-338X(97)86771-2","url":null,"abstract":"<div>Aeration of the head space in a shaken ceramic membrane flask (SCM flask) capped with a cotton plug was found to be essential for increasing cell concentration and viability of aerobic microorganisms. Ventilation through the cotton plug cap was insufficient for satisfying the oxygen demand of aerobically growing cells in the SCM flask. Dissolved oxygen concentration (DO) in the culture supernatant of Escherichia coli in batch culture using the SCM flask dropped to nearly 0 ppm when the cell concentration reached 1 g/l, while CO2 concentration in the head space of the SCM flask increased quickly to nearly 20% owing to accumulation of the evolved CO2. In contrast, the oxygen transfer coefficient in a SCM flask shaken at 230 rpm was as high as 220 h−1, compared to that in a stirred type jar fermentor. Consequently, aeration of the head space of the SCM flask was found to be sufficient for supplying oxygen by vigorous waves created in the culture broth due to the reciprocal shaking action. Using the SCM flask, E. coli cell mass reached 84 g/l in 40 h with aeration of the head space with oxygen-enriched gas. The SCM flask with aeration to the head space enabled an increase in the concentration and productivity of viable cells to be readily achieved by continuously replenishing the culture supernatant with oxygen in conjunction with the removal of the evolved CO2.</div>","PeriodicalId":15696,"journal":{"name":"Journal of Fermentation and Bioengineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1998-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0922-338X(97)86771-2","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74438828","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 11

Analysis of acclimation behavior against nitrification inhibitors in activated sludge processes 活性污泥法对硝化抑制剂的驯化行为分析

Journal of Fermentation and Bioengineering Pub Date : 1998-01-01 DOI: 10.1016/S0922-338X(98)80115-3

Xiaojing Xiong, Makoto Hirata, Hirokazu Takanashi, Min-Gyu Lee , Tadashi Hano

引用次数: 12

Key word index 关键词索引

Journal of Fermentation and Bioengineering Pub Date : 1998-01-01 DOI: 10.1016/S0922-338X(98)90013-7

引用次数: 0

Effect of ethanol on bacterial cellulose production from fructose in continuous culture 连续培养中乙醇对细菌从果糖中生产纤维素的影响

Journal of Fermentation and Bioengineering Pub Date : 1998-01-01 DOI: 10.1016/S0922-338X(98)80012-3

Takaaki Naritomi, Tohru Kouda, Hisato Yano, Fumihiro Yoshinaga

{"title":"Effect of ethanol on bacterial cellulose production from fructose in continuous culture","authors":"Takaaki Naritomi, Tohru Kouda, Hisato Yano, Fumihiro Yoshinaga","doi":"10.1016/S0922-338X(98)80012-3","DOIUrl":"10.1016/S0922-338X(98)80012-3","url":null,"abstract":"<div>Effect of ethanol on bacterial cellulose (BC) production from fructose by Acetobacter xylinum subsp. sucrofermentans BPR3001A was investigated in continuous culture. Supplementation of 10 g·l−1 ethanol to the feed medium containing 30 g·l−1 fructose as the main carbon source enhanced the ATP content of viable cells, cell concentration, and fructose consumption rate, establishing a 72-h steady state with 0.95 g·l−1·h−1 of BC production rate and 46% of BC yield in continuous culture with a dilution rate of 0.07 h−1. However, an increase in concentration of ethanol to more than 15 g·l−1 decreased BC production rate due to the inhibition of cell growth by the generated acetate. Results from batch culture experiment using ethanol as the main carbon source suggested that ethanol functioned as an energy source for ATP generation, and not as a substrate for BC biosynthesis. On the other hand, fructose hexokinase (FHK) activity was increased and activities of glucose 6-phosphate dehydrogenases (G6PDs) were inhibited by ATP, suggesting that the improved BC production from fructose by ethanol supplementation was a result of increased fructose dissimilation and abundant flow of glucose 6-phosphate (G6P), a precursor of BC, into the BC biosynthetic pathway due to the inhibition of G6PDs by increased levels of ATP.</div>","PeriodicalId":15696,"journal":{"name":"Journal of Fermentation and Bioengineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1998-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0922-338X(98)80012-3","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90612240","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 91