Extremophiles : life under extreme conditions最新文献_第7页

Characteristics of thermostable endoxylanase and β-xylosidase of the extremely thermophilic bacterium Geobacillus thermodenitrificans TSAA1 and its applicability in generating xylooligosaccharides and xylose from agro-residues. 极热嗜热细菌热反硝化地杆菌TSAA1耐热性内聚糖酶和β-木糖苷酶的特性及其在农业残基制备低聚木糖和木糖中的应用

IF 2.9

Extremophiles : life under extreme conditions Pub Date : 2013-05-01 Epub Date: 2013-03-16 DOI: 10.1007/s00792-013-0524-x

Ashima Anand, Vikash Kumar, T Satyanarayana

{"title":"Characteristics of thermostable endoxylanase and β-xylosidase of the extremely thermophilic bacterium Geobacillus thermodenitrificans TSAA1 and its applicability in generating xylooligosaccharides and xylose from agro-residues.","authors":"Ashima Anand, Vikash Kumar, T Satyanarayana","doi":"10.1007/s00792-013-0524-x","DOIUrl":"https://doi.org/10.1007/s00792-013-0524-x","url":null,"abstract":"An extremely thermophilic bacterial isolate that produces a high titer of thermostable endoxylanase and β-xylosidase extracellularly in an inducible manner was identified as Geobacillus thermodenitrificans TSAA1. The distinctive features of this strain are alkalitolerance and halotolerance. The endoxylanase is active over a broad range of pH (5.0-10.0) and temperatures (30-100 °C) with optima at pH 7.5 and 70 °C, while β-xylosidase is optimally active at pH 7.0 and 60 °C. The T 1/2 values of the endoxylanase and β-xylosidase are 30 min at 80 °C, and 180 min at 70 °C, respectively. The endoxylanase activity is stimulated by dithiothreitol, but inhibited strongly by EDAC and Woodward's reagent K. N-BS and DEPC strongly inhibited β-xylosidase. MALDI-ToF (MS/MS) analysis of tryptic digest of β-xylosidase revealed similarity with that of G. thermodenitrificans NG 80-2, and suggested that this belongs to the GH 52 glycosyl hydrolase super family. The action of endoxylanase on birch wood xylan and agro-residues such as wheat bran and wheat straw liberated xylooligosaccharides similar to endoxylanases of the family 10 glycoside hydrolases, while the enzyme preparation having both endoxylanase and β-xylosidase liberated xylose as main hydrolysis product.","PeriodicalId":288153,"journal":{"name":"Extremophiles : life under extreme conditions","volume":" ","pages":"357-66"},"PeriodicalIF":2.9,"publicationDate":"2013-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s00792-013-0524-x","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"31315612","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: 54

Lipid storage in high-altitude Andean Lakes extremophiles and its mobilization under stress conditions in Rhodococcus sp. A5, a UV-resistant actinobacterium. 高海拔安第斯湖极端微生物的脂质储存及其在抗紫外线放线菌红球菌A5胁迫条件下的动员

IF 2.9

Extremophiles : life under extreme conditions Pub Date : 2013-03-01 Epub Date: 2013-01-03 DOI: 10.1007/s00792-012-0508-2

Susana Bequer Urbano, Virginia H Albarracín, Omar F Ordoñez, María E Farías, Héctor M Alvarez

{"title":"Lipid storage in high-altitude Andean Lakes extremophiles and its mobilization under stress conditions in Rhodococcus sp. A5, a UV-resistant actinobacterium.","authors":"Susana Bequer Urbano, Virginia H Albarracín, Omar F Ordoñez, María E Farías, Héctor M Alvarez","doi":"10.1007/s00792-012-0508-2","DOIUrl":"https://doi.org/10.1007/s00792-012-0508-2","url":null,"abstract":"The production of triacylglycerols (TAG) or wax esters (WS) seems to be a widespread feature among extremophile bacteria living in high-altitude Andean Lakes (HAAL), Argentina. Twelve out of twenty bacterial strains isolated from HAAL were able to produce TAG or WS (between 2 and 17 % of cellular dry weight) under nitrogen-limiting culture conditions. Among these strains, the extremophile Rhodococcus sp. A5 accumulated significant amounts of TAG during growth on glucose (17 %, CDW) and hexadecane (32 %, CDW) as sole carbon sources. The role of accumulated TAG in the response to carbon starvation, osmotic stress, UV-radiation and desiccation was investigated in Rhodococcus sp. A5 using an inhibitor of TAG degradation. Cells degraded TAG during these stresses in the absence of the inhibitor. The inhibition of TAG mobilization affected cell survival during osmotic stress only during the initial growth stage. Little or no surviving cells were observed after carbon starvation, UV-treatment and desiccation, when TAG mobilization was inhibited. These results suggested that TAG metabolism is relevant for the adaptation and survival of A5 cells under carbon starvation, osmotic stress and UV irradiation, and essential under desiccation conditions, which prevail in HAAL environments.","PeriodicalId":288153,"journal":{"name":"Extremophiles : life under extreme conditions","volume":" ","pages":"217-27"},"PeriodicalIF":2.9,"publicationDate":"2013-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s00792-012-0508-2","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40205573","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: 46

Unraveling the function of paralogs of the aldehyde dehydrogenase super family from Sulfolobus solfataricus. 石竹醛脱氢酶超家族类似物功能的揭示。

IF 2.9

Extremophiles : life under extreme conditions Pub Date : 2013-03-01 Epub Date: 2013-01-08 DOI: 10.1007/s00792-012-0507-3

D Esser, T Kouril, F Talfournier, J Polkowska, T Schrader, C Bräsen, B Siebers

{"title":"Unraveling the function of paralogs of the aldehyde dehydrogenase super family from Sulfolobus solfataricus.","authors":"D Esser, T Kouril, F Talfournier, J Polkowska, T Schrader, C Bräsen, B Siebers","doi":"10.1007/s00792-012-0507-3","DOIUrl":"https://doi.org/10.1007/s00792-012-0507-3","url":null,"abstract":"Aldehyde dehydrogenases (ALDHs) have been well established in all three domains of life and were shown to play essential roles, e.g., in intermediary metabolism and detoxification. In the genome of Sulfolobus solfataricus, five paralogs of the aldehyde dehydrogenases superfamily were identified, however, so far only the non-phosphorylating glyceraldehyde-3-phosphate dehydrogenase (GAPN) and α-ketoglutaric semialdehyde dehydrogenase (α-KGSADH) have been characterized. Detailed biochemical analyses of the remaining three ALDHs revealed the presence of two succinic semialdehyde dehydrogenase (SSADH) isoenzymes catalyzing the NAD(P)(+)-dependent oxidation of succinic semialdehyde. Whereas SSO1629 (SSADH-I) is specific for NAD(+), SSO1842 (SSADH-II) exhibits dual cosubstrate specificity (NAD(P)(+)). Physiological significant activity for both SSO-SSADHs was only detected with succinic semialdehyde and α-ketoglutarate semialdehyde. Bioinformatic reconstructions suggest a major function of both enzymes in γ-aminobutyrate, polyamine as well as nitrogen metabolism and they might additionally also function in pentose metabolism. Phylogenetic studies indicated a close relationship of SSO-SSALDHs to GAPNs and also a convergent evolution with the SSADHs from E. coli. Furthermore, for SSO1218, methylmalonate semialdehyde dehydrogenase (MSDH) activity was demonstrated. The enzyme catalyzes the NAD(+)- and CoA-dependent oxidation of methylmalonate semialdehyde, malonate semialdehyde as well as propionaldehyde (PA). For MSDH, a major function in the degradation of branched chain amino acids is proposed which is supported by the high sequence homology with characterized MSDHs from bacteria. This is the first report of MSDH as well as SSADH isoenzymes in Archaea.","PeriodicalId":288153,"journal":{"name":"Extremophiles : life under extreme conditions","volume":" ","pages":"205-16"},"PeriodicalIF":2.9,"publicationDate":"2013-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s00792-012-0507-3","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40218724","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: 19

Multifunctional enzymes in archaea: promiscuity and moonlight. 古细菌中的多功能酶:滥交和月光。

IF 2.9

Extremophiles : life under extreme conditions Pub Date : 2013-03-01 Epub Date: 2013-01-03 DOI: 10.1007/s00792-012-0509-1

Baolei Jia, Gang-Won Cheong, Shihong Zhang

引用次数: 28

Properties of the endogenous components of the thioredoxin system in the psychrophilic eubacterium Pseudoalteromonas haloplanktis TAC 125. 嗜冷嗜盐假异单胞菌TAC 125中硫氧还蛋白系统内源组分的性质。

IF 2.9

Extremophiles : life under extreme conditions Pub Date : 2012-05-01 Epub Date: 2012-04-22 DOI: 10.1007/s00792-012-0453-0

Patrizia Falasca, Giovanna Evangelista, Roberta Cotugno, Salvatore Marco, Mariorosario Masullo, Emmanuele De Vendittis, Gennaro Raimo

{"title":"Properties of the endogenous components of the thioredoxin system in the psychrophilic eubacterium Pseudoalteromonas haloplanktis TAC 125.","authors":"Patrizia Falasca, Giovanna Evangelista, Roberta Cotugno, Salvatore Marco, Mariorosario Masullo, Emmanuele De Vendittis, Gennaro Raimo","doi":"10.1007/s00792-012-0453-0","DOIUrl":"https://doi.org/10.1007/s00792-012-0453-0","url":null,"abstract":"The endogenous components of the thioredoxin system in the Antarctic eubacterium Pseudoalteromonas haloplanktis have been purified and characterised. The temperature dependence of the activities sustained by thioredoxin (PhTrx) and thioredoxin reductase (PhTrxR) pointed to their adaptation in the cold growth environment. PhTrxR was purified as a flavoenzyme and its activity was significantly enhanced in the presence of molar concentration of monovalent cations. The energetics of the partial reactions leading to the whole electron transfer from NADPH to the target protein substrate in the reconstituted thioredoxin system was also investigated. While the initial electron transfer from NADPH to PhTrxR was energetically favoured, the final passage to the heterologous protein substrate enhanced the energetic barrier of the whole process. The energy of activation of the heat inactivation process essentially reflected the psychrophilic origin of PhTrxR. Vice versa, PhTrx possessed an exceptional heat resistance (half-life, 4.4 h at 95 °C), ranking this protein among the most thermostable enzymes reported so far in psychrophiles. PhTrxR was covalently modified by glutathione, mainly by its oxidised or nitrosylated forms. A mutagenic analysis realised on three non catalytic cysteines of the flavoenzyme allowed the identification of C(303) as the target for the S-glutathionylation reaction.","PeriodicalId":288153,"journal":{"name":"Extremophiles : life under extreme conditions","volume":" ","pages":"539-52"},"PeriodicalIF":2.9,"publicationDate":"2012-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s00792-012-0453-0","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40176987","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: 12

The amino acid composition of proteins from anaerobic halophilic bacteria of the order Halanaerobiales. 厌氧嗜盐菌蛋白质的氨基酸组成。

IF 2.9

Extremophiles : life under extreme conditions Pub Date : 2012-05-01 Epub Date: 2012-04-19 DOI: 10.1007/s00792-012-0455-y

Rahel Elevi Bardavid, Aharon Oren

{"title":"The amino acid composition of proteins from anaerobic halophilic bacteria of the order Halanaerobiales.","authors":"Rahel Elevi Bardavid, Aharon Oren","doi":"10.1007/s00792-012-0455-y","DOIUrl":"https://doi.org/10.1007/s00792-012-0455-y","url":null,"abstract":"We performed a comparative analysis of the genome sequences of three anaerobic halophilic fermentative bacteria belonging to the order Halanaerobiales: Halanaerobium praevalens, the alkaliphilic \"Halanaerobium hydrogeniformans\", and the thermophilic Halothermothrix orenii to assess the amino acid composition of their proteins. Members of the Halanaerobiales were earlier shown to accumulate KCl rather than organic compatible solutes for osmotic balance, and therefore the presence of a dominantly acidic proteome was predicted. Past reports indeed showed a large excess of acidic over basic amino acids in whole-cell hydrolysates of selected members of the order. However, the genomic analysis did not show unusually high contents of acidic amino acids or low contents of basic amino acids. The apparent excess of acidic amino acids in these anaerobic halophiles reported earlier is due to the high content in their proteins of glutamine and asparagine, which yield glutamate and aspartate upon acid hydrolysis. It is thus suggested that the proteins of the Halanaerobiales, which are active in the presence of high intracellular KCl concentrations, do not possess the typical acidic signature of the 'halophilic' proteins of the Archaea of the order Halobacteriales or of the extremely halophilic bacterium Salinibacter.","PeriodicalId":288153,"journal":{"name":"Extremophiles : life under extreme conditions","volume":" ","pages":"567-72"},"PeriodicalIF":2.9,"publicationDate":"2012-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s00792-012-0455-y","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40176989","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: 34

Three nth homologs are all required for efficient repair of spontaneous DNA damage in Deinococcus radiodurans. 耐辐射球菌自发DNA损伤的有效修复需要三个n个同源物。

IF 2.9

Extremophiles : life under extreme conditions Pub Date : 2012-05-01 Epub Date: 2012-04-21 DOI: 10.1007/s00792-012-0447-y

Xiaoting Hua, Xin Xu, Mingfeng Li, Chao Wang, Bing Tian, Yuejin Hua

{"title":"Three nth homologs are all required for efficient repair of spontaneous DNA damage in Deinococcus radiodurans.","authors":"Xiaoting Hua, Xin Xu, Mingfeng Li, Chao Wang, Bing Tian, Yuejin Hua","doi":"10.1007/s00792-012-0447-y","DOIUrl":"https://doi.org/10.1007/s00792-012-0447-y","url":null,"abstract":"Deinococcus radiodurans is a bacterium that can survive extreme DNA damage. To understand the role of endonuclease III (Nth) in oxidative repair and mutagenesis, we constructed nth single, double and triple mutants. The nth mutants showed no significant difference with wild type in both IR resistance and H(2)O(2) resistance. We characterized these strains with regard to mutation rates and mutation spectrum using the rpoB/Rif(r) system. The Rif(r) frequency of mutant MK1 (△dr0289) was twofold higher than that of wild type. The triple mutant of nth (ME3)generated a mutation frequency 34.4-fold, and a mutation rate 13.8-fold higher than the wild type. All strains demonstrated specific mutational hotspots. Each single mutant had higher spontaneous mutation frequency than wild type at base substitution (G:C → A:T). The mutational response was further increased in the double and triple mutants. The higher mutation rate and mutational response in ME3 suggested that the three nth homologs had non-overlapped and overlapped substrate spectrum in endogenous oxidative DNA repair.","PeriodicalId":288153,"journal":{"name":"Extremophiles : life under extreme conditions","volume":" ","pages":"477-84"},"PeriodicalIF":2.9,"publicationDate":"2012-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s00792-012-0447-y","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40176516","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: 10

Sequence fingerprints of enzyme specificities from the glycoside hydrolase family GH57. 糖苷水解酶GH57家族酶特异性的序列指纹图谱。

IF 2.9

Extremophiles : life under extreme conditions Pub Date : 2012-05-01 Epub Date: 2012-04-22 DOI: 10.1007/s00792-012-0449-9

Karol Blesák, Stefan Janeček

{"title":"Sequence fingerprints of enzyme specificities from the glycoside hydrolase family GH57.","authors":"Karol Blesák, Stefan Janeček","doi":"10.1007/s00792-012-0449-9","DOIUrl":"https://doi.org/10.1007/s00792-012-0449-9","url":null,"abstract":"The glycoside hydrolase family 57 (GH57) contains five well-established enzyme specificities: α-amylase, amylopullulanase, branching enzyme, 4-α-glucanotransferase and α-galactosidase. Around 700 GH57 members originate from Bacteria and Archaea, a substantial number being produced by thermophiles. An intriguing feature of family GH57 is that only slightly more than 2 % of its members (i.e., less than 20 enzymes) have already been biochemically characterized. The main goal of the present bioinformatics study was to retrieve from databases, and analyze in detail, sequences having clear features of the five GH57 enzyme specificities mentioned above. Of the 367 GH57 sequences, 56 were evaluated as α-amylases, 99 as amylopullulanases, 158 as branching enzymes, 46 as 4-α-glucanotransferases and 8 as α-galactosidases. Based on the analysis of collected sequences, sequence logos were created for each specificity and unique sequence features were identified within the logos. These features were proposed to define the so-called sequence fingerprints of GH57 enzyme specificities. Domain arrangements characteristic of the individual enzyme specificities as well as evolutionary relationships within the family GH57 are also discussed. The results of this study could find use in rational protein design of family GH57 amylolytic enzymes and also in the possibility of assigning a GH57 specificity to a hypothetical GH57 member prior to its biochemical characterization.","PeriodicalId":288153,"journal":{"name":"Extremophiles : life under extreme conditions","volume":" ","pages":"497-506"},"PeriodicalIF":2.9,"publicationDate":"2012-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s00792-012-0449-9","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40176518","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: 50

Use of Raman spectroscopy for identification of compatible solutes in halophilic bacteria. 用拉曼光谱法鉴定嗜盐细菌中相容溶质。

IF 2.9

Extremophiles : life under extreme conditions Pub Date : 2012-05-01 Epub Date: 2012-04-20 DOI: 10.1007/s00792-012-0450-3

Jan Jehlička, Aharon Oren, Petr Vítek

{"title":"Use of Raman spectroscopy for identification of compatible solutes in halophilic bacteria.","authors":"Jan Jehlička, Aharon Oren, Petr Vítek","doi":"10.1007/s00792-012-0450-3","DOIUrl":"https://doi.org/10.1007/s00792-012-0450-3","url":null,"abstract":"We explored the use of Raman spectroscopy to detect organic osmotic solutes as biomarkers in the moderately halophilic heterotrophic bacterium Halomonas elongata grown in complex medium (accumulation of glycine betaine) and in defined medium with glucose as carbon source (biosynthesis of ectoine), and in the anoxygenic phototrophic Ectothiorhodospira marismortui known to synthesize glycine betaine in combination with minor amounts of trehalose and N-α-carbamoyl glutamineamide. We tested different methods of preparation of the material: lyophilization, two-phase extraction of water-soluble molecules, and perchlorate extraction. Raman signals of glycine betaine and ectoine were detected; perchlorate extraction followed by desalting the extract on an ion retardation column gave the best results. Lyophilized cells of E. marismortui showed strong signals of carotenoid pigments, and glycine betaine could be detected only after perchlorate extraction and desalting. The data presented show that Raman spectroscopy is a suitable tool to assess the mode of osmotic adaptation used by halophilic microorganisms.","PeriodicalId":288153,"journal":{"name":"Extremophiles : life under extreme conditions","volume":" ","pages":"507-14"},"PeriodicalIF":2.9,"publicationDate":"2012-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s00792-012-0450-3","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40176985","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: 25

Cloning and expression of acidstable, high maltose-forming, Ca2+-independent α-amylase from an acidophile Bacillus acidicola and its applicability in starch hydrolysis. 嗜酸芽孢杆菌耐酸、高麦芽糖生成、Ca2+不依赖性α-淀粉酶的克隆、表达及其在淀粉水解中的应用

Extremophiles : life under extreme conditions Pub Date : 2012-05-01 Epub Date: 2012-04-18 DOI: 10.1007/s00792-012-0451-2

Archana Sharma, T Satyanarayana

引用次数: 0