| haloalkaliphilic maltotriose-forming alpha-amylase from the archaebacterium natronococcus sp. strain ah-36. | a haloalkaliphilic archaebacterium, natronococcus sp. strain ah-36, produced extracellularly a maltotriose-forming amylase. the amylase was purified to homogeneity by ethanol precipitation, hydroxylapatite chromatography, hydrophobic chromatography, and gel filtration. the molecular weight of the enzyme was estimated to be 74,000 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. the amylase exhibited maximal activity at ph 8.7 and 55 degrees c in the presence of 2.5 m nacl. the activ ... | 1992 | 1592801 |
| [nucleotide composition and homologies in the dna of new extreme halophilic soil archaebacteria]. | dna nucleotide composition was studied in extreme halophilic bacteria belonging to the genera halobacterium, halococcus, natronobacterium and natronococcus. the cultures were shown to be a monolithic group of microorganisms with the content of gc pairs typical of extreme halophilic archebacteria. the difference between the content of dna major and minor components was twice as high in halobacterium distributus strains isolated from sulfate saline soils as compared to cultures of this species iso ... | 1987 | 3449743 |
| cloning, expression, and nucleotide sequence of the alpha-amylase gene from the haloalkaliphilic archaeon natronococcus sp. strain ah-36. | the alpha-amylase gene of a natronococcus sp. (1,512 bp) contained a signal peptide of 43 amino acids. haloferax volcanii expressed the gene and cleaved the signal peptide accurately. the signal peptide shared an extremely high amino acid sequence identity with that of a protease from the halophilic archaeon 172p1. | 1994 | 8051028 |
| biochemistry of s-layers. | during evolution prokaryotes have developed different envelope structures exterior to the cell wall proper. among these surface components are regularly arranged s-layers and capsules. the structural characterization and the detailed chemical analysis of these surface molecules is a prerequisite to understand their biosynthesis and functional role(s) at the molecular level. of particular interest are the glycosylated s-layer proteins which belong to the first prokaryotic glycoproteins ever descr ... | 1997 | 9276927 |
| detection and preliminary characterization of extracellular proteolytic activities of the haloalkaliphilic archaeon natronococcus occultus. | extracellular proteolytic activity was detected in the haloalkaliphilic archaeon natronococcus occultus as the culture reached the stationary growth phase. proteolytic activity was precipitated with ethanol and subjected to a preliminary characterization. optimal conditions for activity were attained at 60 degrees c and 1-2 m nacl or kcl. gelatin zymography in the presence of 4 m betaine revealed a complex pattern of active species with apparent molecular masses ranging from 50 to 120 kda. exper ... | 1997 | 9385146 |
| the cell wall polymer of the extremely halophilic archaeon natronococcus occultus. | the cell wall polymer of natronococcus occultus (dsm 3396) consists of l-glutamate, n-acetyl-d-glucosamine, n-acetyl-d-galactosamine, d-galacturonic acid, d-glucuronic acid and d-glucose in a molar ratio of 5:7:1:8:0.5:0.3. partial acid hydrolysis of the cell wall polymer produced soluble fragments that could be separated by hplc. a gamma-glutamyl dipeptide was isolated. in the intact cell wall polymer, the glutamate residues form a poly-(gamma-glutamine) chain with a length of about 60 monomers ... | 1997 | 9395342 |
| extracellular protease of natrialba magadii: purification and biochemical characterization. | a serine protease secreted by the haloalkaliphilic archaeon natrialba magadii at the end of the exponential growth phase was isolated. this enzyme was purified 83 fold with a total yield of 25% by ethanol precipitation, affinity chromatography, and gel filtration. the native molecular mass of the enzyme determined by gel filtration was 45 kda. na. magadii extracellular protease was dependent on high salt concentrations for activity and stability, and it had an optimum temperature of 60 degrees c ... | 2000 | 10879563 |
| purification and biochemical characterization of the haloalkaliphilic archaeon natronococcus occultus extracellular serine protease. | a serine protease was purified from natronococcus occultus stationary phase culture medium (328-fold, yield 19%) and characterized at the biochemical level. the enzyme has a native molecular mass of 130 kda, has chymotrypsin-like activity, is stable and active in a broad ph range (5.5-12), is rather thermophilic (optimal activity at 60 degrees c in 1-2 m nacl) and is dependent on high salt concentrations for activity and stability (1-2 m nacl or kcl). polyclonal antibodies were raised against th ... | 2001 | 11802548 |
| comparison of euryarchaea strains in the guts and food-soil of the soil-feeding termite cubitermes fungifaber across different soil types. | termites are an important component of tropical soil communities and have a significant effect on the structure and nutrient content of soil. digestion in termites is related to gut structure, gut physicochemical conditions, and gut symbiotic microbiota. here we describe the use of 16s rrna gene sequencing and terminal-restriction fragment length polymorphism (t-rflp) analysis to examine methanogenic archaea (ma) in the guts and food-soil of the soil-feeder cubitermes fungifaber sjostedt across ... | 2004 | 15240259 |
| [analysis of partial sequence of the gene for a novel br protein]. | a strain of halophilic archaeum ab1 was isolated and purified from aibi lake located in the north of xinjiang uygur autonomous region. partial dna fragment encoding a bacteriorhodopsin (br) protein as well as 16s rrna of ab1 was amplified by pcr, and their nucleotide sequences were determined subsequently. on the basis of homology and phylognetic analysis about 16s rrna gene (16s rdna), it could be speculated that the strain ab1 is a novel member of the genus natronococcus. the hydropathy analys ... | 2004 | 15640016 |
| [archaeal diversity of zabuye lake in tibet analyzed by culture-independent approach]. | with culture-independent approach, microbial dna was directly extracted from samples of zabuye saline soda lake. using the microbial dna as template, archaeal 16s rdnas were amplified by pcr. amplified products were cloned and sequenced. 60 different cloned partial sequences, most of which were related to haloalkaliphilic archaeon, were acquired. in the phylogenetic tree, some clones of zabuye lake belonged to genus natronobacterium, natrinema, natronococcus, natronorubrum, natronomonas, halorub ... | 2003 | 16276911 |
| phylogenetic relationships within the order halobacteriales inferred from 16s rrna gene sequences. | phylogenetic relationships within the halophilic archaea were inferred from comparisons of the 16s rrna gene sequences from 61 strains, representing 18 genera with validly published names within the order halobacteriales. trees produced using distance-matrix (least-squares and neighbour-joining) methods affirm with strong bootstrap support that the members of the order halobacteriales are a monophyletic group. ten genera were supported as monophyletic groups [haloarcula, halobiforma, halococcus, ... | 2006 | 16738095 |
| halovivax ruber sp. nov., an extremely halophilic archaeon isolated from lake xilinhot, inner mongolia, china. | a gram-negative, pleomorphic, extremely halophilic archaeon, designated strain xh-70(t), was isolated from the saline lake xilinhot, in inner mongolia, china. it formed small (0.9-1.5 mm), red-pigmented, elevated colonies on agar medium. the strain required at least 2.5 m nacl and 5 mm mg(2+) for growth. the 16s rrna gene sequence analysis indicated that strain xh-70(t) belongs to the family halobacteriaceae, showing 99.5 % similarity to the type strain of halovivax asiaticus and 94.7 and 94.6 % ... | 2007 | 17473252 |
| analysis of yeast and archaeal population dynamics in kimchi using denaturing gradient gel electrophoresis. | kimchi is a traditional korean food that is fermented from vegetables such as chinese cabbage and radish. many bacteria are involved in kimchi fermentation and lactic acid bacteria are known to perform significant roles. although kimchi fermentation presents a range of environmental conditions that could support many different archaea and yeasts, their molecular diversity within this process has not been studied. here, we use pcr-denaturing gradient gel electrophoresis (dgge) targeting the 16s a ... | 2008 | 18562030 |
| natronoarchaeum mannanilyticum gen. nov., sp. nov., an aerobic, extremely halophilic archaeon isolated from commercial salt. | strain ysm-123(t) was isolated from commercial salt made from japanese seawater in niigata prefecture. optimal nacl and mg(2+) concentrations for growth were 4.0-4.5 m and 5 mm, respectively. the isolate was a mesophilic and slightly alkaliphilic haloarchaeon, whose optimal growth temperature and ph were 37 °c and ph 8.0-9.0. phylogenetic analysis based on 16s rrna gene sequence analysis suggested that strain ysm-123(t) is a member of the phylogenetic group defined by the family halobacteriaceae ... | 2010 | 19965994 |
| archaeal diversity in the haloalkaline lake elmenteita in kenya. | a non-culture approach was used to study the archaeal diversity in lake elmenteita, kenya. five different sampling points were selected randomly within the lake. wet sediments and water samples were collected from each sampling point. in addition, dry mud cake was collected from three points where the lake had dried. dna was extracted from these samples and the 16s rrna genes were amplified using primers described to be domain-specific for archaea. eleven clone libraries were constructed using p ... | 2010 | 19806396 |
| phylogenetic analysis of the archaeal community in an alkaline-saline soil of the former lake texcoco (mexico). | the soil of the former lake texcoco is an extreme environment localized in the valley of mexico city, mexico. it is highly saline and alkaline, where na+, cl(-), hco3(-) and co3(2-) are the predominant ions, with a ph ranging from 9.8 to 11.7 and electrolytic conductivities in saturation extracts from 22 to 150 ds m(-1). metagenomic dna from the archaeal community was extracted directly from soil and used as template to amplify 16s ribosomal gene by pcr. pcr products were used to construct gene ... | 2008 | 18097633 |
| diversity of halophilic archaea from six hypersaline environments in turkey. | the diversity of archaeal strains from six hypersaline environments in turkey was analyzed by comparing their phenotypic characteristics and 16s rdna sequences. thirty-three isolates were characterized in terms of their phenotypic properties including morphological and biochemical characteristics, susceptibility to different antibiotics, and total lipid and plasmid contents, and finally compared by 16s rdna gene sequences. the results showed that all isolates belong to the family halobacteriacea ... | 2007 | 18050917 |
| phylogenetic relationships within the family halobacteriaceae inferred from rpob' gene and protein sequences. | in order to clarify the current phylogeny of the haloarchaea, particularly the closely related genera that have been difficult to sort out using 16s rrna gene sequences, the dna-dependent rna polymerase subunit b' gene (rpob') was used as a complementary molecular marker. partial sequences of the gene were determined from 16 strains of the family halobacteriaceae. comparisons of phylogenetic trees inferred from the gene and protein sequences as well as from corresponding 16s rrna gene sequences ... | 2007 | 17911299 |
| natronococcus jeotgali sp. nov., a halophilic archaeon isolated from shrimp jeotgal, a traditional fermented seafood from korea. | a novel halophilic archaeon (strain b1(t)) belonging to the genus natronococcus was isolated from shrimp jeotgal, a traditional fermented food from korea. colonies of this strain were orange-red and cells were non-motile cocci that stained gram-variable. strain b1(t) grew in 7.5-30.0 % (w/v) nacl and at 21-50 degrees c and ph 7.0-9.5, with optimal growth occurring in 23-25 % (w/v) nacl and at 37-45 degrees c and ph 7.5. strain b1(t) was most closely related to the type strain of natronococcus oc ... | 2007 | 17766885 |
| control of ribosome turnover during growth of the haloalkaliphilic archaeon natronococcus occultus. | the metabolism of ribosomes during growth of the haloalkaliphilic archaeon natronococcus occultus was examined. the ribosome content was higher during exponential growth and diminished to 35% of the maximum in the stationary stage. the incorporation of h3-orotic acid and c14-uracil into rrna was higher during exponential growth. after that, it decreased to 39% of the maximum in the stationary stage. the labeling of non-ribosomal rna took place almost exclusively in the exponential stage. from lo ... | 2006 | 16814992 |
| halovivax asiaticus gen. nov., sp. nov., a novel extremely halophilic archaeon isolated from inner mongolia, china. | strain ej-46t, a novel pleomorphic, aerobic, extremely halophilic member of the archaea was isolated from sediment of the saline lake ejinor, in inner mongolia, china. this organism was neutrophilic and required at least 15 % (2.5 m) nacl for growth. mgcl2 was not required. the isolate was able to grow at ph 6.0-9.0. optimum growth occurred in media containing 20 % (3.4 m) nacl at ph 7.0-7.5. polar lipid analysis revealed the presence of phosphatidylglycerol and phosphatidylglycerol phosphate me ... | 2006 | 16585691 |
| [diversity of halophilic archaea in hypersaline lakes of inner mongolia, china]. | the aims of this work were to explore the diversity of halophilic archaea in hypersaline lakes of inner mongolia, china and to collect novel halophilic archaea. one hundred and sixty-five halophilic archaea were isolated from the three different types of hypersaline lakes (erliannor, shangmatala and xilin soda lake) in inner mongolia. by analysis of the restriction patterns of amplified 16s rdna (ardra) with the enzyme afa i and hae ii, respectively, the isolates were clustered into 14 genotypes ... | 2006 | 16579455 |
| lysis of halobacteria in bacto-peptone by bile acids. | all tested strains of halophilic archaebacteria of the genera halobacterium, haloarcula, haloferax, and natronobacterium lysed in 1% bacto-peptone (difco) containing 25% nacl, whereas no lysis was observed with other strains belonging to archaebacteria of the genera halococcus, natronococcus, and sulfolobus, methanogenic bacteria, and moderately halophilic eubacteria. substances in bacto-peptone which caused lysis of halobacteria were purified and identified as taurocholic acid and glycocholic a ... | 1988 | 16347619 |
| lipolytic activity from halobacteria: screening and hydrolase production. | strains of halobacteria from an algerian culture collection were screened for their lipolytic activity against p-nitrophenyl butyrate (pnpb) and p-nitrophenyl palmitate (pnpp). most strains were active on both esters and 12% hydrolyzed olive oil. a strain identified as natronococcus sp. was further studied. it grew optimally at 3.5 m nacl, ph 8 and 40 degrees c. an increase in temperature shifted the optimum salt concentration range for growth from a wider range of 2-4 m, obtained at 25-30 degre ... | 2005 | 15979821 |
| detection of quorum sensing signals in the haloalkaliphilic archaeon natronococcus occultus. | bacteria communicate at high cell density through quorum sensing, however, there are no reports about this mechanism in archaea. the archaeon natronococcus occultus produces an extracellular protease at the end of growth. early production of protease activity was observed when a low density culture was incubated with late exponential conditioned medium suggesting the presence of factor(s) inducing this activity. conditioned medium and ethyl acetate extracts corresponding to the transition from e ... | 2003 | 12694909 |
| characterization of a novel halophilic archaeon, halobiforma haloterrestris gen. nov., sp. nov., and transfer of natronobacterium nitratireducens to halobiforma nitratireducens comb. nov. | strain 135(t), a novel red-pigmented, aerobic, extremely halophilic member of the archaea showing rod, coccus and slightly pleomorphic morphology, was isolated from hypersaline soil close to aswan (egypt). this organism is neutrophilic, motile and requires at least 2.2 m nacl, but no mgcl2, for growth and exhibits optimal growth at 42 degrees c. polar lipid analysis revealed the presence of sulfated triglycosyl diether and triglycosyl diether as the sole glycolipids as well as the absence of the ... | 2002 | 12508897 |
| diversity of archaea in hypersaline environments characterized by molecular-phylogenetic and cultivation studies. | the diversity of archaea from three different hypersaline environments was analyzed and compared by polymerase chain reaction (pcr)-based molecular phylogenetic techniques and cultivation approaches. the samples originated from a crystallization pond of a solar saltern in spain (fc); an alkaline lake in nevada, usa, (emf); and a small pond from a slag heap of a potassium mine in germany (die). except for two 16s rdna sequences that were related to crenarchaeota from soil and did not apparently b ... | 2002 | 12215811 |
| ubiquitin-like proteins in halobacteria. | within our studies of protein degradation, the presence of ubiquitinylated proteins in haloalkaliphilic archaea was investigated. we found that natronococcus occultus proteins that react with antibodies raised against ubiquitin appear in different growth phases, particularly in the initial and exponential ones. the expression of these proteins is increased when the cells are either treated with puromycin or starved for nutrients. dot blot analysis of cell extracts with antibody against ubiquitin ... | 2002 | 12210552 |
| autoproteolytic activation of the haloalkaliphilic archaeon natronococcus occultus extracellular serine protease. | the haloalkaliphilic archaeon natronococcus occultus produces an extracellular serine protease in the stationary growth phase and upon starvation. two proteins immunologically related to the extracellular protease were detected into the cells: p200 and p190. p200 was detected at early stages of growth and its relative amount decreased as the culture reached the stationary growth phase, concomitantly with the appearance of p190 and proteolytic activity, suggesting that p200 may be the precursor o ... | 2001 | 11802542 |
| purification and characterization of a membrane-associated atpase from natronococcus occultus, a haloalkaliphilic archaeon. | isolated membranes of the extreme haloalkaliphilic archaeon natronococcus occultus were able to hydrolyze atp via an atpase, which required the presence of mg(2+), high concentrations of nacl, and a ph value of 9. the native molecular mass of the purified atpase was 130 kda and was composed of 74- and 61-kda subunits. enzyme activity was specific for the hydrolysis of atp with slight activity towards gtp, ctp, and itp. the enzyme required nacl for maximal activity but na(2)so(4) and (nh(4))(2)so ... | 2000 | 10930740 |
| amylase and 16s rrna genes from a hyperthermophilic archaebacterium. | a hyperthermophilic and amylolytic prokaryote, designated rt3, was isolated from a thermal spring near rotorua, new zealand. the 16s rrna gene of rt3 was cloned and sequenced with the aim of determining its phylogenetic affiliations. the phylogenetic analysis of this sequence, which included a selection of archaebacterial and eubacterial 16s rrna sequences, indicates that rt3 most likely belongs to the archaebacterial order thermococcales. an amylase gene (amya) from rt3, encoding a highly therm ... | 1999 | 10030014 |
| 2-sulfotrehalose, a novel osmolyte in haloalkaliphilic archaea. | a novel 1-->1 alpha-linked glucose disaccharide with sulfate at c-2 of one of the glucose moieties, 1-(2-o-sulfo-alpha-d-glucopyranosyl)-alpha-d-glycopyranose, was found to be the major organic solute accumulated by a natronococcus sp. and several natronobacterium species. the concentration of this novel disaccharide, termed sulfotrehalose, increased with increasing concentrations of external nacl, behavior consistent with its identity as an osmolyte. a variety of noncharged disaccharides (treha ... | 1997 | 9150208 |
| on the revised structure of the major phospholipid of halobacterium salinarium. | recent fast atom bombardment-mass spectrometry (fabms) studies (tsujimoto, k., yorimitsu, s., takahashi, t. and ohashi, m. (1989) j. chem. commun. 668-670; frederickson, h.l., de leeuw, j.w., tas, a.c., van der greef, j., lavos, g.f. and boon, j.j. (1989) biomed. environ. mass. spectrom. 18, 96-105; kloppel, k.d. and fredrickson, h.l. (1991) j. chromatogr. 562, 369-376) have indicated that the structure of the major phospholipid of halobacterium salinarium (formerly halobacterium cutirubrum) is ... | 1993 | 8334149 |
| natronococcus amylolyticus sp. nov., a haloalkaliphilic archaeon. | the alpha-amylase-producing haloalkaliphilic archaeon natronococcus sp. strain ah-36t (t = type strain) was isolated previously from a kenyan soda lake, lake magadi. most cells of strain ah-36t occurred in irregular clusters, and the colonies were orange-red. the polar lipids of this organism were composed of c20, c20 and c20, c25 derivatives of phosphatidylglycerol and phosphatidylglycerophosphate. phosphatidylglycero-(cyclo-) phosphate, which is characteristic of natronococcus occultus, was no ... | 1995 | 7547296 |
| fast atom bombardment mass spectrometry as a rapid means of screening mixtures of ether-linked polar lipids from extremely halophilic archaebacteria for the presence of novel chemical structures. | fast atom bombardment mass spectrometry was used to analyse intact polar ether lipids present at microgram levels in crude lipid mixtures extracted from halobacterium halobium, natronococcus occultus and halobacterium marismortui. negative-ion spectra showed the intact deprotonated lipid molecules and in some instances their sodium salts. the simplicity of the mass spectra permits the rapid screening of polar lipid mixtures for the presence of novel lipids. additional structural information of i ... | 1991 | 1902842 |
| biosorption and bio-kinetic studies of halobacterial strains against ni(2+), al(3+) and hg(2+) metal ions. | the present study is an attempt to find out the promising metal (ni(2+), al(3+), and hg(2+)) biosorbant halobacterial strains from saltern pan and to study their biokinetic parameters for metal recovery. of the selected 65 isolates, natronobacterium magadii, natronococcus occultus and halobacterium sodomense shows the maximum metal resistance activity against ni(2+) (250ppm), al(3+) (600ppm) and hg(2+) (25ppm) metals. biokinetic parameters such as maximum specific growth rate (μ(max)), substrate ... | 2011 | 22217730 |
| intracellular proteolytic activity of the haloalkaliphilic archaeon natronococcus occultus. effect of starvation. | intracellular proteolytic activity was detected in the haloalkaliphilic archaeon natronococcus occultus during the stationary phase of cultures grown in complete medium and during carbon and nitrogen starvation. puromycin prevented the occurrence of proteolytic activity in starved cells, suggesting that de novo synthesis of proteolytic enzymes might be required for protein degradation during starvation. intracellular proteolytic activity degraded casein and gelatin. it had a temperature optimum ... | 1997 | 22145190 |
| identification of polyhydroxyalkanoates in halococcus and other haloarchaeal species. | polyhydroxyalkanoates (phas) are accumulated in many prokaryotes. several members of the halobacteriaceae produce poly-3-hydroxybutyrate (phb), but it is not known if this is a general property of the family. we evaluated identification methods for phas with 20 haloarchaeal species, three of them isolates from permian salt. staining with sudan black b, nile blue a, or nile red was applied to screen for the presence of phas. transmission electron microscopy and (1)h-nuclear magnetic resonance spe ... | 2010 | 20437233 |