Publications

polyamine distributions in thermophilic eubacteria belonging to thermus and acidothermus.	triamines such as norspermidine, spermidine, and homospermidine and tetraamines such as norspermine, spermine, thermospermine, and aminopropylhomospermidine were found to be distributed ubiquitously in the eight extremely thermophilic (growing at 70 degrees c) thermus species tested. three linear pentaamine (caldopentamine, homocaldopentamine, and thermopentamine), two linear hexaamines (caldohexamine and homocaldohexamine), two tertiary branched tetraamines (n4-aminopropylnorspermidine and n4-a ...	1991	1880132
molecular phylogeny of the genus frankia and related genera and emendation of the family frankiaceae.	the members of the actinomycete genus frankia are nitrogen-fixing symbionts of may species of woody dicotyledonous plants belonging to eight families. several strains isolated from diverse actinorhizal plants growing in different geographical areas were used in this study. the phylogenetic relationships of these organisms and uncharacterized microsymbionts that are recalcitrant to isolation in pure culture were determined by comparing complete 16s ribosomal dna sequences. the resulting phylogene ...	1996	8573482
morphological, physiological, and molecular characterization of actinomycetes isolated from dry soil, rocks, and monument surfaces.	in an extended study on the biodiversity of rock-dwelling bacteria, the colony and cell morphology, physiology, protein patterns, and 16s rdna sequences of 17 bacterial strains isolated from different surfaces of rocks, stones, and monuments and from various geographical locations were characterized. all except one strain, which was found to be a bacillus, were members of the order actinomycetales. the majority of the strains either were closely related to geodermatophilus obscurus, which was al ...	1996	8661940
crystal structure of thermostable family 5 endocellulase e1 from acidothermus cellulolyticus in complex with cellotetraose.	the crystal structure of the catalytic domain of the thermostable endocellulase e1 from acidothermus cellulolyticus in complex with cellotetraose has been solved by multiple isomorphous replacement and refined at 2.4 a resolution to an r-factor of 0.18 (rfree = 0.24). e1cd is a member of the 4/7 superfamily of hydrolases, and as expected, its structure is an (alpha/beta)8 barrel, which constitutes a prototype for family 5-subfamily 1 cellulases. the cellotetraose molecule binds in a manner consi ...	1996	8718854
hydrolysis of cellulose using ternary mixtures of purified cellulases.	the saccharification of microcrystalline cellulose by reconstituted ternary mixtures of purified cellulases (one endoglucanase and two cellobiohydrolases) has been studied over the entire range of mixture compositions. ternary plots are used to compare the performance of five synthetic mixtures drawn from the cellulase systems of acidothermus cellulolyticus, trichoderma reesei, thermomonospora fusca, and thermotoga neapolitana. results reveal that at least one synthetic mixture utilizing enzymes ...	1998	9627391
a reca gene phylogenetic analysis confirms the close proximity of frankia to acidothermus.	the closer proximity of frankia and acidothermus cellulolyticus relative to the morphologically close geodermatophilus found previously was confirmed by resequencing the rrs gene of acidothermus cellulolyticus and the housekeeping gene, reca. the diagnostic sugar 2-o-methyl-d-mannose was detected only in frankia, while hopanoid lipids were present at high levels in both acidothermus and frankia.	2000	10758889
expression of acidothermus cellulolyticus endoglucanase e1 in transgenic tobacco: biochemical characteristics and physiological effects.	the expression of the acidothermus cellulolyticus endoglucanase e1 gene in transgenic tobacco (nicotiana tabacum) was examined in this study, where e1 coding sequence was transcribed under the control of a leaf specific rubisco small subunit promoter (tomato rbcs-3c). targeting the e1 protein to the chloroplast was established using a chloroplast transit peptide of rubisco small subunit protein (tomato rbcs-2a) and confirmed by immunocytochemistry. the e1 produced in transgenic tobacco plants wa ...	2000	10853268
4-methyl-7-thioumbelliferyl-beta-d-cellobioside: a fluorescent, nonhydrolyzable substrate analogue for cellulases.	the kinetics of cellulose binding and hydrolysis by cellulases is not well understood except at steady-state conditions. for use in studies of cellulase pre-steady-state and steady-state kinetics, we have prepared 4-methyl-7-thioumbelliferyl-beta-d-cellobioside (mus-cb), a ground-state nonhydrolyzable analogue of the fluorescent cellulase substrate 4-methylumbelliferyl-beta-d-cellobioside (mu-cb). mus-cb is not hydrolyzed by the catalytic domain of cellulase e1 from acidothermus cellulolyticus u ...	2002	11914092
exploration of cellulose surface-binding properties of acidothermus cellulolyticus cel5a by site-specific mutagenesis.	understanding the interactions between cellulases and cellulosic substrates is critical to the development of an efficient artificial cellulase system for conversion of biomass to sugars. we directed specific mutations to the interactive surface of the acidothermus cellulolyticus ei endoglucanase catalytic domain. the cellulose-binding domain is not translated in these mutants. amino acid mutations were designed either to change the surface charge of the protein or to modify the potential for hy ...	2002	12018255
effect of single active-site cleft mutation on product specificity in a thermostable bacterial cellulase.	mutation of a single active-site cleft tyrosyl residue to a glycyl residue significantly changes the mixture of products released from phosphoric acid-swollen cellulose (psc) by eicd, the catalytic domain of the endoglucanase-i from acidothermus cellulolyticus. the percentage of glucose in the product stream is almost 40% greater for the y245g mutant (and for an additional double mutant, y245g/q204a) than for the wild type enzyme. comparisons of results for digestion psc and of pretreated yellow ...	2002	12018266
expression and import of an active cellulase from a thermophilic bacterium into the chloroplast both in vitro and in vivo.	a bacterial thermostable cellulase, the endo-1,4-beta-d-glucanase e1 from acidothermus cellulolyticus, was imported into chloroplasts, and an active enzyme was recovered both in vitro and in vivo. precursor fusion proteins were synthesized with e1 or its catalytic domain, cd, fused to the transit peptide of ferredoxin or ribulose-bisphosphate carboxylase activase for stromal targeting. a spacer region of 1, 5 or 15 amino acids was included carboxy to the transit peptide. the efficiency of import ...	2003	12650616
energetics for displacing a single chain from the surface of microcrystalline cellulose into the active site of acidothermus cellulolyticus cel5a.	a series of molecular mechanics calculations were used to analyze the energetics for moving a single polysaccharide chain from the surface of microcrystalline cellulose into the binding cleft of the cel5a cellulase from acidothermus cellulolyticus. a build-up procedure was used to model the placement of a 12-residue oligosaccharide chain along the surface of the enzyme, using as a guide the four residues of the tetrasaccharide substrate co-crystallized with the protein in the crystallographic st ...	2003	14983081
assessing the phylogeny of frankia-actinorhizal plant nitrogen-fixing root nodule symbioses with frankia 16s rrna and glutamine synthetase gene sequences.	actinomycetes from the genus frankia induce nitrogen-fixing root nodules on actinorhizal plants in the "core rosid" clade of eudicots. reported here are nine partial frankia 16s rrna gene sequences including the first from host plants of the rosaceous genera cercocarpus and chamaebatia, 24 partial glutamine synthetase (gsi; glna) sequences from frankia in nodules of 17 of the 23 actinorhizal genera, and the partial glna sequence of acidothermus cellulolyticus. phylogenetic analyses of combined f ...	2004	15019614
effects of ammonia fiber explosion treatment on activity of endoglucanase from acidothermus cellulolyticus in transgenic plant.	a critical parameter affecting the economic feasibility of lignocellulosic bioconversion is the production of inexpensive and highly active cellulase enzymes in bulk quantity. a promising approach to reduce enzyme costs is to genetically transform plants with the genes of these enzymes, thereby producing the desired cellulases in the plants themselves. extraction and recovery of active proteins or release of active cellulase from the plants during bioconversion could have a significant positive ...	2004	15054226
analysis of the function of a hyperthermophilic endoglucanase from pyrococcus horikoshii that hydrolyzes crystalline cellulose.	a hyperthermophilic beta-1,4 endoglucanase was identified in pyrococcus horikoshii, a hyperthermophilic archaeon. in order to clarify the function of the protein in detail, structural and catalytic site studies were performed using protein engineering. by removing some of the c-terminal sequence of the orf of the endoglucanase (ph1171), two types of recombinant proteins were expressed from one orf, using escherichia coli. one exhibited endoglucanase activity, and the other did not. an sd-like se ...	2005	15375673
catalytically enhanced endocellulase cel5a from acidothermus cellulolyticus.	<when tyr245 in endocellulase cel5a from acidothermus cellulolyticus was changed to gly (y245g) by designed mutation, the value of ki for inhibition of the enzyme by the product cellobiose was increased more than 1480%. this reduction in product inhibition enabled the mutant enzyme (used in conjunction with trichoderma reesei cellobiohydrolase-i) to release soluble sugars from biomass cellulose at a rate as much as 40% greater than that achieved by the wild-type (wt) enzyme. the mutant was desig ...	2005	15917594
quadrisphaera granulorum gen. nov., sp. nov., a gram-positive polyphosphate-accumulating coccus in tetrads or aggregates isolated from aerobic granules.	a gram-positive bacterium, designated strain ag019(t), was isolated by micromanipulation from aerobic granules obtained from a laboratory-scale sequencing batch reactor. this isolate grew axenically as cocci clustered predominantly in tetrads, and was morphologically similar to the dominant organisms observed in the biomass. the morphology also resembled that of the tetrad-forming organisms commonly seen in activated sludge samples. strain ag019(t) was found to be an oxidase-negative, catalase-p ...	2005	16166665
optimization of acidothermus cellulolyticus endoglucanase (e1) production in transgenic tobacco plants by transcriptional, post-transcription and post-translational modification.	an attempt was made to obtain a high-level production of intact acidothermus cellulolyticus endoglucanase (e1) in transgenic tobacco plants. the e1 expression was examined under the control of the constitutive and strong mac promoter or light-inducible tomato rubisco small sub-unit (rbcs-3c) promoter with its original or alfalfa mosaic virus (amv) rna4 5'-untranslated leader (utl) and targeted to different sub-cellular compartments via transit peptides. the transit peptides included native e1, e ...	2005	16245154
expression and characterization of acidothermus cellulolyticus e1 endoglucanase in transgenic duckweed lemna minor 8627.	endoglucanase e1 from acidothermus cellulolyticus was expressed cytosolically under control of the cauliflower mosaic virus 35s promoter in transgenic duckweed, lemna minor 8627 without any obvious observable phenotypic effects on morphology or rate of growth. the recombinant enzyme co-migrated with the purified catalytic domain fraction of the native e1 protein on western blot analysis, revealing that the cellulose-binding domain was cleaved near or in the linker region. the duckweed-expressed ...	2007	17127051
enhanced conversion of plant biomass into glucose using transgenic rice-produced endoglucanase for cellulosic ethanol.	the catalytic domain of acidothermus cellulolyticus thermostable endoglucanase gene (encoding for endo-1,4-beta-glucanase enzyme or e1) was constitutively expressed in rice. molecular analyses of t1 plants confirmed presence and expression of the transgene. the amount of e1 enzyme accounted for up to 4.9% of the plant total soluble proteins, and its accumulation had no apparent deleterious effects on plant growth and development. approximately 22 and 30% of the cellulose of the ammonia fiber exp ...	2007	17237981
subcellular targeting is a key condition for high-level accumulation of cellulase protein in transgenic maize seed.	ethanol from lignocellulosic biomass is being pursued as an alternative to petroleum-based transportation fuels. to succeed in this endeavour, efficient digestion of cellulose into monomeric sugar streams is a key step. current production systems for cellulase enzymes, i.e. fungi and bacteria, cannot meet the cost and huge volume requirements of this commodity-based industry. transgenic maize (zea mays l.) seed containing cellulase protein in embryo tissue, with protein localized to the endoplas ...	2007	17614952
genomic analysis reveals widespread occurrence of new classes of copper nitrite reductases.	recently, the structure of a cu-containing nitrite reductase (nir) from hyphomicrobium denitrificans (hdnir) has been reported, establishing the existence of a new family of cu-nir where an additional type 1 cu (t1cu) containing cupredoxin domain is located at the n-terminus (nojiri et al. in proc. natl. acad. sci. usa 104:4315-4320, 2007). hdnir retains the well-characterised coupled t1cu-type 2 cu (t2cu) core, where the t2cu catalytic site is also built utilising ligands from neighbouring mono ...	2007	17712582
heterologous acidothermus cellulolyticus 1,4-beta-endoglucanase e1 produced within the corn biomass converts corn stover into glucose.	commercial conversion of lignocellulosic biomass to fermentable sugars requires inexpensive bulk production of biologically active cellulase enzymes, which might be achieved through direct production of these enzymes within the biomass crops. transgenic corn plants containing the catalytic domain of acidothermus cellulolyticus e1 endo-1,4-beta glucanase and the bar bialaphos resistance coding sequences were generated after biolistic (biorad hercules, ca) bombardment of immature embryo-derived ce ...	2007	18478390
hydrolysis of cellulose using ternary mixtures of purified celluloses.	the saccharification of microcrystalline cellulose by reconstituted ternary mixtures of purified cellulases (one endoglucanase and two cellobiohydrolases) has been studied over the entire range of mixture compositions. ternary plots are used to compare the performance of five synthetic mixtures drawn from the cellulase systems of acidothermus cellulolyticus, trichoderma reesei, thermomonospora fusca, and thermotoga neapolitana. results reveal that at least one synthetic mixture utilizing enzymes ...	1998	18576007
fodinicola feengrottensis gen. nov., sp. nov., an actinomycete isolated from a medieval mine.	a filamentous, gram-positive actinobacterium was isolated from acidic rocks in a medieval alum slate mine and was investigated by means of a polyphasic taxonomic approach. a 16s rrna gene sequence similarity study indicated that strain hki 0501(t) forms an individual line of descent and is related to certain members of the suborder frankineae, order actinomycetales (<95 % sequence similarity). distance-matrix and neighbour-joining analyses set the branching point of the novel isolate between two ...	2008	18599689
complete genome of the cellulolytic thermophile acidothermus cellulolyticus 11b provides insights into its ecophysiological and evolutionary adaptations.	we present here the complete 2.4-mb genome of the cellulolytic actinobacterial thermophile acidothermus cellulolyticus 11b. new secreted glycoside hydrolases and carbohydrate esterases were identified in the genome, revealing a diverse biomass-degrading enzyme repertoire far greater than previously characterized and elevating the industrial value of this organism. a sizable fraction of these hydrolytic enzymes break down plant cell walls, and the remaining either degrade components in fungal cel ...	2009	19270083
expression of acidothermus cellulolyticus e1 endo-beta-1,4-glucanase catalytic domain in transplastomic tobacco.	as part of an effort to develop transgenic plants as a system for the production of lignocellulose-degrading enzymes, we evaluated the production of the endo-beta-1,4-glucanase e1 catalytic domain (e1cd) of acidothermus cellulolyticus in transplastomic tobacco. in an attempt to increase the translation efficiency of the e1cd cassette, various lengths of the n-terminus of the psba gene product were fused to the e1cd protein. the psba gene of the plastid genome encodes the d1 polypeptide of photos ...	2009	19500296
an l-arabinose isomerase from acidothermus cellulolytics atcc 43068: cloning, expression, purification, and characterization.	the araa gene encoding an l-arabinose isomerase (l-ai) from the acido-thermophilic bacterium acidothermus cellulolytics atcc 43068 was cloned and overexpressed in escherichia coli. the open reading frame of the l-ai consisted of 1,503 nucleotides encoding 501 amino acid residues. the recombinant l-ai was purified to homogeneity by heat treatment, ion-exchange chromatography, and gel filtration. the molecular mass of the enzyme was estimated to be approximately 55 kda by sodium dodecyl sulfate-po ...	2010	19921180
switchgrass leaching requirements for solid-state fermentation by acidothermus cellulolyticus.	growth of acidothermus cellulolyticus in solid-state fermentation and its required growth conditions were investigated in this study. extraction of switchgrass was required for growth. under the experimental conditions, extraction ratio had the most significant effect on the growth of a. cellulolyticus. heat treatment (in the form of autoclaving) of switchgrass did not have a significant effect on the growth rate; however, longer heat treatment times had a negative effect on the total growth. mo ...	2010	20039375
qm/mm study on the catalytic mechanism of cellulose hydrolysis catalyzed by cellulase cel5a from acidothermus cellulolyticus.	cellulase cel5a from acidothermus cellulolyticus is an endoglucanase which features the retention mechanism for the cleavage of the beta-1,4-glycosidic bond. in this work, we investigated the detailed catalytic steps in the formation of two cellobiose units from the hydrolysis of a cellotetraose molecule using a combined qm/mm approach. the understanding of the catalysis process at the atomistic level may help further protein engineering research. molecular dynamics, potentials of mean force (pm ...	2010	20041728
identification of a hemerythrin-like domain in a p1b-type transport atpase.	the p(1b)-type atpases couple the energy of atp hydrolysis to metal ion translocation across cell membranes. important for prokaryotic metal resistance and essential metal distribution in eukaryotes, p(1b)-atpases are divided into subclasses on the basis of their metal substrate specificities. sequence analysis of putative p(1b-5)-atpases, for which the substrate has not been identified, led to the discovery of a c-terminal soluble domain homologous to hemerythrin (hr) proteins and domains. the ...	2010	20672819
heterologous expression and extracellular secretion of cellulolytic enzymes by zymomonas mobilis.	development of the strategy known as consolidated bioprocessing (cbp) involves the use of a single microorganism to convert pretreated lignocellulosic biomass to ethanol through the simultaneous production of saccharolytic enzymes and fermentation of the liberated monomeric sugars. in this report, the initial steps toward achieving this goal in the fermentation host zymomonas mobilis were investigated by expressing heterologous cellulases and subsequently examining the potential to secrete these ...	2010	20693448
xyn10a, a thermostable endoxylanase from acidothermus cellulolyticus 11b.	we cloned and purified the major family 10 xylanase (xyn10a) from acidothermus cellulolyticus 11b. xyn10a was active on oat spelt and birchwood xylans between 60°c and 100°c and between ph 4 and ph 8. the optimal activity was at 90°c and ph 6; specific activity and k(m) for oat spelt xylan were 350 μmol xylose produced min⁻¹ mg of protein⁻¹ and 0.53 mg ml⁻¹, respectively. based on xylan cleavage patterns, xyn10a is an endoxylanase, and its half-life at 90°c was approximately 1.5 h in the presenc ...	2010	20851989
effects of phenolic monomers on growth of acidothermus cellulolyticus.	previous studies on biological pretreatment of switchgrass by solid-state fermentation with acidothermus cellulolyticus 11b have shown that inhibitory compounds prevent growth on untreated switchgrass. a. cellulolyticus was grown in liquid medium containing cellobiose with phenolic monomers added to determine if the phenolic compounds are one possible source of inhibition. cinnamic acid derivatives (trans-p-coumaric, trans-ferulic, and hydrocinnamic acids), hydroxybenzoic acids (p-hydroxybenzoic ...	2010	21181988
production and characterization of acidothermus cellulolyticus endoglucanase in pichia pastoris.	the endoglucanase (e1) from acidothermus cellulolyticus has been used extensively in cellulase research. the goal of this work was to produce high levels of this enzyme in a system that facilitates purification. a codon-optimized synthetic gene for a. cellulolyticus e1 with a c-terminal histidine tag was cloned into the genome of pichia pastoris. strain km71h expressed the most enzyme, with a yield of 550mg/l culture supernatant. the temperature optimum (80°c) and ph optimum (5.1) of the purifie ...	2011	21262363
in planta expression of a. cellulolyticus cel5a endocellulase reduces cell wall recalcitrance in tobacco and maize.	the glycoside hydrolase family 5 endocellulase, e1 (cel5a), from acidothermus cellulolyticus was transformed into both nicotiana tabacum and zea mays with expression targeted to the cell wall under a constitutive promoter. here we explore the possibility that in planta expression of endocellulases will allow these enzymes to access their substrates during cell wall construction, rendering cellulose more amenable to pretreatment and enzyme digestion. tobacco and maize plants were healthy and deve ...	2011	21269444
effects of phenolic monomers on growth of acidothermus cellulolyticus.	previous studies on biological pretreatment of switchgrass by solid-state fermentation with acidothermus cellulolyticus 11b have shown that inhibitory compounds prevent growth on untreated switchgrass. a. cellulolyticus was grown in liquid medium containing cellobiose with phenolic monomers added to determine if the phenolic compounds are one possible source of inhibition. cinnamic acid derivatives (trans-p-coumaric, trans-ferulic, and hydrocinnamic acids), hydroxybenzoic acids (p-hydroxybenzoic ...	2010	21312351
selection of conditions for cellulase and xylanase extraction from switchgrass colonized by acidothermus cellulolyticus.	solid-state fermentation has been widely used for enzyme production. however, secreted enzymes often bind to the solid substrate preventing their detection and recovery. a series of screening studies was performed to examine the role of extraction buffer composition including nacl, ethylene glycol, sodium acetate buffer, and tween 80, on xylanase and cellulase recovery from switchgrass. our results indicated that the selection of an extraction buffer is highly dependent on the nature and source ...	2011	21318368
peptide bond formation by aminolysin-a catalysis: a simple approach to enzymatic synthesis of diverse short oligopeptides and biologically active puromycins.	a new s9 family aminopeptidase derived from the actinobacterial thermophile acidothermus cellulolyticus was cloned and engineered into a transaminopeptidase by site-directed mutagenesis of catalytic ser(491) into cys. the engineered biocatalyst, designated aminolysin-a, can catalyze the formation of peptide bonds to give linear homo-oligopeptides, hetero-dipeptides, and cyclic dipeptides using cost-effective substrates in a one-pot reaction. aminolysin-a can recognize several c-terminal-modified ...	2011	21321761
high level expression of acidothermus cellulolyticus beta-1, 4-endoglucanase in transgenic rice enhances the hydrolysis of its straw by cultured cow gastric fluid.	abstract: background: large-scale production of effective cellulose hydrolytic enzymes is the key to bioconversion of agricultural residues to ethanol. the goal of this study was to develop rice plant as a bioreactor for large-scale production of cellulose hydrolytic enzymes via genetic transformation and to improve rice straw simultaneously as an efficient biomass feedstock for conversion of cellulose to glucose. results: in this study, the cellulose hydrolytic enzyme beta-1, 4-endoglucanase ( ...	2011	22152050
biodiversity characterization of cellulolytic bacteria present on native chaco soil by comparison of ribosomal rna genes.	sequence analysis of the 16s ribosomal rna gene was used to study bacterial diversity of a pristine forest soil and of two cultures of the same soil enriched with cellulolytic bacteria. our analysis revealed high bacterial diversity in the native soil sample, evidencing at least 10 phyla, in which actinobacteria, proteobacteria and acidobacteria accounted for more than 76% of all sequences. in both enriched samples, members of proteobacteria were the most frequently represented. the majority of ...	2011	22202170