| studies on the rumen flagellate neocallimastix frontalis. | the vast increase in the population density of the rumen flagellate neocallimastix frontalis shortly after the host animal has commenced eating is caused by stimulation of a reproductive body on a vegetative phase of the organism to differentiate and liberate the flagellates. the stimulant is a component of the host's diet. the vegetative stage of n. frontalis bears a strong morphological resemblance to that of certain species of aquatic phycomycete fungi, and consists of a reproductive body bor ... | 1975 | 1462 |
| on the induction of zoosporogenesis in the rumen phycomycetes neocallimastix frontalis, piromonas communis and sphaeromonas communis. | the plant components inducing zoosporogenesis in the rumen phycomycetes neocallimastix frontalis, sphaeromonas communis and piromonas communis were widely distributed in the plant kingdom with no apparent taxonomic relationship. in lolium perenne l. (perennial rye-grass) and hordeum distichon (barley), the components were principally present in the leaves and aerial tissues. sufficient inducer was present in the normal diet of the host animal to trigger the differentiation and release of the zoo ... | 1977 | 21939 |
| invasion of plant tissue in the rumen by the flagellate neocallimastix frontalis. | the flagellate stage of the rumen phycomycete neocallimastix frontalis invades and germinates on plant material in the rumen and in vitro, preferentially invading the lemmas, paleas, awns and flower bracts in members of the plant family gramineae, and flower bracts in certain of the papilionaceae. the principal sites of invasion were the stomata and damaged tissue, through which penetration of the plant tissue by the rhizoid of the germinating cell occurred. subsequent growth of the vegetative s ... | 1977 | 853288 |
| the occurrence of chitin in the cell walls of the rumen organisms neocallimastix frontalis, piromonas communis and sphaeromonas communis. | | 1977 | 864435 |
| sequence of the phosphoenolpyruvate carboxykinase-encoding cdna from the rumen anaerobic fungus neocallimastix frontalis: comparison of the amino acid sequence with animals and yeast. | the nucleotide sequence of the cdna of the phosphoenolpyruvate carboxykinase-encoding gene from the fungus neocallimastix frontalis, was determined. the deduced amino acid sequence (608 residues) and the predicted protein structure were compared to their counterparts in animals and yeast. catalytic regions (substrate-binding site and nucleotide-binding domains) are highly conserved among fungal and animal organisms. the yeast sequence showed no similarity to the fungal sequence. | 1992 | 1339359 |
| effects of glycerol on the growth, adhesion, and cellulolytic activity of rumen cellulolytic bacteria and anaerobic fungi. | the effect of glycerol on the growth, adhesion, and cellulolytic activity of two rumen cellulolytic bacterial species, ruminococcus flavefaciens and fibrobacter succinogenes subsp. succinogenes, and of an anaerobic fungal species, neocallimastix frontalis, was studied. at low concentrations (0.1-1%), glycerol had no effect on the growth, adhesion, and cellulolytic activity of the two bacterial species. however, at a concentration of 5%, it greatly inhibited their growth and cellulolytic activity ... | 1992 | 1368974 |
| distribution of radioactivity of 14c-amino acids added to the medium in cells and metabolites in cultures of rumen fungi. | a mixture of l-(u-14c) amino acids was added to cultures of 11 strains of rumen anaerobic fungi belonging to neocallimastix frontalis, neocallimastix joyonii, sphaeromonas communis and piromonas communis. fungi were grown in a complex medium with glucose for 4 days. the radioactivity was found in cellular protein (27.7-65.3% of the total radioactivity recovered), lactate (16.9-41.8%), volatile fatty acids (7.4-25.7%) and ethanol (4.6-10.5%). a small amount of radioactivity was recovered in lipid ... | 1992 | 1388689 |
| the inhibition of fungal cellulolysis by cell-free preparations from ruminococci. | the degradation of filter paper by the anaerobic fungus neocallimastix frontalis strain re1 was reduced by the addition of cell-free supernates from cultures of ruminococcus albus strain j6 and r. flavefaciens strains 17 and 007. fungal uptake of, and growth on, glucose was not affected. after gel permeation and anion exchange chromatography, inhibitory activity towards fungal cellulolysis was recovered in a fraction from strain 17 that contained at least five negatively charged polypeptide comp ... | 1992 | 1427008 |
| fractionation of cellulases from the ruminal fungus neocallimastix frontalis eb188. | cellulases from the ruminal fungus neocallimastix frontalis eb188 were separated by using hydroxylapatite column chromatography. seven carboxymethylcellulases, six avicelases, and four beta-glucosidases accounted for the majority of the activities. the separation of enzymes was confirmed by using polyacrylamide gel electrophoresis. electrophoretic migration, analysis of hydrolysis products, and substrate specificity measurements suggested that several different cellulases were secreted in n. fro ... | 1991 | 1664199 |
| dna of some anaerobic rumen fungi: g + c content determination. | the nuclear dnas from five species of anaerobic rumen fungi have been isolated and purified by means of two extraction methods (with and without 8 m urea). their g + c contents have been characterized by the thermal denaturation procedure of marmur and doty. as has already been shown in neocallimastix frontalis, the results obtained by the two techniques demonstrated a very low g + c content (less than 20%) and the constant presence of satellite dna. | 1991 | 1769523 |
| chitin content and chitin synthase activity as indicators of the growth of three different anaerobic rumen fungi. | growth of three different anaerobic rumen fungi neocallimastix frontalis, piromonas communis and sphaeromonas communis was assessed in vitro at regular intervals by measurements of protein and chitin content and of chitin synthase activity of the cell free extracts. similar trends and a comparable amount of protein and chitin were observed in the three species. however, chitin synthase activity was higher in s. communis and contrary to the activity of the other two strains did not decrease after ... | 1991 | 1855652 |
| kinetic study of a cellobiase purified from neocallimastix frontalis eb188. | a cellobiase was purified from the culture supernatant of neocallimastix frontalis eb188. this enzyme possessed a molecular weight of 85,000 and an isoelectric point of 6.95. the enzyme rapidly hydrolyzed cellobiose, p-nitrophenyl (pnp) beta-d-glucopyranoside (pnpg) and cellotriose and slowly hydrolyzed cellopentaose and salicin. the enzyme did not hydrolyze pnp alpha-d-glucopyranoside or pnp beta-d-cellobioside. substrate inhibition was observed when cellobiose or pnpg were used as the substrat ... | 1991 | 1932090 |
| purification and characterization of an extracellular beta-xylosidase from the rumen anaerobic fungus neocallimastix frontalis. | the purification of beta-xylosidase (beta-d-xyloside xylohydrolase, ec 3.2.1.37) from neocallimastix frontalis was performed by ammonium sulphate precipitation, ion exchange chromatography, gel filtration and preparative isoelectric focusing. the enzyme had a molecular mass of 180,000 da, an isoelectric point at ph 4.35 and catalysed the hydrolysis of p-nitrophenyl-beta-d-xylopyranoside optimally at ph 6.5 and 35 degrees c with a km of 0.33 mg ml-1. the enzymatic activity was strongly increased ... | 1990 | 2126511 |
| effect of coumarin on glucose uptake by anaerobic rumen fungi in the presence and absence of methanobrevibacter smithii. | the effect of coumarin (1,2 benzopyrone) on glucose utilisation by the anaerobic rumen fungi neocallimastix frontalis and n. patriciarum has been compared with the effect of p-coumaric acid. both compounds largely inhibited glucose utilisation by n. patriciarum strain cx when present in the medium at a concentration of 2.5 mm, and had a similar effect on n. frontalis strain re1 at 5 mm. although in earlier studies co-culturing rumen fungi with methanobrevibacter smithii enhanced resistance to io ... | 1990 | 2227350 |
| supernatant protein and cellulase activities of the anaerobic ruminal fungus neocallimastix frontalis eb188. | protein and cellulose activities were measured in culture supernatants of the anaerobic ruminal fungus neocallimastix frontalis eb188 established in glucose medium and switched to either glucose, cellobiose, or cellulose media. polyacrylamide gel electrophoresis was used to show differences caused by changing medium carbon source. culture supernatants contained proteins with molecular weights ranging from greater than 116,000 to about 19,000. low levels of cellulose activity were evident in gluc ... | 1990 | 2310186 |
| enhanced resistance of anaerobic rumen fungi to the ionophores monensin and lasalocid in the presence of methanogenic bacteria. | the presence of methanobrevibacter smithii altered the susceptibility of the anaerobic fungi neocallimastix frontalis and piromonas communis to the carboxylic ionophores monensin and lasalocid. the ionophores depressed growth (measured by chitin accretion), the uptake of glucose and the production of h2, formate and acetate by the fungi growing axenically in semi-solid medium. in the presence of m. smithii, the sensitivity of the fungi to monensin and lasalocid was decreased. for example, the up ... | 1989 | 2722716 |
| production of xylanase by the ruminal anaerobic fungus neocallimastix frontalis. | xylanase (1,4-beta-d-xylan xylanohydrolase, ec 3.2.1.8) production was investigated in the ruminal anaerobic fungus neocallimastix frontalis. the enzyme was released principally into the culture fluid and had ph and temperature optima of 5.5 and 55 degrees c, respectively. in the presence of low concentrations of substrate, the enzyme was stabilized at 50 degrees c. xylobiose was the principal product of xylanase action, with lesser amounts of longer-chained xylooligosaccharides. no xylose was d ... | 1989 | 2729975 |
| effect of the novel ionophore tetronasin (ici 139603) on ruminal microorganisms. | the antimicrobial activity of the novel ionophore tetronasin (formerly ici 139603) was compared with that of monensin for the growth of ruminal bacteria, protozoa, and an anaerobic fungus. the potency of tetronasin toward most bacteria and the fungus was an order of magnitude or more greater than that of monensin. lactobacillus casei was 55 times more sensitive to tetronasin than to monensin, indicating a potential role for tetronasin in reversing lactic acidosis. bacteria with a gram-positive u ... | 1988 | 3355139 |
| synergism of rumen microbial hydrolases during degradation of plant polymers. | in isolated mixture of exocellular enzymes of rumen bacteria ruminococcus flavefaciens, butyrivibrio fibrisolvens and rumen fungus neocallimastix frontalis, specific activities of cellulases, hemicellulases and glycosidases were determined. the highest specific activities were shown mostly for proteins of n. frontalis. | 1988 | 3397009 |
| [effect of lasalocid on the fermentation of glucose by neocallimastix frontalis rk 21]. | in this study, the effect of the antibiotic lasalocid on the rumen anaerobic fungus neocallimastix frontalis rk 21 was examined. it was thought that lasalocid increased the efficiency of feed utilization by cattle by altering the rumen fermentation. there was a decrease in h2 and acetate production against the increasing concentrations of lasalocid while propionate and butyrate did not appear to be effected. glucose uptake was reduced considerably. | 1987 | 3441225 |
| production and regulation of cellulase by two strains of the rumen anaerobic fungus neocallimastix frontalis. | cellulase production was examined in two strains of neocallimastix frontalis, namely, pn-1 isolated from the ovine rumen, and pn-2 from the bovine rumen. for both strains, carboxymethylcellulase (cmcase) had a ph optimum of 6.0 and a temperature optimum of 50 degrees c. cmcase resided mainly in the culture fluid, and activities up to 170 u ml-1 (1 u represents 1 microgram of glucose equivalents released per min) were obtained for cultures grown on 2.5 mg of cellulose ml-1. for resting cultures o ... | 1985 | 3923931 |
| effects of live saccharomyces cerevisiae cells on zoospore germination, growth, and cellulolytic activity of the rumen anaerobic fungus, neocallimastix frontalis mch3. | the effects of a live yeast strain of saccharomyces cerevisiae have been investigated on zoospore germination, metabolism, and cellulolytic activity of the anaerobic rumen fungus neocallimastix frontalis mch3. the addition of yeast cells to a vitamin-deficient medium stimulated the germination of fungal zoospores, increased cellulose degradation and hydrogen, formate, lactate, and acetate production. responses depended on the concentration of yeast cells added and on their viability. yeast suppl ... | 1995 | 7549764 |
| location by fluorescence microscopy of glycosidases and a xylanase in the anaerobic gut fungi caecomyces communis, neocallimastix frontalis, and piromyces rhizinflata. | beta-d-glucosidase, beta-d-fucosidase, beta-d-xylosidase, and beta-d-cellobiopyranosidase activities in caecomyces communis, neocallimastix frontalis, and piromyces rhizinflata, located with fluorescent conjugates, occur throughout the whole thallus as from zoospore germination and disappear before sporulation. beta-d-galactosidase and alpha-l-arabinopyranosidase activities are low or nonexistent. a xylanase, detected by indirect immunofluorescence, was observed at the surface of the vegetative ... | 1995 | 7549768 |
| alpha-(4-o-methyl)-d-glucuronidase activity produced by the rumen anaerobic fungus piromonas communis: a study of selected properties. | the rumen anaerobic fungus piromonas communis, unlike the rumen anaerobic fungi neocallimastix frontalis and neocallimastix patriciarum, produced extracellular alpha-(4-o-methyl)-d-glucuronidase when grown in cultures containing filter-paper, barley straw, birchwood xylan or birchwood sawdust as carbon source. the highest concentration of enzyme was produced in cultures containing birchwood sawdust. the aldobiouronic acid o-alpha-(4-o-methyl-d-glucopyranosyluronic acid)-(1-->2)-d-xylopyranose (m ... | 1995 | 7576556 |
| effect of anaerobic fungi on glycoside hydrolase and polysaccharide depolymerase activities, in sacco straw degradation and volatile fatty acid concentrations in the rumen of gnotobiotically reared lambs. | four naturally born lambs were placed in sterile isolators 24 h after birth, before the natural establishment of the cellulolytic microorganisms. at the age of 4 weeks, a cellulolytic bacterial population of approximately 10(8) cells g-1 of rumen contents was established by inoculation with a 10(-6) dilution of ruminal contents taken from an adult sheep. a pure culture of neocallimastix frontalis mch3 and piromyces communis fl was inoculated into the rumen 5 months after birth and a stable popul ... | 1995 | 7612171 |
| neocallimastix frontalis enolase gene, enol: first report of an intron in an anaerobic fungus. | a dna clone containing a putative enolase gene was isolated from a genomic dna library of the anaerobic fungus neocallimastix frontalis. it was deduced from sequence comparisons that the enolase gene was interrupted by a large 331 bp intron. the enolase gene, termed enol, has an orf of 1308 bp and encodes a predicted 436 amino acid protein. the deduced amino acid sequence shows high identity (71.5-71%) to those of enolases from the yeasts saccharomyces cerevisiae and candida albicans. the g+c co ... | 1995 | 7670633 |
| effect of condensed tannins from birdsfoot trefoil on endoglucanase activity and the digestion of cellulose filter paper by ruminal fungi. | the ruminal fungi neocallimastix frontalis re1, neocallimastix patriciarum 27, piromyces communis 22, and orpinomyces joyonii 19-2 were examined for their ability to digest filter paper in the presence of condensed tannins from birdsfoot trefoil (lotus corniculatus l.). for all four fungi, inhibition of endoglucanases was evident at 100 micrograms condensed tannins.ml-1 with nearly complete inhibition at 300 micrograms condensed tannins.ml-1. at 100 and 200 micrograms condensed tannins.ml-1, the ... | 1994 | 8039053 |
| effect of eubacterium limosum, a ruminal hydrogenotrophic bacterium, on the degradation and fermentation of cellulose by 3 species of rumen anaerobic fungi. | the degradation and fermentation of cellulose filter paper were studied in axenic cultures of 3 species of rumen anaerobic fungi, neocallimastix frontalis, piromyces communis and caecomyces communis, and in cocultures containing 1 of these fungal strains and eubacterium limosum, a hydrogenotrophic rumen bacterial species. when e limosum was introduced into fungal cultures a slight decrease in fungal cellulolytic activity was observed. the end products of the fermentation of cellulose found in th ... | 1993 | 8142039 |
| purification and characterization of two 1,4-beta-xylan endohydrolases from the rumen fungus neocallimastix frontalis. | two beta-endoxylanases produced by neocallimastix frontalis have been purified by ammonium sulfate precipitation, gel filtration, and ion-exchange chromatography. xylanase i is a nonglycosylated protein with an apparent molecular mass of 45 kda. xylanase ii is a glycoprotein with an apparent molecular mass of 70 kda. the ph optima of these enzymes were 5.5 and 6, respectively, and the temperature optimum was 55 degrees c for each enzyme. the endo mode of action of the enzymes was revealed by thi ... | 1993 | 8285672 |
| inhibition of the cellulolytic activity of neocallimastix frontalis by ruminococcus flavefaciens. | a study was made of the antagonistic effect of ruminococcus flavefaciens on the cellulolytic activity of neocallimastix frontalis. an extracellular factor inhibiting the cellulolytic activity of the fungus was detected in the bacterial supernatant. the antagonistic factor, which precipitated with ammonium sulphate at 40% saturation, was temperature-sensitive and was destroyed at temperatures above 60 degrees c. after separation by anion-exchange chromatography, sequential precipitation, dialysis ... | 1993 | 8515242 |
| characterization of the "promoter region" of the enolase-encoding gene enol from the anaerobic fungus neocallimastix frontalis: sequence and promoter analysis. | the sequence of the neocallimastix frontalis enolase gene promoter was determined up to 1800 nucleotides 5' to the major transcriptional start point. the base composition of the enolase upstream sequence revealed a very a + t-rich profile (13.5% g + c) leading to many putative hairpin structures. the functional organization of the n. frontalis enolase promoter was investigated by heterologous transient-expression assays. dna fragments obtained by the sequential removal of sequences upstream of t ... | 1995 | 8536317 |
| the cellulase system of the anaerobic rumen fungus neocallimastix frontalis: studies on the properties of fractions rich in endo-(1-->4)-beta-d-glucanase activity. | seven fractions rich in endoglucanase activity were separated from the extracellular cellulase system of the anaerobic rumen fungus neocallimastix frontalis. the fractions (es1, es3, es2u1, es2u2, es2u4, es2u3c1 and es2u3c2) were separated from each other and from a fraction that could solubilize crystalline cellulose (the so-called crystalline-cellulose-solubilizing component, ccsc) by the sequential use of differential adsorption on the microcrystalline cellulose avicel, gel filtration and aff ... | 1995 | 8579830 |
| the effect of rumen chitinolytic bacteria on cellulolytic anaerobic fungi. | the polycentric anaerobic fungus orpinomyces joyonii a4 was cultivated on microcrystalline cellulose alone and in association with the rumen chitinolytic bacterium clostridium sp. strain chk5, which shows strong phenotypic similarity to clostridium tertium. the presence of strain chk5 significantly depressed the solubilization of microcrystalline cellulose, the production of short-chain fatty acids (scfa) and the release of endoglucanase by the fungus. co-culture of the monocentric anaerobic fun ... | 1996 | 8862027 |
| molecular characterization of xyn3, a member of the endoxylanase multigene family of the rumen anaerobic fungus neocallimastix frontalis. | different cdnas designated xyn3 and xyn4 were isolated from an expression library of the anaerobic rumen fungus neocallimastix frontalis. xyn3 was further characterized and was shown to contain a single open reading frame of 1821 bp coding for a protein, xyn3, of 607 amino acids (mr 66 000). the predicted primary structure of xyn3 consisted of two large reiterated regions of 223 amino acids with a high degree of identity (88.3%). each domain of xyn3, xyn3a and xyn3b, showed significant homology ... | 1996 | 8939815 |
| scsb, a cdna encoding the hydrogenosomal beta subunit of succinyl-coa synthetase from the anaerobic fungus neocallimastix frontalis. | a clone containing a neocallimastix frontalis cdna assumed to encode the beta subunit of succinyl-coa synthetase (scsb) was identified by sequence homology with prokaryotic and eukaryotic counter-parts. an open reading frame of 1311 bp was found. the deduced 437 amino acid sequence showed a high degree of identity to the beta-succinyl-coa synthetase of escherichia coli (46%), the mitochondrial beta-succinyl-coa synthetase from pig (48%) and the hydrogenosomal beta-succinyl-coa synthetase from tr ... | 1996 | 9003318 |
| hydrogenosomes in the anaerobic fungus neocallimastix frontalis have a double membrane but lack an associated organelle genome. | the presence of hydrogenosomes in phylogenetically distinct anaerobic eukaryotes implies that they have been acquired independently, and previously reported differences in ultrastructure among taxa have suggested that some hydrogenosomes have different origins. of particular interest are reports that neocallimastix frontalis hydrogenosomes resemble microbodies in possessing a single membrane, in contrast to those in ciliates and trichomonads which have two and thus resemble mitochondria. in this ... | 1997 | 9187356 |
| a double membrane surrounds the hydrogenosomes of the anaerobic fungus neocallimastix frontalis. | the structure of hydrogenosomes of the anaerobic fungus neocallimastix frontalis was analyzed using routine preparations for transmission electron microscopy, freeze-fracture and immunocytochemistry. they appeared as round or elongated structures, always enveloped by two distinct, but tightly apposed membranes. images of organelle division were very similar to those observed in trichomonad protozoa. these observations suggest that hydrogenosomes are homologous organelles in unrelated species wea ... | 1997 | 9311125 |
| the hydrogenosomal malic enzyme from the anaerobic fungus neocallimastix frontalis is targeted to mitochondria of the methylotrophic yeast hansenula polymorpha. | hydrogenosomal proteins always contain an amino-terminal extension which is believed to be a hydrogenosomal targeting signal. in the anaerobic fungus neocallimastix frontalis these putative targeting signals are 27 amino acids long, are enriched in ala, leu, ser and arg, and have an arg at position -2 relative to amino-acid 1 of the mature protein. these features are typically observed in mitochondrial targeting signals. here we show that the 27 amino-acid leader sequence of the hydrogenosomal m ... | 1998 | 9506901 |
| multiplicity and expression of xylanases in the rumen fungus neocallimastix frontalis. | the time course production of xylanolytic enzymes by the rumen anaerobic fungus neocallimastix frontalis was studied during growth on different carbon sources and revealed using isoelectric focusing and immunoblotting. a constant low level of endoxylanase expression was observed in glucose medium. a high level of xylanase activity was detected in methyl glucoside medium corresponding to the induction of new isoforms which were repressed by the presence of glucose. beta-xylosidases were constitut ... | 1998 | 9675850 |
| cloning, sequencing, and expression of an endoglucanase gene from the rumen anaerobic fungus neocallimastix frontalis mch3. | a cdna clone encoding an endo-1,4-beta-glucanase from a rumen fungus, neocallimastix frontalis mch3, was isolated. the nucleotide sequence showed that the gene, cela, encoded a multidomain enzyme containing a family 5 catalytic domain and a reiterated sequence that is involved in the association of a multienzyme complex, the cellulosome. the enzyme expressed in escherichia coli showed the highest activity against carboxymethylcellulose at 40 degrees c and ph 8.5. | 1998 | 9805384 |
| fermentation extract effects on the morphology and metabolism of the rumen fungus neocallimastix frontalis eb188. | the effects of aspergillus oryzae fermentation extract, amaferm, on the rumen fungus neocallimastix frontalis eb188 were studied. the secretion of cellulase was increased by 67% and rhyzoid development was increased 3.8-fold in the presence of extract. strength of fungal response increased in a dose-dependent manner and demonstrated a positive correlation between cell surface area and enzyme secretion. above certain concentrations of extract, however, the development of the fungus and enzyme sec ... | 1999 | 10196744 |
| expression of a catalytic domain of a neocallimastix frontalis endoxylanase gene (xyn3) in kluyveromyces lactis and penicillium roqueforti. | a cdna fragment encoding the a catalytic domain of the neocallimastix frontalis endoxylanase xyn3 was amplified and cloned by the polymerase chain reaction technique. the xyn3a dna fragment was inserted between the saccharomyces cerevisiae phosphoglycerate kinase gene promoter and terminator sequences on a multicopy episomal plasmid for kluyveromyces lactis. the xyn3a domain was successfully expressed in k. lactis and functional endoxylanase was secreted by the yeast cells with the k. lactis kil ... | 1999 | 10499260 |
| effect of steroidal saponin from yucca schidigera extract on ruminal microbes. | the effects of steroidal saponins (sap) isolated from yucca schidigera extract on ruminal bacteria and fungi were investigated in pure culture studies. prevotella bryantii, ruminobacter amylophilus, selenomonas ruminantium and streptococcus bovis were cultured through ten 24-h transfers in ruminal fluid medium containing 0 or 25 microg sap ml-1 (measured as smilagenin equivalents). the four strains, each non-exposed or pre-exposed to sap, were then inoculated into medium containing 0 or 250 micr ... | 2000 | 10792550 |
| degradation of fresh ryegrass by methanogenic co-cultures of ruminal fungi grown in the presence or absence of fibrobacter succinogenes. | the ability of five ruminal fungi in syntrophic co-culture with the methanogen methanobrevibacter smithii to degrade perennial ryegrass ( lolium perenne) stem fragments and leaf blades was studied to determine the susceptibilities of non-autoclaved fresh tissues to fungal degradation. autoclaving did not significantly increase fungal degradation of stem fragments but strongly increased degradation of leaf blades by a species of caecomyces. in methanogenic co-cultures, non-autoclaved stem fragmen ... | 2002 | 12029527 |
| catalytic properties of endoxylanase fusion proteins from neocallimastix frontalis and effect of immobilization onto metal-chelate matrix. | the production of hybrid enzymes with novel properties and the research for new methods for enzyme immobilization in bioreactors are of major interest in biotechnology. we report here the second part of a study concerning the improvement of the properties of the endoxylanase xyn3a4 from the anaerobic fungi neocallimastix frontalis. the effects of gene fusion and immobilization on metal-chelate matrix are also compared for the reference enzymes xyn3, xyn3a, xyn4 used for the construction of the f ... | 2003 | 12615394 |
| characterization of aspergillus oryzae fermentation extract effects on the rumen fungus neocallimastix frontalis, eb 188. part 1. zoospore development and physiology. | experiments were performed to determine the effect of aspergillus oryzae (ao) fermentation extract on zoospore development in the rumen fungus neocallimastix frontalis eb 188. powdered product, or liquid extract prepared from such powder, was added at the recommended value for supplementation in dairy cattle. stationary and stirred cultures were periodically sampled and assayed for extracellular and intracellular protein and enzymes, gas production, zoospore production and maturation, and carbon ... | 2004 | 12690417 |
| characterization of aspergillus oryzae fermentation extract effects on the rumen fungus neocallimastix frontalis, eb 188. part 2. carbon source utilization and effects on zoospore production. | the effect of a commercial aspergillus oryzae fermentation extract on the utilization of carbon source and zoospore production by the rumen fungus neocallimastix frontalis eb 188 was determined. in addition, the composition of a soluble extract prepared from the commercial product was analyzed. this extract was added to n. frontalis eb 188 cultures grown on a variety of substrates and periodically assayed for protein, enzymes, zoospore production, and carbon source utilization. the powdered prod ... | 2004 | 12690418 |
| pyruvate formate lyase (pfl) and pfl activating enzyme in the chytrid fungus neocallimastix frontalis: a free-radical enzyme system conserved across divergent eukaryotic lineages. | fermentative formate production involves the activity of pyruvate formate lyase, an oxygen-sensitive enzyme that employs a glycyl radical in its reaction mechanism. while common among anaerobic prokaryotes, this enzyme has so far been found in only two distantly related eukaryotic lineages, anaerobic chytridiomycetes and chlorophytes. sequence comparisons of homologues from the chytridiomycetes piromyces and neocallimastix, the chlorophyte chlamydomonas, and numerous prokaryotes suggest a single ... | 2004 | 15352329 |
| effects of dockerin domains on neocallimastix frontalis xylanases. | two xylanase genes were cloned from the anaerobic fungus neocallimastix frontalis. xyn11a had a modular structure of two catalytic domains and two dockerin domains, while xyn11b had one catalytic domain and two dockerin domains. the characteristics of the xylanases with and without dockerin domains were investigated. the deletion of dockerin domains had little influence on the optimal ph of xylanases, while it significantly affected the optimal temperatures. the optimal temperatures increased fr ... | 2005 | 15686849 |
| palladium-mediated hydrogenation of unsaturated hydrocarbons with hydrogen gas released during anaerobic cellulose degradation. | among five hydrogenation catalysts, palladium on charcoal was the most reactive one when suspended in anaerobic culture medium, and lindlar catalyst (pd on caco(3)) was the most reactive one when suspended in the gas phase of culture tubes. palladium on charcoal in the culture medium (40 to 200 mg 10 ml) completely inhibited growth of neocallimastix frontalis and partly inhibited ruminococcus albus. lindlar catalyst (40 to 200 mg per tube) suspended in a glass pouch above the culture medium did ... | 1986 | 16347167 |
| effect of methanobrevibacter smithii on xylanolytic activity of anaerobic ruminal fungi. | three different ruminal anaerobic fungi, neocallimastix frontalis pnk2, sphaeromonas communis b7, and piromonas communis b19, were grown axenically or in coculture with methanobrevibacter smithii on xylan. n. frontalis and s. communis in monoculture and coculture accumulated xylobiose, xylose, and arabinose in the growth medium; arabinose was not metabolized, but xylobiose and xylose were subsequently used. the transient accumulation of xylose was much less evident in cocultures. both the rate a ... | 1990 | 16348244 |
| transformation of (sup14)c-lignin-labeled cell walls of wheat by syntrophococcus sucromutans, eubacterium oxidoreducens, and neocallimastix frontalis. | wheat cell walls, saponified or not, labeled with [u-(sup14)c]phenylalanine or [o-methyl-(sup14)c]sinapate were fermented by neocallimastix frontalis or syntrophococcus sucromutans plus eubacterium oxidoreducens or a mixed culture. phenolics were less solubilized but more transformed by bacteria than by the fungus, and mineralization was slight. s. sucromutans o-demethylated [o-methyl-(sup14)c]syringyl lignins, yielding labeled acetate. | 1995 | 16534916 |
| metabolism of polyunsaturated fatty acids and their toxicity to the microflora of the rumen. | ruminal microorganisms hydrogenate polyunsaturated fatty acids (pufa) present in forages and thereby restrict the availability of health-promoting pufa in meat and milk. the aim of this study was to investigate pufa metabolism and the influence of pufa on members of the ruminal microflora. eleven of 26 predominant species of ruminal bacteria metabolised linoleic acid (la; cis-9,cis-12-18:2) substantially. the most common product was vaccenic acid (trans-11-18:1), produced by species related to b ... | 2007 | 17072533 |
| mitochondrial steps of arginine biosynthesis are conserved in the hydrogenosomes of the chytridiomycete neocallimastix frontalis. | arginine biosynthesis in eukaryotes is divided between the mitochondria and the cytosol. the anaerobic chytridiomycete neocallimastix frontalis contains highly reduced, anaerobic modifications of mitochondria, the hydrogenosomes. hydrogenosomes also occur in the microaerophilic flagellate trichomonas vaginalis, which does not produce arginine but uses one of the mitochondrial enzymes, ornithine transcarbamoylase, in a cytosolic arginine dihydrolase pathway for atp generation. est sequencing and ... | 2007 | 17300518 |
| effects of phenolic monomers on the enzymes activities and volatile fatty acids production of neocallimastix frontalis b9. | the effects of phenolic monomers (i.e. rho-coumaric acid, ferulic acid, rho-hydroxybenzaldehyde and vanillin) on the enzymes and fermentation activities of neocallimastix frontalis b9 grown in ball-milled filter paper and guinea grass media were studied. the enzymes studied were carboxymethylcellulase (cmcase), filterpaperase (fpase), xylanase and beta-glucosidase. at 96 h of incubation, n. frontalis grown in ball-milled filter paper medium produced comparable xylanase and cmcase activities (0.4 ... | 2008 | 18083606 |
| degradation of lignified secondary cell walls of lucerne (medicago sativa l.) by rumen fungi growing in methanogenic co-culture. | to compare the abilities of the monocentric rumen fungi neocallimastix frontalis, piromyces communis and caecomyces communis, growing in coculture with methanobrevibacter smithii, to colonize and degrade lignified secondary cell walls of lucerne (alfalfa) hay. | 2011 | 21848807 |
| hydrolysis of xylo-oligosaccharides by a beta-xylosidase from the rumen anaerobic fungus neocallimastix frontalis. | | 2006 | 1426560 |
| glycosidases of the rumen anaerobic fungus neocallimastix frontalis grown on cellulosic substrates. | the rumen anaerobic fungus neocallimastix frontalis was grown on cellulosic substrates, and the cellular distribution and types of glycosidases produced by the organism were studied. fungal cultures were fractionated into extracellular, insoluble (membrane), and intracellular fractions and assayed for glycosidase activity by using avicel, carboxymethylcellulose, xylan, starch, polygalacturonic acid, and the p-nitrophenyl derivatives of galactose, glucose, and xylose as substrates. enzymic activi ... | 2014 | 4004240 |
| finding a robust strain for biomethanation: anaerobic fungi (neocallimastigomycota) from the alpine ibex (capra ibex) and their associated methanogens. | anaerobic fungi occupy the rumen and digestive tract of herbivores, where they play an important role in enzymatic digestion of lignocellulosic and cellulosic substrates, i.e. organic material that their hosts are unable to decompose on their own. in this study we isolated anaerobic fungi from a typical alpine herbivore, the alpine ibex (c. ibex). three fungal strains, either as pure culture (st2) or syntrophic co-culture with methanogens (st3, st4) were successfully obtained and morphologically ... | 2014 | 24384307 |
| characterization of heterologously expressed acetyl xylan esterase1 isolated from the anaerobic rumen fungus neocallimastix frontalis pma02. | acetyl xylan esterase (axe), which hydrolyzes the ester linkages of the naturally acetylated xylan and thus known to have an important role for hemicellulose degradation, was isolated from the anaerobic rumen fungus neocallimastix frontatlis pma02, heterologously expressed in escherichi coli (e.coli) and characterized. the full-length cdna encoding nfaxe1 was 1,494 bp, of which 978 bp constituted an open reading frame. the estimated molecular weight of nfaxe1 was 36.5 kda with 326 amino acid res ... | 2016 | 27383808 |
| phylogeny of anaerobic fungi (phylum neocallimastigomycota), with contributions from yak in china. | the phylum neocallimastigomycota contains eight genera (about 20 species) of strictly anaerobic fungi. the evolutionary relationships of these genera are uncertain due to insufficient sequence data to infer their phylogenies. based on morphology and molecular phylogeny, thirteen isolates obtained from yak faeces and rumen digesta in china were assigned to neocallimastix frontalis (nine isolates), orpinomyces joyonii (two isolates) and caecomyces sp. (two isolates), respectively. the phylogenetic ... | 2017 | 27734254 |
| fiber degradation potential of natural co-cultures of neocallimastix frontalis and methanobrevibacter ruminantium isolated from yaks (bos grunniens) grazing on the qinghai tibetan plateau. | several natural anaerobic fungus-methanogen co-cultures have been isolated from rumen and feces source of herbivores with strong fiber degrading ability. in this study, we isolated 7 neocallimastix with methanogen co-cultures from the rumen of yaks grazing on the qinghai tibetan plateau. based on morphological characteristics and internal transcribed spacer 1 sequences (its1), all the fungi were identified as neocallimastix frontalis. the co-cultures were confirmed as the one fungus - one methan ... | 2016 | 26979345 |
| isolation, identification and fibrolytic characteristics of rumen fungi grown with indigenous methanogen from yaks (bos grunniens) grazing on the qinghai-tibetan plateau. | to obtain co-cultures of anaerobic fungi and their indigenously associated methanogens from the rumen of yaks grazing on the qinghai-tibetan plateau and investigate their morphology features and ability to degrade lignocellulose. | 2016 | 26910857 |
| effects of aromatic amino acids, phenylacetate and phenylpropionate on fermentation of xylan by the rumen anaerobic fungi, neocallimastix frontalis and piromyces communis. | anaerobic fungi are important members of the fibrolytic community of the rumen. the aim of this study was to study their requirement for aromatic amino acids (aa) and related phenyl acids (phenylpropionic and phenylacetic acids) for optimal xylan fermentation. | 2007 | 17897195 |
| efficient production of cellulolytic and xylanolytic enzymes by the rumen anaerobic fungus, neocallimastix frontalis, in a repeated batch culture. | in a batch culture of neocallimastix frontalis in a medium (ph 6.8) containing 8 g.l(-1) cellulose, the concentrations of the fermentation products and the cellulolytic and xylanolytic enzymes did not increase in comparison with those of cultures in a medium containing 4 g.l(-1) cellulose. therefore, kinetic studies were performed to determine the effect that products such as acetate, formate, lactate and ethanol have in inhibiting the growth. the reduction of the specific growth rate by the fer ... | 2001 | 16232967 |
| the genetic similarity of different generations of neocallimastix frontalis sk. | the genetic similarity of different generations of neocallimastix frontalis sk was examined by random amplified polymorphic dna (rapd) profiling and internal transcribed spacer 1 (its1) sequence analysis. n. frontalis sk was subcultured every 2-4 days, and sk-1, sk-3m, and sk-1y represented n. frontalis sk cultures after one subculture, 50 subcultures, and 150 subcultures. the dna polymorphisms of the different n. frontalis sk generations were compared by rapd profiling. the rapd results gave th ... | 2003 | 12725931 |
| an [fe] hydrogenase from the anaerobic hydrogenosome-containing fungus neocallimastix frontalis l2. | hydrogenases, oxygen-sensitive enzymes that can make hydrogen gas, are key to the function of hydrogen-producing organelles (hydrogenosomes), which occur in anaerobic eukaryotes scattered throughout the eukaryotic tree. all of the eukaryotic enzymes characterized so far are iron-only [fe] hydrogenases. in contrast, it has previously been suggested that hydrogenosomes of the best-studied anaerobic fungus neocallimastix frontalis l2 contain an unrelated iron-nickel-selenium [nifese] hydrogenase. w ... | 2002 | 12383502 |
| de novo synthesis of amino acids by the ruminal anaerobic fungi, piromyces communis and neocallimastix frontalis. | anaerobic fungi are an important component of the cellulolytic ruminal microflora. ammonia alone as n source supports growth, but amino acid mixtures are stimulatory. in order to evaluate the extent of de novo synthesis of individual amino acids in piromyces communis and neocallimastix frontalis, isotope enrichment in amino acids was determined during growth on (15)nh(4)cl in different media. most cell n (0.78 and 0.63 for p. communis and n. frontalis, respectively) and amino acid n (0.73 and 0. ... | 2002 | 12113941 |
| isolation and analysis of two cellulase cdnas from orpinomyces joyonii. | two cellulase cdnas, celb29 and celb2, were isolated from a cdna library derived from mrna extracted from the anaerobic fungus, orpinomyces joyonii strain sg4. the nucleotide sequences of celb2 and celb29 and the primary structures of the proteins encoded by these cdnas were determined. the larger celb29 cdna was 1966bp long and encoded a 477 amino acid polypeptide with a molecular weight of 54kda. analysis of the 1451bp celb2 cdna revealed an 1164bp open reading frame coding for a 44kda protein ... | 2000 | 10713452 |
| transient expression of the beta-glucuronidase gene after biolistic transformation of the anaerobic fungus neocallimastix frontalis. | the rumen anaerobic fungus neocallimastix frontalis was biolistically transformed using plasmids containing the bacterial beta-glucuronidase gene (gus) fused to the promoter sequences of the enolase gene from n. frontalis. multiple copies of the plasmids were precipitated onto tungsten particles and delivered into zoosporangia and a mycelial mat by a helium-driven biolistic device. transformants were detected by histochemical assay for beta-glucuronidase. it was found that the enolase promoter s ... | 1997 | 9021133 |
| a mitochondrial-like targeting signal on the hydrogenosomal malic enzyme from the anaerobic fungus neocallimastix frontalis: support for the hypothesis that hydrogenosomes are modified mitochondria. | the hydrogenosomal malic enzyme (me) was purified from the anaerobic fungus neocallimastix frontalis. using reverse genetics, the corresponding cdna was isolated and characterized. the deduced amino acid sequence of the me showed high similarity to me from metazoa, plants and protists. putative functional domains for malate and nad+/nadp+ binding were identified. phylogenetic analysis of the deduced amino acid sequence of the new me suggests that it is homologous to reference bacterial and eukar ... | 1997 | 9004216 |
| effects of coumarin and sparteine on attachment to cellulose and cellulolysis by neocallimastix frontalis re1. | the plant secondary metabolites coumarin and sparteine reduced attachment to cellulose, cellulose solubilization, and the proportion of lactate in the fermentation products of the anaerobic fungus neocallimastix frontalis re1. neither compound directly inhibited the endoglucanase or lactate dehydrogenase activities of cell extracts of the fungus. | 1996 | 16535476 |
| hydrolysis of oligosaccharides of the β-(1→4)-linked d-xylose series by an endo(1→4)-β-d-xylanase from the anaerobic rumen fungus neocallimastix frontalis. | an endo-(1→4)-β-d-xylanase from neocallimastix frontalis was purified by anion-exchange chromatography. the enzyme had an apparent molecular mass of 30 kda on sds-page and exhibited maximum activity at 50°c and at ph values between 6.0 and 6.6. kinetic studies on the hydrolysis of xylo-oligosaccharides, ranging from xylobiose to xylodecaose, showed that xylohexaose and xyloheptaose were the preferred substrates for the enzyme and that xylobiose, xylotriose and xylotetraose were not hydrolysed. x ... | 1994 | 24420889 |
| purification and characterisation of a beta-d-xylosidase from the anaerobic rumen fungus neocallimastix frontalis. | a beta-d-xylosidase from the anaerobic rumen fungus neocallimastix frontalis was purified by anion-exchange and gel filtration chromatography. the enzyme was isoelectrically homogeneous and had an isoelectric point of ph 4.6. the apparent molecular mass calculated by gel filtration was 150,000 da. under denaturing conditions, the enzyme appeared as a dimer composed of two polypeptides with molecular masses of 83,000 and 53,000 da. the ph and temperature optimum were 6.4 and 37 degrees c, respect ... | 1993 | 8495441 |
| anaerobic fungi and their cellulolytic and xylanolytic enzymes. | anaerobic fungi are the inhabitants of the digestive tract of herbivorous mammals, ruminants as well as non-ruminants. one of the major characteristics of all anaerobic fungi examined thus far, is their production and secretion of a range of polysaccharide-degrading enzymes, including cellulases, xylanases and glucoside-hydrolases. the cellulolytic enzymes of the anaerobic fungus neocallimastix frontalis have been shown to possess a high activity. therefore anaerobic fungi and/or their enzymes c ... | 1993 | 8480994 |
| glucose metabolic pathways in the anaerobic rumen fungus neocallimastix frontalis eb188. | primary pathways for glucose metabolism were established in the anaerobic rumen fungus neocallimastix frontalis eb188. this highly capable cellulolytic organism demonstrated a strict anaerobic integration of metabolic pathways. glycolysis in n. frontalis eb188 was coupled to malate dehydrogenase, 'malic' enzyme and specified hydrogenosome reactions. pyruvate, as in most life forms, was a pivotal compound. the major fermentation products of n. frontalis eb188 were acetate, ethanol and lactate, wi ... | 1991 | 2006921 |
| molecular cloning of genes from the rumen anaerobic fungus neocallimastix frontalis: expression during hydrolase induction. | glycoside and polysaccharide hydrolase production by the rumen anaerobic fungus, neocalimastix frontalis is induced by the presence of crystalline cellulose. a differential screening of a cdna library was used to isolate dna sequences transcribed at high levels under growth conditions which induce enzyme production. seven clones were isolated that preferentially hybridized to the induced cdna probe versus the non-induced cdna probe. southern analysis showed that a cdna clone (118) hybridized to ... | 1991 | 2004691 |
| purification and characterization of an aspecific glycoside hydrolase from the anaerobic ruminal fungus neocallimastix frontalis. | a glycoside hydrolase characterized by beta-fucosidase (ec 3.2.1.38) and beta-glucosidase (ec 3.2.1.21) activities was purified from the culture medium of the anaerobic ruminal phycomycete neocallimastix frontalis grown on 0.5% avicel. the enzyme had a molecular mass of 120 kilodaltons and a pi of 3.85. optimal activity against p-nitrophenyl-beta-d-fucoside and p-nitrophenyl-beta-d-glucoside occurred at ph 6.0 and 50 degrees c. the beta-fucosidase and beta-glucosidase activities were stable from ... | 1990 | 16348324 |
| production of alpha-amylase by the ruminal anaerobic fungus neocallimastix frontalis. | alpha-amylase production was examined in the ruminal anaerobic fungus neocallimastix frontalis. the enzyme was released mainly into the culture fluid and had temperature and ph optima of 55 degrees c and 5.5, respectively, and the apparent k(m) for starch was 0.8 mg ml. the products of alpha-amylase action were mainly maltotriose, maltotetraose, and longer-chain oligosaccharides. no activity of the enzyme was observed towards these compounds or pullulan, but activity on amylose was similar to st ... | 1988 | 16347742 |
| role of catabolite regulatory mechanisms in control of carbohydrate utilization by the rumen anaerobic fungus neocallimastix frontalis. | neocallimastix frontalis pn-1 utilized the soluble sugars d-glucose, d-cellobiose, d-fructose, maltose, sucrose, and d-xylose for growth. l-arabinose, d-galactose, d-mannose, and d-xylitol did not support growth of the fungus. paired substrate test systems were used to determine whether any two sugars were utilized simultaneously or sequentially. of the paired monosaccharides tested, glucose was found to be preferentially utilized compared with fructose and xylose. the disaccharides cellobiose a ... | 1983 | 6660873 |
| ultrastructural studies of the free zoospore of the rumen phycomycete neocallimastix frontalis. | the structure of the free zoospores of neocallimastix frontalis has been examined by electron microscopy of thin-sectioned and negatively stained preparations. there are up to 15 flagella arranged in two rows. the free end of each flagellum is narrow and its tip does not contain microtubules. the flagella and the cell body are coated with distinct surface layers composed of regular arrays of particles and fibrils, respectively. the cell body contains a variety of inclusions. near to the flagella ... | 1981 | 7198679 |