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Potential use of cutinase in enzymatic scouring of cotton fiber cuticle.

The present study characterized the ability of a bacterial cutinase to improve the wettability of raw cotton fabrics by specific hydrolysis of the cutin structure of the cuticle. The effect of cutinase was studied alone and in coreaction with pectin lyase. The changes in both the fabric and the reaction fluid were measured and compared to enzymatic hydrolysis with polygalacturonase, and to chemical hydrolysis with boiling NaOH. Water absorbancy, specific staining, fabric weight loss, and evaporative light-scattering reverse-phase high-performance liquid chromatography analysis of chloroform extract of the reaction fluid were measured to assess the enzymatic hydrolysis of the cuticle waxy layer. The pattern and extent of hydrolysis of the major cuticle constituents depended on the enzyme type and titers employed and paralleled the degree of wettability obtained. The combination of cutinase and pectin lyase resulted in a synergistic effect. The use of detergents improved enzymatic scouring. The major products released to the reaction medium by the cutinase treatment were identified by gas chromatography/mass spectrometry analysis as C:16 and C:18 saturated fatty acid chains.

Aspergillus niger↗

Differences in the initial events of infection of Botrytis cinerea strains isolated from tomato and grape.

Various stages of the infection process among B. cinerea strains isolated from tomatoes or grapes, belonging to different genetic groups, were compared. It was found that strains of B. cinerea isolated from either grapes or tomatoes showed differences in adhesion patterns and in the percentage of germination on tomato cutin. In strains isolated from tomato the first stage of adhesion occurred faster than in strains isolated from grape. At the same time strains isolated from tomato showed a higher percentage of germination on tomato cutin than the other strains after 9 h of incubation. The production and isoenzymatic patterns of polygalacturonases, pectin methyl esterases, pectin lyases, p-nitrophenylbutyrate esterases and laccases by B. cinerea in solid-state fermentation also were analyzed. Correlation between the production of these enzymes and the origin of the strains was not found. On the other hand all strains produced different isoenzymes and a common pattern between the strains was not observed. The ability of B. cinerea strains to colonize tomato leaves also differs between the isolated strains obtained from grapes and tomato. Strains isolated from tomato were more virulent on tomato leaves than strains isolated from grapes.

Botrytis↗

Comparative study of intracellular and extracellular pectinases produced by Penicillium frequentans.

The filamentous fungus Penicillium frequentans synthesized eleven polygalacturonases (PGs) and two pectinesterases (PEs) when grown in liquid culture supplemented with pectin. Seven PGs and the two PEs were secreted in the medium, whereas four PGs were not secreted. Among the secreted PGs, the endo-PG (band 10) and exo-PGs (band 5) were the enzymes secreted at the highest levels. All secreted PGs bound to lectin and their secretion and/or enzymic activities were inhibited by tunicamycin (TM), except for the constitutive and inducible endo-PG (band 10). Studies on the affinity for concanavalin A (ConA) and the effect of TM suggested that the secreted endo-PG and exo-PG differed in level and process of glycosylation. The exo-PG was characterized as a N-glycoprotein, whereas the endo-PG is probably an O-glycoprotein. The PGs (bands 3 and 4) were neither bound to ConA nor secreted and their enzymic activities were inhibited by TM, suggesting that they are probably N-glycoproteins with complex oligosaccharides of type three and tetra-antennary structure. The other PGs (bands 6 and 8) that were not secreted and did not bind to ConA were not inhibited by TM. These enzymes presented chromatographic characteristics and effects with TM that were similar to endo-PG (band 10), because these PGs might be unglycosylated or/and aggregate forms of the endo-PG (band 10).

Carbohydrates↗

The effects of treatment with enzymatic preparations and tannin phenolic absorbent agents in extracting the olive oil by single pressure process on the oil yield, on the analytical characteristics of the oils of the vegetation waters and of the waste waters.

The vegetation waters of the must, the oils and the waste waters extracted from olive pastes, treated by enzymatic preparations (Cellulase, Hemicellulase, Polygalacturonase and Protease) and tannin phenolic adsorbent agents (Polyclar AT, Methylcellulose, Albumine) employed during crushing of olive were analysed:--the vegetation waters in order to justify some technological results (oil yields and extraction speed) obtained by the treatments;--the oils in order to examine the effects of the treatments on the same chemical characteristics and the stability to rancidity. --The waste waters to verify the possible influence of the treatments on the BOD. From the results relative to the vegetation waters, it has been suggested that the increase of the "detached oil" does occur by two different biochemical mechanisms which involve the constitutive lipoprotein of the oil drop membrane and colloidal constituents of the liquid and solid phase of the pastes. For what concerns the oils, the treatments induce the slight modification of the fatty acid composition and chromatic characteristics, a higher stability to rancidity, a qualitative and quantitative increase of the "headspace" violates constituents above oils. The waste waters obtained from the olive pastes show lower BOD5 values.

Adsorption↗

Studies of pectic enzymes produced by Talaromyces flavus in submerged and solid substrate cultures.

Tons of peel and rag are generated each year by industries of citrus fruit juices. These by-products are used either for the elaboration of pectin or as substrate for enzyme production. Talaromyces flavus produces extracellular pectinesterase and polygalacturonase after 24 h in submerged culture supplemented with 0.5-0.8% citrus pectin preceded by preculture for 24 h in 2% (w/v) sucrose or in solid substrate culture on passion fruit peel, lemon or orange pulp pellets after 3-6 days of incubation. Chromatographic profiles in a CM-Sepharose column of liquid and solid cultures were very similar, consisting of one endopoligalacturonase (endo-PG I) and one pectinolytic complex constituted by an endopoligalacturonase (endo-PG II) and pectinesterase. Pectin and pectate lyases were undetectable in both media. In Talaromyces flavus the synthesis of pectinases was repressed by glucose and finally controlled by the concentration of products from pectic enzymes degradation.

Ascomycota↗

[Production of pectinases by Penicillium simplicissimum A3263 in an amaranth-seed flour medium].

The present work studies the production of pectinases using a strain of Penicillium simplicissimum A3263 and considering the influence of adding Amaranthus cruentus seed meal in a selected medium. We also considered the influence of aeration on enzyme production. Research was oriented towards the production of pectin lyase, the enzyme having the highest commercial value. This work was carried out in Erlenmeyer flasks in rotary shaker to select the medium and in a mechanically stirred fermentor to study aeration. The microorganism was developed as pellets of 1 mm diameter. Enzyme levels were of the order of 8216.21 pectin lyase units and 167.57 polygalacturonase units per gram of fungal biomass, respectively, using a medium containing 40 g/l of amaranth seed meal. As for the influence of aeration, it was determined that the higher values were obtained at 750 rpm corresponding to an oxygen absorption rate of 2691 ml O2/lh for an air flow of 1 l/l.min. The results obtained are considered very important in view of the fact that they exceeded in 550% those obtained by other authors.

Aerobiosis↗

Endopolygalacturonase, an extracellular pectic enzyme of Rhizoctonia fragariae.

A pectolytic enzyme from culture filtrates of Rhizoctonia fragariae was purified approx. 29-fold. The enzyme exhibited maximal depolymerizing activity on Na-polypectate rather than pectin at pH 5.0 and was inhibited at different extent by divalent cations Mg++, Mn++, Ca++. The analysis by paper chromatography of the products of enzyme hydrolysis suggested that the enzyme attacks the substrate by a random mechanism. The absorption spectrum of the chromogen formed by the hydrolysis products and thiobarbituric acid suggested that the enzyme is a hydrolytic enzyme. On the basis of these results the enzyme is classifiable as endo-polygalacturonase (poly alpha-1,4-galacturonide glycanohydrolase E.C. 3.2.1.15).

Calcium↗

[Immobilization of pectawamorine G10x by gel entrapment].

Polyacrylamide gel immobilization of pectawamorine G10x was investigated. Its pectinesterase and polygalacturonase activity and stability in storage were measured. The degree of pectawamorine binding during gel immobilization was 80--90%, 55% of initial activity being retained. Thermal stability of the immobilized and native preparations was equal. Pectinesterase activity of the gel immobilized enzyme increased during storage.

Chromatography, Gel↗

Hydrolytic ability of acid protease of Fusarium culmorum and its possible role in phytopathogenesis.

It was found that the acid protease of Fusarium culmorum can hydrolyze various proteins of plant origin including polygalacturonase inhibitor from bean (BPI) and soybean trypsin inhibitor (STI). The highest hydrolysis extent of BPI and STI by the enzyme was only 5% and 3% respectively. The partially hydrolyzed BPI lost its inhibition ability to fungal polyglacturonases. Similarly, the partially hydrolyzed STI lost its inhibition ability to trypsin and fungal alkaline protease. The F. culmorum acid protease showed broad substrate specificity towards synthetic dipeptides.

Amino Acid Sequence↗

Preliminary study of the pectolytic activity of Cryptococcus albidus var. albidus.

A preliminary study was done on the pectolytic activity of Cryptococcus albidus var. albidus. Cell-free culture broths of six strains of this yeast species were shown to degrade pectin hydrolytically by means of a polygalacturonase-pectinmethylesterase system. Neither pectin nor pectate lyase activities were detected.

Carboxylic Ester Hydrolases↗

Release of ferulic acid from sugar-beet pulp by using arabinanase, arabinofuranosidase and an esterase from Aspergillus niger.

Aspergillus niger cinnamoyl esterase (CinnAE) is shown to be active towards a wide range of feruloylated oligosaccharides derived from sugar-beet pulp (SBP). The esterase hydrolysed ferulic acid ester-linked to either C-2 of arabinose or C-6 of galactose residues, and demonstrated the highest activity towards the feruloylated arabinose trisaccharide. However, CinnAE was able to release only 0.88% of total alkali-extractable ferulic acid from SBP in 24 h when acting alone. To determine whether cell-wall-degrading enzymes could increase the release of ferulic acid by CinnAE, SBP was incubated with various carbohydrases [cellulase, polygalacturonase, endo-arabinanase, alpha-L-arabinofuranosidase, endo-(1,4-beta-D-galactanase, beta-D-galactosidase]. These were added alone and in pairs, both in the presence and absence of CinnAE. We showed that all the carbohydrases tested were free of esterase activity. When individual carbohydrases were incubated with SBP, whether in the presence or absence of CinnAE, less than 1% of the feruloyl groups were released. When incubated with a mixture of endo-arabinanase and alpha-L-arabinofuranosidase, the esterase was able to release 14 times more of the alkali-extractable ferulic acid present in the whole pulp as free acid than CinnAE alone. Ferulic acid is linked either to L-arabinose or D-galactose in SBP, but no corresponding increase in ferulic acid release was detected when SBP was incubated with CinnAE plus endo-(1,4)-beta-D-galactanase and beta-D-galactosidase (both from A. niger). Hence feruloylated arabinans in SBP are readily available for hydrolysis by arabinan-degrading enzymes, whereas feruloylated galactans are not available for hydrolysis by galactan-degrading enzymes.

Aspergillus niger↗

Site-selected insertional mutagenesis of tomato with maize Ac and Ds elements.

Site-selected insertion (SSI) is a PCR-based technique which uses primers located within the transposon and a target gene for detection of transposon insertions into cloned genes. We screened tomato plants bearing single or multiple copies of maize Ac or Ds transposable elements for somatic insertions at one close-range target and two long-range targets. Eight close-range Ds insertions near the right border of the T-DNA were recovered. Sequence analysis showed a precise junction between the transposon and the target for all insertions. Two insertions in separate plants occurred at the same site, but others appeared dispersed in the region of the right T-DNA border with no target specificity. However, insertions showed a preference for one orientation of the transposon. Use of plants with multiple Ac (HiAc) or Ds (HiDs) elements allowed detection of somatic insertions at two single-copy genes, PG (polygalacturonase) and DFR (dihydroflavonol 4-reductase). Certain HiDs plants showed much higher rates of insertion into PG than others. Insertions in PG and DFR were found throughout the gene regions monitored and, with the exception of one insertion in PG, the junctions between transposon and target were exact. SSI analysis of progeny from the HiDs parents revealed that in some cases the tendency to incur high levels of somatic insertions in PG was inherited. Inheritance of this character is an indication that SSI could be used to direct a search for germinal PG insertions in tomato.

Alcohol Oxidoreductases↗

Antibiotics and garlic clove extract--inhibitory agents of cell wall degrading enzymes.

Four antibiotics were tested against Erwinia causing soft rot of onion (Allium cepa var. aggregatum) of which streptomycin sulphate 90% and tetracycline hydrochloride 10% (streptocycline) recorded the maximum inhibition zone of 27.66 mm. In the enzyme studies the maximum inhibition of pectinlyase (PL), polygalacturonase (PG) and protopectinase production was recorded by the same antibiotic. The antibiotics have a significant influence on the production and activity of cell wall degrading enzymes produced by the plant pathogenic microorganisms. Garlic clove extract was equally effective in inhibiting the growth and enzyme production.

Anti-Bacterial Agents↗

Comparison of expression systems in the yeasts Saccharomyces cerevisiae, Hansenula polymorpha, Klyveromyces lactis, Schizosaccharomyces pombe and Yarrowia lipolytica. Cloning of two novel promoters from Yarrowia lipolytica.

We have compared expression systems based on autonomously replicating vectors in the yeasts Saccharomyces cerevisiae, Schizosaccharomyces pombe, Kluyveromyces lactis, Hansenula polymorpha and Yarrowia lipolytica in order to identify a more suitable host organism for use in the expression cloning method (Dalbøge and Heldt-Hansen, 1994) in which S. cerevisiae has traditionally been used. The capacity of the expression systems to secrete active forms of six fungal genes encoding the enzymes galactanase, lipase, polygalacturonase, xylanase and two cellulases was examined, as well as glycosylation pattern, plasmid stability and transformation frequency. All of the examined alternative hosts were able to secrete more active enzyme than S. cerevisiae but the relative expression capacity of the individual hosts varied significantly in a gene-dependent manner. One of the most attractive of the alternative host organisms, Y. lipolytica, yielded an increase which ranged from 4.5 times to more than two orders of magnitude. As the initially employed Y. lipolytica XPR2 promoter is unfit in the context of expression cloning, two novel promoter sequences for highly expressed genes present in only one copy on the genome were isolated. Based on sequence homology, the genes were identified as TEF, encoding translation elongation factor-1 alpha and RPS7, encoding ribosomal protein S7. Using the heterologous cellulase II (celII) and xylanase I (xylI) as reporter genes, the effect of the new promoters was measured in qualitative and quantitative assays. Based on the present tests of the new promoters. Y. lipolytica appears as a highly attractive alternative to S. cerevisiae as a host organism for expression cloning.

Base Sequence↗

Enzymatic degradation of plant cell wall polysaccharides: the kinetic effect of competitive adsorption.

Insoluble potato dietary fibre, isolated from potato pulp, can be enzymatically hydrolysed with the pectolytic enzyme preparation Pectinex Ultra SP from Novo Nordisk A/S, in order to produce soluble fibre. The soluble fibre has valuable functional properties for the food industry. Cloned monocomponent enzymes from Pectinex Ultra SP (arabinofuranosidase, endoglucanase II, pectin lyase, polygalacturonase I, rhamnogalacturonan acetyl esterase, rhamnogalacturonase a, rhamnogalacturonase b and xylanase I) were added in order to increase the yield. Surprisingly, however, the yield is not increased when any of the monocomponent enzymes are added. To describe the results a new model designated 'the competitive activity adsorption model' is proposed. The model is based on the fact that the enzymes are adsorbed to the substrate before action. A combination of the Langmuir adsorption isotherm and basic enzyme kinetics shows that different enzymes that adsorb competitively will have an inhibitory effect on each other and consequently decrease the hydrolysis rate and thereby the yield. The model has been confirmed by an experiment in which the fibre has been pre-treated with rhamnogalacturonan acetyl esterase.

Acetylesterase↗

Micro-injection of Lygus salivary gland proteins to simulate feeding damage in alfalfa and cotton flowers.

Alfalfa and cotton flowers were pierced with small glass capillaries of an overall size and shape similar to that of Lygus stylets, and injected with small quantities (6 to 100 nL) of solutions that contained Lygus salivary enzymes. Crude and partially purified protein solutions from Lygus heads and isolated salivary glands showed substantial polygalacturonase (PG) activity, as has been previously reported. Following injection with both crude and partially purified protein solutions, as well as with pure fungal and bacterial PGs, flowers of both alfalfa and cotton exhibited damage similar to that caused by Lygus feeding. Injection with the same volume of a buffer control as well as a buffer control containing BSA at a comparable protein concentration (approximately 6 microg/mL) showed no symptoms. These results are consistent with a previously suggested hypothesis that the extensive tissue damage caused by Lygus feeding is primarily due to the action of the PG enzyme on the host tissue, rather than to mechanical damage caused by the insect stylet. Substantial genotypic variation for a PG inhibiting protein (PGIP) exists in alfalfa and cotton. We, therefore, suggest that breeding and selection for increased native PGIP levels, or transformation with genes encoding PGIP from other plant species, may be of value in obtaining alfalfa and cotton varieties that are more resistant to Lygus feeding damage.

Animals↗

Proteomic analysis of changes in the extracellular matrix of Arabidopsis cell suspension cultures induced by fungal elicitors.

A proteomic approach has been applied to investigate changes in the extracellular matrix of Arabidopsis thaliana cell suspension cultures following treatments with two fungal pathogen elicitors, chitosan and extracts of Fusarium moniliforme. The oxidative burst and induction of glutathione S-transferase were used as markers for induction of the pathogen defence response. Changes in the cell wall and culture filtrate proteome were profiled. Proteins whose abundance changed reproducibly were analysed via matrix assisted laser desorption ionisation-time of flight (MALDI-TOF) mass spectrometry (MS). An increase in the level of two classical cell wall proteins (a putative endochitinase and a polygalacturonase inhibiting protein) and two novel proteins (a putative receptor-like protein kinase and a probable apospory-associated protein) were seen at 24 hours following elicitation. The level of an unknown protein and a hypothetical protein, which has some homology to serine carboxypeptidases, were decreased at 24 hours post-elicitation. In the culture filtrate extracts, we identified two pathogen elicitor responsive proteins, a xyloglucan endo-1,4-beta-D glucanases (XEG) and a peroxidase. Using a combination of two-dimensional polyacrylamide gel electrophoresis, immunoblotting with a phosphotyrosine-specific antibody, and MALDI-TOF MS we discovered that spots that represent putative lectin receptor-like kinase, a putative endochitinase and a XEG possess phosphorylated tyrosine residues. The identification of phosphorylated bona fide cell wall proteins and a putative extracellular receptor-like kinase with no transmembrane domain implicate the existence of an extracellular phosphorylation network which could be involved in intercellular communication.

Arabidopsis↗

cDNA cloning and expression of Cry j II the second major allergen of Japanese cedar pollen.

We have isolated and sequenced a cDNA clone coding for Cry j II, the second major allergen of Japanese cedar (Cryptomeria japonica) pollen. A 1.7-kilobase cDNA clone contained an open reading frame coding for a 514-amino acid protein, including a putative signal peptide of 54 amino acid and three potential glycosylation sites. The deduced amino acid sequence of the Cry j II shows significant identities to those of the polygalacturonases associated with fruit-ripening in tomato (40%) and avocado (43%) and found in pollen of maize (34%). Cry j II cDNA product expressed in E. coli was recognized by human IgE from patients suffering from cedar pollinosis, suggesting that recombinant Cry j II might be used as an allergen for the clinical diagnosis of cedar pollinosis.

Amino Acid Sequence↗