Showing papers on "Chitinase published in 1976"
TL;DR: Results indicate that lysozyme and chitinase are normal components of fish blood and probably they are produced by the granulocytes, white blood corpuscles rich in lysosomes.
Abstract: The enzyme lysozyme (muramidase) has a degrading effect on chitin, but chitinase is more effective in this respect Both enzymes occur in fish, but their distribution and function are poorly known Activities of lysozyme and chitinase were measured in body fluids and tissues of marine fish Lysozyme was estimated by a plate method, chitinase by a viscosimetric method with glycol chitin as substrate pH optima and other characteristics were studied Lysozyme was found in lymphomyeloid (haematopoietic) tissues of chondrichtyan fish (rays, shark, Chimaera monstrosa) and in the plasma and lymph of certain teleosts Chitinase occurred in lymphomyeloid tissues (except thymus) of chondrichthyans and teleosts, and in the plasma and lymph of teleosts The results indicate that these enzymes are normal components of fish blood Probably they are produced by the granulocytes, white blood corpuscles rich in lysosomes The enzymes might have defence functions in fish blood Lysozyme is bacteriolytically active while chitinase possibly offers protection against chitincontaining parasites Very high chitinase activity was found in the pancreas of C monstrosa The pancreatic enzyme probably has a digestive function
96 citations
62 citations
TL;DR: Findings suggest that chitinase is inducible and that Chitin breakdown is regulated by a repressor-inducer mechanism.
Abstract: An Arthrobacter sp. which actively lysed Fusarium roseum was found to liberate chitinase (E.C. 3.2-1.14, chitin glycanohydrolase), an enzyme essential for the hydrolysis of chitin, a major component of fusarial hyphal walls. Factors involved in the production of chitinase were investigated by modifying culture conditions and assaying for enzyme activity. Production occurred on colloidal chitin as well as on native chitin supplemented with yeast extract or peptone. Enzyme production paralleled growth; liberation of enzyme took place during the log phase with the maximum yield being obtained at the stationary phase. Addition of the non-ionic surfactant, polyoxyethylene sorbitan monooleate (Tween 80) increased enzyme yield. An inverse relationship was found between the amount of enzyme produced and the quantity of n-acetyl-glucosamine liberated. The enzyme was generally not produced when grown on various other carbohydrates. These findings suggest that chitinase is inducible and that chitin breakdown is regulated by a repressor-inducer mechanism. Initial hydrolysis rates of colloidal chitin were proportional to the concentration of chitinase used. Optimal pH and temperature for enzyme activity were 4.9 and 50°C, respectively. Purification of the chitinase was obtained by (NH4)2SO4 precipitation followed by DEAE-cellulose and Sephadex chromatography, achieving a 12-fold increase in specific activity.
53 citations
TL;DR: The specific activity of chitobiase is between 16 and 20 nmole/min · mg protein in mass-isolated integument, gut and fat body, whereas chitinase has its highest activity in integument and only a weak activity in fat body.
43 citations
TL;DR: The gastric chitinolytic enzymes of Perodicticus potto are thus ‘true’ chitinases specific of the β -1,4- N -acetylglucosamine linkages in chit in molecule.
36 citations
TL;DR: The release of acid phosphatase and polysaccharide-peptide complexes by hydrolytic enzymes from the surface of the blastospore and mycelial forms of Candida albicans has been examined in cells from 4 h and 18 h cultures and the results correlated with the appearance of the treated cells in the electron microscope.
Abstract: SUMMARY: The release of acid phosphatase and polysaccharide-peptide complexes by hydrolytic enzymes from the surface of the blastospore and mycelial forms of Candida albicans has been examined in cells from 4 h and 18 h cultures and the results correlated with the appearance of the treated cells in the electron microscope. Treatment with dithiothreitol was necessary for the degradative action of the enzymes to occur. Material released by all the treatments used had a similar qualitative composition, but the proportions of mannan, glucan, peptide and acid phosphatase varied with different treatments and with the type of cell examined, 1,3-β-Glucanase was required for major changes in the cell wall to be effected, but a significant amount of material was released with a chitinase preparation containing some protease activity. Protoplasts were obtained from all types of cell using Cytophaga lytic enzyme L1 which had 1,3-β-glucanase and protease activity, but the purified 1,3-β-glucanase and protease prepared from Streptomyces violaceus cultures required the presence of a chitinase before protoplasts were released. The bonding association between the major components which comprise the cell wall, and the spatial distribution of these macromolecules, varies appreciably between the two dimorphic forms and with the age of the culture.
36 citations
TL;DR: Two chitinases (chitinase I and II) which had very similar properties were purified to an ultracentrifugally homogeneous state from the culture broth of this organism by SP-SephadeX and Sephadex G–100 chromatographies.
Abstract: Streptomyces orientalis was selected as a microorganism which produced chitinase having lytic activity on Rhizopus cell wall.Two chitinases (chitinase I and II) which had very similar properties were purified to an ultracentrifugally homogeneous state from the culture broth of this organism by SP-Sephadex and Sephadex G–100 chromatographies.Molecular weights of chitinase I and II were estimated as about 33,000 and 25,000, and isoelectric points as pH 8.80 and 8.65, respectively. Both chitinases were most active at pH values between 5.5 and 6.5, and were stable in the range of pH 6.0 to 8.0 at 40°C for 3 hr. They were stable at temperatures below 50°C for 15 min. Rhizopus cell wall was almost completely degraded by a cooperative action of these chitinases, and a protease and a chitosanase from Bacillus R–4.
32 citations
TL;DR: Chitinase and chitobiase in the moulting fluid of the silkworm, Bombyx mori were eluted with two and three peaks, respectively by fractionation of an ammonium sulfate and on a DEAE-cellulose column.
30 citations
TL;DR: The chitinases were most active at pH values between 5.5 and 6.5, and were stable in the range of pH 6.0 to 8.0 at 40°C for 3 hours as discussed by the authors.
Abstract: Streptomyces orientalis was selected as a microorganism which produced chitinase having lytic activity on Rhizopus cell wall. Two chitinases (chitinase I and II) which had very similar properties were purified to an ultracentrifugally homogeneous state from the culture broth of this organism by SP-Sephadex and Sephadex G-100 chromatographies. Molecular weights of chitinase I and II were estimated as about 33, 000 and 25, 000, and isoelectric points as pH 8.80 and 8.65, respectively. Both chitinases were most active at pH values between 5.5 and 6.5, and were stable in the range of pH 6.0 to 8.0 at 40°C for 3 hr. They were stable at temperatures below 50°C for 15min. Rhizopus cell wall was almost completely degraded by a cooperative action of these chitinases, and a protease and a chitosanase from Bacillus R-4.
16 citations
TL;DR: In this article, a chitinase from Helix pomatia digestive juice was separated and partly purified by gel chromatography and the optimal pH for degradation of p-nitrophenyl-N-acetyl-beta-D-glucosaminide was 3.4.
Abstract: A beta-N-acetylglucosaminidase from Helix pomatia digestive juice was separated and partly purified by gel chromatography. The optimal pH for the degradation of p-nitrophenyl-N-acetyl-beta-D-glucosaminide was 3.4. The molecular weight was around 160 000 and the pI = 4.95. In the same gel chromatography run two chitinase active peaks were also obtained. These chitinase active peaks were also obtained. These chitinases, with molecular weights around 26 000 and 13 000, had somewhat different pH activity curves with optima at 4.2 and 4.3. By isoelectric focusing the first peak with molecular weight around 26 000 was divided in two chitinase active regions with pI at 5.7 and 3.5. The second peak with molecular weight around 13 000 had a pI at 7.3.
Journal Article•
TL;DR: Strains of Bacillus thuringiensis were shown to hydrolyse various forms of chitin around growing colonies on a solid medium in conditions of submerged cultivation on a medium containing demineralized crab shells.
Abstract: Strains of Bacillus thuringiensis were shown to hydrolyse various forms of chitin around growing colonies on a solid medium. In conditions of submerged cultivation on a medium containing demineralized crab shells, Bac. thuringiensis var. caucasicus INMI Arm. 837 manifests the chitinolytic activity at the beginning of the stationary growth phase. The activity of chitinase which is of a constitutive nature increases when the bacterium is cultivated at pH 7.2. The maximum rate of hydrolysis of colloid chitin by chitinase prepared from the cultural broth is displayed at pH 8.0 and 60 degrees C.
TL;DR: Chitinolytic enzymes have been detected in the digestive fluids of seven species of ants, representingFive subfamilies, representing five subfam families, in order to establish relationships between these enzymes and specific ant species.
TL;DR: Cell walls of mature cleistothecia were very electron dense and fungi and bacteria occurred in cell lumina, even at an early stage, and micro-organisms isolated from soil and leaves grew on media containing cell walls from immature and mature samples but only cleared media from the former.
Abstract: Cleistothecia and associated mycelia of Sphaerotheca mors-uvae (Schw.) Berk. at different stages of development and overwintering have been examined by chemical analysis, decomposition by micro-organisms and enzymes, and by electron microscopy. Chemical analysis of purified cell walls showed that immature and mature stages contain 35 and 26% hexosan and 31 and 22% glucan respectively. Galactose and mannose were the only other monosaccharides found in hydrolysates by GLC. Hydrolysates of walls contained about 10% hexosamine, most of which was N -acetylglucosamine. Melanin, some of which was probably associated with glucosamine and protein, comprised 18–20% of the heavily pigmented mature wall. Chitin-degrading micro-organisms isolated from soil and leaves grew on media containing cell walls from immature and mature samples but only cleared media from the former. Chitinase and glucanase released the expected amounts of N -acetylglucosamine and glucose from immature cell walls but unless they were homogenized by ultrasound, mature walls yielded reduced amounts of N -acetylglucosamine. Filtrates of cell-wall media after growth of Penicillium javanicum Szilvinyi or Streptomyces sp. isolated from over-wintered cleistothecia contained chitinase and β -1,3- and β -1,6-glucanases. Only Streptomyces sp. caused complete lysis of pigmented and non-pigmented mycelial cell walls but mature cleistothecial walls were not solubilized by either organism in 13 days. Cell walls of mature cleistothecia were very electron dense and fungi (including an asco-mycete) and bacteria occurred in cell lumina, even at an early stage. Bacteria were also present within the cell walls in mature cleistothecia and sometimes signs of wall lysis occurred around them.
Journal Article•
TL;DR: In this paper, in vitro and in vivo chitin synthesis in Triatoma infestans was studied and the main water-soluble compound obtained was N-acetylglucosamine as demonstrated by chromatographic procedures.
Abstract: In vivo and in vitro synthesis of chitin in Triatoma infestans was studied. For in vivo experiments, [14C] sugars were injected through the abdominal wall. Maximal incorporation of radioactivity into the cuticle was attained immediately after the ecdysis. The identification of in vivo synthesized chitin was performed by the enzymatic hydrolysis of the alkali-insoluble material from the cuticle with Helix chitinase. The main water-soluble compound obtained was N-acetylglucosamine as demonstrated by chromatographic procedures. In vitro synthesis of chitin was carried out with enzymatic crude extracts from Triatoma infestans, and UDP-N-acetylglucosamine was used as "source" of glycosyl moieties. Higher amounts of [14C] N-acetylglucosamine incorporation to chitin than those previously reported by others, were obtained. The identity of the product was confirmed in a similar way as that from in vivo synthesis. Radioactivity was also found in a liposoluble fraction concomitantly with chitin synthesis. This compound had an anionic behavior, was acid labile and had similar chromatographic properties as dolichol pyrophosphate N-acetylglucosamine obtained with pig liver extracts. Knowledge about dolichol phosphate sugars mediated glycoprotein synthesis in eukaryotes, suggests the involvement of this type of N-acetylglucosaminyl-phospholipid in macromolecule "building" even in insects.
Journal Article•
TL;DR: The chitinase biosynthesis was studied during the cultivation of the strain of Serratia marcescens BKM B-851 with a high chitinolytic activity under submerged cultivation of bacterial cells on the medium containing demineralized crab shell extracellular chit inase showed maximum activity on the 3rd day.
Abstract: The chitinase biosynthesis was studied during the cultivation of the strain of Serratia marcescens BKM B-851 with a high chitinolytic activity. Under submerged cultivation of bacterial cells on the medium containing demineralized crab shell extracellular chitinase showed maximum activity on the 3rd day. Cells of S. marcescens BKM B-851 synthesized chitinase as an adaptive enzyme. Chitinase obtained from the culture liquid by ammonium sulphate precipitation was then dialyzed and liophylized. It displayed optimum hydrolysis of colloid chitin at pH 7-8 and 50 degrees C and of native chitin at 30 degrees C.
01 Jan 1976
Journal Article•
TL;DR: The highest activity of chitinase is manifested at pH 7.0 and depends on ionic composition of the buffer, being higher in veronal buffer than in phosphate or tris//HC1 buffers.
Abstract: Actinomyces kurssanovii, a culture producing large amounts of chitinase and chitobiase, was cultivated on a medium of the following composition (%): demineralized crab shells, 3.0; K2HPO4, 0.5; peptone, 0.2; yeast extract, 0.1; MgSO4-H2O, 0.09. The maximum amount of the enzymes was synthesized after growth in a fermenter of the actinomycete during 48 hours. The highest activity of chitinase is manifested at pH 7.0 and depends on ionic composition of the buffer, being higher in veronal buffer than in phosphate or tris//HC1 buffers. The chitinase and chitobiase of the strain decompose completely colloid chitin and chitin in demineralized crab shells with the formation of N-acetyl-D-glucosamine.