Showing papers on "Chitinase published in 1977"

Bacterial chitinase in the stomachs of marine fishes from Yaquina Bay, Oregon, USA

Abstract: The occurrence of chitinase in the stomach contents of Enophrys bison and Platichthys stellatus was investigated. The highest chitinase activity and the greatest percentage of chitinoclastic bacteria in relation to the total bacterial flora were associated with fish whose stomach content was composed primarily of chitinous animals. Stomach contents lacking visible chitin possessed low or no detectable levels of chitinase activity and few chitinoclastic bacteria. Juvenile E. bison treated with chloramphenicol to remove their indigenous bacterial flora had no detectable level of chitinase in their stomach contents while non-treated juveniles showed inducible chitinase activity, indicating the bacterial origin for the chitinase.

Effects of hydroclytic enzymes on plant-parasitic nematodes.

Abstract: Proteases, lipase, and chitinase killed Tylenchorhynchus dubius in vitro and in soil. Tylenchorhynchus dubius was more susceptible to the enzymes than Pratylenchus penetrans. Papain was the most effective protease, and other enzymes were less effective. Heating enzymes to 80 C for 10 min greatly reduced nematicidal effectiveness. Scanning electron micrographs showed that papain and chitinase produced structural changes in the cuticle of T. dubius. Lipase removed a thin outer layer. Papain removed material filling the striata, or furrow, between the horizontal bands. When added to soil, chitinase, lipase, collagenase, and proteases (papain and bromelain) decreased motility of T. dubius populations up to 75%. Bromelain was the most active in soil against T. dubius, and collagenase was the most active in soil against P. penetrans.

Incidence and estimation of chitinase activity associated with marine fish and other estuarine samples

Abstract: A procedure for the determination of chitinase activity was adapted for the seawater environment. Preliminary data indicate that the controlled bacterial environment within the digestive tracts of marine fishes and possibly other marine animals plays a significant role in the decomposition and recycling of chitin. It is estimated in the stomachs of a single population of Enophrys bison (buffalo sculpin) of 1×105 fish that ca. 16 metric tons of chitin could be decomposed annually.

Cell wall studies of Histoplasma capsulatum and Blastomyces dermatitidis using autologous and heterologous enzymes.

Abstract: Enzymes capable of hydrolyzing cell walls of Blastomyces dermatitidis and chemotypes I and II of Histoplasma capsulatum were prepared in the laboratory or obtained from commercial sources. They included chitinases, beta-1,3-glucanases, beta-1,6-glucanase, and Pronase. Monosaccharides and disaccharides of glucose released from the cell walls by the enzymes were determined qualitatively by paper and gas-liquid chromatography, and monosaccharides were quantitated by the latter technique as well. An enzyme system isolated from Streptomyces sp. containing both chitinase and glucanase released maximum amounts of glucose and N-acetylglucosamine from the cell walls of H. capsulatum chemotype I. A chitinase preparation, free of glucanase, from Serratia marcescens released only chitobiose and N-acetylglucosamine from chemotype I cell walls, but the total quantity of N-acetylglucosamine released was about 60% less than that released by the Streptomyces system. A beta-1,3-glucanase from Bacillus circulans hydrolyzed the cell walls of H. capsulatum chemotype I, but a beta-1,6-glucanase failed to release glucose from the same walls. Autolytic enzymes, viz., beta-1,3-glucanases and several glycosidases were detected as constitutive enzymes in both yeast and mycelial phases of B. dermatitidis and H. capsulatum chemotypes I and II. No difference in the amount of activity was found between cell sap and culture filtrate preparations. The beta-glucanases prepared from the Histoplasma and Blastomyces strains were active on the cell walls of the yeast phases of H. capsulatum chemotypes I and II, releasing laminaribiose and glucose, but were essentially inactive on the cell walls of B. dermatitidis. Chitinase, beta-1,6-glucanase, alpha-glucanase, and alpha-glucosidase activities were absent from these fungal enzyme preparations.

Serial enzymatic hydrolysis of cell walls of two serotypes of yeast-form Histoplasma capsulatum with alpha(1 leads to 3)-glucanase, beta(1 leads to 3)-glucanase, pronase, and chitinase.

Abstract: A serial enzymatic hydrolysis procedure for the partial lysis of Histoplasma capsulatum yeast-form cell walls was described, and its application for the differentiation of two serotypes was evaluated. Cell walls were serially digested with alpha(1 leads to 3)-glucanase and beta(1 leads to 3)-glucanse of Cladosporium resinae, then by Pronase, and then by chitinase. The walls of serotype 1, 2, 3 (61.5% digested) were not susceptible to alpha(1 leads to 3)-glucanse, and they contained 30.3% chitin, thus identifying the strain as chemotype 1 (chem 1). Serotype 1, 4 cells walls (51.6% digested) released 27.3% as glucose after treatment with alpha(1 leads to 3)-glucanse and contained 7.8% chitin, compatible with chemotype 2 (chem 2). In addition to quantitating the monomeric products of enzymolysis, I recovered soluble nondialyzable polysaccharide from the digests of both serotypes.

Microbiological and chitinoclastic activities associated with Penaeus setiferus.

Abstract: Analysis of microbiological and chitinase activities relative to the white shrimpPenaeus setiferus, and its chitinoclastic endosymbionts, have demonstrated the relevance of total chitinolytic processes in penaeid biology. Microorganisms may serve as a direct source of nutrients for the animal as well as in the elaboration of extracellularin situ chitinase enzymes. The enzyme produced by the predominant gut bacteria,Beneckea neptuna, is a moderately actively inducible chitinase while the shrimp has an indigenous constitutive chitinase and chitobiase system. Factors of temperature, pH, ion inhibition and reducing sugar ratios have been compared for the bacterial and animal enzymes. This dual enzyme system suggests that metabolic chitin transformation may play a vital role in crustacean metabolism.

Autolysis of Neurospora crassa in different culture conditions and release of β-N-acetyl-glucosaminidase and chitinase

Abstract: Autolysis of fungal mycelium is a complex phenomenon attributed to lytic enzymes contained in the mycelium itself or excreted into the medium. Many studies on physiological changes during autolysis have been carried out ( Lahoz, et al, 1966 , Lahoz and Gonzalez Ibeas, 1968 , Trinci and Righelato, 1970 ), but few accounts of autolysis have referred to the production of lytic enzymes during this process ( Vessey and Pegg, 1973 , Reyes and Byrde, 1973 ). We have found that changes in culture conditions, e.g. flow of air, rate of shake, temperature, influence the degree of autolysis. The comparative autolysis of Neurospora crassa in different culture conditions and the release into the medium of two lytic enzymes, β-N-acetylglucosaminidase and chitinase, are presented here.

Confirmations experimentales du potentiel du complexe bacillus thuringiensis et chitinase pour la repression de la tordeuse des bourgeons de l’epinette, choristoneura fumiferana (lepidoptera: tortricidae)

Abstract: Intensive and systematic laboratory studies conducted under various experimental conditions (larval stage, physiological condition of the insect, temperature, formulation) revealed that non-crystalliferous strains of Bacillus thuringiensis Berliner and B. cereus Frankland and Frankland were equally pathogenic for larvae of Choristoneura fumiferana Clemens as the crystalliferous strain of B. thuringiensis tested. Also the addition of minute quantities of chitinase (10,000 UN/ha) considerably increased the efficiency of commercial preparation of B. thuringiensis against C. fumiferana.At 20°C, B. thuringiensis var. kurstaki provoked a slow septicemia in 3rd instar larvae of C. fumiferana which resulted in 90% larval mortality in 27 days. Under the same experimental conditions, a non-crystalliferous strain of B. thuringiensis (No. 17) and two strains of B. cereus, entomopathogens isolated from C. fumiferana and from a Tachinidae, also caused a slow septicemia resulting in 90% mortality of 3rd instar larvae after 30 to 32 days.Experiments revealed that the symptoms of infection (lethargy, loss of weight) caused by B. thuringiensis + chitinase were far more rapid and pronounced than those provoked by B. thuringiensis alone The commercial preparation 26B prepared by Sandoz-Wander, applied at a rate of 16.8 × 109 BIU/ha caused only 80% mortality of 3rd and 4th stage larvae, while the complex Sandoz + chitinase N.B.C. provoked 100% larval mortality between 9 and 27 days depending upon the experimental conditions used Similar results were obtained with Dipel 36B. For instance, at 20°C Dipel + chitinase N.B.C. provoked 100% mortality of 3rd stage larvae in 9 days, while with Dipel alone, the same level of mortality was reached after 24 days. Also, it was established that C. fumiferana larvae reared on Abies balsamea were far more susceptible to the action of the bacillus than those reared on artificial diet.These results confirmed that addition of chitinase considerably increased the pathogenic properties of B. thuringiensis on C. fumiferana and the low efficiency of the bacillus alone. The addition of chitinase to commercial B. thuringiensis preparations is required and of prime importance in future use of B. thuringiensis for the control of this insect pest.

[Physiological and biochemical properties of Actinomyces kurssanovii, active producter of chitinase].

Abstract: Chitinase biosynthesis by Actinomyces kurssonovii 75 was studied under conditions of periodic cultivation in a laboratory fermenter. The activity of components of the chitinolytic complex correlated with the growth phases of the culture. The activity of chitobiase (beta-N-acetylglucoseaminidase) predominated in the cultural broth in the exponential growth phase of the culture; it decreased later by 40-50 per cent, while the activity of chitinase became maximum. The biosynthesis of chitinolytic enzymes by the growing actinomycete was accompanied with a rapid hydrolysis of demineralized crab shells, and a gradual increase in the pH of the medium to 9.0. A chitinolytic preparation obtained from the supernatant of the cultural broth of Act kurssanovii hydrolysed ground chitin by 70-80 per cent during 5 days. Fe2+ and Ca2+ ions increased the activity of the preparation by 25 and 30 per cent respectively; Mn2+ ions decreased the activity by 40 per cent.

CellWallStudies ofHistoplasma capsulatum and Blastomyces dermatitidis UsingAutologous andHeterologous Enzymes

Abstract: Enzymescapable ofhydrolyzing cell walls ofBlastomyces dermatitidis and chemotypes IandIIofHistoplasma capsulatum were prepared inthelaboratory or obtained fromcommercial sources.Theyincluded chitinases, /8-1,3-glucanases,83-1,6-glucanase, andPronase. Monosaccharides anddisaccharides ofglucosereleased fromthecell walls bytheenzymes were determined qualitatively bypaper andgas-liquid chromatography, andmonosaccharides were quantitated bythelatter technique aswell. Anenzyme systemisolated fromStreptomyces sp.containing bothchitinase andglucanase released maximumamounts ofglucose andN-acetylglucosamine fromthecellwallsofH.capsulatum chemotype I.A chitinase preparation, free ofglucanase, fromSerratia marcescens released onlychitobiose andN-acetylglucosamine fromchemotype Icell walls, butthetotal quantity ofN-acetylglucosamine released was about60% lessthanthatreleased bytheStreptomyces system.A /8-1,3-glucanase from Bacillus circulars hydrolyzed thecell walls ofH.capsulatum chemotype I,but a 8-1,6-glucanase failed torelease glucose fromthesame walls. Autolytic enzymes,viz., /8-1,3-glucanases andseveral glycosidases, were detected as constitutive enzymes inbothyeastandmycelial phases ofB.dermatitidis andH. capsulatum chemotypes IandII.Nodifference intheamountofactivity was foundbetween cell sap andculture filtrate preparations. The/8-glucanases prepared fromtheHistoplasma andBlastomyces strains were active on thecell wallsoftheyeastphases ofH.capsulatum chemotypes IandII,releasing laminaribiose andglucose, butwere essentially inactive on thecell walls ofB. dermatitidis. Chitinase, 3-1,6-glucanase, a-glucanase, anda-glucosidase activities were absent fromthese fungal enzyme preparations. Thecell wallofHistoplasma capsulatum, a dimorphic fungus thatinfects bothmanand other animals, consists predominantly ofchitin andglucan (12-14, 23,24). Based ontheratio of chitin toglucan inthewalls oftheyeast phase, those strains ofH.capsulatum studied todate canbedivided intotwochemotypes, IandII (14). Chemotype Icell walls contain morechitin andless glucan thanchemotype II.Moreover, theevidence suggests that theglucan inchemotypeIIcell walls ispredominantly linked inthe a configuration withfew/8-glucans present, whereas theglucan ofchemotype Iisentirely ,3-linked. Lytic enzymes havebeenusedinthepastto