Showing papers on "Chitinase published in 1982"
TL;DR: Trichoderma harzianum excreted β-1, 3-glucanase and chitinase into the medium when grown on laminarin and Chitin, respectively, or on cell walls of the pathogen Sclerotium rolfsii as discussed by the authors.
Abstract: Trichoderma harzianum excreted β-1, 3-glucanase and chitinase into the medium when grown on laminarin and chitin, respectively, or on cell walls of the pathogen Sclerotium rolfsii, as sole carbon s...
479 citations
TL;DR: The extracellular chitinase produced by Serratia marcescens was obtained in highly purified form by adsorption-digestion on Chitin this article.
151 citations
TL;DR: An integrated process scheme for conversion of shrimp shell chitin waste to yeast single-cell protein based on these and previous results was designed and analyzed economically, giving a negative after-tax cash flow of $0.06 per kg of wet waste.
Abstract: Study of pretreatment of shrimp processing waste for a chitin bioconversion scheme to produce yeast single-cell protein established conditions for size reduction, deproteination, and demineralization. Enzymatic hydrolysis of pretreated chitin waste achieved 80% conversion in 24 hr. Optimum temperature and pH were determined for maximum chitinase production in submerged culture, using pretreated chitin waste as substrate. An integrated process scheme for conversion of shrimp shell chitin waste to yeast single-cell protein based on these and previous results was designed and analyzed economically, giving a negative after-tax cash flow of $0.06 per kg of wet waste.
93 citations
TL;DR: It could not, however, be conclusively established whether protein and carbohydrate are covalently linked, because the chitinase is resistant to endo-beta-N-acetyl-glucosaminidase.
87 citations
TL;DR: Constitutive chitinases were purified from healthy tomato stem and culture filtrates of a tomato isolate of Verticillium albo-atrum and increased activity in infected tissue was due primarily to increased production of the constitutive endo-enzyme found in healthy tomato stems.
Abstract: Constitutive chitinases were purified from healthy tomato stem and culture filtrates of a tomato isolate of Verticillium albo-atrum Both chitinases hydrolyzed chitin, chitosan and 3,4-dinitrophenyl-tetra- N -acetyl-β- d -chitotetraoside, but the tomato enzyme showed enhanced production of N -acetylglucosamine from chitin in the presence of chitobiase The tomato chitinase, purified to homogeneity, had a molecular weight of 27 000–31000 and functioned as an endo-enzyme The partially purified chitinase from V albo-atrum had a molecular weight of 63 000, appeared to be an exo-enzyme and was unaffected by the addition of chitobiase to the reaction mixture It differed from the tomato enzyme in the hydrolysis of chitobiose and in its inhibition by 2-acetamido-2-deoxy- d -gluconolactone The origin of increased chitinase activity in V albo-atrum -infected tomato stem was investigated by comparing the response of chitinase in extracts from healthy and infected stem to pH and temperature and by examining the patterns of activity in healthy and infected stem extracts after gel isoelectric-focusing The enzymes from healthy and infected stem and from V albo-atrum were also compared during the various purification stages The increased activity in infected tissue was due primarily to increased production of the constitutive endo-enzyme found in healthy tomato stems An additional chitinase similar to the fungal enzyme was also present
84 citations
TL;DR: It is concluded that yeast chitinase is a secretory enzyme, like invertase and acid phosphatase, that appears to be stored in vesicles as a prelude to its secretion into the periplasmic space.
69 citations
TL;DR: In this paper, the role of host and fungal glycosidases in degrading the cell wall of fungal pathogens during infection was discussed in relation to fungal cell wall structure.
Abstract: Tomato stem extracts released glucose, N -acetylglucosamine and other reducing groups from hyphal walls of the wilt pathogen Verticillium albo-atrum during in vitro hydrolysis. Extracts from V. albo-atrum infected stems contained more l,3-β-glucanase, chitinase, β-glucosidase and N -acetyl-glucosaminidase and were more active on purified preparations of mycelial cell wall than were those from healthy stem. Stem extracts from the infected susceptible tomato cv. Craigella contained more activity than extracts from an infected isogenic resistant line. Purified chitinases from both tomato and V. albo-atrum released N -acetylglucosamine from hyphal walls. Neither the tomato endo-l,3-β-glucanase nor the exo-1,3-β-glucanase and β-glucosidase from V. albo-atrum , showed activity individually towards the hyphal wall but mixed enzyme digests containing tomato endo-1,3-β-glucanase in combination either with fungal exo-1,3-β-glucanase or β-glucosidase, liberated large amounts of glucose and other reducing groups. The results are discussed in relation to fungal cell wall structure and the role of host and fungal glycosidases in degrading the cell wall of fungal pathogens during infection.
63 citations
TL;DR: Since some enzymes showed a high level of activity, A. pullulans could possibly be considered a promising source of extracellular lytic enzymes.
Abstract: One hundred and ninety-eight strains of Aureobasidium pullulans were screened for their ability to release extracellular hydrolytic enzymes into the cutural medium. Most of the isolates produced, to a varying extent, enzymes such as amylase, lipase (with different fats as substrates), protease (as caseinolysis and gelatin liquefaction), nucleases (ribonuclease and deoxyribonuclease), urease, and phosphatase. Neither cellulase nor chitinase were produced. Since some enzymes showed a high level of activity, A. pullulans could possibly be considered a promising source of extracellular lytic enzymes.
45 citations
TL;DR: The 'inhibitor' of chit in synthetase previously isolated from the cytosol of Mucor rouxii was found to be a chitinase, which was much more effective against nascent chitins than against preformed chitIn.
42 citations
TL;DR: Chitinase that appears as a single band by electrophoresis was purified from stable fly pupae and has no cation requirements for activity, and a broad pH optimum around 5.5%.
41 citations
TL;DR: It was established that the final intermediate of chitin biosynthesis (UDP-N-acetylglucosamine) was formed in the isolated integuments in the presence of diflubenzuron and polyoxin-D, and it seems likely therefore that both compounds interfere with the final polymerization step of the chit in biosynthesis pathway.
Abstract: Isolated whole integuments from L. cuprina larvae rapidly incorporate radioactivity from both N-acetyl[I-'4C]glucosamine and [1-'4C]glucosamine into alkali-insoluble material, a reaction which does not require preincubation of the tissue with /i-ecdysone. The labelled product was degraded to N-acetylglucosamine during digestion with chitinase, establishing that it consists mainly of chitin. Incorporation was inhibited by polyoxin-D (Iso, 6 x 10- 7 M) and diflubenzuron (Iso, 7 x 10- 7M) but was not inhibited to any marked extent by isoprothiolane, Vetrazin or a-methyl-DOPA. The effectiveness of diflubenzuron as an inhibitor of chitin synthesis in this system (Iso, 7 x 10- 7 M) correlates well with its potency as a larvicide (LDso, 2·1 x 10- 6 M), providing additional support for the proposal that this compound kills larvae by interfering with chitin deposition in the cuticle. Polyoxin-D was much more effective as an inhibitor of chitin synthesis (Iso, 6 x 10- 7 M) than as a larvicide (LDso, 2·0x 10- 5 M). It was established that the final intermediate of chitin biosynthesis (UDP-N-acetylglucosamine) was formed in the isolated integuments in the presence of diflubenzuron and polyoxin-D. It seems likely therefore that both compounds interfere with the final polymerization step of the chitin biosynthesis pathway.
TL;DR: Measurement of enzyme activities in the various fractions of the mycelium revealed that endoglucanase was truly extracellular while β-glucosidase was cell wall bound.
Abstract: A significant increase in the extracellular yield of β-glucosidase was observed when Trichoderma reesei QM 9414 was cultivated on a cellulose medium containing chitin. Measurement of enzyme activities in the various fractions of the mycelium revealed that endoglucanase was truly extracellular while β-glucosidase was cell wall bound. Treatment of Trichoderma mycelium with cell wall degrading enzymes (produced from Trichoderma) led to a release of β-glucosidase from the mycelium. Apparently chitin, in the presence of cellulose, induces the synthesis of chitinase and other cell wall lytic enzymes which promote release of the intramural β-glucosidase into the medium.
TL;DR: The activity of chitinases extracted from various organs of different fish, amphibians and reptiles was estimated as a function of pH by using “native” chITin as substrate, suggesting the existence of three different chit inase types.
TL;DR: In this paper, trichoderma pseudokoningii mycelium was treated sequentially with the following enzymes; (1) lysing enzyme and laminarinase, (2) pronase, and (3) chitinase.
Abstract: Trichoderma pseudokoningii mycelium was treated sequentially with the following enzymes; (1) lysing enzyme and laminarinase, (2) pronase, and (3) chitinase. (1) Removed the outermost amorphous glucan layer and revealed a striated layer which was removed by (2). Microfibrils were exposed and removed by (3). The wall thus has a layered structure comprising glucan, protein and/or glycoprotein, and chitin. Glucan was prepared and subjected to methylation and hydrolysis. 1,3,5,6-Tetra-O-acetyl-2,4-di-O-methyl-D-glucose was identified suggesting that the 1–3 and 1–6 glucans are cross-linked at intervals.