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Showing papers on "Chitinase published in 1978"


Journal ArticleDOI
TL;DR: Experimental results indicate that Serratia marcescens QMB1466 is suitable for use in the proposed bioconversion of shellfish chitin wastes to single-cell protein of value in animal or aquaculture feed formulations or to other products.
Abstract: A process was conceptualized for bioconversion of shellfish chitin wastes to single-cell protein of value in animal or aquaculture feed formulations or to other products. An extracellular chitinase enzyme system obtained by a submerged culture of microorganisms is contacted with the chitin waste, hydrolyzing it to smaller sugar units. The hydrolysate is converted to a marketable product. Experimental results indicate that Serratia marcescens QMB1466 is suitable for use in the proposed process. Hydrolysis of various chitinous waste preparations shows the culture filtrate to be effective in decomposing the substrate. For crude preparations, hydrolysis slows after approximately 40 hr. Colloidal chitin is almost completely dissolved after 60 hr.

81 citations


Journal ArticleDOI
TL;DR: In germinating spores of the parasitic fungus, Aphanomyces astaci, chitinase was first demonstrated shortly before the germ-tube began to branch, in contrast to protease which was present in both ungerminated and germinated spores.
Abstract: In germinating spores of the parasitic fungus, Aphanomyces astaci, chitinase was first demonstrated shortly before the germ-tube began to branch, in contrast to protease which was present in both ungerminated and germinated spores. The time at which chitinase would be required when this fungus penetrates the crayfish cuticle is correlated with that of the in vitro production of chitinase.

47 citations


Journal ArticleDOI
TL;DR: The total soluble proteins and the fresh weights of the integument of the abdomina increase during the fifth larval instar about fivefold and slightly decrease before the next exuviation and decrease just before the ecdysis.

33 citations


Journal ArticleDOI
TL;DR: During the molt of Manduca, old cuticle chitin is rendered competent to serve as chit inase substrate in a reaction attributable to trypsin-like proteolytic activity of molting fluid.

19 citations


Journal ArticleDOI
TL;DR: Bioassays of V instar spruce budworm larvae against seven levels of Thuricide ® at four levels of chitinase corresponding to 0, 22, 220, and 2200 nephelometric units/U.S. gallon showed no effect of ch itinase on LC 50 or slope of the regression line was observed.
Abstract: The addition of chitinase at the rate of 1000–4000 nephelometric units/U.S. gallon to Bacillus thuringiensis insecticide for use against spruce budworm has been advocated. Bioassays of V instar spruce budworm larvae against seven levels of Thuricide ® at four levels of chitinase corresponding to 0, 22, 220, and 2200 nephelometric units/U.S. gallon were conducted by placing larvae on balsam fir foliage ( Abies balsamea ) dipped in appropriate dilutions of Thuricide ® with chitinase. Mortality was assessed 6 days later. An additional replicated assay at a relatively massive dose of chitinase, 33,000 nephelometric units/U.S. gallon, was compared simultaneously with a 0 chitinase control. The data were homogeneous and linear by statistical standards. No effect of chitinase on LC 50 or slope of the regression line was observed.

5 citations



01 Jan 1978
TL;DR: The knowledge of the biochemical mode of action of I-(4-chlorophenyl)-3-(2,6-difluorobenzoyl)urea (diflubenzuron) is presented, explaining the insecticidal effect, together with other effects reported in the literature.
Abstract: The knowledge of the biochemical mode of action of I-(4-chlorophenyl)-3-(2,6-difluorobenzoyl)urea (diflubenzuron) is presented, explaining the insecticidal effect. Like its structural analog, 1-(2,6-dichlorobenzyl)-3-(3,4-dichlorophenyl)urea (Du 19111), it inhibits chitin synthesis in the cuticle of larvae. Virtually complet)e inhibition was demonstrable 15 min after the application of diflubenzuron. Neither diflubenzuron nor Du 19111 has any effect upon chitinase act,ivity either in viva or in vitro. The insecticidal effect upon the cuticle, therefore, must be explained as an inhibition of chitin synt,hesis and not as an activation of chitin degradat,ion. In contrast to the action of Du 19111, no accumulation of IV-acetylglucosamine occurs upon treatment of larvae with diflubenauron. Similarities and differences in the mode of action of both compounds are discussed, together with other effects reported in the literature.