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Journal ArticleDOI

Optimization of carbon and nitrogen sources in the medium and environmental factors for enhanced production of chitinase by Trichoderma harzianum

01 Jun 1996-Bioprocess Engineering (Springer-Verlag)-Vol. 15, Iss: 1, pp 13-20
TL;DR: The use of high concentrations of chitin and ammonium sulphate and exclusion of peptone and urea from the medium resulted in the production of higher level of the enzyme, which was maximized to the level of 0.197 U.
Abstract: Statistical design was used to determine the optimal levels of medium components, the optimal initial pH of the enzyme production medium, the temperature of fermentation, age of the organism in the slant growth and the age of the inoculum for the production of chitinase in shake flask fermentations. The use of high concentrations of chitin and ammonium sulphate and exclusion of peptone and urea from the medium resulted in the production of higher level of the enzyme. The optimal concentrations of the medium components were 12.5 kg/m3 and 4.2 kg/m3 for the chitin and ammonium sulphate respectively. The effect of the addition of peptone and urea to the optimized medium was studied. The optimal values of initial pH and temperature were 5.6 and 28 °C respectively. The optimal age of the slant and the inoculum were found to be 105 h and 43 h respectively. The highest level of chitinase before optimization of the above variables was 0.054 U which was maximized to the level of 0.197 U.
Citations
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Journal ArticleDOI
TL;DR: Protease inhibitors, trans-epoxysuccinyl-L-leucylamido-(4-guanidino)butane (E64), antipain hydrochloride, and a mixture of inhibitors, but not pepstatin A, fully or partially nullified the biocontrol effect of T39.
Abstract: The role of protease of Trichoderma harzianum in the biocontrol of Botrytis cinerea was examined. Two isolates of T. harzianum were compared for their ability to produce protease in liquid culture medium and on the surface of bean leaves. The biocontrol agent T. harziaum T39 produced 58 mU/ml of protease and T. harzianum NCIM1185 produced 54 mU/ml on the 5th day of growth in liquid culture medium. On bean leaves, combinations of B. cinerea and T. harzianum isolates were examined for the synthesis of protease. The protease activities were 0.9 and 0.6 mU/ml for T. harzianum T39 and NCIM1185, respectively, and 0.5 mU/ml for B. cinerea alone after 48 h of incubation. In the presence of T. harzianum T39 culture liquid containing protease, a 55% reduction in B. cinerea germination and a 80% reduction in the germ tube length were observed after 17 h of incubation in vitro. When T. harzianum isolates were added to B. cinerea on bean leaves, increased synthesis of protease was observed (1.0 and 1.2 mU/ml for T39 and NCIM1185, respectively). In the presence of T. harzianum NCIM1185 protease, although the rate of germination was reduced, B. cinerea attained 98% germination after 17 h of incubation. The hydrolytic enzymes produced by B. cinerea, endo-polygalacturonase (PG) and exoPG were partially deactivated by protease from the T. harzianum isolates. Carboxymethyl cellulase was deactivated only by protease of NCIM1185. On the surface of bean leaves, the protease (obtained from liquid culture medium of T. harzianum isolates) resulted in 56–100% reduction of disease severity. The culture liquid containing protease synthesized on the surface of bean leaves treated with B. cinerea and with T. harzianum was collected and added to fresh leaves infected by B. cinerea. There was 56–100% and 30–75% reduction of disease severity with liquid droplet collected from the leaves treated with T. harzianum T39 and NCIM1185, respectively. Increased control of disease was obtained by combining the conidia of T. harzianum isolates with protease obtained from culture media. Protease inhibitors, trans-epoxysuccinyl-L-leucylamido-(4-guanidino)butane (E64), antipain hydrochloride, and a mixture of inhibitors, but not pepstatin A, fully or partially nullified the biocontrol effect of T39. T39 was found to be a poor producer of chitinase and β-1,3-glucanase in vitro. These enzymes were not detected on leaves treated with T39. Involvement of protease in biocontrol of B. cinerea is suggested.

248 citations


Cites background from "Optimization of carbon and nitrogen..."

  • ...Protease activity ofT. harzianumincreases when the liquid culture medium contains organic nitrogen sources (Kapat et al., 1996)....

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Journal ArticleDOI
TL;DR: This listing covers the period May 1, 1997 through to June 30, 1997, which roughly corresponds with the British Mycological Society's Special Interest Committees.

211 citations

Journal ArticleDOI
TL;DR: In this article, central composite design experiment is used to study the effect of ozone treatment for acid dye effluents and to optimise the variables such as salt concentration, pH and time, which influence the efficiency of colour and COD removal of dye.

172 citations

Journal ArticleDOI
TL;DR: A brief survey of recent progress in the regulation and cloning of microbial chitinase genes is given and emphasis is placed on the post-translational modification and localization of the recombinant protein in the host.
Abstract: A range of chitinase genes from microorganisms have been cloned and the potential uses of these genetically manipulated organisms are being investigated by various researchers Fungi and yeast are better producers of chitinase than bacteria Since fungi grow at a slower rate, there have been efforts to clone the fungal chitinase genes into fast-growing bacteria This review gives a brief survey of recent progress in the regulation and cloning of microbial chitinase genes Emphasis is placed on the post-translational modification and localization of the recombinant protein in the host Various amino acid domains are present in this protein The mode of catalytic activity of the recombinant protein in comparison to the wild-type protein is discussed in the available literature The different mechanisms involved in the regulation of chitinase genes from various microorganisms is discussed by the researchers The scope of future research and conclusions yet to be obtained in this particular area are also outlined in this review

105 citations

DOI
29 Jan 2002
TL;DR: The current market for biological agents is estimated to be about 1% of the world’s total output for crop protection, but the largest share of this market involves biopesticides marketed for insect control (mainly products based on Bacillus thuringiensis).
Abstract: Despite many achievements in modern agriculture, food crop production continues to be plagued by disease-causing pathogens and pests. In many cases, chemical pesticides effectively protect plants from these pathogens. However, public concerns about harmful effects of chemical pesticides on the environment and human health have prompted a search for safer, environmentally friendly control alternatives (1–3). One promising approach is biological control that uses microorganisms capable of attacking or suppressing pathogens and pests in order to reduce disease injury. Biological control of plant pathogens offers a potential means of overcoming ecological problems induced by pesticides. It is an ecological approach based on the natural interactions of organisms with the use of one or more biological organisms to control the pathogen. Generally, biological control uses specific microorganisms that attack or interfere with specific pathogens and pests. Because of their specificity, different microbial biocontrol agents typically are needed to control different pathogens and pests, or the same ones in different environments. Agriculture benefits, and is dependent on, the resident communities of microorganisms for naturally occurring biological control, but additional benefits can be achieved by introducing specific ones when and where they are needed (4–9). Many agrochemical and biotechnological companies throughout the world are increasing their interest and investment in the biological control of plant diseases and pests. For plant pathogens alone, the current list of microbial antagonists available for use in commercial disease biocontrol includes around 40 preparations (9–11). These are all based on the practical application of seven species of bacteria (Agrobacterium radiobacter, Bacillus subtilis, Burkholderia cepacia, Pseudomonas fluorescens, Pseudomonas syringae, Streptomyces griseoviridis, Streptomyces lydicus) and more than 10 species of fungi (Ampelomyces quisqualis, Candida oleophila,Coniothyrium minitans, Fusarium oxysporum,Gliocladium virens, Phlebia gigantea, Pythium oligandrum, Trichoderma harzianum, and other Trichoderma species). The current market for biological agents is estimated at only $500 million, which is about 1% of the world’s total output for crop protection. The largest share of this market involves biopesticides marketed for insect control (mainly products based on Bacillus thuringiensis

99 citations

References
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Journal Article
TL;DR: Procedures are described for measuring protein in solution or after precipitation with acids or other agents, and for the determination of as little as 0.2 gamma of protein.

289,852 citations


"Optimization of carbon and nitrogen..." refers methods in this paper

  • ...The mixture was centrifuged at 4000 rev/min and 1 cm 3 of the supernatent was taken for tyrosin assay using Folin-phenol method [ 23 , 24]....

    [...]

Journal ArticleDOI

25,389 citations


"Optimization of carbon and nitrogen..." refers methods in this paper

  • ...After the incubation, products released from the hydrolysis of chitin were estimated as reducing sugar using N-acetyl-D-glucosamine as the standard for the Miller's method [ 22 ]....

    [...]

Book ChapterDOI
TL;DR: The work described in this article is the result of a study extending over the past few years by a chemist and a statistician, which has come about mainly in answer to problems of determining optimum conditions in chemical investigations, but they believe that the methods will be of value in other fields where experimentation is sequential and the error fairly small.
Abstract: The work described is the result of a study extending over the past few years by a chemist and a statistician. Development has come about mainly in answer to problems of determining optimum conditions in chemical investigations, but we believe that the methods will be of value in other fields where experimentation is sequential and the error fairly small.

4,359 citations


"Optimization of carbon and nitrogen..." refers methods in this paper

  • ...The central composite design [18, 19 ] was followed to optimize these variables....

    [...]

Journal ArticleDOI

2,808 citations


"Optimization of carbon and nitrogen..." refers methods in this paper

  • ...The optimization was carried out by an iterative procedure [26] which determine the point at which the function is maximized....

    [...]

Journal ArticleDOI
TL;DR: In this article, the authors summarized research into the existing methods for the quantitative determination of tyrosine and tryptophane in proteins, including the Folin-Looney method, which is based on reaction of a phosphotungstic phosphomolybdic acid in a phenol solution.

2,527 citations