Purification and properties of extracellular chitinases from the parasitic fungus Isaria japonica

Asiatic citrus psylla, Diaphorina citri, Kuwayama (Hemiptera: Liviidae) is an economic pest of citrus groves and a vector of the bacterium, Candidatus Liberibacter spp., one of the causative agents of citrus greening. In order to estimate the infectivity of six different isolates of Beauveria bassiana, Metarhizium anisopliae and Isaria fumosorosea, fungal bioassay was performed on the adults of D. citri. Adults of D. citri were treated individually with 1 × 10 5 , 1 × 10 6 , 1 × 10 7 , 1 × 10 8 , 2 × 10 8 spores/mL fungal concentrations by the immersion method. Subsequent to fungal bioassay, treated D. citri were used to determine the levels of esterase and glutathione S-transferases (GST) enzymes over a period of 3-7 days. The mortality results suggest that I. fumosorosea isolates (If-02) caused 82.2% mortality on the seventh day of treatment. However, B. bassiana isolate (Bb-08) with lowest LC 50 (1.4 × 10 7 spores/mL) proved to be highest potential isolate against D. citri. Biochemical determination of esterase and GST activity assay showed significant differences in activities after infection of fungi. Significantly high activity of esterase was observed by Bb-01 (27.0 unit per mg protein) on the seventh day, while Ma-11.1 and If-2.3 (16.9 and 36.3 unit per mg protein) on the third day post treatment. However, maximum GST's activity was showen by isolates Bb-08,Ma-M 2 and If-2.3 (37.6, 1.40 and 10.9 unit per mg protein) on the third day. The current investigation will help to explore the relations between the insect defense system and entomopathogenic fungi. Moreover, the determination of enzymatic activities will be useful for selecting the most pathogenic isolates.

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“…Comparable results were documented with B. bassiana , M. anisopliae and Verticillium lecanii isolates (Kawachi et al . 2001).…”

Section: Discussionmentioning

confidence: 99%

Biochemical analysis and pathogenicity of entomopathogenic fungi to Diaphorina citri Kuwayama (Hemiptera: Liviidae)

Naeem

Freed

Akmal

2020

Entomological Research

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“…The chitinase from Isaria japonica lost 0% of its activity at 50oC (Kawachi et al 2001). The chitinase from Aspergillus fumigatus lost 30% of its activity after 60 minutes of heating at 55°C (Xia et al 2001).…”

Section: Discussionmentioning

confidence: 99%

Purification, characterization and structural determination of chitinases produced by Moniliophthora perniciosa

Galante

Taranto

Koblitz

et al. 2012

An. Acad. Bras. Ciênc.

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The enzyme chitinase from Moniliophthora perniciosa the causative agent of the witches' broom disease in Theobroma cacao, was partially purified with ammonium sulfate and filtration by Sephacryl S-200 using sodium phosphate as an extraction buffer. Response surface methodology (RSM) was used to determine the optimum pH and temperature conditions. Four different isoenzymes were obtained: ChitMp I, ChitMp II, ChitMp III and ChitMp IV. ChitMp I had an optimum temperature at 44-73°C and an optimum pH at 7.0-8.4. ChitMp II had an optimum temperature at 45-73°C and an optimum pH at 7.0-8.4. ChitMp III had an optimum temperature at 54-67°C and an optimum pH at 7.3-8.8. ChitMp IV had an optimum temperature at 60°C and an optimum pH at 7.0. For the computational biology, the primary sequence was determined in silico from the database of the Genome/Proteome Project of M. perniciosa, yielding a sequence with 564 bp and 188 amino acids that was used for the three-dimensional design in a comparative modeling methodology. The generated models were submitted to validation using Procheck 3.0 and ANOLEA. The model proposed for the chitinase was subjected to a dynamic analysis over a 1 ns interval, resulting in a model with 91.7% of the residues occupying favorable places on the Ramachandran plot and an RMS of 2.68. Key words:Chitinase, Moniliophthora perniciosa, kinetic characterization, purification, isoenzymes, heat stability, 3D structure, comparative modeling.

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“…A chitinase with a 43-kDa molecular weight has also been isolated from T. harzianum [29]. Isaria japonica species produce two chitinases, P-1 and P-2, with molecular weights of 43.273 kDa and 31.134 kDa, respectively [30]. Souza et al [31] purified a 43-kDa endochitinase from Colletotrichum gloeosporioides.…”

Section: Digital Signaturementioning

confidence: 99%

Chitinolytic fungi from the Birjand plain of Southern Khorasan Province in Eastern Iran

Laein

Mohammadi

2018

Acta Mycol

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Fungal chitinases play important roles in the decomposition of wastes, mycoparasitism, and biocontrol of nematodes and plant pathogens through chitin biodegradation. This study was conducted during 2013-2017 to investigate the presence of chitinase genes in Trichoderma and Clonostachys species from the Birjand plain, and to evaluate their ability to degrade chitin. Fungal spores and soil suspensions were cultured on minimal medium containing 1% colloidal chitin from crab bodies to isolate chitinolytic fungi. Chitinolytic ability of the isolates was evaluated on this medium by staining with 1% Lugol's iodine solution and screening for the production of a bright halo around the colonies. Fifty-two isolates capable of degrading chitin were recovered. DNA extracted from the isolates was amplified using Chit2 or DECH degenerative primers that are related to the chitinase gene, and their sequences were aligned using the NCBI GenBank database. The Chit2 and DECH primers amplified 600-bp and 250-bp fragments, respectively, and according to sequence alignment, the isolates had sequences similar to that of the chi18 chitinase genes. Morphological and molecular characterization allowed identifying the isolates as belonging to the species Trichoderma harzianum (n = 41), T. longibrachiatum (n = 1), T. virens (n = 3), T. brevicompactum (n = 1), Clonostachys rosea (n = 5), and C. rogersoniana (n = 1), some of which may potentially be used as biocontrol agents of pathogenic nematodes and fungi. This is the first report of isolation of fungi capable of chitin biodegradation from the South Khorasan Province in Eastern Iran.

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Purification and properties of extracellular chitinases from the parasitic fungus Isaria japonica

Cited by 12 publications

References 12 publications

Biochemical analysis and pathogenicity of entomopathogenic fungi to Diaphorina citri Kuwayama (Hemiptera: Liviidae)

Biochemical analysis and pathogenicity of entomopathogenic fungi to Diaphorina citri Kuwayama (Hemiptera: Liviidae)

Purification, characterization and structural determination of chitinases produced by Moniliophthora perniciosa

Chitinolytic fungi from the Birjand plain of Southern Khorasan Province in Eastern Iran

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