Transcriptional and Translational Characterization of Rice Chitinase Genes

Albeit Metarhizium anisopliae is the best-characterized entomopathogenic fungus, the role of some hydrolytic enzymes during host cuticle penetration has not yet been established. Three chitinase genes (chit1, chi2, chi3) from Metarhizium have already been isolated. To characterize the chitinase coded by the chit1 gene, we expressed the active protein (CHIT42) in Escherichia coli using a T7-based promoter expression vector. The recombinant protein, CHIT42, is active against glycol chitin and synthetic N-acetylglucosamine (GlcNAc) dimer and tetramer substrates. These activities suggest that the recombinant CHIT42 acts as an endochitinase.Key words: Metarhizium anisopliae, chitinases, chit genes, recombinant protein, enthomopathogenic fungi.

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Characterization of chitinase genes orginated from Serratia marcescens and their additive insecticidal activities to Bacillus thuringiensis strains

Current Opinion in Biotechnology ◽

10.1016/j.copbio.2011.05.247 ◽

2011 ◽

Vol 22 ◽

pp. S82

Author(s):

Arzu Ozgen ◽

Remziye Nalcacioglu ◽

Kazim Sezen ◽

Zihni Demirbag

Keyword(s):

Bacillus Thuringiensis ◽

Serratia Marcescens ◽

Chitinase Genes ◽

Insecticidal Activities

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Molecular Characterization of E. Histolytica Strains Based on the Serine Rich Entamoeba Histolytica Protein (Srehp) And Chitinase Genes.

10.21203/rs.3.rs-665084/v1 ◽

2021 ◽

Author(s):

Renay Ngobeni ◽

Amidou Samie

Keyword(s):

South Africa ◽

Molecular Characterization ◽

Significant Influence ◽

Genetic Heterogeneity ◽

Chitinase Gene ◽

Genetic Profile ◽

Genetic Characteristics ◽

Stool Samples ◽

Chitinase Genes

Abstract BACKGROUND: Even though E. histolytica is recognized as an effective pathogen, what determines the outcome of this infection is still not well understood. The present study was carried out to determine the genetic characteristics of E. histolytica isolates from two different regions in South Africa. METHOD: Diarrheal and non-diarrheal stool samples were collected from patients of all ages from Giyani and Pretoria. Different PCR protocols were used to identify E. histolytica and amplify the serine rich E. histolytica protein (SREHP) and chitinase genes. The profiles obtained were compared among the different samples.RESULTS: Out of 111 stool samples collected, 51 were positive by either PCR or microscopy and 14 samples were positive by both methods. The serine- rich E. histolytica protein was amplified in 26 samples. Out of the 26 samples (19) different SREHP profiles were obtained. SREHP #2 was obtained in 5 different samples, 4 from Pretoria and 1 from Giyani (2 diarrheal and 3 non-diarrheal). The chitinase gene was amplified from 51 samples and 22 different chitinase profiles were obtained. Of all the profiles, profile #4 was found in 6 different isolates, 5 from Giyani and 1 from Pretoria (3 symptomatic and 3 asymptomatic). However, profile # 18 was only found in formed stools from Giyani. CONCLUSIONS. The results obtained in this study have further confirmed the genetic heterogeneity of E. histolytica for the SREHP and chitinase genes which might have a significant influence in the outcome of amebic infection, depending on the genetic profile of the infecting strain.

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Transfer of a plant chitinase gene into a nitrogen-fixing Azospirillum and study of its expression

Canadian Journal of Microbiology ◽

10.1139/w04-039 ◽

2004 ◽

Vol 50 (7) ◽

pp. 509-513 ◽

Cited By ~ 3

Author(s):

Jayaraman Jayaraj ◽

Subbaratnam Muthukrishnan ◽

George H Liang

Keyword(s):

Azospirillum Brasilense ◽

Pathogenic Fungus ◽

Chitinase Activity ◽

Chitinase Gene ◽

Cell Protein ◽

Broad Host Range ◽

Nitrogen Fixing ◽

Rice Chitinase ◽

Chitinase Genes

Azospirillum is used extensively in rice and other cereal crops as a biofertilizer. There is a substantial opportunity to improve the efficiency of this bacterium through the transfer of genes of agricultural importance from other organisms. Chitinases are antifungal proteins, and expression of chitinase genes in Azospirillum would help to develop strains with potential antifungal activities. So far there are no reports about transfer of plant genes into Azospirillum and their expression. The present study was aimed at expressing an antifungal gene (a rice chitinase) of plant origin in Azospirillum brasilense. A rice chitinase cDNA (RC 7) that codes for a 35 kDa protein was subcloned into a broad host range plasmid pDSK519 under the control of LacZ promoter. The plasmid was mobilized into the nitrogen-fixing bacterium, Azospirillum brasilense strain SP51eFL1, through biparental mating. The conjugation frequency was in the range of 35–40 × 10–6. The transconjugants grew in nitrogen-free media and fixed gaseous nitrogen in vitro. However, their growth and nitrogen-fixing ability were slightly less than those of the wild-type. Expression of the protein was demonstrated through western blotting of the total cell protein, which detected a 35 kDa band that was immuno-reactive to a barley chitinase antibody. The cell lysates also hydrolyzed various chitin substrates, which resulted in release of free sugars demonstrating the chitinase activity of transconjugants. The expressed protein also had antifungal activity as demonstrated by inhibition of growth of the plant pathogenic fungus, Rhizoctonia solani.Key words: Azospirillum-transformation, rice chitinase gene, protein expression, chitinase activity.

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