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This study evaluated the efficacy of entomopathogenic fungi (EPF) as biocontrol agents against aphids, whiteflies and western flower thrips. The research employed a leaf disc bioassay with various conidia concentrations to determine lethal concentration (LC) and time (LT) for pest eradication. Additionally, the study assessed the activity of cuticle-degrading enzymes produced by EPF (Chitinase, Protease, and Lipase) to understand their pathogenic mechanisms. Molecular identification using ITS region of 18S rDNA identified virulent isolates. Results indicated that four isolates, ENPF-16, 24, 41, and 60, achieved significant mortality rates (95% to 100%) at a concentration of 1x10⁸ conidia/mL after nine days. Akanthomyces sp. (ENPF-41) exhibited the highest enzyme activity, followed by Beauveria sp. (ENPF-60). The virulent fungal isolates were identified as Beauveria bassiana and Akanthomyces lecanii. Among EPFs, Akanthomyces lecanii (MT997935) displayed greater virulence against all three test insects with lower LC₅₀ and LT₅₀ values compared to other EPFs. In summary, all fungal isolates induced mortality in the tested pests, but their effectiveness varied. Akanthomyces lecanii (MT997935) emerged as a promising biocontrol candidate due to its broad host range and strong virulence.
 

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The chitinase producing ability of Pseudomonas fluorescens strains viz., PF1, PB2 and FP7 was evaluated in a culture medium with and without a chitin source. The addition of 1% (v/v) chitin in culture medium significantly increased the bacterial population and chitinase activity. Among three strains tested, FP7 responded well to the addition of chitin by producing 31.2% increased chitinase in culture. Western blot analysis with chitinase antibody detected six and five chitinase isoforms in culture inoculated with FP7 and PF1, respectively.

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The trend toward sustainable development of the environment and economy has led to a large-scale debate on the use of seafood wastes. In recent years shrimp has been a major part of the food industry. The accumulated waste of shrimp without proper use has resulted in the destruction of the resources and problems of waste disposal and environmental pollution. Shrimp waste fermentation with microorganisms is a method for recovering biologically active material. Bacterial chitinase is considered as a degenerate enzyme .In this study, chitin degrading bacteria were isolated from different environment and then the most efficient strain was selected. The isolate identified by Microscopic, physiological and molecular characteristics and sequencing the 16SrRNA gene and compared with the Bacillus licheniformis strain, the highest rate of chitinase has been reported so far. The isolated strain identified as Bacillus altitudinis can ferment shrimp shell as the only sources of energy and produce high-temperature chitinase, with a 5.1 U/mL activity of over a period of 4 days, and 65.6 mg/l protein on semisolid shrimp shell. While it does not grow on the agar under normal conditions, therefore, its use can't cause pollution to the environment. As a result, the activity of chitinase, its simple and inexpensive method of concentration by heat, high enzyme resistance at high temperatures, activity in a wide range of pH and the use of cheap shrimp shell substrate show the superior functional quality of this strain in shrimp shell fermentation.
 

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Chitinases are essential enzymes in crustaceans that play an important role in the molting cycle and digestion of chitin. Based on the present study, the chitinase encoding cDNA of Penaeus mergueinsis with a length of 1440 bp containing 467 amino acids was sequenced by PCR and then its phylogenetic and bioinformatics analysis was performed. The new sequence was registered in the gene bank with the accessition number MT250539 and the molecular weight of the protein resulting from this sequence was predicted to be 51.84 KDa and the theoretical isoelectric point of 4.79. Comparison of amino acid sequences among penaeid chitinases showed the highest identification (about 97 to 92%) with P. mondon chi-3, F. chinensis, P. vannamei and P. japonicus chi-3, respectively. Phylogenetic studies showed that chitinase in the present study belongs to group 3 chitinases. Revealed protein pattern analyzes showed that chitinase from P. mergueinsis contained the catalytic domain Glyco-18 at position 2-347, a chitin-binding site of pritrophin A at position 403-456, a disulfide bridge formed by two cysteines at position 436-421 is a chitin-binding domain type 2, active site (¹¹7FDGLDMDWE¹²⁵), a proline / threonine-rich region at positions 376-412, and a putative N-glycosylation site at position 427-424 (NTSG). The present study shows that the P. mergueinsis sequence contains active chitinase motifs similar to previously sequenced chitinases, and in the case of cloning, expression and purification probably has functional and structural features similar to the enzymes of the above species.

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Trichoderma species are known as effective agents used for biological control of plant pathogenic fungi. The Trichoderma harzianum and its mutant isolates were cultured and their traits including, mycelial growth, antagonistic activity and extracellular proteins and enzymes production (Chitinase and Cellulase) were investigated to select the most effective mutant isolates against plant pathogenic fungus Rhizoctonia solani. Also, the purity and composition of enzyme-rich protein samples were evaluated under denaturing gel electrophoresis. This study clearly showed the possibility of improving mycelia growth rate (from 1.18 to 1.33 cm d^-1), the antagonistic capability of Trichoderma (from 54.9% growth inhibition of R. solani to 66%), extracellular proteins and enzymes production for biological control of plant diseases through mutation with γ-radiation. Also, compared to wild type strain, protein production in the mutant isolates increased. Moreover, the highest specific chitinase enzyme activities were observed in mutant isolates T. h M8 (42.48 U mg^-1) and T. h M15 (38.25 U mg^-1). Trichoderma mutant of T. h M8 maintained higher mycelia growth rate and higher ability to inhibit growth of R. solani. The SDS-PAGE profiles had several enzyme protein bands such as CelloBioHydrolases (CBHs), EndoGlucanases (EGs), β-Glucosidases (BGLs), endochitinases, and β-(1, 4)-N-acetyl glucoaminidases. SDS-PAGE analysis indicated the presence of different protein bands in the range of 10.5 to 245 KDa. Interestingly, expression of chitinase in 95 percent of mutants was higher than wild type of T. harzianum. The results showed that gamma mutation could increase the efficiency and amount of enzymes in T. harzianum, while these enzymes are involved in antagonistic properties of T. harzianum.