Production and partial characterization of chitinase from a halotolerant Planococcus rifitoensis strain M2-26

Enhanced biological activity of chitinase immobilized on cobalt metal-organic framework: Isolation, characterization, and potential applications

Chitinase, an enzyme that hydrolyzes glycosidic bonds in chitin, holds significant potential for industrial applications, including biological control, antifungal treatments, and antibiofilm strategies. In this study, chitinase derived from Planomicrobium sp. (PP133202) was immobilized onto a cobalt metal-organic framework (Co-MOF), and its properties were extensively analyzed using various biological, chemical, and physical characterization techniques. The microbial source was identified via 16S rRNA sequencing, and enzyme activity was optimized under submerged conditions using Response Surface Methodology (RSM). Structural and morphological characterization of the chitinase/Co-MOF complex was conducted through FTIR, SEM, TEM, XPS, XRD, EDX, and surface area analyses. The encapsulation efficiency and loading capacity were determined to be 42 % and 20 %, respectively. Notably, the immobilized chitinase exhibited a threefold increase in enzymatic activity compared to its free form. Additionally, the chitinase/Co-MOF complex demonstrated enhanced biological control efficacy, effectively inhibiting Tribolium castaneum and multiple pathogenic microorganisms, including Pseudomonas aeruginosa, Aspergillus flavus, Aspergillus terreus, and Beauveria bassiana. These findings highlight the potential of chitinase/Co-MOF as a promising agent for antimicrobial and pest control applications.

Genome-Wide Mining of Chitinase Diversity in the Marine Diatom Thalassiosira weissflogii and Functional Characterization of a Novel GH19 Enzyme

Chitin represents a globally abundant marine polymer with significant ecological and biotechnological value. β-chitin is an important carbon fixation product of diatoms and has a greater range of applications than α- and γ-chitin. However, there has been a paucity of research on the characterization of chitin-related enzymes from β-chitin producers. In this study, we performed a genome-wide identification of 38 putative chitinase genes in Thalassiosira weissflogii, a key producer of β-chitin. Through comprehensive analyses of phylogenetic relationships, conserved motifs, structural domains, and subcellular localization predictions, we revealed that T. weissflogii possesses evolutionarily distinct GH18 and GH19 chitinase families exhibiting unique motif and domain configurations. Subcellular localization predictions showed that most TwChis were presumed to be located in the chloroplast, with a few being present in the nucleus and extracellular. The enzymatic activity of TwChi2, a GH19 chitinase, showed that TwChi2 was a member of exochitinase (EC 3.2.1.201) with strong thermal stability (40 °C) and broad substrate adaptability of hydrolyzing bipolymer, 1% and 5% colloidal chitin, α-chitin and β-chitin. Altogether, we analyzed the chitinase gene family and characterized a highly active exochitinase from T. weissflogii, which can catalyze the degradation of both chitin polymers and chitin oligosaccharides. The relevant results lay a foundation for the internal regulation mechanism of chitin metabolism in diatoms and provide a candidate enzyme for the green industrial preparation of high-value chitin oligosaccharides.

Extremozymes and compatible solute production potential of halophilic and halotolerant bacteria isolated from crop rhizospheric soils of Southwest Saurashtra Gujarat

Halophiles are one of the classes of extremophilic microorganisms that can flourish in environments with very high salt concentrations. In this study, fifteen bacterial strains isolated from various crop rhizospheric soils of agricultural fields along the Southwest coastline of Saurashtra, Gujarat, and identified by 16S rRNA gene sequencing as Halomonas pacifica, H. stenophila, H. salifodinae, H. binhaiensis, Oceanobacillus oncorhynchi, and Bacillus paralicheniformis were investigated for their potentiality to produce extremozymes and compatible solute. The isolates showed the production of halophilic protease, cellulase, and chitinase enzymes ranging from 6.90 to 35.38, 0.004-0.042, and 0.097-0.550 U ml-1, respectively. The production of ectoine-compatible solute ranged from 0.01 to 3.17 mg l-1. Furthermore, the investigation of the ectoine-compatible solute production at the molecular level by PCR showed the presence of the ectoine synthase gene responsible for its biosynthesis in the isolates. Besides, it also showed the presence of glycine betaine biosynthetic gene betaine aldehyde dehydrogenase in the isolates. The compatible solute production by these isolates may be linked to their ability to produce extremozymes under saline conditions, which could protect them from salt-induced denaturation, potentially enhancing their stability and activity. This correlation warrants further investigation.

Potential application of a fungal co-culture crude extract for the conservation of post-harvest fruits

Fungal plant pathogens are responsible for serious losses in many economically important crop species worldwide. Due to the use of fungicides and the fungi genome plasticity, multi-drug resistant strains are emerging as a new generation of pathogens, causing an expansive range of superficial and systemic plant infections, or new opportunistic fungal pathogens for humans. The group of antagonistic fungi Trichoderma spp. has been widely used to enhance plant growth and for the control of different pathogens affecting crops. Although Neurospora crassa is not a mycoparasitic fungus, its secretion of secondary metabolites with antimicrobial activity has been described. In this work, the effect of crude extract of the monoculture of Trichoderma asperellum T8a or the co-culture with N. crassa as an inhibitory treatment against the fungal pathogens Botrytis cinerea and Fusarium solani was evaluated. The findings demonstrate that the secondary metabolites contained in the T. asperellum crude extract have a clear fungistatic activity against B. cinerea and F. solani. Interestingly, this fungistatic activity highly increases when T. asperellum is co-cultivated with the non-pathogenic fungus N. crassa. Moreover, the co-culture crude extract also showed antifungal activity on post-harvest fruits, and no toxic effects on Murine fibroblast L929 (CCL-1) and murine macrophages RAW 264.7 (TIB-71) were observed. All these results together are solid evidence of the potential of the co-culture crude extract of T. asperellum and N. crassa, as an antifungal agent against phytopathogenic fungi, or post-harvest fruits during the transportation or commercialization time.

Marine enzymes: Classification and application in various industries

Oceans are regarded as a plentiful and sustainable source of biological compounds. Enzymes are a group of marine biomaterials that have recently drawn more attention because they are produced in harsh environmental conditions such as high salinity, extensive pH, a wide temperature range, and high pressure. Hence, marine-derived enzymes are capable of exhibiting remarkable properties due to their unique composition. In this review, we overviewed and discussed characteristics of marine enzymes as well as the sources of marine enzymes, ranging from primitive organisms to vertebrates, and presented the importance, advantages, and challenges of using marine enzymes with a summary of their applications in a variety of industries. Current biotechnological advancements need the study of novel marine enzymes that could be applied in a variety of ways. Resources of marine enzyme can benefit greatly for biotechnological applications duo to their biocompatible, ecofriendly and high effectiveness. It is beneficial to use the unique characteristics offered by marine enzymes to either develop new processes and products or improve existing ones. As a result, marine-derived enzymes have promising potential and are an excellent candidate for a variety of biotechnology applications and a future rise in the use of marine enzymes is to be anticipated.

Potentialities and Characterization of an Antifungal Chitinase Produced by a Halotolerant Bacillus licheniformis

The chitinases are gaining much attention based on their role in the defense against pathogen attacks and harmful insects. The partially chitinase produced by Bacillus licheniformis strain J24 exhibited a large antifungal spectrum, and the highest activity was obtained toward Fusarium species in vitro on PDA and in vivo on corn seeds. The chitinase was inducible by the presence of autoclaved Fusarium conidia in the medium culture and it was active at 70 °C and pH 7 and not affected by the tested chemical agents EDTA and SDS. The nucleotide and amino acid sequences encoding chitinase showed the close phylogenetic relation with chitinase from Bacillus paralicheniformis species. Based on the analysis of the putative domain active, the described chitinase from strain J24 was belonging to the GH family-18 and the novelty of its structure was revealed. Here the combination of functional and structural antifungal extremely chitinase proves its importance in biotechnology area.

Isolation, Identification and Characterization of Rhizobacteria Strains for Biological Control of Bacterial Wilt (Ralstonia solanacearum) of Eggplant in China

Bacterial wilt of eggplant is the most destructive disease caused by Ralstonia solanacearum throughout the world. Eleven bacterial strains with high antagonistic activity were obtained from 245 rhizobacteria. Based on analysis of morphology, 16S rRNA sequences, fatty acid profiles, gyrA and rpoB genes, they were identified as Pseudomonas putida (IMA3), Paenibacillus polymyxa (IMA5), Bacillus cereus (IMA4, IMA7 and IMA11) and the “operational group Bacillus amyloliquefaciens” (IMA1, IMA2, IMA6, IMA8, IMA9 and IMA10). The lipopeptide compounds produced by each strain also were determined. The biocontrol tests demonstrated that co-inoculation by strain IMA5 and the pathogen gave the greatest biocontrol efficiency of 87.0% and 69.2% 30 and 40 days after co-inoculation, respectively. Plant growth promotion tests revealed that IMA5 markedly promoted eggplant growth, enhancing aboveground seedling length and biomass by 60.8% and by 107.6% and underground root length and biomass by 33.0% and 69.2%, respectively. Hence, strain IMA5 could be considered for developing potential biocontrol agents and for promoting plant growth characteristics, to aid the management of the pathogen R. solanacearum in eggplants.

Biochemical and Molecular Screening of Varieties of Chili Plants that are Resistant against Fusarium Wilt Infection

Pakistan holds the position of top chilies producers. So Capsicum annuum L. production in Pakistan should be promoted by combating against diseases. The only solution is to cultivate resistant varieties. Presently six chili varieties were treated with Fusarium oxysporum Schlecht. and screened for the most resistant and the most susceptible varieties. Representative varieties were evaluated for their biochemical and transcriptional profiles to discover the bases of antifungal-resistance. Results concluded that the most resistant variety was “Dandicut” and the most susceptible was “Ghotki”. Tannins, coumarins, flavonoids, phenolics, Riboflavins and saponins were observed in higher quantities in Dandicut as compared to Ghotki. Defense related enzymes i.e. polyphenol oxidase, phenyl ammonia lyase and peroxidase were found in elevated amounts in Dandicut than in Ghotki. Transcriptional results showed that defense related genes i.e. PR2a, acidic glucanase; Chitinase 3, acidic; Osmotin-like PR5 and Metallothionein 2b-like had higher expressional rates in Dandicut. Pearson’s correlation coefficient revealed stronger direct interaction in signal transduction and salicylic acid pathway. Resistance of chili varieties is salicylic acid based. Results obtained from this study not only help to improve chili production in Pakistan but also facilitate variety development operations. Moreover, it also constructed a scale to evaluate innate resistance among varieties.

Recent Advances in Marine Enzymes for Biotechnological Processes

In the last decade, new trends in the food and pharmaceutical industries have increased concern for the quality and safety of products. The use of biocatalytic processes using marine enzymes has become an important and useful natural product for biotechnological applications. Bioprocesses using biocatalysts like marine enzymes (fungi, bacteria, plants, animals, algae, etc.) offer hyperthermostability, salt tolerance, barophilicity, cold adaptability, chemoselectivity, regioselectivity, and stereoselectivity. Currently, enzymatic methods are used to produce a large variety of products that humans consume, and the specific nature of the enzymes including processing under mild pH and temperature conditions result in fewer unwanted side-effects and by-products. This offers high selectivity in industrial processes. The marine habitat has been become increasingly studied because it represents a huge source potential biocatalysts. Enzymes include oxidoreductases, hydrolases, transferases, isomerases, ligases, and lyases that can be used in food and pharmaceutical applications. Finally, recent advances in biotechnological processes using enzymes of marine organisms (bacterial, fungi, algal, and sponges) are described and also our work on marine organisms from South America, especially marine-derived fungi and bacteria involved in biotransformations and biodegradation of organic compounds.

Halophiles, coming stars for industrial biotechnology

Industrial biotechnology aims to produce chemicals, materials and biofuels to ease the challenges of shortage on petroleum. However, due to the disadvantages of bioprocesses including energy consuming sterilization, high fresh water consumption, discontinuous fermentation to avoid microbial contamination, highly expensive stainless steel fermentation facilities and competing substrates for human consumption, industrial biotechnology is less competitive compared with chemical processes. Recently, halophiles have shown promises to overcome these shortcomings. Due to their unique halophilic properties, some halophiles are able to grow in high pH and high NaCl containing medium under higher temperature, allowing fermentation processes to run contamination free under unsterile conditions and continuous way. At the same time, genetic manipulation methods have been developed for halophiles. So far, halophiles have been used to produce bioplastics polyhydroxyalkanoates (PHA), ectoines, enzymes, and bio-surfactants. Increasing effects have been made to develop halophiles into a low cost platform for bioprocessing with advantages of low energy, less fresh water consumption, low fixed capital investment, and continuous production.

Halophilic hydrolases as a new tool for the biotechnological industries

Halophilic micro-organisms are able to survive in high salt concentrations because they have developed diverse biochemical, structural and physiological modifications, allowing the catalytic synthesis of proteins with interesting physicochemical and structural properties. The main characteristic of halophilic enzymes that allows them to be considered as a novel alternative for use in the biotechnological industries is their polyextremophilicity, i.e. they have the capacity to be thermostable, tolerate a wide range of pH, withstand denaturation and tolerate high salt concentrations. However, there have been relatively few studies on halophilic enzymes, with some being based on their isolation and others on their characterisation. These enzymes are scarcely researched because attention has been focused on other extremophile micro-organisms. Only a few industrial applications of halophilic enzymes, principally in the fermented food, textile, pharmaceutical and leather industries, have been reported. However, it is important to investigate applications of these enzymes in more biotechnological processes at both the chemical and the molecular level. This review discusses the modifications of these enzymes, their industrial applications and research perspectives in different biotechnological areas.