Chitosan nanoparticles augmented indole-3-acetic acid production by rhizospheric Pseudomonas monteilii.

Rhizospheric Pseudomonas spp. are widely used for upgrading sustainable agriculture because of their ability to execute multifaceted plant beneficial functions. In the current study, chitosan nanoparticles (CNPs) were used to analyze their effect on plant beneficial properties of rhizospheric Pseudomonas monteilii. The CNPs were characterized by transmission electron microscopy (TEM) and dynamic light scattering (DLS) analysis. The impact of CNPs on indole-3-acetic acid (IAA) production of P. monteilii was analyzed and quantified by spectrophotometric and confirmed high-performance liquid chromatography analysis. This revealed the beneficial effect of CNPs (1 mg/ml) by enhancing the IAA production of P. monteilii. In planta effect of varied bacterial IAA production was further demonstrated in Vigna unguiculata. Here, enhancement in shoot length (35.79 ± 0.37 cm), leaf number (7 ± 0.54), and fresh weight (3.07 ± 0.11 g) were observed in the plants treated with the culture filtrate collected from P. monteilii cultivated with 1 mg/ml CNPs. The results of the study highlight the beneficial effect of the CNPs to augment the rhizobacterial functioning by inducing the expression of plant beneficial properties.

Chitosan and Gold Nanoparticles Supplementation for Augmentation of Indole-3-Acetic Acid Production by Rhizospheric Pseudomonas aeruginosa and Plant Growth Enhancement.

The present study has been focused to evaluate the effect of chitosan nanoparticles (CNPs) and gold nanoparticles (AuNPs) on the phytohormone production by rhizospheric Pseudomonas aeruginosa. The gold nanoparticles were synthesized biologically and characterized by UV-Visible spectrophotometry, transmission electron microscopy, and X-ray diffraction analysis. The indole-3-acetic acid (IAA) production by P. aeruginosa supplemented with CNPs and AuNPs was quantified by using Salkowski's method and confirmed by high-performance liquid chromatography (HPLC) analysis. This revealed the effect of 5 mg/mL CNPs and 100 µg/mL AuNPs to enhance the IAA production by P. aeruginosa. By Salkowski's method, 07.16 ± 0.28 and 09.56 ± 0.28 µg/mL of IAA could be detected in the samples prepared from P. aeruginosa supplemented with 5 mg/mL CNPs and 100 µg/mL AuNPs, respectively. HPLC analysis also confirmed the production of IAA by P. aeruginosa. The CNPs and AuNPs-supplemented P. aeruginosa was also found to have enhancement effect on the shoot length (25.25 ± 0.85 cm and 26.57 ± 0.73 cm) and fresh weight (0.94 ± 0.09 g and 0.96 ± 0.09 g) of Vigna unguiculata plants, which highlight the significance of the study and the agricultural promises of nanomaterials-supplemented rhizobacteria.

Harnessing the Natural Pool of Polyketide and Non-ribosomal Peptide Family: A Route Map towards Novel Drug Development.

The emergence of communicable and non-communicable diseases has posed a health challenge for millions of people worldwide and is a major threat to the economic and social development in the coming century. The occurrence of the recent pandemic, SARS-CoV-2, caused by lethal severe acute respiratory syndrome coronavirus 2, is one such example. Rapid research and development of drugs for the treatment and management of these diseases have become an incredibly challenging task for the pharmaceutical industry. Although, substantial attention has been paid to the discovery of therapeutic compounds from natural sources having significant medicinal potential, their synthesis has made a slow progress. Hence, the discovery of new targets by the application of the latest biotechnological and synthetic biology approaches is very much the need of the hour. Polyketides (PKs) and non-ribosomal peptides (NRPs) found in bacteria, fungi and plants are a diverse family of natural products synthesized by two classes of enzymes: polyketide synthases (PKS) and non-ribosomal peptide synthetases (NRPS). These enzymes possess immense biomedical potential due to their simple architecture, catalytic capacity, as well as diversity. With the advent of the latest in-silico and in-vitro strategies, these enzymes and their related metabolic pathways, if targeted, can contribute highly towards the biosynthesis of an array of potentially natural drug leads that have antagonist effects on biopolymers associated with various human diseases. In the face of the rising threat from multidrug-resistant pathogens, this will further open new avenues for the discovery of novel and improved drugs by combining natural and synthetic approaches. This review discusses the relevance of polyketides and non-ribosomal peptides and the improvement strategies for the development of their derivatives and scaffolds, and how they will be beneficial for future bioprospecting and drug discovery.

Application of Encapsulated Bacillus licheniformis Supplemented with Chitosan Nanoparticles and Rice Starch for the Control of Sclerotium rolfsii in Capsicum annuum (L.) Seedlings.

Rhizosphere encourages the survival and functioning of diverse microbial communities through the influence of plant roots. Likewise, the rhizobacterial functioning contribute to the growth and productivity of crop plants significantly. With the advancement of nanotechnology, the nanoparticles can expect to augment the performance of plant beneficial microorganisms including the rhizobacteria and hence have the promise to boost sustainable agricultural practices. In the present study, Bacillus licheniformis encapsulated in alginate-chitosan nanoparticles (CNPs) beads supplemented with rice starch (RS) has been evaluated for its plant growth enhancement and disease control properties. The encapsulated Bacillus licheniformis was initially characterized for indole-3-acetic acid (IAA) production, nitrogen fixing capacity, 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase production and antifungal activity against Sclerotium rolfsii. In addition to this, the plant growth promoting and biocontrol properties of the encapsulated Bacillus licheniformis were also evaluated using Capsicum annuum (L.) (chilli) seedlings. From the results, the plants treated with encapsulated Bacillus licheniformis supplemented with CNPs were found to have maximum growth enhancement. At the same time, plants treated with encapsulated Bacillus licheniformis supplemented with CNPs and RS were found to have enhanced disease suppression. This revealed the application of encapsulated Bacillus licheniformis supplemented with CNPs and RS as a promising delivery system for agricultural applications.