Green synthesis and biological evaluation of glaucanic acid and dihydrocompactin acid by endophytic fungus Penicillium polonicum from Zingiber officinale.

Fungal endophytes are valued for biosynthesizing chemically diverse metabolic cascade with interesting biological activities. In the current investigation, two compounds were isolated from Penicillium polonicum, an endophyte of Zingiber officinale. The active moieties, glaucanic acid (1) and dihydrocompactin acid (2) were isolated from the ethyl acetate extract of P. polonicum and characterized by NMR and mass spectroscopy. Further, bioactive potential of the isolated compounds was evaluated by antimicrobial, antioxidant and cytotoxicity assays. Compounds 1 and 2 displayed antifungal activity against phytopathogen Colletotrichum gloeosporioides with more than 50% reduction in its growth. Both the compounds exhibited antioxidant activity against free radicals (DPPH and ABTS) and cytotoxicity activity against cancer cell lines respectively. The compounds, glaucanic acid and dihydrocompactin acid are being reported for the first time from an endophytic fungus. This is the first report on the biological activities of Dihydrocompactin acid produced by endophytic fungal strain.

Fungal endophyte bioinoculants as a green alternative towards sustainable agriculture.

Over the past half century, limited use of synthetic fertilizers, pesticides, and conservation of the environment and natural resources have become the interdependent goals of sustainable agriculture. These practices support agriculture sustainability with less environmental and climatic impacts. Therefore, there is an upsurge in the need to introduce compatible booster methods for maximizing net production. The best straightforward strategy is to explore and utilize plant-associated beneficial microorganisms and their products. Bioinoculants are bioformulations consisting of selected microbial strains on a suitable carrier used in the enhancement of crop production. Fungal endophytes used as bioinoculants confer various benefits to the host, such as protection against pathogens by eliciting immune response, mineralization of essential nutrients, and promoting plant growth. Besides, they also produce various bioactive metabolites, phytohormones, and volatile organic compounds. To design various bioformulations, transdisciplinary approaches like genomics, transcriptomics, metabolomics, proteomics, and microbiome modulation strategies like gene editing and metabolic reconstruction have been explored. These studies will refine the existing knowledge on the diversity, phylogeny and beneficial traits of the microbes. This will also help in synthesizing microbial consortia by evaluating the role of structural and functional elements of communities in a controlled manner. The present review summarizes the beneficial aspects associated with fungal endophytes for capitalizing agricultural outputs, enlists various multi-omics techniques for understanding and modulating the mechanism involved in endophytism and the generation of new bioformulations for providing novel solutions for the enhancement of crop production.

Endophytic Fungi-Mediated Biocatalysis and Biotransformations Paving the Way Toward Green Chemistry.

Catalysis is a process carried out in the presence of a heterogenous catalyst for accelerating the rate of a chemical reaction. It plays a pivotal role in transition from take, make, and dispose technology to sustainable technology via chemo- and biocatalytic processes. However, chemocatalyzed reactions are usually associated with copious amounts of perilous/hazardous environmental footprints. Therefore, whole-cell biotransformations or enzyme cocktails serve as cleaner biocatalytic alternatives in replacing the classical chemical procedures. These benchmark bioconversion reactions serve as important key technology in achieving the goals of green chemistry by eliminating waste generation at source. For this, nature has always been a driving force in fuelling natural product discovery and related applications. The fungal endophytic community, in particular, has undergone co-evolution with their host plant and has emerged as a powerful tool of genetic diversity. They can serve as a treasure trove of biocatalysts, catalyzing organic transformations of a wide range of substances into enantiopure compounds with biotechnological relevance. Additionally, the biocatalytic potential of endophytic fungi as whole-intact organisms/isolated enzyme systems has been greatly expanded beyond the existing boundaries with the advancement in high-throughput screening, molecular biology techniques, metabolic engineering, and protein engineering. Therefore, the present review illustrates the promising applications of endophytic fungi as biocatalysts for the synthesis of new structural analogs and pharmaceutical intermediates and refinement of existing proteins for novel chemistries.

Engineering Host Microbiome for Crop Improvement and Sustainable Agriculture.

Dynamic consortium of microbial communities (bacteria, fungi, protists, viruses, and nematodes) colonizing multiple tissue types and coevolving conclusively with the host plant is designated as a plant microbiome. The interplay between plant and its microbial mutualists supports several agronomic functions, establishing its crucial role in plant beneficial activities. Deeper functional and mechanistic understanding of plant-microbial ecosystems will render many "ecosystem services" by emulating symbiotic interactions between plants, soil, and microbes for enhanced productivity and sustainability. Therefore, microbiome engineering represents an emerging biotechnological tool to directly add, remove, or modify properties of microbial communities for higher specificity and efficacy. The main goal of microbiome engineering is enhancement of plant functions such as biotic/abiotic stresses, plant fitness and productivities, etc. Various ecological-, biochemical-, and molecular-based approaches have come up as a new paradigm for disentangling many microbiome-based agromanagement hurdles. Furthermore, multidisciplinary approaches provide a predictive framework in achieving a reliable and sustainably engineered plant-microbiome for stress physiology, nutrient recycling, and high-yielding disease-resistant genotypes.