Institute of Himalayan Bioresource Technology

Shiitake [Lentinula edodes (Berk)] is one of the most widely cultivated edible mushrooms worldwide, valued for its distinct flavour, nutritional richness, and therapeutic potential. Despite its long-standing culinary and medicinal use, existing literature addresses its various attributes in isolation, focusing either on cultivation methods, nutraceutical properties, or post-harvest processing. This comprehensive review aims to provide a detailed overview of shiitake mushroom biology, combining recent cultivation techniques, substrate-based nutritional modulation, bioactive compound profiling, and sustainable applications of spent shiitake substrate (SSS). Beginning with details on traditional and modern cultivation approaches, including log-based and sawdust-based synthetic methods, the review highlights how substrate type influences yield and nutrient content. The review further compiles major bioactive compounds and their preclinical evidence suggests roles in immunity, anticancer potential, metabolic health, and vitamin D supplementation. Importantly, this work highlights the emerging role of SSS in circular bioeconomy models, including its use in agriculture, bioremediation, and energy recovery. This review addresses a significant gap in existing literature by connecting traditional knowledge with contemporary research, emphasizing shiitake as both a gourmet and medicinal fungus. Additionally, it highlights shiitake as a sustainable biotechnological resource with applications in food, health, and environmental sectors.

Plant viruses and microbiomes are pivotal to plant health, growth, and their ability to withstand environmental challenges. However, the extent to which viruses engage in direct or indirect crosstalk with plant-associated microbial communities remains largely unexplored. Traditionally, plant viruses are considered as harmful agents that disrupt normal plant functions, but new research indicates they may also engage in complex interactions with the plant's microbiome. On the other hand, the plant microbiome, comprising a diverse assembly of bacteria, fungi, and other microbes, can influence the plant's responses to viral infections, potentially altering the course of the disease. Thus, we emphasize the intricate interplay between plant viruses and microbiomes, particularly how viruses might "communicate" with microbial communities to alter the host environment or bypass immune defenses. The mechanisms driving these interactions, such as virus-induced shifts in plant metabolism, signaling pathways, and immune responses that indirectly affect microbiome composition are also discussed. The beneficial effect of plant-associated microbial communities against viral infections and the strategy of microbiome-based approaches for managing viral diseases are also focused. By moving beyond the traditional view of pathogen-host interactions, this review will highlight the importance of considering the three-way relationship among plants, viruses, and microbiomes to advance our understanding of plant health and foster innovative solutions for sustainable agriculture.

Calendula ( Calendula officinalis L.), commonly known as pot marigold, is a globally valued flower recognized for its ornamental appeal, edibility, and diverse bioactive properties. In the present study, the effects of foliar application of salicylic acid (SA) at different concentrations (50–200 mg/L) were evaluated under greenhouse conditions. The effect on various vegetative and floral growth parameters, along with their effect on phytochemical content, antioxidant activity, antimicrobial activity, and α ‐amylase inhibition activity of the flowers, was evaluated. The results showed that foliar spray of SA at a concentration of 100 mg/L was most effective for vegetative and floral growth, leading to improved plant height, leaf area, plant spread, flower weight, and flower size in comparison to the control. The 200 mg/L SA treatment resulted in the highest levels of total phenolics, flavonoids, and carotenoids, as well as the highest antioxidant capacities (DPPH and ABTS + assays). The α ‐amylase inhibition and antimicrobial activities were observed to increase at higher concentrations of foliar spray of SA. The HPLC analysis of phenolic compounds revealed that rutin was the predominant phenolic compound in calendula flowers, with the highest concentration of 1064.65 µg/100 mg recorded for treatment T 3 (150 mg/L SA). This investigation underscores the efficacy of salicylic acid foliar application as a viable approach to improve agronomic performance and nutraceutical quality in calendula, presenting significant implications for its application in functional food, pharmaceutical, and ornamental sectors.

Lignin is a heteropolymer component of ligno-cellulosic biomass made up of monomers connected together by various linkages, the most common of which is the β-O-4 bond. As previously demonstrated, lytic polysaccharide monooxygenase (LPMO) can catalyse the oxidative cleavage of β-O-4 linkage of lignin model compound guaiacyl glycerol-β guaiacyl ether (GGE). But the enhancement of enzymatic activity and stability remains a critical challenge for biocatalytic lignin valorization. In this study, an LPMO-cobalt phosphate organic-inorganic hybrid nanoflower (Co@LPMO-HNF) was developed as a robust biocatalyst for the cleavage of β-O-4 bond. The Co@LPMO-HNF was biochemically and morphologically characterized. Co@LPMO-HNF displayed an optimum temperature of 100°C and pH 8, exhibiting 1.65-fold higher activity than free LPMO. The Michaelis-Menten kinetic parameters indicated that the Co@LPMO-HNF had 20 fold higher Vmax and 13 fold higher turnover number (kcat) as compared to free LPMO for GGE. The catalytic efficiency (kcat/Km) of Co@LPMO-HNF was found to be 700 M- 1s- 1which was significantly comparable to free LPMO (650 M- 1s- 1). Notably, Co@LPMO-HNF achieved 97% GGE conversion within 24h versus 40% for the free enzyme and retained 52% of its activity after four catalytic cycles. This is first study to report the synthesis of LPMO based cobalt phosphate nanoflowers (Co@LPMO-HNF) with enhanced activity and stability for the oxidative cleavage of lignin derived compounds. Thus, LPMO loaded hybrid nanoflowers could be of great potential for the sustainable oxidation of lignin and its model compounds.