Spent mushroom substrate (SMS), a nutrient-dense byproduct of mushroom cultivation, has emerged as a promising feedstock for biochar production, offering a sustainable solution to modern agricultural and environmental challenges. This review explores SMS properties, its conversion into biochar, and its various applications. Due to its lignocellulosic structure, high organic matter (OM), and essential nutrients, SMS is ideal for pyrolysis, a process that enhances biochar’s porosity, nutrient retention, and carbon stability. These properties improve soil fertility, water retention, microbial activity, and plant growth while also contributing to climate change mitigation through carbon sequestration. SMS-derived biochar stands out for its superior benefits, including a balanced pH, a rich nutrient profile, and the ability to adsorb heavy metals, which mitigates soil and water contamination and minimizes toxic risks in the food chain. By enhancing soil structure, nutrient cycling, and moisture retention, SMS-derived biochar supports sustainable farming practices that reduce chemical fertilizer use and boost climate resilience. Beyond soil applications, SMS-derived biochar is effective in wastewater treatment, mitigating plant diseases, and improving mushroom cultivation substrates, thereby enhancing mycelial growth and productivity. Economically, it is a cost-effective alternative due to the abundant availability and inexpensive nature of SMS. Nevertheless, challenges still exist, particularly in optimizing production methods and ensuring consistency in biochar properties, influenced by variations in pyrolysis conditions and SMS types. Advances in production technology and sustainable practices are vital for scaling up SMS-derived biochar production. This paper emphasizes the transformative potential of SMS-derived biochar, advocating for its integration into circular economy frameworks and sustainable agricultural systems. Recommendations for future research and policy support are provided to maximize the ecological and economic benefits of SMS-derived biochar, fostering its widespread adoption in global agricultural and environmental strategies.

Fermented tea is traditionally consumed in many Asian countries. In Thailand, the product is made by anaerobic submerged fermentation of semi-mature tea leaves before being made into a ball form. This study aims to investigate the composition of health-associated bioactive compounds in fermented tea balls made from Camellia sinensis var. assamica, which is naturally grown in the forests of northern Thailand. The processing involves steaming semi-mature tea leaves followed by anaerobic fermentation in 2% NaCl solution (1:5 w/v of tea leaves solution). Levels of catechin (C), epicatechin (EC), epicatechin gallate (ECG), epigallocatechin gallate (EGCG), gallocatechin (GC), flavonols (myricetin, quercetin, and kaempferol), phenolic acids (caffeic acid, chlorogenic acid, coumaric acid, and sinapic acid), total phenolic content, and in vitro antioxidant activity were evaluated in fresh tea leaves, steamed tea leaves, and fermented tea leaves over a period of 60 days’ monitoring. The results indicated that fermented tea balls still contain significant amounts of tea polyphenols, although their processing may result in some loss of most bioactive compounds. The antioxidant activity measured by Ferric Reducing Antioxidant Power (FRAP), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and Oxygen Radical Absorbance Capacity (ORAC) assays also declined as the fermentation time was extended. However, phenolic acids, including caffeic acid and sinapic acid, contrastingly increased during prolonged fermentation by 74.35% and 171.43% from fresh leaves, respectively.

Pickled tea is an ethnic fermented product produced using Assam tea (Camellia sinensis var. assamica) leaves. It is produced in large quantities every year and the liquid waste from its production is estimated to be up to 2500 mL per every kilogram of pickled tea production. To reduce the waste, pickled tea juice remaining from the process was developed into (1) pineapple kombucha and (2) formulated functional drinks as “value added” products. The juice used for making kombucha was collected at 15 days of pickled tea fermentation due to its high value in antioxidant activity (previous study, 2250 µmol TE per g DW). After fermenting the juice with starter culture, the properties of pineapple kombucha were assessed at 0, 1, 3, 5, 7, 9, 11 days. Results showed that the total phenolic of pineapple kombucha was reduced, while antioxidant assay (FRAP and ORAC) slightly increased. The most suitable fermentation period of pineapple kombucha was at day 3. The formulated drink was made from mixing pineapple kombucha with ginger and lemon juice at various ratios including 100:0:0, 80:10:10 and 80:15:5. The ratio 80:10:10 gave the highest TP and antioxidant activity for the functional drink. In addition, for sensory analysis, liking attribute of 80:15:5 fermented juice kombucha pineapple favor was significantly higher compared to other formulations. The study demonstrates the promising second fermentation process of by-product juice from pickled tea production for the conversion to value-added functional drink with reasonable antioxidant properties.

ISHS III Asia Pacific Symposium on Postharvest Research, Education and Extension: APS2014 Changes in chemical composition, minerals, total phenolic compounds and antioxidant activities during germination of sunflower sprout

Ralstonia solanacearum, a pathogen causing bacterial wilt, threatens global crop production, necessitating sustainable biocontrol solutions. Bacillus amyloliquefaciens is a promising biocontrol agent, but the mechanisms of its interaction with R. solanacearum are not well understood. This study investigates the effects of R. solanacearum secretions on the growth, metabolite production, and antimicrobial properties of B. amyloliquefaciens BNC5. Untargeted metabolomics revealed increases in two known macrolactins (A and M), six novel macrolactins (BA1-6), and one novel polyketide (BAP1), along with decreases in 7-O-malonyl macrolactin A and a new macrolactin, BA7, following exposure to the secretions. Real-time polymerase chain reaction showed a downregulation of the tailoring enzyme gene bmmGT3. The reduced antimicrobial activity in the exposed extracts (78 vs 39-78 μg mL^-1 in unexposed extracts) is likely due to diminished macrolactin efficacy in macrolactin fractions from the exposed (512-1024 μg mL^-1) compared to those from the unexposed samples (4 μg mL^-1). Supported by tomato pot experiments, these results suggest that applying B. amyloliquefaciens extracts prior to introducing live bacteria may enhance the management of R. solanacearum in severely affected fields, providing a sustainable alternative to chemical pesticides.

This study verifies the influence of water regimes and potassium chlorate (KC1O 3 ) on photosynthetic rate, flower emergence and media moisture content of longan trees. The trees were grown in 150 liters lysimeter tanks filled with fine sand. The experimental design was a 2x2 factorial in completely randomized design (CRD) with 2 factors; 1) two levels of water regimes (well-watered and water deficit) and 2) two levels of KClO 3 at 10 and 0 g. The results revealed that the well-watered treatment produced faster days of terminal bud break than that of the water deficit treatment. The 10 g KClO 3 treatment induced 91 % flower emergence at 35 days after commencing the treatment, while the 0 g KClO 3 treatment had 82 % leaf flushing and had no flower emergence. Water deficit or KClO 3 treatments reduced the net carbondioxide (CO 2 ) exchange, transpiration and stomatal conductance rates. Moreover, the combination of well-watered and 0 g KClO 3 treatments gave the greatest values of the parameters. The well-watered treatment had higher volumetric water content in the growing medium and leaf water potential than the water deficit treatment, while for the 10 g and 0 g KClO 3 treatments had similar the media moisture content.