Agroindustrial wastes represent a rich and underutilized source of valuable minerals. Because the amount of biomass wastes generated by the agroindustry is increasing and the demand for sustainability is arising, there is a growing need for improving agroindustrial waste utilization and valorization. One of the major industrial interests has been obtaining silica from biomass wastes. The synthesis of silica from agroindustrial waste materials typically involves the use of high energy input for calcination or incineration and chemicals for extraction. To reduce energy consumption and chemical waste generation, we modified a sol-gel method to yield a by-product that can be used as a fertilizer. High purity silica was obtained from rice husk (95.1%), rice straw (91.4%), and corncob (95.9%). The silica particles were amorphous and white in color. The mean diameters of the silica particles obtained from rice husk, rice straw, and corncob were 72.4, 68.1, and 52.9 µm, respectively. The acid waste generated from the process was neutralized to yield potassium chloride. This by-product had mineral contents that could be used for inorganic fertilizer. In addition to supporting sustainability, the development of agroindustrial waste utilization methods is important for the establishment of inexpensive processes that are adaptable for large-scale manufacturing.

Herbal plants are frequently used for medication by people as they contain rich bioactive compounds. Turmeric (Curcuma longa) and bitter ginger (Zingiber zerumbet) are types of rhizome herbal plants with the highest amount of production in Indonesia. They contain bioactive compounds applicable for antibiotics against resistant bacteria, one of which is MRSA (Methicillin-resistant Staphylococcus aureus). This study aims to investigate the compound components in turmeric and bitter ginger, which might be anti-MRSA candidates against the PBP2a binding side by in-silico analysis. A total of 24 ligands of turmeric and bitter ginger are bound to the target protein, the PBP2a receptor. The binding results are followed with a test of biological activity, physicochemical properties, and toxicity of the herbal plant compounds. The study resulted in 12 ligands potentially being anti-MRSA with binding on the allosteric side of PBP2a. In sum, it suggested three compounds with the best potential for anti-MRSA candidates: curcumin, germacrone, and zerumbone and may be considered as drug candidates for therapeutic aims in several human infections associated with MRSA. Nevertheless, in vitro and in vivo confirmations are needed.