Background: Ethidium bromide is a common reagent that is used in nucleic acid staining. However, ethidium bromide has toxic and carcinogenic properties that are harmful to the environment. Phenanthrene dioxygenase (encoded by phdA, phdB, phdC, and phdD genes) in Nocardioides sp. KP7 can oxidize the phenanthridine structure aim to eliminate carcinogenic properties. Objective: This study aims to visualize and predict the structure, active site, and characteristics of the phenanthrene dioxygenase using bioinformatics tools. Methods: Plasmid design were prepared by inserting genes of interest phdA, phdB, phdC, and phdD from the NCBI database. Furthermore, several protein analysis tools were used for structure visualization, active site enzyme improvement, and protein characteristic of phenanthrene dioxygenase. Results: The prediction results found that phenanthrene dioxygenase reacts with the ethidium bromide substrate through the interaction of Fe3+ ions with water. The solubility level of phenanthrene dioxygenase protein is 0.404, suggesting that the protein has low solubility. The protein isoelectric point (pI) is between 5.17 to 5.36, and the protein molecular weight is 121.143 kDa. Conclusion: In silico analysis has supported that recombinant plasmid met characteristics for the construct which consists of gene interest and protein library.

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.