Bacterial cellulose is a biomaterial known for its physical and mechanical properties, including its high mechanical strength, water retention capacity, and biocompatibility. Its production from various carbohydrates has been widely studied, aiming to find more efficient and cost-effective culture media. This study investigated the production of bacterial cellulose from agroindustrial asparagus peel waste by Komagataeibacter rhaeticus QK23. A strain of QK23 was isolated and cultivated from a kombucha tea, identified based on morphological and molecular characteristics using the 16S rRNA gene. The waste was hydrolyzed and converted into fermentable sugars. Using the response surface methodology, the inoculum dose (1–20%) and incubation time (3–25 days) were evaluated concerning bacterial cellulose yield. The results demonstrated that with an optimal inoculum dose of 10.5% and an incubation time of 25 days, a production of 2.57 g/L was achieved. It was characterized as similar to type I cellulose, exhibiting a high degree of crystallinity (81.89%) and suitable morphological properties, evidenced by a fiber size of 178 nm and a surface roughness of 27.05 nm. Converting asparagus waste into bacterial cellulose is a sustainable and effective strategy that promotes the development of advanced biomaterials in biotechnology research.

Mn₃O₄ nanoparticles have been synthesized using alcoholic extracts, at pH = 7 and low temperature (60 °C), from different masses (1.00, 3.00, 5.00, and 7.00 g) of fresh leaves from Nerium oleander and Bixa orellana, without additional heat treatment. Appropriate techniques were used to identify the secondary metabolites of the extracts and evaluate the structural, optical, and chemical properties of the nanoparticles. The XRD results confirmed the formation of Mn₃O₄ nanoparticles with crystallite size in the 5−8 nm range, with more notable effects on the crystallinity of the nanoparticles obtained with B. orellana extracts. The greatest effect on the bandgap was observed in nanoparticles synthesized with N. oleander extracts. Raman spectra confirmed phonon confinement, and in the PL spectra, emission bands associated with structural defects, such as oxygen vacancies, were observed. In FTIR spectra, the main bands of Mn₃O₄ were identified, whose intensity decreased as the concentration of extract and other bands associated with functional groups of the extract increased. TEM images showed nanoparticles were spherical with 7.81 nm (N1) and 7.94 nm (B1) average diameters. The extract from N. oleander leaves was more appropriate than that from B. orellana for the synthesis of Mn₃O₄ nanoparticles under the conditions used.