This study introduces biodegradable nursery bags using poly(lactic acid) (PLA), a widely used biodegradable polymer, and spent coffee grounds (SCGs), a byproduct of the brewing process in the coffee industry. SCGs were oil-extracted to produce extracted spent coffee grounds (exSCGs), which were characterized by their physical properties, chemical functionality, and thermal behavior. The exSCGs were blended with PLA at loadings of 5, 10, and 15 wt%. Analysis showed that exSCGs retained 3-5 wt% residual coffee oil, exhibiting a lower surface area (1.1163 m(2)/g) compared to SCGs (1.5010 m(2)/g), along with a higher pore volume (1.148 x 10(-3) cm(3)/g) and pore size (similar to 410 nm). All PLA/exSCG bio-composite films displayed a light brown color, well-dispersed exSCG particles, and excellent UV light barrier properties, with transmittance reduced to 1-2%. The residual coffee oil acted as a plasticizer, reducing the glass transition temperature, melting temperature, and crystallinity with increasing exSCG content. Mechanical testing revealed enhanced flexibility compared to neat PLA. Soil burial tests showed increased biodegradability with higher exSCG content, supported by SEM analysis revealing cracks around exSCG particles. The PLA/exSCG blend containing 10 wt% exSCGs exhibited optimal performance, with a significant increase in melt flow index (from 4.22 to 8.17 g/10 min) and approximately double the melt strength of neat PLA, balancing processability and mechanical properties. This innovation provides a sustainable alternative to plastic nursery bags, addressing waste valorization and promoting eco-friendly material development for agricultural applications.

Modified clay granules were used to promote Azotobacter vinelandii cell adhesion. The A. vinelandii cells in the clay granules were used as a biofertilizer and a plant material. The production process was carried out under variable temperatures. The raw ingredients consisted of clay, sawdust waste, and spent coffee grounds in different ratios. Scanning electron microscopy (SEM) was used to analyze the microstructure. The results of the study showed the addition of sawdust waste and spent coffee grounds had increased the water absorption of the fired clay granules based on their porosity. However, increasing the firing temperature in the range of 900 degrees C- 1100 degrees C decreased the water absorption and porosity and increased the bulk density of the fired clay granules. A. vinelandii was enriched to be used as a cell suspension. The fired clay granules were immersed in a cell suspension to immobilize the A. vinelandii cells for 48 h. The SEM-based investigations indicated that the fired clay granules were suitable for containing A. vinelandii cells. The results demonstrated high viability of bacterial cells fixed in the fired clay granules at 2.7x 10(7) CFU/g. Furthermore, the test results of bacterial cells in the fired clay granules for marigold planting media revealed that it had effectively encouraged plant growth. The nitrogen-fixing bacterial cells in the clay granules obtained from this research were determined to be appropriate for use as an ecological soil replacement in the future.