Bacterial cellulose nanofibrils were obtained from the floating pellicle developed at the air-liquid interface during Kombucha tea production. Kombucha-derived bacterial nanocellulose (KBNC) was purified by different treatments and characterized in terms of morphology, chemical structure, thermal decomposition pattern and crystallinity. 
 Purified KBNC was then employed in the production of poly(lactic acid) (PLA)-based composites obtained by melt compounding and compression molding. The morphology and the mechanical properties of the composites with increasing contents of KBNC (i.e. 1, 3, 5, 7 wt.%) were analyzed. Results showed that KBNC was suitable for the development of PLA composites with improved stiffness.