## 4 Conclusions  
The potential of grafting bacterial nanocellulose in yeast films functionalized with a mixture of cinnamon and lavender essential oil was evaluated in this study, as well as the influence of different concentrations of plasticizer, glycerol, and emulsifier, Tween 80, on mechanical properties, volatile fingerprint and the antimicrobial activity of films.  
Bacterial cellulose nanocrystals were obtained from Kombucha's SCOBY valorization, with dimensions ranging between 62 and 756 nm, with an average of 235 \(\pm\) 188 nm.  
Films based on yeast biomass with concentrations ranging 1.00-1.50% of glycerol as plasticizer and Tween as surfactant were obtained, functionalized with CLEO and bacterial nanocellulose, and further characterized. Grafted bacterial cellulose to yeast films were uniformly distributed in films, determined rougher films surfaces, with irregularities, indicated by SEM analysis. The grafted bacterial cellulose significantly increased the opacity of yeast films (\(p\) < 0.05) compared to the control samples but are still see-through. FT-IR spectra confirmed successful incorporation of bacterial cellulose in all three yeast films. Volatile fingerprint of CLEO mix indicated cinnamaldehyde as most abundant constituent of total VOC, almost 25% and iso-caryophyllene representing \(\sim\)15.5% of the volatiles, but also \(\alpha\)-Pinene, \(\alpha\)-Phellandrene, and Eugenol, which have antimicrobial activity. The VOCs from CLEO were identified in CNC yeast films, induced strong antimicrobial activity against spoilage microorganisms, as \(R\). _glutinis_, \(G\). _candidium_ and \(B\). _cereus_, but also significant antipathogen activity against \(L\). _monocytogenes_, \(S\). _aureus_, and \(E\). _coli_.  
Yeast films with 1.50% glycerol and 1.50% Tween 80 are more flexible and bacterial nanocellulose grafted into yeast film increases elastic modulus compared to the control samples without CNC.  
The development and characterization of an innovative, sustainable packaging solution based on yeast biomass, functionalized with cinnamon and lavender essential oil mix and bacterial cellulose obtained from SCOBY indicated that it could be further optimized to fit different food applications as active packaging.  
Conceptualization, I.B. and D.B.; methodology, I.B., L.G.-G., A.C.C., F.S. and D.B.; software, D.B.; validation, D.B. and I.B.; formal analysis, I.B.; investigation A.C.C. and L.G.-G.; resources, I.B.; data curation, I.B.; writing--original draft preparation, I.B.; writing--review and editing, I.B. and D.B.; visualization, A.C.C. and I.B.; supervision, D.B., F.S. and C.F.; project administration, I.B.; funding acquisition, I.B. All authors have read and agreed to the published version of the manuscript.  
This research was funded by grant number RF 2486/31.05.2024 from Dunarea de Jos University of Galati, Romania.  
Not applicable.  
The original contributions presented in this study are included in the article. Further inquiries can be directed to the corresponding author.  
Center MoRAS developed through Grant POSCCE ID 1815, cod SMIS 48,745 10.10.2024, (www.moras.ugal.ro).  
The authors declare no conflicts of interest.