Bacterial cellulose biosynthesis: Optimization strategy using iranian nabat industry waste

Bacterial cellulose (BC) is a biopolymer has found extensive applications across different fields due to its nanostructure and biomaterial performance. This study focused on optimizing yield of BC produced by <i>Komagataeibacter xylinus</i> CH1, isolated from kombucha SCOBY. The study aimed to use Nabat industry waste (NIW) as a cost-effective alternative carbon source for submerged fermentation. To optimize the fermentation criteria, the central composite design was used with the inoculation amount (1.5-4.5 % VV^-1), NIW (0-1%), and fermentation time (3-7 days) as independent variables. The impressive results indicated the yield was enhanced up to 45.543 gL^-1 at 3.013 % VV^-1 of inoculation, 0.516 % NIW, and 7 days of stirred fermentation. SEM, XRD, FTIR, and TGA were applied to evaluate the characteristics of freeze-dried BC, such as the three-dimensional, porous structure, crystalline peaks, amorphous haloes, and thermal stability. The physicochemical properties of BC including high moisture content (93.022 ± 0.472 %), water absorption rate (569.473 ± 3.739 %), water-holding capacity (1333.016 ± 3.680 %), porosity (166.247 ± 2.055 %), and low water activity (0.296 ± 0.030 %) were achieved. Rheological properties of BC suspensions showed that G' dominated over G″, with tan <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mi>δ</mml:mi></mml:mrow> </mml:math> values lower than 1. These characteristics indicate NIW and stirred fermentation conditions are a promising method for producing BC in high yield.