Co-Cultivation of Komagataeibacter xylinus MS2530 with Various Yeast Strains: Production and characterization of bacterial cellulose Films

• A new strain producing BK was obtained • Fermentation time was significantly reduced from 14 to 5-7 days. • Brewery industry waste was used as an alternative economical medium. • Co-culturing resulted in increased BC yield (20.9g/L in HS and 26.4g/L in BSY). High production costs and low yield of bacterial cellulose (BC) remain major impediments to the large-scale industrial production of BC. Therefore, the cost reduction through utilization of inexpensive cultivation media, such as recycled industrial waste, and identification of highly efficient cellulose-producing bacterial strains are very important in this context. The present study aims to explore ways to increase the yield of bacterial cellulose by selecting a more effective strain-producer of Komagataeibacter xylinus and employing a co-cultivation approach using various yeast strains, as well as by utilizing brewery waste as an alternative, cost-effective medium for cultivation. Scanning electron microscopy and Fourier transform infrared spectroscopy were used to evaluate the differences in the structure of BC films obtained by K. xylinus cultivated alone and with yeast strains. Both classical Hestrin-Schramm (HS) and Residual brewer's yeast (BSY) media were used. Our study showed that the employment of residual brewer's yeast and co-cultivation approaches resulted in a significant increase in bacterial cellulose yield and reduction of fermentation time. Thus, replacing the HS medium to residual brewer's yeast may substantially decrease large-scale BC production costs and reduce environmental pollution by utilization of the industrial waste.