AUTHOR=Vigentini Ileana , Fabrizio Vincenzo , Dellacà Federico , Rossi Sergio , Azario Isabella , Mondin Cristiano , Benaglia Maurizio , Foschino Roberto 

TITLE=Set-Up of Bacterial Cellulose Production From the Genus Komagataeibacter and Its Use in a Gluten-Free Bakery Product as a Case Study

JOURNAL=Frontiers in Microbiology

VOLUME=10

YEAR=2019

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2019.01953

DOI=10.3389/fmicb.2019.01953

ISSN=1664-302X

ABSTRACT=<p>The use of bacterial cellulose (BC) in food systems is still limited due to production costs. Nine clones belonging to <italic>Komagataeibacter hansenii</italic>, <italic>Komagataeibacter nataicola</italic>, <italic>Komagataeibacter rhaeticus</italic>, <italic>Komagataeibacter swingsii</italic>, and <italic>Komagataeibacter xylinus</italic> species were screened for cellulose productivity in growth tests with five different carbon sources and three nitrogen sources. The water-holding and rehydration capacities of the purified cellulose were determined. The structure of the polymer was investigated through nuclear magnetic resonance (NMR) spectroscopy, attenuated total reflection Fourier transform infrared (ATR-FT-IR) spectroscopy and X-ray diffraction (XRD) analysis, and observed by scanning electron microscope (SEM). Natural mutants of <italic>K. rhaeticus</italic> LMG 22126<sup>T</sup> and <italic>K. swingsii</italic> LMG 22125<sup>T</sup> showed different productivity. The factors “bacterial isolate” and “nitrogen source” significantly affected the production of cellulose (<italic>p</italic> &lt; 0.01) rather than the factor “carbon source” (<italic>p</italic> = 0.15). However, on average, the best conditions for increasing yield were found in medium containing glucose and peptone. Water-holding capacity (WHC) values ranged from 10.7 to 42.3 (<italic>g</italic><sub>water</sub>/<italic>g</italic><sub>cellulose</sub>) with significant differences among strains (<italic>p</italic> &lt; 0.01), while the rehydration capacity varied from 4.2 to 9.3 (<italic>g</italic><sub>water</sub>/<italic>g</italic><sub>cellulose</sub>). A high crystallinity (64–80%) was detected in all samples with Iα fractions corresponding to 67–93%. The ATR-FT-IR spectra and the XRD patterns confirmed the expected structure. BC made by GVP isolate of <italic>K. rhaeticus</italic> LMG 22126<sup>T</sup>, which was the strain with the highest yield, was added to a gluten-free bread formulation. Results obtained from measurements of technological parameters in dough leavening and baking trials were promising for implementation in potential novel foods.</p>