Cellulose produced by Gluconacetobacter xylinus strains ATCC 53524 and ATCC 23768: Pellicle formation, post-synthesis aggregation and fiber density.
The pellicle formation, crystallinity, and bundling of cellulose microfibrils produced by bacterium Gluconacetobacter xylinus were studied. Cellulose pellicles were produced by two strains (ATCC 53524 and ATCC 23769) for 1 and 7 days; pellicles were analyzed with scanning electron microscopy (SEM), X-ray diffraction (XRD), vibrational sum-frequency-generation (SFG) spectroscopy, and attenuated total reflectance infrared (ATR-IR) spectroscopy. The bacterial cell population was higher at the surface exposed to air, indicating that the newly synthesized cellulose is deposited at the top of the pellicle. XRD, ATR-IR, and SFG analyses found no significant changes in the cellulose crystallinity, crystal size or polymorphic distribution with the culture time. However, SEM and SFG analyses revealed cellulose macrofibrils produced for 7 days had a higher packing density at the top of the pellicle, compared to the bottom. These findings suggest that the physical properties of cellulose microfibrils are different locally within the bacterial pellicles.
Department of Chemical Engineering and Materials Research Institute, The Pennsylvania State University, University Park, PA 16802, USA. Electronic address: cml5481@psu.edu.
Christopher M
CM
Lee
Intercollege Graduate Degree Program in Plant Biology, The Pennsylvania State University, University Park, PA 16802, USA. Electronic address: gujin.pku@gmail.com.
Jin
J
Gu
Department of Chemical Engineering and Materials Research Institute, The Pennsylvania State University, University Park, PA 16802, USA. Electronic address: kuk188@psu.edu.
Kabindra
K
Kafle
Intercollege Graduate Degree Program in Plant Biology, The Pennsylvania State University, University Park, PA 16802, USA; Department of Agricultural and Biological Engineering, The Pennsylvania State University, University Park, PA 16802, USA. Electronic address: JCatchmark@engr.psu.edu.
Jeffrey
J
Catchmark
Department of Chemical Engineering and Materials Research Institute, The Pennsylvania State University, University Park, PA 16802, USA. Electronic address: shkim@engr.psu.edu.
Seong H
SH
Kim
D002482:Cellulose / Q000096:biosynthesis* / Q000737:chemistry*; D041822:Gluconacetobacter xylinus / Q000166:cytology / Q000378:metabolism*; D055595:Mechanical Phenomena
D002482:Cellulose
Bacterial cellulose; Cellulose microfibril aggregation; Fiber density