Influence of the carbon source on the properties of poly-(3)-hydroxybutyrate produced by Paraburkholderia xenovorans LB400 and its electrospun fibers.

Poly-3-hydroxybutyrate (PHB) is a biocompatible polymer produced by a wide variety of bacteria from different carbon sources. However, the carbon source effects on PHB properties are largely unknown. This study aimed to characterize PHB produced by Paraburkholderia xenovorans LB400 supplied with glucose (PHBg), mannitol (PHBm), or xylose (PHBx) as sole carbon sources and to evaluate their potential application as the main component of scaffolds obtained by electrospinning. The PHBs produced by strain LB400 had different molecular weights; the largest value corresponded to PHBm. The XRD-spectra revealed that PHB produced by strain LB400 from the three carbon sources are less crystalline than the commercially available polymer (PHBc). Moreover, the electrospinning process decreases even further their degree of crystallinity, which could lead to an improvement in the mechanical properties of the polymers. Relevantly, PHBx-microfibers exhibited mechanical characteristics similar to those of human skin. None of the scaffolds made of PHBs from strain LB400 grown in different carbon sources showed adverse effects on fibroblast cell growth. Thus, modifying the sugar used as the carbon source may be useful to tune the structural properties of PHB and its performance as a component of electrospun scaffolds, which may better fit specific biomedical applications.