Enzymatic Modification of Flaxseed Fibers

Abstract

Flaxseed (Linum usitatissimum L.) fibers were modified by oxidoreductive and cellulolytic enzymes. The lignin amount and intrinsic plant peroxidase activity was evaluated by histochemical and spectrophotometric assays. Peroxidase activity was not found from bast fibers. The flaxseed fibers were further separated and treated with laccase to conjugate the model compounds, that is, the hydrophobic gallate molecules on fiber surfaces. Laccase was able to slowly oxidize fiber-conjugated phenolics, but no fundamental changes in fiber cell surface structure or notable coupling of the applied hydrophobic gallate molecules onto the fibers occurred, as revealed by Fourier transform infrared spectroscopy. The reactivity of the mature fibers was further investigated using cellulolytic enzymes. Cellobiohydrolase (CBH) and endoglucanase (EG)-rich enzyme preparations were applied to reach a hydrolysis degree of 1-6% (of the fiber dry matter) using a standard enzyme dosage. The CBH mixture altered the fiber surface morphology distinctly, and SEM images illustrated fibers in which the cellulose fibrils seemed to be loosened and partially hydrolyzed. In contrast, the effect of the EG-rich preparation without CBH activity was notable on the fiber surface, polishing the surfaces. The cellulolytic treatments were potentially interesting for specific enzymatic modifications of flax fiber surfaces, whereas the approach to use oxidoreductive enzyme treatments on mature linseed fibers offered little potential, obviously due to the low lignin content of the fibers.

Histological examinations of the in vivo biocompatibility of oxycellulose implanted into rat skeletal muscle

“…[7][8][9] A problem with the use of plant fibers is the fact that they are not biodegradable and cannot be absorbed, since the main component of the fibers is the natural polymer cellulose. 30 This problem can be circumvented by oxidizing the cellulose.…”

Bone Regeneration after Treatment with Covering Materials Composed of Flax Fibers and Biodegradable Plastics: A Histological Study in Rats

“…This might be attributed, on the one hand, to very low content of flax fibers in the composite (only 20%) and thereby a small proportion of PHB and, on the other hand, to shielding of fibers by embedding in a polymer matrix and to the very slow degradation of used polymers. A further exacerbating factor is that cellulose, main component of flax, is not metabolized and degraded in the body [81, 82]. Therefore, these flax covering materials in presented form are not clinically applicable.…”

Fabrication and mechanical properties of flaxseed fiber bundle-reinforced polybutylene succinate composites

“…Alkali treatment has been simplest traditional method for cellulosic fibers to remove impurities [18], but fiber quality depended upon the alkali concentration, temperature and time [17,19]; however, decrease in the surface impurities resulted in better mechanical properties [20]. The enzymatic methods for retting and surface modification of flaxseed straws reported limitations in parameters and processability [21]. Lamb et al [22] carried out flaxseed fiber individualization using mechanical separation and chemo-mechanical combined treatments, which resulted in very short, non-spinnable and damaged flaxseed fibers, indicating higher alkali concentration significantly increased fiber damage and weight loss.…”

“…Alkali treatment has been simplest traditional method for cellulosic fibers to remove impurities [18], but fiber quality depended upon the alkali concentration, temperature and time [17,19]; however, decrease in the surface impurities resulted in better mechanical properties [20]. The enzymatic methods for retting and surface modification of flaxseed straws reported limitations in parameters and processability [21]. Lamb et al.…”