In this study, cellulose was obtained from sugarcane bagasse (SCB) and treated with xylanase to remove residual noncellulosic polymers (hemicellulose and lignin) to improve its dyeability. The cellulose fibers were dyed with natural dye solutions extracted from the heart wood of Ceasalpinia sappan Linn. and Artocarpus heterophyllus Lam. Fourier-transform infrared (FTIR) spectroscopy, Raman analysis, and whiteness index (WI) indicated successful extraction of cellulose by eliminating hemicellulose and lignin. The FTIR analysis of the dyed fibers confirmed successful interaction between natural dyes and cellulose fibers. The absorption (K) and scattering (S) coefficient (K/S) values of the dyed fibers increased in cellulose treated with xylanase before dyeing. Scanning electron microscopy (SEM) analysis showed that the surface of alkaline-bleached fibers (AB-fibers) was smoother than alkaline-bleached xylanase fibers (ABX-fibers), and the presence of dye particles on the surface of dyed fibers was confirmed by energy-dispersive spectrometry (EDS) analysis. The X-ray diffraction (XRD) revealed a higher crystallinity index (CrI), and thermal gravimetric analysis (TGA) also presented higher thermal stability in the dyed fibers with good colorfastness to light. Therefore, xylanase treatment and natural dyes can enhance dyeability and improve the properties of cellulose for various industrial applications.

Understanding the control of anthocyanin biosynthesis is beneficial to genetic improvement for floral production in Dendrobium orchids. Full-length cDNA of CHS, CHI1, CHI2, F3H, DFR, ANS, F3'5'H, and FLS was isolated from Dendrobium hybrids with purple, peach, white and greenish white flowers. Analysis of the deduced amino acid sequences and gene expression levels of the eight genes suggested potential causes of color variation among the hybrids. Peach hybrid (SC) was likely due to changes in anthocyanin production from cyanidin to pelargonidin through mutations in F3'H, and the low color intensity was likely derived from the low expression levels of CHI1 and CHI2. In addition, white hybrid (RW) was likely caused by several mutations in F3H and/or high expression levels of FLS, an enzyme that converts color flavonoid intermediates into colorless flavonols. Simultaneous loss of F3H, DFR, and ANS expression observed in another white hybrid (JW) indicated that an alteration of anthocyanin regulatory controls was likely the cause of white coloration. Furthermore, analysis of hybrid mutants bearing pale and dark flowers demonstrated the influence of the expression of anthocyanin genes on the intensity of flower colors. Data obtained from this work could contribute to new strategies for future orchid breeding.

Superoxide dismutase (SOD) is crucial antioxidant enzyme that plays a role in protecting cells against harmful reactive oxygen species (ROS) which are generated inside cells. Due to its functionality, SOD is used in many applications. In this study, Saccharomyces cerevisiae TBRC657 was selected as the SOD producer due to its high SOD production. After investigating an optimized medium, the major components were found to be molasses and yeast extract, which improved SOD production up to 3.97-fold compared to a synthetic medium. In addition, the optimized medium did not require any induction, which makes it suitable for applications in large-scale production. The SOD formulation was found to increase the stability of the conformational structure and prolong shelf-life. The results show that 1.0% (w/w) trehalose was the best additive, in giving the highest melting temperature by the DSF method and maintaining its activity at more than 80% after storage for 6 months. The obtained SOD was investigated for its cytotoxicity and ROS elimination against fibroblast cells. The results indicate that the SOD enhanced the proliferation and controlled ROS level inside the cells. Thus, the SOD obtained from S. cerevisiae TBRC657 cultured in the optimized medium could be a candidate for use as a ROS scavenger, which can be applied in many industries.