Therapeutic selectivity is a critical issue in cancer therapy. As a result of its adjustable physicochemical characteristics, the Au/cellulose nanocomposite currently holds a lot of potential for solving this challenge. This work was designed to prepare a Au/cellulose nanocomposite with enhanced anticancer activity through the regulation of the mitogen-activated protein kinases (MAPK) signaling pathway. Nanocellulose, nanogold (AuNPs), and a Au/cellulose nanocomposite were biosynthesized from microgreen alga Chlorella vulgaris. Using UV-Vis absorption spectroscopy, transmission electron microscope (TEM), zeta potential analyzer, and Fourier transform infrared spectroscopy (FTIR), the synthesized nanoparticles were confirmed and characterized. In human alveolar basal epithelial cells (A549 cells), the selectivity and anticancer activity of the produced nanoparticles were evaluated. The cytotoxicity results revealed that the inhibitory concentration (IC50) of the Au/cellulose nanocomposite against A549 cancer lung cells was 4.67 ± 0.17 µg/µL compared to 182.75 ± 6.45 µg/µL in the case of HEL299 normal lung fibroblasts. It was found that treatment with nanocellulose and the Au/cellulose nanocomposite significantly increased (p < 0.05) the relative expression of tumor suppressor 53 (p53) in comparison to control cells. They also significantly (p < 0.05) decreased the relative expression of the Raf-1 gene. These findings indicate that nanocellulose and the Au/cellulose nanocomposite regulate cell cycles mostly via the motivation of p53 gene expression and reduction of Raf-1 gene expression.

The present work studied the optimization of aeration rate, agitation rate and oxygen transfer and the use of various batch fermentation strategies for xylanase production from a recombinant Aspergillus nidulans strain in a 3 L stirred tank reactor. Maximum xylanase production of 1250 U/mL with productivity of 313 U/mL/day was obtained under an aeration rate of 2 vvm and an agitation rate of 400 rpm using batch fermentation. The optimum volumetric oxygen transfer coefficient (k_La) for efficient xylanase production was found to be 38.6 h^-1. Fed batch mode and repeated batch fermentation was also performed with k_La was 38.6 h^-1. Xylanase enzyme productivity increased to 327 with fed batch fermentation and 373 U/mL/day with repeated batch fermentation. Also, maximum xylanase activity increased to 1410 U/mL with fed batch fermentation and 1572 U/mL with repeated batch fermentation.