Hydrating softwood and hardwood samples using pure and modified supercritical carbon dioxide

This article describes an in-progress research project that looks to investigate the use of supercritical carbon dioxide (scCO2) for the addition of water to historic and modern, softwood and hardwood samples. The experiments were carried out at 20 MPa and 50 °C, the effects of co-solvent addition, methanol (MeOH), were examined. A three point bend test provided mechanical data for the wood samples treated with both pure and modified scCO2. All the wood samples, with only one exception, saw an increase in Modulus of Rupture (MOR) after being treated with scCO2. Thereby indicating an increased resistance to force in the treated samples. Diffuse Reflectance Infrared Fourier Transform (DRIFT) spectroscopy was performed to help deduce if any trends in the OH/CH and OH/Cellulose peak area ratios could be established with the nature of the treatment and the type of wood used. The development of this technique seeks to be relevant and safe for applications within modern conservation practices, where dry and fragile materials are prevalent

Anti-proliferative effect of Rosmarinus officinalis L. extract on human melanoma A375 cells

Rosemary (Rosmarinus officinalis L.) has been used since ancient times in traditional medicine, while nowadays various rosemary formulations are increasingly exploited by alternative medicine to cure or prevent a wide range of health disorders. Rosemary's bioproperties have prompted scientific investigation, which allowed us to ascertain antioxidant, anti-inflammatory, cytostatic, and cytotoxic activities of crude extracts or of pure components. Although there is a growing body of experimental work, information about rosemary's anticancer properties, such as chemoprotective or anti-proliferative effects on cancer cells, is very poor, especially concerning the mechanism of action. Melanoma is a skin tumor whose diffusion is rapidly increasing in the world and whose malignancy is reinforced by its high resistance to cytotoxic agents; hence the availability of new cytotoxic drugs would be very helpful to improve melanoma prognosis. Here we report on the effect of a rosemary hydroalcoholic extract on the viability of the human melanoma A375 cell line. Main components of rosemary extract were identified by liquid chromatography coupled to tandem mass spectrometry (LC/ESI-MS/MS) and the effect of the crude extract or of pure components on the proliferation of cancer cells was tested by MTT and Trypan blue assays. The effect on cell cycle was investigated by using flow cytometry, and the alteration of the cellular redox state was evaluated by intracellular ROS levels and protein carbonylation analysis. Furthermore, in order to get information about the molecular mechanisms of cytotoxicity, a comparative proteomic investigation was performed

Synthesis of alginate-silica hybrid hydrogel for biocatalytic conversion by ß-glucosidase in microreactor

The organic–inorganic hybrid materials have been used in different fields to immobilize biomolecules since they offer many advantages. The aim of this study was to optimize and characterize the alginate-silica hybrid hydrogel as a stable and injectable form for microfluidic systems using internal gelation method and increase the stability and activity of immobilized enzyme for biocatalytic conversions as well. Characterization was carried out by scanning electron microscopy, energy dispersive spectroscopy/mapping, Brunauer–Emmett–Teller, Barrett–Joyner–Halenda, and Fourier-transform infrared spectroscopy analyses, and the shrinkages of monoliths were evaluated. Subsequent to optimizing the enzyme concentration (40 µg), hydrolytic conversion of 4-nitrophenyl ß-d-glucopyranoside (pNPG) was performed to understand the behavior of the bioconversion in the microfluidic system. The yield was 94% which reached the equilibrium at 24 h indicating that the alginate-silica gel derived microsystem overcome some drawbacks of monolithic systems. Additionally, bioconversion of Ruscus aculeatus saponins was carried out at the same setup in order to obtain aglycon part, which has pharmaceutical significance. Although pure aglycon could not be achieved, an intermediate compound was obtained based on the HPLC analysis. The developed formulation can be utilized for various life science applications. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim113M050 15-FBE-012This work was supported by the Scientific and Technological Research Council of Turkey, TUBITAK (113M050), and Ege University Research Fund (15-FBE-012). The grant from TUBITAK 2210-C National Graduate Scholarship Program is highly appreciated. Additionally, the authors thank Dr. Ozgur Tag for his support in HPLC analysis. -

Treatment of immobilized ?-amylase under supercritical CO2 conditions: Can activity be enhanced after consecutive enzymatic reactions?

Various approaches have been applied in order to enhance enzyme stability and activity. In this study, the aim was to investigate the capability of supercritical carbon dioxide (SC-CO2) to alter the activity of ?-amylase after consecutive enzymatic reactions. Therefore, ?-amylase from Aspergillus oryzae initially treated with SC-CO2 (29.7 mmol ml-1 min-1) was immobilized in Ca-alginate beads and NaY zeolite, subsequently assayed several times for the hydrolysis of soluble starch and when a lower activity value was recorded compared to the initial activity of the untreated enzyme (17.7 mmol ml-1 min -1), the immobilized samples were retreated with SC-CO2. These consecutive reactions and treatment loops were repeated till the activity cannot be increased with SC-CO2 retreatment in comparison to the initial activity of the untreated enzyme. The best results were achieved with NaY zeolite immobilized samples where four successful loops and seventeen reactions were realized till the residual activity. © 2013 Elsevier B.V. All rights reserved

An integrated process for conversion of Zostera marina residues to bioethanol

Zostera marina is an aquatic plant forming wide grasslands and considered as the lungs of the marine ecosystems. However, the residues reaching the coastlines create nuisance and high costs are required for their disposal. The objective was to investigate the potential of Z. marina residues as a source of secondary metabolites and feedstock in order to propose alternative solutions to the landfill. The supercritical CO 2 extract had a total phenol value of 55.4 mg GAE/g extract and a radical scavenging capacity of 71.4%. Considering the raffinate phase, 3% higher hemicellulose content was reached after supercritical CO 2 treatment. Enzymatic hydrolysis revealed 31.45% and the yield of simultaneous saccharification and fermentation was 8.72% corresponding to a productivity of 0.273 kg/(m 3 h). An integrated process is proposed, where supercritical fluid extraction can act both as the main process to obtain solvent-free pharmaceutical compounds and a pretreatment method in order to loosen the lignin structure, thereby liberating some of the hemicellulose in the matrix. © 2012 Elsevier B.V. All rights reserved.110M790The research fund provided by the Scientific and Technical Research Council of Turkey, TUBITAK ( 110M790 ) is highly appreciated. We also acknowledge Novozyme, Istanbul for donation of Cellic CTec2. -

Downstream processes for plant cell and tissue culture

Biotechnological cultivation of plant cells and tissues is one of the most challenging fields of recent scientific researches. The requirements of pharmaceutical and food industries in terms of value-added phytochemicals have increased rapidly in the last few years. Therefore, cost-effective and technically sound downstream processes have to be developed in order to supply standardized end-products. Depending on the utilization of the biomass or the culture broth, different types of facilities are needed for the recovery and quali-quantitative analysis. The aim of this chapter is to summarize mass transfer considerations and critically outline the developments in downstream processing of plant cell and tissue cultures by presenting fundamental knowledge as well as the advantages and disadvantages of some conventional and novel techniques such as supercritical fluid and membrane processes. Furthermore, state of the art for recovery and purification of secondary metabolites were discussed in the light of patents via Espacenet database covering US, Japan, European, Korean, and Chinese issued and applied patents and WIPO publications. Innovative downstream processes in combination with hyphenated techniques representing a modern approach to perform fast and reproducible analytical methods for quantification and quality assurance of secondary metabolites are major challenges for industrial-scale applications of plant cell and tissue cultures. © 2013 Springer-Verlag Berlin Heidelberg. All rights are reserved