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Engineering of Saccharomyces cerevisiae for efficient fermentation of cellulose.
Oh, EJ, Jin, YS
FEMS yeast research. 2020;(1)
Abstract
Conversion of lignocellulosic biomass to biofuels using microbial fermentation is an attractive option to substitute petroleum-based production economically and sustainably. The substantial efforts to design yeast strains for biomass hydrolysis have led to industrially applicable biological routes. Saccharomyces cerevisiae is a robust microbial platform widely used in biofuel production, based on its amenability to systems and synthetic biology tools. The critical challenges for the efficient microbial conversion of lignocellulosic biomass by engineered S. cerevisiae include heterologous expression of cellulolytic enzymes, co-fermentation of hexose and pentose sugars, and robustness against various stresses. Scientists developed many engineering strategies for cellulolytic S. cerevisiae strains, bringing the application of consolidated bioprocess at an industrial scale. Recent advances in the development and implementation of engineered yeast strains capable of assimilating lignocellulose will be reviewed.
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Applications of Cellulose-based Materials in Sustained Drug Delivery Systems.
Sun, B, Zhang, M, Shen, J, He, Z, Fatehi, P, Ni, Y
Current medicinal chemistry. 2019;(14):2485-2501
Abstract
Bio-compatible, bio-degradable, and bio-available excipients are of critical interest for drug delivery systems. Cellulose and its derivative-based excipients have been well studied due to their green/natural and unique encapsulation/binding properties. They are often used in controlled/sustained drug delivery systems. In these applications, cellulose and its derivatives function generally can modify the solubility/gelling behavior of drugs, resulting in different mechanisms for controlling the release profiles of drugs. In this paper, the current knowledge in the structure and chemistry of conventional cellulose derivatives, and their applications in drug delivery systems are briefly reviewed. The development of innovative cellulose-based materials, including micro-cellulose (MC) and nano-cellulose (NC) in the applications of sustained drug delivery, is also discussed.
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Bacterial cellulose skin masks-Properties and sensory tests.
Pacheco, G, de Mello, CV, Chiari-Andréo, BG, Isaac, VLB, Ribeiro, SJL, Pecoraro, É, Trovatti, E
Journal of cosmetic dermatology. 2018;(5):840-847
Abstract
BACKGROUND Bacterial cellulose (BC) is a versatile material produced by microorganisms in the form of a membranous hydrogel, totally biocompatible, and endowed with high mechanical strength. Its high water-holding capacity based on its highly porous nanofibrillar structure allows BC to incorporate and to release substances very fast, thus being suitable for the preparation of skincare masks. AIMS The preparation and characterization of cosmetic masks based on BC membranes and active cosmetics. METHODS The masks were prepared by the simple incorporation of the cosmetic actives into BC membranes, used as a swelling matrix. The masks were characterized by Fourier transform infrared (FTIR), scanning electron microscopy (SEM), sensory tests, and skin moisture tests on volunteers. RESULTS The results of sensory tests revealed the good performance of BC, being considered effective by the panel of volunteers, specially for adhesion to the skin (7.7 at the score scale), and improvement of the skin moisture (the hydration effect increased 76% in 75% of the volunteers that used vegetable extract mask formulation [VEM]), or a decrease in skin hydration (80% of the volunteers showed 32.6% decrease on skin hydration using propolis extract formulation [PEM] treatment), indicating the BC nanofiber membranes can be used to skincare applications. CONCLUSION The results demonstrate the BC can be used as an alternative support for cosmetic actives for skin treatment.
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[Optimization of Nasal Drug Absorption from Powder Formulations: The Feasibility of Controlling Drug Absorption by the Use of Pharmaceutical Excipients].
Tanaka, A
Yakugaku zasshi : Journal of the Pharmaceutical Society of Japan. 2018;(12):1467-1472
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Abstract
Nasal application of powder formulations has garnered attention because of its significant potential for systemic drug delivery. Because a powder drug must first diffuse from the formulation and dissolve in the nasal cavity fluid before transepithelial permeation, dissolution and diffusion are distinct but important factors for nasal drug absorption. Since the formulation is directly administered onto the nasal mucosal surface, the effect of excipients on drug absorption may be significant. Therefore, the influence of excipients on nasal drug absorption was evaluated. Three types of hydroxypropyl cellulose (HPC) [HPC (SL), HPC (M), and HPC (H)], lactose, and sodium chloride (NaCl) were used as excipients. Warfarin (WF), piroxicam (PXC), sumatriptan (STP), and norfloxacin (NFX) were selected as model drugs. HPC (M) enhanced the absorption of PXC, while both HPC (M) and HPC (H) enhanced the absorption of STP. All three HPCs failed to enhance the absorption of WF. An increase in the polymerization degree of HPCs decreased the diffusion of drugs in HPC solutions, but prolonged their nasal retention. Lactose and NaCl increased the fluid volume on the nasal mucosal surface by increasing the osmotic pressure, thereby enhancing the nasal absorption of PXC and NFX; however, lactose and NaCl accelerated the nasal clearance of these. These results indicate that nasal drug absorption from powder formulations can be controlled by excipients.
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Chloroplasts as Cellular Factories for the Cost-effective Production of Cellulases.
Khan, MO, Mehmood, MA, Mukhtar, Z, Ahmad, N
Protein and peptide letters. 2018;(2):129-135
Abstract
Chloroplasts are vital photosynthetic organelles in plant cells that carry out several important cellular functions including synthesis of amino acids, fatty acids, and lipids and metabolism of nitrogen, starch, and Sulphur to sustain the homeostasis in plants. These organelles have got their own genome, and related genetic machinery to synthesize required proteins for various plant functions. Genetic manipulations of the chloroplast genome for different biotech applications has been of great interest due to desired features including the availability of operonal mode of gene expression, high copy number, and maternal mode of inheritance (in the most field crops). Their capacity to often express transgenes at high levels make it a cost-effective platform for the production of foreign proteins, particularly high-value targets of industrial importance, at large scale. This article reviews briefly the research work carried out to produce cellulolytic enzymes in higher plant chloroplasts. The challenges and future opportunities for the same are also discussed.
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Sticking to cellulose: exploiting Arabidopsis seed coat mucilage to understand cellulose biosynthesis and cell wall polysaccharide interactions.
Griffiths, JS, North, HM
The New phytologist. 2017;(3):959-966
Abstract
The cell wall defines the shape of cells and ultimately plant architecture. It provides mechanical resistance to osmotic pressure while still being malleable and allowing cells to grow and divide. These properties are determined by the different components of the wall and the interactions between them. The major components of the cell wall are the polysaccharides cellulose, hemicellulose and pectin. Cellulose biosynthesis has been extensively studied in Arabidopsis hypocotyls, and more recently in the mucilage-producing epidermal cells of the seed coat. The latter has emerged as an excellent system to study cellulose biosynthesis and the interactions between cellulose and other cell wall polymers. Here we review some of the major advances in our understanding of cellulose biosynthesis in the seed coat, and how mucilage has aided our understanding of the interactions between cellulose and other cell wall components required for wall cohesion. Recently, 10 genes involved in cellulose or hemicellulose biosynthesis in mucilage have been identified. These discoveries have helped to demonstrate that xylan side-chains on rhamnogalacturonan I act to link this pectin directly to cellulose. We also examine other factors that, either directly or indirectly, influence cellulose organization or crystallization in mucilage.
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Regulation of cellulose synthesis in response to stress.
Kesten, C, Menna, A, Sánchez-Rodríguez, C
Current opinion in plant biology. 2017;:106-113
Abstract
The cell wall is a complex polysaccharide network that provides stability and protection to the plant and is one of the first layers of biotic and abiotic stimuli perception. A controlled remodeling of the primary cell wall is essential for the plant to adapt its growth to environmental stresses. Cellulose, the main component of plant cell walls is synthesized by plasma membrane-localized cellulose synthases moving along cortical microtubule tracks. Recent advancements demonstrate a tight regulation of cellulose synthesis at the primary cell wall by phytohormone networks. Stress-induced perturbations at the cell wall that modify cellulose synthesis and microtubule arrangement activate similar phytohormone-based stress response pathways. The integration of stress perception at the primary cell wall and downstream responses are likely to be tightly regulated by phytohormone signaling pathways in the context of cellulose synthesis and microtubule arrangement.
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Functionality and nutritional aspects of microcrystalline cellulose in food.
Nsor-Atindana, J, Chen, M, Goff, HD, Zhong, F, Sharif, HR, Li, Y
Carbohydrate polymers. 2017;:159-174
Abstract
Microcrystalline cellulose (MCC) is among the most commonly used cellulose derivatives in the food industry. In order assess the recent advances of MCC in food product development and its associated nutraceutical implications, google scholar and database of journals subscribed by Jiangnan university, China were used to source literature. Recently published research articles that reported physicochemical properties of MCC for food application or potential application in food and nutraceutical functions were reviewed and major findings outlined. The selected literature reviewed demonstrated that the material has been extensively explored as a functional ingredient in food including meat products, emulsions, beverages, dairy products, bakery, confectionary and filling. The carbohydrate polymer also has many promising applications in functional and nutraceutical food industries. Though widely used as control for many dietary fiber investigations, MCC has been shown to provide positive effects on gastrointestinal physiology, and hypolipidemic effects, influencing the expression of enzymes involved in lipid metabolism. These techno-functional and nutraceutical properties of MCC are influenced by the physicochemical of the material, which are defined by the raw material source and processing conditions. Apart from these functional properties, this review also highlighted limitations and gaps regarding the application of material in food and nutritional realms. Functional, Nutritional and health claims of MCC.
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The impact of abiotic factors on cellulose synthesis.
Wang, T, McFarlane, HE, Persson, S
Journal of experimental botany. 2016;(2):543-52
Abstract
As sessile organisms, plants require mechanisms to sense and respond to changes in their environment, including both biotic and abiotic factors. One of the most common plant adaptations to environmental changes is differential regulation of growth, which results in growth either away from adverse conditions or towards more favorable conditions. As cell walls shape plant growth, this differential growth response must be accompanied by alterations to the plant cell wall. Here, we review the impact of four abiotic factors (osmotic conditions, ionic stress, light, and temperature) on the synthesis of cellulose, an important component of the plant cell wall. Understanding how different abiotic factors influence cellulose production and addressing key questions that remain in this field can provide crucial information to cope with the need for increased crop production under the mounting pressures of a growing world population and global climate change.
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Cellulose and callose synthesis and organization in focus, what's new?
Schneider, R, Hanak, T, Persson, S, Voigt, CA
Current opinion in plant biology. 2016;:9-16
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Abstract
Plant growth and development are supported by plastic but strong cell walls. These walls consist largely of polysaccharides that vary in content and structure. Most of the polysaccharides are produced in the Golgi apparatus and are then secreted to the apoplast and built into the growing walls. However, the two glucan polymers cellulose and callose are synthesized at the plasma membrane by cellulose or callose synthase complexes, respectively. Cellulose is the most common cell wall polymer in land plants and provides strength to the walls to support directed cell expansion. In contrast, callose is integral to specialized cell walls, such as the cell plate that separates dividing cells and growing pollen tube walls, and maintains important functions during abiotic and biotic stress responses. The last years have seen a dramatic increase in our understanding of how cellulose and callose are manufactured, and new factors that regulate the synthases have been identified. Much of this knowledge has been amassed via various microscopy-based techniques, including various confocal techniques and super-resolution imaging. Here, we summarize and synthesize recent findings in the fields of cellulose and callose synthesis in plant biology.