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Cell Biology for Bioprocessing
Published in Wei-Shou Hu, Cell Culture Bioprocess Engineering, 2020
Three types of lipids make up the lipid bilayer membrane in cells and organelles: phospholipids, glycolipids, and gangliosides (phospholipids being the most common) (Panel 2.5). There are several different types of phospholipids. The most abundant type is glycerophospholipid, which uses glycerol as the backbone. Its 3-hydroxyal group of glycerol is linked to a phosphate group, to which an ethanolamine or serine is attached. The other two hydroxyl groups of glycerol are linked to two fatty acids through an ester bond. Typically, one of those two fatty acids is saturated and the other is unsaturated, with a cis double bond in between C14 and C24 (Panel 2.6). The degree of unsaturation affects the packing of the lipid bilayer. Saturated fatty acids allow more dense packing, while the double bonds in the unsaturated fatty acids create kinks, which reduce packing and increase the membrane fluidity.
Biomolecules and Complex Biological Entities
Published in Simona Badilescu, Muthukumaran Packirisamy, BioMEMS, 2016
Simona Badilescu, Muthukumaran Packirisamy
Cell membranes also contain cholesterol in the hydrophobic areas. Cholesterol is thought to enhance the flexibility of a cell membrane. Proteins, in the inner surface of the membrane called integral or gateway proteins, allow certain molecules to move through the protein channel. Carbohydrates are also attached to integral proteins. The outer surface of the membrane is rich in glycolipids. Their hydrophobic tails are embedded in the hydrophobic region of the membrane, and their hydrophilic heads exposed outside the cell. Plant cells have walls located outside the membrane that contain cellulose (a polysaccharide), and some plants have lignin and other chemicals in their wall as well. Because animal cells lack a cell wall, their membrane maintains the integrity of the cell. The nucleus, shown in Figure 3.47, exists only in eukaryotic cells.
Macrocyclic Receptors for Biomolecules and Biochemical Sensing
Published in Satish Kumar, Priya Ranjan Sahoo, Violet Rajeshwari Macwan, Jaspreet Kaur, Mukesh, Rachana Sahney, Macrocyclic Receptors for Environmental and Biosensing Applications, 2022
Satish Kumar, Priya Ranjan Sahoo, Violet Rajeshwari Macwan, Jaspreet Kaur, Mukesh, Rachana Sahney
Carbohydrates are the most important and abundant substrate in biology. They are the building blocks for a more complex molecule like genetic material, important for cellular functions like energy generation and act as building materials in plants (cellulose). Carbohydrates are defined as polyhydroxy hydrocarbon, mainly divided into four groups: monosaccharides, disaccharides, oligosaccharides and polysaccharides. Three-dimensional structures of carbohydrates represent the spatial arrangements of individual sugar residues. Most commonly occurring mammalian complex carbohydrates consist of sugar residues that exist in the pyranose ring form, the most stable and rigid conformation of which are the chair forms. When two sugar residues are joined together covalently in a glycosidic linkage, the monomer units are free to rotate around the glycosidic oxygen atom between the two rings, and the resulting disaccharide can therefore assume a number of different conformations corresponding to the rotations about these two bonds. The most common monosaccharide is glucose which can exist in a six-membered (pyranose) or five-membered (furanose) ring structure is shown in Fig. 7.12 (Wikipedia). Simple monosaccharides are usually neutral, hydrophilic and possess a geometrically well-defined structure with peripheral hydroxyl groups. Some hydroxyl groups in monosaccharides can be modified and converted into other polar functionalities like amines, acylated amines, sulfates or carboxylates. Figure 7.13 shows the most abundant monosaccharide units, which are used as building blocks to create mammalian oligosaccharide structures (Peters 2014). Inside the cell, monosaccharide units polymerize in a step-wise manner to form oligosaccharides containing 3–10 monomer units. The cellular process of glycosylation (Cummings 2009) in the cells synthesizes glycolipids and glycoproteins important as cell-surface receptors, cell-adhesion molecules, immunoglobulins and tumor antigens (Elbein 1991). Oligosaccharides bound to lipid molecules are known as glycolipids important for cell recognition. Molecular recognition of sugars play an important role in different biological events, occurring in living organisms such as immune response (Lehrringer 1982; Engström et al. 2005), viral and bacterial infection (Williams and Davies 2001; Olofsson and Bergström 2005), drug activity (Okamoto et al. 1997), metastasis of tumor cells (Gorelik et al. 2001), stem cell differentiation and cell-cell adhesion. Perhaps the most well-known saccharide is ß-D-Glucose — a biomarker for diabetes that could be detected using synthetic receptors. The ligand-receptor sensing could be exploited for blood glucose monitoring (Sun and James 2015) and delivery of glucose-responsive insulin (Bakh et al. 2017). Thus molecular recognition of different carbohydrates by macrocycle could be used for the development of synthetic antibodies for cancer cells, anti-infectives, anti-inflammatories and many diagnostic applications (Solis et al. 2015; Francesconi and Roelens 2019; Tommasone et al. 2019).
Current status and future prospects of biological routes to bio-based products using raw materials, wastes, and residues as renewable resources
Published in Critical Reviews in Environmental Science and Technology, 2022
Ji-Young Lee, Sung-Eun Lee, Dong-Woo Lee
Various renewable sources and agro-industrial or food wastes have been used for low-molecular weight biosurfactant production using microorganisms (Figure 4). Waste frying oil, molasses, animal fat, industrial waste (crude glycerol), and whey are examples of low-cost substrates that have been employed for microbial growth (Table 2). Candida bombicola and Candida apicola are major producers of sophorolipids. Microbial fermentation of sweet sorghum bagasse supplemented with yellow grease using C. bombicola produced 35.9 g/L of sophorolipids with a high production yield of 0.56 g/g (Samad et al., 2017). Moreover, Pseudomonas aeruginosa is a well-known producer of rhamnolipids, key components of microbial biosurfactants. Recently, it was reported that P. aeruginosa can produce rhamnolipids from waste frying coconut oil (George & Jayachandran, 2013) and soybean soapstock (Nitschke et al., 2005) as the sole carbon source. In particular, biosurfactant production by P. aeruginosa in a 3 L-scale fermenter potentiated industrial production using waste motor lubricant oil and peanut oil cake (Thavasi, Nambaru, et al., 2011). These glycolipids offer a wide range of applications in the pharmaceutical and cosmetic fields. Moreover, low molecular weight surfactants (lipopeptides) are produced by Bacillus strains. Bacillus subtilis MTCC 2423 produces surfactin, another key component of biosurfactants, from waste frying sunflower and rice bran oils (Vedaraman & Venkatesh, 2011).
Glycolipids from natural sources: dry liquid crystal properties, hydrogen bonding and molecular mobility of Palm Kernel oil mannosides
Published in Liquid Crystals, 2020
Alfonso Martinez-Felipe, Thamil Selvi Velayutham, Nurul Fadhilah Kamalul Aripin, Marina Yusoff, Emma Farquharson, Rauzah Hashim
Interest in eco-friendly surfactants continues to increase as a way to prepare new formulations for cosmetic and biomedical applications. Glycolipids are very attractive candidates as non-ionic surfactants due to their amphiphilic character, resulting from their polar sugar head linked to the hydrophobic alkyl tail via a glycosidic bond. This enables the molecules to self-assemble by thermal and solvent effects, giving rise to thermotropic and lyotropic liquid crystalline behaviour that can be applied in a wide range of nano-and biotechnology areas [1,2]. Glycolipids can be advantageous to conventional ionic surfactants due to their biodegradable and non-toxic character, and possess the additional quality of being derived from common and cheap natural resources [2,3]. Glycolipids can be found, for example, in cell membranes, and are known to be involved in cellular functions [4], making them suitable for targeted drug delivery systems [5,6]. Alkyl polyglycosides, APG, are already commercially available as non-toxic surfactants used as microemulsions, detergents and cleaners [7].
Characterization and oil recovery application of biosurfactant produced during bioremediation of waste engine oil by strain Pseudomonas aeruginosa gi|KP 16392| isolated from Sambhar salt lake
Published in Bioremediation Journal, 2021
Shailee Gaur, Suresh Gupta, Amit Jain
Biosurfactants have been reported to be classified based on the producer microbe and the substrate provided to the microbes (R. de C. F. S. Silva, et al. 2014). They are structurally very diverse groups of molecules which makes them a new tool for various activities in different sectors (Ramkrishna 2010). The classification of biosurfactants on the basis of their chemical composition is as follows: (i) Glycolipids which are carbohydrates (mono-, di-, tri- and tetra-) including glucose, rhamnose, etc. combined with long-chain aliphatic acids or hydroxy aliphatic acids, some examples include Rhamnolipids, Trehalose Lipids and Sophorolipids; (ii) Lipopeptides which are molecules consisting of a lipid connected to a peptide, some examples are Surfactin, Fengycin, Iturin and Lichenysin; (iii) Fatty Acid biosurfactants produced on the cellular surface of certain hydrocarbon degrading microbes when grown on alkanes are mostly saturated fatty acids with C12–C14 range, although can sometimes be complex with hydroxyl groups and alkyl branches; (iv) Polymeric biosurfactants are the compounds which exhibit properties like high viscosity, tensile strength and shear resistance and possess high molecular weight, some examples of this class are Emulsan, Biodispersan, Alasan and Liposan and (v) Particulate biosurfactants which are extracellular membrane vesicles of microbial cells to facilitate the emulsification of hydrocarbons; composed mainly of proteins, lipopolysaccharides and phospholipids. The classification of biosurfactants along with their producing species and application is shown in Table 1.