Biomacromolecules from Marine Organisms and Their Biomedical Application
Se-Kwon Kim in Marine Biochemistry, 2023
Extracellular Polymeric Substances (EPSs): Various marine microbes produced complex substances composed of carbohydrates, proteins, humic substances, lipids and nucleic acids (Manivasagan and Kim, 2014) are known as EPSs. It consists of organic and inorganic substances along with acetate, pyruvate, phosphate and succinate moieties (Priyanka and Ena, 2020). Enormous EPS-producing Vibrio furnissi VB0S3 was isolated from the coastal area of Goa (Bramhachari et al., 2007). Similarly, an Enterobacter cloaca was isolated from marine sediment, which has produced enormous acidic EPS exhibits significant emulsifying properties (Iyer et al., 2005). A gram-positive bacteria Planococcus maitriensis was isolated from the coastal waters of Bhavnagar in India produced an EPS used in oil recovery and bioremediation of oil (Priyanka and Ena, 2020). Marine bacterium Alteronomas sp., Pseudoaltromonas sp., and Vibrio sp., produced unique EPSs ranged from 0.5 to 4 g per liter of sugar base medium (Raza et al., 2011). The EPS from Vibrio diabolicus has composed with glucosamine and glucuronic acid (Arias et al., 2003).
Polysaccharides from Marine Micro- and Macro-Organisms
Se-Kwon Kim in Marine Biochemistry, 2023
Marine organisms are known to produce various biopolymeric substances which are classified into polysaccharides, amino acids, and proteins (McNaught and Wilkinson, 1997). Among the polysaccharides, the sulfated polymer glycosaminoglycans are different from the other polymer by their constitution of hexamine and hexose unit that forms proteoglycans in the organism (Hardingham and Aosang, 1992). Microbes are well known to grow everywhere on the earth, especially in the marine environment, which is the reason for the major primary production which includes polysaccharides and other organic substances (Abreu and Taga, 2016; Field et al., 1998). Extracellular polymeric substances from microbes are used in the solubilization of hydrophobic organic chemicals and cationic species (Santschi et al., 1998). These cationic polysaccharides are endorsed with a high level of uronic acid with different amino acids COO-, SO4 and C-O- (Bhaskar and Bhosle, 2005). Also, the hydrophobic and hydrophilic nature of the polymers depends on the amino acid, peptide, and proteins connected with polysaccharides (Gutierrez et al., 2009). In addition, marine polysaccharides are thick in nature, stable, and good emulsifiers (Kaplan, 1998). Recently, silicon with alginate in rechargeable batteries was shown to perform eight times more than the batteries with a graphite anode (Ryou et al., 2013). Furthermore, marine polysaccharides have stable clips, substitute human tissue, manufacture of the biodegradable capsules, and potential wound healing activity. Heterogeneous biodegradable polysaccharide starch carries the drug in the form of foam into the human tissue.
Microbial Biofilms
Chaminda Jayampath Seneviratne in Microbial Biofilms, 2017
The development of microcolonies is followed by the maturation of the biofilm into a spatially organised three-dimensional community. Though the demarcations between young and mature biofilms are not always clear, certain hallmark features such as the formation of extracellular matrix encasing the microbial community help in distinguishing the mature from the young biofilms [27]. The exopolymeric matrix surrounding the biofilms has also been termed a ‘slime layer’ in the past [16]. This layer of extracellular polymeric substances (EPS) provides various advantages to the biofilm community such as facilitating adhesion to surfaces, enabling the development of multilayered biofilm and serving as a barrier to influx of drugs and other toxic substances. The EPS layer comprises various components with different chemical natures such as exopolysaccharides, proteins, eDNA and other polymers [30]. While the EPS confer the mature architecture of the biofilms, the shape of mature biofilms is determined by various environmental factors, particularly the flow conditions in the immediate environment. Depending on the fluid flow rates, bacteria such as P. aeruginosa and V. cholerae have been shown to develop mushroom stalk architecture biofilms indicating the onset of maturation [31,32]. Development of EPS observed in vivo using labeling strategies in V. cholerae biofilms has shown distinct levels of spatial organisation [33]. In general, the EPS may act as a physical barrier that prevents the access of antimicrobials to cells embedded in the biofilm community, in turn contributing to enhanced drug resistance. This hindrance is thought to depend largely on the amount and nature of the EPS, as well as the physicochemical properties of the drug.
Algal extracellular polymeric substances (algal-EPS) for mitigating the combined toxic effects of polystyrene nanoplastics and nano-TiO2 in Chlorella sp.
Published in Nanotoxicology, 2023
Lokeshwari Natarajan, M. Annie Jenifer, Willie J. G. M. Peijnenburg, Amitava Mukherjee
One of the critical gaps in the current ecotoxicological studies of nanomaterials lies in ignoring the role of naturally occurring biopolymers in modulating their physico-chemical as well as biological interactions. Extracellular Polymeric Substances (EPS) areone such natural biopolymer that often functions as a barrier to pollutants. EPS constitutes a key component of microalgae. Algae produce EPS for a variety of reasons, including (a) secure attachment and improvement of the local environment, and (b) as a metabolic waste. Notably, EPS secretion boosts cell survival, metabolic efficacy, and adaptability (Decho and Gutierrez 2017). These biopolymers can easily adsorb to nanomaterials in the aquatic environment, modulating their bioactivity, cytotoxicity, and physiological features (Alimi et al. 2018). This phenomenon is often referred to as eco-corona formation, the effects of which need to be considered while formulating an experimental design for nano-ecotoxicity studies in aquatic organisms.
Effect of silica nano-spheres on adhesion of oral bacteria and human fibroblasts
Published in Biomaterial Investigations in Dentistry, 2020
Pawel Kallas, Hua Kang, Håkon Valen, Håvard Jostein Haugen, Martin Andersson, Mats Hulander
A biofilm is a biological community consisting of bacteria and a layer of organic and inorganic substances produced by these organisms [8]. Its formation on implant surfaces may lead to infection and breakdown of the implant supporting tissue [9,10]. The infection commences from the initial attachment of bacteria onto the implant surface followed by colonization and biofilm formation as previously described by Busscher et al. [11]. In the oral environment, both on teeth and dental implants, early colonizers (mainly oral streptococci) attach to the surface in the first place, initiating formation of biofilm [12–15]. Other microorganisms attach themselves to the extracellular polymeric substance (EPS) matrix in the biofilm or to already adhered bacteria. It has been shown that bacterial colonization of trans-mucosal implants occurs within 30 min after placement [16,17]. The establishment of a biofilm makes dental implant surfaces prone to infections and biomaterials associated infections (BAI) have been shown to be one of the leading causes of implant failure [18]. Microorganisms that grow in biofilm, compared to planktonic, free-floating cells, are much less sensitive towards different types of antibacterial treatments. Bacterial cells, which are an integral part of the biofilm, are characterized by a much higher resistance to conventional antibiotics compared to planktonic bacteria [19–21]. Additionally, the extracellular polymeric substance acts as a physical barrier that protects the bacteria from the host’s immune system [22].
Mini-review: efficacy of lytic bacteriophages on multispecies biofilms
Published in Biofouling, 2019
Legesse Geredew Kifelew, James G. Mitchell, Peter Speck
A bacterial biofilm is a group of bacteria attached to each other and usually to a surface (Allewell 2016; O'Toole et al. 2000; Skillman et al. 1998). The bacterial community in the biofilm is encased in an extracellular matrix; bacteria in this form are found ubiquitously in the environment (Teh et al. 2014; Kostakioti et al. 2013). This matrix is mainly composed of polysaccharides, proteins, lipids and DNA, and is often referred to as extracellular polymeric substance (EPS) (Teh et al. 2014; Karunakaran et al. 2011). Studies of EPS show that it reduces microbial mobility and limits the transfer of nutrients and oxygen (Steenackers et al. 2016). In addition, the matrix contributes to the development of an anaerobic environment and structural heterogeneity in biofilms (Lacroix-Gueu et al. 2005). Inside the matrix, the biofilm may consist of densely populated single or multiple species of bacteria (De Beer and Stoodley 2006). Scanning electron microscopy and related techniques reveal the micro-heterogeneity of biofilms, with variable distribution of cells, matrix, and fluid-filled channels and pores (Wood et al. 2000). Natural biofilms are a mixture of micro-organisms sharing a common milieu and coexisting in niches by forming multispecies biofilms (Thein et al. 2007). Natural biofilms are usually polymicrobial, and bacteria occupy 5%–30% of the volume of the biofilm (Zhao et al. 2013).