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Marine-Based Carbohydrates as a Valuable Resource for Nutraceuticals and Biotechnological Application
Published in Se-Kwon Kim, Marine Biochemistry, 2023
Rajni Kumari, V. Vivekanand, Nidhi Pareek
Carrageenan is found in red algae with HMW sulfated polysaccharides composed of a linear chain substitution of 1,4,3,6-anhydrogalactose and 1,3-galactose with ester sulfates (15% to 40%) and is a structural part of the cell membranes of red macroalgae (Qureshi et al., 2019). The cell wall of red algae is made up of microfibrils (cellulose and ß1, 3 xylan) and a matrix, where sulfated polysaccharides are present 38% in the form of carrageenan in the matrix (Muthukumar et al., 2021). Commercially used carrageenan’s average molecular weight ranges from 100 to 1000 kDa (Nishinari and Fang, 2021). Carrageenan has three main structures i.e., kappa (κ), iota (ι), and lambda (λ) which contain one, two, and three sulfate groups respectively, in every repeating disaccharide unit (Dong et al., 2021). Usually, commercial kappa, iota, and lambda carrageenan have 22% (w/w), 32% (w/w), and 38% (w/w) sulfate content, respectively; however, this may vary due to the extraction method, algal species, and age groups (Kang et al., 2021). The properties of carrageenan are largely influenced by the number andposition of sulfate ester groups and by the content of 3.6 AG. It is reported that when carrageenan has a higher sulfate ester content, the gel strength reduces (Guan et al., 2017). Carrageenan is used in drug delivery, bone and cartilage tissue regeneration, and wound healing because of its physicochemical properties and gelation mechanism (Yegappan et al., 2018).
Organic Matter
Published in Michael J. Kennish, Ecology of Estuaries Physical and Chemical Aspects, 2019
Detritus feeders poorly assimilate organic detritus, but efficiently utilize the microorganisms attached to the detritus to meet their nutritive requirements.230,256 These organisms can be deficient in enzymes that hydrolyze cellulose, xylan, and other stmctural components of detritus, which limit their ability to assimilate the bulk of this material.236,257,258 Refractory compounds frequently comprise much of the nonmicrobial detrital nitrogen,259 whereas bacteria are 40 to 80% protein on a dry-weight basis and a high-quality food source.260 Contradictions remain in the literature, however, concerning proportions of the macro-detritivore diet attributable to microorganisms associated with detritus, mucopolysaccharides of microbial origin, and detritus devoid of microbes. Difficulties in obtaining quantitative measures of total microbial activity, growth rate, and biomass have complicated studies of detritus decomposition and utilization.261 Hanson261 elaborates on techniques used to assess microbial activities during the decay and utilization of detritus.
Seaweed Antimicrobials
Published in Gokare A. Ravishankar, Ranga Rao Ambati, Handbook of Algal Technologies and Phytochemicals, 2019
María José Pérez, Elena Falqué, Herminia Domínguez
Seaweeds are a great source of bioactive compounds due to the large number of secondary metabolites they synthesize and possess antioxidant and some phytochemical activities. According to the literature (Michalak and Chojnacka 2015) they are a rich source of carbohydrates (brown algae [Phaeophyta]: alginate, fucoidan, laminarin; red algae [Rhodophyta]: agar, carrageenan, porphyran, mannan, xylan; green algae [Chlorophyta]: cellulose, xylan, ulvan), proteins, minerals, vitamins, oils, fats, polyunsaturated fatty acids and other bioactive compounds (polyphenols, pigments, etc.). The different seaweed compound families are presented in Figure 6.1.
Microbially-derived cocktail of carbohydrases as an anti-biofouling agents: a ‘green approach’
Published in Biofouling, 2022
Harmanpreet Kaur, Arashdeep Kaur, Sanjeev Kumar Soni, Praveen Rishi
Xylanases are glycosidases that hydrolyze β-1,4 glycoside linkages joining the monomeric units in xylan. Most of the xylanases are extracellular as xylan cannot enter the cell due to its large size (Bhardwaj et al. 2019). Actinomycetes, Aspergillus, Trichoderma, Phanerochaetes, Clostridium, and Bacillus species are prominent producers of xylanolytic enzymes. Xylanases have potential applications in various industries, for instance, the food industry (production of wine, animal feed, processing of fruit and vegetables, bakeries, and breweries), paper and pulp industry, textile industry, and bioremediation (Subramaniyan and Prema 2002; Walia et al. 2017). A study by Lee et al. (2018) demonstrated the antibiofilm activity of thermostable xylanase against two different strains of P. aeruginosa, PAO1 and PA14, MRSA, and E. coli, wherein xylanase inhibited their biofilms without affecting the planktonic growth. Furthermore, to improve the efficacy of xylanase application in clinical settings, Lee et al. (2018) evaluated the effect of the xylanase-gentamycin combination on the susceptibility of P. aeruginosa biofilm cells. The study reported that the survival of P. aeruginosa biofilm cells was significantly reduced due to the xylanase treatment. Thus, it was inferred that xylanases alone or combined with other antimicrobial agents hold significance to control persistent biofilms.
The Impact of Migration on the Gut Metagenome of South Asian Canadians
Published in Gut Microbes, 2021
Julia K. Copeland, Gary Chao, Shelley Vanderhout, Erica Acton, Pauline W. Wang, Eric I. Benchimol, Ahmed El-Sohemy, Ken Croitoru, Jennifer L. Gommerman, David S. Guttman
Bacteroides and Bifidobacterium species are known to possess multiple gene families capable of polysaccharide and monosaccharide degradation and can often switch between energy sources.70 The flexibility of what nutrients Bacteroides and Bifidobacterium can utilize may indicate that these species are less reliant on interspecies cross-feeding.71 We hypothesize that the negative correlation between the abundance of P. copri and both B. longum and B. uniformis, may be due to redundancy in certain functions, such as xylan degradation. Without dietary fibers, certain species, particularly from the genus Bacteroides, will ferment host mucin glycans, creating a potentially proinflammatory environment.42,72,73 Other degraders, such as P. copri, though capable of breaking down the xylan backbone of mucin, do not contain the enzymes required to further debranch the attached sugars (Figure 6a). Previous research determined that the P. copri 1,4-beta-xylanase was present in 94% in vegans and only 58% in omnivores,74 and that individuals who consume a diet rich in cellulose and xylan have gut communities with high abundances of Prevotella.75,76 This suggests that Prevotella-based xylan degradation is favored when exposed to consistent, high levels of complex carbohydrates, while B. longum and B. uniformis xylan degradation may be favored when the function is only required sporadically, and a range of other nutrient sources are often introduced to the gut.
Evaluation of the genotoxicity and teratogenicity of xylan using different model approaches
Published in Drug and Chemical Toxicology, 2022
Guangqiu Qin, Yuqiu Gao, Pingjing Wen, Guiqiang Liang, Peng Zhao, Baiqing Dong, Song Tang, Kamran Shekh
Xylan is the most common group of hemicelluloses and the second most abundant polysaccharide among the photosynthetic products of plants (Ebringerová and Heinze 2000). They may constitute up to 50% of the dry mass in certain cereal grains (Ebringerová and Heinze 2000). Xylans consist of a backbone of β-(1–4)-linked xylose units with attached groups of glucose, xylose, mannose, galactose, arabinose, fucose, glucuronic acid, or galacturonic acid, depending on the natural source (Heinze et al.2003).