Bacterial System for Alginate Uptake and Degradation

Hashimoto, Wataru; Maruyama, Yukie; Itoh, Takafumi; Mikami, Bunzo; Murata, Kousaku

doi:10.1007/978-3-540-92679-5_3

Cited by 4 publications

(2 citation statements)

References 71 publications

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“…Alginate is a linear polysaccharide composed of α-l-guluronate (G) and β-d-mannuronate (M) subunits. The G and M subunits are linked via 1,4-glycosidic bonds and are arranged in the form of polyM, polyG, and polyMG blocks (Table 2) (Renn, 1997;Draget et al, 2005;Hashimoto et al, 2009).…”

Section: Algal Sugarmentioning

confidence: 99%

“…The degradation of alginate into unsaturated alginate oligomers (degree of polymerization 2-4) is carried out by endo-alginate (1) hexokinase, (2) Glucose-6-P isomerase, (3) 6-phosphofructokinase, (4) fructose-biP aldolase, (5) glucose-6-P dehydrogenase (NADP + ), (6) 6-phosphogluconolactonase, (7) phosphogluconate dehydratase, (8) KDPG aldolase, (9) glyceraldehyde 3-P dehydrogenase (EC 1.2.1.12), (10) phosphoglycerate kinase (EC 2.7.2.3), (11) phosphoglycerate mutase (EC 5.4.2.11), (12) phosphopyruvate hydratase (enolase; EC 4.2.1.11), (13) pyruvate kinase (EC 2.7.1.40), (14) pyruvate decarboxylase, and (15) Hashimoto et al (2009) andWong et al (2000)]. In the next step, alginate oligomers are cleaved into unsaturated monosaccharides [4-deoxy-α-l-erythro-hex-4-enopyranuronate (DEHEP)] by exo-acting oligoalginate lyases (EC 4.2.2.26).…”

Section: Conversion Of Alginate To Uronic Acid Monomersmentioning

confidence: 99%

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The Enzymatic Conversion of Major Algal and Cyanobacterial Carbohydrates to Bioethanol

2016

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The production of fuels from biomass is categorized as first-, second-, or thirdgeneration depending upon the source of raw materials, either food crops, lignocellulosic material, or algal biomass, respectively. Thus far, the emphasis has been on using food crops creating several environmental problems. To overcome these problems, there is a shift toward bioenergy production from non-food sources. Algae, which store high amounts of carbohydrates, are a potential producer of raw materials for sustainable production of bioethanol. Algae store their carbohydrates in the form of food storage sugars and structural material. In general, algal food storage polysaccharides are composed of glucose subunits; however, they vary in the glycosidic bond that links the glucose molecules. In starch-type polysaccharides (starch, floridean starch, and glycogen), the glucose subunits are linked together by α-(1→4) and α-(1→6) glycosidic bonds. Laminarin-type polysaccharides (laminarin, chrysolaminarin, and paramylon) are made of glucose subunits that are linked together by β-(1→3) and β-(1→6) glycosidic bonds. In contrast to food storage polysaccharides, structural polysaccharides vary in composition and glycosidic bond. The industrial production of bioethanol from algae requires efficient hydrolysis and fermentation of different algal sugars. However, the hydrolysis of algal polysaccharides employs more enzymatic mixes in comparison to terrestrial plants. Similarly, algal fermentable sugars display more diversity than plants, and therefore more metabolic pathways are required to produce ethanol from these sugars. In general, the fermentation of glucose, galactose, and glucose isomers is carried out by wild-type strains of Saccharomyces cerevisiae and Zymomonas mobilis. In these strains, glucose enters glycolysis, where is it converted to pyruvate through either Embden-Meyerhof-Parnas pathway or Entner-Doudoroff pathway. Other monosaccharides must be converted to fermentable sugars before entering glycolysis. In contrast, microbial wild-type strains are not capable of producing ethanol from alginate, and therefore the production of bioethanol from alginate was achieved by using genetically engineered microbial strains, which can simultaneously hydrolyze and ferment alginate to ethanol. In this review, we emphasize the enzymatic hydrolysis processes of different algal polysaccharides. Additionally, we highlight the major metabolic pathways that are employed to ferment different algal monosaccharides to ethanol.

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Section: Algal Sugarmentioning

confidence: 99%

Section: Conversion Of Alginate To Uronic Acid Monomersmentioning

confidence: 99%

The Enzymatic Conversion of Major Algal and Cyanobacterial Carbohydrates to Bioethanol

2016

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Enzymatic Alginate Modification

Ertesvåg

Valla

Skjåk‐Bræk

2009

Alginates: Biology and Applications

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Bacteria with a mouth: Discovery and new insights into cell surface structure and macromolecule transport

Murata

Kawai

Hashimoto

2022

Proceedings of the Japan Academy. Ser. B: Physical and Biologic

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A bacterium with a “mouth”-like pit structure isolated for the first time in the history of microbiology was a Gram-negative rod, containing glycosphingolipids in the cell envelope, and named Sphingomonas sp. strain A1. The pit was dynamic, with repetitive opening and closing during growth on alginate, and directly included alginate concentrated around the pit, particularly by flagellins, an alginate-binding protein localized on the cell surface. Alginate incorporated into the periplasm was subsequently transferred to the cytoplasm by cooperative interactions of periplasmic solute-binding proteins and an ATP-binding cassette transporter in the cytoplasmic membrane. The mechanisms of assembly, functions, and interactions between the above-mentioned molecules were clarified using structural biology. The pit was transplanted into other strains of sphingomonads, and the pitted recombinant cells were effectively applied to the production of bioethanol, bioremediation for dioxin removal, and other tasks. Studies of the function of the pit shed light on the biological significance of cell surface structures and macromolecule transport in bacteria.

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Bacterial System for Alginate Uptake and Degradation

Cited by 4 publications

References 71 publications

The Enzymatic Conversion of Major Algal and Cyanobacterial Carbohydrates to Bioethanol

The Enzymatic Conversion of Major Algal and Cyanobacterial Carbohydrates to Bioethanol

Enzymatic Alginate Modification

Bacteria with a mouth: Discovery and new insights into cell surface structure and macromolecule transport

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