Cellulose nucleotide precursors

A variety of powerful methods is available for fractionating short oligonucleotides. Work on nucleotide sequence analysis of small RNA molecules (n=80 or 120) and more recently viral RNA molecules (n= 3000) and even ribosomal precursor RNAs (up to 45 s) (Holley et al. 1965a Brownlee 1972 Maden et al. 1972) has stimulated the development of these procedures. They can also be used for synthetic oligonucleotides (e.g. Hachman and Khorana, 1969). The methods depend largely on chromatography and electrophoresis on filter papers, diethylaminoethyl(DEAE) paper, cellulose acetate, thin layers of cellulose or polyethyleneimine (PEI)-cellulose, or columns. 

In 1953, Bemheimer demonstrated that washed, resting cells from Type III Pneumococcus could synthesize Sill in the presence of D-glucose or certain other monosaccharides, Mg , K , P04 , and oxygen. Biosynthesis of the capsular polysaccharides was shown later to depend on the presence of uridine nucleotides. Similar precursors have been implicated in the biosynthesis of cellulose, chitin, /3-d-(1—>3)-glucan, glycogen, and hyaluronic acid. ... 

Both starch and cellulose are prepared in nature by enzymatic, chain growth polymerization reactions of glucose nucleotide monomers [6]. In both cases, the monomer precursor is glucose-1-phosphate, which is enzymatically converted to the nucleotide derivative. The latter, in turn, complexes with an enzyme to form the activated monomer at the active site on the enzyme, which also contains the growing polymer molecule, as schematically illustrated below for the enzymatic polymerization of cellulose ... 

The cell as a biosynthesis machine can use cheap carbon sources (waste products) as precursor substrates to produce bacterial polymers. However, the in vitro synthesis of biopolymers requires costly purified key enzymes and precursor molecules such as ATP, coal, coal bolsters, and nucleotide sugars or sugar acids to synthesize polymers such as PHA, cellulose, alginate, and PGA. Consequently, these polymers have limited commercial applicability due to their very high production costs. It is estimated the production of PHB by in vitro synthesis would amount to a cost of around US 286,000 per gram of PHB whereas, bacterial production of PHB was estimated to cost about 0.0025 per gram of PHB, and this is still 5-10 times as expensive to produce as the respective petroleum-based polymers. 

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