Cell walls ball-milling

Extraction of proteia requires breaking the cell wall to release the cytoplasmic contents. This can be achieved by high speed ball or coUoid mills or by high pressure (50—60 Mpa) extmsion. Proteia is extracted by alkaline treatment followed by precipitation after enzymatic hydrolysis of nucleic acids. Although the proteia can be spun iato fibers or texturized, such products are more expensive than those derived from soybean and there is no market for them. 

Lu, F. Ralph, J. Non-degradative dissolution and acetylation of ball-milled plant cell walls high-resolution solution-state NMR. Plant J. 2003, 35, 535-544. 

Ball mills are best suited for breaking up strong cell walls such as those encountered in Gram-positive bacteria, but scale-up is limited beyond the small pilot scale. French presses are the apparatus of choice for large-scale homogenization of cells. 

A relatively recent development, aided by the high sensitivity of modern NMR instruments equipped with cryogenic probes, is to obtain lignin data from spectra run on the entire cell wall component i.e., without lignin fractionation/isolation [61,64,98,100], Ball-milled cell walls can be dissolved or simply swelled in various solvents to yield strikingly high quality spectra [102,103],... 

Kim, H., and Ralph, J. (2009) Solution-state 2D NMR of ball-milled plant cell wall gels in DMSO-d6/pyridine-d5. Org. Biomol. Chem. 8(3), 576-591. 

From this it is inferred that the cell wall polymers are unlikely to be degraded under the conditions used in our studies. However, when dry ball-milling is substituted, the cell wall preparations are reduced after 45 h to overall particle size of 5 —15 p-m. Therefore dry ball-milling may cause some degradation of cell wall polymers, and for this reason it is avoided. 

Most methods for LCC isolation from wood require ball milling, which is carried out so that the cell wall matrix can be degraded and the lignin and LCC fragments can be released and extracted. Extraction of the milled wood with 96% dioxane produces crude milled wood lignin (MWLc) [24]. 

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