Parallel Digestion Process

The viscosity of the bleached pulp, among other quality characteristics, constitutes one of the most important control parameters the viscosity value depends, to a great extent, on the cooking process carried out in two continuous digesters working in parallel. 

Figure 5.9 shows a snapshot of an LC CID MS/MS analysis of a tryptic digest of a standard six-protein mixture. The top mass spectrum (scan 1345 in this experiment) is an FT-ICR survey scan. In the subsequent scan ( 1346), CID MS/MS of the precursor ion m/z 524.9 is performed in the linear ion trap. That precursor ion is the most abundant ion in the survey scan that has not been subjected previously to MS/MS, that is, is not on the exclusion list. Scan 1347 is the CID mass spectrum of precursor mJz 6253, the second most abundant ion, not on the exclusion list, in the survey scan. The sequence ends with CID of precursor m/z 707.6, the third most abundant ion, not on the exclusion list, in the survey scan. The subsequent scan (not shown) is an FT-ICR survey scan. An alternative workflow favored by some researchers is one FT-ICR survey MS scan followed by CID in the linear ion trap of the 10 most-abundant ions [107]. These parallel-processing approaches have been applied to a diverse range of studies including analysis of the chicken egg white proteome [108], the low molecular weight proteome of Halobacterium salinarum [109], the endocervical mucas proteome [110], sumoylation in Saccharomyces cerevisiae [111], and the tear fluid proteome [112]. 

Samples are processed in parallel including protein recovery, separation and enzymatic digestion to release peptides... 

The rate of appearance of the difference spectrum is compared to the rate of hydrolysis of the B22-B23 arginyl-glycine bond in Fig. 133. While the curves do not coincide, nevertheless both processes appear to parallel each other. In a separate experiment, carboxypeptidase was used to hydrolyze the B29-B30 lysyl-alanine bond without the development of the difference spectrum. It thus seems that the appearance of the difference spectrum upon tryptic digestion is due to the liberation of the heptapeptide, i.e., to the hydrolysis of the arginyl-glycine, rather than the lysyl-alanine bond. 

The solid output of the mash separation unit has a particle size >10 mm and joins the oversized fraction of the first 80 mm screening step for composting. They are mixed with the solid digestate and with the oversized lignocellulosic fraction originating from a parallel green waste composting process. 

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