Ultrasonic disruption

Soxhlet extraction Ultrasonic disruption Supercritical fluid extraction Accelerated solvent extraction... 

Enzymes are extracted from cell or tissue by grinding with sea sand, size-controlled glass beads, or aluminium oxide, or by ultrasonic disruption of cell walls. The enzyme first... 

Another use of cell disruption as a step in the analytical process is for obtaining a suspension of single cells — that can be used under optimal fermentation conditions — by ultrasonic disruption of cells manufactured in active dry wine yeast. Their potential was confirmed by comparing the elution profiles of non-sonicated and sonicated yeast sample dispersions obtained using two different field flow fractionation techniques [88]. 

Under the conditions of the assay employed, cellulase activity could not be detected in the supernatant fluid (enzyme fraction 3) of rumen contents. Enzyme fraction 2 which was obtained by ultrasonic disruption of cells in the liquid portion of rumen contents exhibited appreciable activity on CMC but not on Avicel or Solka Floe. On the other hand,... 

One microscale method developed for differential extraction involves a filter-based system and lysis using acoustic energy. The sample is first infused over a filter (size and material not indicated) in which the sperm cells ( 4-6 [tm diameter) pass through unimpeded and the much larger epithelial cells ( 50 [im diameter) are retained. The DNA is then extracted using ultrasonic disruption of the cells. Although it is too early to gauge the success of this method, filtration has been explored on the macroscale for this application without widespread success. 

Hou reported (23) that Flavobacterium sp. DS5 converted oleic acid to 10-KSA in 85% yield. Optimum time, pH, and temperature for the production of 10-KSA are as follows 36 h, 7.5, and 30°C. Asmall amount of 10-HSA( 10% ofthe main product 10-KSA) is also produced during the bioconversion. 10-KSA is not further metabolized by strain DS5 and accumulates in the medium. In contrast to growing cells, a resting cell suspension of strain DS5 produces 10-HSA and 10-KSA in a ratio of 1 3. The cell-free crude extract obtained from ultrasonic disruption of the cells converts oleic acid mainly to 10-HSA (10-HSA 10-KSA = 97 3). This result strongly suggested that oleic acid is converted to 10-KSA via 10-HSA. Stereochemistry of 10-HSA from strain DS5, determined by H NMR ofthe mandelate esters, showed 66% enantiomeric excess in 10(7 ) form. 

Chlorobium vibrioforme f. thiosulfatophilwn strain 8327 was grown photoautotrophically in the medium of Olson et al. (19). Chlorosomes from Cb, vibrioforme were prepared using the chaotropic agent NaSCN to detach them from the membranes of ultrasonically disrupted cells as described by Gerola and Olson (20) for Cb. limicola. 

If the matrix is a biological tissue for which it is desired to disrupt the cells and homogenize the resulting lysate, ultrasonic disruption is widely used, exploiting the cavitation phenomenon discussed in Section 4.3.2c. That earlier discussion was mainly concerned with extracting analytes from slurries of small particles and by implication referred mainly to thermally stable analytes. When... 

Convenient purification of microbially produced transductional protein-based polymers, e.g. poly(GVG T), from the cell lysate is based on a methodologv w hich utilizes the fundamental inverse temperature transitional properties (Urry et al., 1995b McPherson et al, 1996). First the bacterial cells are separated from the growth medium either by centrifugation or filtration and resuspened in Tris-HCl buffer, 50 mM, pH 8.0. Then the cells are lysed by ultrasonic disruption or French press to release the cell contents. The cell lysate is cooled to 4 C and centrifuged at high speed (10,000 x g) to remove the cold insoluble materials. The supernatant... 

An enzyme does not have to be pure to yield valuable information. In many cases simple cell-free preparations containing a mixture of many enzymes may yield most useful results. These preparations are simply made from bacterial cultures in various ways including ultrasonic disruption. For plants resort is commonly made to cell-free preparations from plant tissue cultures [20]. An impressive example is found in recent work on the biosynthesis of terpenoid indole alkaloids (Section 6.6.2). Also to be noted is the application here of radioimmunoassay [21] to the analysis of radioactive alkaloids. 

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