The use of alpha-galactosidase and invertase in hollow fiber reactors

Invertase and alpha-galactosidase have been immobilized in hollow fiber cartridges with no detectable enzyme leakage and used for the hydrolysis of sucrose and raffinose, respectively. For both hollow fiber immobilized enzymes nearly complete substrate conversion is possible. Enzyme stabilities in polysulfonate hollow fibers which have been preconditioned with bovine albumin approach the stabilities of the free enzymes.

DNA replication in Chinese hamster ovary cells made permeable to nucleotides by tween-80 treatment

We have developed a method for permeabilizing CHO cells to nucleotides under conditions which allow most cells to remain viable. Permeabilized cells can carry out ATP-dependent, semiconservative synthesis of DNA. The data are consistent with the continuation of DNA synthesis in those cells in S phase at the time of treatment, possibly limited to completion of replicon synthesis without new initiations.

Hydrogen production in the rat following ingestion of raffinose, stachyose and oligosaccharide-free bean residue

Raffinose and stachyose were compared to cooked California Small White beans (CSW) containing 4% alpha-oligosaccharides (stachyose and raffinose) and to oligosaccharide-free CSW solids (residue from hexane and 70% ethanol extraction of CSW) as sources of hydrogen when ingested by rats maintained in life support systems. If the oligosaccharide content were the only hydrogen source in CSW, it would have had to be 25 times as potent as CSW, but raffinose was only five times and stachyose seven times as potent as CSW. Oligosaccharide-free residue was 0.4 to 0.5 as active as CSW. Hydrogen producing potencies of stachyose and raffinose were enhanced by feeding in combinations with residue. The increases in hydrogen production from the combinations were more than additive. Thus, CSW contains at least one 70% alcohol-insoluble substance which, in addition to the oligosaccharides, is essential to bring about quantitatively the physiological response to whole beans observed in rats.

Plant suspension culture media macromolecules-pectic substances, protein, and peroxidase

Macromolecules secreted into the media by a nondifferentiating suspension culture of tobacco cells were found to be composed of protein and polysaccharide, and to account for the viscosity of the media. The concentration, composition, and viscosity of these macromolecules changed significantly with the age of the culture and growth temperature. The concentration changed from 0.02 mg/ml in newly inoculated cultures to over 1 mg/ml in older cultures. The macromolecules contained from 6 to 18% protein and 3 to 4 mumoles hydroxy-proline/mg nitrogen, more than 20 times the level found in whole cells. The macromolecules contained 5 to 25% pectic substances whose carboxyl groups were either methyl esterified or combined with calcium. Arabinose, xylose, glucose, galactose, and mannose were identified in acid hydrolysates of the macromolecules. Peroxidase activity of the macromolecules increased as cultures became older. Peroxidase isoenzyme patterns changed with culture age and growth temperature. The relation of the macromolecules to cell walls and intercellular substances is discussed.

Glutaraldehyde activation of nuclear acid phosphatase in cultured plant cells

Cultured tobacco cells exhibited a nuclear reaction in the cytochemical test for acid phosphatase after exposure to 2 percent glutaraldehyde. A slight preference for adenosine monophosphate over beta glycerophosphate as substrate was noted, but the enzymatic activity was not typically 5' nucleotidase. Other aldehydes tested did not elicit the same enzyme response. Nucleolar localization was distinct from that in the rest of the nucleus. Assay for spectrophotometric measurements of enzymatic activity in vitro was developed as a modification of the Burstone procedure with naphthol AS-B1 phosphate and diazo blue B.