Assignment of the chicken tyrosine hydroxylase gene to chromosome 6 by FISH.

The gene for tyrosine hydroxylase, the first and rate-limiting enzyme in the biosynthetic pathway of catecholamine neurotransmitters, has been localized in situ to chromosome 6 in the chicken. It is the first DNA marker to be reported for this telocentric macrochromosome. Use of a 45-kb biotinylated chicken-specific cosmid probe and a sensitive fluorescent detection system proved to be highly efficient, with over 90% of metaphases showing positive hybridization signals on one or (usually) both chromosome 6 homologs, in physically mapping this single-gene locus.     

Influence of several perturbants on the rate of autoxidation of horse heart ferrocytochrome c

The effect of several different types of perturbants and pH on the rate of autoxidation of horse heart ferrocytochrome c was investigated. The kinetic behavior is unique to each perturbant used. Rates of autoxidation followed first-order kinetics over the time span (0-180 min) studied. The Cl- and Br- anions exhibit an initial increase in the rate of autoxidation up to 100 mM, followed by a decrease in kinetics at 500 mM anion concentration. The ClO4- anion exhibits only an increase in the rate of autoxidation with increasing ionic strength, where as, propylurea, a hydrophobic perturbant, is not effective in altering the rate of autoxidation at equivalent concentrations. These studies suggest that the perturbations of the reduced form of cytochrome c in solution involve mainly non-specific solvent effects.     

Pretreatments for Enhanced Enzymatic Hydrolysis of Pinewood: a Review

Pinewood is an abundant source of lignocellulosic biomass that has potential to be used as renewable feedstock in biorefineries for conversion into advanced biofuels and other value-added chemicals. However, its structural recalcitrance, due to the compact packing of its major components, viz. cellulose, hemicellulose and lignin, high lignin content, and high cellulose crystallinity, is a major bottleneck in its widespread use as a biorefinery feedstock. Typical chemical, thermal, and biological pretreatment technologies are aimed at removing lignin and hemicellulose fractions for improving enzyme accessibility and digestibility of cellulose. This review highlights common pine pretreatment procedures, associated key parameters and resulting enzymatic hydrolysis yields. The challenges and limitations are also discussed as well as potential strategies to overcome them, providing an essential source of information to realize pine as a compelling biorefinery biomass source.