Metal hydroxide
Metal hydroxides are also known as strong bases. Many common metal hydroxides are made up from hydroxide ions and the ion of the particular metal that it is made up of. Example: When NaOH (sodium hydroxide) is dissolved in water, it forms OH ions and Na ions. Metal hydroxides ionize completely when dissolved, so that is why they are known as strong bases. Their pH is above 7, labeling them as bases. Since ions conduct electricity, metal hydroxides carry electricity very well when they are dissolved.In soils, it is assumed that larger amounts of natural phenols are released from decomposing plant litter rather than from throughfall in any natural plant community. Decomposition of dead plant material causes complex organic compounds to be slowly oxidized (lignin-like humus) or to break down into simpler forms (sugars and amino sugars, aliphatic and phenolic organic acids), which are further transformed into microbial biomass (microbial humus) or are reorganized, and further oxidized, into humic assemblages (fulvic and humic acids), which bind to clay minerals and metal hydroxides.
Oxidase test
The oxidase test is a test used in microbiology to determine if a bacterium produces certain cytochrome c oxidases. It uses disks impregnated with a reagent such as "N,N,N′,N′"-tetramethyl-"p"-phenylenediamine (TMPD) or "N,N"-dimethyl-"p"-phenylenediamine (DMPD), which is also a redox indicator. The reagent is a dark-blue to maroon color when oxidized, and colorless when reduced. Oxidase-positive bacteria possess cytochrome oxidase or indophenol oxidase (an iron-containing
hemoprotein). These both catalyze the transport of electrons from donor compounds (NADH) to
electron acceptors (usually oxygen).
The test reagent, TMPD dihydrochloride acts as an artificial electron donor for the enzyme oxidase. The oxidized reagent forms the colored compound indophenol blue.
The cytochrome system is usually only present in aerobic organisms that are capable of using oxygen as the terminal electron acceptor. The end-product of this metabolism is either water or hydrogen peroxide (broken down by catalase).