Abstract: A method for aligning reflective surfaces in an unstable laser resonator is provided herein. By providing the outwardly facing side of the front mirror of the resonator with a reflective positioning surface (46) having an optical axis (80) coincident with the optical axis (82) of the front mirror (44), alignment procedures are greatly simplified. The alignment method comprises the steps of fabricating a support surface having a support plate (42) and a front reflective surface (44) on its inner surface, the front reflective surface having a primary optical axis (82). A positioning reflective surface (46) is affixed to an outer surface of the support plate, the positioning reflective surface having a secondary optical axis (80) coincident with the primary optical axis. The support plate also has means for securing the support surface to the laser resonator.

Abstract: A process for greatly improving the yields of cephalosporin nucleus produced by fermentation is described. Cephalosporin C-producing microorganisms are fermented in the presence of an acetylesterase enzyme so that cephalosporin C formed is immediately converted into desacetyl cephalosporin C before any non-enzymic degradation occurs. Fermentation to produce desacetyl cephalosporin C enables yield increases of cephalosporin nucleus of about 40% to be realized, and greater increases are possible if the fermentation is extended. The preferred cephalosporin C-producing organism is Acremonium chrysogenum, and mutants thereof that are capable of producing esterases in situ. Alternatively, esterases obtained from a variety of other sources may be added or formed in situ, for example from a strain of Rhodosporidium.