SPECTROPHOTOMETRIC ANALYSIS OF YEASTS: CYTOCHROME SPECTRA OF SOME Q₇ PICHIA

Abstract

Whole-cell pastes of Pichia, equipped with the coenzyme Q₇, were spectrophotometrically analyzed (38 species). The low-temperature absorption cytochrome spectra showed a great diversity of response. The typical α₁ peak of cytochrome c (545-546.5nm) might be complemented in a few species by a less pronounced α₂ peak (544-545nm). The cytochrome oxidase peak (a+a3) was rarely typical and symmetric and showed two noticeable peculiarities: -an unsymmetrical peak with the main absorption range from 597.5 to 602.5nm and a shoulder at the lower or upper wavelength, and a double peak of cytochrome oxydase (596-598.5nm)-(605-607nm) or (593-594nm)-(601-602nm) rarely seen elsewhere in the yeasts.
These characteristics, associated with GC contents, led to the identification of 3 main groups in the genus Pichia concerning at least 35 species.