RESPONSE OF BACTERIA AND FUNGI TO HIGH-PRESSURE STRESS AS INVESTIGATED BY 2-DIMENSIONAL POLYACRYLAMIDE-GEL ELECTROPHORESIS

In an attempt to generalize previous observations (Jaenicke et al., Ap pl. Environ. Microbiol. 1988, 54, 2375-2380) and to find a convenient model system for studies of the pressure response, we tested the suita bility of Escherichia coli and Thermotoga maritima (bacteria), and of five different eukaryotic species including the filamentous fungi Aste romyces cruciatus and Dendryphiella salina, and the marine yeasts Deba ryomyces hansenii, Rhodosporidium sphaerocarpum, and Rhodotorula rubra . Using two-dimensional polyacrylamide gel electrophoresis, detailed i nvestigations on the pressure response were carried out with E. coli a nd Rhodosporidium sphaerocarpum. In the former organism, major pressur e response proteins could not be detected, although there are signific ant differences in expression of some proteins as well as some minor c omponents that are found in all of the high pressure cell extracts but not in extracts from cultures grown at atmospheric pressure. In Rhodo sporidium sphaerocarpum, no change in protein expression patterns was observed between 0.1 and 20 MPa. However, approaching the limit of via bility of 50 MPa, additional protein spots became detectable at 45 MPa . This finding correlates with the observation of abnormal growth form s of the organism at this pressure (Lorenz, R. ef al, manuscript in pr eparation).