Abstract
A mass spectrometrically identified biomarker, possibly “cold shock protein” by database homologous searching, can be helpful to classify two genus of actinomycetes, Microbispora and Dactysporangium. To further characterize cold shock proteins, we amplified the gene of a cold shock from another genus of actinomycetes, S. coelicolor and make specific antibody against it. Cells were maintained at low temperature for 0~24 h, cold shock proteins and their mRNAs isolated from S.coelicolor, D. fusco-aurantiacum and M. amethystogenes were monitored by Western and Northern blot. The finding suggested cold shock proteins didn’t change as much as expected. Nevertheless, their mRNAs increased abruptly upon temperature downshift (cold shock after 1 h), started to decrease after 2 h and finally disappeared at 24 h. However, findings of MALDI-LTOF mass analysis of these strains were not analogous to our expected results. The m/z values of their cold shock proteins were different from that found by a previous report. Therefore, whether cold shock protein is suitable to be a biomarker in mass analysis for actinomycetes classification should be further evaluated. We should improve the mass spectrometric reproducibility by strictly establishing more standardized actinomysetes culture condition.