Hochschule Neubrandenburg, 2009
Abstract: Bacillus subtilis is an attractive host for the production of recombinant proteins. It is capable of secreting functional extracellular proteins directly to the culture medium; it is non-pathogenic; it does not produce any endotoxins; and a great deal of vital information has now been acquired. However, in a position to external stress agents, for example nutrient shortage, Bacillus subtilis is able to develop resistant survival forms, the spores. Spore formation is an unwanted effect while production processes. Aim of this work is to develop a procedure to detect spores as an in- process- control. While spores are resistant to high temperatures, vegetative cells are not. Thus, a detection method for spores based on inactivation of vegetative cells by heating was developed. To determine required conditions to inactivate Bacillus subtilis cells, a Bacillus subtilis strain deficient in spore formation was used. It was shown that cells were efficiently inactivated at 80 °C for 30 minutes whereas spores survived these conditions. Spore formation in a culture of Bacillus subtilis WB800 was determined after 8 h.
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