The Influence of Glucose, Ammonium and Magnesium Availability on the Production of Protease and Bacitracin by Bacillus licheniformis

Abstract

Bacillus licheniformis was cultivated in a range of defined media varying in both the nature of the growth-limiting component and the concentration of excess nutrients. The compositions of the media were such as to ensure that the final absorbance (A430) of the culture was the same in each case. Samples taken during the stationary phase were assayed for their content of extracellular serine protease and bacitracin. The nature of the growth-limiting nutrient had a profound effect on the amounts of these products formed while those components which were present in excess also exerted an influence in proportion to their concentration. Thus, for example, a four-fold increase in serine protease production occurred when ammonium replaced glucose as the growth-limiting nutrient. Serine protease and bacitracin production responded differently to these varying cultural conditions suggesting they are subject to separate control mechanisms. The results are discussed in relation to the need for rigorously controlled cultural conditions during physiological studies of this nature.

Purification and Characterization of a Psychrophilic, Calcium-Induced, Growth-Phase-Dependent Metalloprotease from the Fish Pathogen Flavobacterium psychrophilum

“…Extracellular proteases have been shown to be sensitive to repression by different carbohydrate and nitrogen sources (22,32). Additionally, in many cases expression of virulence factors is dependent on a single environmental factor, whereas in other cases virulence factors are coordinately regulated and their expression is mediated by a combination of two or more signals (for reviews, see references 18 and 41).…”

TheyrpABoperon ofYersinia ruckeriencoding two putative U32 peptidases is involved in virulence and induced under microaerobic conditions

“…Generally, most bacterial proteases are negatively regulated by glucose and ammonium, 25,26 and as one would expect, the Yrp1 protease of Y. ruckeri was also repressed by these compounds. 27 The fact that they had no effect on the yrpAB operon activity indicates that it is not under a regulation system similar to that of other bacterial proteases and suggests that it could play an additional function apart from a nutritional one, or even have a specific role during the infection process.…”

Variations in structural and plasmid profiles of starved Shigella in seawater

“…The effect of environmental conditions on the production of extracellular proteolytic enzymes could play an important role in the induction or repression of the enzyme by specific compounds (Secades and Guijarro, 1999). Production of extracellular proteases has been shown to be sensitive to repression by different carbohydrate and nitrogen sources (Haulon et al, 1982). Catabolic enzymes responded to both carbon control and nitrogen control in enteric bacteria (Goldberg et al, 1976).…”