Enhanced Bacillus cereus BG1 protease production by the use of sardinelle (Sardinella aurita) powder

Abstract

The present study is concerned with the selection of a new economical medium for growth and production of a calcium-dependent protease by Bacillus cereus BG1 strain.Various fish powders were prepared from sardinelle (Sardinella aurita) and then tested for the growth and the production of protease by Bacillus cereus BG1 strain: whole sardinelle powder (WSP), meat sardinelle powder (MSP) and combined heads and viscera sardinelle powder (CHVSP). Protease synthesis was significantly low when the strain was grown in media containing only fish powders. However, the addition of Ca2+ to the fish media enhanced the production of protease. Maximum activity was obtained on CHVSP followed by WSP. Other metal ions, such as Mg2+, Mn2+ and Ba2+, were also found to enhance protease production. However, in media containing maltose as carbon source and ammonium sulfate as nitrogen source, protease activity was detected only when media were supplemented with CaCl2.These results clearly indicated that the utilization of fish powders, in particular that produced from sardinelle by-products, may result in a cost-effective process suitable for large-scale production of proteases. © Springer-Verlag and the University of Milan 2010.