Production and Further Characterization of an Alkaline Elastase Produced by Alkalophilic Bacillus Strain Ya-B

Abstract

The characteristics of the obligate alkalophilic Bacillus sp. strain Ya-B, which produces alkaline elastase extracellularly, were examined. This strain grew at pH 7.0 only in the presence of 1% or more NaCl. Its fatty acid distribution pattern was similar to that of other Bacillus species in which iso-C15 and anteiso-Cl5 were the most abundant fatty acids. About 120 mg of enzyme was recovered from 1 liter of culture broth in a medium (pH 10.1) containing mainly glucose, soymeal, and glycerol. The antiserum against this enzyme did not recognize microbial proteinases, such as subtilisins, but reacted with proteinase C, which was purified from commercial pronase. Chemical modification studies revealed that certain histidine and tyrosine residues might be involved in the enzyme activity. This enzyme underwent a partial unfolding at pHs higher than 12.0, as indicated by the circular dichroism study.

Inhibition of Aspergillus fumigatus elastase with monoclonal antibodies produced by using denatured elastase as an immunogen

“…A number of possibilities might explain these earlier results. Elastases, which are found in many organisms, including mammals (4,16,22,38,46), bacteria (19,25,50,51), schistosomes (23, 24), and fungi (18,27,34), may be conserved structurally and thus be essentially weak immunogens (52). If the native fungal elastase is structurally similar to murine elastase, then it may not be sufficiently foreign to induce a vigorous immune response.…”

Versatility of microbial proteases

“…However, in the case of B. subtilis ATCC strain 14416 [85] and B. sphaericusstrain BSE 18 [86], enzyme production was growth-associated and it occurs at the mid-exponential phase, and often a rapid auto deactivation process was observed after the culture reached the maximum enzyme activity. During alkaline protease production, it was also observed that the pH of the fermented medium dropped from alkaline to acidic; for instance, from pH 10.1 to 8.5 in the case of an alkalophilic Bacillus strain Ya-B [87].…”

Enhanced production of elastase by Bacillus licheniformis ZJUEL31410: optimization of cultivation conditions using response surface methodology

“…The low activity of elastase produced by microorganisms has greatly hampered the research on the role of microbial elastases, and only a few attempts have been made to increase elastase productivity by manipulating physiological conditions and medium compositions (Tsai et al, 1988;Chen et al, 2002). Some recent studies in the field of the optimization of fermentation conditions have reported a significant increase in the yields of elastase (Chen et al, 2002;He et al, 2004).…”

“…In recent years, some researchers have found that although many Gram-negative and -positive bacteria secrete elastase, the bacterial forms of elastase either have a low activity or harmful effects so that few of them are of medical or industrial values (Tsuzuki and Oka, 1965;Ozaki and Shiio, 1975;Clark et al, 2000;Janda and Abbott, 1999). Others have exerted their efforts in isolating and screening microorganisms that produce a high level of elastase (Shibata et al, 1993;Tsai et al, 1988;Zins et al, 2001).…”

“…Although considerable efforts have been made to screen the elastase-producing bacterial strains in studying its pathogenic effects and characterizations (Tsai et al, 1988;Shibata et al, 1993;Zins et al, 2001), few studies focusing on bacterial fermentation, especially culture medium optimization and fermentation kinetics, have been reported. In the previous study (Chen et al, 2002) we have described an optimal cultivation medium.…”