Effect of electron acceptor conditions on hydrolytic enzyme synthesis in bacterial cultures

An experimental study was undertaken to observe the effect of electron acceptor conditions on the enzyme synthesis potential in pure cultures of Bacillus amyloliquefaciens (gram positive) and Pseudomonas saccharophilia (gram negative). An appropriate experimental methodology was developed to observe enzymes synthesis over a time period by using enzyme assay technique. It was found that the development of the starch hydrolytic enzyme system in both the cultures was strongly affected by the type of electron acceptor conditions. The relative change in the enzyme synthesis due to change in electron acceptor conditions was more pronounced in B. amyloliquefaciens as compared to P. saccharophilia. In case of B. amyloliquefaciens the calculated reduction factors eta(no3) and eta(fe) ranged from 0.13 to 0.21 and 0.04 to 0.06, respectively, whereas for P. saccharophila they were found to range from 0.40 to 0.54 and 0.20 to 0.27, respectively. An apparent relationship between the growth rates of the cultures during active growth phase in minimal starch medium and their specific enzyme synthesis potential was observed. Further, the hydrolytic enzymes were found to be released in the bulk solution and the activity of the synthesized enzymes was found to be independent of electron acceptor conditions. (C) 1997 Elsevier Science Ltd.