Optimization of Escherichia Coli Penicillin G Acylase Production Using Black Liquor a Waste Product of Pulp and Paper Industry

H.V.      Adikane; D.M.      Thakar

Abstract

Aim of the present study was to verify the utility of industrial waste material in the production of an enzyme penicillin G acylase (PGA). Different industrial waste material such as black liquor, molasses, and distillery spent wash were used as a complex organic source (COS) for the production of PGA. Comparatively, black liquor showed higher activity (24±0.8%) and microbial growth (54±1.7%) than the cornsteep liquor a conventional COS. Interestingly, the optimum pH (7.2), temperature (23 °C), and growth time (23 h) obtained for black liquor was similar as obtained for cornsteep liquor. In the presence of peptone, yeast extract and optimized black liquor concentration, 39±1.3% increase in PGA activity (3.97±0.12 U/mg) was observed. The black liquor was stored at 8±2°C and used for the production of PGA for 12 months. The average PGA activity obtained over a period of 12 months was 3.48±0.85 U/mg. The black liquor obtained from different source showed similar PGA activity (3.82±0.15 U/mg). In comparison with uninoculated growth medium, inoculated medium showed 52±1.5% decrease in chemical oxygen demand and 55±1.6%, 59±1.9%, and 91±3.3% decrease in total protein, amino acid and total sugar respectively after 24 h of growth. Comparatively, seven different Escherichia coli strains showed 32±1.5% higher average PGA activity in the presence of black liquor. The utilization of our findings may results in the reduction of overall production cost of PGA and a high value byproduct from waste material to the black liquor generating industries.

Keywords: Black liquor, byproduct, cell growth, chemical oxygen demand, complex organic source, Escherichia coli, industrial waste material, penicillin G acylase.