Extracellular Enzymes of Bacillus licheniformis from Milkfish Gut as Degradation Agent of Chlorella vulgaris Cell Wall

Bacillus licheniformis from milkfish gut (Chanos chanos) has been known to have cellulolytic ability and is expected to be used as Chlorella cell walls degradation agent to produce Single-cell proteins. Other abilities and characteristics of extracellular enzymes from Bacillus licheniformis are still unknown. Detection of the extracellular enzymes from Bacillus licheniformis was carried out by observing the presence of clear zones surrounding the colonies on selective mediums and measured using spectrophotometric techniques. The measurement of cellulase and hemicellulase activities was carried out by the DNS method. The optimal pH and temperature of cellulase and hemicellulase activities have also been determined. Chlorella cell wall degradation test was carried out by applying the enzyme on cell and observed under the inverter microscope. We found that the best incubation time for Bacillus licheniformis in producing cellulase and hemicellulase is 48 h and 72 h respectively with enzymes activities of 6.016 U/ ml and 2.482 U/ml respectively. The optimum pH and temperature for cellulase and hemicellulase activities were pH 7 and pH 6 and 29 degrees C and 37 degrees C. This research is a step towards the production of single cell proteins using alternative enzymes.

Automated summary

Bacillus licheniformis from milkfish gut has cellulolytic ability and can potentially be used as a Chlorella cell walls degradation agent for the production of Single-cell proteins. This research identified optimal conditions for the activities of cellulase and hemicellulase enzymes, laying a foundation for the production of single cell proteins using alternative enzymes.