Optimization of production and reaction conditions of polygalacturonase from Byssochlamys fulva.
In the present study, the optimization of production and reaction conditions of polygalacturonase produced by a fungus Byssochlamys fulva MTCC 505 was achieved. The production of polygalacturonase with a considerable activity of 1.28 IU/ml was found when the culture was shaken at 30°C for 5 days in 100 ml of medium containing (w/v) 10 g/l pectin, 2 g/l NaNO₃, 1 g/l KH₂PO₄, 0.5 g/l KCl, 0.5 g/l MgSO₄. 7H₂O, 0.001 g/l FeSO₄. 7H₂O, 0.001 g/l CaCl₂. The best carbon and nitrogen source for this enzyme were pectin (1%) and Ca(NO₃)₂ (0.1%), respectively. The enzyme gave maximum activity at incubation time of 72 h, temperature of 30°C and pH 4.5. During the optimization of reaction conditions, the enzyme showed maximum activity in sodium citrate buffer (50 mM) of pH 5.5 at 50°C reaction temperature for 15 minutes of incubation. The enzyme showed greater affinity for polygalacturonic acid as substrate (0.5%). Km and Vmax values were 0.15 mg/ml and 4.58 μmol/ml/min. The effect of various phenolics, thiols, protein inhibitors and metal ions on the enzyme activity was investigated. The enzyme was quite stable at 4°C and 30°C. At 40°C the half life of the enzyme was 6 h and at 60°C it was 2 h.
Department of Biotechnology, Himachal Pradesh University, Summer Hill, Shimla 171005 India. reenagupta_2001@yahoo.com
Reena
R
Gupta
Kalpana
D055323:Byssochlamys / Q000201:enzymology* / Q000254:growth & development; D006863:Hydrogen-Ion Concentration; D011096:Polygalacturonase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D013696:Temperature
D011096:Polygalacturonase