Improved mannan-degrading enzymes' production by Aspergillus niger through medium optimization.
The effect of different carbon and nitrogen sources on the production of mannan-degrading enzymes, focussing on β-mannanase, by Aspergillus niger was investigated using shake flask culture. The β-mannanase activity obtained during growth of A. niger on guar gum (GG, 1495 nkat mL(-1)) was much higher than those observed on other carbon substrates, locust bean gum (1148 nkat mL(-1)), α-cellulose (10.7 nkat mL(-1)), glucose (8.8 nkat mL(-1)) and carboxymethylcellulose (4.6 nkat mL(-1)). For fermentation using GG as a carbon source, bacteriological peptone gave the highest β-mannanase activity (1744 nkat mL(-1)) followed by peptone from meat (1168 nkat mL(-1)), yeast extract (817 nkat mL(-1)), ammonium sulphate (241 nkat mL(-1)), ammonium nitrate (113 nkat mL(-1)) and ammonium chloride (99 nkat mL(-1)) when used as a nitrogen source. The composition of bacteriological peptone and initial pH of the medium were further optimized using response surface methodology (RSM). Medium consisted of 21.3 g L(-1) GG and 57 g L(-1) peptone with initial culture pH of 5.5 was optimum for β-mannanase production (2063 nkat mL(-1)) by A. niger. The β-mannanase production obtained in this study using A. niger was significantly higher than those reported in the literature.
Freshwater Fisheries Research Centre, 75350 Batu Berendam, Malacca, Malaysia.
Siti Norita
SN
Mohamad
Ramakrishnan Nagasundara
RN
Ramanan
Rosfarizan
R
Mohamad
Arbakariya B
AB
Ariff
D001234:Aspergillus niger / Q000201:enzymology*; D002244:Carbon / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D008351:Mannans / Q000378:metabolism*; D009584:Nitrogen / Q000378:metabolism; D044902:beta-Mannosidase / Q000096:biosynthesis*
D008351:Mannans; D002244:Carbon; D044902:beta-Mannosidase; D009584:Nitrogen