Optimization of a natural medium for cellulase by a marine Aspergillus niger using response surface methodology.
The components of a natural medium were optimized to produce cellulase from a marine Aspergillus niger under solid state fermentation conditions by response surface methodology. Eichhornia crassipes and natural seawater were used as a major substrate and a source of mineral salts, respectively. Mineral salts of natural seawater could increase cellulase production. Raw corn cob and raw rice straw showed a significant positive effect on cellulase production. The optimum natural medium consisted of 76.9 % E. crassipes (w/w), 8.9 % raw corn cob (w/w), 3.5 % raw rice straw (w/w), 10.7 % raw wheat bran (w/w), and natural seawater (2.33 times the weight of the dry substrates). Incubation for 96 h in the natural medium increased the biomass to the maximum. The cellulase production was 17.80 U/g the dry weight of substrates after incubation for 144 h. The natural medium avoided supplying chemicals and pretreating substrates. It is promising for future practical fermentation of environment-friendly producing cellulase.
Department of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, People's Republic of China.
Dong-Sheng
DS
Xue
Hui-Yin
HY
Chen
Dong-Qiang
DQ
Lin
Yi-Xin
YX
Guan
Shan-Jing
SJ
Yao
D000704:Analysis of Variance; D001234:Aspergillus niger / Q000201:enzymology*; D001709:Biotechnology / Q000379:methods*; D002480:Cellulase / Q000096:biosynthesis*; D003470:Culture Media / Q000494:pharmacology*; D031806:Eichhornia / Q000187:drug effects / Q000378:metabolism; D005285:Fermentation / Q000187:drug effects; D008903:Minerals / Q000494:pharmacology; D008954:Models, Biological; D012275:Oryza / Q000187:drug effects / Q000378:metabolism; D012623:Seawater / Q000382:microbiology*; D013997:Time Factors; D014908:Triticum / Q000187:drug effects / Q000378:metabolism; D014867:Water / Q000494:pharmacology; D003313:Zea mays / Q000187:drug effects / Q000378:metabolism
D003470:Culture Media; D008903:Minerals; D014867:Water; D002480:Cellulase