Bioconversion of waste office paper to gluconic acid in a turbine blade reactor by the filamentous fungus Aspergillus niger.
Gluconic acid production was investigated using an enzymatic hydrolysate of waste office automation paper in a culture of Aspergillus niger. In repeated batch cultures using flasks, saccharified solution medium (SM) did not show any inhibitory effects on gluconic acid production compared to glucose medium (GM). The average gluconic acid yields were 92% (SM) and 80% (GM). In repeated batch cultures using SM in a turbine blade reactor (TBR), the gluconic acid yields were 60% (SM) and 67% (GM) with 80-100 g/l of gluconic acid. When pure oxygen was supplied the production rate increased to four times higher than when supplying air. Remarkable differences in the morphology of A. niger and dry cell weight between SM and GM were observed. The difference in morphology may have caused a reduction of oxygen transfer, resulting in a decrease in gluconic acid production rate in SM.
Laboratory of Biotechnology, Department of Applied Biological Chemistry, Faculty of Agriculture, Shizuoka University, 836 Ohya, Shizuoka 422-8529, Japan.
Yuko
Y
Ikeda
Enock Y
EY
Park
Naoyuki
N
Okuda
D000388:Air; D001234:Aspergillus niger / Q000166:cytology / Q000254:growth & development / Q000378:metabolism* / Q000648:ultrastructure; D018533:Biomass; D019149:Bioreactors / Q000382:microbiology*; D001709:Biotechnology / Q000379:methods*; D002119:Calcium Carbonate / Q000378:metabolism; D002125:Calcium Gluconate / Q000378:metabolism; D002482:Cellulose / Q000378:metabolism / Q000648:ultrastructure; D003470:Culture Media / Q000737:chemistry; D005942:Gluconates / Q000378:metabolism*; D005947:Glucose / Q000378:metabolism; D006868:Hydrolysis; D010100:Oxygen / Q000378:metabolism; D010209:Paper; D012037:Refuse Disposal / Q000379:methods; D012996:Solutions; D013395:Sucrose / Q000378:metabolism; D013997:Time Factors
D003470:Culture Media; D005942:Gluconates; D012996:Solutions; D013395:Sucrose; D002482:Cellulose; D002119:Calcium Carbonate; D005947:Glucose; C030691:gluconic acid; D010100:Oxygen; D002125:Calcium Gluconate