Production of polyhydroxybutyrate from wheat bran hydrolysate using Ralstonia eutropha through microbial fermentation.
The increasing global demand for sustainable resources necessitates the complete utilization of feedstock. Wheat bran consists of significant amount of cellulose and hemicellulose which can be used as a renewable resource for production of fermentable sugars. In this study, alkaline pretreated wheat bran was enzymatically hydrolyzed using cellulase of Trichoderma reesei (37 FPU/g) and β - glucosidase of Aspergillus niger (50 CBU/g). Among the nitrogen sources tested, ammonium sulphate was identified as best nitrogen source for the production of polyhydroxybutyrate (PHB). The overall sugar concentration was about 62.91g/L with the corresponding sugar yield of 629.1mg/g wheat bran and the sugars released were mainly composed of glucose (48.35g/L) and xylose (14.56g/L). The PHB producing mutant strain, Ralstonia eutropha NCIMB 11599 grown in wheat bran hydrolysate produced cell density, PHB and yield of 24.5g/L, 62.5%, and 0.319g/g sugar respectively, with a productivity of 0. 0.255g/L/h. Thus, the results suggested that the wheat bran could be a potential alternative feedstock as it does not require any detoxification due to less inhibitory compounds for production of high cell density with significant amount of polyhydroxybutyrate.
Hawaii Natural Energy Institute, University of Hawaii at Manoa, 1680, East-west Road, Honolulu, 96822, HI, USA; Department of Biology, College of Science, Sultan Qaboos University, PO Box 36, PC 123, Muscat, Oman. Electronic address: annabact@gmail.com.
Neelamegam
N
Annamalai
Department of Biology, College of Science, Sultan Qaboos University, PO Box 36, PC 123, Muscat, Oman.
Nallusamy
N
Sivakumar
D001234:Aspergillus niger / Q000201:enzymology; D050260:Carbohydrate Metabolism; D002480:Cellulase / Q000378:metabolism; D002482:Cellulose / Q000378:metabolism; D020118:Cupriavidus necator / Q000378:metabolism*; D004043:Dietary Fiber / Q000378:metabolism*; D005285:Fermentation; D006868:Hydrolysis; D006885:Hydroxybutyrates / Q000378:metabolism*; D009154:Mutation; D011134:Polysaccharides / Q000378:metabolism; D014242:Trichoderma / Q000201:enzymology; D001617:beta-Glucosidase / Q000378:metabolism
D004043:Dietary Fiber; D006885:Hydroxybutyrates; D011134:Polysaccharides; C007916:hemicellulose; D002482:Cellulose; D001617:beta-Glucosidase; D002480:Cellulase
Enzymatic hydrolysis; Lignocellulosic biomass; Polyhydroxybutyrate; Ralstonia eutropha; Wheat bran