Back to Search
Start Over
Production of poly-γ-glutamic acid (γ-PGA) from xylose-glucose mixtures by Bacillus amyloliquefaciens C1
- Source :
- 3 Biotech. 11
- Publication Year :
- 2021
- Publisher :
- Springer Science and Business Media LLC, 2021.
-
Abstract
- Due to the promising applications, the demand to enhance poly-γ-glutamic acid (γ-PGA) production while decreasing the cost has increased in the past decade. Here, xylose/glucose mixture and corncob hydrolysate (CCH) was evaluated as alternatives for γ-PGA production by Bacillus amyloliquefaciens C1. Although both have been validated to support cell growth, glucose and xylose were not simutaneously consumed and exhibited a diauxic growth pattern due to carbon catabolite repression (CCR) in B. amyloliquefaciens C1, while the enhanced transcription of araE alleviated the xylose transport bottleneck across a cellular membrane. Additionally, the xyl operon (xylA and xylB), which was responsible for xylose metabolism, was strongly induced by xylose at the transcriptional level. When cultured in a mixed medium, xylR was sharply induced to 3.39-folds during the first 8-h while reduced to the base level similar to that in xylose medium. Finally, pre-treated CCH mainly contained a mixture of glucose and xylose was employed for γ-PGA fermentation, which obtained a final concentration of 6.56 ± 0.27 g/L. Although the glucose utilization rate (84.91 ± 1.81%) was lower than that with chemical substrates, the xylose utilization rate (43.41 ± 2.14%) and the sodium glutamate conversion rate (77.22%) of CCH were acceptable. Our study provided a promising approach for the green production of γ-PGA from lignocellulosic biomass and circumvent excessive non-food usage of glucose.
- Subjects :
- Bacillus amyloliquefaciens
biology
Chemistry
Catabolite repression
Lignocellulosic biomass
Environmental Science (miscellaneous)
Xylose
biology.organism_classification
Agricultural and Biological Sciences (miscellaneous)
Hydrolysate
Diauxic growth
chemistry.chemical_compound
Xylose metabolism
Fermentation
Food science
Biotechnology
Subjects
Details
- ISSN :
- 21905738 and 2190572X
- Volume :
- 11
- Database :
- OpenAIRE
- Journal :
- 3 Biotech
- Accession number :
- edsair.doi...........842b1a60a5e622160ccfdd30b6934f11