The simultaneous consumption of glucose and glycerol led to remarkably higher productivity of both biomass and ε-poly-L-lysine (ε-PL), which was of great significance in industrial microbial fermentation. To further understand the superior fermentation performances, transcriptional analysis and exogenous substrates addition were carried out to study the simultaneous utilization of glucose and glycerol by Streptomyces albulus M-Z18. Transcriptome analysis revealed that there was no mutual transcriptional suppression between the utilization of glucose and glycerol, which was quite different from typical "glucose effect". In addition, microorganisms cultivated with single glycerol showed significant demand for ribose-5-phosphate, which resulted in potential demand for glucose and xylitol. The above demand could be relieved by glucose (in the mixed carbon source) or xylitol addition, leading to improvement of biomass production. It indicated that glucose in the mixed carbon source was more important for biomass production. Besides, transcriptional analysis and exogenous citrate addition proved that single carbon sources could not afford enough carbon skeletons for Embden Meyerhof pathway (EMP) while a glucose-glycerol combination could provided sufficient carbon skeletons to saturate the metabolic capability of EMP, which contributed to the replenishment of precursors and energy consumed in ε-PL production. This study offered insight into the simultaneous consumption of glucose and glycerol in the ε-PL batch fermentation, which deepened our comprehension on the high ε-PL productivity in the mixed carbon source.

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00449-017-1832-9DOI Listing

Publication Analysis

Top Keywords

glucose glycerol
20
utilization glucose
12
mixed carbon
12
carbon source
12
simultaneous utilization
8
glucose
8
glycerol streptomyces
8
streptomyces albulus
8
albulus m-z18
8
simultaneous consumption
8

Similar Publications

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!