In this research, novel biorefinery processes for obtaining value-added chemicals such as biosugar and hesperidin from mandarin peel waste (MPW) are described. Herein, three different treatment methods were comparatively evaluated to obtain high yields of biosugar and hesperidin from MPW. Each method was determined by changes in the order of three processing steps, i.e., oil removal, hesperidin extraction, and enzymatic hydrolysis. The order of the three steps was found to have a significant influence on the production yields. Biosugar and hesperidin production yields were highest with method II, where the processing steps were performed in the following order: oil removal, enzymatic hydrolysis, and hesperidin extraction. The maximum yields obtained with method II were 34.46 g of biosugar and 6.48 g of hesperidin per initial 100 g of dry MPW. Therefore, the methods shown herein are useful for the production of hesperidin and biosugar from MPW. Furthermore, the utilization of MPWs as sources of valuable materials may be of considerable economic benefits and has become increasingly attractive.
Corynebacterium glutamicum is a useful microbe to produce succinic acid,
a bio-based platform chemical, under anaerobic condition. The knock-out
mutant of lactate dehydrogenase 1 gene (ΔldhA-6) and co-expression of
succinic acid transporter (Psod:sucE- ΔldhA) were generated by using
CRISPR-Cpf1 genome editing system. HAPC (hydrogen peroxide and acetic
acid) pretreatment is a highly efficient method for enzymatic hydrolysis
of softwood and the hydrolysate was used for production of succinic
acid. In the 15% hydrolysate (Pinus densiflora), the best condition
for ΔldhA mutant to produce succinic acid from the hydrolysate was
confirmed to ferment 4% hydrolysate, resulted in 14.82 g L-1 succinic
acid production for 6 h, which reached to 2.47 g L-1 h-1 productivity.
No production of acetic acid and lactic acid was detected during the
fermentation. The co-expression transformant, [Psod:sucE- ΔldhA],
produced 17.70 g L-1 succinic acid in 6 h, presenting a productivity of
2.95 g L-1 h-1 on the 4% hydrolysate. In the fed-batch system, 39.67 g
L-1 succinic acid was produced for 48 h. The yield of succinic acid from
reducing sugars in the hydrolysate is approximately 56.71%, while the
yield of succinic acid from glucose alone as the main substrate is
approximately 84.4%. These results indicated that the production of
succinic acid from softwood has potential applications in alternative
biochemical processes, and minimizing the loss of sugars during
enzymatic hydrolysis and fermentation can lead to more economic benefits
in succinic acid production from lignocellulosic biomass.
Background: Corynebacterium glutamicum is a useful microbe to produce succinic acid, a bio-based platform chemical, under anaerobic condition. The knock-out mutant of lactate dehydrogenase 1 gene, Δldh1-6, was generated by using CRISPR-Cpf1 genome editing system. HAPC (hydrogen peroxide and acetic acid) pretreatment is a softwood-favorable.
Results: In the 1-5% hydrolysate, the best condition to produce succinic acid from the hydrolysate was confirmed to ferment 4% hydrolysate, resulted in 14.82 g L-1 succinic acid production for 6 h, which reached to 2.47 g L-1 h-1 productivity. No production of acetic acid and lactic acid was detected during the fermentation. However, 2.0 g L-1 lactic acid and 0.41 g L-1 acetic acid were formed in the fermentation of 5% hydrolysate while 9.64 g L-1 succinic acid was produced.
Conclusion: These results show that the single gene knock-out, Δldh1-6 mutant, is sufficiently available for succinic acid production from hydrolysate of pine wood.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.