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Graphical abstract The PEL process ((a) sawdust and cellulose, (b) corn cob and holocellulose, (c) corn stalk and lignin, (d) rice straw, (e) brief schematic diagram of PEL experimental apparatus, (f) gas product, (g) liquid product, (h) solid residue). Highlights • Discharge characteristics and catalytic efficiency of four catalysts were compared. • The liquefaction yield of sawdust reached 97.20% in 2 min. • A high liquefaction yield was obtained in the presence of a salt catalyst. • Cellulose, holocellulose, and lignin were extracted and liquefied successfully. • Plasma electrolytic technology could successfully liquefy lignocellulosic biomass. Abstract In this research, we compared the discharge characteristics and catalytic efficiency of sulfuric acid, p-toluenesulfonic acid, and their respective sodium salts (sodium sulfate and sodium p-toluenesulfonate) in sawdust liquefaction and found that sulfuric acid was the optimal catalyst when glycerol was used as solvent during the plasma electrolytic liquefaction (PEL) process. When sodium p-toluenesulfonate was used as the only catalyst, the liquefaction yield reached 83.51% after 25 min. This yield was higher than that obtained using sodium sulfate as the catalyst (60.63%) because different concentrations of H ions were produced in PEL. Cellulose, lignin, and holocellulose were extracted from sawdust and successfully liquefied in PEL, illustrating the universality of PEL. The optical emission spectra of the different biomass during the PEL process were similar, indicating that the kinds of free radicals produced were similar, which can accelerate the liquefaction of sawdust. [ABSTRACT FROM AUTHOR]

[Display omitted] • New approach to improve the yields of astaxanthin in Phaffia rhodozyma. • Plasma-activated water (PAW) generates oxidative stress in Phaffia rhodozyma. • Mechanisms of higher astaxanthin production revealed by proteomics analysis. • Prospective biotechnology based on PAW for sustainable astaxanthin production. Astaxanthin is used extensively in the nutraceutical, aquaculture, and cosmetic industries. The current market necessitates higher astaxanthin production from Phaffia rhodozyma (P. rhodozyma) due to its higher cost compared to chemical synthesis. In this study, a bubble discharge reactor was developed to generate plasma-activated water (PAW) to produce PAW-made yeast malt (YM) medium. Due to oxidative stress induced by PAW, strains cultured in 15 and 30 min-treated PAW-made medium produced 7.9 ± 1.2 % and 12.6 ± 1.4 % more carotenoids with 15.5 ± 3.3 % and 22.1 ± 1.3 % more astaxanthin, respectively. Reactive oxygen species (ROS) assay results showed that ROS generated by plasma-water interactions elevated intracellular ROS levels. Proteomic analysis revealed increased expression of proteins involved in the cellular response to oxidative stress as well as carotenoid biosynthesis, both of which contribute to higher yields of astaxanthin. Overall, this study supports the potential of PAW to increase astaxanthin yields for industrial-scale production. [ABSTRACT FROM AUTHOR]