Efficiently unsterile polyhydroxyalkanoate production from lignocellulose by using alkali-halophilic Halomonas alkalicola M2

[Display omitted] •An alkali-halophilic was isolated for lignin degradation and PHA production.•An open unsterile PHA production from lignocellulose was developed.•A record yield of 2.1 g/L PHA was produced from the APL.•A total of 5.9 g PHA was accumulated from 100 g bamboo powder. The alkali-halophilic Halomonas alkalicola M2 was isolated and developed for an open unsterile polyhydroxyalkanoate (PHA) fermentation from lignocellulose at pH 10.0 and NaCl 70 g/L. The alkaline pretreatment liquid (APL) was converted into PHA by the strain, which was significantly affected by the cultural conditions, including pH, NaCl concentration, nitrogen source, and APL concentration. The extracted PHA was composed of three monomers and similar in physicochemical properties to conventional short chain-length PHA. A record yield of 2.1 and 5.9 g of PHA was accumulated from 100 g dry bamboo powder (BP) by using APL and APL combined with hydrolysate during a 48-h open unsterile fermentation process, respectively. In summary, the alkali-halophilic H. alkalicola M2 achieved the open unsterile fermentation for lignocellulose efficient bioconversion into PHA under high alkalinity and salinity conditions and would be an ideal producer in the field.