A sustainable approach for bioconversion of food and lignocellulosic wastes into liquid biofuel using a newMetschnikowia pulcherrimaisolate

In the present study, valorization of food and lignocellulosic wastes into biodiesel and 2-phenylethanol usingMetchinikowia pulcherrimaisolated from rotten food wastes was evaluated. At the optimum pH of 5.5, food waste hydrolysate (FWH) showed 74.1% higher dry weight than the corresponding synthetic medium. Rice straw (RS) and softwood sawdust (WWA) were used as additional carbon sources to increase the C:N ratio of FWH. WWA enhanced the biomass production by 23.3% and 55.9% over the corresponding RS and FWH, respectively; while RS enhanced lipid accumulation. Due to enhancement of growth, 75 g WWA showed the maximum recorded lipid productivity of 2.49 g L(-1)d(-1). Interestingly, both hexoses and pentoses were effectively metabolized. Regarding fatty acid profile ofM. pulcherrima, RS- and WWA-enriched growth media showed higher saturated fatty acids proportions (56.9% and 98.3%, respectively, over that of FWH), with better biodiesel characteristics. FWH showed the heights significant production of 2-phenylethanol up to 56.7 mg L(-1)after 96 hours. However, FWH enriched with WWA showed the highest gross energy output of 33.98 GJ m(-3)y(-1). Thus, the present study suggested an integrated approach ofM. pulcherrimacultivation on FWH enriched with WWA for efficient biofuel production through waste recycling.

Automated summary

The study demonstrates the feasibility of valorizing food and lignocellulosic wastes into biodiesel and 2-phenylethanol. Additional carbon sources like softwood sawdust and rice straw enhance biomass production and lipid accumulation, leading to efficient biofuel production through waste recycling.