A co-fermentation strategy with wood hydrolysate and crude glycerol to enhance the lipid accumulation in Rhodosporidium toruloides-1588.

Wood hydrolysate has been regarded as sustainable and renewable substrate to produce microbial lipids, a potential feedstock for the biodiesel industry. Moreover, the major by-product of biofuel industries is crude glycerol but its implementation as a carbon source is still constrained due to the presence of impurities resulting in low biomass production and low lipid titer. Thus, this study investigates the effect of different carbon ratios of hydrolysate and crude glycerol on R. toruloides-1588. Hydrolysate to crude glycerol ratio of 60:40 resulted in maximum lipid accumulation of 49% (w/w), more than 90% of sugars and glycerol consumption. Further, scale-up to bench-scale fermenter resulted in 12% higher lipid accumulation (56.3% w/w, 0.15 g/L∙h) in 50% less time than flask fermentation. Hence, the ability of R. toruloides-1588 to flourish on different carbohydrates and accumulate high lipid content will be beneficial for the further development of biorefinery industries.

A critical insight into the development, regulation and future prospects of biofuels in Canada.

Renewable biofuel has a great potential in replacing the conventional transportation fuels as well as aiding the current issue of climate change and global warming. In the present scenario, tremendous initiatives have been implemented to encourage large-scale biofuel production and reduce greenhouse gas emissions. However, the information on the current biofuel status specifically in Canada and where it lacks in biofuel production, tax rebate and policies in comparison with other countries is limited. In this sense, the current work focuses on the liquid biofuel status, recent advancements and evaluation of programs aimed at reducing greenhouse gas emissions in coming years. Additionally, the role of private and government programs in scaling up the projects is elaborated using several examples of successful as well as failed attempts to commercialize biofuels. Moreover, the Canadian government regulations and policies for greenhouse gas mitigation, and biofuel blending policies are also briefly described. In summary, future aspects and suggestions to further increase biofuel production are portrayed in this review.

Effect of creating a fed-batch like condition using carbon to nitrogen ratios on lipid accumulation in Rhodosporidium toruloides-1588.

Utilizing the undetoxified wood hydrolysate to accumulate maximum lipids in Rhodosporidium toruloides under optimum conditions has been regarded as a renewable and cost-effective strategy. The current investigation aims to identify the best carbon to nitrogen (C/N 20, 70, and 120) ratio for maximum lipid accumulation in R. toruloides-1588 using wood hydrolysate. Additionally, a fed-batch-like condition was employed, where C/N ratios were maintained during the fermentation that inherently decreases in batch fermentation. The C/N ratio 70 has been identified as the best condition with 3 times higher lipid accumulation (43% w/w) than the control. Additionally, >95% and 70% of glucose and xylose consumption were observed, respectively. Moreover, 50% increase in polyunsaturated fatty acids compared to the control media reinforced the potential of R. toruloides-1588 to thrive on undetoxified hydrolysate, high lipid productivity (3.8 mg/g of dry weight per hour) and produce high value monosaturated and polyunsaturated fatty acids.