Background: Biodiesel, monoalkyl esters of long-chain fatty acids attached to short-chain alcohols derived from triacylglycerols (TAGs), can be produced from renewable biomass sources. There has been interest in producing TAGs from oleaginous microorganisms. As published recently (J Biotechnol. 2010; 147: 212-8), R. opacus PD630 is capable of accumulating a large amount of TAGs if grown on glucose medium. We have succeeded in constructing a variant of PD630 (MITXM-61, unplublished), which is capable of efficiently fermenting high concentrations of xylose and accumulating TAGs. In this study, the fermentative production of TAGs by MITXM-61 was investigated on a cellulosic sugar solution, saccharified from corn stover silage.
Results: We have developed a bioprocess for the preparation of a cellulosic sugar solution from corn stover silage without growth inhibitors for MITXM-61 cultivation. The wet silage material was suspended in 1% NaOH and incubated at 90°C. After filtering, the residue was washed with water, dried and ground. The pretreated material was suspended in water, adjusted to pH 5.0 and different commercial multi-enzyme complexes were added to the suspension. The reaction mixture was incubated at 45°C with shaking. After 24 h, the prepared saccharified solution contained more than 100g/L of total sugars (composed of 66% glucose, 29% xylose and 5% other sugars). R. opacus MITXM-61 was grown in a bioreactor batch-culture using the saccharified solution as growth medium. Glucose and xylose were consumed simultaneously and 16 g/L of total fatty acids was accumulated, corresponding to 58% of the cell dry weight.
Conclusion: R. opacus MITXM-61 has the rare capability of accumulating large amounts of TAGs when grown on saccharified corn stover silage solution with a high sugar concentration. This strain holds a great potential as a future source of industrial biodiesel derived from cellulosic feedstocks.
Would you like to access this content?
No problem. You just have to complete the following steps.
You have completed 0 of 2 steps.
You must be logged in to view this content. Log in now.
Purchase Technical Presentation
You must purchase this technical presentation using one of the options below.
If you already purchased this content recently, please click here to refresh the system's record of ownerships.
|Credits||0.5 Use credits|
|List Price||$25.00 Buy now|
|AIChE Members||$15.00 Buy now|
|AIChE Undergraduate Student Members||Free Free access|
|AIChE Graduate Student Members||$15.00 Buy now|