Impacts of Initial Sugar, Nitrogen and Calcium Carbonate on Butanol Fermentation from Sugarcane Molasses by Clostridium beijerinckii

Abstract

Low-cost nitrogen sources, i.e., dried spent yeast (DSY), rice bran (RB), soybean meal (SM), urea and ammonium sulfate were used for batch butanol fermentation from sugarcane molasses by Clostridium beijerinckii TISTR 1461 under anaerobic conditions. Among these five low-cost nitrogen sources, DSY at 1.53 g/L (nitrogen content equal to that of 1 g/L of yeast extract) was found to be the most suitable. At an initial sugar level of 60 g/L, the maximum butanol concentration (PB), productivity (QB) and yield (YB/S) were 11.19 g/L, 0.23 g/L·h and 0.31 g/g, respectively. To improve the butanol production, the concentrations of initial sugar, DSY and calcium carbonate were varied using response surface methodology (RSM) based on Box–Behnken design. It was found that the optimal conditions for high butanol production were initial sugar, 50 g/L; DSY, 6 g/L and calcium carbonate, 6.6 g/L. Under these conditions, the highest experimental PB, QB and YB/S values were 11.38 g/L, 0.32 g/L·h and 0.40 g/g, respectively with 50% sugar consumption (SC). The PB with neither DSY nor CaCO3 was only 8.53 g/L. When an in situ gas stripping system was connected to the fermenter to remove butanol produced during the fermentation, the PB was increased to 15.33 g/L, whereas the YB/S (0.39 g/g) was not changed. However, the QB was decreased to 0.21 g/L·h with 75% SC.

Biobutanol production from pruned vine shoots

“…In a control run, employing a synthetic fermentation medium with the same carbon and nutrient content, the ABE solvent production was insufficient and not very repeatable (0.52 ± 0.47 g/L acetone, 1.32 ± 1.08 g/L butanol, 0.10 ± 0.08 g/L ethanol) with a low sugar consumption (17.16 ± 12.62%) and a butanol productivity and yield of 0.01 ± 0.01 g/L•h and 0.15 ± 0.03 g/g. This indicates that the presence of trace elements in vine shoots hydrolysate promoted cell growth as observed in other agrarian by-products [44]. These results also show that a low-cost MFM broth assured biobutanol production titers over 7.0 g/L, which can be considered above the average values obtained from most of lignocellulosic biomasses according to the available literature [45].…”

“…The high cost associated with nutrient supplementation in fermentation broths is one of the challenges to be addressed in biobutanol production [44]. To reduce the cost of using a rich fermentation medium (RFM) as the one described in section 3.2, the possibility of configuring a medium with minimal amount of nutrients (MFM) was explored, but guarantying the production of an acceptable amount of solvents.…”

Production of butanol from lignocellulosic biomass: recent advances, challenges, and prospects

“…80 Therefore, mismatching hydrolysis and fermentation processes, in which relatively low levels of sugars can be achieved by typical enzymatic hydrolysis of cellulose, is a major obstacle for lignocellulosic butanol production. 68 Achieving high concentrations of fermentable sugars is crucial for lignocellulosic butanol, and several strategies have been developed to increase the total sugar concentration from treatment process: 81 (1) using a fractionation pretreatment (e.g., organosolv pretreatment) to generate a cellulose-rich pretreated solid; (2) preparation of hydrolysates by simultaneous enzymatic hydrolysis of cellulose and hemicellulose, 82 or supplementing with starch for ABE fermentation, 83 but carbon catabolite repression (CCR) may be an issue; 84 (3) concentrating hydrolysates by ltration or evaporation, increasing the total sugar concentration to 30-80 g L À1 . 85 3.1.2 Inhibitors and detoxication processes 3.1.2.1 Lignocellulose-derived inhibitors.…”

Novel Methods Using an Arthrobacter sp. to Create Anaerobic Conditions for Biobutanol Production from Sweet Sorghum Juice by Clostridium beijerinckii

“…Haën, Seelze, Germany), 1 g/L and NaCl (Ajax, Auckland, New Zealand), 1 g/L [20,21]. Stock solutions A and C were sterilized in an autoclave at 110 • C for 28 min, whereas stock solution B was sterilized by membrane filtration using a 0.2 µm cellulose acetate membrane [22,23]. Afterwards, each stock solution (1%, v/v) was aseptically added into the sterile P2 medium.…”

“…The CMM was autoclaved at 110 • C for 28 min and sparged with OFN gas to create strictly anaerobic conditions before use. Vegetative cells at a level of 5% (v/v) from the CMM medium were inoculated into a sterile tryptoneglucose-yeast extract (TGY) medium and incubated at 37 • C for 4-6 h to obtain actively growing cells in the log phase with an OD of 0.5 (optical density at 600 nm) or 0.97 g/L of dry cell weight before use as an inoculum for the ABE fermentation [23,24]. TGY medium is comprised of 5 g tryptone (Oxoid, Basingstoke, Hants, UK), 1 g glucose (BDH, Leuvn, Belgium), 5 g yeast extract (Oxoid, Basingstoke, Hants, UK) and K 2 HPO 4 (BDH, Leuvn, Belgium) in 1 L distilled water.…”