کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
4752225 | 1415999 | 2016 | 8 صفحه PDF | دانلود رایگان |
- Sophorolipids (SLs) are produced by solid-state fermentation (SSF) of organic wastes.
- Starmerella bombicola grows on a mixture of winterization oil cake, molasses and straw.
- S. bombicola produced 0.179Â g of SL per g dry matter in 10Â days.
- Mixing at 3, 5 and 7Â days increased SL production to 0.235Â g per g dry matter.
- SL yield correlates linearly with cumulative oxygen consumption.
Sophorolipids (SLs) are a group of extracellular biosurfactants produced by the yeast Starmerella bombicola. The present study explored the use of winterization oil cake (WOC), a residual oil cake that comes from the oil refining industry, as a substrate for the production of SLs by solid-state fermentation (SSF). Sugar beet molasses (MOL) was used as a co-substrate and S. bombicola ATCC 22214 as the inoculum. Fermentation was performed on the 100-g scale and was optimized in terms of the ratio of substrates and the aeration rate using response surface methodology. The optimized SSF process (1:4 MOL:WOC mass ratio and 0.30Â LÂ kgâ1Â minâ1 aeration rate), carried out under static conditions, was monitored for 10Â days with a maximum SL yield of 0.179Â g per g DM (dry matter). The effect of intermittent mixing on the process was also investigated. Mixing caused a 31% increase in SL production, with a total yield of 0.235Â g per g DM. The Oxygen Uptake Rate (OUR) and the Cumulative Oxygen Consumption (COC) were used to monitor the biological activity of the fermentation processes. There were significant correlations between the SL yield and the oxygen and fats consumed. The SLs were characterized by FTIR and 1H NMR analysis.
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Journal: Biochemical Engineering Journal - Volume 115, 15 November 2016, Pages 93-100