Presentation Information
[P02-280]Development of solid-state fermentation technology for the production of valuable lipids from food industry waste
○Kenshi Watanabe1, Tsunehiro Aki1 (1. Hiroshima University (Japan))
Keywords:
solid state fermentation,upcycling,biorefinery,lipid production,polyunsaturated fatty acids,carotenoids
1. Introduction
Fruit juice pomace is an underutilized biomass generated in large quantities worldwide. Its high moisture content and susceptibility to spoilage result in high processing costs, limiting its use to low-value applications such as disposal or composting. This study attempted to convert juice pomace into high-value lipids, including polyunsaturated fatty acids (PUFAs) and carotenoids, using the marine oleaginous microorganism Aurantiochytrium sp.
Conventional biomass utilization with Aurantiochytrium sp. relies on submerged liquid cultivation, which requires large volumes of water, increasing costs, and environmental burdens. This study aimed to establish a solid-state fermentation (SSF) method in which Aurantiochytrium sp. is directly inoculated onto juice pomace for growth and lipid production, yielding a composite biomass enriched with PUFAs and carotenoids for use in health foods and high-value aquaculture and livestock feeds.
2. Experimental Procedures
2.1 Materials
Apple, lemon, and mandarin orange were homogenized and pressed through gauze to separate juice from pomace. The pomace was adjusted to pH 6.5 with sodium hydroxide and autoclaved (121°C, 20 min). Yeast extract, hipolypeptone, and artificial seasalts were aseptically added. A high-carotenoid-producing Aurantiochytrium strain was inoculated, mixed thoroughly, and cultivated statically at 28°C for 5 days.
2.2 Measurements
Growth on pomace was assessed by optical microscopy. Lipids were extracted before and after SSF; carotenoids were quantified by HPLC and fatty acids by GC to evaluate changes in lipid composition.
3. Results and Discussion
After 5 days of SSF, the pomace turned vivid orange-red, likely due to intracellularly accumulated carotenoids, and numerous Aurantiochytrium cells were observed microscopically. Carotenoid and fatty acid contents increased markedly following SSF.
No growth was observed on glass beads used as a control substrate, indicating that the microorganism utilized sugars such as glucose and fructose in the pomace as carbon sources, in addition to the added yeast extract and hipolypeptone.
As an aerobic microorganism, Aurantiochytrium requires oxygen for growth. Under static cultivation, growth occurred only at the pomace surface. To improve substrate utilization and lipid production, we are currently investigating pomace pelletization to increase surface area and the use of drum-type agitated bioreactors.
4. Conclusion
Direct inoculation of Aurantiochytrium onto fruit juice pomace was confirmed to enable lipid production. Future work will address bioprocess optimization to improve conversion efficiency, and the functional properties of the resulting composite biomass, including antioxidant activity, will be comprehensively evaluated.
Fruit juice pomace is an underutilized biomass generated in large quantities worldwide. Its high moisture content and susceptibility to spoilage result in high processing costs, limiting its use to low-value applications such as disposal or composting. This study attempted to convert juice pomace into high-value lipids, including polyunsaturated fatty acids (PUFAs) and carotenoids, using the marine oleaginous microorganism Aurantiochytrium sp.
Conventional biomass utilization with Aurantiochytrium sp. relies on submerged liquid cultivation, which requires large volumes of water, increasing costs, and environmental burdens. This study aimed to establish a solid-state fermentation (SSF) method in which Aurantiochytrium sp. is directly inoculated onto juice pomace for growth and lipid production, yielding a composite biomass enriched with PUFAs and carotenoids for use in health foods and high-value aquaculture and livestock feeds.
2. Experimental Procedures
2.1 Materials
Apple, lemon, and mandarin orange were homogenized and pressed through gauze to separate juice from pomace. The pomace was adjusted to pH 6.5 with sodium hydroxide and autoclaved (121°C, 20 min). Yeast extract, hipolypeptone, and artificial seasalts were aseptically added. A high-carotenoid-producing Aurantiochytrium strain was inoculated, mixed thoroughly, and cultivated statically at 28°C for 5 days.
2.2 Measurements
Growth on pomace was assessed by optical microscopy. Lipids were extracted before and after SSF; carotenoids were quantified by HPLC and fatty acids by GC to evaluate changes in lipid composition.
3. Results and Discussion
After 5 days of SSF, the pomace turned vivid orange-red, likely due to intracellularly accumulated carotenoids, and numerous Aurantiochytrium cells were observed microscopically. Carotenoid and fatty acid contents increased markedly following SSF.
No growth was observed on glass beads used as a control substrate, indicating that the microorganism utilized sugars such as glucose and fructose in the pomace as carbon sources, in addition to the added yeast extract and hipolypeptone.
As an aerobic microorganism, Aurantiochytrium requires oxygen for growth. Under static cultivation, growth occurred only at the pomace surface. To improve substrate utilization and lipid production, we are currently investigating pomace pelletization to increase surface area and the use of drum-type agitated bioreactors.
4. Conclusion
Direct inoculation of Aurantiochytrium onto fruit juice pomace was confirmed to enable lipid production. Future work will address bioprocess optimization to improve conversion efficiency, and the functional properties of the resulting composite biomass, including antioxidant activity, will be comprehensively evaluated.
Comment
To browse or post comments, you must log in.Log in