Production of docosahexaenoic acid by a novel isolated Aurantiochytrium sp. 6-2 using fermented defatted soybean as a nitrogen source for sustainable fish feed development

We focused on the production of docosahexaenoic acid (DHA)-containing microbial lipids by Aurantiochytrium sp. using of defatted soybean (DS) as a nitrogen source. Defatted soybean is a plant biomass that could provide a sustainable supply at a low cost. Results showed that Aurantiochytrium sp. could not directly assimilate the DS as a nitrogen source but could grow well in a medium containing DS fermented with rice malt. When cultivated in a fermented DS (FDS) medium, Aurantiochytrium sp. showed vigorous growth with the addition of sufficient sulfate and chloride ions as inorganic nutrients without seawater salt. A novel isolated Aurantiochytrium sp. 6-2 showed 15.8 ± 3.4 g/L DHA productivity (in 54.8 ± 12.1 g/L total fatty acid production) in 1 L of the FDS medium. Therefore, DHA produced by Aurantiochytrium sp. using FDS enables a stable and sustainable DHA supply and could be an alternative source of natural DHA derived from fish oil.

Lactobacillus plantarum C29-Fermented Soybean (DW2009) Alleviates Memory Impairment in 5XFAD Transgenic Mice by Regulating Microglia Activation and Gut Microbiota Composition

SCOPE

The study aims to determine whether Lactobacillus plantarum C29-fermented defatted soybean (FDS, DW2009) can attenuate memory impairment in 5XFAD transgenic (Tg) mice.

METHODS AND RESULTS

Oral administration of FDS or C29 increases cognitive function in Tg mice in passive avoidance, Y-maze, novel object recognition, and Morris water maze tasks. FDS or C29 treatment significantly suppresses amyloid-β, β/γ-secretases, caspase-3 expression, and NF-κB activation, and activates microglia and apoptotic neuron cell populations, and increases BDNF expression in the brain. FDS or C29 treatment suppresses blood and fecal lipopolysaccharide levels and Enterobacteriaceae population and increases lactobacilli/bifidobacteria populations.

CONCLUSION

FDS and C29 alleviates the decrease in cognitive function and inhibited amyloid-β expression in Tg mice by regulating microglia activation and gut microbiota composition.