Millex hv 0.45 m filter

The intracellular glycogen concentration in 1 mg of cells (dry weight) was collected and extracted as according to a previous study (Nakajima et al., 2017) . Glycogen concentration was measured using an EnzyChrom Glycogen Assay Kit (BioAssay Systems, Hayward, CA, USA) according to the manufacturer's instructions.
The supernatant of the culture broth was filtered to remove large size impurities using a Millex HV 0.45-µm filter (Merck KGaA, Darmstadt, Germany). The concentrations of BuOH, ethanol, pyruvate, lactate, formate, acetate, and succinate in the culture supernatant were determined using an Agilent 7890A gas chromatography (GC) system (Agilent Technologies, Santa Clara, CA, USA) equipped with a DB-WAX 123-7062 column (60 m × 0.32 mm inner diameter × 0.25 μm; Agilent Technologies) and a Prominence high-performance liquid chromatography (HPLC) system (Shimadzu, Kyoto, Japan) equipped with a UV/vis detector (SPD-20A), a refractive index detector (RID-10A), and an Aminex HPX-87X column (Bio-Rad, Hercules, CA, USA). The chromatographic conditions were as described in the previous study (Morita et al., 2017) .

The sixth-passage DFAT were placed in 100 mm dishes and allowed to grow at 37 °C in 5% CO 2 until the cells reached 70% confluence. After washing with PBS, the medium was replaced with 5 mL of DMEM containing 5% FBS. The DFAT were incubated for 72 h, and the supernatant was collected and centrifuged at 1,500 g for 10 min. The supernatant was passed through a Millex-HV 0.45 µm filter (Merck Millipore, Burlington, MA). The collected DFAT-CM were frozen at -80 °C and thawed on the day of the experiments.