One milliliter of fermentation broth was collected every day during the entire fermentation period by centrifugation at 8000 g for 5 min. The cell pellet was washed with 0.7% saline solution and dried using a vacuum freezer dryer to obtain the total biomass.
TL content and fatty acid composition were determined from 5 mL of culture according to our previous report [46 (link)]. Briefly, 5 mL of fermentation broth was mixed with 5 mL of HCl (12 mol/L) and incubated at 65 °C for 30 min. After transesterification, the mixture was extracted 5 times with 3 mL of n-hexane and evaporated to dryness by nitrogen flow. The samples were then redissolved in 5 mL of 0.5 M KOH–CH3OH and 5 mL of 30% BF3-ether and applied to a gas chromatograph (Agilent GC 7890, USA) equipped with a 100 m × 0.25 mm capillary column (SP-2560, USA). Deuterated myristic acid (Sigma, Burlington, USA) was used as an internal standard.
TL content and fatty acid composition were determined from 5 mL of culture according to our previous report [46 (link)]. Briefly, 5 mL of fermentation broth was mixed with 5 mL of HCl (12 mol/L) and incubated at 65 °C for 30 min. After transesterification, the mixture was extracted 5 times with 3 mL of n-hexane and evaporated to dryness by nitrogen flow. The samples were then redissolved in 5 mL of 0.5 M KOH–CH3OH and 5 mL of 30% BF3-ether and applied to a gas chromatograph (Agilent GC 7890, USA) equipped with a 100 m × 0.25 mm capillary column (SP-2560, USA). Deuterated myristic acid (Sigma, Burlington, USA) was used as an internal standard.
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