Folin s phenol reagent

The amount of peptide in TJFs were measured using a lowry assay. It were Calculated by a standard curve using Bovine serum albumin (Sigma, USA). Lowry solution consists of a mixture of solution A and B (Solution A: 4 mg/mL NaOH and 20 mg/mL Na2CO3 in water Added 2 g of NaOH and 10 g of Na2CO3 to 400 mL water while stirring until completely dissolved, then adjust volume to 500 mL. Solution B: 10 mg/mL Potassium Sodium Tartrate and 5 mg/ mL CuSO4 in water). Add 100 mg Potassium Sodium Tartrate and 50 mg CuSO4 (cupric sulfate to 8 mL of water in a tube. Shake the mixture until solids are completely dissolved, adjust volume to 10 mL (50:1 mix of solutions A and B). Prepare samples by adding 2, 5, and 10 μL of sample into a glass tube and adjust total volume to 200 μL. To each tube added 1 mL Lowry’s Solution, vortex, wait for 15 mins. To each tube added 100 μL 1.0 N Folin’s Phenol reagent (Sigma, USA) while vortexing, wait for 30 mins. Absorbance is measured at 750 nm.

P. elgii TKU051 was isolated and described in a previous study [2 (link)]. Squid pens were bought from Shin-Ma Frozen Food Co. (I-Lan, Taiwan), whereas tuna, tiger shrimp, and white shrimp were bought from Danshui Carrefour supermarket (New Taipei, Taiwan). Subsequently, tuna heads, tuna viscera, and shrimp heads were obtained from the tuna and shrimp. All materials, including squid pens, shrimp heads, tuna heads, and tuna viscera, were dried in the oven (60 °C) and pulverized to powder. Folin’s phenol reagent, tyrosine, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), 2-mercaptoethanol, Cetrimonium bromide, 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH), trichloroacetic acid (TCA), E-64, phenymethylsulfonyl fluoride (PMSF), ethylenediaminetetraacetic acid (EDTA), 5,5-Dithiobis(2-nitrobenzoic acid) (DTNB), 1,10-phenanthroline were purchased from Sigma-Aldrich (Darmstadt, Germany). All other reagents used in the study were of the highest grade available.