Table 3.

Cost of productive media and their C:N ratio.

Productive medium*	C:N ratio	Medium cost (USD/L)	Glycolipid cost (USD/g)		Glycolipid properties
			Extracellular	Cell-bound	Surface tension (mN/m)		CMC (g/L)
					Extracellular	Cell-bound	Extracellular	Cell-bound
Basal medium with soybean oil**	2.3	0.87	2.72	2.34	31.3	32.6	1.6	3.2
Basal medium with soybean oil	2.3	0.86	2.54	2.24	33.8	34.4	2.0	3.7
Basal medium with waste frying oil	2.3	0.85	4.00	2.61	43.5	40.8	3.0	3.6
Waste coconut water with waste frying oil	824.6	0.11	2.10	1.17	36.2	39.1	2.9	3.4

The cost of glycolipids and their properties are also shown.

*The costs of productive media were calculated from the price of each component purchased at local markets, while glycolipid costs were based on the glycolipid concentrations obtained from each medium (Table 2). Basal medium price 0.72 USD/L Reference: M&P IMPEX LTD, Thailand.

The soybean oil price is 1.57 USD/L, which was purchased from Thai Vegetable Oil Public Company Limited. The waste coconut water price is 0.10 USD/L, which was purchased from the Khlong Toei market, Bangkok, Thailand, and the price of waste frying oil was 0.49 USD/L, which was purchased from Baan Lad, Phetchaburi Province, Thailand. The C:N ratio of each productive medium was determined from the components of basal medium, waste coconut water, soybean oil and waste frying oil.

**The data were obtained from Subsanguan et al.¹⁴, and glycolipid production was carried out in shaking flasks.