Impact of Inoculation Strategy on the Progress of Candida rugosa Cultivation

Figures & data

Figure 1.  Variation in biomass with time in the cultivation of C. rugosa (one-step inoculation; carbon source: triolein; nitrogen source: 4 g/l urea; T = 30°C; N = 150 rpm).

Figure 2.  Variations in extracellular lipase and esterase activities with time in the cultivation of C. rugosa (one-step inoculation; carbon source: triolein; nitrogen source: 4 g/l urea; T = 30°C; N = 150 rpm).

Figure 3.  Variations in intracellular lipase and esterase activities with time in the cultivation of C. rugosa (one-step inoculation; carbon source: triolein; nitrogen source: 4 g/l urea; T = 30°C; N = 150 rpm).

Table 1.  Protease activities for one-step and two-step inoculation strategies at the end of cultivations of C. rugosa in the presence of triolein and oleic acid (T = 30°C, N = 150 rpm, nitrogen source: 4 g/l urea)

	Extracellular protease activity (U/ml; U/mg dw)		Intracellular protease activity (U/mg dw)
Carbon source	One-step inoculation	Two-step inoculation	One-step inoculation	Two-step inoculation
Triolein (2 g/l)	5.50; 5.00	–	0.05	1.39
Triolein (3 g/l)	0.16; 0.10	1.49; 0.48	0.29	0.13
Triolein (5 g/l)	0.73; 0.23	3.24; 0.91	0.14	0.92
Oleic acid (3 g/l)	4.86; 3.70	2.67; 0.60	0.67	4.97

Figure 4.  Variation in biomass with time in the cultivation of C. rugosa (two-step inoculation; carbon source: triolein; T = 30°C; N = 150 rpm).

Figure 5.  Variations in extracellular lipase and esterase activities with time in the cultivation of C. rugosa (two-step inoculation; carbon source: triolein; T = 30°C; N = 150 rpm).

Figure 6.  Variations in intracellular lipase and esterase activities with time in the cultivation of C. rugosa (two-step inoculation; carbon source: triolein; T = 30°C; N = 150 rpm).

Table 2. Comparison of maximum extracellular lipase and esterase productivities and yields of C. rugosa in the presence of triolein and oleic acid by using two different inoculation strategies (T = 30°C, N = 150 rpm, nitrogen source: 4 g/l urea, Y: yield, L: lipase activity (U/ml), E: esterase activity (U/ml), So: initial substrate concentration (mg/ml), X: biomass concentration (mg/ml))

		Max extracellular productivity (U/ ml h)		Max extracellular specific productivity (U/mg dw h)
Carbon source	Inoculation strategy	Lipase	Esterase	Lipase	Esterase	Max yield of lipase activity YL/So (U/mg)	Max yield of esterase activity YE/So (U/mg)	Max yield of biomass YX/So (mg/mg)
Triolein (2 g/l)	One-step	0.53	3.0×10^−5	0.37	2.8×10^−5	8.33	8.7×10^−4	0.74
	Two-step	0.33	5.6×10^−5	0.12	1.9×10^−5	8.33	1.7×10^−3	1.45
Triolein (3/l)	One-step	0.36	1.1×10^−5	0.20	6.3×10^−6	5.55	1.7×10^−4	0.60
	Two-step	0.21	4.3×10^−5	0.07	1.8×10^−5	4.44	5.4×10^−4	1.04
Triolein (5 g/l)	One-step	0.53	8.0×10^−6	0.13	5.1×10^−6	2.66	4.0×10^−5	0.52
	Two-step	0.17	–	0.07	–	1.33	–	0.71
Oleic acid	One-step	0.66	–	0.46	–	5.55	–	0.47
(3 g/l)	Two-step	0.36	3.1×10^−4	0.22	1.9×10^−4	5.55	8.2×10^−3	0.61

Figure 7.  Variations in biomass, extracellular and intracellular enzyme activities with time in the cultivation of C. rugosa (one-step inoculation; carbon source: 3 g/l oleic acid; T = 30°C; N = 150 rpm).

Figure 8.  Variations in biomass, extracellular and intracellular enzyme concentrations with time in the cultivation of C. rugosa (two-step inoculation; carbon source: 3 g/l oleic acid; T = 30°C; N = 150 rpm).