Lipid production by the filamentous cyanobacterium Limnothrix sp. growing in synthetic wastewater in suspended- and attached-growth photobioreactor systems

Table 1 Comparison of performance of suspended- and attached-growth systems

	Suspended system^a	Attached system^a	Suspended system^b	Attached system^b
Maximum biomass^*	141 mg/L	2.5 g/m² (89.68 mg/L)	291 mg/L	5.2 g/m² (190.5 mg/L)
Total biomass in PBR	141 mg/L	7.24 g/m^2 (252 mg/L)^	291 mg/L	22.12 g/m^2 (770 mg/L)^
Maximum oil^*	32 mg/L	0.6 g/m² (21.44 mg/L)	43 mg/L	0.5 g/m² (17.47 mg/L)
Total oil in PBR	32 mg/L	1.52 g/m^2* (52.94 g/L)^*	43 mg/L	1.58 g/m^2* 54.46 mg/L^*
Oil in biomass on glass rods (%)	–	24.14	–	14.12
Oil in total biomass of PBR (%)	26.89	21.01	16.8	7.07
Total biomass productivity (mg/L∙day)	20.14	38.77	22.38	35.00
Total biomass productivity (g/m²·day)	–	1.11	–	1.01
Total oil productivity (mg/L∙day)	4.57	8.14	3.31	2.48
Total oil productivity (g/m² ∙day)	–	0.23	–	0.07
NO₃ ⁻ removal (%)	93.05	80.90	96.69	96.92
PO₄ ⁻² removal (%)	98.86	98.54	93.14	98.81
Total surface of glass rods (m²)	–	0.1276	–	0.1276
Total surface of PBR walls (m²)	–	0.1199	–	0.1199
Total surface of PBR (rods and walls) (m²)	–	0.2475	–	0.2475
Volume of PBR (mL)	3500	3500	3500	3500
Cultivation time (days)	7	6.5	13	22

^aKinetic experiment under low nutrient concentrations (Fig. 2)
^bKinetic experiment under high nutrient concentrations (Fig. 3)
^*Concentration at the end of the experiment. In the case of suspended cultivation, maximum biomass is equal to total biomass and maximum oil is equal to total oil.
^**Sum of attached biomass on glass rods and PBR walls
^***Sum of produced oil on glass rods and PBR walls

ISSN: 1869-2044