Table 2.

Integration of dark- and photo-fermentative bacteria in a single stage hydrogen production from biowastes

Organisms	Substrate (concentration: g/l)	Process parameters							H2 Yield (mol/mol hexose)	References
		Inoculum ratioa	Light intensityc	Reactor capacity (L)	pH	Temp. (°C)	IPh	Culture mode
Activated sludge + Rhodobacter sphaeroides	Wheat starch (5.0)	1:3	5,000 lux	0.25	7.0	30	–i	Continuousk (HRTl–8)	3.40	[63]
	Wheat starch (5.95)	1:2	10,000 lux	0.31	7.5	30	8	Batch	1.45	[39]
	Wheat starch (10.0)	1:2	5,000 lux	2.00	7.5	30	10	Fed-batch	1.32o	[61]
	Wheat starch (12.8)	1:2	6,000 lux	0.31	7.5	30	12	Batch	0.28–0.36o	[62]
Activated sludge + Rhodobacter sp. and Rhodopsedomonas palustris	Wheat starch (2.5)	1:7	9,500 lux	0.31	7.5	30	8	Batch	1.05	[64]
	Wheat starch (5.0)	1:7	9,500 lux	0.31	7.3	30	13	Batch	1.16	[65]
	Wheat starch (20.0)	1:2	9,500 lux	2.00	7.5	30	11	Combined fed-batch	0.43o	[42]
Activated sludge + Rhodospirillum rubrum	Cassava starch (COD, 20)	1:1	6,000d candela/m2	0.075	7.2	30	–	Batch	340p	[71]
Lactobacillus amylovorus + Rhodobium marinum	Algal biomass (Starch, 4.05)	0.5:0.6	330 W/m2	0.07	6.5	30	16	Batch	7.30	[29]
Clostridium beijerinkii + R. sphaeroides	Wheat starch (5.0)	1:3.9	10,000 lux	7.63	7.3	32	–	AHBm (HRT-6)	0.60	[41]
	Wheat starch (12.8)	1:2	6,000 lux	0.31	7.5	30	12	Batch	0.12–0.15o	[62]
Clostridium butyricum + Rhodobacter sp.	Starch (5.0)	2:3	5,000 lux	TTf	6.5	30	8–40j	Bacth and fed-batchn	4.50–6.60	[68]
Citrobacter freundii and Enterobacter aerogenes + R. palustris	Sugar cane effluent (Sugar, 7.9)	1:1:1b	NAe	10–100g	7.0	37	2	Batch	2.76	[66]
Vibrio fluvialis + Rhodobium marinum	Algal biomass (Starch, 4.05)	2:1	330 W/m2	0.07	7.0	30	9	Batch	6.20	[67]

^aDark/light organisms

^bCo-cultures

^cContinuous light

^dDark and light periods of 12 h each also

^eNot applicable

^fTest tube with dimension of 2.4 × 20 cm²

^gReactor dimensions in m³

^hIncubation period in days

ⁱValues not given

^jDifferent sets of experiment

^kPeriodic feed

^lHydraulic retention time in days

^mAnnular-hybrid bioreactor

ⁿRepeated

^oValues converted from the original data

^pml H₂/g COD