m
Meter
MgCl 2 Á6H 2 O
Magnesium chloride hexahydrate
MgSO 4 Á7H 2 O Magnesium sulfate heptahydrate
min
Minutes
mL
Milliliter
mM
Millimolar
Na
+
Sodium ion
Na 2 SO 4
Sodium sulfate
NaCl
Sodium chloride
NaHCO 3
Sodium bicarbonate
NaOH
Sodium hydroxide
NH 4 Cl
Ammonium chloride
(NH 4 ) 2 HPO 4
Diammonium phosphate
NiCl 2 Á6H 2 O
Nickel (II)chloride hexahydrate
STP
Standard temperature and pressure (0
C, 1 atm)
T
Temperature
VFA
Volatile fatty acid
wt./vol.
Weight/volume
1 Introduction
The dependence on fossil fuels for energy supply has had great impacts on global
warming and climate change [1]. Therefore, the development of alternative renewable energy sources is being pursued globally [2]. Biohydrogen is one of the
promising candidates for future use because it is a CO 2 -free, clean, and highly
efficient energy carrier. Production of biohydrogen can be achieved through
bio-photolysis, photofermentation, and dark fermentation process [3].
Dark fermentation process offers several advantages in industrial biohydrogen
production. Among them are high production rates, high yields per mole of substrate, continuous production regardless of solar light condition [4], high variety of
carbon sources as substrates, and has no oxygen limitation since the process is fully
anaerobic [5, 6]. On the other hand, dark fermentation also has several limitations,
such as thermodynamically unfavorable condition as hydrogen yields increase and
carbon dioxide’s presence in the produced gas [6].
Among carbon sources to supply fermentable sugars in biohydrogen production,
lignocellulosic biomass is a highly considered option. It doesn’t compete with food
production, and it is available abundantly in nature as grasses and woods, in forestry
and agricultural residues, as well as in domestic and industrial wastes. It was
estimated that lignocellulosic biomass residue is being produced more than 220 billion tons annually all over the world [7]. However, lignocellulosic biomass requires
pretreatment [7] such as alkaline and heat treatment followed by hydrolysis (with
enzymes) prior to use as feedstock in fermentative hydrogen production [8]. Most
11 Biohydrogen Production from Lignocellulosic Biomass by Extremely Halotolerant. . . 413
Meter
MgCl 2 Á6H 2 O
Magnesium chloride hexahydrate
MgSO 4 Á7H 2 O Magnesium sulfate heptahydrate
min
Minutes
mL
Milliliter
mM
Millimolar
Na
+
Sodium ion
Na 2 SO 4
Sodium sulfate
NaCl
Sodium chloride
NaHCO 3
Sodium bicarbonate
NaOH
Sodium hydroxide
NH 4 Cl
Ammonium chloride
(NH 4 ) 2 HPO 4
Diammonium phosphate
NiCl 2 Á6H 2 O
Nickel (II)chloride hexahydrate
STP
Standard temperature and pressure (0
C, 1 atm)
T
Temperature
VFA
Volatile fatty acid
wt./vol.
Weight/volume
1 Introduction
The dependence on fossil fuels for energy supply has had great impacts on global
warming and climate change [1]. Therefore, the development of alternative renewable energy sources is being pursued globally [2]. Biohydrogen is one of the
promising candidates for future use because it is a CO 2 -free, clean, and highly
efficient energy carrier. Production of biohydrogen can be achieved through
bio-photolysis, photofermentation, and dark fermentation process [3].
Dark fermentation process offers several advantages in industrial biohydrogen
production. Among them are high production rates, high yields per mole of substrate, continuous production regardless of solar light condition [4], high variety of
carbon sources as substrates, and has no oxygen limitation since the process is fully
anaerobic [5, 6]. On the other hand, dark fermentation also has several limitations,
such as thermodynamically unfavorable condition as hydrogen yields increase and
carbon dioxide’s presence in the produced gas [6].
Among carbon sources to supply fermentable sugars in biohydrogen production,
lignocellulosic biomass is a highly considered option. It doesn’t compete with food
production, and it is available abundantly in nature as grasses and woods, in forestry
and agricultural residues, as well as in domestic and industrial wastes. It was
estimated that lignocellulosic biomass residue is being produced more than 220 billion tons annually all over the world [7]. However, lignocellulosic biomass requires
pretreatment [7] such as alkaline and heat treatment followed by hydrolysis (with
enzymes) prior to use as feedstock in fermentative hydrogen production [8]. Most
11 Biohydrogen Production from Lignocellulosic Biomass by Extremely Halotolerant. . . 413