296

18 Advancements in Bio-hydrogen Production from Waste Biomass

Table 18.3

Various genetic engineering approaches used to enhance the biohydrogen

production.

Microorganism

Genetic

approach

Target gene

Yield (mol-H2/mol-

substrate)

References

Clostridium

pasteurianum

Over expression

hydA

dhaD1

dhaK

1.11

0.93

(0.7 for wild type)

[33]

Clostridium

acetobutylicum

DSM 792

Over expression

thl promoter

1.77

(1.79 for wild type)

[60]

Clostridium

acetobutylicum

DSM 792

Over expression

hydA

1.81

(1.79 for wild type)

[60]

Enterobacter

aerogenes

ATCC 13408

Over expression

hydA

2.31

(1.18 for wild type)

[61]

Enterobacter

aerogenes

IAM1183 Ea

Over expression

fdhF

1.16

(0.96 for wild type)

[62]

Enterobacter

aerogenes

IAM1183 Ea

Over expression

fhlA

1.09

(0.96 for wild type)

[62]

Clostridium

tyrobutyricum

Knockout

Ack

2.16

(1.44 for wild type)

[32]

E. coli W3110

(SR15 mutant)

Knockout

ldhA + frdBC

1.82

(1.08 for wild type)

[56]

E. coli W3110

(SR14 mutant)

Knockout and over

expression

ldhA + frdBC and

fhlA

1.87

[56]

Clostridium

paraputrificum

M-21

Overexpression

hydA

2.4

(1.4 for wild type)

[58]

Enterobacter

cloacae IIT

BT-08 (A3

mutant)

Knockout

Alcohol dehydroge-

nase + butadienol

dehydrogenase

1.65

(2.16 for wild type)

[63]

Enterobacter

cloacae IIT

BT-08 (DM11

mutant)

Knockout

Alcohol dehydroge-

nase + butadienol

dehydroge-

nase + acid-blocking

3.4

(2.16 for wild type)

[63]

Source: Adapted from Sarma [3].

Therefore, deletion of the genes ldhA, frdBC encoding lactate dehydrogenase and

fumarate reductase, respectively, resulted in twofold increments in the molecular

H2 production. The combined approach of over-expression of formate hydrogen

lyase activator protein ( fhlA) and deletion of frdBC, ldhA caused a further increase

in H2 yield [56]. The lower yield of biological H2 is due to the negative impact of the

organic acids produced by competitive pathways. Disruption of these competitive