improvement in normal programs in the classical strain [70]. Though the number of
classical methods includes UV and chemical mutagenesis, the advantage of the
genome shuffling over multi-parental incorporation of foreign DNA plays a significant role in the inducing or suppressing of the various genes to increase the organic
acid production [71]. The gene shuffling depends on the various parameters like the
selection of the organisms, characterization of the wild-type strain, diversity, phenotype and genotype characterization, and recombination [72]. The various organisms are genetically engineered to optimize the yield of different organic acid
productions is shown in Table 7.
8 Applications of Organic Acids in the Removal
of Metal Ions
Heavy metal accumulation in the soil is considered as the most prominent threat to
the environment. These metals are not biodegradable, and their persistent accumulation in the soil affects animals, humans, and microorganisms of the biological
system. Though various remediations like leaching, soil washing, and immobilization using chemicals methods are there, organic acids like citric acid, tartaric acid,
and ethylenediamineacetic acid act as the chelating agent that has been used to
remediate the soil from the metal pollutants [82]. Various metal contaminants, when
Table 6 Production of other organic acids from agricultural by-products
Feedstock
Microbial
source
Method of
production
Yield (g g
À1
)
Organic acid
production
(g L
À1
)
References
Wheat straw,
corn stalk and
sugarcane
bagasse
Yarrowia
lipolytica
Fermentation Succinic
acid – 0.45
Succinic acid
À209.7
[63]
Sugarcane
bagasse
Aspergillus
succinogenes
Fermentation Succinic
acid – 0.81
Succinic
acid – 27.7
[64]
Cassava starch
Leuconostoc
mesenteroids
Fermentation Succinic
acid – 0.69
Succinic acid
À106.17
[65]
Apple pomace
Rhizopus
oryzae 1526
Fermentation Fumaric
acid – 0.35
Fumaric
acid – 25.2
[66]
Potato waste
Gluconobacter
oxydans DSM
2003
Hydrolysis
and
fermentation
Gluconic
acid – 0.82
Gluconic
acid – 546.48
[67]
Whey
hydrolysate
Gluconobacter
oxydans
Fermentation Galactonic
acid – 0.90
Galactonic
acid – 61.8
[68]
Sugarcane
bagasse and
orange peels
Aspergillus
oryzae
Fermentation Galacturonic
acid – 0.60
Galacturonic
acid – 247
[15]
Recent Advances in Organic Acid Production from Microbial Sources by Utilizing. . .
79
classical methods includes UV and chemical mutagenesis, the advantage of the
genome shuffling over multi-parental incorporation of foreign DNA plays a significant role in the inducing or suppressing of the various genes to increase the organic
acid production [71]. The gene shuffling depends on the various parameters like the
selection of the organisms, characterization of the wild-type strain, diversity, phenotype and genotype characterization, and recombination [72]. The various organisms are genetically engineered to optimize the yield of different organic acid
productions is shown in Table 7.
8 Applications of Organic Acids in the Removal
of Metal Ions
Heavy metal accumulation in the soil is considered as the most prominent threat to
the environment. These metals are not biodegradable, and their persistent accumulation in the soil affects animals, humans, and microorganisms of the biological
system. Though various remediations like leaching, soil washing, and immobilization using chemicals methods are there, organic acids like citric acid, tartaric acid,
and ethylenediamineacetic acid act as the chelating agent that has been used to
remediate the soil from the metal pollutants [82]. Various metal contaminants, when
Table 6 Production of other organic acids from agricultural by-products
Feedstock
Microbial
source
Method of
production
Yield (g g
À1
)
Organic acid
production
(g L
À1
)
References
Wheat straw,
corn stalk and
sugarcane
bagasse
Yarrowia
lipolytica
Fermentation Succinic
acid – 0.45
Succinic acid
À209.7
[63]
Sugarcane
bagasse
Aspergillus
succinogenes
Fermentation Succinic
acid – 0.81
Succinic
acid – 27.7
[64]
Cassava starch
Leuconostoc
mesenteroids
Fermentation Succinic
acid – 0.69
Succinic acid
À106.17
[65]
Apple pomace
Rhizopus
oryzae 1526
Fermentation Fumaric
acid – 0.35
Fumaric
acid – 25.2
[66]
Potato waste
Gluconobacter
oxydans DSM
2003
Hydrolysis
and
fermentation
Gluconic
acid – 0.82
Gluconic
acid – 546.48
[67]
Whey
hydrolysate
Gluconobacter
oxydans
Fermentation Galactonic
acid – 0.90
Galactonic
acid – 61.8
[68]
Sugarcane
bagasse and
orange peels
Aspergillus
oryzae
Fermentation Galacturonic
acid – 0.60
Galacturonic
acid – 247
[15]
Recent Advances in Organic Acid Production from Microbial Sources by Utilizing. . .
79