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Agroresidue-based biorefineries 253

Mao et al. (2018) reported efficient two-stage fermentation for the production of
succinic acid by metabolic engineered C. glutamicum CG 55 using corn stalk
hydrolyzate. The strain produced 98.6 g/L of succinic acid with a productivity of
4.29 g/L/h under anaerobic conditions. Liu et al. (2013) constructed a recombinant
Escherichia coli strain BA305, with improved anaerobic simultaneous utilization of
glucose and xylose. Fed-batch fermentation using sugarcane bagasse hydrolyzate
resulted in the production of 39.3 g/L of succinic acid.
Hodge et al. (2009) reported succinic acid production by E. coli using enzymatic
hydrolyzate obtained from corn stalk. The strain produced 57.8 g/L of succinic
acid. It was observed that succinic acid production was reduced to 42.4 g/L when
enzymatic hydrolyzate of soft wood was used for succinic acid production.

11.2.5 Amino acids

Detoxified acid pretreatment liquor was evaluated for the production of amino acid
by Christopher et al. (2016). Detoxification was carried out using adsorbent or
anion exchange resins. The detoxified liquor was used for L-lysine production using
wild and mutant strains of C. glutamicum. The study revealed that detoxification resulted
in improved L-lysine production by both wild and mutant strains of C. glutamicum.
L-Lysine yields from detoxified hydrolyzates by mutant and wild strains were 9 and
30 mM, respectively.
Potential of sugarcane bagasse as an inert support for L-lysine production was
evaluated by Anusree et al. (2015). Sugarcane bagasse serves as a low-cost inert
matrix for the production of amino acid—L-lysine by C. glutamicum DM 1729.
Media engineering was carried out by statistical design experiments. The optimum
conditions for L-lysine production were incubation time of 96 h, initial moisture
content of 70%, and initial sugar concentration of 7.5% w/v. Under optimized con-
ditions, strain produced 16 mg/gds of L-lysine.
Amino acid production by recombinant C. glutamicum from rice straw and
wheat bran hydrolyzate was reported by Gopinath et al. (2011). The study revealed
that recombinant C. glutamicum coutlized arabinose and xylose from rice straw and
wheat bran hydrolyzate. Addition of ethambutol enhanced production up to 93 mM
L-glutamate by the wild type derived pentose utilizing recombinant and up to
42 mM L-lysine by recombinant pentose utilizing lysine producer on media contain-
ing rice straw and wheat bran hydrolyzate as carbon source.

11.2.6 Platform chemicals
Biotransformation of agroresidues to various platform chemicals is a promising
strategy for biorefining. Different platform chemicals, such as 1,3-propanediol,
1,2,4-butanetriol, and 2,3-butanediol, were reported to be produced from
agroresidues.
SSF as a potential strategy for the production of 2,3-butanediol was evalu-
ated by Hazeena et al. (2019). The results indicate that SSF of oil palm front
residue resulted in 30.74 g/L of 2,3-butanediol in shake flask experiments and