Page 169 - Refining Biomass Residues for Sustainable Energy and Bioproducts

A Biorefinery approach towards development of renewable platform chemicals 141

Polymerization of bio-derived monomers by lipase catalyst was used for the pro-
duction of fine chemicals. This technique has been reported to reduce temperature
under controlled environment (Kumar et al., 2003). The synthesis of 1,3-propane-
diol and itaconic acid is achieved by fermentation techniques with certain modifica-
tion in the natural routes. The presence of reactive carboxyl group helps in the
incorporation of itaconic acid to the polymers, which are used as substitute for
acrylic acid and methacrylic acid (Nakamura and Whited, 2003; Lucia et al., 2006).
Various researches suggest the direct fermentation of biomass to acrylic acid and
ethylene using natural bacteria and other microorganism (Danner and Braun, 1999;
Xu et al., 2006). The incorporation of ionic liquids in the biorefinery design process
reduces the processing steps and cost requirement with increase in the yield of final
products (Zhu et al., 2006; Li et al., 2008; Zhang et al., 2010). The conversion of
platform chemical known as 5-hydroxymethyl furfural was stabilized by the intro-
duction of chromium(II) chloride (Crd 2 )(Murakami et al., 2007; Zhao et al., 2007).
Many value-added products have been reported for the production of fine chemicals
within biological species including plants and microorganisms. Commodity chemi-
cals such as vanillin and guaiacol were produced by direct conversion of ferulic
acid as feedstock (Mullin, 2004). The polyhydroxyalkanoates (PHAs) are produced
by direct biological conversion of microbial cells (Carole et al., 2004; Munoz and
Riley, 2008; Sun et al., 2007).
Research has been focused on developing an optimizing route involving geneti-
cally modified plants for the production of fine chemicals such as PHA (Carole
et al., 2004; Suriyamongkol et al., 2007). It was investigated that the properties of
the starting material are tailored (Keenan et al., 2006). Alternatively, researchers
focused on microbial consortia rather than a single super bacterium (Coats et al.,
2007). In recent years, impressive growth was noted on the integration of metabolic
engineering and system biology for the production of chemicals (Kohlstedt et al.,
2010; Becker et al., 2010, 2011; Wittmann, 2010). Corynebacterium glutamicum
was employed for the production of diamines. Heterologs expression of Escherichia
coli gene cadA was used for the production of cadaverine with yield of 0.17 g/g
(Kind et al., 2010, 2011; Mimitsuka et al., 2007). The production of succinic acid
was reported to be increased by the overexpression of gene known as SucE I with
the yield of 0.3 g/g of glucose (Litsanov et al., 2012). The list of platform chemicals
from various sources is listed in Table 6.1.

6.5 Regulations and sustainability of bulk chemicals

The bio-based chemicals have outreached vigorous governance and regulatory
implications as they are directly related to the environmental concerns. The novel
chemical process involved in the production of chemical products either from bio-
mass or fossil sources is subjected to review under Toxic Substances Control Act.
The regulation is formulated by REACH, a European Community for the Safety of
Human and Environmental Aspects. This regulation mainly comprises the