Page 485 - Refining Biomass Residues for Sustainable Energy and Bioproducts

442 Refining Biomass Residues for Sustainable Energy and Bioproducts

H2 pressure. The works published till date on sorbitol production have been focused
on the use of woody biomass, such as forestry wastes, agricultural residues, crops,
as feedstock. The conversion of food waste offers excellent opportunities, as the
derived sugars can be converted to sorbitol using similar process detailed
previously.
The most popular method for production of itaconic acid is through fermentation
using osmophilic fungus, Aspergillus terreus. Some yeast strains belonging to the
genus Candida and Pseudozyma antartica have also been reported for itaconic acid
production (Levinson et al., 2006). However, most of the biotechnological methods
have used glucose as a feed for the microorganisms. Saha et al. has reported that
the production cost of itaconic acid by fermentation from glucose is not economi-
cally feasible and has suggested the use of alternate food sources such as lignocellu-
losic and agricultural biomass as a source of fermentable sugars (Saha, 2017). The
use of market refuge apple and banana extracts (90 g/L) as substrates for fermenta-
tion by A. terreus mutant strains N45 and UNCS gave yields of 29 30 and

31 32 g IA/L, respectively, in 6 days at 34 C and pH 3.0 (Reddy and Singh,
2002). Very few literature reports are available to date on the production of itaconic
acid from food-based feedstock; it provides a lucrative possibility for future
research.
Production of 3-HP acid is performed using renewable raw materials such as glu-
cose, xylose, and other sugars using microorganisms. The present literature on 3-
HP production involves the use of sugar sources such as sucrose from sugar beet
and sugarcane and glucose from the hydrolysis of cornstarch. There are very few
reports which use lignocellulosic-derived sugars for the production of 3-HP. The
pathways for its synthesis from glucose have been identified as the Malonyl-CoA
Pathway, the β-Alanine Pathway, the Propionyl-CoA Pathway, or the Glycerate
pathway (Matsakas et al., 2018). Its production using sugars derived from food
waste is not yet researched and presents new avenues.
Commercial synthesis of (S)-3HBL is being done conventionally by chemical
synthesis process employing high-pressure hydrogenation of L-malic acid using a
ruthenium-based catalyst in a fixed-bed reactor. The chemical and chemoenzymatic
routes developed for 3-hydroxybutyrolactone (3HBL) syntheses have several disad-
vantages like the use of hazardous materials, expensive reactants, low yield, and
expensive downstream processing.
Martin et al. (2013) has reported a platform pathway for the production of 3-
hydroxy acids which provides a biosynthetic route to 3-hydroxy-c-butyrolactone. In
another report engineering, E. coli strain was used for the biosynthesis of 3-
hydroxy-γ-butyrolactone (3HBL) using glucose as a sole carbon source.

19.5 Outlook and conclusion

Change in consumer habits, strict rules and regulations, and waste management/
recycling of materials is the need of the hour for minimizing the waste worldwide.