100
Sugarcane bagasse has been proven as a promising biomass to produce IA [86].
Haigh et al. recently compared economic viability of different bio-based feedstocks
and concluded that utilization of sugarcane bagasse can help to reduce the cost of IA
production and make IA biorefinery commercially viable [87]. Life cycle assessment for production of IA from sugarcane bagasse was also conducted recently by
Görgens and co-workers [88]. Paranthaman et al. developed an integrated process
for IA production by using less expensive sugarcane bagasse in place of refined
glucose [89]. In this process, four fungi, namely, Aspergillus oryzae, Aspergillus
niger, Aspergillus flavus, and Penicillium sp., were chosen and improved their activities in solid-state fermentation. Under the best fermentation conditions and pH,
A. niger yielded the highest IA level (8.24 mg kg
−1
) in a shake flask. In 2018,
Dinakarkumar et al. screened and fermented different agro-wastes using Aspergillus
niveus. They achieved the best results with sugarcane bagasse [90].
3 Acrylic Acid
AA is an essential monomer for the manufacture of various industrial and consumer
products [91]. AA market size was about $11,006 million in 2013 and is anticipated
to reach $18,824 million by 2020 [92]. According to global opportunity analysis
and industry forecast, global consumption of AA is expected to reach 8169 kilotons
by 2020 [93]. However, renewable feedstock-derived AA is not cost-competitive to
petroleum-derived AA because of maturity of petrochemical industries and processing [94]. Environmental sustainability and demand-supply imbalance of petroleum
warrant production of bio-based AA and acrylates from glycerol, sugar, LA, acrolein, and intermediate feedstocks [95].
3.1 Bio-catalytic Routes to Acrylic Acid
Currently, Clostridium propionicum, obtained from coupled oxidation/reduction of
alanine, is used to produce AA [96, 97], under its acrylate form from Clostridium
propionicum bacteria. In 1981, O’Brien et al. tested resting cells of Clostridium
propionicum for biotransformation of propionate to AA [98]. However, the less stability of anaerobic cells under an aerobic environment resulted in relatively low
yield of AA (up to 18%). In 1990, the same group used sweet whey as an initial
substrate for acrylate production in a two-step process [99]. In the first step, sweet
whey was converted to propionic acid and acetic acid in 70 h by a co-culture of
Lactobacillus bulgaricus and Propionibacterium shermanii. In the second step, propionate was converted into acrylate by resting cells of Clostridium propionicum. In
this process, maximum acrylate of 0.133 mmol g
−1
AA was produced in 6 h. When
Clostridium propionicum was grown on bio-based LA, and provided with methylene blue as an electron acceptor, it produced 144 mg L
−1
AA [97]. It was found that
K. Avasthi et al.
Sugarcane bagasse has been proven as a promising biomass to produce IA [86].
Haigh et al. recently compared economic viability of different bio-based feedstocks
and concluded that utilization of sugarcane bagasse can help to reduce the cost of IA
production and make IA biorefinery commercially viable [87]. Life cycle assessment for production of IA from sugarcane bagasse was also conducted recently by
Görgens and co-workers [88]. Paranthaman et al. developed an integrated process
for IA production by using less expensive sugarcane bagasse in place of refined
glucose [89]. In this process, four fungi, namely, Aspergillus oryzae, Aspergillus
niger, Aspergillus flavus, and Penicillium sp., were chosen and improved their activities in solid-state fermentation. Under the best fermentation conditions and pH,
A. niger yielded the highest IA level (8.24 mg kg
−1
) in a shake flask. In 2018,
Dinakarkumar et al. screened and fermented different agro-wastes using Aspergillus
niveus. They achieved the best results with sugarcane bagasse [90].
3 Acrylic Acid
AA is an essential monomer for the manufacture of various industrial and consumer
products [91]. AA market size was about $11,006 million in 2013 and is anticipated
to reach $18,824 million by 2020 [92]. According to global opportunity analysis
and industry forecast, global consumption of AA is expected to reach 8169 kilotons
by 2020 [93]. However, renewable feedstock-derived AA is not cost-competitive to
petroleum-derived AA because of maturity of petrochemical industries and processing [94]. Environmental sustainability and demand-supply imbalance of petroleum
warrant production of bio-based AA and acrylates from glycerol, sugar, LA, acrolein, and intermediate feedstocks [95].
3.1 Bio-catalytic Routes to Acrylic Acid
Currently, Clostridium propionicum, obtained from coupled oxidation/reduction of
alanine, is used to produce AA [96, 97], under its acrylate form from Clostridium
propionicum bacteria. In 1981, O’Brien et al. tested resting cells of Clostridium
propionicum for biotransformation of propionate to AA [98]. However, the less stability of anaerobic cells under an aerobic environment resulted in relatively low
yield of AA (up to 18%). In 1990, the same group used sweet whey as an initial
substrate for acrylate production in a two-step process [99]. In the first step, sweet
whey was converted to propionic acid and acetic acid in 70 h by a co-culture of
Lactobacillus bulgaricus and Propionibacterium shermanii. In the second step, propionate was converted into acrylate by resting cells of Clostridium propionicum. In
this process, maximum acrylate of 0.133 mmol g
−1
AA was produced in 6 h. When
Clostridium propionicum was grown on bio-based LA, and provided with methylene blue as an electron acceptor, it produced 144 mg L
−1
AA [97]. It was found that
K. Avasthi et al.