Table 3.

Classification of process and products of biological conversion pathways.

S. No	Reactants (Molar ratio)	Pathway	Catalyst	Optimal Reaction Condition(s)	Product (s) -yield	Reference
1.	Glycerol	Fermentation	Escherichia coli AC-521	42 ◦C,pH-6.5, 88 hour	Lactic acid - 85.8 g/L	[25]
2.	Crude glycerol	Fermentation	G. Oxydans cells immobilised over polyurethane foam	31 °C, glycerol concentration – 20 g/L, pH – 4.7	1,3-Dihydroxyacetone - 17.83 g/L	[26]
3.	Glycerol	Fermentation	Gluconacetobacter xylinus cells	25(w/v), 60 hour, 30 ◦C, pH - 6	Dihydroxyacetone -6.3 g/L	[30]
4.	Glycerol	Fermentation	Rhodosporidium toruloides	30−60 hour, C/N ratio – 300	Lipids	[32]
5.	Pure and recovered glycerol	Ferementation	Enterobacter aerogenes	Glycerol conc. – 39 g/L, 120 hour, pH - 7	Ethanol – 20 g/L	[33]
6.	Glycerol	Anaerobic batch fermentation	Escherichia coli SS1	37 °C,96 hour, glycerol conc. – 20 g/L	Bioethanol (ethyl alcohol) – 9.23 g/L	[34]
7.	Crude glycerol and crustacean waste	Fermentation	Yarrowia lipolytica	30 °C,pH – 6	Lipase	[35]
8.	Glycerol	Batch fermentation	Clostridium butyricum DSP1	37 ◦C, pH- 7, 140 g/L	1,3-propandiol – 67 g/L	[36]
9.	Crude glycerol	Fermentation	Schizochytrium limacinum	19.2 ◦C,100 g/L	Docosahexaenoic acid (DHA) – 4.91 /L	[37]