Succinic acid microbial fermentation

Succinic acid is a potential platform chemical that is expected to be commercialised in a few years. Although the production capacity of petrochemically derived succinic acid is on the scale of 15 000 tonnes per year (Zeikus etal., 1999), the production capacity of succinic acid derivatives is over 270 000 tonnes per year (Willke and Vorlop, 2004). Fermentative production of succinic acid could offer a viable route to bulk chemical production. Figure 4.4 presents potential routes for chemical production from succinic acid (McKinlay et al., 2007). Another advantage of succinic acid microbial production is the simultaneous requirement for CO2 consumption, which reduces the emission of the most important greenhouse gas and makes fermentative succinic acid production a process of significantly low environmental impact. 

After sterilization, yeast is added to initiate fermentation. McConnell and Schramm (1995) recommend inoculation with no less than 10% by volume. Moreover, as the pH of honey is naturally low and because it is poorly buffered, the pH of must may drop during fermentation to a point limiting yeast efficiency. pH reduction can result from the synthesis of acetic and succinic acids by the yeast cells (Sroka and Tuszynski, 2007). While a rapid decline in pH inhibits undesirable microbial activity (Sroka and Tuszynski, 2007), it also reduces the dissociation of fatty acids in the wort, potentially slowing yeast metabolic action. For this, addition of a buffer is important to maintain the pH within a range of 3.7-4.0 throughout fermentation (McConnell and Schramm, 1995). Calcium carbonate, potassium carbonate, potassium bicarbonate, and tartaric acid are potential candidates. However, as some of these salts can add a bitter-salty... 

Succinic acid currently is manufactured by chemical processes (1). Many attempts have been made to develop a fermentation process for the production of succinic acid from renewable feedstocks such as corn-derived glucose. A number of patents have been issued on the microbial production of succinic acid (4-7). However, none of these has been applied toward the commercial production of succinic acid. 

At the present stage, petroleum- or coal-based succinic acid is still cheaper than bio-based feedstock. With future development of fermentation technology and the finding of new microbial strains, bio-based succinic acid will become competitive. 

Besides lactic acid. Dr Jun Xu opines that inaeasing demand on biodegradable poly(butylene succinate) (PBS) will open a new market for succinic acid produced via microbial fermentation. He reviews the synthesis of succinic acid, PBS polymerization, crystalline structure, thermal and mechanical properties, and biodegradability. 

Kiely et al. operated microbial fuel cells for more than a year with individual endproducts of lignocellulose fermentation (acetic add, formic add, lactic acid, succinic acid, or ethanol) to investigate the long-term cathode performance and bacterial commimities. Cathode performance degraded over time, as shown by an increase in power of up to 26% when the cathode biofihn was removed, and 118% using new cathodes [58]. For submerged air cathodes in two-chamber... 

Sugarcane bagasse Chemical and microbial Chemical treatment of the feedstock was followed by fermentation using Actmobacillus succinogenes Succinic acid Borges and Pereira Jr (2011)... 

The downstream domain of the microbial production of FA has imposed a major economical barrier to entry into commercial trade for this multifaceted organic acid. As compared to the well-established downstream strategies for different fermented organic acids such as lactic acid, succinic acid, and citric acid, separation techniques for FA from the fermented broth have not met the conditions for scaling up in both economical and technical aspects. 

Song, H., Lee, S.Y., 2006. Production of succinic acid by bacterial fermentation. Enzyme and Microbial Technology 39(3), 352-361. 

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