Evaluation of the Fermentation Potential of Pulp Mill Residue to Produce d(−)-Lactic Acid by Separate Hydrolysis and Fermentation Using Lactobacillus coryniformis subsp. torquens
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Lactic acid is widely used in chemical, pharmaceutical, cosmetic, and food industries, besides it is the building block to produce polylactic acid, which is a sustainable alternative biopolymer to synthetic plastic due to its biodegradability. Aiming at producing an optically pure isomer, the present work evaluated the potential of pulp mill residue as feedstock to produce d(−)-lactic acid by a strain of the bacterium Lactobacillus coryniformis subsp. torquens using separate hydrolysis and fermentation process. Enzymatic hydrolysis, optimized through response surface methodology for 1 g:4 mL solid/liquid ratio and 24.8 FPU/gcellulose enzyme loading, resulted in 140 g L−1 total reducing sugar and 110 g L−1 glucose after 48 h, leading to 61 % of efficiency. In instrumented bioreactor, 57 g L−1 of d(−)-lactic acid was achieved in 20 h of fermentation, while only 0.5 g L−1 of l(+)-lactic acid was generated. Furthermore, product yield of 0.97 g/g and volumetric productivity of 2.8 g L−1 h−1 were obtained.
KeywordsPulp mill residue Separate hydrolysis and fermentation Enzymatic hydrolysis d(−)-lactic acid Lactobacillus coryniformis subsp. torquens
The authors would like to thank the colleagues of LADEBIO/EQ/UFRJ for all technical support during the experiments and the AGIR/UFF for PIBITI scholarship.
- 2.Oshiro, M., Shinto, H., Tashiro, Y., Miwa, N., Sekiguchi, T., Okamoto, M., & Sonomoto, K. (2009). Kinetic modeling and sensitivity analysis of xylose metabolism in Lactococcus lactis IO-1. Journal of Bioscience and Bioengineering, 108, 376–384. doi: 10.1016/j.jbiosc.2009.05.003.CrossRefGoogle Scholar
- 10.Werpy, T., & Petersen, G. (2004). Top value added chemicals from biomass: volume I—results of screening for potential candidates from sugars and synthesis gas. United States: U.S. Department of Energy—Energy Efficiency and Renewable Energy.Google Scholar
- 11.Okano, K., Tanaka, T., Ogino, C., Fukuda, H., & Kondo, A. (2010). Biotechnological production of enantiomeric pure lactic acid from renewable resources: recent achievements, perspectives, and limits. Applied Microbiology and Biotechnology, 85, 413–423. doi: 10.1007/s00253-009-2280-5.CrossRefGoogle Scholar
- 14.Silva, N. L. C., Betancur, G. J. V., Vásquez, M. P., Gomes, E. B., & Pereira Jr., N. (2011). Ethanol production from residual wood chips of cellulose industry: acid pretreatment investigation, hemicellulosic hydrolysate fermentation, and remaining solid fraction fermentation by SSF process. Applied Biochemistry and Biotechnology, 163, 928–936. doi: 10.1007/s12010-010-9096-8.CrossRefGoogle Scholar
- 15.González-Vara, A., Pinelli, D., Rossi, M., Fajner, D., Magelli, F., & Matteuzzi, D. (1996). Production of L(+) and D(−) lactic acid isomers by Lactobacillus casei subsp. casei DSM 20011 and Lactobacillus coryniformis subsp. torquens DSM 20004 in continuous fermentation. Journal of Fermentation and Bioengineering, 81, 548–552.CrossRefGoogle Scholar