Abstract
This study was conducted to identify the optimum pH range and the appropriate buffer for butyric acid production from rice straw by fermentation using an undefined mixed culture. A series of experiments conducted at pH levels of 5.0 ~ 7.0 showed that neutral pH improved rice straw conversion and consequently carboxylic acid production. The highest butyric acid production (up to 6.7 g/L) was achieved at pH of 6.0 ~ 6.5, while it was only 1.7 g/L without pH control or at pH 5.0. Another series of experiments conducted at pH 6.0 ~ 6.5 buffered with CaCO3, NaHCO3, NH4HCO3 and their combinations indicated that different buffers had different effects onthe product spectrum, and that CaCO3 combined with NaHCO3 was an effective buffer for butyric acid production. The highest total volatile fatty acids (about 12.6 g/L) production and one of the two highest butyric acid concentrations (about 7.6 g/L) were obtained by buffering with CaCO3 combined with NaHCO3. PCR-DGGE analysis revealed that different pH and buffers also influenced the microbial population distribution. Bacteria were suppressed at low pH, while the bacterial community structures at higher pH varied slightly. Overall, this study presents an alternative method for butyric acid production from lignocellulosic biomass without supplementary cellulolytic enzyme.
Similar content being viewed by others
References
Zhang, C., H. Yang, F. Yang, and Y. Ma (2009) Current progress on butyric acid production by fermentation. Curr. Microbiol. 59: 656–663.
Al-Shorgani, N., E. Ali, M. Kalil, and W. Yusoff (2012) Bioconversion of butyric acid to butanol by Clostridium saccharoperbutylacetonicum N1-4 (ATCC 13564) in a limited nutrient medium. BioEnerg. Res. 5: 287–293.
Richter, H., N. Qureshi, S. Heger, B. Dien, M. A. Cotta, and L. T. Angenent (2012) Prolonged conversion of n-butyrate to nbutanol with Clostridium saccharoperbutylacetonicum in a twostage continuous culture with in-situ product removal. Biotechnol. Bioeng. 109: 913–921.
Dwidar, M., J.-Y. Park, R. J. Mitchell, and B.-I. Sang (2012) The future of butyric acid in industry. Sci. World J. 2012: 1–9.
Huang, Y. L., Z. Wu, L. Zhang, C. M. Cheung, and S.-T. Yang (2002) Production of carboxylic acids from hydrolyzed corn meal by immobilized cell fermentation in a fibrous-bed bioreactor. Bioresour. Technol. 82: 51–59.
Jiang, L., J. Wang, S. Liang, X. Wang, P. Cen, and Z. Xu (2009) Butyric acid fermentation in a fibrous bed bioreactor with immobilized Clostridium tyrobutyricum from cane molasses. Bioresour. Technol. 100: 3403–3409.
Zhu, Y., Z. Wu, and S.-T. Yang (2002) Butyric acid production from acid hydrolysate of corn fibre by Clostridium tyrobutyricum in a fibrous-bed bioreactor. Proc. Biochem. 38: 657–666.
Huang, J., J. Cai, J. Wang, X. Zhu, L. Huang, S.-T. Yang, and Z. Xu (2011) Efficient production of butyric acid from Jerusalem artichoke by immobilized Clostridium tyrobutyricum in a fibrous-bed bioreactor. Bioresour. Technol. 102: 3923–3926.
Zigová, J. and E. Šturdík (2000) Advances in biotechnological production of butyric acid. J. Ind. Microbiol. Biotechnol. 24: 153–160.
Agler, M. T., B. A. Wrenn, S. H. Zinder, and L. T. Angenent (2011) Waste to bioproduct conversion with undefined mixed cultures: The carboxylate platform. Trends Biotechnol. 29: 70–78.
Chang, H., N.-J. Kim, J. Kang, and C. Jeong (2010) Biomassderived volatile fatty acid platform for fuels and chemicals. Biotechnol. Bioproc. Eng. 15: 1–10.
Kleerebezem, R. and M. C. M. van Loosdrecht (2007) Mixed culture biotechnology for bioenergy production. Curr. Opin. Biotechnol. 18: 207–212.
Fu, Z. and M. T. Holtzapple (2010) Anaerobic mixed-culture fermentation of aqueous ammonia-treated sugarcane bagasse in consolidated bioprocessing. Biotechnol. Bioeng. 106: 216–227.
Holtzapple, M. and C. Granda (2009) Carboxylate platform: The MixAlco Process Part 1: Comparison of three biomass conversion platforms. Appl. Biochem. Biotechnol. 156: 95–106.
Chan, W. N., Z. Fu, and M. T. Holtzapple (2011) Co-digestion of swine manure and corn stover for bioenergy production in Mix- Alco consolidated bioprocessing. Biomass Bioenerg. 35: 4134–4144.
BinLing, A., L. JianZheng, S. JunLing, C. Xue, M. Jia, Z. LiGuo, and B. QiaoYing (2013) Butyric acid fermentation from rice straw with undefined mixed culture: Enrichment and selection of cellulolytic butyrate-producing microbial community. Internat. J. Agricult. Biol. 15: 1075–1082.
Chen, Y., S. Jiang, H. Yuan, Q. Zhou, and G. Gu (2007) Hydrolysis and acidification of waste activated sludge at different pHs. Water Res. 41: 683–689.
Zhang, B., L. L. Zhang, S. C. Zhang, H. Z. Shi, and W. M. Cai (2005) The Influence of pH on hydrolysis and acidogenesis of kitchen wastes in two-phase anaerobic digestion. Environ. Technol. 26: 329–340.
Hu, Z.-H., G. Wang, and H.-Q. Yu (2004) Anaerobic degradation of cellulose by rumen microorganisms at various pH values. Biochem. Eng. J. 21: 59–62.
Cysneiros, D., C. J. Banks, S. Heaven, and K.-A. G. Karatzas (2012) The effect of pH control and ‘hydraulic flush’ on hydrolysis and Volatile Fatty Acids (VFA) production and profile in anaerobic leach bed reactors digesting a high solids content substrate. Bioresour. Technol. 123: 263–271.
Horiuchi, J. I., T. Shimizu, K. Tada, T. Kanno, and M. Kobayashi (2002) Selective production of organic acids in anaerobic acid reactor by pH control. Bioresour. Technol. 82: 209–213.
Li, C. and H. H. P. Fang (2007) Fermentative hydrogen production from wastewater and solid wastes by mixed cultures. Crit. Rev. Environ. Sci. Technol. 37: 1–39.
Temudo, M., G. Muyzer, R. Kleerebezem, and M. van Loosdrecht (2008) Diversity of microbial communities in open mixed culture fermentations: Impact of the pH and carbon source. Appl. Microbiol. Biotechnol. 80: 1121–1130.
Kim, I. S., M. H. Hwang, N. J. Jang, S. H. Hyun, and S. T. Lee (2004) Effect of low pH on the activity of hydrogen utilizing methanogen in bio-hydrogen process. Int. J. Hydrogen Energy. 29: 1133–1140.
Russell, J. (1992) Another explanation for the toxicity of fermentation acids at low pH: Anion accumulation versus uncoupling. J. Appl. Microbiol. 73: 363–370.
Zhu, H., W. Parker, R. Basnar, A. Proracki, P. Falletta, M. Béland, and P. Seto (2009) Buffer requirements for enhanced hydrogen production in acidogenic digestion of food wastes. Bioresour. Technol. 100: 5097–5102.
Selvam, A., S. Y. Xu, X. Y. Gu, and J. W. C. Wong (2010) Food waste decomposition in leachbed reactor: Role of neutralizing solutions on the leachate quality. Bioresour. Technol. 101: 1707–1714.
Smith, A. D. and M. T. Holtzapple (2010) Investigation of nutrient feeding strategies in a countercurrent mixed-acid multi-staged fermentation: Development of segregated-nitrogen model. Bioresour. Technol. 101: 9700–9709.
Fu, Z. and M. T. Holtzapple (2010) Consolidated bioprocessing of sugarcane bagasse and chicken manure to ammonium carboxylates by a mixed culture of marine microorganisms. Bioresour. Technol. 101: 2825–2836.
Van Soest, P. J., J. Robertson, and B. Lewis (1991) Methods for dietary fiber, neutral detergent fiber, and nonstarch polysaccharides in relation to animal nutrition. J. Dairy Sci. 74: 3583–3597.
Guo, P., X. Wang, W. Zhu, H. Yang, X. Cheng, and Z. Cui (2008) Degradation of corn stalk by the composite microbial system of MC1. J. Environ. Sci. 20: 109–114.
Morikawa, Y., M. Kawamori, Y. Ado, Y. Shinsha, F. Oda, and S. Takasawa (1985) Improvement of cellulase production in Trichoderma reesei. Agric. Biol. Chem. 49: 1869–1871.
Fu, Z. and M. Holtzapple (2011) Anaerobic thermophilic fermentation for carboxylic acid production from in-storage air-limetreated sugarcane bagasse. Appl. Microbiol. Biotechnol. 90: 1669–1679.
Nachiappan, B., Z. Fu, and M. T. Holtzapple (2011) Ammonium carboxylate production from sugarcane trash using long-term airlime pretreatment followed by mixed-culture fermentation. Bioresour. Technol. 102: 4210–4217.
Thanakoses, P., N. Mostafa, and M. Holtzapple (2003) Conversion of sugarcane bagasse to carboxylic acids using a mixed culture of mesophilic microorganisms. Appl. Biochem. Biotechnol. 107: 523–546.
Kayhanian, M. (1999) Ammonia inhibition in high-solids biogasification: An overview and practical solutions. Environ. Technol. 20: 355–365.
Forrest, A. K., R. Sierra, and M. T. Holtzapple (2010) Suitability of pineapple, Aloe vera, molasses, glycerol, and office paper as substrates in the MixAlco process. Biomass Bioenerg. 34: 1195–1200.
Agbogbo, F. K. and M. T. Holtzapple (2007) Fixed-bed fermentation of rice straw and chicken manure using a mixed culture of marine mesophilic microorganisms. Bioresour. Technol. 98: 1586–1595.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Ai, B., Li, J., Chi, X. et al. Effect of pH and buffer on butyric acid production and microbial community characteristics in bioconversion of rice straw with undefined mixed culture. Biotechnol Bioproc E 19, 676–686 (2014). https://doi.org/10.1007/s12257-013-0655-z
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s12257-013-0655-z