Effect of Acid Species on <i>Cryptococcus</i> sp. T1 and Construction of Its Bioreactor System for Continuous Neutralization of Acidic Media
- 1 Department of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan
- 2 Department of Ocean Science, Laboratory of Marine Biochemistry, Tokyo University of Marine Science and Technology, Tokyo, Japan
- 3 Department of Ocean Science, Laboratory of Marine Biochemistry, Tokyo University of Marine Science and Technology, Tokyo, Japan
- 4 Department of Ocean Science, Laboratory of Marine Biochemistry, Tokyo University of Marine Science and Technology, Tokyo, Japan
- 5 Department of Ocean Science, Laboratory of Marine Biochemistry, Tokyo University of Marine Science and Technology, Tokyo, Japan
- 6 Department of Ocean Science, Laboratory of Marine Biochemistry, Tokyo University of Marine Science and Technology, Tokyo, Japan
Abstract
Generally, the tolerance of yeasts to acid is stronger than that of bacteria. In addition, some of the yeasts are able to neutralize acidic media, which is called acid-neutralizing yeast. An acid-neutralizing yeast, Cryptococcus sp. strain T1, was previously isolated from Lake Tazawa in Japan. Here we investigated the effect of several types of acid on the neutralizing ability of strain T1, and we improved an existing bioreactor model to effectively neutralize acidic water. First we carried out a neutralizing test with strain T1 using casamino acid solution adjusted to pH 3.0 - 5.0 with each inorganic or organic acid. The solutions adjusted to pH 3.0 with nitric acid, phosphoric acid, sulfuric acid, and citric acid were neutralized by strain T1. The pH 3.0 solutions with lactic acid, formic acid, and acetic acid were not neutralized. These results demonstrated that some types of organic acid avoid neutralization by strain T1, and we hypothesized that this might be due to the sterilizing function of non-dissociative organic acid. We then constructed a bioreactor system with a column filled with T1-immobilized alginate beads. The previous research identified a problem in this bioreactor system: the high level of ammonium ions (NH + 4 ) in the neutralized water might pollute water environments, and aluminum ions (Al 3+ ) included in acidic water prevent the neutralization. Here, we used zeolite to get rid of the NH + 4 and Al 3+ , and the addition of a zeolite reactor enabled the bioreactor system to neutralize the acidic water with a decrease of NH + 4 in the water.
- [1] Okai, M., Suwa, C., Nagaoka, S., Obara, N., Mitsuya, D., Kurihara, A., Ishida, M. and Urano, N. (2017) Neutralization of Acidic Drainage by Cryptococcus sp. T1 Immobilized in Alginate Beads. Bioscience Biotechnology and Biochemistry, 81, 2216-2224. https://doi.org/10.1080/09168451.2017.1373586
- Park, H.J., Bae, J.H., Ko, H.J., Lee, S.H., Sung, B.H., Han, J.I. and Sohn, J.H. (2018) Low-pH Production of D-Lactic Acid Using Newly Isolated Acid Tolerant Yeast Pichia kudriavzevii NG7. Biotechnology and Bioengineering, 115, 2232-2242. https://doi.org/10.1002/bit.26745
- Nguyen, V.A.T., Senoo, K., Mishima, T. and Hisamatsu, M. (2001) Multiple Tolerance of Rhodotorula glutinis R-1 to Acid, Aluminum Ion and Manganese Ion, and Its Unusual Ability of Neutralizing Acidic Medium. Journal of Bioscience and Bioengineering, 92, 366–371. https://doi.org/10.1016/S1389-1723(01)80241-3
- Mitsuya, D., Hayashi, T., Wang, Y., Tanaka, M., Okai, M., Ishida, M. and Urano, N. (2017) Isolation of Aquatic Yeasts with the Ability to Neutralize Acidic Media, from an Extremely Acidic River near Japan’s Kusatsu-Shirane Volcano. Journal of Bioscience and Bioengineering, 124, 43-46. https://doi.org/10.1016/j.jbiosc.2017.02.005
- Nagaoka S., Kobayashi T., Kajiwara Y., Okai M., Ishida M. and Urano N. (2017) Characterization of Yeasts Capable of Neutralizing Acidic Media from Natural Neutral Environments. Advances in Microbiology, 7, 887-897. https://doi.org/10.4236/aim.2017.712068
- Walter A. and Gutknecht J. (1984) Monocarboxylic Acid Permeation through Lipid Bilayer Membranes. The Journal of Membrane Biology, 77, 255-264. https://doi.org/10.1007/BF01870573
- Poole, R.C. and Halestrap, A.P. (1993) Transport of Lactate and Other Monocarboxylates across Mammaian Plasma Membranes. American Journal of Physiology-Cell Physiology, 264, C761-C782. https://doi.org/10.1152/ajpcell.1993.264.4.C761
- Narendranath, N.V., Thomas, K.C. and Ingledew, W.M. (2001) Effects of Acetic Acid and Lactic Acid on the Growth of Saccharomyces cerevisiae in a Minimal Medium. Journal of Industrial Microbiology and Biotechnology, 26, 171-177. https://doi.org/10.1038/sj.jim.7000090
- Ludovico, P., Sousa, M.J., Silva, M.T., Leão, C. and Côrte-Real, M. (2001) Saccharomyces cerevisiae Commits to a Programmed Cell Death Process in Response to Acetic Acid. Microbiology, 147, 2409-2415. https://doi.org/10.1099/00221287-147-9-2409
- Warnecke, T. and Gill, R.T. (2005) Organic Acid Toxicity, Tolerance, and Production in Escherichia coli Biorefining Applications. Microbial Cell Factories, 4, 25. https://doi.org/10.1186/1475-2859-4-25