{"title":"Ethyl Methane Sulfonate-Induced Dunaliella salina KU11 Mutants Affected for Growth Rate, Cell Accumulation and Biomass","authors":"Vongsathorn Ngampuak, Yutachai Chookaew, Wipawee Dejtisakdi","volume":115,"journal":"International Journal of Bioengineering and Life Sciences","pagesStart":430,"pagesEnd":435,"ISSN":"1307-6892","URL":"https:\/\/publications.waset.org\/pdf\/10004961","abstract":"
Dunaliella salina<\/em> has great potential as a system for generating commercially valuable products, including beta-carotene, pharmaceuticals, and biofuels. Our goal is to improve this potential by enhancing growth rate and other properties of D. salina<\/em> under optimal growth conditions. We used ethyl methane sulfonate (EMS) to generate random mutants in D. salina <\/em>KU11, a strain classified in Thailand. In a preliminary experiment, we first treated D. salina<\/em> cells with 0%, 0.8%, 1.0%, 1.2%, 1.44% and 1.66% EMS to generate a killing curve. After that, we randomly picked 30 candidates from approximately 300 isolated survivor colonies from the 1.44% EMS treatment (which permitted 30% survival) as an initial test of the mutant screen. Among the 30 survivor lines, we found that 2 strains (mutant #17 and #24) had significantly improved growth rates and cell number accumulation at stationary phase approximately up to 1.8 and 1.45 fold, respectively, 2 strains (mutant #6 and #23) had significantly decreased growth rates and cell number accumulation at stationary phase approximately down to 1.4 and 1.35 fold, respectively, while 26 of 30 lines had similar growth rates compared with the wild type control. We also analyzed cell size for each strain and found there was no significant difference comparing all mutants with the wild type. In addition, mutant #24 had shown an increase of biomass accumulation approximately 1.65 fold compared with the wild type strain on day 5 that was entering early stationary phase. From these preliminary results, it could be feasible to identify D. salina<\/em> mutants with significant improved growth rate, cell accumulation and biomass production compared to the wild type for the further study; this makes it possible to improve this microorganism as a platform for biotechnology application.<\/p>\r\n","references":"[1]\tK. E. Apt and P. W. Behrens, \u201cCommercial developments in microalgal biotechnology,\u201d J. Phycol., vol. 35, no. 2, pp. 215\u2013226, Apr. 1999.\r\n[2]\tW. Becker and A. Richmond, \u201cMicroalgae for aquaculture: the nutritional value of microalgae for \taquaculture.,\u201d pp. 380\u2013391, 2004.\r\n[3]\tQ. Hu, M. Sommerfeld, E. Jarvis, M. Ghirardi, M. Posewitz, M. Seibert, and A. Darzins, \u201cMicroalgal \ttriacylglycerols as feedstocks for biofuel production: perspectives and advances.,\u201d Plant J., vol. 54, no. 4, pp. 621\u201339, May 2008.\r\n[4]\tR. Raja, S. Hemaiswarya, N. A. Kumar, S. Sridhar, and R. Rengasamy, \u201cA Perspective on the Biotechnological Potential of Microalgae,\u201d Crit. Rev. Microbiol., vol. 34, no. 2, pp. 77\u201388, Jan. 2008.\r\n[5]\tA. Martins, N. S. Caetano, and T. M. Mata, \u201cMicroalgae for biodiesel production and other applications: A review,\u201d vol. 14, pp. 217\u2013232, 2010.\r\n[6]\tY. Gong, H. Hu, Y. Gao, X. Xu, and H. Gao, \u201cMicroalgae as platforms for production of recombinant proteins and valuable compounds: progress and prospects.,\u201d J. Ind. Microbiol. Biotechnol., vol. 38, no. 12, pp. 1879\u201390, Dec. 2011.\r\n[7]\tR. Sathasivam, N. Juntawong, and B. Program, \u201cModified medium for enhanced growth of Dunaliella \tstrains,\u201d pp. 67\u201373, 2013.\r\n[8]\tZ. Wu, P. Duangmanee, P. Zhao, N. Juntawong, and C. Ma, \u201cThe Effects of Light, Temperature, and Nutrition on Growth and Pigment Accumulation of Three Dunaliella salina Strains Isolated from Saline Soil.,\u201d Jundishapur J. Microbiol., vol. 9, no. 1, p. e26732, Jan. 2016.\r\n[9]\tM. Schroda, D. Bl\u00f6cker, and C. F. Beck, \u201cThe HSP70A promoter as a tool for the improved expression of transgenes in Chlamydomonas.,\u201d Plant J., vol. 21, no. 2, pp. 121\u201331, Jan. 2000.\r\n[10]\tT. Wang, L. Xue, W. Hou, B. Yang, Y. Chai, X. Ji, and Y. Wang, \u201cIncreased expression of transgene in stably transformed cells of Dunaliella salina by matrix attachment regions.,\u201d Appl. Microbiol. Biotechnol., vol. 76, no. 3, pp. 651\u20137, Sep. 2007.\r\n[11]\tR. P. Sinha and D.-P. H\u00e4der, \u201cUV-induced DNA damage and repair: a review,\u201d Photochem. Photobiol. Sci., vol. 1, \tno. 4, pp. 225\u2013236, Apr. 2002.\r\n[12]\tY. Kim, K. S. Schumaker, and J.-K. Zhu, \u201cEMS mutagenesis of Arabidopsis.,\u201d Methods Mol. Biol., vol. 323, no. 6, pp. 101\u20133, Jan. 2006.\r\n[13]\tM. Hlavova, Z. Turoczy, and K. Bisova, \u201cImproving microalgae for biotechnology \u2014 From genetics to synthetic biology,\u201d Biotechnol. Adv., vol. 33, no. 6, pp. 1194\u20131203, 2015.\r\n[14]\tB. Lee, G.-G. Choi, Y.-E. Choi, M. Sung, M. S. Park, and J.-W. Yang, \u201cEnhancement of lipid productivity by ethyl methane sulfonate-mediated random mutagenesis and proteomic analysis in Chlamydomonas reinhardtii,\u201d Korean J. Chem. Eng., vol. 31, no. 6, pp. 1036\u20131042, Jun. 2014.\r\n[15]\tR. Radakovits, R. E. Jinkerson, A. Darzins, and M. C. Posewitz, \u201cGenetic engineering of algae for enhanced biofuel production.,\u201d Eukaryot. Cell, vol. 9, no. 4, pp. 486\u2013501, Apr. 2010.\r\n[16]\tF. Ahmed, K. Fanning, M. Netzel, and P. M. Schenk, \u201cInduced carotenoid accumulation in Dunaliella salina and Tetraselmis suecica by plant hormones and UV-C radiation.,\u201d Appl. Microbiol. Biotechnol., vol. 99, no. 22, pp. 9407\u201316, Nov. 2015.\r\n[17]\tH. Mendoza, A. de la Jara, K. Freijanes, L. Carmona, A. \tA. Ramos, V. de Sousa Duarte, and J. C. Serafim Varela, \u201cCharacterization of Dunaliella salina strains by flow cytometry: a new approach to select carotenoid hyperproducing strains,\u201d Electron. J. Biotechnol., vol. 11, \t\tno. 4, Oct. 2008.\r\n[18]\tB. Sandesh Kamath, R. Vidhyavathi, R. Sarada, and G. A. Ravishankar, \u201cEnhancement of carotenoids by mutation and stress induced carotenogenic genes in Haematococcus pluvialis mutants,\u201d Bioresour. Technol., vol. 99, no. 18, pp. 8667\u20138673, 2008.\r\n[19]\tV. H. Work, R. Radakovits, R. E. Jinkerson, J. E. Meuser, L. G. Elliott, D. J. Vinyard, L. M. L. Laurens, G. C. Dismukes, and M. C. Posewitz, \u201cIncreased lipid accumulation in the Chlamydomonas reinhardtii sta7-10 \tstarchless isoamylase mutant and increased carbohydrate synthesis in complemented strains.,\u201d Eukaryot. Cell, vol. \t9, no. 8, pp. 1251\u201361, Aug. 2010.\r\n[20]\tM. Mobini-Dehkordi, I. Nahvi, H. Zarkesh-Esfahani, K. Ghaedi, M. Tavassoli, and R. Akada, \u201cIsolation of a novel mutant strain of Saccharomyces cerevisiae by an ethyl methane sulfonate-induced mutagenesis approach \tas a high producer of bioethanol,\u201d J. Biosci. Bioeng., vol. 105, no. 4, pp. 403\u2013408, 2008.\r\n[21]\tM. H. Huesemann, T. S. Hausmann, R. Bartha, M. Aksoy, J. C. Weissman, and J. R. Benemann, \u201cBiomass productivities in wild type and pigment mutant of Cyclotella sp. (Diatom).,\u201d Appl. Biochem. Biotechnol., \tvol. 157, no. 3, pp. 507\u201326, Jun. 2009.\r\n[22]\tA. Hosseini Tafreshi and M. Shariati, \u201cDunaliella biotechnology: Methods and applications,\u201d J. Appl. Microbiol., vol. 107, no. 1, pp. 14\u201335, 2009.","publisher":"World Academy of Science, Engineering and Technology","index":"Open Science Index 115, 2016"}