Study of high saline adaptation mechanisms for Halomonas beimenensis and Virgibacillus chiguensis
| Autor: | Yan-Huey Chen, 陳彥惠 |
|---|---|
| Rok vydání: | 2017 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 106 According to the characterization of high saline adaptation, halotolerant bacteria become a coming star for industrial biotechnology in recent years. Because property of tolerance in extreme environment, halotolerant bacteria become a highly regarded biology in academia and industry. Through the comprehension of halotolerance mechanism, halotolerant bacteria might help the development of the biotechnology, medical industry, and food processing industry. In fruit and vegetable processing, the halotolerance ability of microorganism might lead new product creating, processing acceleration and contamination reduction. However, there is lack of sufficient genomic information for halotolerance study in bacteria. Here, we describe the possible molecular mechanisms of saline adaptation based on high-throughput omics in two halotolerant bacteria, Halomonas beimenensis and Virgibacillus chiguensis which could grow in the environment with 20% NaCl. The complete genome of H. beimenensis genome is 4.05 Mbp with 3,807 genes, while the draft genome of V. chiguensis genome is approximately 4.15 Mbp in length with 4,347 genes. In general, many genes involved in the function of “cell motility” and “inorganic ion transport and metabolism” are up-regulated; and many genes involved in the function of “energy production and conversion”, “amino acid transport and metabolism”, “lipid transport and metabolism”, and “transcription” are down-regulated in H. beimenensis and V. chiguensis under high-salinity environment. Moreover, sixteen genes are identified as halotolerance related genes with the loss of halotolerance ability in H. beimenensis Tn5 mutants. Orthologs of genes such as nqrA, trkA, atpC, nadA, and gdhB have significant biological functions in the well know halotolerance control of sodium efflux, potassium uptake, hydrogen ion transport for energy conversion, and compatible solute synthesis. Other genes, such as spoT, prkA, mtnN, rsbV, lon, smpB, rfbC, rfbP, tatB, acrR, and lacA, also shown critical functions for promoting a halotolerance in cellular signaling, quorum sensing, transcription/translation, and cell motility. Eight out of these sixteen orthologous halotolerance related genes, such as trkA2, smpB, nadA, mtnN2, rfbP, spoT, lon, and atpC, were conserved in V. chiguensis and shown the similar expression pattern with H. beimenensis under high saline condition. This result pointed out that these 8 genes might have conserved functions in different phyla. In addition, the additional KCl could increase halotolerance and potassium-dependent cell motility of H. beimenensis under high saline environment. Our results demonstrated that through the combination of genomic and transcriptomic profiles or the combination of omics data could be facilitated the high saline adaptation mechanism exploitation. Furthermore, the sufficient bioinformation also provide an important information for potential halotolerance enzyme mining and plays a forward-looking role in genetic tools development. Finally, the 8 conserved genes can be used as molecular markers for halotolerant bacteria identification. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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