- 學位論文
利用本土海洋弧菌Vibrio spp. M20生產 Poly (3-hydroxybutyrate)之培養最適化
Media optimization of poly(3-hydroxybutyrate) from the indigenous marine isolate Vibrio spp. M20
若您是本文的作者，可授權文章由華藝線上圖書館中協助推廣。
摘要
一個分離自海底沉積物的海洋細菌Vibrio spp. M20，在本研究中用來評估生產生物可分解性塑膠poly(3-hydroxybutyrate，P(3HB))。本研究主要針Vibrio spp. M20量產P(3HB)，開發一最適化培養基組成與配方。研究顯示：當以甘油做為主要碳源時，P(3HB)最大含量大約可達50%。研究近一步證實：加入NaOH、NH4OH以及 NaOCl等有利於P(3HB)之純化。此外，利用NaOCl分解非PHB之細胞其他物質時，P(3HB)之含量可達38% (MGYT)；在使用NH4OH時P(3HB)之含量可達31% (MGYTT)，而最佳的萃取條件為反應時間40分鐘並且在50℃情況下。在pH值降低時，會促進P(3HB)裂解酶分解細胞內之P(3HB)，這種現象經推測，是由於加入某些無機鹽如檸檬酸鈉緩衝溶液(sodium citrate buffer)使pH值降至5.5造成P(3HB)含量下降。研究顯示：分別在MGYT中自12.3 % 降至8.2 %，而在MGYTT則自24% 降至 6%，幾乎有四倍的差異。本研究亦顯示：利用不同碳源、氮源以及氯化鈉(sodium chloride)濃度，明顯促進P(3HB)的累積，但添加無機鹽，將促使P(3HB)含量降低。
並列摘要
Vibrio spp. M20 a marine bacterium isolated from marine sediment was used to produce biodegradable polymer poly(3-hydroxybutyrate, P(3HB)). In order to enhance P(3HB) production, fascinating investigations including medium optimization, growth criteria under various conditions and fermentative strategies were carried out. A maximum P(3HB) content of about 50% were obtained when using glycerol as the sole carbon source. Gradually the extraction chemicals such as NaOH, NH4OH and NaOCl showed efficient digestion of non PHB cellular materials (NPCM). Also digestion with NaOCl results in 38% P(3HB) in MGYT media and NH4OH results in 31% (P3HB) in MGYTT media, while considering the digestion time length 40 min at 50℃ showed the best fit for extraction. Interestingly when the pH gets reduced it induces the depolymerase enzyme which results in intracellular P(3HB) degradation, this phenomenon has been speculated from adding mineral salts individually, followed by using the sodium citrate buffer at low pH 5.5 resulting in degradation of P(3HB) which leads to decrease of P(3HB) content from 12.3 % to 8.2 % in MGYT and 24% to 6% in MGYTT nearly 4 fold times. This experimental study also shows efficient carbon source, nitrogen source and sodium chloride concentration which facilitates P(3HB) accumulation. Simultaneously effect of individual addition of mineral salts on degradation of P(3HB) content has also been analyzed.
參考文獻
Chih-Ching Chien., Chang-Chieh Chen., Meng-Hui Choi., Shieh-Shiuh Kung., Yu-Hong Wei. Production of poly-beta-hydroxybutyrate (PHB) by Vibrio spp. isolated from marine environment. J Biotechnol. 3:259-63 (2007)
Matsusaki H., Abe H., Doi Y. Biosynthesis and properties of poly(3-hydroxybutyrate-co-3-hydroxyalkanoates) by recombinant strains of Pseudomonas species. Biomacromolecules. 1:17-22 (2000).
Lee S.Y., and Choi J. Effect of Fermentation Performance on the Economics of Poly-(3-hydroxybutyrate) Production by Alcaligenes latus. Polym Degrad Stab. 59:87-93 (1998).
Shilpi Khanna and Ashok K. Srivastava. Recent advances in microbial polyhydroxyalkanoates. Process Biochemistry. 40: 607-619 (2005).
Poirier Y., Nawrath C., Somerville C. Production of polyhydroxyalkanoates, a family of biodegradable plastics and elastomers in bacteria and plants. Biotechnology. 13:142-150 (1995).