Fermentative strategies for microbial production of a series of poly-(3-hydroxyalkanoates)

• Main Authors: Chih-Ying Fang, 方智穎
• Other Authors: 魏毓宏
• Format: Others
• Language: zh-TW
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/58437605206255106374

碩士 === 元智大學 === 生物科技暨生物資訊研究所 === 94 === In this study we used Cupriavidus taiwanensis, Burkholderia sp. a series of nodule bacteria of native country, recombined E. coli and Pseudomonas putida KT2442 to produce a series of biodegradable polymer, Polyhydroxyalkanoate (PHA), included short chain length PHA (scl-PHA) and medium chain length (mcl-PHA). By Sudan Black B stain technique to determine which strain had a potential to produced PHA and used Gas chromatography (GC) to analyzed kinds of PHA. Cupriavidus taiwanensis 184 and Burkholderia sp. PTU9 were selected had a relatively potential to produced Poly-3-hydroxybutyrate (P(3HB)). The end point of this experiment was the optimization of culture medium, growth condition and all kinds of fermentative strategies. From flask test to the application of fermentor strategies, thus the productivity of PHA would be increased. At the second stage, switched of the temperature or added additional heavy metal, actually would induce accumulation of P (3HB) in bacteria. The further study showed when growth temperature increased from 30℃ to 42℃ at the second stage, P(3HB) content would be improved from originally 37.2% to 42.5%. Secondly, added additional heavy metal, with 50μM K2Cr2O7 and 100μM CdCl2, P(3HB) content was differentiated and can be improved by 7.1%, 9.4%, enhanced to 41.3% and 43.6%, respectively. Burkholderia sp. PTU9 could get the cell dry weight enhanced to 13.51 g/L under the circumstance of the batch with limited nitrogen, its P(3HB) content reached 53.79%, P(3HB) concentration can reached 7.26 g/L. When used recombined E. coli in fed-batch fermentation strategy, could get cell dry weight up to 80.8 g/L, P(3HB) content up to 40.6%, P(3HB) concentration up to 32.8 g/L. While when use Pseudomonas putida KT2442 in fed-batch fermentation strategy, could get cell dry weight up to 36.36 g/L, PHA content can reached as high as 59.3%, included Polyhydroxyhexanoate (PHHx) 3.38%, Polyhydroxyoctanoate (PHO) 24.13%, Polyhydroxydecanoate (PHD) 22.42% and Polyhydroxydodecanoate (PHDD) 9.43%.