Influence of pH for Synthesis and Degrading of Polylysine

• Main Authors: HO,CHIA-YEN, 何佳彥
• Other Authors: WU,FANG-CHEN
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/nj26ac

碩士 === 大葉大學 === 生物產業科技學系 === 106 === Polylysine (PL) is a small group of polyamides that consists of only one type of amino acid in nature. It is water soluble, edible, and biodegradable, and therefore of interest to the food and pharmaceutical industry. Recently, biosynthesis mechanism of PL in the production has been extensively investigated. In this study, the effect of M3G media with different pH–4.8, 5.8, and 6.8 using Streptomyces albulus BCRC 11814 cultured at 30±2 °C for 6 days was examined with mechanism of PL production. The results showed that cultural pH value of different pH media were kept lower than 5.0 after 4 days, a condition which favored the production of polymer. The pH value of samples–pH 4.8 culture broth were maintained without significantly different throughout the cultivation after 6 days. The samples of media with same pH value during cultivation kept constant amount of extracellular PL and then there was not significant variation. Besides, the results of protein analysis showed that the samples of pH 4.8 media had more significantly extracellular protein content than those of intracellular protein. On the other hand, the samples of pH 6.8 media had higher quantity of intracellular protein than those of extracellular protein. The samples of pH 5.8 media at first had higher intracellular protein content than those of extracellular protein. Both intracellular and extracellular samples were close to amount of protein during days 3 and 4. Extracellular protein content finally higher than intracellular protein content. Using SDS-PAGE and GFC analysis, we figured out that there were degrading enzyme in samples of pH 4.8 media cultured 1.5 days and those of pH 6.8 cultured 2 days, and synthetase in samples of pH 5.8 media cultured for 1.5 days.