Khucharoenphaisan K, Sinma K
Faculty of Science and Technology, Pranakhon Rajabhat University, Bangkok 12200, Thailand.
Pak J Biol Sci. 2011 Feb 1;14(3):226-31. doi: 10.3923/pjbs.2011.226.231.
The strain PNR11 was isolated from gut of termite during the screening for uric acid degrading actinomyces. This strain was able to produce an intracellular uricase when cultured in fermentation medium containing uric acid as nitrogen source. Base on its morphological characters and 16S rDNA sequence analysis, this strain belong to the genus Saccharopolyspora. This is the first report ofuricase produced from the genus Saccharopolyspora. The aim of this study was to investigate the effects of different factors on uricase production by new source of Saccharopolyspora. Saccharopolyspora sp. PNR11 was cultured in production medium in order to determine the best cultivation period. The result showed that the time period required for maximum enzyme production was 24 h on a rotary shaker operating at 180 rpm. Optimized composition of the production medium consisted of 1% yeast extract, 1% maltose, 0.1% K2HPO4, 0.05% MgSO4 7H2O, 0.05% NaCl and 1% uric acid. The optimum pH and temperature for uricase production in the optimized medium were pH 7.0 and 30 degrees C, respectively. When the strain was cultured at optimized condition, the uricase activity reached to 216 mU mL(-1) in confidential level of 95%. The crude enzyme had an optimum temperature of uricase was 37 degrees C and it was stable up to 30 degrees C at pH 8.5. The optimum pH ofuricase was 8.5 and was stable in range of pH 7.0-10.0 at 4 degrees C. This strain might be considered as a candidate source for uricase production in the further studies. Present finding could be fulfill the information ofuricase produce from actinomycetes.
在筛选尿酸降解放线菌的过程中,从白蚁肠道中分离出菌株PNR11。当该菌株在以尿酸为氮源的发酵培养基中培养时,能够产生一种细胞内尿酸酶。基于其形态特征和16S rDNA序列分析,该菌株属于糖多孢菌属。这是关于糖多孢菌属产生尿酸酶的首次报道。本研究的目的是探究不同因素对新来源糖多孢菌产生尿酸酶的影响。培养糖多孢菌属菌株PNR11以确定最佳培养周期。结果表明,在转速为180 rpm的旋转摇床上,产生最大酶量所需的时间为24小时。生产培养基的优化组成包括1%酵母提取物、1%麦芽糖、0.1%磷酸氢二钾、0.05%七水硫酸镁、0.05%氯化钠和1%尿酸。在优化培养基中产生尿酸酶的最适pH和温度分别为pH 7.0和30℃。当该菌株在优化条件下培养时,尿酸酶活性在95%的置信水平下达到216 mU mL-1。粗酶的尿酸酶最适温度为37℃,在pH 8.5时,温度高达30℃仍稳定。尿酸酶的最适pH为8.5,在4℃时,pH在7.0 - 10.0范围内稳定。在进一步的研究中,该菌株可能被视为尿酸酶生产的候选来源。目前的发现可以补充放线菌产生尿酸酶的信息。