Study on breeding of l - tryptophan - producing strain and its fermentation conditions 色氨酸生产菌的选育及其发酵条件的研究
2.
L - tryptophan is a neutral , genetically coded amino acid . iit is essential in human nutrition . formed from proteins during the digestive process by the action of proteolytic enzymes 色氨酸是一种重要的中性必需氨基酸，在消化过程中，通过蛋白水解作用酶的运动而由蛋白质形成。
3.
The inclusion behaviors of b - cyclodextrin with some aromatic amino acids such as l - phenylalanine , l - tyrosine and l - tryptophan were studied via ultraviolet and fluorescent spectrometry . the results indicated that inclusion complexes of - cyclodextrin with aromatic amino acids could be formed and the inclusion behaviors were affected by the amount of - cyclodextrin , temperature and ph value 本文研究了?环糊精与芳香族氨基酸l ?苯丙氨酸、 l ?酪氨酸和l ?色氨酸之间的包合作用，考察了?环糊精用量、温度、时间和ph值等因素对包合作用的影响。
4.
Induced either by iptg or l - tryptophan in the absence of easily metabolized carbon such as glucose the strain bl21 ( de3 ) / pet28c - tnaa can express tryptopanase . the fermentation conditions were optimized respectively . in the presence of glucose and iptg as induce agent , the concentration is the crucial factor for expression of active tryptophanase . if the iptg concentration is less than 0 . 2mm , the optimum temperature is 37 lower temperature is necessary to obtain active tryptophanase in the case of higher concentration of iptg 用iptg诱导表达实验结果表明：利用t7启动子在胞内能表达出有活性的酶； iptg与温度的合适组合可以得到较高活性的色氨酸酶，在0 . 2mm以下浓度的iptg诱导时， 37是最适温度，而用较高浓度的iptg诱导，低温是表达有活性的色氨酸酶的必要条件，而且诱导时间要短。
