Study on breeding of l - tryptophan - producing strain and its fermentation conditions 色氨酸生產(chǎn)菌的選育及其發(fā)酵條件的研究
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 色氨酸是一種重要的中性必需氨基酸,在消化過程中,通過蛋白水解作用酶的運(yùn)動而由蛋白質(zhì)形成。
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?環(huán)糊精與芳香族氨基酸l ?苯丙氨酸、 l ?酪氨酸和l ?色氨酸之間的包合作用,考察了?環(huán)糊精用量、溫度、時間和ph值等因素對包合作用的影響。
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誘導(dǎo)表達(dá)實(shí)驗(yàn)結(jié)果表明:利用t7啟動子在胞內(nèi)能表達(dá)出有活性的酶; iptg與溫度的合適組合可以得到較高活性的色氨酸酶,在0 . 2mm以下濃度的iptg誘導(dǎo)時, 37是最適溫度,而用較高濃度的iptg誘導(dǎo),低溫是表達(dá)有活性的色氨酸酶的必要條件,而且誘導(dǎo)時間要短。