中文摘要：

金橙黄微小杆菌ATCC49676具有巨大的产乳酸潜力.为筛查可能影响或调节乳酸产量的代谢物,研究首先通过全因子实验设计优化并确定了最大乳酸产量的培养基组成.然后,通过气相色谱质谱联用技术对在基础培养基和优化培养基培养条件下的培养物进行代谢指纹分析.显著性分析发现,两种培养条件下胞内的谷氨酸变化最为显著.当ATCC49676在外加谷氨酸培养时,乳酸的产量随着谷氨酸浓度的增加而下降.相对酶定量证实了谷氨酸可降低胞内乳酸脱氢酶含量.研究证实了代谢指纹分析在探究表型特异性胞内代谢物上的价值以及它在改进工业发酵效率上的潜在作用.

英文摘要：

A strain of Exiguobacterium aurantiacum ATCC49676 was found to be of great potential to produce lactic acid （LA）. In order to screen the metabolites that might regulate or affect the acid yield, a relative higher LA production condition was defined through full factorial experiment design. Fresh cultures harvested from the basic and the higher LA production conditions were subjected to metabolic fingerprint analysis by gas chromatography-mass spectrometry. Significance analysis indicated a distinct change of an intercellular metabolite-L-glutamic acid （Glu）. When ATCC49676 was treated by Glu, LA yield declined with the increasing added Glu concentrations. Relative enzyme quantification confirmed that Glu decreased the intracellular lactate dehydrogenase content. This study proved the merit of metabolic fingerprint analysis in exploring the phenotype specific intracellular metabolite and its potential roles in improving industrial fermentation efficiencies.