摘要
类胡萝卜素是一种应用广泛的脂溶性天然色素和抗氧化剂。本文以一株典型的紫色非硫光合细菌——沼泽红假单胞菌(Rhodopseudomonas palustris)为实验对象,研究了光照厌氧体系下有机酸碳源种类、盐浓度和光照强度等培养条件对其生长和产类胡萝卜素量及组成的影响,并探究了类胡萝卜素的抗氧化性。研究结果表明:在实验的8种有机酸中,以乳酸为碳源可获得最高生物量以及类胡萝卜素含量;产类胡萝卜素最适光照强度(500lx)低于该菌生长所需(2000lx);高盐浓度(7.5g/L)可促进该菌合成类胡萝卜素,是其生长所需最佳盐浓度的三倍。在优化后的培养条件下,该沼泽红假单胞菌类胡萝卜素含量可达15.35mg/L。所产类胡萝卜素由6种组成,培养条件对其组成有明显影响,高盐浓度和强光照会促进3,4-脱氢玫红品(3,4-didehydrorhodopin)的合成,可能是光合细菌应对环境压力的一种机制。抗氧化性分析和数据拟合表明不同组成的类胡萝卜素抗氧化能力差异显著,经基螺菌黄素和3,4-脱氢玫红品的抗氧化能力最强。
Carotenoids are widely used as fat-soluble natural pigments and antioxidants.Here we chose Rhodopseudomonas palustris,a typical purple nonsulfur photosynthetic bacteria,to produce carotenoids under photo-anaerobic conditions.The effects of culture conditions such as organic acid types,salt concentration and light intensity on the cell growth,carotenoid content and composition were studied,and the antioxidant activities of carotenoids were also explored.The results showed that lactic acid as carbon source produced the highest biomass and carotenoid content among the eight organic acids tested.The optimum light intensity(500lx)for carotenoid content was lower than that required for the growth of Rhodopseudomonas palustris(2000lx).High salt concentration promoted the synthesis of carotenoids,and the optimum concentration(7.5g/L)was three times that required for its growth.Under optimized conditions,the carotenoid content reached 15.35mg/L.Six kinds of carotenoids were detected,and the composition was greatly affected by the culture conditions.High salt concentration and strong light favored the synthesis of 3,4-didehydrorhodopin,which might be a mechanism for photosynthetic bacteria to adapt to environmental stress.The antioxidant activity test and data analysis showed that antioxidant activities of the produced carotenoids highly depended on their composition,and OH-spirilloxanthin and 3,4-didehydrorhodopin showed strong antioxidant activities.
作者
李南楠
彭思雨
闫海
尹春华
LI Nannan;PENG Siyu;YAN Hai;YIN Chunhua(School of Chemistry and Biological Engineering,University of Science and Technology Beijing,Beijing 100083,China)
出处
《化工进展》
EI
CAS
CSCD
北大核心
2023年第11期5891-5899,共9页
Chemical Industry and Engineering Progress
基金
国家重点研发计划(2019YFC1906302,2019YFC1906301)
国家自然科学基金(11971055)。
关键词
光合细菌
类胡萝卜素
抗氧化活性
有机酸
photosynthetic bacteria
carotenoid
antioxidant activity
organic acids
