Schmidt André D, Heinekamp Thorsten, Matuschek Markus, Liebmann Burghard, Bollschweiler Claus, Brakhage Axel A
Department of Molecular and Applied Microbiology, Leibniz-Institute for Natural Products Research and Infection Biology, Hans-Knoell-Institute, Jena, Germany.
Appl Microbiol Biotechnol. 2005 Jun;67(4):549-55. doi: 10.1007/s00253-005-1941-2. Epub 2005 Mar 3.
The zygomycete fungus Blakeslea trispora is used commercially as natural source of beta-carotene. beta-Carotene production is strongly induced during mating of two strains of the opposite sex and results in the production of the pheromone trisporic acid, which in turn stimulates enhanced beta-carotene biosynthesis. beta-Carotene production is due to the enzymatic activity of phytoene synthase, lycopene cyclase and phytoene dehydrogenase. The corresponding genes, carRA and carB, were isolated from a cosmid library generated from B. trispora strain ATCC14272. The steady state level of carB and carRA mRNA transcripts under different mating conditions was monitored by both northern blot analysis and quantitative real-time PCR. The steady state levels of carRA and carB mRNA of non-mated and mated B. trispora were quantified relative to transcript levels of the translation elongation factor 1alpha-encoding tef1 gene, since tef1 is transcribed independently of mating. Transcription levels of both carB and carRA were strongly induced only under mating conditions. These data suggest that beta-carotene production in B. trispora is due to increased transcription of the biosynthesis genes carB and carRA.
接合菌纲真菌三孢布拉氏霉被作为β-胡萝卜素的天然来源进行商业利用。在两个异性菌株交配过程中，β-胡萝卜素的产生被强烈诱导，并导致信息素三孢酸的产生，而三孢酸又反过来刺激β-胡萝卜素生物合成的增强。β-胡萝卜素的产生归因于八氢番茄红素合成酶、番茄红素环化酶和八氢番茄红素脱氢酶的酶活性。相应的基因carRA和carB是从由三孢布拉氏霉ATCC14272菌株构建的黏粒文库中分离得到的。通过Northern印迹分析和定量实时PCR监测了不同交配条件下carB和carRA mRNA转录本的稳态水平。相对于编码翻译延伸因子1α的tef1基因的转录本水平，对未交配和已交配的三孢布拉氏霉的carRA和carB mRNA的稳态水平进行了定量，因为tef1的转录独立于交配过程。只有在交配条件下，carB和carRA的转录水平才会被强烈诱导。这些数据表明，三孢布拉氏霉中β-胡萝卜素的产生是由于生物合成基因carB和carRA转录的增加。
