A developmental stage of hyphal cells shows riboflavin overproduction instead of sporulation in Ashbya gossypii

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• 作者：Susanne Nieland (1)
  K.-Peter Stahmann (1)
  
• 关键词：Protoplast ; FACS ; Riboflavin ; Ashbya gossypii
• 刊名：Applied Microbiology and Biotechnology
• 出版年：2013
• 出版时间：December 2013
• 年：2013
• 卷：97
• 期：23
• 页码：10143-10153
• 全文大小：
• 作者单位：Susanne Nieland (1)
  K.-Peter Stahmann (1)
  
  1. Fakultt f Naturwissenschaften, Brandenburgische Technische Universitt Cottbus-Senftenberg, Groenhainer Str. 57, 01968, Senftenberg, Germany
  
• ISSN：1432-0614

文摘

The hemiascomycete Ashbya gossypii develops a mycelium. Nutritional stress leads to its differentiation into sporangia. These generate spores. In parallel, the yellow pigment riboflavin is produced. Intracellularly accumulated riboflavin, made visible as a bright green fluorescence, was observed in only 60% of the hyphal cells. For the remaining 40%, it was unclear whether these cells simply export riboflavin or its biosynthesis remains down-regulated in contrast to the accumulating cells. The approach followed in this work was to convert the hyphae into protoplasts by enzymatic degradation of the cell wall. Afterwards, the protoplasts were sorted by fluorescence-activated cell sorting on the basis of riboflavin accumulation. When a reporter strain expressing lacZ under the control of the most important riboflavin biosynthesis promoter, RIB3, was used, green protoplasts were found to have more than tenfold greater reporter activity than hyaline protoplasts. This was true on the basis of total protein as well as on the basis of hexokinase specific activity, a marker for constitutive expression. These results allow the conclusion that hyphal cells of A. gossypii differ in phenotype regarding riboflavin overproduction and accumulation.