Air-Drying of Cells, the Novel Conditions for Stimulated Synthesis of Triacylglycerol in a Green Alga, Chlorella kessleri

Details

• Alternative Title:
  PLoS One
• Personal Author:
  Shiratake, Takuma ; Sato, Atsushi ; Minoda, Ayumi ; Tsuzuki, Mikio ; Sato, Norihiro
• Description:
  Triacylglycerol is used for the production of commodities including food oils and biodiesel fuel. Microalgae can accumulate triacylglycerol under adverse environmental conditions such as nitrogen-starvation. This study explored the possibility of air-drying of green algal cells as a novel and simple protocol for enhancement of their triacylglycerol content. Chlorella kessleri cells were fixed on the surface of a glass fibre filter and then subjected to air-drying with light illumination. The dry cell weight, on a filter, increased by 2.7-fold in 96 h, the corresponding chlorophyll content ranging from 1.0 to 1.3-fold the initial one. Concomitantly, the triacylglycerol content remarkably increased to 70.3 mole% of fatty acids and 15.9% (w/w), relative to total fatty acids and dry cell weight, respectively, like in cells starved of nitrogen. Reduction of the stress of air-drying by placing the glass filter on a filter paper soaked in H2O lowered the fatty acid content of triacylglycerol to 26.4 mole% as to total fatty acids. Moreover, replacement of the H2O with culture medium further decreased the fatty acid content of triacylglycerol to 12.2 mole%. It thus seemed that severe dehydration is required for full induction of triacylglycerol synthesis, and that nutritional depletion as well as dehydration are crucial environmental factors. Meanwhile, air-drying of Chlamydomonas reinhardtii cells increased the triacylglycerol content to only 37.9 mole% of fatty acids and 4.8% (w/w), relative to total fatty acids and dry cell weight, respectively, and a marked decrease in the chlorophyll content, on a filter, of 33%. Air-drying thus has an impact on triacylglycerol synthesis in C. reinhardtii also, however, the effect is considerably limited, owing probably to instability of the photosynthetic machinery. This air-drying protocol could be useful for the development of a system for industrial production of triacylglycerol with appropriate selection of the algal species.
• Subjects:
  Chlorella Chlorophyll Triglycerides
• Source:
  PLoS One. 2013; 8(11).
• Document Type:
  Journal Article
• Volume:
  8
• Issue:
  11
• Collection(s):
  CDC Public Access
• Main Document Checksum:
  urn:sha256:f55b5e09b152a1f36e2bf31299945f656a50ae1c74af292e01010dcaf81e8545
• Download URL:
  https://stacks.cdc.gov/view/cdc/21349/cdc_21349_DS1.pdf
• File Type:
  [PDF - 867.70 KB ]