Variation in Phospholipid Ester-Linked Fatty Acids and Carotenoids of Desiccated Nostoc commune (Cyanobacteria) from Different Geographic Locations

摘要

Profiles of phospholipid fatty acids and carotenoids in desiccated Nostoc commune (cyanobacteria) collected from China, Federal Republic of Germany, and Antarctica and in axenic cultures of the desiccation-tolerant strains N. commune UTEX 584 and Hydrocoleum strain GOEI were analyzed. The phospholipid fatty acid contents of the three samples of desiccated Nostoc species were all similar, and the dominant compounds were 16:1ω7c, 16:0, 18:2ω6, 18:3ω3, and 18:1ω7c. In comparison with the field materials, N. commune UTEX 584 had a much higher ratio of 18:2ω6 to 18:3ω3 (5.36) and a significantly lower ratio of 18:1ω7c to 18:1ω9c (1.86). Compound 18:3 was present in large amounts in the samples of desiccated Nostoc species which had been subject, in situ, to repeated cycles of drying and rewetting, but represented only a small fraction of the total fatty acids of the strains grown in liquid culture. This finding is in contrast to the data obtained from studies on the effects of drought and water stress on higher plants. Field materials of Nostoc species contained, in contrast to the axenic strains, significant amounts of apocarotenoids and a P384 pigment which, upon reduction with NaBH4, yielded a mixture of a chlorophyll derivative and a compound with an absorption maximum of 451 nm. A clear distinction can be made between the carotenoid contents of the axenic cultures and the desiccated field materials. In the former, β-carotene and echinenone predominate; in the latter, canthaxanthin and the β-γ series of carotenoids are found.