Influence of polyamines on growth and metabolism of Dunaliella primolecta

Addition of natural polyamines (putrescine, spermidine or spermine) to the culture medium stimulates growth of Dunaliella primolecta and results in an increased photosynthesis ( + 200%), chi a content ( + 300%) and ATP content (+182%). The results are compared with those induced by synthetic polyamines, such as N,N'-bis (3-aminopropyl) diaminoethane (BAPDE) or l,4,8,ll,tetraazacyclotetradecane (CYCLAM). BAPDE and CYCLAM increase photosynthesis, ATP level and chi a content to the same extent, but have a negative effect on the growth of the alga. The synthetic polyamines increase oxygen uptake, whereas the natural polyamines have no effect. These results are discussed in relation to the hypothesis of polyamines acting as growth regulators or as nitrogen source for the alga.