Influence of temperature and methyl jasmonate on Scenedesmus incrassulatus

The effect of the methyl ester of jasmonic acid (MeJA) in 10 muM concentration was studied on the development of the bacterial contaminants and on the content of some metabolites in Scenedesmus incrassulatus cultivated at temperatures 15, 20, 25, 30, and 36 degreesC. The number of bacteria on algae cells increased with the rise in temperature. Application of MeJA into nutrient medium inhibited the development of bacterial pathogens more than 3 times at 20 degreesC, 2.3 times at 30 degreesC, and 2.6 times at 36 degreesC without changing the species composition. MeJA caused an increase of the protein content in algae cells. The contents of palmitic and linoleic acids increased with the rise of temperature from 15 to 36 degreesC. At the same time the contents of linolenic and oleic acid decreased. At low temperatures, cultivation with MeJA induced more significant changes in the composition of C18 acids while at high temperature the changes were more pronounced in C16 acids. Treatment with MeJA decreased the activity of glutamate dehydrogenase at optimal and suboptimal temperatures and increased it at superoptimal temperature. Hence MeJA jasmonate had a positive effect on the tolerance of S. incrassulatus to stress temperatures, which was also demonstrated by better growth.