Abstract
The unicellular aerial microalga, Elliptochloris reniformis (Chlorophyceae), was isolated from the bark of trees growing on the campus of Kogakuin University in Hachioji, Tokyo, and cultured on the protein ex-tract of jellyfish (Aurelia aurita) caught in Tokyo Bay. Liquid chromatography analysis revealed that the major protein components in the extract were mucin and collagen. Culture of the microalga in a liquid medium containing the jellyfish protein extract for 13 days under light conditions resulted in a six-fold increase in microalgal biomass and a marked decrease in the concentration of the jellyfish proteins in the medium; however, no algal growth was observed in cells cultured in the dark. These findings suggested that the alga used the proteins as a nitrogen source for growth under light conditions. In addition, E. reniformis could be cultured in the presence of protein extract from jellyfish for 49 days under wet or dry conditions on external walls (e.g., mortar). These findings are useful for cultivating microalgae on wall surfaces using a jellyfish protein extract as a growth medium.
