Host seaweed extracts effect on epiphytic Acrochaetium sp growth and its phycobilipigments content and biological activity

The association of microscopic epiphytic algae with marine macroalgae (seaweeds) hosts is common. One such epiphyte is Acrochaetium species and its growth under the influence of its host nutrients and bioprospecting is not investigated. In this work, the nutritional influence of host seaweed extracts red Gracilaria corticata, green Ulva fasciata, and brown Sargassum wightii, on the growth of Acrochaetium sp. CUKPSAK006 along with its phycobilipigments (PBPs) content and its biological activities was studied. The optimized laboratory conditions for the growth of Acrochaetium sp. found pH 7.6 and salinity 20‰ in MP1 medium. High growth is obtained in an MP1 medium supplemented with extracts of G. corticata and S. wightii but is insignificant compared to the control suggesting a facultative nutritional preference. However, PBPs possessing high anti-oxidant properties was found in the Acrochaetium sp. grown in the extracts of G. corticata and U. fasciata whereas significantly high hyaluronidase-inhibitory activity was observed in PBPs of Acrochaetium grown in the G. corticata extract. This study concludes that epiphytic microscopic Acrochaetium is a potential cultivable species for phycobilin pigment production either by defined medium or using seaweed extract supplement, considering the food and cosmetic values because of its good biological properties (anti-oxidant and anti-hyaluronidase).