Influence of mussel Mytilus galloprovincialis exometabolites on R-phycoerythrin concentration in red alga Gelidium spinosum when grown in polyculture

To increase R-phycoerythrin concentration in red Black Sea alga Gelidium spinosum (S. G. Gmelin) P. C. Silva, 1996 (Rhodophyta), it was cultivated in laboratory conditions in polyculture microalga Tetraselmis viridis – mussel Mytilus galloprovincialis – Gelidium; the results of the study are presented. The positive effect of mussel exometabolites on R-phycoerythrin concentration in Gelidium in polyculture is described. The relevance of the work is determined by the value of R-phycoerythrin, which is used as a powerful antioxidant, as well as a marker in cytometry and microscopy. The aim of the study is to increase R-phycoerythrin concentration in Gelidium using the polyculture method. As a material, Gelidium from the fouling of rocks and coastal protection structures of Karantinnaya Bay (Sevastopol) was used; it was cultivated in a laboratory installation with eight working volumes, four of which contained mussels. Mussel decontamination, supplemented with mineral salts and biogens, was used as a nutrient medium for Gelidium. The combination of mussel exometabolites with previously developed nutrient medium, based on Black Sea water and enriched with nutrients and mineral salts, results in an increase in R-phycoerythrin concentration by more than 2 times, while the addition of exometabolites to pure filtered seawater increases it maximum by 35 %. Approximate ratios of polyculture elements in 1.5-L volumes, allowing to achieve the desired results in 2 weeks, are as follows: 2 g of Gelidium / 50–60 g of two-year-old mussels / 0.4–0.6 g of microalga wet weight.