Protocol for seaweed decontamination to isolate unialgal cultures

ABSTRACT

Decontamination protocols in seaweeds are essential tools for ecophysiological studies in laboratory cultures. These protocols consist of a set of procedures and physical and chemical treatments that must be adjusted for each species. Thus, the effects of explant size and of combinations of physical treatments (brushing and cutting) and chemical treatments (sodium hypochlorite, detergent, seawater, distilled water, germanium dioxide) on the process of obtaining unialgal culture of two pigmentar morphos of Hypnea musciformis were investigated. It was found that thallus segments 50 mm in length, when transported from the field to the laboratory, remained healthier and were less susceptible to epiphytes than those 7 mm in length. The collected material had surfaces contaminated by diatoms, which were weakly attached, as well as surface contamination caused by strongly attached Sahlingia subintegra. The most efficient combination of physical and chemical treatments was explant brushing, cutting and washing with detergent. This combination eliminated the contamination by S. subintegra, but not all of the diatom contamination. The population of the latter was reduced by using physical treatment and by washing with detergent and distilled water and then exterminated by using germanium dioxide (0.003 mg/L). Employing this protocol, unialgal cultures of H. musciformis could be established in approximately eight to ten weeks.