Sporulation and sterilization method for axenic culture of Gelidium canariensis

Abstract

A sporulation and sterilization procedure was used to establish axenic cultures of sporelings of Gelidium canariensis. Sporangial branchlets excised from the thallus were rinsed in distilled water twice and in 1% sodium hypochlorite (2 min). The branchlets were cultivated overnight in multiwell plates with 0.3 mi of autoclaved seawater to promote spore liberation in 90% of the cultivated branchlets. The branchlets were transferred to an antibiotic solution made of ampicillin, penicillin, rifampicin, nystatin (0.2 mg ml(-1) each) and 0.1 g ml(-1) of GeO2 in liquid PES for 45 days, during which clusters of spores (85-100 spores) were observed on the surface of the branchlet. After 55 days, they became axenic sporelings with the prostrate and erect system characteristic of Gelidium canariensis.