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.

Diatoms recovery from wastewater: Overview from an ecological and economic perspective

“…In this, a planktonic net of a specific size is used, which does not allow any other organism to pass through except the target species. In gravity separation, diatoms settle down as sediments while leaving other microalgae in the suspension, which can be discarded further [ 66 ].…”

Decontamination treatments to eliminate problem biota from macroalgal tank cultures of Osmundea pinnatifida, Palmaria palmata and Ulva lactuca

“…Druehl and Hsiao 1969; Yan 1984; Aguirre-Lipperheide and Evans 1993). These aggressive treatments can severely impact the physiology of macroalgae as they do not possess a protective cuticle, and so are highly susceptible to chemical damage (Fries 1980; Baweja et al 2009; Fernandes et al 2011). However, since the objective of such studies has been the isolation of axenic tissue, this physiological impact is acceptable, as long as the macroalga recovers successfully, allowing continued cultivation.…”

“…1 %, for up to 30 min (Druehl and Hsiao 1969; Lee 1985), although 5 % or saturated solutions have been used for up to 5 min (Hsiao and Druehl 1971; Fries 1977). Despite its common usage, it oxidant activity can easily damage tissues leading to softening and/or pigment loss (Baweja et al 2009; Fernandes et al 2011). This study has shown that the damage takes some time to repair, with little recovery seen a wk afterward (Figs.…”

Growth responses of Chondrus ocellatus Holmes (Gigartinales, Rhodophyta) to two endophytes, Mikrosyphar zosterae Kuckuck (Ectocarpales, Ochrophyta) and Ulvella ramosa (N. L. Gardner) R. Nielsen (Ulvales, Chlorophyta) in culture

“…Light was provided by 40 W cool-white fluorescent tubes and the level of irradiance was measured using a digital illumination meter (DX-200; INS Enterprise Co., Taipei, Taiwan). The growth of diatoms was inhibited by adding GeO 2 (3 μg L -1 ) in culture medium during the first week of cultivation to reduce any negative effects of GeO 2 (Fernandes et al 2011). Filamentous brown M. zosterae and green U. ramosa endophytes appeared on the surface of frond discs within 3 to 4 weeks of cultivation.…”