Short note on the effects of ethanolic extracts of selected South African seaweeds on the growth of commercially important plant pathogens, Rhizoctonia solani Kühn and Verticillium sp.

This paper describes the biological activity of ethanolic extracts from some commonly abundant seaweeds from KwaZulu-Natal, South Africa. The pour-plate method was used to determine the effects of selected seaweed extracts on the growth of two phytopathogens; Verticillium sp. and Rhizoctonia solani. Extracts from Caulerpa filiformis and Ulva rigida (Chlorophyta); Zonaria tournefortii (Phaeophyta); and Hypnea spicifera, Gelidium abottiorum and Osmundaria serrata (Rhodophyta) inhibited fungal growth by more than 50%. The extracts from the rhodophytes, Spyridia cupressina and Beckerella pinnatifida showed the weakest antifungal activity of the seaweeds tested. The pour plate method demonstrated both fungal growth promotion and inhibition, due to the seaweed extracts. At low concentrations (1:16 and 1:32 dilutions) the H spicifera extract promoted the growth of R. solani

Metal concentrations in seaweeds from KwaZulu-Natal, South Africa - a first report

A survey of concentrations of selected metals in some common seaweeds from the KwaZulu-Natal coast was conducted. Samples of 40 seaweeds were collected from Palm Beach, Isipingo Beach and Mission Rocks and analysed for metals by X-ray fluorescence. High metal concentrations were found in a number of the seaweeds examined, Stypocaulon funiculare (Phaeophyta) and Osmundaria serrata (Rhodophyta) showed high levels of a wide range of metals and are recommended for further study as indicator species for metals in the marine environment of the KwaZulu-Natal coast

Saved by seaweeds (II): Traditional knowledge, home remedies, medicine, surgery, and pharmacopoeia

Humankind has known the benefits of seaweeds since time immemorial. A number of these applications were likely passed down in the oral histories particularly of coastal dwellers and those using different seaweeds as food and treatments for common ailments. The beneficial use of many types of seaweeds was reported and recorded into some of the first written medical texts. The common benefits of these seaweed concoctions and applications seems to be linked to the presence of hydrocolloids and the various bioactive compounds. We believe this collation brings together, for the first time to our knowledge, a number of excerpts from major medical publications and esteemed writers of the day. It provides a rich background supporting the positive applications of various seaweeds to a multitude of human ailments, from skin to bowel, inside and out and many of the places in between!The work by OGM is supported by the Carlsberg Foundation. The authors would like to thank two anonymous reviewers for their constructive comments which assisted in the improvement of this article