Algal growth control by a barley straw extract.
In recent years, there has been an apparent increase in the occurrence of harmful algal blooms occurring in potable waters. The potential of a simple barley straw extract to inhibit algal growth was assessed. Algal growth in lakewater was inhibited by the addition of barley straw (1% w/v), with the chlorophyll a concentration remaining below the original level (40 micrograms l-1) throughout the experiment. In contrast, in the presence of wheat straw, algal biomass increased, reaching a final chlorophyll a concentration of 1160 micrograms l-1 after 28 days. Analysis of the remaining particulate straw at the end of the experiment showed that the lignin content of barley straw had increased significantly from 10-33% (w/w). Further, a preparation of a simple aqueous extract from the decomposed-barley straw was found to inhibit the cyanobacteria Microcystis sp. and the algal species Scenedesmus, with chlorophyll a levels some 10-fold lower than in untreated flasks. This study shows that a decomposed-barley extract, even in a very dilute concentration (0.005%) was capable of inhibiting the growth of Microcystis sp., a commonly occurring cyanobacterium which produces the toxin microcystin and has been responsible for some of the most serious pernicious algal blooms in the UK.
Ball
A S
AS
Department of Biological Sciences, John Tabor Laboratories, University of Essex, Wivenhoe Park, Colchester, Essex CO4 3SQ, UK. andrew@essex.ac.uk
Williams
M
M
Vincent
D
D
Robinson
J
J
D002734:Chlorophyll / Q000032:analysis*; D000077194:Chlorophyll A; D000460:Chlorophyta / Q000254:growth & development / Q000378:metabolism*; D000458:Cyanobacteria / Q000254:growth & development / Q000378:metabolism*; D001467:Hordeum / Q000737:chemistry*; D008031:Lignin / Q000032:analysis; D014908:Triticum / Q000737:chemistry
D002734:Chlorophyll; D008031:Lignin; D000077194:Chlorophyll A