Ac. Chamier et E. Tipping, EFFECTS OF ALUMINUM IN ACID STREAMS ON GROWTH AND SPORULATION OF AQUATIC HYPHOMYCETES, Environmental pollution, 96(3), 1997, pp. 289-298
We investigated, by field and laboratory experiments, the effects of a
luminium lit an acid sti earn (pH 5.0) on the growth and sporulation o
f aquatic hyphomycete fungi which degrade organic litter. The stream w
ater had monomeric aluminium (Al-m) concentrations of 9.1-13.4 mu M -
fifty times higher than a nearby circumneutral stream. Alder leaves su
bmersed in the stream accumulated Al, most of which was tightly bound.
Growth rates of four species of aquatic hyphomycetes were altered by
inclusion of Al-m in the culture medium. On a polypectate substrate, a
nd on low-phosphate medium with glucose, growth rates increased signif
icantly. On a low-nutrient substrate of homogenized alder leaves, grow
th rates were inhibited by aluminium. The pattern of mycelial growth w
as found to be different on a polypectate medium including Al-m, compa
red with a control without aluminium. There was a significant increase
in hyphal radial growth and a decrease in the hyphal growth unit. The
effect resembled the growth of a starved fungal colony. Treatment wit
h Al-m, decreased pectinase production It the four fungal species test
ed. The capacity of these species to sporulate Mas reduced by flooding
culture plates with Al-m solution. These deleterious metabolic effect
s were most severe in isolates taken from circumneutral streams and le
ss marked, though significant, in species originating from acid stream
s. (C) 1997 Elsevier Science Ltd.