Effect of herbicides on chlorophyll-a, ?- caroten, phycocyanin and allophycocyanin content of Anabaena sp.

Abstract

Pigments are frequently use in medicine, food, pharmacology, cosmetic, ink and textile preparations. Cyanobacteria have a great potential for use as pigment producer, because they are easy to grow with simple nutrient requirements, unlike other microbial systems and additionally have a large number of pigment. Cyanobacteria produce some pigments such as chlorophyll-a, carotenoids, phycobiliproteins. In addition, cyanobacteria can fix free atmospheric nitrogen. Environmental conditions affect the cyanobacterial growth and pigment production. Herbicides use commonly in paddy fields. Because of this, herbicides can affect to non-target microorganisms such as cyanobacteria. In this study, production of some pigments by Anabaena sp. GO10 were studied using different herbicides in BG-11 medium. As herbicide, fenoxaprop-p-ethyl and cyhalofop-0butyl used in this study. In this work, different herbicide concentrations were applied on pigment production. Initial fenoxaprop-p-ethyl concentrations (6,25 mg/L) stimulated chlorophyll-a, ?- caroten, phycocyanin and allophycocyanin contents. But increasing herbicide concentrations suppressed to the all of pigment contents. The all of pigment contents of Anabaena sp. GO10 completely suppressed by 100 mg/L fenoxaprop-p-ethyl concentration. The other herbicide is cyhalofop-butyl. Initial cyhalofop-butyl concentrations partly stimulated the pigment contents. But, the pigment contents of Anabaena sp. GO10 increased sharply by 25 mg/L cyhalofop-butyl concentrations. The all of pigment contents of Anabaena sp. GO10 completely repressed by 400 mg/L cyhalofop-butyl concentrations.