Thiocyanate degradation by Acremonium strictum and inhibition by secondary toxicants

Abstract

Acremonium strictum, capable of degrading 7.4 g thiocyanate l(-1), was isolated from wastewater condensate from coke-oven gas. Ammonia and sulfate were the final products from thiocyanate degradation with a stoichiometric ratio of near 1:1. The highest degradation activity was at pH 6. Although the degradation rate started to be inhibited above 4 g thiocyanate l(-1), thiocyanate was completely degraded up to 7.4 g l(-1) within 85 h in shake-flask cultures. The degradation of thiocyanate was inhibited by phenol above 625 mg l(-1), by cyanide above 16 mg l(-1), and by nitrite above 100 mg l(-1). However, ammonia and nitrate had negligible inhibition on thiocyanate degradation up to 3 g l(-1) and 1.5 g l(-1), respectively.