In the present study, the chronic and harmful effects of different doses of a triazole fungicide-Tebuconazole on the growth, metabolic and enzymatic variations in the filamentous paddy field cyanobacterium, Westiellopsis prolifica Janet was explored. The growth of the cyanobacterium was determined by estimating the change in its pigment contents-Chlorophyll-a, carotenoids and accessory pigments- Phycocyanin, Allophycocyanin and Phycoerythrin, showing a consistent decline in the pigment percentage reduction by 92%, 93%, 83%, 95% and 100% respectively with increasing doses of the fungicide by the end of sixteen days. The metabolic and enzymatic activities were also adversely affected. Although Carbohydrates, proteins and amino acids reduced by 96%, 92% and 90% respectively, after 16 days when treated with 60ppm of the fungicide, a gradual rise in the total phenol content was recorded. Moreover, percentage reduction in the enzymes Nitrate Reductase (NR), Glutamine Synthetase (GS) and Succinate Dehydrogenase (SDH) was also registered by 93%, 90% and 98% respectively with triazole fungicide.
chronic toxicity, enzymes, metabolites, pigments, tebuconazole, Westiellopsis prolifica Janet