ABSRACT
The growth response and sensitivity of Chlorella vulgaris and Coelastrum nagelli to the antibiotic, amoxicillin was systematically studied. The microalgae species were grown in modified Chu medium and set up for fourteen (14) days. The concentrations, 0% (control), 10%, 20%, 30%, 40%, 50% and 100% were used and the microalgal growth response was determined using a visible spectrophotometer at an absorbance of 750nm. Physicochemical parameters such as pH, conductivity and TDS were also analysed using their respective standard methods. Descriptive statistics such as Mean and standard error were calculated using Microsoft Excel 2010. The result revealed that amoxicillin stimulated growth at all concentrations of both microalgae. Chlorella vulgaris showed highest growth rate in 40% concentration followed by 100%, 50%, 30%, 10%, 20% and control respectively. For Coelastrum nagelli, 100% had the highest growth followed by 40%, 50%, 0%, 30%, 20% and 10%. Chlorella vulgaris and Coelastrum nagelli had their maximum percentage yield at 100% concentration on day 8 and 14 respectively. The lowest percentage yield of both microalgae was recorded at 0%. At 100% concentration, Chlorella vulgaris had the highest cumulative growth closely followed by 40% and 50%, while the lowest cumulative growth was recorded at 0% concentration. The highest cumulative growth of Coelastrum nagelli was 40% closely followed by 100% and 50%, while the lowest cumulative growth was at 20%. The results of chemical parameters such as conductivity and TDS decreased with increasing concentrations of amoxicillin. However, pH changed across the different concentrations in an irregular pattern. This study shows that the growing Chlorella vulgaris and Coelastrum nagelli have the potentials to bioremediate amoxicillin and possibly other antibiotics.
