“Investigation On the Utilization of Horse Manure Extract as an Additive in the Growth Of Spirulina Sp”

Abstract

This study attempts to evaluate the feasibility of using horse manure as a cost-effective alternative nutrient source for microalgae cultivation. By harnessing its abundant minerals and cost-effectiveness, this study seeks to reduce expenses associated with nutrient mediums, ultimately enhancing the economic appeal of microalgae-derived products for commercial use. The horse manure obtained from the stables was sun-dried and then ground into a powder using a mixer grinder. To obtain horse manure extract, 10 g of powdered manure is mixed with 200 ml of water and boiled in a water bath for 30 minutes. In the cultivation process of Spirulina sp, horse manure extract supplements were introduced at different concentrations (0.2ml, 1ml, 2ml, 3ml, 4ml) into the indoor modified growth medium. A control group was included, utilizing an indoor modified growth medium without any addition of horse manure extract supplement. The research focused on exploring the effects of various concentrations of horse manure extract on indoor Spirulina cultivation, showing encouraging results. Using a 4ml/200ml concentration of horse manure extract led to Spirulina exhibiting a dry weight of 0.098±0.0015 g, a specific growth rate of 0.0051±0.00009, and a density of 0.0138±0.00003. Moreover, when subjected to a concentration of 0.2 ml/200 ml, Spirulina demonstrated 5.322±0.011 µg/l of carotenoids. Chlorophyll a, b, and c were detected in Spirulina across a range of horse manure extract concentrations, namely 1ml/200ml (9.770±0.018 mg/L), 3ml/200ml (3.176±0.010 mg/L), and (0.805±0.031 mg/L). These levels of chlorophyll were notably higher compared to the control medium in indoor culture settings.