Development of Odorous Gases Reduction Agents Using Recombinant Yeast-Derived Extract

Objective: To investigate the effects of two yeast-derived extracts on the reduction of NH3, H2S and CH3SH, and to confirm the availability as environmental improvement agents. Methods: First, the experiment was conducted on a lab-scale, treated with 1%, 2%, 5% and 10% extracts in manure, followed by reaction for 3 days. The concentrations of NH3, H2S and CH3SH were measured using a gas detector. A scale-up odor reduction experiment was then conducted in a swine house. Finally, the odor reduction effect was compared with the commercial product (M-product) for evaluation. Results: As a result of comparing the ammonia gas reduction with respect to the concentration of the yeast-derived extract, it was confirmed that the reduction of ammonia was improved depending on the treated concentration in both samples of Yeast-W and Yeast-SS. The concentration of NH3, H2S, and CH3SH from swine house showed significant differences between that of manure from the control and extract treatment group, with Yeast-SS showing the highest efficacy. The reduction rate of Yeast-SS 1% treatment on NH3 was 46.7%, which appeared similar to that of 2% treatment of M-product. Also, the reduction rate of Yeast 2% treatment reached a maximum of 53.4%, which showed a high efficiency for the reduction of NH3. Conclusion: Yeast-SS is an effective odor removal agent even at low concentrations compared with other odor reducing agents, with potential applicability as an environmental improvement agent for managing odorous gas of swine manure.