Aims: Applying competitive exclusion micro-organisms to control hydrogen sulfide (H(2)S) gas produced by hydrogen sulfide-producing bacteria (SPB) in chicken meat. Methods and Results: Five SPB strains, isolated from animal by-products, were used for screening lactic acid bacteria (LAB) that can inhibit the production of H(2)S by SPB in trypticase soy broth supplemented with l-cysteine (TSB-L-cys). A sensitive and accurate test strip method was developed for H(2)S determination in real time. One LAB strain, isolate L86, from cheese whey, demonstrated the highest inhibitory activity against the production of H(2)S by SPB. The isolate L86 was confirmed as Enterococcus faecium that does not possess genes encoding for vancomycin resistance based on PCR analysis. Enterococcus faecium strain L86 reduced (P < 0.05) the yield of H(2)S upto 51.2% in 10 h at 35 degrees C in TSB-L-cys medium. In fresh chicken meat, the yield of H(2)S produced by the artificially inoculated SPB was reduced (P < 0.05) by 48.6, 49.7 and 69.8% in 10 h at 35, 30 and 25 degrees C, respectively. Enterococcus faecium strain L86 also reduced (P < 0.05) by 53.8% on the yield of H(2)S produced by the indigenous SPB in partially spoiled chicken meat at 35 degrees C for 10 h. Conclusions: Enterococcus faecium strain L86 is effective on inhibiting the production of H(2)S by SPB. Significance and Impact of the Study: The application of this biological agent to raw animal by-products will provide a safer working environment in rendering processing plants and produce higher-quality rendered products.