The survival of multidrug‐resistant bacteria in thermophilic and mesophilic anaerobic co‐digestion of dairy manure and waste milk
2013
Beneragama, Nilmini | Iwasaki, Masahiro | Lateef, Suraju A. | Yamashiro, Takaki | Ihara, Ikko | Umetsu, Kazutaka
Anaerobic digestion is considered as a promising method to manage animal waste with antibiotic‐resistant bacteria. Current research was conducted to investigate the survival of multidrug‐resistant bacteria (MDRB) resistant to three groups of antibiotics: (i) cefazolin, neomycin, vancomycin, kanamycin (group 1); (ii) penicillin, oxytetracycline, ampicillin, streptomycin (group 2); and (iii) cefazolin, neomycin, vancomycin, kanamycin, penicillin, oxytetracycline, ampicillin, streptomycin (group 3), in anaerobic digestion of dairy manure and co‐digestion of dairy manure and waste milk at 37°C and 55°C for 22 days, respectively. The population densities of three groups of MDRB on peptone, tryptone, yeast and glucose agar plates incubated at 30°C for 7 days before and after digestion showed 100% destruction in both digestates at thermophilic temperature. Overall reduction of more than 90% of three groups of MDRB was observed in mesophilic digestion with no significant differences (P > 0.05) between manure and milk mixture. Co‐digestion of dairy manure and waste milk always produced significantly (P < 0.05) higher total gas and methane gas than digestion of manure alone at both temperatures. Gas production in each case was significantly (P < 0.05) higher in thermophilic digestion than in mesophilic digestion. The results demonstrate that thermophilic co‐digestion of dairy manure and waste milk offers more benefits in terms of the environment and economy.
Afficher plus [+] Moins [-]Mots clés AGROVOC
Informations bibliographiques
Cette notice bibliographique a été fournie par National Agricultural Library
Découvrez la collection de ce fournisseur de données dans AGRIS