| Autor: |
Otite SV; Lancaster Environment Centre, Lancaster University, Library Avenue, Lancaster LA1 4YQ, UK., Gandhi BP; Engineering Department, Lancaster University, Gillow Avenue, Lancaster LA1 4YW, UK., Agyabeng Fofie E; Lancaster Environment Centre, Lancaster University, Library Avenue, Lancaster LA1 4YQ, UK., Lag-Brotons AJ; Engineering Department, Lancaster University, Gillow Avenue, Lancaster LA1 4YW, UK., Ezemonye LI; Centre for Global Eco-Innovation Nigeria, University of Benin, Benin City P.O. Box 300313, Edo State, Nigeria.; Vice Chancellor's Office, Igbinedion University Okada, Benin City P.O. Box 0006, Edo State, Nigeria., Martin AD; Engineering Department, Lancaster University, Gillow Avenue, Lancaster LA1 4YW, UK., Pickup RW; Division of Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Furness Building, Lancaster LA1 4YG, UK., Semple KT; Lancaster Environment Centre, Lancaster University, Library Avenue, Lancaster LA1 4YQ, UK. |
| Abstrakt: |
The effects of the inoculum (anaerobic digestion effluent) to substrate (simulated food waste) ratio (ISR) 4.00 to 0.25 on putative pathogens and microbial kinetics during batch mesophilic anaerobic digestion were investigated. Red fluorescent protein labelled (RFPAKN132) Escherichia coli JM105 was introduced as a marker species, and together with the indigenous Clostridium sp., Enterococcus sp., Escherichia coli , and total coliforms were used to monitor pathogen death kinetics. Quantitative polymerase chain reaction was also used to estimate the bacterial, fungal, and methanogenic gene copies. All the ISRs eliminated E. coli and other coliforms (4 log 10 CFU/mL), but ISR 0.25 achieved this within the shortest time (≤2 days), while ISR 1.00 initially supported pathogen proliferation. Up to 1.5 log 10 CFU/mL of Clostridium was reduced by acidogenic conditions (ISR 0.25 and 0.50), while Enterococcus species were resistant to the digestion conditions. Fungal DNA was reduced (≥5 log 10 copies/mL) and was undetectable in ISRs 4.00, 2.00, and 0.50 at the end of the incubation period. This study has demonstrated that ISR influenced the pH of the digesters during batch mesophilic anaerobic digestion, and that acidic and alkaline conditions achieved by the lower (0.50 and 0.25) and higher (4.00 and 2.00) ISRs, respectively, were critical to the sanitisation of waste. |
