Bacterial community analysis of swine manure treated with autothermal thermophilic aerobic digestion

Abstract

Due to the environmental problems associated with disposal of livestock sludge, many stabilization studies emphasizing on the sludge volume reduction were performed. However, little is known about the microbial risk present in sludge and its stabilized products. This study microbiologically explored the effects of anaerobic lagoon fermentation (ALF) and autothermal thermophilic aerobic digestion (ATAD) on pathogen-related risk of raw swine manure by using culture-independent 16S rDNA cloning and sequencing methods. In raw swine manure, clones closely related to pathogens such as Dialister pneumosintes, Erysipelothrix rhusiopathiae, Succinivibrioan dextrinosolvens, and Schineria sp. were detected. Meanwhile, in the mesophilic ALF-treated swine manure, bacterial community clones closely related to pathogens such as Schineria sp. and Succinivibrio dextrinosolvens were still detected. Interestingly, the ATAD treatment resulted in no detection of clones closely related to pathogens in the stabilized thermophilic bacterial community, with the predominance of novel Clostridia class populations. These findings support the superiority of ATAD in selectively reducing potential human and animal pathogens compared to ALF, which is a typical manure stabilization method used in livestock farms.

A Unique Autothermal Thermophilic Aerobic Digestion Process Showing a Dynamic Transition of Physicochemical and Bacterial Characteristics from the Mesophilic to the Thermophilic Phase

“…Nevertheless, relatively little is known about the ATAD process compared with traditional treatments, including the activated-sludge process, composting process, and methane fermentation process (12). In particular, most reports focused on the analysis of bacterial community structures during the thermophilic phase of the ATAD process in either full-scale or lab-scale bioreactors (7,13,(15)(16)(17)(18)(19)(20). In this study, we dynamically monitored bacterial community structures from the mesophilic to thermophilic phases using a high-throughput sequencer with higher resolution than the PCR-DGGE method (6), and we elucidated the unique behaviors regarding the physicochemical parameters and bacterial community structures of the ATAD process for treating human excreta.…”

Treatment alternatives of slaughterhouse wastes, and their effect on the inactivation of different pathogens: A review

“…Under mesophilic AD conditions, a T90 value of 1·8 days was obtained for E. rhusiopathiae, while at 53°C, the T90 value was reduced to 1–2 h. A study conducted by Han et al (2011) investigated the effects of an anaerobic lagoon fermentation and an autothermal thermophilic aerobic digestion on bacterial pathogens contained in raw swine manure. E. rhusiopathiae was present in the raw manure, however was no longer detectable following a mesophilic anaerobic lagoon fermentation.…”

Nonpoint Source Pollution, Environmental Quality, and Ecosystem Health in China: Introduction to the Special Section

“…Manure application loading rates are typically gauged by N concentration, leading to potential P runoff and eutrophication of water bodies in agricultural areas. The impacts of manure treatment processes before application should also be examined in relation to pathogen survival (Han et al, 2011) and the transformation and degradation of EDCs. Studies have shown that the contamination risk of manure‐derived heavy metals in cultivated plants varies with soil characteristics (Hao et al, 2008b; Li et al, 2009).…”