Changes to the rumen bacterial population of sheep with the addition of 2,4,6-trinitrotoluene to their diet

Abstract

Previous work has shown that bacterial isolates from the sheep rumen are capable of detoxifying 2,4,6-trinitrotoluene (TNT) into polar constituents. In this study, the dietary effects of TNT on the sheep rumen microbial community were evaluated using molecular microbiology ecology tools. Rumen samples were collected from sheep fed with and without TNT added to their diet, genomic DNA was extracted, and the 16S rRNA-V3 gene marker was used to quantify changes in the microbial population in the rumen. Control and treatment samples yielded 533 sequences. Phylogenetic analyses were performed to determine the microbial changes between the two conditions. Results indicated the predominant bacterial populations present in the rumen were comprised of the phyla Firmicutes and Bacteroidetes, irrespective of presence/absence of TNT in the diet. Significant differences (P < 0.001) were found between the community structure of the bacteria under TNT (-) and TNT (+) diets. Examination of the TNT (+) diet showed an increase in the clones belonging to family Ruminococcaceae, which have previously been shown to degrade TNT in pure culture experiments.

Biochemical and Microbial Analysis of Ovine Rumen Fluid Incubated with 1,3,5-Trinitro-1,3,5-triazacyclohexane (RDX)

“…These results correlate well with the other published research that has characterized the rumen using the 16S-based gene marker [16,30,38,43]. Evaluations of ruminal microbial communities in cattle [16,38,43], sheep [24,31] and some wild ruminants [4,28] have shown them to be dominated by low GC Gram-positive bacteria (LGCGPB), particularly those related to the broad genus Clostridium.…”

“…Although ruminants consume forage as primary mode of nutrition, they possess diverse microflora that has been used to help detoxify several plant toxins such as pyrrolizidine alkaloid (PA) [32], oxalate [3], nitropropanol [5], dihydroxypyridine [13], and munition such as TNT [12,31] and RDX [15].…”

“…The animal rumen has been relatively well characterized in terms of its physiology [22]. Ruminants have tremendous potential in degrading or detoxifying numerous substrates ranging from grass-based carbohydrates to munitions [12,15,31] due to their anaerobic ecosystem and strong metabolic potential due to the diversity of microbes. Moreover, ruminants could be used as ''bio-reactors on hooves'' when combined with phytoremediation, using cool season grasses, thus presenting an easy accesses to in situ-based remediation [15].…”

Bacterial community in the rumen of Tibetan sheep and Gansu alpine fine-wool sheep grazing on the Qinghai-Tibetan Plateau, China

“…Cunha et al (2011) studied the rumen microbiome community structure in goats from the semiarid region of Brazil and concluded that the proportions of Firmicutes and Bacteroidetes present in the rumen liquid were 56.3% and 37.9%, respectively. In those sheep fed a grass hay or alfalfa mixture, the predominant microbial communities belonged to Firmicutes (approximately 44-45%) and Bacteroidetes (about 43%) (Koike et al, 2004;Perumbakkam et al, 2011). However, in dairy sheep fed marine algae, changes due to the addition of marine algae to the diet were observed, and the proportions of Firmicutes and Bacteroidetes were 13-26% and 69-77%, respectively (Castro-Carrera et al, 2014;Chaucheyras-Durand and Ossa, 2014).…”

Anaerobic Methyl tert -Butyl Ether-Degrading Microorganisms Identified in Wastewater Treatment Plant Samples by Stable Isotope Probing

“…This observation is consistent with the current study in that no MTBE biodegradation under the sulfate-and nitrate-amended conditions (no methane was produced), although they were seeded from the same inocula. Ruminococcaceae were also linked with 2,4,6-trinitrotoluene (TNT) degradation in a recent study (42).…”