Isolation and survey of novel fluoroacetate-degrading bacteria belonging to the phylum Synergistetes

Abstract

Microbial dehalogenation of chlorinated compounds in anaerobic environments is well known, but the degradation of fluorinated compounds under similar conditions has rarely been described. Here, we report on the isolation of a bovine rumen bacterium that metabolizes fluoroacetate under anaerobic conditions, the mode of degradation and its presence in gut ecosystems. The bacterium was identified using 16S rRNA gene sequence analysis as belonging to the phylum Synergistetes and was designated strain MFA1. Growth was stimulated by amino acids with greater quantities of amino acids metabolized in the presence of fluoroacetate, but sugars were not fermented. Acetate, formate, propionate, isobutryate, isovalerate, ornithine and H2 were end products of amino acid metabolism. Acetate was the primary end product of fluoroacetate dehalogenation, and the amount produced correlated with the stoichiometric release of fluoride which was confirmed using fluorine nuclear magnetic resonance (19F NMR) spectroscopy. Hydrogen and formate produced in situ were consumed during dehalogenation. The growth characteristics of strain MFA1 indicated that the bacterium may gain energy via reductive dehalogenation. This is the first study to identify a bacterium that can anaerobically dehalogenate fluoroacetate. Nested 16S rRNA gene‐specific PCR assays detected the bacterium at low numbers in the gut of several herbivore species.

Amino Acid and Peptide Utilization Profiles of the Fluoroacetate-Degrading Bacterium Synergistetes Strain MFA1 Under Varying Conditions

“…Preliminary biochemical characterization of strain MFA1 was reported by Davis et al [19], but further investigation of the factors that influence its survival and growth in gut ecosystems is required. The primary aim of this study was to investigate the nutritional requirement of strain MFA1 with an emphasis on amino acid and peptide utilization under various culturing conditions, which may facilitate the establishment and maintenance of strain MFA1 in the rumen.…”

“…This bacterium is asaccharolytic and ferments amino acids for growth [19], which are characteristics shared across the Synergistetes phylum [6]. Moreover, strain MFA1 is capable of anaerobically degrading fluoroacetate, a toxic compound found in some Acacia plant species and heartleaf (Gastrolobium spp.)…”

“…bovine rumen and appears to be a low-abundance ubiquitous member of the gastrointestinal tracts of various herbivores [19]. This bacterium is asaccharolytic and ferments amino acids for growth [19], which are characteristics shared across the Synergistetes phylum [6].…”

“…The Synergistetes bacterium strain MFA1 is most closely related to members of the genera Synergistes and Cloacibacillus [19]. Strain MFA1 was isolated from the Electronic supplementary material The online version of this article (doi:10.1007/s00248-015-0641-4) contains supplementary material, which is available to authorized users.…”

Isolation, identification, and degradation performance of a PFOA-degrading strain

“…Schröder (2003) and Meesters and Schröder (2004) reported that PFOA was degraded under anaerobic conditions using activated sludge in a sewage treatment plant, but the degradation efficiency was low. There are many other reports on the bacterial degradation of PFCs such as fluorobenzene (Carvalho et al, 2005), fluoroanilin (Amorim et al, 2013), PFB (Hughes et al, 2011), fluoroacetate (Davis et al, 2012), perfluorohexylethanol (Dinglasan et al, 2004;Wang et al, 2009;Liu et al, 2010) and perfluorohexylsulfonate (Wang et al, 2011). Some naturally occurring microorganisms possess defluorinating enzymes that attack the C-F bond.…”