Vinyl acetate degradation byBrevibacillus agriisolated from a slightly aerated methanogenic reactor

Abstract

In a previous paper, the authors showed that a slight aeration of a methanogenic reactor treating wastewater from the manufacture of polymeric resins could improve its performance, by increasing or allowing the removal of some of its contaminants, including vinyl acetate (VA). This paper reports the isolation under aerobic conditions of a VA-biodegrading axenic culture (strain C1) retrieved from the sludge of a slightly aerated methanogenic reactor at 1 mg L(-1) d(-1) of dissolved oxygen (DO). The axenic culture obtained was phenotypically (morphology, biochemical properties, VA consumption kinetics) and phylogenetically characterized. It formed white colonies with a branched and flat morphology on solid medium. The cell morphology of the isolate was bacillus with round endings and flagellate. The cells could form chains and were stained Gram-negative. The isolate required simple nutritional elements and had a growth rate of 0.024 h(-1). The phylogenetical analysis showed that the aerobic bacterium was identified as Brevibacillus agri, with 99.3% similarity. The VA consumption kinetics in the methanogenic sludge were: volumetric consumption rate (rVA) of 1.74 +/- 0.2 mg L(-1) h(-1), maximum specific consumption rate (qVAmax) of 3.98 mg g(-1) volatile suspended solids (VSS) h(-1) and affinity constant (Ks) of 457.1 mg L(-1). The same parameters in the axenic culture were 1.69 +/- 0.04 mg L(-1) (h-1), 4.09 mg g(-1) dry weight h(-1) and 421.9 mg L(-1), respectively. These results show evidence that the aerobic isolated bacterium, identified as Brevibacillus agri, carried out the VA hydrolysis in the slightly aerated methanogenic sludge, which is the limiting step in the degradation of this compound.

Intestinal microbiota of mangrove red snapper (Lutjanus argentimaculatus Forsskål, 1775) reared in sea cages

“…B. agri have been isolated from oil field (Li, She, Zhang, Zheng, Li, Xia & Wang 2006) and bioreactors containing natural gas (Bothe, Møller Jensen, Mergel, Larsen, Jørgensen, Bothe & Jørgensen 2002), fish meal wastewater (Kim, Kim, Cho & Hong 2007) and industrial effluents (Lara‐Mayorga, Durán‐Hinojosa, Arana‐Cuenca, Monroy‐Hermosillo & Ramirez‐Vives 2010), indicating that this species was well adapted to different environments. In the present study, a sequence (MRS3) showed 99% identity to B. agri , yet phylogenetic analysis indicated that it belonged to Cyanobacteria and it was the dominant species in intestinal digesta.…”

Enzymes involved in vinyl acetate decomposition by Pseudomonas fluorescens PCM 2123 strain

“…So far, only few papers focused on vinyl acetate decomposition by microorganisms (Greń et al 2009; Greń et al 2011; Hatanaka et al 1989; Kasperczyk et al 2007; Lara-Mayorga et al 2010; Nieder et al 1990). Ability to metabolize vinyl acetate depends on the capacity for synthesis of carboxyl esterase (EC 3.1.1.1).…”

Biochemical and microbiological analysis of shea nut cake: A waste product from shea butter processing

“…B. agri has been studied and known to achieve optimum growth at pH 7 and temperature of 45°C with specific growth rate of 0.102 ± 0.015 h -1 (Kongpol et al, 2009). The B. agri has shown high level tolerance for toxic organic solvents such as vinyl acetate, n-tetradecane, cyclohexane, n-pentanol, nbutanol, iso-butanol, butyl acetate, ethyl acetate and fairly towards toluene (Kongpol et al, 2009;Mayorga et al, 2010). Thus, 4% of the isolates could be useful microorganisms for transforming xenobiotics for bioremediation of polluted environments.…”