Abstract
The thermophilic bacterium Bacillus thermoamylovorans produces highly heat-resistant spores that can contaminate food products, leading to their spoilage. Here, we present the whole-genome sequences of four B. thermoamylovorans strains, isolated from milk and acacia gum.
GENOME ANNOUNCEMENT
Bacillus thermoamylovorans is a facultative thermophilic, facultatively anaerobic, amylolytic bacterium that was isolated from palm wine and characterized first in 1995 (1). The species is being studied because of its ability to produce lactic acid (2) and a thermostable lipase (3) as well as to degrade sewage sludge (4) and plant biomass (5). The bacterium was also found to contaminate gelatin extracts (6) and has been isolated on dairy farms (7, 8). B. thermoamlyovorans forms spores (7) that are highly heat resistant; these can survive preservation treatments that are commonly used by the food industry, and upon germination and outgrowth, this can lead to food spoilage (8, 9).
Four strains of B. thermoamlyovorans, isolated from foodstuffs in which spoilage occurred, were subjected to next generation whole-genome sequencing. The isolates were cultured overnight in brain heart infusion (BHI) broth (Difco) supplemented with vitamin B12 at 50°C with shaking (220 rpm). After being harvested, the cell pellets were resuspended in SET buffer (75 mM NaCl, 25 mM EDTA, 20 mM Tris-HCl, pH 7.5). The cell suspensions were treated with lysozyme (2 mg/ml) and RNase (0.4 mg/ml) at 37°C for 30 min. Subsequently, the samples were incubated with proteinase K (0.5 mg/ml) and SDS (final concentration, 1%) at 55°C for 60 min. Genomic DNA was isolated from lysed cells by phenol-chloroform extraction and precipitation with isopropanol and sodium acetate (300 mM). Precipitated DNA was dissolved in TE buffer.
Nucleotide sequence accession numbers.
The genome sequences of the four Bacillus thermoamylovorans strains have been deposited as whole-genome shotgun projects at DDBJ/EMBL/GenBank under the accession numbers listed in Table 1.
TABLE 1.
B. thermoamylovorans sequenced strains and their sources
| Strain no.a | Source | Accession no. |
|---|---|---|
| B4064 | Acacia gum | JXLR00000000 |
| B4065 | Acacia gum | JXLS00000000 |
| B4166 | Milk | JXLT00000000 |
| B4167 | Milk | JXLU00000000 |
Numbers refer to strain collections at NIZO food research and University of Groningen (Molecular Genetics).
ACKNOWLEDGMENTS
We thank the NGS sequence facility of the University Medical Center of Groningen (UMCG) for performing the sequencing of the strains.
We thank Top Institute for Food and Nutrition for contributing to the funding of the project in theme 3: Safety and Preservation.
Footnotes
Citation Krawczyk AO, Berendsen EM, Eijlander RT, de Jong A, Wells-Bennik MHJ, Kuipers OP. 2015. Draft genome sequences of four Bacillus thermoamylovorans strains isolated from milk and acacia gum, a food ingredient. Genome Announc 3(2):e00165-15. doi:10.1128/genomeA.00165-15.
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