Table 1.
Characteristics of the isolates
| Bacterial type and strain | Origin | Enrichment conditionsa | Phylum | Closest relative species (accession no.) | Similarity (%) | Tolerance (%)b |
|
|---|---|---|---|---|---|---|---|
| Butanol | Isobutanol | ||||||
| Butanol-tolerant bacteria isolated under aerobic conditions | |||||||
| CM4A | Grease-contaminated soil | 30°C/4 mo/4.0% | Firmicutes | Enterococcus faecalis (AB012212) | 99.6 | 3.5 | 4.0 |
| CM9A | Grease-contaminated soil | 30°C/9 mo/9.0% | Firmicutes | Rummeliibacillus pycnus (AB271739) | 98.4 | 2.0 | 2.5 |
| SK4A | Freshwater sediment | 30°C/3 mo/4.0% | Firmicutes | Bacillus amyloliquefaciens (AB255669) | 99.6 | 2.0 | 2.5 |
| SK4D | Freshwater sediment | 30°C/4 mo/4.0% | Firmicutes | Enterococcus faecalis (AB012212) | 99.6 | 2.5 | 3.0 |
| SK5A | Freshwater sediment | 30°C/7 mo/5.0% | Firmicutes | Enterococcus faecalis (AB012212) | 99.5 | 3.0 | 3.5 |
| SK7A | Freshwater sediment | 30°C/9 mo/7.0% | Firmicutes | Lysinibacillus xylanilyticus (FJ477040) | 98.5 | 2.5 | 3.0 |
| SK9A | Freshwater sediment | 30°C/9 mo/9.0% | Firmicutes | Brevibacillus reuszeri (AB112715) | 99.8 | 2.0 | 2.5 |
| FW5A | Vegetable waste | 30°C/2 days/0.5% | Firmicutes | Bacillus amyloliquefaciens (AB255669) | 97.9 | 2.0 | 2.5 |
| CP3A | Cabbage-field soil | 30°C/2 days/3.0% | Firmicutes | Bacillus mycoides (AB021192) | 98.3 | 2.5 | 3.0 |
| CY2C | Compost | 30°C/2 days/2.0% | Actinobacteria | Cellulosimicrobium cellulans (X83809) | 98.1 | 2.0 | 2.5 |
| Butanol-tolerant bacteria isolated under anaerobic conditions | |||||||
| GK3 | Thermophilic anaerobic digester | 37°C/5 mo/2.0% | Firmicutes | Garciella nitratireducens (AY176772) | 92.8 | 2.0 | 2.5 |
| GK5 | Thermophilic anaerobic digester | 55°C/4 mo/2.0% | Firmicutes | Coprothermobacter proteolyticus (X69335) | 98.8 | 2.0 | 2.0 |
| GK12 | Thermophilic anaerobic digester | 37°C/5 mo/2.0% | Firmicutes | Eubacterium cylindroides (L34617) | 91.2 | 3.0 | 3.5 |
| YN1 | Oil-contaminated soil | 37°C/5 mo/2.0% | Firmicutes | Caloribacterium cisternae (JF262044) | 96.7 | 2.0 | 2.0 |
| YN3 | Oil-contaminated soil | 37°C/5 mo/2.0% | Firmicutes | Hydrogenoanaerobacterium saccharovorans (EU158190) | 98.0 | 2.0 | 2.0 |
| YN5 | Oil-contaminated soil | 37°C/4 mo/2.0% | Firmicutes | Clostridium pasteurianum (FR870440) | 93.6 | 2.5 | 3.0 |
a
The conditions of the enrichment culturesare given as follows: temperature/culture period/final butanol concentration.
b
The values represent the maximum butanol or isobutanol concentration allowing growth and were based on three independent replicates. The temperature at which tolerance was tested was the same temperature used for enrichment.