Abstract:
:We have engineered Escherichia coli to overproduce saturated and monounsaturated aliphatic methyl ketones in the C₁₁ to C₁₅ (diesel) range; this group of methyl ketones includes 2-undecanone and 2-tridecanone, which are of importance to the flavor and fragrance industry and also have favorable cetane numbers (as we report here). We describe specific improvements that resulted in a 700-fold enhancement in methyl ketone titer relative to that of a fatty acid-overproducing E. coli strain, including the following: (i) overproduction of β-ketoacyl coenzyme A (CoA) thioesters achieved by modification of the β-oxidation pathway (specifically, overexpression of a heterologous acyl-CoA oxidase and native FadB and chromosomal deletion of fadA) and (ii) overexpression of a native thioesterase (FadM). FadM was previously associated with oleic acid degradation, not methyl ketone synthesis, but outperformed a recently identified methyl ketone synthase (Solanum habrochaites MKS2 [ShMKS2], a thioesterase from wild tomato) in β-ketoacyl-CoA-overproducing strains tested. Whole-genome transcriptional (microarray) studies led to the discovery that FadM is a valuable catalyst for enhancing methyl ketone production. The use of a two-phase system with decane enhanced methyl ketone production by 4- to 7-fold in addition to increases from genetic modifications.
journal_name
Appl Environ Microbioljournal_title
Applied and environmental microbiologyauthors
Goh EB,Baidoo EE,Keasling JD,Beller HRdoi
10.1128/AEM.06785-11subject
Has Abstractpub_date
2012-01-01 00:00:00pages
70-80issue
1eissn
0099-2240issn
1098-5336pii
AEM.06785-11journal_volume
78pub_type
杂志文章abstract::A vineyard isolate of the yeast Saccharomyces cerevisiae, UCD932, was identified as a strain producing little or no detectable hydrogen sulfide during wine fermentation. Genetic analysis revealed that this trait segregated as a single genetic determinant. The gene also conferred a white colony phenotype on BiGGY agar ...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.01666-10
更新日期:2010-12-01 00:00:00
abstract::Acetaldehyde is a toxic compound produced by Saccharomyces cerevisiae cells under several growth conditions. The adverse effects of this molecule are important, as significant amounts accumulate inside the cells. By means of global gene expression analyses, we have detected the effects of acetaldehyde addition in the ...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/aem.70.4.1913-1922.2004
更新日期:2004-04-01 00:00:00
abstract::Although several microorganisms that produce and degrade methanethiol (MT) and dimethyl sulfide (DMS) have been isolated from various habitats, little is known about the numbers of these microorganisms in situ. This study reports on the identification and quantification of microorganisms involved in the cycling of MT ...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.67.3.1044-1051.2001
更新日期:2001-03-01 00:00:00
abstract::Leptospirosis, an emerging zoonotic disease, remains poorly understood because of a lack of genetic manipulation tools available for pathogenic leptospires. Current genetic manipulation techniques include insertion of DNA by random transposon mutagenesis and homologous recombination via suicide vectors. This study des...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.00173-15
更新日期:2015-05-01 00:00:00
abstract::The growth of Vibrio parahaemolyticus in a liquid medium was compared with that of human fecal flora and estuarine flora. No marked differences were noted between growth at 25 and 37 degrees C for V. parahaemolyticus. However, the marine organisms were strongly inhibited when incubated at 37 degrees C. Incubation for ...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.46.5.1234-1235.1983
更新日期:1983-11-01 00:00:00
abstract::This is the first description, to our knowledge, of the distribution of human polyomavirus and simian virus 40 (SV40) in urban sewage. Using a nested-PCR procedure, we report the detection of human polyomaviruses JC virus (JCV) and BK virus (BKV) but not SV40 in a high percentage of urban sewage samples obtained from ...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/aem.66.1.238-245.2000
更新日期:2000-01-01 00:00:00
abstract::A census of clean room surface-associated bacterial populations was derived from the results of both the cloning and sequencing of 16S rRNA genes and DNA microarray (PhyloChip) analyses. Samples from the Lockheed Martin Aeronautics Multiple Testing Facility (LMA-MTF), the Kennedy Space Center Payload Hazard and Servic...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.01073-09
更新日期:2009-10-01 00:00:00
abstract::A dense exopolysaccharide (EPS) matrix is crucial for cyanobacterial survival in terrestrial xeric environments, in which cyanobacteria undergo frequent expansion and shrinkage processes during environmental desiccation-rehydration cycles. However, it is unclear how terrestrial cyanobacteria coordinate the structural ...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.01619-17
更新日期:2017-10-31 00:00:00
abstract::Recent physiological work has shown that the filamentous euendolithic cyanobacterium Mastigocoleus testarum (strain BC008) is able to bore into solid carbonates using Ca²⁺-ATPases to take up Ca²⁺ from the medium at the excavation front, promoting dissolution of CaCO₃ there. It is not known, however, if this is a wides...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.06633-11
更新日期:2012-01-01 00:00:00
abstract::Understanding of functional diversity of microbial populations has lagged description of their molecular diversity. Differences in substrate specificity, kinetics, products, and regulation can dramatically influence phenotypic variation among closely related strains, features that are missed when the strains studied a...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.01905-13
更新日期:2013-11-01 00:00:00
abstract::Caldalkalibacillus thermarum strain TA2.A1 grew in pH-controlled batch culture containing a fermentable growth substrate (i.e., sucrose) from pH 7.5 to 10.0 with no significant change in the specific growth rate, suggesting that this bacterium was a facultative alkaliphile. However, when strain TA2.A1 was grown on a n...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.01639-09
更新日期:2009-12-01 00:00:00
abstract::The sediment-water interface in Halifax Harbor supports a microbial population of 6.95 x 10 cells per g (dry weight). As determined by the standard technique of suspending subsamples in filtered seawater, the uptake of added glutamic acid by this population is 113.5 ng g (dry weight) h. An alternate technique was deve...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.45.6.1761-1766.1983
更新日期:1983-06-01 00:00:00
abstract::Three soilborne viruses transmitted by Polymyxa betae KESKIN in sugar beet have been described: Beet necrotic yellow vein virus (BNYVV), the agent of rhizomania, Beet soilborne virus (BSBV), and Beet virus Q (BVQ). A multiplex reverse transcription-PCR technique was developed to simultaneously detect BNYVV, BSBV, and ...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/aem.69.4.2356-2360.2003
更新日期:2003-04-01 00:00:00
abstract::Mycobiota growing on food is often beneficial for the ripening and development of the specific flavor characteristics of the product, but it can also be harmful due to the production of undesirable compounds such as mycotoxins or antibiotics. Some of the fungi most frequently isolated from fermented and cured meat pro...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/aem.68.3.1211-1219.2002
更新日期:2002-03-01 00:00:00
abstract::Nonselected and natural populations of Escherichia coli from 12 animal sources and humans were examined for the presence and types of 14 tetracycline resistance determinants. Of 1,263 unique E. coli isolates from humans, pigs, chickens, turkeys, sheep, cows, goats, cats, dogs, horses, geese, ducks, and deer, 31% were ...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/aem.70.4.2503-2507.2004
更新日期:2004-04-01 00:00:00
abstract::Genetic optimizations to achieve high-level production of three different proteins of medical importance for humans, granulocyte-macrophage colony-stimulating factor (GM-CSF), interferon alpha 2b (IFN-alpha2b), and single-chain antibody variable fragment (scFv-phOx), were investigated during high-cell-density cultivat...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.01804-06
更新日期:2007-02-01 00:00:00
abstract::Listeria app, isolated from 13 of 129 (10%) corn silage samples, 21 of 76 (28%) hay silage samples, and 3 of 5 (60%) grass silage samples during a previous Vermont survey were subjected to automated ribotype (RT) analysis. The 13 positive corn silage samples contained 3 Listeria monocytogenes isolated (three RTs, incl...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.63.9.3695-3697.1997
更新日期:1997-09-01 00:00:00
abstract::The host range and transfer frequency of an IncP-1 plasmid (pKJK10) among indigenous bacteria in the barley rhizosphere was investigated. A new flow cytometry-based cultivation-independent method for enumeration and sorting of transconjugants for subsequent 16S rRNA gene classification was used. Indigenous transconjug...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.00013-06
更新日期:2006-10-01 00:00:00
abstract::Members of a group of marine bacteria that is numerically important in coastal seawater and sediments were characterized with respect to their ability to transform organic and inorganic sulfur compounds. Fifteen strains representing the Roseobacter group (a phylogenetic cluster of marine bacteria in the alpha-subclass...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.65.9.3810-3819.1999
更新日期:1999-09-01 00:00:00
abstract::Enrichment was performed to isolate organisms that could utilize reduced phosphorus compounds as their sole phosphorus sources. One isolate that grew well with either hypophosphite or phosphite was identified by 16S rRNA gene analysis as a strain of Alcaligenes faecalis. The genes required for oxidation of hypophosphi...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.71.1.290-296.2005
更新日期:2005-01-01 00:00:00
abstract::We investigated long-chain fatty acid (LCFA)-degrading anaerobic microbes by enrichment, isolation, and RNA-based stable isotope probing (SIP). Primary enrichment cultures were made with each of four LCFA substrates (palmitate, stearate, oleate, or linoleate, as the sole energy source) at 55 degrees C or 37 degrees C ...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.02053-06
更新日期:2007-02-01 00:00:00
abstract::During the summer of 1981, 3,887 sucrose-negative vibrios were isolated from seawater, sediment, plankton, and animal samples taken from 80 sites from Miami, Fla., to Portland, Maine. Of these, 4.2% were able to ferment lactose. The lactose-positive strains isolated from the various samples correlated positively with ...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.45.3.985-998.1983
更新日期:1983-03-01 00:00:00
abstract::Azospirillum spp. were shown to utilize both straw and xylan, a major component of straw, for growth with an adequate combined N supply and also under N-limiting conditions. For most strains examined, a semisolid agar medium was satisfactory, but several strains appeared to be capable of slow metabolism of the agar. S...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.49.2.423-428.1985
更新日期:1985-02-01 00:00:00
abstract::Six laboratories actively involved in water virology research participated in a methods evaluation study, conducted under the auspices of the American Society for Testing and Materials Committee on Viruses in the Aquatic Environment, Task Force on Drinking Water. Each participant was asked to examine the Viradel (viru...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.47.1.144-150.1984
更新日期:1984-01-01 00:00:00
abstract::The effect of salinity and growth temperature on the accumulation of intracellular organic solutes was examined in the hyperthermophilic archaeon Palaeococcus ferrophilus. The genus Palaeococcus represents a deep-branching lineage of the order Thermococcales, which diverged before Thermococcus and Pyrococcus. Palaeoco...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.71.12.8091-8098.2005
更新日期:2005-12-01 00:00:00
abstract::Accurate predictions of carbon and energy cycling rates in the environment depend on sampling frequencies and on the spatial variability associated with biological activities. We examined the variability associated with anaerobic biodegradation rates at two sites in an alluvial sand aquifer polluted by municipal landf...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.60.10.3632-3639.1994
更新日期:1994-10-01 00:00:00
abstract::To understand phage infection and host cell lysis mechanisms in pathogenic Salmonella, a novel Salmonella enterica serovar Typhimurium-targeting bacteriophage, SPN9CC, belonging to the Podoviridae family was isolated and characterized. The phage infects S. Typhimurium via the O antigen of lipopolysaccharide (LPS) and ...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.02279-13
更新日期:2014-01-01 00:00:00
abstract::The electron donor cytochrome b5 (CybE/Cyb5) fuels the activity of the ergosterol biosynthesis-related P450 enzymes/P450s by providing electrons to P450s to promote ergosterol biosynthesis. Previous studies reported that lack of Aspergillus fumigatus (A. fumigatus) CybE reduces the proportion of ergosterol in total st...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.02571-20
更新日期:2020-11-30 00:00:00
abstract::Eleven strains of an undescribed species of Clavispora fermented D-xylose directly to ethanol under aerobic conditions. Strain UWO(PS)83-877-1 was grown in a medium containing 2% D-xylose and 0.5% yeast extract, and the following results were obtained: ethanol yield coefficient (ethanol/D-xylose), 0.29 g g (57.4% of t...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.50.4.763-766.1985
更新日期:1985-10-01 00:00:00
abstract::Rsan-ver, a strain of Pseudomonas aeruginosa isolated at this department, was used for the development of a continuous process for biosurfactant production. The active compounds were identified as rhamnolipids. A final medium for production was designed in continuous culture by means of medium shifts, since the format...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.48.2.301-305.1984
更新日期:1984-08-01 00:00:00