Abstract:
:Identifying and overcoming the limitations preventing efficient high-yield production of chemicals remain important tasks in metabolic engineering. In an attempt to rewire Corynebacterium glutamicum to produce ethanol, we attained a low yield (63% of the theoretical) when using resting cells on glucose, and large amounts of succinate and acetate were formed. To prevent the by-product formation, we knocked out the malate dehydrogenase and replaced the native E3 subunit of the pyruvate dehydrogenase complex (PDHc) with that from Escherichia coli, which is active only under aerobic conditions. However, this tampering resulted in a 10-times-reduced glycolytic flux as well as a greatly increased NADH/NAD+ ratio. When we replaced glucose with fructose, we found that the glycolytic flux was greatly enhanced, which led us to speculate whether the source of reducing power could be the pentose phosphate pathway (PPP) that is bypassed when fructose is metabolized. Indeed, after shutting down the PPP by deleting the zwf gene, encoding glucose-6-phosphate dehydrogenase, the ethanol yield on glucose increased significantly, to 92% of the theoretical. Based on that, we managed to rechannel the metabolism of C. glutamicum into d-lactate with high yield, 98%, which is the highest that has been reported. It is further demonstrated that the PPP-inactivated platform strain can offer high-yield production of valuable chemicals using lactose contained in dairy waste as feedstock, which paves a promising way for potentially turning dairy waste into a valuable product.IMPORTANCE The widely used industrial workhorse C. glutamicum possesses a complex anaerobic metabolism under nongrowing conditions, and we demonstrate here that the PPP in resting C. glutamicum is a source of reducing power that can interfere with otherwise redox-balanced metabolic pathways and reduce yields of desired products. By harnessing this physiological insight, we employed the PPP-inactivated platform strains to produce ethanol, d-lactate, and alanine using the dairy waste whey permeate as the feedstock. The production yield was high, and our results show that inactivation of the PPP flux in resting cells is a promising strategy when the aim is to use nongrowing C. glutamicum cells for producing valuable compounds. Overall, we describe the benefits of disrupting the oxidative PPP in nongrowing C. glutamicum and provide a feasible approach toward waste valorization.
journal_name
Appl Environ Microbioljournal_title
Applied and environmental microbiologyauthors
Shen J,Chen J,Solem C,Jensen PR,Liu JMdoi
10.1128/AEM.02114-20subject
Has Abstractpub_date
2020-11-24 00:00:00issue
24eissn
0099-2240issn
1098-5336pii
AEM.02114-20journal_volume
86pub_type
杂志文章abstract::A mixed methanogenic culture fed with glucose was perturbed with butyrate and formate to investigate the role of formate in the acetogenesis of butyrate. A free energy analysis suggests that formate rather than H(2) was the interspecies electron carrier for butyrate conversion into acetate for the culture studied. ...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.59.2.628-630.1993
更新日期:1993-02-01 00:00:00
abstract::Vibrio cholerae O1 in plankton samples collected from ponds and rivers between February 1987 and January 1990 in Matlab, Bangladesh, was detected by the fluorescent-monoclonal antibody (FA) technique. Samples were collected at sites which were monitored fortnightly (fixed sites) as well as at sites that were part of a...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.56.8.2370-2373.1990
更新日期:1990-08-01 00:00:00
abstract::Bacterial Halanaerobium strains become the dominant persisting microbial community member in produced fluids across geographically distinct hydraulically fractured shales. Halanaerobium is believed to be inadvertently introduced into this environment during the drilling and fracturing process and must therefore tolera...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.00018-19
更新日期:2019-05-30 00:00:00
abstract::Isolated rumen bacteria were examined for growth and, where appropriate, for their ability to degrade cellulose in the presence of the hydroxycinnamic acids trans-p-coumaric acid and trans-ferulic acid and the hydroxybenzoic acids vanillic acid and 4-hydroxybenzoic acid. Ferulic and p-coumaric acids proved to be the m...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.44.3.597-603.1982
更新日期:1982-09-01 00:00:00
abstract::The effective flux between phospholipids and neutral lipids is critical for a high level of biosynthesis and accumulation of very-long-chain polyunsaturated fatty acids (VLCPUFAs), such as arachidonic acid (ARA; 20:4n-6), eicosapentaenoic acid (EPA; 20:5n-3), and docosahexaenoic acid (DHA; 22:6n-3). Here we describe a...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.03250-12
更新日期:2013-03-01 00:00:00
abstract::In a batch of barley associated with field cases of mycotoxic porcine nephropathy and containing ochratoxin A and citrinin, the mycoflora were isolated by parallel incubation at 10 and 25 degrees C. Subsequently, the isolated cultures were checked for production of nephrotoxins (xanthomegnin, viomellein, ochratoxin, a...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.46.6.1311-1317.1983
更新日期:1983-12-01 00:00:00
abstract::An extracellular protein with strong absorption at 406 nm was purified from cell-free culture fluid of latex-grown Xanthomonas sp. strain 35Y. This protein was identical to the gene product of a recently characterized gene cloned from Xanthomonas sp., as revealed by determination of m/z values and sequencing of select...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.70.12.7388-7395.2004
更新日期:2004-12-01 00:00:00
abstract::Hot-water extracts of mesquite (Prosopis glandulosa) wood were assayed for their total carbohydrate, reducing sugar, and glucose content. These hydrolysates were then used as complete media for yeast growth. A total of 10 strains of yeasts were evaluated for their biomass production in the mesquite wood hydrolysates. ...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.52.2.385-387.1986
更新日期:1986-08-01 00:00:00
abstract::The insertion of a heterologous gene into commensal bacteria is a common technique to develop a delivery agent for vaccination and therapies, but the pleiotropic effects of genetic modifications need to be investigated before its use in practical applications. Although supplemental properties provided by the expressio...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.01916-08
更新日期:2009-05-01 00:00:00
abstract::Columns were packed with clean quartz sand, sterilized, and inoculated with different strains of bacteria, which multiplied within the sand at the expense of a continuous supply of fresh nutrient medium. The saturated hydraulic conductivity (HCsat) of the sand was monitored over time. Among the four bacterial strains ...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.58.5.1690-1698.1992
更新日期:1992-05-01 00:00:00
abstract::Magnetotactic bacteria comprise a phylogenetically diverse group that is capable of synthesizing intracellular magnetic particles. Although various morphotypes of magnetotactic bacteria have been observed in the environment, bacterial strains available in pure culture are currently limited to a few genera due to diffi...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.02124-09
更新日期:2010-03-01 00:00:00
abstract::Ammonia-oxidizing bacteria (AOB) are thought to contribute significantly to N2O production and methane oxidation in soils. Most of our knowledge derives from experiments with Nitrosomonas europaea, which appears to be of minor importance in most soils compared to Nitrosospira spp. We have conducted a comparative study...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.65.6.2679-2684.1999
更新日期:1999-06-01 00:00:00
abstract::Large surface-to-volume ratios provide optimal nutrient uptake conditions for small microorganisms in oligotrophic habitats. The surface area can be increased with appendages. Here, we describe chains of interconnecting vesicles protruding from cells of strain Hel3_A1_48, affiliating with Formosa spp. within the Flavo...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.00829-19
更新日期:2019-09-17 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::Concentrations of airborne coliform bacteria as high as 1.5 X 10(4) m-3 were observed 8 cm above anaerobically digested sewage sludge applied to a forest clearcut. Dry conditions and high wind speeds tended to favor aerosol generation. ...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.36.6.972-974.1978
更新日期:1978-12-01 00:00:00
abstract::Vortex flow filtration (VFF) was used to concentrate viruses and dissolved DNA from freshwater and seawater samples taken in Florida, the Gulf of Mexico, and the Bahamas Bank. Recoveries of T2 phage and calf thymus DNA added to artificial seawater and concentrated by VFF were 72.8 and 80%, respectively. Virus concentr...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.57.8.2197-2204.1991
更新日期:1991-08-01 00:00:00
abstract::A soil-inhabiting Fusarium proliferatum strain was capable of transforming or degrading nonlabeled and (sup14)C-labeled industrial, natural, and synthetic lignin. The mineralization rate per day (expressed as the percentage of added radioactivity recovered as to (sup14)CO(inf2)) was maximal during primary metabolism. ...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.63.9.3716-3718.1997
更新日期:1997-09-01 00:00:00
abstract::We determined the prevalences of Escherichia coli O157:H7 in feces, hide, and carcasses of meat goats at a U.S. processing plant. Prevalences were 11.1%, 2.7%, and 2.7%, respectively. Sixteen pulsed-field gel electrophoresis (PFGE) subtypes were identified among 49 E. coli O157:H7 isolates, some of which were present ...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.00772-13
更新日期:2013-07-01 00:00:00
abstract::In a medium containing ammonia, proteose peptone, and cysteine as nitrogen sources, 17 of 24 Bacteroidaceae strains, 3 of Selenomonas strains, 1 of 7 curved rods, 3 of 7 Spirochaetaceae strains, 8 of 20 Eubacterium strains, 8 of 13 Peptococcaceae strains, 3 of 4 Clostridium strains, 19 of 20 Enterobacteriaceae strains...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.39.1.30-35.1980
更新日期:1980-01-01 00:00:00
abstract::Butyrate is an important intermediate in the anaerobic degradation of organic matter. In sulfate-depleted environments butyrate is oxidized to acetate and hydrogen by obligate proton reducers, in syntrophic association with hydrogen-consuming methanogens. This paper describes two enrichments of endospore-forming bacte...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.50.5.1244-1250.1985
更新日期:1985-11-01 00:00:00
abstract::We analyzed the regional distribution of bulk heterotrophic prokaryotic activity (leucine incorporation) and selected single-cell parameters (cell viability and nucleic acid content) as parameters for microbial functioning, as well as bacterial and archaeal community structure in the epipelagic (0 to 200 m) and mesope...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.07962-11
更新日期:2012-05-01 00:00:00
abstract::Data from analyses of continuous culture fermentation of insoluble cellulose by Ruminococcus albus 7 were used to derive constants for the rate of cellulose hydrolysis and fermentation, growth yield, and maintenance. Cellulose concentration was 1% in the nutrient reservoir, and hydraulic retention times of 0.5, 1.0, 1...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.54.11.2660-2663.1988
更新日期:1988-11-01 00:00:00
abstract::Throughout four field trials, compost heaps covered with finished compost maintained temperatures under the physical covering that were ca. 7 to 15.5°C higher, resulting in rapid Escherichia coli O157:H7 reduction, than those of the heaps covered with fresh straw or left uncovered. Our results validated recommendation...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.02940-10
更新日期:2011-07-01 00:00:00
abstract::Hot and cold aqueous extracts were prepared from 22 commonly ingested fruits, vegetables, and seeds. When tested by agar diffusion, extracts from 13 and 10 of the foods formed precipitin bands with samples of normal rabbit serum and human saliva, respectively; extracts from four of the foods also reacted with antigen ...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.41.4.880-888.1981
更新日期:1981-04-01 00:00:00
abstract::A phosphocholine-substituted beta-1,3;1,6 cyclic glucan (PCCG), an unusual cyclic oligosaccharide, has been isolated from Bradyrhizobium japonicum USDA 110 (D. B. Rolin, P. E. Pfeffer, S. F. Osman, B. S. Swergold, F. Kappler, and A. J. Benesi, Biochim. Biophys. Acta 1116:215-225, 1992). Data presented here suggest tha...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.60.6.2137-2146.1994
更新日期:1994-06-01 00:00:00
abstract::Species diversity, phylogenetic affiliations, and environmental occurrence patterns of thiosulfate-oxidizing marine bacteria were investigated by using new isolates from serially diluted continental slope and deep-sea abyssal plain sediments collected off the coast of New England and strains cultured previously from G...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/aem.66.8.3125-3133.2000
更新日期:2000-08-01 00:00:00
abstract::The reduction of cytotoxicity in virus concentrates from environmental samples was accomplished by high-speed centrifugation and by filtration of the samples through positively charged depth filters. ...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.43.3.731-733.1982
更新日期:1982-03-01 00:00:00
abstract::Comparative genomic hybridizations have been used to examine genetic relationships among bacteria. The microarrays used in these experiments may have open reading frames from one or more reference strains (whole-genome microarrays), or they may be composed of random DNA fragments from a large number of strains (mixed-...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.01647-06
更新日期:2007-03-01 00:00:00
abstract::Copper appears to be influencing the distribution and abundance of phytoplankton in marine environments, and cyanobacteria are thought to be the most sensitive of the phytoplankton groups to copper toxicity. By using growth assays of phylogenetically divergent clades, we found that coastal strains of marine Synechococ...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.00271-09
更新日期:2009-08-01 00:00:00
abstract::Five strains of mesophilic, facultatively organotrophic, ore-leaching eubacteria were isolated from solfatara fields in Iceland and a uranium mine in the Federal Republic of Germany. The new organisms are aerobic gram-negative rods. They can use sulfidic ores or elemental sulfur as sole energy source, indicating that ...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.56.2.315-322.1990
更新日期:1990-02-01 00:00:00