共查询到20条相似文献,搜索用时 15 毫秒
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Background
Poly-β-hydroxybutyrate (PHB) mobilization in bacteria has been proposed as a mechanism that can benefit their host for survival under stress conditions. Here we reported for the first time that a stress-induced system enabled E. coli, a non-PHB producer, to mobilize PHB in vivo by mimicking natural PHB accumulation bacteria. 相似文献3.
T. Yasuda M. Waki K. Kuroda D. Hanajima Y. Fukumoto T. Yamagishi Y. Suwa K. Suzuki 《Journal of applied microbiology》2013,114(3):746-761
Aims
To investigate community shifts of amoA‐encoding archaea (AEA) and ammonia‐oxidizing bacteria (AOB) in biofilter under nitrogen accumulation process.Methods and Results
A laboratory‐scale rockwool biofilter with an irrigated water circulation system was operated for 436 days with ammonia loading rates of 49–63 NH3 g m?3 day?1. The AEA and AOB communities were investigated by denaturing gradient gel electrophoresis, sequencing and real‐time PCR analysis based on amoA genes. The results indicated that changes in abundance and community compositions occurred in a different manner between archaeal and bacterial amoA during the operation. However, both microbial community structures mainly varied when free ammonia (FA) concentrations in circulation water were increasing, which caused a temporal decline in reactor performance. Dominant amoA sequences after this transition were related to Thaumarchaeotal Group I.1b, Nitrosomonas europaea lineages and one subcluster within Nitrosospira sp. cluster 3, for archaea and bacteria, respectively.Conclusions
The specific FA in circulation water seems to be the important factor, which relates to the AOB and AEA community shifts in the biofilter besides ammonium and pH.Significance and Impact of the Study
One of the key factors for regulating AEA and AOB communities was proposed that is useful for optimizing biofiltration technology. 相似文献4.
Background
The Amazon molly (Poecilia formosa) is a small unisexual fish that has been suspected of being threatened by extinction from the stochastic accumulation of slightly deleterious mutations that is caused by Muller's ratchet in non-recombining populations. However, no detailed quantification of the extent of this threat is available. 相似文献5.
Miyako Kusano Atsushi Fukushima Masanori Arita Pär Jonsson Thomas Moritz Makoto Kobayashi Naomi Hayashi Takayuki Tohge Kazuki Saito 《BMC systems biology》2007,1(1):53-17
Background
Metabolites are not only the catalytic products of enzymatic reactions but also the active regulators or the ultimate phenotype of metabolic homeostasis in highly complex cellular processes. The modes of regulation at the metabolome level can be revealed by metabolic networks. We investigated the metabolic network between wild-type and 2 mutant (methionine-over accumulation 1 [mto1] and transparent testa4 [tt4]) plants regarding the alteration of metabolite accumulation in Arabidopsis thaliana. 相似文献6.
Huiping Zhu Robert M Cabrera Bogdan J Wlodarczyk Daniel Bozinov Deli Wang Robert J Schwartz Richard H Finnell 《BMC developmental biology》2007,7(1):128
Background
Heart anomalies are the most frequently observed among all human congenital defects. As with the situation for neural tube defects (NTDs), it has been demonstrated that women who use multivitamins containing folic acid peri-conceptionally have a reduced risk for delivering offspring with conotruncal heart defects [1–3]. Cellular folate transport is mediated by a receptor or binding protein and by an anionic transporter protein system. Defective function of the Folr1 (also known as Folbp1; homologue of human FRα) gene in mice results in inadequate transport, accumulation, or metabolism of folate during cardiovascular morphogenesis. 相似文献7.
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Background
Proline (Pro) accumulation is a widespread response of prokaryotic and eukaryotic cells subjected to osmotic stress or dehydration. When the cells are released from stress, Pro is degraded to glutamate by Pro-dehydrogenase (ProDH) and Pyrroline-5-carboxylate dehydrogenase (P5CDH), which are both mitochondrial enzymes in eukaryotes. While P5CDH is a single copy gene in Arabidopsis, two ProDH genes have been identified in the genome. Until now, only ProDH1 (At3g30775) had been functionally characterised. 相似文献9.
Y.‐H. Hsu S.R. Cook T.W. Alexander C.L. Klima Y.D. Niu L.B. Selinger T.A. McAllister 《Journal of applied microbiology》2013,114(6):1592-1603
Aims
This study aimed to characterize the impact of lytic and temperate bacteriophages on the genetic and phenotypic diversity of Mannheimia haemolytica from feedlot cattle.Methods and Results
Strictly lytic phages were not detected from bovine nasopharyngeal (n = 689) or water trough (n = 30) samples, but Myoviridae‐ or Siphoviridae‐like phages were induced from 54 of 72 M. haemolytica strains by mitomycin C, occasionally from the same strain. Phages with similar restriction fragment length polymorphism profiles (RFLP ≥70% relatedness) shared common host serotypes 1 or 2 (P < 0·000 1). Likewise, phages with similar RFLP tended to occur in genetically related host bacteria (70–79% similarity). Host range assays showed that seven phages from host serotypes 1, 2 and 6 lysed representative strains of serotypes 1, 2 or 8. The genome of vB_MhM_1152AP from serotype 6 was found to be collinear with P2‐like phage φMhaA1‐PHL101.Conclusions
Prophages are a significant component of the genome of M. haemolytica and contribute significantly to host diversity. Further characterization of the role of prophage in virulence and persistence of M. haemolytica in cattle could provide insight into approaches to control this potential respiratory pathogen.Significance and Impact of the Study
This study demonstrated that prophages are widespread within the genome of M. haemolytica isolates and emphasized the challenge of isolating lytic phage as a therapeutic against this pathogen. 相似文献10.
Background
With an accumulation of in silico data obtained by simulating large-scale biological networks, a new interest of research is emerging for elucidating how living organism functions over time in cells. 相似文献11.
Background
Cadmium (Cd) concentrations in durum wheat (Triticum turgidum L. var durum) grain grown in North American prairie soils often exceed proposed international trade standards. To understand the physiological processes responsible for elevated Cd accumulation in shoots and grain, Cd uptake and translocation were studied in seedlings of a pair of near-isogenic durum wheat lines, high and low for Cd accumulation in grain. 相似文献12.
Fate of Escherichia coli O145 present naturally in bovine slurry applied to vegetables before harvest,after washing and simulated wholesale and retail distribution
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M.L. Hutchison D. Harrison J.F. Heath J.M. Monaghan 《Journal of applied microbiology》2017,123(6):1597-1606
Aims
To determine the fate of Escherichia coli on vegetables that were processed through commercial wash treatments and stored under simulated retail conditions at 4°C or wholesale at fluctuating ambient temperatures (0–25°C, dependent on season).Methods and Results
Bovine slurry that was naturally contaminated with E. coli O145 was applied without dilution or diluted 1:10 using borehole water to growing potatoes, leeks or carrots. Manure was applied 1 week prior to harvest to simulate a near‐harvest contamination event by manure deposition or an application of contaminated water to simulate a flooding event or irrigation from a contaminated water source. At harvest, crops were contaminated at up to 2 log cfu g?1. Washing transferred E. coli into the water of a flotation tank used for potato washing and did not completely remove all traces of contamination from the crop. Manure‐contaminated potatoes were observed to contain 0·72 cfu E. coli O145 g?1 after processing and retail storage. Manure‐contaminated leeks harboured 0·73–1·55 cfu E. coli O145 g?1 after washing and storage. There was no cross‐contamination when leeks were spray washed. Washing in an abrasive drum resulted in less than perfect decontamination for manure‐contaminated carrots. There were five post‐distribution isolations from carrots irrigated with contaminated water 24 h prior to harvest.Conclusions
Standard commercial washing and distribution conditions may be insufficient to reliably control human pathogenic E. coli on fresh produce.Significance and Impact
Previous speculation that the cause of a UK foodborne disease outbreak was soil from imperfectly cleaned vegetables is plausible. 相似文献13.
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Background
Developing monocots that accumulate more vegetative tissue protein is one strategy for improving nitrogen-sequestration and nutritive value of forage and silage crops. In soybeans (a dicotyledonous legume), the vspA and B genes encode subunits of a dimeric vegetative storage protein that plays an important role in nitrogen storage in vegetative tissues. Similar genes are found in monocots; however, they do not accumulate in leaves as storage proteins, and the ability of monocot leaves to support accumulation of an ectopically expressed soybean VSP is in question. To test this, transgenic maize (Zea Mays L. Hi-II hybrid) lines were created expressing soybean vspB from a maize ubiquitin Ubi-1 promoter. 相似文献15.
Background
CUP-5 is a Transient Receptor Potential protein in C. elegans that is the orthologue of mammalian TRPML1. Loss of TRPML1 results in the lysosomal storage disorder Mucolipidosis type IV. Loss of CUP-5 results in embryonic lethality and the accumulation of enlarged yolk granules in developing intestinal cells. The embryonic lethality of cup-5 mutants is rescued by mutations in mrp-4, which is required for gut granule differentiation. Gut granules are intestine-specific lysosome-related organelles that accumulate birefringent material. This link between CUP-5 and gut granules led us to determine the roles of CUP-5 in lysosome and gut granule biogenesis in developing intestinal cells. 相似文献16.
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Christian Theilacker Irina Sava Patricia Sanchez-Carballo Yinyin Bao Andrea Kropec Elisabeth Grohmann Otto Holst Johannes Huebner 《BMC microbiology》2011,11(1):67
Background
Deletion of the glycosyltransferase bgsA in Enterococcus faecalis leads to loss of diglucosyldiacylglycerol from the cell membrane and accumulation of its precursor monoglucosyldiacylglycerol, associated with impaired biofilm formation and reduced virulence in vivo. Here we analyzed the function of a putative glucosyltransferase EF2890 designated biofilm-associated glycolipid synthesis B (bgsB) immediately downstream of bgsA. 相似文献18.
Background
The infection and virulence functions of diverse plant and animal pathogens that possess quorum sensing systems are regulated by N-acylhomoserine lactones (AHLs) acting as signal molecules. AHL-acylase is a quorum quenching enzyme and degrades AHLs by removing the fatty acid side chain from the homoserine lactone ring of AHLs. This blocks AHL accumulation and pathogenic phenotypes in quorum sensing bacteria. 相似文献19.
Brittany E. Harlow Michael D. Flythe Glen E. Aiken 《Journal of applied microbiology》2018,124(1):58-66
Aims
The objective was to determine the effect of the isoflavone biochanin A (BCA) on rumen cellulolytic bacteria and consequent fermentative activity.Methods and Results
When bovine microbial rumen cell suspensions (n = 3) were incubated (24 h, 39°C) with ground hay, cellulolytic bacteria proliferated, short‐chain fatty acids were produced and pH declined. BCA (30 μg ml?1) had no effect on the number of cellulolytic bacteria or pH, but increased acetate, propionate and total SCFA production. Addition of BCA improved total digestibility when cell suspensions (n = 3) were incubated (48 h, 39°C) with ground hay, Avicel, or filter paper. Fibrobacter succinogenes S85, Ruminococcus flavefaciens 8 and Ruminococcus albus 8 were directly inhibited by BCA. Synergistic antimicrobial activity was observed with BCA and heat killed cultures of cellulolytic bacteria, but the effects were species dependent.Conclusions
These results indicate that BCA improves fibre degradation by influencing cellulolytic bacteria competition and guild composition.Significance and Impact of the Study
BCA could serve as a feed additive to improve cellulosis when cattle are consuming high‐fibre diets. Future research is needed to evaluate the effect of BCA on fibre degradation and utilization in vivo. 相似文献20.
Anna Zaczek Anna Brzostek Ewa Augustynowicz-Kopec Zofia Zwolska Jaroslaw Dziadek 《BMC microbiology》2009,9(1):10-8