The cell suspension was sonicated (8 × 30 s, Sonicator Heat system with 50% duty cycle) on ice in the presence of protease inhibitor PMSF. The cell lysate was centrifuged at 14 000 g for 30 min at 4 °C to remove cell debris. The clear supernatant was loaded on a Q-Sepharose ion exchanger. The cleared supernatant was applied to a 2 cm × 10 cm column packed with an anion-exchanger, Q-Sepharose, previously equilibrated with buffer A. The flow through was collected and passed five to six times from the column. The protein fraction bound to the matrix (including

the target protein) was eluted with 100 mL of a linear 0–1 M NaCl gradient, prepared in the same buffer. The fractions were then run on a 10% sodium dodecyl sulphate (SDS) gel to determine which

fractions contain the full-length squalene synthase. The fractions Avasimibe mouse showing SSN activity were pooled and applied on a phenyl superose column for further purification. The protein sample from the preceding step was saturated with 25% ammonium sulphate [(NH4)2SO4] Venetoclax in vivo in buffer B (20 mM Tris, 175 mM NaCl, 2 mM EDTA, 5 mM BME, 1% Tween 80) and was applied on pre-equilibrated phenyl superose [with 25% (NH4)2SO4-saturated buffer B]. The column was washed successively with buffer B containing 20%, 15%, 10% and 5% saturated (NH4)2SO4. Finally, the protein was eluted with buffer B. The fractions showing squalene old synthase activity were combined and used for further studies. Protein samples were separated by 10% SDS-PAGE and transferred to a nitrocellulose

membrane. SDS-polyacrylamide gels were stained with Coomassie brilliant blue R-250. Western blots were probed with hexahistidine antibody, following the manufacturer’s recommendation, and immunoreactive proteins were visualized using chemiluminescent substrate Lumigen. Squalene synthase activity of the recombinant protein was determined as reported by Sealey-Cardona et al., 2007. The catalytic activity of SSN was assayed by measuring the conversion of [3H] FPP to [3H] squalene. Final assay concentrations were 50 mM morpholinepropanesulfonic acid–NaOH buffer (pH 7.4), 20 mM MgCl2, 5 mM 3-[(3-cholamidopropyl)-dimethylammonio]-1-propanesulfonate, 1% Tween 80, 10 mM dithiothreitol, 0.025 mg mL1 of bovine serum albumin, 0.25 mM NADPH, 0.10 mg of recombinant protein mL−1 and different concentrations of FPP. The final volume of the reaction was 200 μL. After incubation at 37 °C for 5 min, 40 μL of 10 M NaOH was added, followed by 10 μL of a mixture (50 : 1) of 70% ethanol and squalene. The resulting mixtures were mixed vigorously by vortexing, and then 10-μL aliquots were applied to 2.5 × 10-cm channels of a silica gel thin-layer chromatogram, and the newly formed squalene was separated from unreacted substrates by chromatography in toluene–ethyl acetate (9 : 1). The region of each chromatogram from 2 cm below the squalene band (Rf=0.

These results demonstrate a sharp contrast in the responses of D. vulgaris to low and high levels of H2O2, by analogy to data between 0.1% oxygen exposure selleck chemicals llc and air stress (Fournier et al., 2006; Mukhopadhyay et al., 2007). Our results show that the primary response of D. vulgaris Hildenborough to H2O2 stress is finely regulated.

In addition to regulating genes directly involved in H2O2 detoxification such as the PerR regulon members, nigerythrin and thiol peroxidase-encoding genes, H2O2 also regulates the expression of sod and sor genes, involved in the elimination of superoxide anions. All these genes thus belong to the H2O2 stimulon and are directly involved in the defense mechanisms that allow cells to counterbalance the toxic effects of H2O2 and its derived chemical species in low concentrations. This mechanism thus allows cells to adapt successfully to temporary ROS presence and to survive in a variety of natural biotopes that undergo Torin 1 molecular weight periodic exposure to oxidative conditions. It is noteworthy that the expression of all these genes is inversely regulated depending on

the H2O2 concentration, suggesting subtle and complicated regulation mechanisms of oxidative stress responses in D. vulgaris that need further studies to be completely characterized. This work was supported by the FEMS Research Fellowship to A.L.B. The authors acknowledge Y. Denis from the IMM Transcriptomic facilities for the helpful discussion on qRT-PCR. Sequences of primers used in the study. Please note: Wiley-Blackwell is not responsible for the content or functionality of any supporting materials supplied by the authors. Any queries (other than missing material) should be directed to the corresponding author Inositol monophosphatase 1 for the article. “
“Vanadium is a contaminant from steel additive and ship fuel in coastal and port areas, and its effect

on marine microbes remains largely unknown. We showed that vanadium accelerates transfer of the tetracycline resistance gene tet(M) from Photobacterium to Escherichia coli, and found a positive correlation between the concentration of vanadium in natural marine sediment and the rate of oxytetracycline resistance. These results suggest the possibility that vanadium may play a role in the preservation and horizontal transfer of antibiotic resistance genes in the marine environment. Vanadium (V) is used as a steel additive (Moskalyk & Alfantazi, 2003) and is contained in jet and ship fuels, which may be released into the air and oceans (Viana et al., 2008; Pondolfi et al., 2011). Oil combustion alone accounts for 91% of total worldwide atmospheric V emissions.

8% at months 12, 24, 36 and 48, respectively). Regarding plasma lipid levels (Fig. 1d and e) we did not observe significant changes during the follow-up period. We found hypercholesterolaemia (>200 mg/dL) in 9.5, 30.4, 21.7, Selleckchem PD-332991 14.3 and 13.3% of patients at months 0, 12, 24, 36 and 48, respectively, and hypertriglyceridaemia (>170 mg/dL) in 14.3, 8.3, 13, 4.5 and 0% of patients at the same time-points. Throughout follow-up, and especially at the end of the study, we found an increase in plasma resistin and significant increases in total plasminogen activator inhibitor type 1 (tPAI-1), adiponectin and leptin levels (P<0.05) (Fig.

1f–i). Regarding the leptin:adiponectin ratio, HOMA values and C-peptide levels, we observed a slight increase during the first few months on HAART followed by a moderate decrease or stabilization after 24 months on HAART (Fig. 1j–l). The median BMI did not change significantly during follow-up, with values being between 17.32 and 16.42. There were no children in the overweight and low-weight BMI categories. Target Selective Inhibitor Library Concerning diagnoses of lipoatrophy, 17 children had no lipoatrophy, three had mild lipoatrophy, five had moderate lipoatrophy and two had severe lipoatrophy. Overall, seven of the 27 patients (25.9%) had lipoatrophy with scores ≥2. Concerning lipohypertrophy, 16 children did not have lipohypertrophy, three had mild lipohypertrophy, five had moderate lipohypertrophy and three had severe

lipohypertrophy. Overall, eight of the 27 patients (29.6%) had lipohypertrophy with scores ≥2. By the end of the study, 12 of the 27 children (44.4%) had lipodystrophy. However, only three of the 27 children (11.1%) had both lipoatrophy and lipohypertrophy scores ≥2. We carried out a follow-up study in PI-naïve HIV-infected tuclazepam children on HAART for 4 years, and found an increase in adipokine levels. This increase could be related to the

direct effect of PIs on adipose tissue, which could contribute to an imbalance in lipid metabolism and spatial development of lipodystrophy and metabolic syndrome in HIV-infected patients [21]. The metabolic pathway and the cytokine profile accomplices in the development of lipodystrophy and lipoatrophy is very complex. Thus, we did not find any significant trend in adipokine kinetics that may be associated with the onset of lipodystrophy at the end of the study. Moreover, results did not differ between patients with complete HIV suppression and those failing therapy. Therefore, we cannot definitely conclude from these results that there is a direct effect of HAART on adipose tissue, but there is a trend that warrants further investigation in studies with another design. In the present study we used clinical assessments of lipodystrophy; Dual Energy X-ray Absortiometry (DEXA) scanning would have provided a more quantitative assessment of lean vs. fat mass (particularly visceral fat) and may have provided better insights into the potential relationship between fat changes and adipokine levels.

Across the UK, there have been some improvements, including more consistency in advice provision to patients though the use of standard operating procedures in pharmacies and through better training of technicians and counter assistants. However,

the patient often still remains a receptacle for the receipt of care with, in the main, having little involvement in their disease management. It is time therefore to explore new approaches to getting patients more involved in their care. Improving medication adherence, which still seems to be stuck at the very resistant 50% mark, is central, as is getting better warning systems in place for when a patient with a chronic illness is getting ‘out of control’ such that they can either modify their own treatment under guidance and/or seek or obtain help once certain triggers are flagged. Early intervention can often result in the prevention of expensive hospitalisations IWR-1 research buy and therefore ease the pressure on an already stretched secondary care system. The application of new monitoring and communication technology within healthcare is considered an innovative solution to the challenges

facing the health service, particularly as the population ages and the management of chronic illness becomes increasingly important. This ‘Connected Health’ concept, often involves the patient engaging in monitoring markers of disease control in their own home, with the data generated Akt inhibitor being transmitted to a central triage centre. Healthcare staff (often trained nurses) at the triage centre, provide patients with feedback regarding

the next steps to be taken by the patient if the measured parameters are outside the ‘normal’ limits. This type of approach has resulted in some notable success, particularly within the VA system in the USA. Work in this area to date has, however, largely ignored the potentially pivotal input of pharmacists and in particular community pharmacists who are the key healthcare professionals in helping chronically ill patients manage their medicines in their own home (including adhering to the complex regimens which are often prescribed). The lack of integration of the activities of the general practitioner and the community pharmacist within the Aprepitant primary care sector in the UK is still very evident and the pharmacist (or drug expert) often has little influence in disease management outside the secondary care sector. A technology supported ‘connected health’ approach involving the patient, the GP and the community pharmacist has the potential to lead to a much more integrated approach. Too often, however, the manufacturers of the home monitoring devices and the associated connectivity infrastructure used in the ‘connected health’ approach, forget that the primary healthcare system in the UK is complex and fragmented into small populations grouped around GP practices and community pharmacies.

nodosus. There was no significant difference between the mean colony diameter of the virulent strain UNE61 and its pnpA mutant. The C-terminal PNPase deletion resulted in a decrease in twitching motility in the virulent strain UNE64. This result was unexpected, and is similar to the decrease in protease thermostability resulting from the PNPase deletion in this strain. It is possible that PNPase acts as a virulence activator in this strain. Alternatively, a mutation

at a second site may have occurred during transformation. To confirm that the increase in twitching motility in the benign strain pnpA mutants was due to the C-terminal deletion of PNPase, the PNPase gene was reconstructed in two mutants of benign strain 2483. The suicide plasmid pSK8

(Fig. GSK3235025 solubility dmso 1) can undergo a double crossover at the pnpA and orf379 loci in the tetracycline-resistant mutants from strain 2483, to reconstruct an intact 5-FU solubility dmso pnpA gene, followed by intB. As a result of this event, the tetracycline resistance gene is lost, and the kanamycin resistance gene is introduced between intB and orf379 (Fig. 1c). Transformation of the C-terminal deletion mutants 2483D1 and 2483D2 with pSK81 resulted in approximately 200 kanamycin-resistant transformants. The transformation frequency of the mutants with C-terminal deletions was much greater than that of the parent strain, 2483. Thus, the decrease in PNPase activity was associated with increased competence, in contrast to Bacillus subtilis, where disruption of pnpA resulted in decreased competence (Luttinger et al., 1996). Knocking out the fimbrial subunit gene fimA in D. nodosus abolished natural competence (Kennan et al., 2001), and so it is likely that the type IV fimbriae are involved in DNA uptake and that the increased competence of mutants with C-terminal PNPase deletions is associated with their increased twitching motility. Kanamycin-resistant transformants can be obtained using plasmid pSK81 Cyclin-dependent kinase 3 by a variety of single or double crossover events. Of the 200 kanamycin-resistant transformants obtained, only three were sensitive to tetracycline. Southern

blot analysis (data not shown) was used to show that these three transformants, 2483D1R1, 2483D2R1 and 2483D2R2, had the desired arrangement at the pnpA locus, resulting in reconstruction of pnpA. In all three cases, the twitching motility of the strains with reconstructed pnpA genes was significantly less than that of the strains with C-terminal PNPase deletions, and was similar to that of the parent strains (Fig. 3b and c). These results strongly suggest that the observed increase in twitching motility of the tetracycline-resistant mutants was due to the C-terminal deletion of PNPase. For the seven D. nodosus strains tested, we have shown that PNPase activity is higher in benign strains than in virulent strains.

At a population level, ART may be potentially

important in reducing the incidence of HIV infection. ART is Selleckchem LDK378 usually started for the health benefit of the individual, but in certain circumstances, it may be beneficial to start ART to primarily reduce the risk of onward sexual transmission of HIV. ART is extremely cost-effective and compares favourably with the cost of management of many other chronic diseases. Estimates of the cost-effectiveness of ART have been assessed in studies in North America and Europe [11-13]. Their findings have been consistent with an estimated incremental cost-effectiveness ratio of about US$20 000 per quality adjusted life year for combination ART Veliparib clinical trial compared with no therapy based on drug costs and treatment patterns in the USA and Europe [14]. The number of people living with HIV in the UK continues to increase and by the end of 2010 was estimated to be 91 500 of whom 24% were undiagnosed. Of those diagnosed, 69 400 accessed HIV services in 2010 of whom 82% were on ART [5]. With ongoing HIV transmission, increased HIV testing and a reduction in the undiagnosed fraction, the number of people diagnosed with HIV and accessing HIV services will

continue to increase. It has been estimated that the annual population treatment and care costs rose from £104 million in 1997 to £483 million in Cyclic nucleotide phosphodiesterase 2006, rising to a projected annual cost of £721 million in 2013 [15]. It is likely this estimated projected cost is an overestimate

due to various factors, including earlier diagnosis and a lower proportion of patients with symptoms. However, in the current economic climate containing and reducing annual costs without affecting the current high standards of care and treatment outcomes will be an immense challenge to commissioners, healthcare professionals and patients alike. A collaborative approach is required. In the UK, higher annual treatment and care costs have been associated with late diagnosis and initiation of ART at lower CD4 cell counts than the BHIVA guidelines recommend [16, 17]. In addition to earlier diagnosis and initiation of ART, reducing inpatient episodes, decreasing drug toxicity, preventing HIV-associated co-morbidities and innovations in models of care are likely to have a beneficial effect on annual costs. However, the cost of antiretroviral (ARV) drugs remains the major factor contributing to treatment and care costs. With the future availability of generic drugs and the introduction of a standard tariff for HIV services (in England), clinicians and patients will be faced with difficult choices about the value and benefit of different ARV drugs.

Successful transfer of plasmids between strains in USA300 clone proves transduction is an effective

mechanism for spreading plasmids within the clone. Such events contribute to its evolution and to emergence of new multiple drug-resistant strains of this successful clone. Staphylococcus aureus is an important human pathogen causing both nosocomial and community-acquired infections ranging from minor superficial skin infections to life-threatening systemic diseases. Staphylococcus aureus USA300 is one of the S. aureus clones most widespread worldwide. Typically, USA300 strains are associated with infections occurring in the community, but, more recently, these strains have been reported to cause infection among patients in health care facilities (Tenover & Goering, 2009). The most noticeable check details feature of the USA300 genome is its rapid diversification and acquisition of different mobile genetic elements, including plasmids (Kennedy et al., 2008; Li et al., 2009). USA300 strains harbor a diverse set of plasmids with a broad spectrum of antibiotic resistance genes (Kennedy et al., 2010; Carpaij et al., 2011). The most common mechanism of horizontal gene transfer in S. aureus is apparently transduction, because there is a little evidence that transformation occurs and conjugative plasmids or transposons are not widespread in S. aureus (Lindsay, 2008). Many transduction experiments have been GPCR & G Protein inhibitor conducted intending

either to test the transduction ability of staphylococcal phages (Dowell & Rosenblum, 1962; Novick, 1990) or prove the mobility of variable genetic elements with genes encoding antibiotic resistance or toxins (Cohen & Sweeney, 1970; Ruzin et al., 2001; Nakaminami et al., 2007; Chen & Novick, 2009). Most clinically important human

strains of S. aureus harbor at least one prophage, the presence of which may affect the strain’s capability for gene transfer (Lindsay, 2008; Goerke et al., 2009). To date, however, only limited knowledge is available whether naturally occurring phages are able to mediate effective transfer of plasmids in vivo within the population of clinical S. aureus strains. The main aim of this study was to prove that the penicillinase and tetracycline resistance plasmids Florfenicol are efficiently transferred within the USA300 clone by transduction. According to our best knowledge, this is also the first work providing quantitative real-time PCR (qPCR) estimation of functional plasmids packaged in transducing particles in S. aureus. Five strains from the USA300 clone, designated 07/235, 07/759, 08/019, 08/629, and 08/986 (all isolated in Czech hospitals), were obtained from the National Reference Laboratory for Staphylococci, National Institute of Public Health, Prague. Their assignment to the USA300 clone was based on PCR screening for the arginine catabolic mobile element and lukF-PV and lukS-PV genes (Diep et al., 2006), spa typing (Shopsin et al.

Successful transfer of plasmids between strains in USA300 clone proves transduction is an effective

mechanism for spreading plasmids within the clone. Such events contribute to its evolution and to emergence of new multiple drug-resistant strains of this successful clone. Staphylococcus aureus is an important human pathogen causing both nosocomial and community-acquired infections ranging from minor superficial skin infections to life-threatening systemic diseases. Staphylococcus aureus USA300 is one of the S. aureus clones most widespread worldwide. Typically, USA300 strains are associated with infections occurring in the community, but, more recently, these strains have been reported to cause infection among patients in health care facilities (Tenover & Goering, 2009). The most noticeable www.selleckchem.com/products/abt-199.html feature of the USA300 genome is its rapid diversification and acquisition of different mobile genetic elements, including plasmids (Kennedy et al., 2008; Li et al., 2009). USA300 strains harbor a diverse set of plasmids with a broad spectrum of antibiotic resistance genes (Kennedy et al., 2010; Carpaij et al., 2011). The most common mechanism of horizontal gene transfer in S. aureus is apparently transduction, because there is a little evidence that transformation occurs and conjugative plasmids or transposons are not widespread in S. aureus (Lindsay, 2008). Many transduction experiments have been selleckchem conducted intending

either to test the transduction ability of staphylococcal phages (Dowell & Rosenblum, 1962; Novick, 1990) or prove the mobility of variable genetic elements with genes encoding antibiotic resistance or toxins (Cohen & Sweeney, 1970; Ruzin et al., 2001; Nakaminami et al., 2007; Chen & Novick, 2009). Most clinically important human

strains of S. aureus harbor at least one prophage, the presence of which may affect the strain’s capability for gene transfer (Lindsay, 2008; Goerke et al., 2009). To date, however, only limited knowledge is available whether naturally occurring phages are able to mediate effective transfer of plasmids in vivo within the population of clinical S. aureus strains. The main aim of this study was to prove that the penicillinase and tetracycline resistance plasmids Oxymatrine are efficiently transferred within the USA300 clone by transduction. According to our best knowledge, this is also the first work providing quantitative real-time PCR (qPCR) estimation of functional plasmids packaged in transducing particles in S. aureus. Five strains from the USA300 clone, designated 07/235, 07/759, 08/019, 08/629, and 08/986 (all isolated in Czech hospitals), were obtained from the National Reference Laboratory for Staphylococci, National Institute of Public Health, Prague. Their assignment to the USA300 clone was based on PCR screening for the arginine catabolic mobile element and lukF-PV and lukS-PV genes (Diep et al., 2006), spa typing (Shopsin et al.

As shown in Table 2, mutations in mefE-mel of the serotype 6B strains S15 and S125 resulted in a significant decrease in TEL-MIC to the level of ATCC 49619 (<0.015 μg mL−1), which is used as a standard drug-susceptible strain. EM-MICs were also reduced to the level of ATCC 49619 (<0.5 μg mL−1). It is therefore concluded that mefE-mel is the determinant solely responsible for reduced TEL susceptibility and EM resistance in these clinical isolates. The mefE-mel mutation in strain S88 (TEL-MIC 1 μg mL−1), harboring both mefE-mel and ermB, resulted in a moderate reduction in TEL-MIC to 0.12 μg mL−1. Independent disruption of

S88 ermB resulted in a similar effect on TEL susceptibility (MIC 0.12 μg mL−1). In selleck chemicals contrast, disruption of both the mefE-mel and the ermB determinants further reduced TEL-MIC to the level of ATCC 49619 (MIC<0.015 μg mL−1). Similar results were obtained when the mutants were constructed independently from strains S120 and

S43, which carry both mefE-mel and ermB elements. Taken together, the results suggest that reduced TEL susceptibility (TEL-MIC 1 μg mL−1) in S. Afatinib research buy pneumoniae may be caused by the acquisition of the mefE-mel element only and conferred additionally by the ermB element. The disruption of ermB resulted in drastic decreases in resistance to EM; MIC declined from >512 to 4 μg mL−1. However, the mefE-mel mutations did not significantly affect resistance. Additional mefE-mel mutations

in the ermB mutants reduced EM-MICs to the level of ATCC (MIC 0.5 μg mL−1). These results suggest that ermB is a predominant mechanism for high resistance to EM in the pneumococcal isolates harboring both ermB and mefE-mel determinants, although the efflux assembly confers low-level resistance. Sequence analyses of the five isolates revealed no mutations in 23S rRNA gene domains II or V. There were no mutations in the L4 ribosomal protein from any isolate, except that from strain S43, in which the S20N mutation was found (data not shown). No mutations were found in the L22 ribosomal protein from any isolate. It has been demonstrated that the mefE and mel carried by mega may be a part of Tn2009, a composite element in which mega is integrated into a Tn916-like transposon carrying tetM (Franke & Clewell, 1981; Del Grosso et al., 2004). The presence of tetM has been examined Montelukast Sodium in isolates S15, S36, S89, S105 and S125, which express tetracycline resistance (MICs 16 μg mL−1), using PCR with the primers TETM1 and TETM2 (Del Grosso et al., 2004). This primer set produced an amplicon of approximately 2.0 kb, indicating the presence of tetM. The linkage between mefE-mel and tetM in these strains was investigated by Southern hybridization based on the restriction cleavage map constructed from the sequence (accession number AF376746). In these five isolates, mefE-mel and tetM were in close proximity, as shown in Tn2009 (data not shown).

0 mm, Whatman, Maidstone, UK) which were positioned on the plates. The plates were then incubated at 30 °C

until t a clear-zone had completely formed. A CAT (EC 2.3.1.28) assay was performed as described by Shaw (1975). Two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) peptide analysis of the protein spots was conducted as previously described (Choi et al., 2009). In the genome of C. glutamicum ATCC13032, four ORFs, namely NCgl0275 (whcA), NCgl0574, NCgl0711 and NCgl0734 (whcE), encoding homologues of S. coelicolor WhiB protein are present. Among the four whiB-like genes, only whcE and whcA have been studied (Kim et al., 2005; Choi et al., 2009). As an ongoing study on C. glutamicum whiB-like genes, learn more we chose NCgl0574 for further analysis. This ORF encoded a putative 11 178-Da protein composed of 99 amino acids. The transcriptional start point of the gene, which was determined by 5′ RACE, was a G residue located 71 bp upstream from the presumed translational start site, ATG. The putative promoter sequences of TGTTGT (−10) and TCTGTT (−35) are possibly located in the region upstream of the transcriptional start point (Pátek et al., 2003; Pátek, 2005; Nešvera & Pátek, 2008). Among the known CHIR-99021 in vivo WhiB homologues, Mycobacterium smegmatis MC2155 WhiB3 (MSMEG_1831), M. tuberculosis H37Rv WhiB3 (i.e. WhmB, Rv3416) and S. coelicolor

A3(2) WhiD (SCO4767) show relatively high similarity of 67%, 67% and 61%, respectively. As with other WhiB-like proteins, a cysteine-rich motif (Cys-X29-Cys-X2-Cys-X5-Cys), which is typically found in redox-sensitive proteins, was present in the central region of the encoded protein (Alam et al., 2007; Choi et al., 2009; Singh

et al., 2009; Smith et al., Montelukast Sodium 2010). Based on these properties, we designated this corynebacterial gene whcB, as it was a homologue of mycobacterial whmB. To elucidate the function of whcB, we constructed a C. glutamicum ΔwhcB mutant and whcB-overexpressing cells (P180-whcB-carrying cells), and then monitored their growth properties on minimal or complex media. Promoter P180 generates overexpression of the fused gene, irrespective of the growth phase (Park et al., 2004). Overexpression of the whcB gene was confirmed by quantitative RT-PCR (data not shown). As shown in Fig. 1a, the wild-type and ΔwhcB mutant strains showed almost identical doubling times, which were 2 h on minimal media, suggesting a non-essential role of the gene for normal growth. However, cells carrying P180-whcB showed not only a retarded growth rate, with a doubling time of 2.6 h, but also a lower cellular yield (Fig. 1a). Such a growth difference was also observed in complex medium, but at a reduced scale (data not shown). Subsequently, we measured the expression profile of the whcB gene in the wild-type, which achieved three-fold increased expression in stationary phase as compared with the exponential growth phase (Fig. 2).