Duplication of biosynthetic genes to increase the yield of corres

Duplication of biosynthetic genes to increase the yield of corresponding secondary metabolite is a practicable and successful approach. The introduction of cosmid pML48 containing partial compactin gene cluster into Penicillium citrinum 41520 enhanced compactin production (Abe et al., 2002). A large increase in nikkomycin production was obtained when an extra nikkomycin biosynthetic gene cluster was integrated into the genomic of Saccharopolyspora ansochromogenes (Liao et al., 2010). Partial duplication of

the moenomycin cluster in Saccharopolyspora ghanaensis also increased average moenomycin production (Makitrynskyy et al., 2010). In these cases, constructing and screening Selleck PR-171 the BAC or cosmid library was the routine method for obtaining

the biosynthetic gene cluster, which is time- Wnt assay and labor-consuming. In our study, the strategy of direct cloning based on Red/ET technology was applied to obtain the spinosyn biosynthetic gene cluster from the genomic DNA of S. spinosa, which is simple and convenient. This straightforward technique is particularly suitable for large DNA molecules and is therefore ideal for engineering PKS and non-ribosomal peptide synthetase pathways. The spinosyn-producing microorganism, S. spinosa, has been shown to be recalcitrant to genetic manipulation and gene transfer processes (Matsushima et al., 1994). A plasmid containing a large fragment of S. spinosa DNA can integrate at high frequencies into the S. spinosa chromosome apparently by homologous recombination, whereas a plasmid containing a small sequence (c. 2 kb) of

S. spinosa DNA integrated at low frequencies into the S. spinosa chromosome at one of two bacteriophage φC31 attB sites (Matsushima et al., 1994). Our previous Thiamet G experiments also showed low frequencies when the integrative vector pSET152 was used for conjugation from E. coli S17-1 to S. spinosa. Therefore, we only amplified the pUC replication origin, apramycin resistance gene, and oriT of RK2 from this plasmid as the linear cloning vector. The c. 18-kb spinosyn genes in plasmid pUCAmT-spn served as the homologous sequence and guided a single-crossover homologous recombination to generate stable, apramycin-resistant exconjugants with all the genes duplicated. HPLC results showed that the yield of spinosyns A and D was significantly greater in the exconjugants than in the parental strain. The exconjugants also produced three more substances which might be the minor spinosyn components. As previously described, during the early part of a spinosyn fermentation, S.

, 2008) Interestingly, a two-component regulator, ArcA, is known

, 2008). Interestingly, a two-component regulator, ArcA, is known to bind the PY promoter at a site www.selleckchem.com/products/BKM-120.html adjacent to the

predicted TraJ-binding site (Strohmaier et al., 1998). Thus, ArcA could be similar to PhoP in function. Other candidates that might play an auxiliary role in desilencing PY include TraY, which autoregulates its expression at the PY promoter (Silverman & Sholl, 1996), or another nucleoid-associated protein such as Lrp (Starcic-Erjavec et al., 2003). Moreover, because H-NS silencing is a result of nutritional stress, CRP could also be involved in desilencing PY because it also plays a role in activating conjugative transfer in the F-like plasmid, pRK100 (Starcic et al., 2003). Thus, TraJ does not act alone, but appears to alleviate H-NS silencing in cooperation with a number of other regulatory sensors. We would like to thank Sylvie Rimsky,

Universite Paris XI, for anti-H-NS antibodies. This work was supported by grant MT 11249 from the Canadian Institutes of Health Research (L.S.F.). “
“Department of Pharmacology and Systems Therapeutics, Mount Sinai School of Medicine, New York, NY, USA Multiple resistance and pH adaptation (Mrp) antiporters are widely distributed in various prokaryotes and have been reported to function as a hetero-oligomeric monovalent cation/proton antiporter, which exchanges a cytoplasmic monovalent cation (Na+, Li+, and/or K+) with extracellular H+. In many organisms, they are essential for survival in alkaline or saline environments. Here, we report that the Mrp antiporter click here from the thermophilic gram-negative bacterium, Thermomicrobium roseum, does not catalyze monovalent cation/proton antiport like the Mrp antiporters studied to date, but catalyzes Ca2+/H+ antiport in Escherichia coli membrane vesicles. The mrp operons encode unusual multi-subunit cation/proton antiporters (CPAs) which exchange cytoplasmic cations for extracellular H+(Hiramatsu

et al., 1998; Putnoky et al., 1998; Ito et al., 1999; Kosono et al., 1999, 2005; Dzioba-Winogrodzki et al., 2009). Multiple resistance and pH adaptation (Mrp) antiporters require multiple, distinct hydrophobic subunits for their activity and apparently must function as hetero-oligomeric selleck products complexes. By contrast, other prokaryotic secondary monovalent CPAs are single gene products (Hunte et al., 2005; Kajiyama et al., 2007; Morino et al., 2008). Because of their structural features, Mrp antiporters are classified in the Transporter Database as a discrete CPA3 family (Saier et al., 1999). Mrp antiporters and their homologues are widespread among bacteria and archaea (Swartz et al., 2005), in which they often play indispensable roles in adaptation to alkaline or saline conditions as well as roles in pathogenicity (Kosono et al., 2005). Thus far, Mrp antiporters have been shown to catalyze efflux of Na+, Li+, and K+ in different combinations.

These results provide an insight into the degradation mode of the

These results provide an insight into the degradation mode of the enzyme, which may preferentially cleave at the α-1,4-linkage adjacent to nonreducing ends, showing the β-amylase

activity. The β-amylase showed a activity over a wide temperature range (30–90 °C), pH range (4.0–12.0), and NaCl concentrations (0–20%), with an optimum at 70 °C, pH 10.0% and 10% NaCl (Fig. 4). The thermal stability profile indicated that the enzyme was highly stable at temperatures below 70 °C after 24-h incubation, but was inactivated at 90 °C (Fig. 4a). Also, the β-amylase showed good pH stability retaining more than 80% activity in the pH range 6.0–11.0 (Fig. 4b). Furthermore, it was highly stable at NaCl concentrations between 2.5% and 20%, and more than 70% activity retained Selleck FDA approved Drug Library after dialysis in the absence of NaCl (Fig. 4c). As shown in Table 1, the metal ions tested did not affect or slightly inhibit the amylase activity. The effect of enzyme inhibitors indicated that DEPC, PAO and EDTA completely inactivated

the enzyme, but PMSF and β-mercaptoethanol had no significant effect on its activity. Moreover, more than 78% activity of the amylase retained after incubation with surfactants, such as SDS, Triton X-100, and Tween-80. Optimal activity of the protease was found to be at 80 °C, pH 10.0% and 12.5% NaCl (Fig. 4). It was highly stable at temperatures below 70 °C after 24-h incubation, but was inactivated at higher temperatures (Fig. 4a). Meanwhile, the protease showed good

stability in a broad pH range (6.0–11.0), which retained more than 70% Ibrutinib activity (Fig. 4b). As shown in Fig. 4c, about 82% activity lost in the absence of NaCl, but 70% activity retained under high salinity conditions (20%). Moreover, the protease was highly stable at NaCl concentrations between 2.5% and 20%. None of the metal ions was found to enhance the protease activity, and about 80% activity lost in the presence of Hg2+. EDTA and β-mercaptoethanol had no significant effect on the enzyme activity. However, complete inhibition of the protease was shown by PMSF, DEPC, and PAO. In addition, more than 85% activity retained after incubation with surfactants tested (Table 1). As shown in Table 2, no complete inactivation of both enzymes was observed in the presence of organic solvents tested. Nintedanib (BIBF 1120) More than 90% of the enzyme activity retained after incubation with DMSO, acetonitrile, ethanol, and acetone. Interestingly, ethanol and acetone even increased the amylase activity to 117.4% and 118.9%, respectively, and DMSO and ethanol also stimulated the protease activity (110.8% and 110.2%). The half-lives of both enzymes were drastically decreased in the presence of organic solvents with log Pow ≥ −0.24, but in the presence of organic solvents with lower log Pow, their half-lives were longer than in the absence of the solvents.

Good prognostic markers can be unreliable surrogates even if the

Good prognostic markers can be unreliable surrogates even if the association between clinical outcome and marker changes is the same for all drugs, as the relative importance of other mechanisms of their action, including adverse events, may vary among drugs [14]. In fact, the major meta-analysis assessing the surrogacy of 24-week changes in CD4 cell count and plasma viral load for disease progression to 2 years

[15] found that these markers were imperfect surrogate endpoints, explaining some but overall relatively little clinical risk. These findings were supported by detailed analyses of the Delta trial [16], and a 47% reduction in risk of AIDS/death despite only moderate impact on HIV RNA in the first trial

of ritonavir-containing combination Selleck STA-9090 therapy [17,18]. A recent review examining the magnitude of the effect of changes in CD4 cell Temsirolimus nmr count, HIV RNA and progression to AIDS or death also noted that, within short-term clinical trials, it was not possible to estimate the proportion of the effect of treatment on clinical outcomes associated with such surrogate endpoints [19]. Of note, NORA in fact found reverse relationships between abacavir vs. nevirapine and clinical vs. laboratory markers, rather than a relationship with laboratory markers and no relationship with clinical outcome as noted for lopinavir/ritonavir vs. efavirenz (both with zidovudine/lamivudine) in a recent ART Cohort Collaboration analysis [11]. Nevertheless,

antiretroviral drugs are licensed primarily on the basis of their effect on HIV RNA, not assuming that this is a true surrogate for clinical outcome, but as a pragmatic decision as switch to second-line ART HSP90 occurs long before clinical disease progression in resource-rich settings. There are several possible reasons why participants receiving abacavir-containing combination ART might have done better clinically. The significantly greater toxicity of nevirapine could indirectly have led to more clinical events, for example because of lower adherence (although this might have been expected to have had greater impacts on viral load and CD4 cell counts). Against this, we found no evidence of poorer adherence with nevirapine, there was no clear relationship between toxicity and cause of death (reviewed by an independent committee blinded to treatment allocation), and there was only a weak nonsignificant trend towards more ART modifications in the nevirapine group. NORA was designed as a blinded safety study: given the potential for abacavir hypersensitivity reactions, all participants were very closely monitored and it is extremely unlikely that important toxicity was missed. More abacavir substitutions with clinically superior drugs could have been made because of poorer immunological/virological responses.

Ina168m95-1 contains a conserved Occan element, named Occanm95-1,

Ina168m95-1 contains a conserved Occan element, named Occanm95-1, between sequences homologous to the 5′-flanking region of Occan3A3

and the 3′-flanking region of Occan9E12. In addition, sequence polymorphisms indicated a homologous recombination between Occan3A3 and Occan9E12, which resulted in Occanm95-1. Based on these observations, we propose the hypothesis that homologous recombination in the two Occan elements leads to the deletion of AVR-Pia in Ina168m95-1. Selleckchem AZD1208
“The cuticle of plants that covers the epidermis of cells, an interface between the fruit and the environment, has an important role to play in fruit quality because it prevents water loss and mechanical damage while simultaneously forming a barrier as it prevents phytopathogens from entering the fruit. All these factors give rise to flaws in the appearance of the fruit, thus contributing to marketing problems in the form of financial loss. In the search for solutions to some of these problems, certain biocontrolling yeasts have been introduced

in the last few years. In the study described here, the changes observed on the surface of the whole tomato were evaluated in vivo during the first 72 h after inoculation by spraying Candida guilliermondii yeast onto the fruit’s surface. The measurements were taken on a nanometric scale using atomic force microscopy; images were created in both contact and tapping modes. The results showed diminished roughness Lapatinib chemical structure of the surface, which could contribute to reduced phytopathogen

adherence due to the thinner contact area. These results furthermore showed that a yeast biofilm was formed on the fruit which probably helps to improve water retention inside the fruit. “
“Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) using ribosomal subunit proteins coded in the S10–spc-alpha operon as biomarkers was applied for the classification of the Sphingomonadaceae from the environment. To construct a ribosomal protein database, S10-spc-alpha operon of type strains Adenosine of the Sphingomonadaceae and their related alkylphenol polyethoxylate (APEOn)-degrading bacteria were sequenced using specific primers designed based on nucleotide sequences of genome-sequenced strains. The observed MALDI mass spectra of intact cells were compared with the theoretical mass of the constructed ribosomal protein database. The nine selected biomarkers coded in the S10-spc-alpha operon, L18, L22, L24, L29, L30, S08, S14, S17, and S19, could successfully distinguish the Sphingopyxis terrae NBRC 15098T and APEOn-degrading bacteria strain BSN20, despite only one base difference in the 16S rRNA gene sequence.

coli strain was

coli strain was Ibrutinib order created in which the chromosomal copy of cusS was disrupted (Table 1). As the Cus system is the primary copper response system in the absence of oxygen (Outten et al., 2001), the sensitivity of these cells to different concentrations of copper was tested in the absence of oxygen. Disruption

of cusS led to an increase in the toxicity of copper in the strain E. coli ΔcusS (Fig. 2). Upon exposure to copper concentrations above 10 μM, E. coli ΔcusS showed a significant inhibition of growth as observed by the cell density measurements. No growth was seen in the ΔcusS strain above 50 μM CuSO4. However, resistance could be restored through the addition of cusS on the pBADcusS plasmid which has cusS under the control of the arabinose promoter (Fig. 2). No significant differences in growth were seen between the strain

ΔcusS/pBADcusS and the wild-type strain up to 100 μM CuSO4. selleck chemical To address the role of CusS in silver tolerance, E. coli ΔcusS and E. coli ΔcusS/pBADcusS (Table 1) were tested for sensitivity to media containing Ag(I). The MIC of Ag(I) for E. coli strains containing the cusS gene either on the genome (wild type) or on a plasmid (pBADcusS) was 50 μM (Fig. 3 and Table 2). In comparison, the disruption of the cusS gene had a potent effect on Ag(I) sensitivity, where the strain E. coli ΔcusS showed Ag(I) sensitivity at 10 μM metal concentrations. The above data establish that the gene encoding the histidine kinase CusS responds to elevated levels of copper and silver in E. coli. Mutants that lack the cusS gene have higher susceptibility to silver compared to the wild-type or cusS-complemented strain of E. coli. The cusS gene is also required for anaerobic copper resistance as indicated by slower growth of E. coli ΔcusS cells in medium containing copper. Previous work has shown that E. coli and yeast cells undergo increased copper accumulation

under anaerobic conditions (Strain & Culotta, 1996; Weissman et al., 2000; Outten et al., 2001). If the role of CusS is to activate the cus efflux genes under elevated copper concentrations, in the absence of CusS, no expression from the cusCFBA genes would occur, and therefore, no efflux of copper is expected from the cells. To test this hypothesis, the levels of copper were Nintedanib (BIBF 1120) examined in wild-type E. coli, E. coli ΔcusS, and E. coli ΔcusS/pBADcusS by growing the cells anaerobically in copper-containing medium and determining copper content by ICP-MS. Escherichia coli ΔcusS, which lacks the cusS gene, showed a steady increase in copper accumulation with a fourfold increase in copper concentration as compared to the wild-type strain after four hours. Supplying cusS on a plasmid rescued this phenotype, as the copper concentration in E. coli ΔcusS/pBADcusS was similar to that of wild-type E. coli. The copper concentrations in E. coli ΔcusS/pBADcusS reached about 76 ng/108 cells after 2 h and decreased to 60 ng/108 cells after 4 h (Fig. 4).


The MG-132 mw genomes of all three S. aureus strains studied contained two loci belonging to the relBE gene family and one

locus belonging to the mazEF gene family, which was later demonstrated to be a functional TA module in S. aureus (Fu et al., 2007). The toxin, MazFSa, is a sequence-specific endoribonuclease that inhibits cell growth when expressed in both E. coli and S. aureus (Fu et al., 2009; Zhu et al., 2009). The MazEFSa system is cotranscribed with the alternative transcription factor σB under certain stress conditions (Donegan & Cheung, 2009). Additionally, the bioinformatics survey identified three TA loci on Pseudomonas aeruginosa (PA) strain PAO1, relBE, parDE, and higBA (Pandey & Gerdes, 2005). PD0332991 concentration Although no additional work has been published on these TA systems, functional homologs have been described in other pathogenic bacteria, including

RelBE in Streptococcus pneumoniae (Nieto et al., 2006), Yersinia pestis (Goulard et al., 2010) and Mycobacterium tuberculosis (Yang et al., 2010); ParDE in Vibrio cholerae (Yuan et al., 2011); and HigBA in V. cholerae (Christensen-Dalsgaard & Gerdes, 2006; Budde et al., 2007), Proteus vulgaris (Hurley & Woychik, 2009), and Y. pestis (Goulard et al., 2010). While the analysis of sequenced genomes has been informative, there are no data on the prevalence and identity of TA loci in a large cadre of methicillin-resistant S. aureus Venetoclax supplier (MRSA) and PA clinical isolates.

In the current study, we find that mazEF, relBE, higBA, and parDE are widespread in collections of MRSA and PA clinical isolates. Clinical isolates of MRSA were obtained from three medical centers and the Network on Antimicrobial Resistance in S. aureus (NARSA) for a total of 78 strains. The medical centers were Carle Foundation Hospital (Urbana, IL), Memorial Medical Center (Springfield, IL), and Delnor Community Hospital (Geneva, IL). The clinical isolates of PA designated CI01–CI20 were obtained from the sputum of 20 different cystic fibrosis patients at Carle Foundation Hospital, as described previously (Musk et al., 2005). The remaining 22 PA clinical isolates were a kind gift from Cubist Pharmaceuticals Inc. (Lexington, MA) and had been obtained from various acute infections over eight geographically diverse clinical sites in the United States. To assess the clonality of the clinical MRSA and PA isolates, basic molecular typing was performed by PCR-based MLVA described previously (Sabat et al., 2003; Vu-Thien et al., 2007). For MRSA, a minor modification was made to the reported protocol, in that a greater amount of Taq polymerase was added to the PCR mix (5 U) and 6 μL of PCR products were analyzed in 1.8% Low-Range Ultra agarose (Biorad) for 3 h at 6.5 V cm−1.

Of note, the audit did not account for observer bias from patient

Of note, the audit did not account for observer bias from patients completing the questionnaires as part of Hawthorne Effect. Results show a clear inclination towards self-medicating, however majority of patients were frustrated at being unable to freely access their Insulin prior to meals, and being dependent on scheduled

medication ward rounds before receiving their Insulin dose. There is debate as to whether delayed insulin administration has an adverse effect on a patient’s health. All health-professionals that prescribe, handle or administer insulin must now complete a mandatory NHS Diabetes E-learning module on the safe use of Insulin. Further research would be required to prove its effectiveness and positive impact on patient outcomes. 1. Lamont T, Cousins D, Hillson R, Bischler A, Terblanche click here M. Safer Administration of insulin: summary of a safety report

form the Atezolizumab National Patient Safety Agency.?TBMJ 2010;341:c5269 M. Boyda, D. Jonesa, K. Solankia, S. Rakhejaa, C. Tonga, G. Tomlinsonb, K. O’Kellyc, R. Abeyratnec, T. Masudc aDivision for Social Research in Medicines and Health, The School of Pharmacy, University of Nottingham, Nottingham, UK, bClinical Quality, Risk & Safety Team, Nottingham University Hospitals NHS Trust, Nottingham, UK, cHealth Care of Older Persons Directorate, Nottingham University Hospitals NHS Trust, Nottingham, UK The STOPP/START criteria are a useful tool in identifying inappropriate prescribing or prescribing omissions in patients over 65. Retrospective analysis of patient notes was used to identify STOPP/START violations in patients Megestrol Acetate discharged from the Health Care of Older Persons (HCOP) directorate. Secondary care clinicians reduce inappropriate prescribing between admission and discharge.

Prescribing in older patients is challenging due to factors such as multiple morbidities, polypharmacy and changes in pharmacodynamic and pharmacokinetic profiles. Inappropriate prescribing can result in adverse drug reactions, unnecessary hospital admissions and poor outcomes for patients. In 2008, Gallagher et al. published two tools to assist prescribing for older patients: Screening Tool of Older Persons’; Prescriptions (STOPP) and Screening Tool to Alert to Right Treatment (START).1 These tools comprised 65 indicators to identify potentially inappropriate prescriptions and 22 prescribing indicators for potential prescribing omissions respectively. In a previous audit in the same hospital trust conducted in April-August 2012, 105 patients were audited and it was shown that 85% of patients had one or more inappropriate prescriptions on admission and 74% on discharge. As a result of this previous audit, bespoke training on STOPP/START was introduced by the trust.

2 Two of our travelers were repatriated for car accidents during

2 Two of our travelers were repatriated for car accidents during travel. This is consistent with studies of

medical evacuation etiology. Among 504 cases of medical evacuation in Germany, traumas (ie, femoral neck fractures, cerebrocranial trauma, and multiple trauma) were the primary cause of repatriation accounting for 25% of evacuations, followed by cardiovascular diseases (ie, strokes for 14% and myocardial infarctions for 8%).5 Among 115 patients repatriated in the Netherlands from 1998 to 2002, one third of the younger patients GSK2118436 (below 50 years) were evacuated for trauma, whereas in older patients, cardiopulmonary incidents were the most frequent causes of evacuation.6 It should be noted that exacerbation of chronic diseases was an important cause of medical repatriation

among older patients. In addition, the median duration of illness before evacuation of the German patients was 7 days (interquartile range, 4–13 days) putting them at risk of acquiring MDR bacteria when hospitalized during this period of time.5 Infection with MDR bacteria is an emerging and serious worldwide problem. In the past 10 years, many cases of MDR bacteria have been reported in various countries. For example, gram-negative Enterobacteriaceae (Klebsiella pneumoniae and Escherichia coli) with resistance to carbapenem conferred by NDM-1 are known to be widespread Vitamin B12 in India and Pakistan.1 These bacteria may be acquired by travelers and imported into their home country on their return. Indeed, of 1167 Dutch travelers repatriated from Trametinib cell line foreign hospitals to the Netherlands, 18% were diagnosed as carriers of MDR bacteria such as MRSA, vancomycin-resistant enterococci (VRE), and gentamicin-resistant gram-negative bacteria (GGNB).7 The carrier rates of MRSA, VRE, and GGNB were higher than those found in patients hospitalized in Dutch hospitals. In addition to carriers, returning travelers may also be diagnosed with

MDR bacterial infections. This mainly concerns MRSA infections.8 However, as we suggest from these episodes and other recently published studies, MDR gram-negative bacteria are also concerned.1,2 Moreover, this not only refers to repatriated hospitalized travelers but also to patients with community-acquired infections with an associated history of travel. In fact, a Canadian study showed that foreign travel was an important risk factor for developing community-acquired ESBL-producing E coli infections.9 More precisely, overseas travel above all increased the risk of ESBL-producing E coli infections by 5.7 (4.1–7.8), and this risk was higher for travelers to India (OR 145), the Middle East (OR 18), and Africa (OR 7.7). Physicians should be aware of the risk of MDR bacteria carriage among international travelers after hospitalization abroad.

Identification, isolation and cloning for novel genes at a reason

Identification, isolation and cloning for novel genes at a reasonable pace is the main driving force behind the development of unprecedented experimental approaches (Vakhlu et al., 2008). Furthermore, 99.9% of the microbial species represented in any biotope are not culturable at the moment (Streit & Schmitz, 2004; Tringe et al., 2005), which highlights the limitation of any gene discovery protocol dependent on culturing (Vakhlu et al., 2008). Thus, the diversity of enzymes with special fundamental

functions, such as Na+/H+ antiporters that usually require purification from pure culture of a specific organism before analysis, is only partially understood at present. find more Correspondingly, a large fraction of genes in the environment cannot be disclosed due to difficulties in enriching and isolating microorganisms in pure culture. Metagenomics, a culture-independent strategy, provides an access to valuable genetic resources of the microorganisms regardless of whether they can be cultured (Cowan et al., 2005; Guazzaroni et al., 2009). The various target genes have been screened by using a metagenomic library (Schmeisser

et al., 2007). In this study, we applied this methodology for the direct cloning of genes encoding Na+/H+ antiporters from the Dagong Ancient Brine Well by functional Venetoclax cost complementation of antiporter-negative mutant strain. Our results demonstrated that metagenomic DNA libraries Ponatinib are also suitable for direct cloning of functional genes encoding integral membrane proteins from a brine environment. About 10 families of Na+/H+ antiporter genes have been identified in microorganisms in the past, including a single gene of nhaA, nhaB, nhaC, nhaD, nhaG, nhaP, nhaH and chA, and multiple subunits of Mrp antiporter and MnhABCDEFG system (Hunte et al., 2005; Yang et al., 2006). In these genes, only nhaH comes from the halophilic bacteria H. dabanensis D-8T and H. aidingensis AD-6T. Although the gene m-nha cloned in the current study also comes from the halophiles,

to our knowledge it was the first Na+/H+ antiporter gene directly mined by metagenomic technology from the halophiles colonizing a high-salt environment. In single subunit Na+/H+ transporter, it is shown that the negatively charged amino acid residue Asp, localized in the membrane-spanning regions, plays an important role in the binding and transporting of cations such as H+ and Na+ in several antiporter proteins (Majernik et al., 2001). Asp-133, Asp-163 and Asp-164 were proposed to be involved in binding sodium ions in NhaA from E. coli (Inoue et al., 1995). Asp-137 of Nha from H. dabanensis D-8Tand H. aidingensis AD-6T (Yang et al., 2006; Zou et al., 2008), Asp-138 of SynnhaP from Synechocystis sp., and Asp-139 of ApnhaP from A. halophytica were also believed to be necessary for Na+/H+ antiporter activity (Hamada et al., 2001; Waditee et al.