Synthetic peptides were used to generate specific primary antiser

Synthetic peptides were used to generate specific primary antisera against the M. oxyfera NirS (α-NirS) and pMMO (α-pMmoB1) in rabbits. We additionally cloned and heterologously expressed a fragment of pmoB in E. coli and used the expressed fragment to raise antiserum (α-pMmoB2). All antisera were affinity-purified and their specificity was tested on whole-cell extract of the M. oxyfera enrichment culture using SDS-PAGE and immunoblot analysis. Incubations with the antiserum targeting NirS showed a band of approximately the expected size (58.2 kDa; Fig. 2, lane 6). No bands were detected in blots incubated with blocking

buffer or preimmune serum instead of the antiserum (negative controls; data not shown). For the

antisera against pMMO, both α-pMmoB1 and α-pMmoB2 showed a band of about the expected size (44.2 kDa; Fig. 2, lanes Afatinib datasheet 2 and 4), which were absent when incubated with either blocking buffer or preimmune serum instead of the antiserum (negative controls; data not shown). When using the same antisera dilutions, a stronger signal was observed when using α-pMmoB2 compared to α-pMmoB1. These results showed that the derived antisera were specific for the targeted proteins and provide a reliable basis for immunogold localization of the enzymes in ultrathin sections of M. oxyfera cells. Cells from the M. oxyfera enrichment culture were chemically fixed and cryosectioned. Methylomirabilis oxyfera cells could be distinguished from other cells of the community by their polygonal cell shape (Wu et al., FG-4592 mw 2012). The identity of the polygon-shaped cells to M. oxyfera has been confirmed previously by fluorescence in situ hybridization (FISH) using ‘NC10’; Amobarbital bacteria-specific probes (Wu et al., 2012). As in our previous study, the polygon-shaped M. oxyfera cells lacked ICM and the configuration of the cytoplasmic membrane was predominantly smooth and devoid of invaginations (Fig. 3). Cells from the other community members were morphologically diverse. The negative control where ultrathin sections of M. oxyfera cells were incubated with PAG5 or PAG10 alone showed no background labelling (data not shown). Likewise,

cross-reactivity of the affinity-purified antisera with other cells was not detected. In the incubations with α-pMmoB1 or α-pMmoB2, only M. oxyfera cells were specifically labelled. The gold particles occurred at or close to the cytoplasmic membrane (Fig. 3). As for immunoblot analysis, more labelling was observed when using α-pMmoB2 compared to α-pMmoB1 when using the same antisera dilutions. Ultrathin cryosections of M. oxyfera cells were incubated with α-NirS for the determination of the intracellular location of this enzyme. Labelling was observed only in the polygon-shaped M. oxyfera cells (Fig. 4). The negative control where ultrathin sections of M. oxyfera cells were incubated with PAG5 or PAG10 alone showed no background labelling (data not shown).

The second library (MAI1-BLS256) was obtained, using Xoo MAI1 as

The second library (MAI1-BLS256) was obtained, using Xoo MAI1 as a ‘tester’ and Xoc BLS256 as a ‘driver’. SSH was performed, using the BD PCR-Select™ Bacterial Genome Subtraction Kit (BD Biosciences Clontech, Mountain View, CA). Briefly, genomic DNAs of the three bacterial strains were isolated

using the Wizard® Genomic DNA Purification Kit according to the manufacturer’s recommendations (Promega Corporation, Madison, WI). The genomic DNAs were separately digested with RsaI restriction endonuclease (New England this website Biolabs® Inc., Beverly, MA). The DNA subtracted from each library was directly inserted by TA cloning, using the pGEM®-T Easy Vector System (Promega Corporation), and transformed into chemically competent cells (TurboCells® Competent E. coli), as described by the manufacturer (Genlantis Inc., San Diego, CA). We randomly selected

2112 and 2304 individual colonies for the MAI1-PXO86 and MAI1-BLS256 SSH libraries, respectively. Plasmid DNA of subtracted library colonies was obtained from individual clones, using the alkaline lysis procedure according to R.E.A.L. Prep 96 protocols (Qiagen, S.A., Courtaboeuf, France). Insert sequences in the subtracted libraries were one-end sequenced with the T7 primer. We used the computational sequence analysis pipeline created by (Lopez et al., 2004) for cleaning raw sequences, contig construction, and sequence analysis, allowing automatic treatment of our data. This pipeline manages treatment Selleckchem Alectinib of the sequence from the raw sequence (chromatogram) to the creation

of a set of nonredundant the sequences. Bases were called, using the phred program (Ewing et al., 1998). End sequences were trimmed for low quality, and vector sequences were eliminated. Only sequences longer than 100 bp after this trimming process were included in the dataset. The stackpack™ software (Miller et al., 1999) was used to create a set of nonredundant sequences. In a first step, the stackpack™ program creates clusters of sequences having >96% identity over a window of 150 bases. In a second step, sequences from a cluster are assembled using the phrap program. The SSH Xoo MAI1 nonredundant set of sequences was deposited at GenBank’s GSS database ( under accession numbers FI978060–FI978198. Sequences were searched against the NCBI database with blastn ( blast searches were performed against the complete nonredundant database and the genomes of Xoo strains KACC10331, MAFF311018, and PXO99A; Xoc strain BLS256; Xanthomonas campestris pv. campestris (Xcc) strain ATCC 33913; Xanthomonas axonopodis pv. vesicatoria (Xav) strain 85-10; and X. axonopodis pv. citri (Xac) strain 306 using the default parameters.

To avoid artifacts, peak-to-peak differences of more than 35 pT/

To avoid artifacts, peak-to-peak differences of more than 3.5 pT/cm resulted in the rejection of an epoch. After artifact rejection, on average more than 90 valid trials Selleckchem Quizartinib per session remained for event-related averaging. As the amplitude of MEG waveforms was strongly dependent on the individual’s head size and the head position in the MEG device, we did not use the sensor data for analysis. Instead,

we employed distributed source modeling in an empirical Bayesian approach, as implemented in SPM8 (Wellcome Trust Centre for Neuroimaging, University College, London, UK), to reconstruct the cortical sources generating the magnetic-evoked field in response to omission. Subjects’ individual anatomical magnetic resonance images were spatially normalised to a Montreal Neurological Institute (MNI) template brain. The inverse of this

spatial transformation parameter was used to warp a cortical template mesh to the individual magnetic resonance space. The co-registration between MEG sensor positions and the head magnetic resonance imaging was achieved by manually detecting three fiducial points (nasion and the left and right pre-auricular) in the magnetic resonance image that were defined by magnetic resonance markers and the head shape that was measured using a spatial digitiser. To generate the forward model, the lead-field for each sensor was calculated for dipoles at Tanespimycin in vivo each point in the canonical cortical mesh (8196 vertices) by using a single shell model and the ‘forwinv’ toolbox, which SPM shares with Fieldtrip (Oostenveld et al., 2011). The model was then inverted using restricted maximum likelihood

and the multiple sparse priors algorithm (Phillips et al., 2005; Mattout et al., 2006; Friston et al., 2008) for each session separately. In each session, in order to reduce inter-individual variances, each subject’s smoothed images were automatically normalised by SPM using the mean of the entire time period. Because we were mainly interested in the cortical distribution of the omission-related response, which was found in the time window of 100–200 ms after the not omission onset in the previous studies (Yabe et al., 1998; Rüsseler et al., 2001; Bendixen et al., 2009; Horváth et al., 2010; Todorovic et al., 2011; Wacongne et al., 2011), the reconstructions were averaged in the time window of 100–200 ms and the mean reconstruction maps were exported as three-dimensional voxel-based images into MNI space. Finally, the images were smoothed using a Gaussian filter with 8 mm full width half maximum and used for group analysis. For the group analysis, general linear model-based statistical analysis using random field theory was conducted using SPM8.

Previously we showed that elective CS was associated with a 93% d

Previously we showed that elective CS was associated with a 93% decreased MTCT risk in 560 women with undetectable viral loads (around half of whom were tested Sirolimus clinical trial with less sensitive assays

than those currently used) [12]. Here, we also described MTCT rates by mode of delivery, reclassified as prophylactic CS and an attempted vaginal delivery to reflect intended delivery. The possibility exists that some conditions potentially favourable for MTCT such as placental abruption, intrauterine growth restriction (IUGR) and infection of the lower genital tract were also included in the ‘started vaginally’ group. However, prophylactic CS may be preferentially performed where there is a perceived high risk of MTCT (i.e. confounding by indication). Our findings suggest a protective effect of elective CS even at low maternal viral loads, but the study was insufficiently powered to enable any conclusions to be drawn about the benefit of intended elective CS or the risk of intended vaginal delivery in women with HIV-RNA load <50 copies/mL, who can achieve MTCT rates below 0.5%, as seen here and elsewhere [1,3,4]. A decision regarding planned mode of delivery is usually made taking into account the instituted ART and the last measured HIV RNA viral load. Emergency CS XL184 solubility dmso can be the result of a woman with a planned elective CS starting labour earlier than the planned date

or the consequence of a complication during a planned vaginal delivery. The effectiveness of elective CS in PMTCT is just one of the factors requiring consideration in decision-making; the potential risks of CS also need consideration as CS, particularly in HIV-infected women, may cause maternal morbidity in the short term [20,21,39] and in subsequent pregnancies [40]. A further factor to consider is that delivery may not take place as planned:

recent studies have shown that between 38% and 55% of women opting for a vaginal delivery have actually delivered by CS, for a variety of reasons [1,22]. Study limitations include the observational nature of the data and lack of direct information on what the planned mode of delivery was. Elective CS will not impact on MCPs where transmission has already occurred in utero, but we did not have sufficient STK38 data on early PCR tests in infected children to explore timing of transmission. In conclusion, we show that implementation of obstetric interventions for PMTCT are influenced by both evidence-based and ‘opinion-based’ medicine. Our data highlight the effectiveness of antenatal HAART in PMTCT, which has resulted in a very small number of infections in recent years and has contributed to a declining elective CS rate overall. The numbers needed to treat (i.e. the number of elective CS deliveries) to prevent a single transmission will be high taking into account the results of the present and other studies [1,3,4].

After an overnight incubation, zoospores and cysts were collected

After an overnight incubation, zoospores and cysts were collected. Germinating cysts were collected after vortexing the zoospore/cyst suspension and incubation at 24 °C for 4–5 h. The RTG-2 cell line is a continuous cell line obtained from ATCC (ATCC CCL-55). It was derived from rainbow trout (Oncorhynchus mykiss) gonadal tissue (Wolf & Quimby, 1962) and was maintained at 24 °C in 75-cm2 cell culture flasks (Nunc) in 25 mL Leibovitz’s L-15 medium (Gibco) supplemented with 10% foetal bovine serum (BioSera), 200 U mL−1 penicillin and

200 μg mL−1 streptomycin (Fisher). Flasks with confluent cell growth were inoculated weekly after splitting cells by washing three times with Hank’s balanced salt solution (Gibco) at room temperature and treating the cells with 5 mL 0.5 g L−1 trypsin–EDTA (Invitrogen) until the cells were detached from the flasks. A fresh medium Pembrolizumab mouse was added, and after gentle shaking, the cells were distributed into three to five flasks, each containing approximately 30 mL of cell suspension, or 2–4 mL was added to each well of six-well plates Raf targets (Nunc), where the wells contained an autoclaved glass coverslip. RNA was isolated from the preinfection stages of S. parasitica strain CBS223.65, including zoospores, cysts and germinating cysts, at Vertis Biotechnology AG (Germany), using a Trizol-based extraction. From total RNA, polyA+ was prepared and cDNA was synthesized according to the Vertis Biotechnology

Anacetrapib AG standard protocol for full-length enriched cDNA using an oligo(dT)-NotI primer for first-strand synthesis. Before cloning, the cDNA was amplified with 13 cycles of PCR. For directional cloning, cDNA was subjected to a limited exonuclease treatment to generate EcoRI overhangs at the 5′ end, and was subsequently digested with NotI. Size-fractioned cDNA fractions >0.5 kb were ligated into EcoRI and NotI digested pcDNA3.1 (Invitrogen) and subsequently transformed via electroporation into T1 phage-resistant TransforMax™ EC100™-T1R electrocompetent cells (Epicentre Biotechnologies). The transformants were stored in 15% v/v glycerol at −80 °C. End-sequencing was performed on plasmid

DNA isolated from 1000 clones of the cDNA library by a single pass sequence from the 5′ end with a primer specific for the pcDNA3.1 vector by GATC Biotech (Cambridge, UK) using an ABI3730 system. The EST sequences were trimmed to remove vector sequence and validated using seqclean (, and subsequently, contigs were assembled using cap3 ( Screening for secreted proteins was performed by signalp ( analysis using both hidden markov models and neural networks programs, and subsequently, the sequences were screened by word searches for the presence of an RxLR motif. blastp analyses were performed at the NCBI website (http://blast.ncbi.nlm.

We sincerely thank Mr T Sugita for his kind gifts of paddy rice

We sincerely thank Mr. T. Sugita for his kind gifts of paddy rice. This study was partly supported by a Grant-in-Aid for Young Scientists (Start-up) (No. 21880053) from the Japan Society for the Promotion of Science, and a research grant for production of valuable livestock by feeding self-sufficient forage crops from the Ministry of Agriculture, Forestry

and Fisheries of Japan. “
“Nattokinase (subtilisin NAT, NK) is a relatively effective microbial fibrinolytic enzyme that has been identified and characterized from Bacillus natto. In the current report, DNA family shuffling was used to improve the fibrinolytic activity of nattokinase. Three homologous genes from B. nattoAS 1.107, Bacillus amyloliquefaciensCICC 20164 and Bacillus licheniformisCICC 10092 were shuffled to generate a mutant library. A plate-based method was used to screen the mutant libraries Doxorubicin for improved activity. After three rounds of DNA shuffling, one

desirable mutant with 16 amino acid substitutions was obtained. The mutant enzyme was purified and Bioactive Compound Library characterized. The kinetic measurements showed that the catalytic efficiency of the mutant NK was approximately 2.3 times higher than that of the wild-type nattokinase. In addition, the molecular modeling analysis suggested that the mutations affect the enzymatic function by changing the surface conformation of the substrate-binding pocket. The current study shows that the evolution of nattokinase with improved fibrinolytic activity by DNA family shuffling is feasible and provides useful references Dichloromethane dehalogenase to facilitate the application of nattokinase in thrombolytic therapy. Thrombotic diseases, especially acute myocardial infarction, imperil the human lives and health in modern life. Compared with widely used thrombolytic agents, such as tissue plasminogen activator (t-PA) and urokinase (Mukhametova et al.,

2002), several cheaper and safer resources have been extensively investigated over the years (Nakanishi et al., 1994; Moriyama & Takaoka, 2006). Among them, nattokinase (NK), which was extracted from a traditional Japanese fermented natto, has attracted interest. The molecular mass and isoelectric point of NK are about 28 kD and 8.6 respectively. NK has sufficient stability of pH and temperature to be stable in the gastrointestinal tract (Sumi et al., 1987). NK directly cleaves cross-linked fibrin in vitro, catalyzes the conversion of plasminogen to plasmin or inactivates the fibrinolysis inhibitor (PAI-1) (Fujita et al., 1993; Urano et al., 2001). Until recently, most studies of NK have focused on its thrombolytic mechanism, effects, heterologous expression and purification. In vitro molecular-directed evolution is a new strategy that has been used to change the characteristics of enzymes in recent years. The complete nucleotide sequence of the subtilisin NAT aprN has been obtained using shotgun cloning, and the amino acid sequence has been deduced from the DNA sequence (Nakamura et al.

The growth curve of S aureus ATCC 29213 is shown in Fig 1 We f

The growth curve of S. aureus ATCC 29213 is shown in Fig. 1. We found that 1/16 × MIC, 1/8 × MIC, and 1/4 × MIC of licochalcone A had no obvious XL184 research buy effects on the growth of S. aureus. Although S. aureus grew in the presence of 1/2 × MIC of licochalcone A, the growth velocity was much slower, and after 30 min, the OD value was only 51.5% of that of the control culture. However, after 360 min of licochalcone A treatment, there was no significant difference in the OD value among all the cultures. The secretion of two major enterotoxins (SEA and SEB) by S. aureus, when exposed to subinhibitory concentrations of licochalcone A, was analysed in the study; both MSSA ATCC 29213 and MRSA strain 2985 were investigated. As shown

in Fig. 2, the addition of licochalcone A reduced the secretion of SEA and SEB in a dose-dependent manner. Growth in the presence of 1/16 × MIC licochalcone A led to a measurable reduction

in SEA and SEB secretion; at 1/2 × MIC, no immunoreactive protein could be detected in cultures of ATCC 29213 and MRSA 2985. The proteolytic activity of the cultures was determined to confirm whether the reduction of SEA and SEB secretion by S. aureus was due to an increase in protease secretion induced by licochalcone A. There was no significant effect on protease secretion by ATCC 29213 or MRSA 2985 cultured with 1/2 × MIC of licochalcone A (data not shown). It is well known that among the proteins released, enterotoxins are the most important exotoxins secreted by S. aureus that could act as superantigens, stimulating T cells to release proinflammatory cytokines and stimulating T-cell proliferation selleck chemicals (Balaban & Rasooly, 2000). Therefore, in this study, a TNF release assay and a murine T-cell proliferation assay were performed to clarify the biological relevance of the reduction in SEA and SEB secretion caused by licochalcone A. As expected, the culture supernatants of S. aureus grown in the presence of graded subinhibitory concentrations of licochalcone A elicited much lower TNF-α production by spleen cells (Fig. 3) and stimulated a significantly lower level of T-cell

proliferation (Fig. 4). In addition, licochalcone A itself did not induce TNF release or stimulate T-cell activation at 1 × MIC or 2 × MIC concentrations. Apparently, licochalcone A reduced the TNF-inducing and T-cell-activating activities in a Sclareol dose-dependent manner. Real-time RT-PCR was performed to evaluate the transcriptional level of sea, seb, and agrA after treatment with subinhibitory concentrations of licochalcone A. As shown in Fig. 5, licochalcone A markedly decreased the transcription of sea, seb, and agrA in S. aureus strains ATCC 29213. When cultured with 1/2 × MIC of licochalcone A, the transcriptional levels of sea, seb, and agrA in strain ATCC 29213 were decreased by 6.2-, 7.6-, and 4.2-fold, respectively. The investigated genes were affected by licochalcone A at the transcriptional level in a dose-dependent manner.

The CW-EPR spectra were recorded on a Bruker Elexsys E500 spectro

The CW-EPR spectra were recorded on a Bruker Elexsys E500 spectrometer, at X-band (9.38 GHz), and 100-kHz modulation. The temperature at 6 K was maintained with an Oxford liquid Helium continuous flow cryostat. The g-values were determined by measuring the magnetic field and the microwave frequency. The UV/Vis difference spectra were recorded at room temperature on a Shimadzu UV-2401 PC spectrophotometer using 1.0-cm light

path cells, Epacadostat mouse as described previously (Gómez-Manzo et al., 2008). Dehydrogenase activities associated with membranes and purified fractions were determined by a colorimetric method using potassium ferricyanide as the electron acceptor according to the standard method described by Matsushita et al. (1995). We previously demonstrated that in N2-fixing cultures of Ga. diazotrophicus with forced aeration and physiological acidification,

the dehydrogenase activities for glucose, ethanol, acetaldehyde, and NADH were maximally expressed (Flores-Encarnación selleck screening library et al., 1999). Accordingly, we show that under the same growth conditions, ADH is largely expressed in its active form (ADHa). Indeed, during the last purification step (Table 1, Fig. 1a), size exclusion chromatography, ADHa elutes as the major cytochrome c containing fraction. A second and comparatively small peak containing cytochrome c eluted at longer elution times. This latter peak was poorly active on ethanol, and therefore, it was named inactive ADH (ADHi). The good resolution of the two proteins indicates that there are significant

differences in their respective molecular sizes; indeed, size calibration of the column chromatography suggested that ADHa is almost threefold (330 kDa) the size showed by ADHi (120 kDa); thus, it seems that purified ADHa is an oligomeric association of three heterodimers, and therefore, the inactive ADH complex would be constituted Pregnenolone of a single heterodimer. The purification protocol used (Table 1) yielded a homogeneous ADHi complex with a purification yield of 1.2%, which is several fold lower than the 15% generally obtained during purification of its active counterpart (Gómez-Manzo et al., 2008). However, during longer culture times, the amount of ADHi associated with the membrane increased (not shown), in agreement with reports in G. suboxydans (Matsushita et al., 1995). Native PAGE of the purified ADHi and ADHa complexes (a and b in Fig. 1b, respectively) confirmed the oligomeric difference determined by size exclusion chromatography. Homogeneous protein bands with Mrs = 115 and 345 kDa for ADHi and ADHa, respectively, were obtained. Under denaturing conditions in SDS-PAGE, the purified ADHi and ADHa (c and d, in Fig. 2, respectively) were dissociated into two bands with relative molecular masses of 72 and 44 kDa for ADH-SI and ADH-SII, respectively. Thus, the basic heterodimer units of the active and inactive ADH complexes of Ga. diazotrophicus have the same subunit structure.

coelicolor FabH with the acetyl-CoA-specific E coli FabH (YL1/ec

coelicolor FabH with the acetyl-CoA-specific E. coli FabH (YL1/ecFabH mutant) results in a dramatic shift to a fatty acid profile of predominantly straight-chain fatty acids (Li et al., 2005). As predicted, FabH was able to use malonyl-RedQ in place of malonyl-FabC. Under saturating malonyl-RedQ VX-765 order conditions, FabH was able to use either acetyl-CoA or isobutyryl-CoA (Table 1). The Km values for each of these were comparable to those observed using

malonyl-FabC, and again there was almost a 40-fold higher catalytic efficiency (kcat/Km) for isobutyryl-CoA compared to acetyl-CoA. However, for both acyl-CoA substrates, the reaction rate kcat was at least 20-fold less using malonyl-RedQ vs. malonyl-FabC (Fig. 2). At fixed isobutyryl-CoA and acetyl-CoA concentrations and variable malonyl-RedQ or malonyl-FabC IDH inhibitor cancer concentrations, similar sets of observations were made. Greater catalytic efficiency was seen with isobutyryl-CoA relative to acetyl-CoA, and for each acyl-CoA substrate, the apparent reaction rate was much faster using malonyl-FabC than with malonyl-RedQ.

This set of analyses also demonstrated that the apparent Km for malonyl-FabC (4.53 μM) and malonyl-RedQ (7.80 μM) was comparable. Thus, the difference in overall catalytic efficiency of FabH using malonyl-ACP substrates arises predominantly from differences in apparent catalytic rates rather than Km values. The ability of FabH to utilize malonyl-RedQ and to have a preference for isobutyryl-CoA Thalidomide is consistent with a) genetic data which suggest that FabH can initiate prodiginine biosynthesis in SJM1, the S. coelicolor redP deletion mutant, and b) the observation of a significant

increase in branched-chain alkyl prodiginines in the SJM1 mutant relative to the wild-type S. coelicolor (Mo et al., 2005). A final observation from these analyses is that the maximal kinetic efficiency of FabH (kcat/Km of 9.84 μM−1 min−1 using isobutyryl-CoA and malonyl-FabC) is 66-fold higher than that of RedP (kcat/Km of 0.147 μM−1 min−1 using acetyl-CoA and malonyl-RedQ). This difference might arise from the ability of FabH to utilize isobutyryl-CoA (the enzymes have comparable efficiencies using acetyl-CoA), or because FabH is a primary metabolic enzyme. Initial characterization of many FabH enzymes, including those from streptomycetes, was carried out with a commercially available E. coli ACP (Han et al., 1998; Choi et al., 2000a, b; Khandekar et al., 2001). Subsequent work has revealed that these enzymes have ACP specificity. Improved catalytic activity and in some cases apparent changes in acyl group specificity can be observed when assays are performed using malonyl-ACP generated from the cognate ACP (Florova et al., 2002; Brown et al., 2005).

Secondly, random amplification of polymorphic DNA (RAPD) amplific

Secondly, random amplification of polymorphic DNA (RAPD) amplifications or SmaI digestion Selleckchem LDK378 allowed us to differentiate (1) A. flavus, A. oryzae and A. minisclerotigenes; (2) A. parasiticus, A. sojae and A. arachidicola; (3) A. tamarii, A. bombycis and A. pseudotamarii. Among the 11 species, only A. parvisclerotigenus cannot be differentiated from A. flavus. Using the results of real-time PCR, RAPD and SmaI digestion, a decision-making tree was drawn up to identify nine of the 11 species of section Flavi. In contrast to

conventional morphological methods, which are often time-consuming, the molecular strategy proposed here is based mainly on real-time PCR, which is rapid and requires minimal handling. Aspergillus section Flavi includes six economically important species that are very closely related morphologically and phylogenetically, and which are often separated into two groups Compound Library solubility dmso on the basis of their impact on food or human health. The first group includes Aspergillus flavus, Aspergillus parasiticus and Aspergillus nomius, which can cause serious damage to stored food products such as wheat and rye grain, nuts, spices and peanuts (Kurtzman et al.,

1987; Moody & Tyler, 1990a; Samson et al., 2000; Rigo et al., 2002; Hedayati et al., 2007). Furthermore, these species can produce carcinogenic secondary metabolites, the aflatoxins (Klich & Mullaney, 1987; Kurtzman et al., 1987; Yuan et al., 1995; Samson et al., 2000; Hedayati et al., 2007). After Aspergillus fumigatus, A. flavus is known as the second cause of human invasive aspergillosis (Denning, 1998; Latgé, 1999; Hedayati et al., 2007). Often, the name A. flavus is mistakenly used to describe the different species of Aspergillus section Flavi. Other recently described species are included in this group but these species are less important economically or rarely isolated. Indeed,

Aspergillus bombycis was described by Peterson et al. (2001) from nine isolates collected in silkworm-rearing houses. A variety of A. flavus, A. flavus var. parvisclerotigenus, has been raised to species level by Frisvad et al. (2005) as Aspergillus parvisclerotigenus. Aspergillus arachidicola Rho and Aspergillus minisclerotigenes were described by Pildain et al. (2008). Seven strains of A. arachidicola were isolated in Argentina from Arachis. Some of the 15 strains of A. minisclerotigenes were been described for a long time as A. flavus group II by Geiser et al. (1998a, b, 2000), before being raised to the species rank by Pildain et al. (2008). Hence, many authors have shown evidence that A. flavus sensu lato may consist of several species (Geiser et al., 1998a, b, 2000; Pildain et al, 2008). The second group of the section Flavi comprises the nonproducing aflatoxin species Aspergillus tamarii, Aspergillus oryzae and Aspergillus sojae. The last two have lost the ability to produce aflatoxins (Samson et al., 2000) and are widely used as a koji mold for the production of fermented foods in some Asian countries.