Sequence analysis of the grey mouse lemur (<Emphasis Type="Italic">Microcebus murinus</Emphasis>) <Emphasis Type="Italic">MHC class II DQ</Emphasis> and <Emphasis Type="Italic">DR</Emphasis> region

We here report the genomic organisation of the grey mouse lemur (Microcebus murinus) MHC class II DQ and DR region based on BAC clone analysis. The sequenced Mimu-MHC haplotype spans 343 kb and encompasses the genes TAP2, DOB, DQB, DQA, DRB, DRA, BTNL2 and a further BTNL gene. The DQ and DR genes of this haplotype are not duplicated. Mimu-DOB is not transcribed and represents a pseudogene due to deletions and premature stop codons. Analysis of BAC clone DNA, a cDNA sample and eight genomic DNA samples suggests that Mimu-DRB, Mimu-DQA and Mimu-DQB are highly polymorphic with the majority of peptide-binding residues being affected by polymorphisms. In contrast, Mimu-DRA is moderately polymorphic, and the variable amino acid positions are not part of the peptide-binding region. Phylogenetic analysis of Mimu-DQA and Mimu-DQB and other primate DQA and DQB genes indicates that duplication of DQA and DQB loci occurred in Anthropoidea after the split from Strepsirrhini.     

Detection and discrimination between ochratoxin producer and non-producer strains of <Emphasis Type="Italic">Penicillium nordicum</Emphasis> on a ham-based medium using an electronic nose

The aim of this work was to evaluate the potential use of qualitative volatile patterns produced by Penicillium nordicum to discriminate between ochratoxin A (OTA) producers and non-producer strains on a ham-based medium. Experiments were carried out on a 3% ham medium at two water activities (a_w ; 0.995, 0.95) inoculated with P. nordicum spores and incubated at 25°C for up to 14 days. Growing colonies were sampled after 1, 2, 3, 7 and 14 days, placed in 30-ml vials, sealed and the head space analysed using a hybrid sensor electronic nose device. The effect of environmental conditions on growth and OTA production was evaluated based on the qualitative response. However, after 7 days, it was possible to discriminate between strains grown at 0.995 a_w, and after 14 days, the OTA producer and non-producer strain and the controls could be discriminated at both a_w levels. This study suggests that volatile patterns produced by P. nordicum strains may differ and be used to predict the presence of toxigenic contaminants in ham. This approach could be utilised in ham production as part of a quality assurance system for preventing OTA contamination.     

Potential involvement of more than one locus in trait manifestation for individuals with Leber congenital amaurosis

Leber congenital amaurosis (LCA) is a clinically and genetically heterogeneous retinal dystrophy. The causes of LCA have been unraveled partially at the molecular level. At least 14 genes have been reported that, when mutated, result in LCA. To understand the roles of the known genes in LCA, a group of outbred subjects from 60 apparently either recessive families, with one or more affected individuals, or isolated patients were evaluated. One affected individual from each family underwent comprehensive mutational analysis by direct DNA sequencing of all coding regions and splice junctions of 13 LCA genes. Mutations were identified in 70% of individuals. CEP290 made the largest contribution to the identified mutations, providing 43% of those mutant alleles. We identified seven families in which affected individuals with two mutant alleles, sufficient to cause disease, had an additional mutation at a second LCA locus. Our findings suggest that mutational load can be important to penetrance of the LCA phenotype.     

Diel differences in fish assemblages in nearshore eelgrass and kelp habitats in Prince William Sound,Alaska

The importance of a particular habitat to nearshore fishes can be best assessed by both diurnal and nocturnal sampling. To determine diel differences in fish assemblages in nearshore eelgrass and understory kelp habitats, fishes were sampled diurnally and nocturnally at six locations in western Prince William Sound, Alaska, in summer 2007. Abundance of fish between day and night were similar, but species composition and mean size of some fish changed. Species richness and species diversity were similar in eelgrass during the day and night, whereas in kelp, species richness and species diversity were greater at night than during the day. In eelgrass, saffron cod (Eleginus gracilis) was the most abundant species during the day and night. In kelp, the most abundant species were Pacific herring (Clupea pallasii) during the day and saffron cod at night. Diel differences in fish size varied by species and habitat. Mean length of saffron cod was similar between day and night in eelgrass but was greatest during the day in kelp. Pacific herring were larger at night than during the day in kelp. Diel sampling is important to identity nearshore habitats essential to fish and help manage fish stocks at risk.     

A novel xylanase,XynA4-2, from thermoacidophilic <Emphasis Type="Italic">Alicyclobacillus</Emphasis> sp. A4 with potential applications in the brewing industry

A xylanase gene, xynA4-2, was obtained from the genome sequence of thermoacidophilic Alicyclobacillus sp. A4 and expressed in Escherichia coli BL21 (DE3). xynA4-2 encodes a mature protein of 411 residues with a calculated molecular weight of 46.8 kDa. Based on the amino acid sequence similarities (highest identity of 61%), the enzyme was confined into glycoside hydrolase family 10. The purified recombinant XynA4-2 exhibited maximum activity at pH 6.2 and 55°C. The enzyme was stable over a broad pH range, retaining more than 90% of the original activity at pH 5.8–12.0, 37°C for 1 h. The substrate specificity of XynA4-2 was relatively narrow, exhibiting 100, 93, and 35% of the relative activity towards birchwood xylan, oat spelt xylan, and wheat arabinoxylan, respectively. Supplementation of XynA4-2 to mash caused the reduction of mash filtration rate (5.6%) and viscosity (4.0%). When combined with the commercial glucanase from Sunson, higher reduction was detected in the filtration rate (12.0%) and viscosity (17.2%). These favorable properties make XynA4-2 a good candidate in the brewing industry.     

The Effect of Ultrasonificated Extracts of <Emphasis Type="Italic">Spirulina maxima</Emphasis> on the Anticancer Activity

The effect of ultrasonic extraction on extraction yields, cytotoxicity, and anticancer activity of Spirulina maxima was investigated in this study. Optimal extraction conditions were determined as 60 kHz frequency at 60°C for 30 min with 120 W intensity, which resulted in 19.3% of extraction yields and 19.1% of cytotoxicity on normal human cells. Yields from conventional water and ethanol extraction were 15.8% at 100°C and 8.3% at 80°C, respectively. It was found that the extracts obtained by ultrasonic extraction process selectively inhibited the digestive-related cancer cell lines, such as human stomach cancer cells, having 89% of the highest inhibition ratio and 4.5 of the highest selectivity. In adding 0.5 mg/mL of the extract, human promyelocytic leukemia cells' cell differentiation was increased 1.72 times over that of the control. Expression level of B cell lymphoma-2 from Hep3B cell was also effectively suppressed by the extract obtained at 60 kHz and 60°C, leading to the inhibition of the early step of carcinogenesis. This work suggests that anticancer activity of the extracts is due to water-soluble polysaccharides rather than proteins and is further supported by the result that the ultrasonification extraction process can efficiently extract relatively intact polysaccharides rather than digesting the proteins in S. maxima by matrix assisted laser desorption ionization-time of flight and high performance size exclusion chromatography chromatogram analyses. Therefore, ultrasonic extraction increases both extraction yield and the biological activity of S. maxima extracts, which might be useful as an alternative natural anticancer agent in the medical and food industries.     

High throughput MLVA-16 typing for <Emphasis Type="Italic">Brucella</Emphasis> based on the microfluidics technology

Background  

Brucellosis, a zoonosis caused by the genus Brucella, has been eradicated in Northern Europe, Australia, the USA and Canada, but remains endemic in most areas of the world. The strain and biovar typing of Brucella field samples isolated in outbreaks is useful for tracing back source of infection and may be crucial for discriminating naturally occurring outbreaks versus bioterrorist events, being Brucella a potential biological warfare agent. In the last years MLVA-16 has been described for Brucella spp. genotyping. The MLVA band profiles may be resolved by different techniques i.e. the manual agarose gels, the capillary electrophoresis sequencing systems or the microfluidic Lab-on-Chip electrophoresis. In this paper we described a high throughput system of MLVA-16 typing for Brucella spp. by using of the microfluidics technology.     

Antistaphylococcal and biofilm inhibitory activities of acetyl-11-keto-β-boswellic acid from <Emphasis Type="Italic">Boswellia serrata</Emphasis>

Background  

Boswellic acids are pentacyclic triterpenes, which are produced in plants belonging to the genus Boswellia. Boswellic acids appear in the resin exudates of the plant and it makes up 25-35% of the resin. β-boswellic acid, 11-keto-β-boswellic acid and acetyl-11-keto-β-boswellic acid have been implicated in apoptosis of cancer cells, particularly that of brain tumors and cells affected by leukemia or colon cancer. These molecules are also associated with potent antimicrobial activities. The present study describes the antimicrobial activities of boswellic acid molecules against 112 pathogenic bacterial isolates including ATCC strains. Acetyl-11-keto-β-boswellic acid (AKBA), which exhibited the most potent antibacterial activity, was further evaluated in time kill studies, postantibiotic effect (PAE) and biofilm susceptibility assay. The mechanism of action of AKBA was investigated by propidium iodide uptake, leakage of 260 and 280 nm absorbing material assays.     

An alternative excited-state proton transfer pathway in green fluorescent protein variant S205V

Wild-type green fluorescent protein (wt-GFP) has a prominent absorbance band centered at approximately 395 nm, attributed to the neutral chromophore form. The green emission arising upon excitation of this band results from excited-state proton transfer (ESPT) from the chromophore hydroxyl, through a hydrogen-bond network proposed to consist of a water molecule and Ser205, to Glu222. Although evidence for Glu222 as a terminal proton acceptor has already been obtained, no evidence for the participation of Ser205 in the proton transfer process exists. To examine the role of Ser205 in the proton transfer, we mutated Ser205 to valine. However, the derived GFP variant S205V, upon excitation at 400 nm, still produces green fluorescence. Time-resolved emission spectroscopy suggests that ESPT contributes to the green fluorescence, and that the proton transfer takes place approximately 30 times more slowly than in wt-GFP. The crystal structure of S205V reveals rearrangement of Glu222 and Thr203, forming a new hydrogen-bonding network. We propose this network to be an alternative ESPT pathway with distinctive features that explain the significantly slowed rate of proton transfer. In support of this proposal, the double mutant S205V/T203V is shown to be a novel blue fluorescent protein containing a tyrosine-based chromophore, yet is incapable of ESPT. The results have implications for the detailed mechanism of ESPT and the photocycle of wt-GFP, in particular for the structures of spectroscopically identified intermediates in the cycle.