<Emphasis Type=Italic>In vitro</Emphasis> organogenesis of <Emphasis Type=Italic>Passiflora alata</Emphasis>

Passiflora alata in vitro organogenesis was studied based on explant type, culture medium composition, and incubation conditions. The results indicated that the morphogenic process occurred more efficiently when hypocotyl segment-derived explants were cultured in media supplemented with cytokinin and AgNO₃ incubated under a 16-h photoperiod. The shoot bud elongation and plant development were obtained by transferring the material to MSM culture medium supplemented with GA₃ and incubated in flasks with vented lids. Histological analyses of the process revealed that the difficulties in obtaining plants could be related to the development of protuberances and leaf primordia structures, which did not contain shoot apical meristem. Roots developed easily by transferring elongated shoots to 1/2 MSM culture medium. Plant acclimatization occurred successfully, and somaclonal variation was not visually detected. The efficiency of this organogenesis protocol will be evaluated for genetic transformation of this species to obtain transgenic plants expressing genes that can influence the resistance to Cowpea aphid borne mosaic virus.     

<Emphasis Type=Italic>Pseudomonas aeruginosa</Emphasis> inhibits <Emphasis Type=Italic>in-vitro Candida</Emphasis> biofilm development

Background  

Elucidation of the communal behavior of microbes in mixed species biofilms may have a major impact on understanding infectious diseases and for the therapeutics. Although, the structure and the properties of monospecies biofilms and their role in disease have been extensively studied during the last decade, the interactions within mixed biofilms consisting of bacteria and fungi such as Candida spp. have not been illustrated in depth. Hence, the aim of this study was to evaluate the interspecies interactions of Pseudomonas aeruginosa and six different species of Candida comprising C. albicans, C. glabrata, C. krusei, C. tropicalis, C. parapsilosis, and C. dubliniensis in dual species biofilm development.     

Efficient separation and purification of allophycocyanin from <Emphasis Type=Italic>Spirulina</Emphasis> (<Emphasis Type=Italic>Arthrospira</Emphasis>) <Emphasis Type=Italic>platensis</Emphasis>

Allophycocyanin (APC) is a minor component of phycobiliproteins in cyanobacteria and red algae. This paper describes a simple and inexpensive extracting method for isolating APC from Spirulina (Arthrospira) platensis with high efficiency. The crude phycobiliprotein extract was pretreated by ammonium sulfate fractionation. Then, by adding hydroxylapatite into crude phycobiliprotein extract dissolved in 20 mM phosphate buffer (pH 7.0), APC was selectively adsorbed by hydroxylapatite but C-phycocyanin (C-PC) was not. The hydroxylapatite was collected and APC was extracted from the crude phycobiliprotein extract. Then, the enriched APC was washed off from the hydroxylapatite using 100 mM phosphate buffer (pH 7.0). In this simple extracting method it was easy to remove C-PC and isolate APC in large amounts. The absorbance ratio A ₆₅₀/A ₂₈₀ of extracted APC reached 2.0. The recovery yield was 70%, representing 4.61 mg · g⁻¹ wet weight. The extracted APC could be further purified by a simple anion-exchange chromatography with a pH gradient from 5.6 to 4.0. The absorbance ratio A ₆₅₀/A ₂₈₀ of the purified APC reached 5.0, and the overall recovery yield was 43%, representing 2.83 mg · g⁻¹ wet weight. Its purity was confirmed by native polyacrylamide gel electrophoresis (PAGE) and sodium dodecyl sulfate-PAGE.     

Attenuation of fibrosis <Emphasis Type=Italic>in vitro</Emphasis> and <Emphasis Type=Italic>in vivo</Emphasis> with <Emphasis Type=Italic>SPARC</Emphasis> siRNA

Introduction  

SPARC is a matricellular protein, which, along with other extracellular matrix components including collagens, is commonly over-expressed in fibrotic diseases. The purpose of this study was to examine whether inhibition of SPARC can regulate collagen expression in vitro and in vivo, and subsequently attenuate fibrotic stimulation by bleomycin in mouse skin and lungs.     

Interaction of <Emphasis Type=Italic>Bdellovibrio bacteriovorus</Emphasis> with bacteria <Emphasis Type=Italic>Campylobacter jejuni</Emphasis> and <Emphasis Type=Italic>Helicobacter pylori</Emphasis>

Interaction of Bdellovibrio bacteriovorus 100NCJB with bacteria Campylobacter jejuni (strains 1, 2, 3, 4, and 5) and Helicobacter pylori, strain TX30a, was confirmed. The results indicate that lytic activity of bdellovibrios both in liquid media and cells attached to a surface was observed. The potential use of the antimicrobial activity of predatory bacteria for environmental bioprotection and public health is discussed.     

High-Level Expression of Heme-Dependent Catalase Gene <Emphasis Type=Italic>katA</Emphasis> from <Emphasis Type=Italic>Lactobacillus Sakei</Emphasis> Protects <Emphasis Type=Italic>Lactobacillus Rhamnosus</Emphasis> from Oxidative Stress

Lactic acid bacteria (LAB) are generally sensitive to hydrogen peroxide (H₂O₂), Lactobacillus sakei YSI8 is one of the very few LAB strains able to degrade H₂O₂ through the action of a heme-dependent catalase. Lactobacillus rhamnosus strains are very important probiotic starter cultures in meat product fermentation, but they are deficient in catalase. In this study, the effect of heterologous expression of L. sakei catalase gene katA in L. rhamnosus on its oxidative stress resistance was tested. The recombinant L. rhamnosus AS 1.2466 was able to decompose H₂O₂ and the catalase activity reached 2.85 μmol H₂O₂/min/10⁸ c.f.u. Furthermore, the expression of the katA gene in L. rhamnosus conferred enhanced oxidative resistance on the host. The survival ratios after short-term H₂O₂ challenge were increased 600 and 10⁴-fold at exponential and stationary phase, respectively. Further, viable cells were 100-fold higher in long-term aerated cultures. Simulation experiment demonstrated that both growth and catalase activity of recombinant L. rhamnosus displayed high stability under environmental conditions similar to those encountered during sausage fermentation.     

Comparative analysis of <Emphasis Type=Italic>iol</Emphasis> clusters in <Emphasis Type=Italic>Lactobacillus casei</Emphasis> strains

The present study was designed to expand genetic knowledge of myo -inositol (MI) metabolism in Lactobacillus casei. Twenty-four L. casei isolates of dairy origin were tested for the presence of iol cluster. PCR screening revealed eight strains encoded functions involved in MI utilization, of which one strain was able to use MI as carbon source. To gain a deeper understanding of the function of iol genes, four of the eight observed iol clusters were subjected to the full sequencing procedure. The results showed that the iol cluster was not a common feature among dairy L. casei strains. In addition, the four iol clusters were highly similar to one another in terms of sequence similarity and operon architecture. However, abundant polymorphisms that comprised a majority of synonymous mutations were detected throughout the full sequences. Three of them distributed among iolB, iolC, and iolT genes were found in linkage to MI-negative phenotype. Compared with other bacterial iol clusters, the iol cluster of L. casei showed a high similarity with that of Bacillus subtilis.     

<Emphasis Type=Italic>Boletus kermesinus</Emphasis>, a new species of <Emphasis Type=Italic>Boletus</Emphasis> section <Emphasis Type=Italic>Luridi</Emphasis> from central Honshu,Japan

Boletus kermesinus, a new species of Boletus section Luridi, is fully described and illustrated based on the materials collected in subalpine coniferous forests of central Honshu, Japan. It has distinctive features of dark-red basidiomata having distinct viscidity in the pileus surface, usually unchanging flesh, discolorous red pores, and an entirely reticulate stipe becoming coarsely lacerate-rimose with age.     

The isolation and analysis of a soybean <Emphasis Type=Italic>CO</Emphasis> Homologue <Emphasis Type=Italic>GmCOL10</Emphasis>

The CONSTANS (CO) gene is a key regulator of the response to photoperiod in the model plant Arabidopsis thaliana, and its homologues are present in many plant species. We describe here the isolation of the CO homologue for zinc finger protein gene GmCOL10 (Glycine max CONSTANS-Like 10) from the soybean cultivar Kennong18. Sequence comparisons showed that the closest A. thaliana gene to GmCOL10 is COL5. The expression of GmCOL10 was regulated in a circadian manner, especially under short-day conditions. The expression of GmCOL10 was concentrated in vegetative organs, and in particular in the unifoliolates and cotyledons. An analysis of subcellular localization found GmCOL10 in the nucleus. Our data suggested that GmCOL10 was not related to the photoperiodic pathway of floral transition as Arabidopsis CO does.