A simple method for extracting C-phycocyanin from <Emphasis Type="Italic">Spirulina platensis</Emphasis> using <Emphasis Type="Italic">Klebsiella pneumoniae</Emphasis>

C-phycocyanin (C-PC) was extracted from fresh Spirulina platensis by deploying a species of non-pathogenic nitrogen-fixing bacteria, namely, Klebsiella pneumoniae. The algal slurry was neither washed nor centrifuged; the bacterial culture was poured into the slurry, the vessel sealed, and crude C-PC extracted after about 24 h. The extraction was clean and efficient, and the purity and concentration of C-PC proved to be of adequate quality.     

Nitrate and phosphate removal by<Emphasis Type="Italic"> Spirulina platensis</Emphasis>

The cyanobacterium Spirulina platensis was used to verify the possibility of employing microalgal biomass to reduce the contents of nitrate and phosphate in wastewaters. Batch tests were carried out in 0.5 dm³ Erlenmeyer flasks under conditions of light limitation (40 mol quanta m^–2 s^–1) at a starting biomass level of 0.50 g/dm³ and varying temperature in the range 23–40°C. In this way, the best temperature for the growth of this microalga (30°C) was determined and the related thermodynamic parameters were estimated. All removed nitrate was used for biomass growth (biotic removal), whereas phosphate appeared to be removed mainly by chemical precipitation (abiotic removal). The best results in terms of specific and volumetric growth rates ( =0.044 day^–1, Q _x =33.2 mg dm^–3 day^–1) as well as volumetric rate and final yield of nitrogen removal ( =3.26 mg dm^–3 day^–1, =0.739) were obtained at 30°C, whereas phosphorus was more effectively removed at a lower temperature. In order to simulate full-scale studies, batch tests of nitrate and phosphate removal were also performed in 5.0 dm³ vessels (mini-ponds) at the optimum temperature (30°C) but increasing the photon fluence rate to 80 mol quanta m^–2 s^–1 and varying the initial biomass concentration from 0.25 to 0.86 g/dm³. These additional tests demonstrated that an increase in the inoculum level up to 0.75 g/dm³ enhanced both NO₃ ^– and PO₄ ^3– removal, confirming a strict dependence of these processes on biomass activity. In addition, the larger surface area of the ponds and the higher light intensity improved removal yields and kinetics compared to the flasks, particularly concerning phosphorus removal ( =0.032–0.050 day^–1, Q _x =34.7–42.4 mg dm^–3 day^–1, =3.24–4.06 mg dm^–3 day^–1, =0.750–0.879, =0.312–0.623 mg dm^–3 day^–1, and =0.224–0.440).     

Evaluation of the toxicity of <Emphasis Type="Italic">Arthrospira</Emphasis> (<Emphasis Type="Italic">Spirulina</Emphasis>) <Emphasis Type="Italic">platensis</Emphasis> extract

In this study, the methanol extract of Arthrospira (Spirulina) platensis was examined for acute and subchronic toxicities. The extract did not produce any sign of toxicity within 7 days after feeding it at a single high dose of 6 g kg⁻¹ body weight to female and male Swiss mice. For the subchronic toxicity test, the extract at doses of 6, 12, and 24 mg kg⁻¹ body weight was orally administered to six male and six female Wistar rats daily for 12 weeks. Throughout the study period, we did not observe any abnormalities on behavior, food and water intakes, and health status among the treated animals. The hematology and clinical chemistry parameters of treated groups did not significantly differ from those of the controls in both sexes. Postmortem examination of the test groups also showed no abnormalities in both gross and histological findings. These results thus suggest that the methanol extract of A. platensis did not cause acute or subchronic toxicity in our experimental animals.     

Separation of phycocyanin from <Emphasis Type="Italic">Spirulina platensis</Emphasis> using ion exchange chromatography

This paper presents the evaluation of some important parameters for the purification of phycocyanin using ion exchange chromatography. The influences of pH and temperature on the equilibrium partition coefficient were investigated to establish the best conditions for phycocyanin adsorption. The equilibrium isotherm for the phycocyanin-resin system was also determined. The separation of phycocyanin using the Q-Sepharose ion exchange resin was evaluated in terms of the pH and elution volume that improved the increase in purity and recovery. The highest partition coefficients were obtained in the pH range from 7.5 to 8.0 at 25 degrees C. Under these conditions the equilibrium isotherm for phycocyanin adsorption was well described by the Langmuir model, attaining a Q (m) of 22.7 mg/mL and K (d) of 3.1 x 10(-2) mg/mL. The best conditions for phycocyanin purification using the ion exchange column were at pH 7.5 with an elution volume of 36 mL, obtaining 77.3% recovery and a 3.4-fold increase in purity.     

Enhancement of antioxidant production in <Emphasis Type="Italic">Spirulina platensis</Emphasis> under oxidative stress

The present study examined the possibility of increasing the contents of some bioactive compounds of Spirulina platensis cultivated in medium containing various hydrogen peroxide concentrations (2, 4, 6 and 8 mM) as a model for environmental stress. A positive correlation was observed between the increase of H₂O₂ and increasing amounts of cellular lipophilic antioxidants (total carotenoids and α-tocopherol) and hydrophilic antioxidants [glutathione (GSH) and ascorbic acid (AsA)]. HPLC profile of carotenoids revealed that algae responded to the change of H₂O₂ exposure by the accumulation of higher amounts of β-carotene, astaxanthine, luteine, zeaxanthin and cryptoxanthin. S. platensis showed significant linear increase in activities of antioxidant enzymes, i.e., catalase (CAT), peroxidase (PX), ascorbate peroxidase (APX) and superoxide dismutase (SOD), with increasing H₂O₂ concentrations. A pronounced increase of oxidative lesions’ indexes [thiobarbituric acid reactive substances (TBARS) and paramagnetic radical-EPR signal] was found in algal grown at 8 mM H₂O₂. These data revealed that S. platensis behaved with different strategies against H₂O₂ exposure which is dose dependent and their response strongly correlated with the scavenging enzymes (SOD, CAT, PX and APX) and antioxidant compounds (GSH, AsA, β-carotene, astaxanthine and α-tocopherol) in the antioxidant defense systems. Therefore, S. platensis could be considered as good candidates for successful cultivation in artificial open ponds under different environmental conditions, as high value health foods, functional foods and as source of wide spectrum of nutrients.     

<Emphasis Type="Italic">Ty</Emphasis>1<Emphasis Type="Italic">/copia</Emphasis>- and <Emphasis Type="Italic">Ty</Emphasis>3<Emphasis Type="Italic">/gypsy</Emphasis>-like DNA sequences in <Emphasis Type="Italic">Helianthus </Emphasis>species

Two repeated DNA sequences isolated from a partial genomic DNA library of Helianthus annuus, p HaS13 and p HaS211, were shown to represent portions of the int gene of a Ty3 /gypsy retroelement and of the RNase-Hgene of a Ty1 /copia retroelement, respectively. Southern blotting patterns obtained by hybridizing the two probes to BglII- or DraI-digested genomic DNA from different Helianthus species showed p HaS13 and p HaS211 were parts of dispersed repeats at least 8 and 7 kb in length, respectively, that were conserved in all species studied. Comparable hybridization patterns were obtained in all species with p HaS13. By contrast, the patterns obtained by hybridizing p HaS211 clearly differentiated annual species from perennials. The frequencies of p HaS13- and p HaS211-related sequences in different species were 4.3x10(4)-1.3x10(5) copies and 9.9x10(2)-8.1x10(3) copies per picogram of DNA, respectively. The frequency of p HaS13-related sequences varied widely within annual species, while no significant difference was observed among perennial species. Conversely, the frequency variation of p HaS211-related sequences was as large within annual species as within perennials. Sequences of both families were found to be dispersed along the length of all chromosomes in all species studied. However, Ty3 /gypsy-like sequences were localized preferentially at the centromeric regions, whereas Ty1/ copia-like sequences were less represented or absent around the centromeres and plentiful at the chromosome ends. These findings suggest that the two sequence families played a role in Helianthusgenome evolution and species divergence, evolved independently in the same genomic backgrounds and in annual or perennial species, and acquired different possible functions in the host genomes.     

Photoregulation of morphological structure and its physiological relevance in the cyanobacterium <Emphasis Type="Italic">Arthrospira</Emphasis> (<Emphasis Type="Italic">Spirulina</Emphasis>) <Emphasis Type="Italic">platensis</Emphasis>

The spiral structure of the cyanobacterium Arthrospira (Spirulina) platensis (Nordst.) Gomont was previously found to be altered by solar ultraviolet radiation (UVR, 280–400 nm). However, how photosynthetic active radiation (PAR, 400–700 nm) and UVR interact in regulating this morphological change remains unknown. Here, we show that the spiral structure of A. platensis (D-0083) was compressed under PAR alone at 30°C, but that at 20°C, the spirals compressed only when exposed to PAR with added UVR, and that UVR alone (the PAR was filtered out) did not tighten the spiral structure, although its presence accelerated morphological regulation by PAR. Their helix pitch decreased linearly as the cells received increased PAR doses, and was reversible when they were transferred back to low PAR levels. SDS-PAGE analysis showed that a 52.0 kDa periplasmic protein was more abundant in tighter filaments, which may have been responsible for the spiral compression. This spiral change together with the increased abundance of the protein made the cells more resistant to high PAR as well as UVR, resulting in a higher photochemical yield.     

<Emphasis Type="Italic">Arthrospira</Emphasis> (<Emphasis Type="Italic">Spirulina</Emphasis>) <Emphasis Type="Italic">platensis</Emphasis> extract improves oxidative stability and product quality of Chinese-style pork sausage

Arthrospira (Spirulina) platensis extract (APE) was used as a natural antioxidant in Chinese-style sausage during storage at 4 °C for 18 days. As compared to control, we examined the effect of APE on physical, chemical, microbiological, and sensory qualities of sausages, as well as on change in pH, color, thiobarbituric value (TBARS), volatile basic nitrogen (VBN), and total viable counts of mesophilic and psychrotrophic bacteria. The sensory qualities including color, aroma, taste, texture, and overall acceptability were evaluated. It was found that APE sausages displayed lower changes in pH, lightness (L*), redness (a*), yellowness (b*), TBARS value, and sensory attributes than control. However, there was no significant difference in VBN and microbiological status between APE and control sausages. Successful inhibition of lipid oxidation in samples was possible with the incorporation of APE in the refrigerated Chinese-style sausages. Our results suggest that the incorporation of APE into Chinese-style pork sausages enhance the antioxidant and maintains product quality.     

Preparation and regeneration of spheroplasts from <Emphasis Type="BoldItalic">Arthrospira</Emphasis><Emphasis Type="BoldItalic">platensis</Emphasis> (Spirulina)

Ultrasonic pretreatment, lysozyme, inorganic osmotics and bovine albumin were used to prepare the spheroplasts of Arthrospira platensis (Spirulina platensis). The average cell number of the fragments from the filaments of strain A9 was about 2.2 cells after 80-s ultrasonic pretreatment. These fragments could regenerate and were suitable material for isolating spheroplasts, so the optimum conditions for doing this were investigated. The best enzymolysis parameters were designed. During the isolation process, gentle shaking of the enzymolysis sample for several times greatly enhanced the proportion of spheroplasts. However, no spheroplasts were obtained when organic compounds were used as osmotics. The spheroplasts could form typical colonies on plate of inorganic medium, with a regeneration rate of about 3%. These spheroplasts might be used as competence cells to carry on the research of genetic transformation.     

Identification of microRNA-size sRNAs Related to Salt Tolerance in <Emphasis Type="Italic">Spirulina platensis</Emphasis>

microRNAs (miRNAs) are endogenous non-coding small RNAs (sRNA) that play important regulatory functions in growth, development, and environmental stress response of eukaryotes. Currently, miRNA-size sRNA (msRNAs) was discovered in several prokaryotes through deep sequencing. However, no data are available on whether msRNAs exist in cyanobacteria and whether they regulate biological tolerance to salt stress. In this study, three small RNA libraries were constructed from control (0.02 M NaCl), medium- (0.3 M NaCl), and high-salt treatments (0.5 M NaCl) of Spirulina platensis. After sequencing using a high-throughput Illumina Solexa system, nine msRNAs with msRNA* were identified, and 21 candidate msRNAs showed significantly differential expression under salt-stress conditions. Seven of the selected msRNAs presented the consistent expression trends when compared with their deep sequencing results as verified by quantitative real-time polymerase chain reaction (qRT-PCR), demonstrating that the expression analyses for msRNAs according to small RNA sequencing data were reliable. Through computational identification, 33 target genes were predicted for 12 msRNAs in S. platensis; Gene Ontology (GO) and KEGG enrichment analyses revealed that the putative target genes were grouped into the categories of proteolysis, protein homotrimerization, glycosylation, ubiquinone biosynthetic process, DNA restriction-modification system, and polysaccharide catabolic process. Using proteomic analysis, two target proteins (glyceraldehyde-3-phosphate dehydrogenase and forkhead-associated (FHA) domain-containing protein) were differentially expressed under salt-stress conditions, which might be regulated by msRNAs. Our study demonstrates that msRNAs exist in S. platensis, and these msRNAs may have an important role in salt-stress responses; however, their functional significance requires further investigation.     

<Emphasis Type="Italic">Agrobacterium</Emphasis><Emphasis Type="Italic">tumefaciens</Emphasis>-mediated transformation of callus cells of <Emphasis Type="Italic">Crataegus</Emphasis><Emphasis Type="Italic">aronia</Emphasis>

A genetic transformation system has been developed for callus cells of Crataegus aronia using Agrobacterium tumefaciens. Callus culture was established from internodal stem segments incubated on Murashige and Skoog (MS) medium supplemented with 5 mg l⁻¹ Indole-3-butyric acid (IBA) and 0.5 mg l⁻¹ 6-benzyladenine (BA). In order to optimize the callus culture system with respect to callus growth and coloration, different types and concentrations of plant growth regulators were tested. Results indicated that the best average fresh weight of red colored callus was obtained on MS medium supplemented with 2 mg l⁻¹ 2,4-dichlorophenoxyacetic acid (2,4-D) and 1.5 mg l⁻¹ kinetin (Kin) (callus maintenance medium). Callus cells were co-cultivated with Agrobacterium harboring the binary plasmid pCAMBIA1302 carrying the mgfp5 and hygromycin phosphotransferase (hptII) genes conferring green fluorescent protein (GFP) activity and hygromycin resistance, respectively. Putative transgenic calli were obtained 4 weeks after incubation of the co-cultivated explants onto maintenance medium supplemented with 50 mg l⁻¹ hygromycin. Molecular analysis confirmed the integration of the transgenes in transformed callus. To our knowledge, this is the first time to report an Agrobacterium-mediated transformation system in Crataegus aronia.     

Production of <Emphasis Type="Italic">cis</Emphasis>-Vaccenic Acid-oriented Unsaturated Fatty Acid in <Emphasis Type="Italic">Escherichia coli</Emphasis>

Biodiesel is produced worldwide as an alternative energy fuel and substitute for petroleum. Biodiesel is often obtained from vegetable oil, but production of biodiesel from plants requires additional land for growing crops and can affect the global food supply. Consequently, it is necessary to develop appropriate microorganisms for the development of an alternative biodiesel feedstock. Escherichia coli is suitable for the production of biodiesel feedstocks since it can synthesize fatty acids for lipid production, grows well, and is amenable to genetic engineering. Recombinant E. coli was designed and constructed for the production of biodiesel with improved unsaturated fatty acid contents via regulation of the FAS pathway consisting of initiation, elongation, and termination steps. Here, we investigated the effects of fabA, fabB, and fabF gene expression on the production of unsaturated fatty acids and observed that the concentration of cis-vaccenic acid, a major component of unsaturated fatty acids, increased 1.77-fold compared to that of the control strain. We also introduced the genes which synthesize malonyl-ACP used during initiation step of fatty acid synthesis and the genes which produce free fatty acids during termination step to study the effect of combination of genes in elongation step and other steps. The total fatty acid content of this strain increased by 35.7% compared to that of the control strain. The amounts of unsaturated fatty acids and cis-vaccenic acid increased by 3.27 and 3.37-fold, respectively.     

Revision of the <Emphasis Type="Italic">Serrulati</Emphasis> species of <Emphasis Type="Italic">Penstemon</Emphasis> section <Emphasis Type="Italic">Saccanthera</Emphasis> subsection <Emphasis Type="Italic">Serrulati</Emphasis>

A revision of Penstemon sect. Saccanthera subsect. Serrulati includes a new species (P. salmonensis), a new variety (P. triphyllus var. infernalis), and the elevation of a subspecies to species (P. curtiflorus), bringing the total number of species to eight, which are keyed and described, complete with nomenclature and type citations.     

The <Emphasis Type="Italic">Caenorhabditis</Emphasis><Emphasis Type="Italic">briggsae</Emphasis> genome contains active <Emphasis Type="Italic">CbmaT1</Emphasis> and <Emphasis Type="Italic">Tcb1</Emphasis> transposons

The maT clade of transposons is a group of transposable elements intermediate in sequence and predicted protein structure to mariner and Tc transposons, with a distribution thus far limited to a few invertebrate species. We present evidence, based on searches of publicly available databases, that the nematode Caenorhabditis briggsae has several maT-like transposons, which we have designated as CbmaT elements, dispersed throughout its genome. We also describe two additional transposon sequences that probably share their evolutionary history with the CbmaT transposons. One resembles a fold back variant of a CbmaT element, with long (380-bp) inverted terminal repeats (ITRs) that show a high degree (71%) of identity to CbmaT1. The other, which shares only the 26-bp ITR sequences with one of the CbmaT variants, is present in eight nearly identical copies, but does not have a transposase gene and may therefore be cross mobilised by a CbmaT transposase. Using PCR-based mobility assays, we show that CbmaT1 transposons are capable of excising from the C. briggsae genome. CbmaT1 excised approximately 500 times less frequently than Tcb1 in the reference strain AF16, but both CbmaT1 and Tcb1 excised at extremely high frequencies in the HK105 strain. The HK105 strain also exhibited a high frequency of spontaneous induction of unc-22 mutants, suggesting that it may be a mutator strain of C. briggsae.     

<Emphasis Type="Italic">Galleria</Emphasis><Emphasis Type="Italic">mellonella</Emphasis> are Resistant to <Emphasis Type="Italic">Pneumocystis</Emphasis><Emphasis Type="Italic">murina</Emphasis> Infection

Studying Pneumocystis has proven to be a challenge from the perspective of propagating a significant amount of the pathogen in a facile manner. The study of several fungal pathogens has been aided by the use of invertebrate model hosts. Our efforts to infect the invertebrate larvae Galleria mellonella with Pneumocystis proved futile since P. murina neither caused disease nor was able to proliferate within G. mellonella. It did, however, show that the pathogen could be rapidly cleared from the host.     

Effect of microalgae hydrolysate foliar application (<Emphasis Type="Italic">Arthrospira platensis</Emphasis> and <Emphasis Type="Italic">Scenedesmus</Emphasis> sp.) on <Emphasis Type="Italic">Petunia x hybrida</Emphasis> growth

In horticultural practice accelerated plant development and particularly earlier flowering, has been reported with microalgae applications. Therefore, the objective of this work was to study the effects of foliar spraying with Scenedesmus sp. and Arthrospira platensis hydrolysates on Petunia x hybrida plant development and leaf nutrient status. Three treatments were tested: T1 (foliar application with water, the control), T2 (foliar application with Arthrospira), and T3 (foliar application with Scenedesmus). Foliar spraying was applied five times (0, 14, 28, 35, and 42 days after transplanting). The concentration of both microalgae was 10 g L^?1. At the end of the trial biometric parameters and nutrient concentration in photosynthetic organs (the leaves) were measured. The results of this assay show that foliar application of Scenedesmus accelerated plant development in terms of higher rates of root growth, leaf and shoot development, and earliness of flowering. Arthrospira enhanced the root dry matter, the number of flowers per plant, and the water content. Nevertheless, a reduction was found in the conductive tissue (stem + petiole) dry weight with Arthrospira compared with Scenedesmus and the control. The results also show that microalgae hydrolysate supply can improve the plant nutrient status. Based on these results, it is advisable to use Scenedesmus hydrolysates in foliar applications to increase the blooming of Petunia x hybrida.     

New combinations and typifications in <Emphasis Type="Italic">Bistorta</Emphasis>, <Emphasis Type="Italic">Persicaria</Emphasis>, <Emphasis Type="Italic">Polygonum,</Emphasis> and <Emphasis Type="Italic">Rumex</Emphasis> (Polygonaceae)

New combinations are proposed in anticipation of the Polygonaceae treatment in the forthcoming volume of Intermountain Flora: Polygonum kelloggii var. esotericum, P. kelloggii var. watsonii , Rumex densiflorus var. pycnanthus , R. salicifolius var. utahensis, and R. occidentalis var. tomentellus. Typifications are proposed to facilitate ongoing studies in Polygonaceae and to maintain current usage.