Productivity and organic consumption in Cassiopea and Condylactus

Oxygen production and consumption was determined for Cassiopea and Condylactus containing symbiotic algae (zooxanthellae). 88 % of both animals produce more organic material than they consumed during a 12-h light period.It is suggested that zooxanthellae contribute a significant nutritional supplementation and a greater ecological efficiency to the host animals.     

Motility of zooxanthellae isolated from the Red Sea soft coral Heteroxenia fuscescens (Cnidaria)

Unicellular dinoflagellate algae are among the best examples of organisms that exhibit biological clocks. This study examined the effect of light regime on rhythmicity of motility in the symbiotic dinoflagellate Symbiodinium sp., freshly isolated from the soft coral Heteroxenia fuscescens (Ehrenberg). Freshly isolated algal cells, placed under a 12-h L:12-h D cycle, exhibited motility with a diel rhythm. This motility occurred only during the period of illumination and lasted 8-9 h, with a peak at 2.5-4 h after lights on. Algal cells placed in an inverted light regime inverted their motility pattern. The response to the L/D regime was very precise, and even a 1-h shift backward or forward affected initiation of motility and time of its maximal peak. When placed in either constant light or dark, algal motility ceased until the L/D cycle was restored. These findings suggest that the rhythm is entrained by light cues and is not due to an endogenous circadian rhythm. Further, we provide evidence that the presence of juvenile hosts does not affect the algal motility pattern. These results offer the first evidence for the lack of impact by the host on rhythmicity of motility of free-living algal cells. The motility pattern found in freshly isolated algae may indicate the presence of light-induced diel rhythmicity in yet-to-be described free-living Symbiodinium.     

Two new Beauveria spp. from South America

Beauveria velata sp. nov. was found on Lepidoptera larvae in Ecuador and is characterized by ellipsoid conidia covered with a distinct mucilaginous layer. Another Beauveria species, commonly encountered on Coleoptera in Brazil proved to be identical with Isaria amorpha Höhn., originally described from a cicada in Indonesia. The new combination Beauveria amorpha is proposed. Details of the occurrence and ecology of both species are described.     

Heterorhabditis spp., Neoaplectana spp., and Steinernema kraussei: Interspecific and intraspecific differences in infectivity for insects

The effectiveness of various dosages of different species/strains of nematodes was compared for Galleria mellonella and various pest insects that live in or pupate in soil. Neoaplectana feltiae (= carpocapsae), the only nematode species tested by most other workers, was never the most infective for any of the insect species tested and was least infective for two. All species/strains of nematode were able to kill insects of each species. The degree of infectivity of each of the nematode species/strains for different hosts varied considerably, and no one species/strain of nematode was the most infective for all insect species. This indicates the importance of testing a number of nematode species against any particular insect before commencing field evaluations for biological control.     

Phenolic constituents of Artemesia tridentata spp. Vaseyana

Ten coumarins and four flavonoids have been isolated from a single collection of Artemesia tridentata ssp. vaseyana (Rydb.) Beetle. The coumarins are 7-methylesculin, esculin, umbelliferone, skimmin, cichoriin, isoscopoletin, scopoletin, scoparon, esculetin and a new natural product, artelin (5,6,7,8-tetramethoxy coumarin). The flavonoids are luteolin, luteolin-7-glucoside, axillarin and eupafolin.     

Depolymerised carrageenan enhances physiological activities and menthol production in Mentha arvensis L.

Irradiated carrageenan (IC) could elicit plant growth promoting activities in plants. The effect of foliar spray of five concentrations of IC (20, 40, 60_, 80 and 100 mg L⁻¹) was studied on Mentha arvensis L. in terms of plant growth, physiological attributes, herbage yield and the content and yield of essential oil and its components. Un-irradiated carrageenan and deionized water had no effect on the attributes studied. GPC study revealed formation of low molecular weight fractions in irradiated samples containing less than 20,000 molecular weight oligomers which are responsible for plant growth promotion in this study. 80 mg L⁻¹ of IC was the most effective concentration which resulted in the highest values of growth attributes, herbage yield and the content and yield of essential oil and menthol content of the oil. It also improved the leaf-nutrient contents, photosynthetic rate and other physiological parameters. 100 mg L⁻¹ of IC did not further improve the attributes studied, but it was always better than the control.     

Enzymatically derived aldouronic acids from Cryptomeria japonica arabinoglucuronoxylan

An arabinoglucuronoxylan was extracted from the holocellulose of sugi (Cryptomeria japonica) wood with 10% KOH and subjected to hydrolysis by partially purified xylanase fraction from a commercial cellulase preparation “Meicelase”. Neutral sugars liberated were analyzed by size exclusion chromatography showing the presence of xylooligosaccharides up to xylohexaose. Aldouronic acids liberated were purified by preparative anion exchange chromatography. Their structures were identified by monosaccharide analysis, comparison of their volume distribution coefficients (Dvs) with those of the authentic samples in anion exchange chromatography and ¹H and ¹³C NMR spectroscopy, resulting in the characterization of eight aldouronic acids including acids consisting of two 4-O-Me-α-D-GlcAp residues and 3-5 D-Xyl residues.

1.

Fr. 1-S1: (aldohexaouronic acid, MeGlcA³Xyl₅), O-β-Xylp-(1 → 4)-O-β-D-Xylp-(1 → 4)-[O-(4-O-Me-α-D-GlcAp)-(1 → 2)]-O-β-Xylp-(1 → 4)-O-β-D-Xylp-(1 → 4)-D-Xyl

2.

Fr. 1-S2: (aldopentaouronic acid, MeGlcA³Xyl₄), O-β-Xylp-(1 → 4)-[O-(4-O-Me-α-D-GlcAp)-(1 → 2)]-O-β-D-Xylp-(1 → 4)-O-β-Xylp-(1 → 4)-D-Xyl

3.

Fr. 2-S1: (aldotetraouronic acid, MeGlcA³Xyl₃), O-(4-O-Me-α-D-GlcAp)-(1 → 2)-O-β-D-Xylp-(1 → 4)-O-β-D-Xylp-(1 → 4)-D-Xyl

4.

Fr. 3-S1: (aldotetraouronic acid, GlcA³Xyl₃), O-(α-D-GlcAp)-(1 → 2)-O-β-D-Xylp-(1 → 4)-O-β-Xylp-(1 → 4)-D-Xyl,

5.

Fr. 4-S1: (aldotriouronic acid, GlcA²Xyl₂), O-(4-O-Me-α-D-GlcAp)-(1 → 2)-O-β-D-Xylp-(1 → 4)-D-Xyl

6.

Fr. 4-S2: (MeGlc⁴MeGlcA³Xyl₅), O-β-D-Xylp-(1 → 4)-[O-(4-O-Me-α-D-GlcAp)]-(1 → 2)-O-β-D-Xylp-(1 → 4)-[O-(4-O-Me-α-D-GlcAp)]-(1 → 2)-O-β-D-Xylp-(1 → 4)-O-β-D-Xylp-(1 → 4)-D-Xyl

7.

Fr. 6-S1: (MeGlcA⁴MeGlcA³Xyl₄), O-(4-O-Me-α-D-GlcAp)-(1 → 2)-O-β-D-Xylp-(1 → 4)-O-[(4-O-Me-α-D-GlcAp)]-(1 → 2)-O-β-D-Xylp-(1 → 4)-O-β-D-Xylp-(1 → 4)-D-Xyl

8.

Fr. 7-S1: (MeGlcA³MeGlc²Xyl₃), O-(4-O-Me-α-D-GlcAp)-(1 → 2)-O-β-D-Xylp-(1 → 4)-O-[(4-O-Me-α-D-GlcAp)]-(1 → 2)-O-β-D-Xylp-(1 → 4)-D-Xyl

Fr. 4-S2 was a new acidic oligosaccharide. The distribution pattern of these vicinal uronic acid units along the D-xylan chain was discussed.     

The expulsion of Aspiculuris tetraptera and syphacia spp. from mice after anthelmintic treatment

The expulsion of Aspiculuris tetraptera and Syphacia spp. from mice after anthelmintic treatment. International Journal for Parasitology10: 205–211. The effect of four benzimidazoles, piperazine and levamisole on the expulsion of adult Aspiculuris tetraptera and Syphacia spp. from mice is described on a quantitative basis. Levamisole and piperazine were found to initiate expulsion within a few hours, but this ceased by 24 h. Following benzimidazole treatment most pinworms were expelled between 24 and 48 h. Syphacia spp. responded earlier to the benzimidazoles than did A. tetraptera, but later to levamisole; both species responded similarly to piperazine. Only levamisole and mebendazole were completely effective against both species within 24 h, piperazine being the least effective. The in vitro effects of levamisole on the motility and the recovery from drug-induced paralysis of the same nematode species are also reported.     

Genetic characterisation of uninucleated cyst-producing Entamoeba spp. from ruminants

Six ssrRNA gene sequences were obtained by PCR amplification of DNA from uninucleated Entamoeba cysts isolated from fresh faeces of sheep, cows, a roe deer and a reindeer. Phylogenetic analysis using sequences of non-, uni-, quadri- and octonucleate cyst-producing Entamoeba spp. for comparison showed that all six isolates formed a separate clade nested within the clade of quadrinucleate cyst producers. The data indicate that Entamoeba bovis can be isolated from ruminant hosts other than cattle, and we suggest that organisms clustering with the sheep and cattle isolates analysed in the present study be named E. bovis.     

Nutrient availability and pH jointly constrain microbial extracellular enzyme activities in nutrient-poor tundra soils

Background and aims

Tundra soils, which usually contain low concentrations of soil nutrients and have a low pH, store a large proportion of the global soil carbon (C) pool. The importance of soil nitrogen (N) availability for microbial activity in the tundra has received a great deal of attention; however, although soil pH is known to exert a considerable impact on microbial activities across ecosystems, the importance of soil pH in the tundra has not been experimentally investigated.

Methods

We tested a hypothesis that low nutrient availability and pH may limit microbial biomass and microbial capacity for organic matter degradation in acidic tundra heaths by analyzing potential extracellular enzyme activities and microbial biomass after 6 years of factorial treatments of fertilization and liming.

Results

Increasing nutrients enhanced the potential activity of β-glucosidase (synthesized for cellulose degradation). Increasing soil pH, in contrast, reduced the potential activity of β-glucosidase. The soil phospholipid fatty acid concentrations (PLFAs; indicative of the amount of microbial biomass) increased in response to fertilization but were not influenced by liming.

Conclusions

Our results show that soil nutrient availability and pH together control extracellular enzyme activities but with largely differing or even opposing effects. When nutrient limitation was alleviated by fertilization, microbial biomass and enzymatic capacity for cellulose decomposition increased, which likely facilitates greater decomposition of soil organic matter. Increased soil pH, in contrast, reduced enzymatic capacity for cellulose decomposition, which could be related with the bioavailability of organic substrates.     

In vitro antioxidant and antitumor activities of polysaccharides extracted from Asparagus officinalis

Ultrasonic circulating extraction technology was applied for the polysaccharide extraction from Asparagus officinalis. The crude polysaccharides were deproteinized by Sevag method and three main polysaccharide fractions, AOP-4, AOP-6 and AOP-8 were obtained by fractional precipitation with gradient concentrations of ethanol (40%, 60% and 80%). The in vitro antitumor and antioxidant activities of the polysaccharide fractions were evaluated by MTT assay and free radical-scavenging assay, respectively. Deproteinized AOPs showed higher antioxidant and antitumor activities than crude AOP. AOP-4 with molecular weight 5.75 × 10⁴ Da showed significant function of scavenging hydroxyl radical. Three AOP fractions had significant antitumor activity against HeLa and BEL-7404 cells in a dose dependent manner. Furthermore, the inhibit activity of AOP-4 against HeLa cells was higher than those of other AOPs and the inhibition rate reached 83.96% at the concentration of 10 mg/mL. These results indicated that the AOP might be useful for developing natural safe antitumor drugs or health food.     

Multilocus typing of Cryptosporidium spp. and Giardia duodenalis from non-human primates in China

Non-human primates (NHPs) are commonly infected with Cryptosporidium spp. and Giardia duodenalis. However, molecular characterisation of these pathogens from NHPs remains scarce. In this study, 2,660 specimens from 26 NHP species in China were examined and characterised by PCR amplification of 18S rRNA, 70 kDa heat shock protein (hsp70) and 60 kDa glycoprotein (gp60) gene loci for Cryptosporidium; and 1,386 of the specimens by ssrRNA, triosephosphate isomerase (tpi) and glutamate dehydrogenase (gdh) gene loci for Giardia. Cryptosporidium was detected in 0.7% (19/2660) specimens of four NHP species including rhesus macaques (0.7%), cynomolgus monkeys (1.0%), slow lorises (10.0%) and Francois’ leaf monkeys (6.7%), belonging to Cryptosporidium hominis (14/19) and Cryptosporidium muris (5/19). Two C. hominis gp60 subtypes, IbA12G3 and IiA17 were observed. Based on the tpi locus, G. duodenalis was identified in 2.2% (30/1,386) of specimens including 2.1% in rhesus macaques, 33.3% in Japanese macaques, 16.7% in Assam macaques, 0.7% in white-headed langurs, 1.6% in cynomolgus monkeys and 16.7% in olive baboons. Sequence analysis of the three targets indicated that all of the Giardia-positive specimens belonged to the zoonotic assemblage B. Highest sequence polymorphism was observed at the tpi locus, including 11 subtypes: three known and eight new ones. Phylogenetic analysis of the subtypes showed that most of them were close to the so-called subtype BIV. Intragenotypic variations at the gdh locus revealed six types of sequences (three known and three new), all of which belonged to so-called subtype BIV. Three specimens had co-infection with C. hominis (IbA12G3) and G. duodenalis (BIV). The presence of zoonotic genotypes and subtypes of Cryptosporidium spp. and G. duodenalis in NHPs suggests that these animals can potentially contribute to the transmission of human cryptosporidiosis and giardiasis.     

Chromone and chromanone glucosides from Hypericumsikokumontanum and their anti-Helicobacter pylori activities

Chromone glucosides, takanechromones A-C (1, 2 and 5) and chromanone glucosides, named takanechromanones A and B (3 and 4), were isolated from the methanolic extracts of Hypericumsikokumontanum together with 27 known compounds. Their structures were established based on spectroscopic evidence. The isolated compounds and some chromone derivatives were assayed for antimicrobial activity against Helicobacter pylori and cytotoxicity against human cancer cell lines.     

Antiplasmodial and other constituents from four Indonesian Garcinia spp.

Phytochemical investigations of four Garcinia spp. from Indonesia, i.e. Garcinia griffithii T. Anderson, Garcinia celebica L., Garcinia cornea L. and Garcinia cymosa K. Schum (Clusiaceae), have resulted in the isolation of a xanthone, 1,5-dihydroxy-3,6-dimethoxy-2,7-diprenylxanthone, 1,7-dihydroxyxanthone, isoxanthochymol, β-sitosterol-3-O-β-d-glucoside and stigmasterol-3-O-β-d-glucoside from the stem bark of G. griffithii; friedelin and 3β-hydroxy-23-oxo-9,16-lanostadien-26-oic acid or garcihombronane D from leaves of G. celebica; 23-hydroxy-3-oxo-cycloart-24-en-26-oic acid and epicatechin from stem bark of G. cornea; (±)-morelloflavone, morelloflavone-7-O-β-d-glucoside or fukugiside, the triterpene 3β-hydroxy-5-glutinen-28-oic acid and canophyllol from stem bark of G. cymosa. The xanthone and garcihombronane D displayed a selective activity against Plasmodium falciparum; isoxanthochymol and the triterpene β-hydroxy-5-glutinen-28-oic acid a broad but non-selective antiprotozoal activity.     

A simple method for the extraction and quantification of photopigments from Symbiodinium spp.

We have developed a simple, mild extraction procedure using methanol which, when coupled with HPLC analysis and diode array detection (DAD), can be used to quantify the major photopigments found in cultured Symbiodinium spp. Extracts were prepared by suspending, fresh or frozen (− 70 °C), wet cell pellets in methanol and sonicating or not sonicating the cell suspensions before soaking the cells for 2 h in an ice bath. To assist the soaking process, cell suspensions were vortex mixed at 30 min intervals. After soaking, 0.5 M ammonium acetate buffer was added (1 part buffer to 9 parts methanol) before suspensions were stored over night at − 20 °C. Greater than 92% the recoverable pigment was obtained in the initial extraction of the four major photopigments, chlorophyll c, peridinin, diadinoxanthin, and chlorophyll a. Neither sonication nor freezing substantially increased the recovery of photopigments extracted with methanol. Extraction by other commonly used solvents such as acetone or acetone:water with or without freezing and sonication were less effective.     

Genotyping, physiological features and proteolytic activities of a potentially pathogenic Acanthamoeba sp. isolated from tap water in Brazil

Acanthamoeba spp., known to cause keratitis and granulomatous encephalitis in humans, are frequently isolated from a variety of water sources. Here we report for the first time the characterization of an Acanthamoeba sp. (ACC01) isolated from tap water in Brazil. This organism is currently being maintained in an axenic growth medium. Phylogenetic analysis based on SSU rRNA gene sequences positioned the new isolate in genotype T4, closest to the keratitis-causing isolate, A. polyphaga ATCC 30461 (∼99% similarity). Acanthamoeba ACC01 and A. polyphaga 30461 both grew at 37 °C and were osmotically resistant, multiplying in hyperosmolar medium. Both isolates secreted comparable amounts of proteolytic enzymes, including serine peptidases that were optimally active at a near neutral/alkaline pH and resolved identically in gelatin gels. Incubation of gels at pH 4.0 with 2 mM DTT also indicated the secretion of similar cysteine peptidases. Altogether, the results point to the pathogenic potential of Acanthamoeba ACC01.     

Role of galE on biofilm formation by Thermus spp.

Thermus thermophilus and Thermus aquaticus are thermophilic bacteria that are frequently found to attach to solid surfaces in hot springs to form biofilms. Uridine diphosphate (UDP)-galactose-4′-epimerase (GalE) is an enzyme that catalyzes the conversion of UDP-galactose to UDP-glucose, an important biochemical step in exopolysaccharide synthesis. We expressed GalE obtained from T. thermophilus HB8 in Escherichia coli and found that the enzyme is stable at 80 °C and can epimerize UDP-galactose to UDP-glucose and UDP-N-acetylgalactosamine (UDP-GalNAc) to UDP-N-acetylglucosamine (UDP-GlcNAc). Enzyme overexpression in T. thermophilus HB27 led to an increased capacity of biofilm production. Therefore, the galE gene is important to biofilm formation because of its involvement in epimerizing UDP-galactose and UDP-N-acetylgalactosamine for exopolysaccharide biosynthesis.     

Structural properties of a peptide derived from H-V-ATPase subunit a

The 3D structure of a peptide derived from the putative transmembrane segment 7 (TM7) of subunit a from H⁺-V-ATPase from Saccharomyces cerevisiae has been determined by solution state NMR in SDS. A stable helix is formed from L736 up to and including Q745, the lumenal half of the putative TM7. The helical region extends well beyond A738, as was previously suggested based on NMR studies of a similar peptide in DMSO. The pKa of both histidine residues that are important for proton transport was measured in water and in SDS. The differences that are found demonstrate that the histidine residues interact with the SDS polar heads. In detergent, circular dichroism data indicate that the secondary structure of the peptide depends on the pH and the type of detergent used. Using solid-state NMR, it is shown that the peptide is immobile in phospholipid bilayers, which means that it is probably not a single transmembrane helix in these samples. The environment is important for the structure of TM7, so in subunit a it is probably held in place by the other transmembrane helices of this subunit.     

Sulfated polysaccharides from Laminaria angustata: Structural features and in vitro antiviral activities

Sulfated polysaccharides potently inhibit the infectivity of herpes simplex virus (HSV) in cultured cells. In this study, we have analyzed sulfated xylogalactofucan and alginic acid containing fractions generated from Laminaria angustata, a marine alga. The xylogalactofucan that has apparent molecular mass of 56 ± 5 kDa and unusually low sulfate content contains, inter alia, 1,3-, 1,4- and 1,2-linked fucopyranosyl residues. The algin (molecular mass: 32 ± 5 kDa) contains gulo- (55.5%) and mannuronic (44.5%) acid residues. Introduction of sulfate groups enhanced the macromolecules capability to inhibit the infection of cells by HSV-1. The 50% inhibitory concentration (IC₅₀) values of these macromolecules against HSV-1 were in the range of 0.2-25 μg ml⁻¹ and they lacked cytotoxicity at concentrations up to 1000 μg ml⁻¹. The sulfate content appeared to be an important hallmark of anti-HSV-1 activity. Our results suggest the feasibility of inhibiting HSV attachment to cells by direct interaction of polysaccharides with viral particles.     

High prevalence of Sarcocystis spp. infections in cattle (Bos taurus) from central China

Myocardium and diaphragm samples of cattle (n?=?521) from HeNan Province (China) were screened for Sarcocystis sarcocysts by histological examination, pepsin digestion, and molecular assays. Morphology and molecular assays were used for identification. The prevalence of Sarcocystis infection in cattle was 41.5% (216/521). Histological examination identified sarcocysts in the myocardium (49.4%, 200/405) and diaphragm (13.8%, 16/116) of cattle. Two species were identified, namely S. cruzi (41.3%, 215/521) and S. hominis (0.2%, 1/521). The findings of the present study indicate a high prevalence of S. cruzi infection in cattle from central China.