In vitro and in silico antifungal efficacy of nitrogen-doped carbon nanohorn (NCNH) against Rhizoctonia solani

We have investigated in vitro antifungal efficiency of nitrogen-doped carbon nanohorn (NCNH) against Rhizoctonia solani (R. solani) plant pathogenic fungi. NCNH with size of 50–60 nm and concentrations of 10, 50, 100, and 150 μg mL^?1 were used. The results showed that growth of fungi in the presence of NCNH was significantly (p > .05) inhibited at 150 μg mL^?1 (85.13 ± .97) after 72 h. The results were validated through computational approaches. Molecular docking analysis of NCNH with endochitinase protein of R. solani was performed to validate the potential of antifungal activity of NCNH. Docking results showed different conformations of interaction of NCNH with endochitinase enzyme. The conformation with least binding energy ?13.54 kcal/mol was considered further. It is likely that NCNH interacts with the pathogens by mechanically wrapping, which may be one of the major toxicity actions of NCNH against R. solani. The analysis showed that NCNH might interwinds to endochitinase of R. solani leading to the deactivation of the enzyme. To best of our knowledge, this is the first report of antifungal efficacy of NCNH against R. solani and provides useful information about the application of NCNH in resisting crop disease.     

Antiviral Action of Methylated β-Lactoglobulin on the Human Influenza Virus A Subtype H3N2

Antiviral activity of methylated β-lactoglobulin (Met-BLG) against H3N2 infected into MDCK cell lines depended on concentration of Met-BLG, viral load, and duration of infection. IC_50% of the hemagglutination activity for 1 and 0.2 MOI (multiplicity of infection) after 24 h of incubation at 37 °C in the presence of 5% CO₂ were 20 ± 0.8 and 17 ± 0.7 μg mL^?1 Met-BLG, respectively. Longer incubation period (4 days) was associated with low IC_50% of the hemagglutination activity (7.1 ± 0.3 μg mL^?1 Met-BLG) and low IC_50% of immuno-fluorescence of viral nucleoproteins (9.7 ± 0.4 μg mL^?1 Met-BLG) when using 0.2 and 0.1 MOI, respectively. A concentration of 25 μg mL^?1 of Met-BLG reduced the amount of replicating virus by about 2 and 1.3 logs when the viral load was 0.01 and 0.1 MOI, respectively, while higher concentrations reduced it by about 5–6 logs. Antiviral action of Met-BLG was coupled with a cellular protective action, which reached 100% when using 0.01 and 0.1 MOI and 83% when using 1.0 MOI. The time of Met-BLG addition after the viral infection was determinant for its antiviral efficacy and for its protection of the infected MDCK cell lines. Anti-hemagglutination action and cell protective action decreased gradually and in parallel with the delay in the time of Met-BLG addition to disappear totally after 10 h delay.     

Spontaneous mutation frequency and molecular mechanisms of Shigella flexneri fluoroquinolone resistance under antibiotic selective stress

The incidence of fluoroquinolone-resistant Shigella strains has risen rapidly, presumably in response to ciprofloxacin antibiotic stress. Understanding the molecular mechanisms underlying this resistance phenotype is critical to developing novel and effective therapeutic strategies. In this study, the frequency of ciprofloxacin-induced mutation was measured in antibiotic resistance genes (gyrA, gyrB, parC, parE, marOR, and marA) of Shigella flexneri. The S. flexneri 2a strain 301 was cultured on Luria–Bertani agar plates containing one of seven different ciprofloxacin concentrations (range: 0.03125–2 μg mL^?1). Resistant colonies were selected for gene-targeted sequencing analysis; the identified point mutations were subsequently confirmed by insertion into antibiotic cassette plasmids and growth under ciprofloxacin stress. The results demonstrated that the seven different ciprofloxacin concentrations produced dose-dependent frequencies of spontaneous mutations: 10^?8 (0.03125 and 0.0625 μg mL^?1), 10^?9 (0.125 μg mL^?1), and <10^?9 (0.25, 0.5, 1, 2 μg mL^?1). PCR sequencing of the ten randomly selected resistant colonies (minimum inhibitory concentrations (MICs) of 0.125 μg mL^?1, n = 5 and 0.25 μg mL^?1, n = 5) revealed that all colonies had mutations in the gyrA gene at either codon 83 (Ser83 → Leu) or 87 (Asp87 → Tyr or → Gly), both of which were confirmed at MIC of 0.125 μg mL^?1. None of the spontaneous mutation colonies exhibited gyrB, parC, parE, marOR, or marA mutations. In conclusion, S. flexneri is normomutable under ciprofloxacin antibiotic stress and fluoroquinolone resistance by spontaneous mutation occurs at a low rate. Codon mutations gyrA 83 and/or gyrA 87 cause a 4-fold increase in the ciprofloxacin MIC, and may represent the natural mechanism of fluoroquinolone resistance.     

Chitosan and a fungal elicitor inhibit tracheary element differentiation and promote accumulation of stress lignin-like substance in Zinnia elegans xylogenic culture

We investigated the effect of elicitors on xylem differentiation and lignification using a Zinnia elegans xylogenic culture system. Water-soluble chitosan and a fungal elicitor derived from Botrytis cinerea were used as elicitors. Elicitor addition at the start of culturing inhibited tracheary element (TE) differentiation in a concentration-dependent manner, and 30 μg mL^?1 of chitosan or 16.7 μg mL^?1 of the fungal elicitor strikingly inhibited TE differentiation and lignification. Addition of chitosan (at 50 μg mL^?1) or the fungal elicitor (at 16.7 μg mL^?1) during the culturing period also inhibited TE differentiation without inhibiting cell division, except for immature TEs undergoing secondary wall thickening. Elicitor addition after immature TE appearance also caused the accumulation of an extracellular lignin-like substance. It appears that elicitor addition at the start of culturing inhibits the process by which dedifferentiated cells differentiate into xylem cell precursors. Elicitor addition during culturing also appears to inhibit the transition from xylem cell precursors to immature TEs, and induces xylem cell precursors or xylem parenchyma cells to produce an extracellular stress lignin-like substance.     

Elicitor mediated enhancement of wedelolactone in cell suspension culture of <Emphasis Type="Italic">Eclipta alba</Emphasis> (L.) Hassk

The present research focused on enhancing the production of wedelolactone through cell suspension culture (CSC) in Eclipta alba (L.) Hassk. With an aim of attaining a sustainable CSC, various plant growth regulators, elicitors and agitation speed were examined. Nodal segments of in vitro propagated plantlets induced the maximum percentage (93.47?±?0.61%) of callus inoculated on Murashige and Skoog (MS) medium fortified with picloram (2 mg L^?1). The growth kinetics of CSC exhibited a sigmoid pattern with a lag phase (0–6 days), a log phase (6–18 days), a stationary phase (18–24 days) and then death phase thereafter. The highest biomass accumulation in CSC with 7.09?±?0.06 g 50 mL^?1 fresh weight, 1.52?±?0.02 g 50 mL^?1 dry cell weight, 1.34?±?0.01?×?10⁶ cell mL^?1 total cell count and 57.00?±?0.58% packed cell volume was obtained in the liquid MS medium supplemented with 1.5 mg L^?1 picloram plus 0.5 mg L^?1 kinetin at 120 rpm. High performance thin layer chromatography confirmed that yeast extract (biotic elicitor) at 150 mg L^?1 accumulated more CSC biomass with 1.22-fold increase in wedelolactone (288.97?±?1.94 µg g^?1 dry weight) content in comparison to the non-elicited CSC (237.78?±?0.04 µg g^?1 dry weight) after 120 h of incubation. Contrastingly, methyl jasmonate (abiotic elicitor) did not alter the biomass but increased the wedelolactone content (259.32?±?1.06 µg g^?1 dry weight) to an extent of 1.09-fold at 100 µM. Complete plantlet regeneration from CSC was possible on MS medium containing N⁶-benzyladenine (0.75 mg L^?1) and abscisic acid (0.5 mg L^?1). Thus, the establishment of protocol for CSC constitutes the bases for future biotechnological improvement studies in this crop.     

Manipulation of culture strategies to enhance capsaicin biosynthesis in suspension and immobilized cell cultures of Capsicum chinense Jacq. cv. Naga King Chili

Manipulation of culture strategies was adopted to study the influence of nutrient stress, pH stress and precursor feeding on the biosynthesis of capsaicin in suspension and immobilized cell cultures of C. chinense. Cells cultured in the absence of one of the four nutrients (ammonium and potassium nitrate for nitrate and potassium stress, potassium dihydrogen orthophosphate for phosphorus stress, and sucrose for sugar stress) influenced the accumulation of capsaicin. Among the stress factors studied, nitrate stress showed maximal capsaicin production on day 20 (505.9 ± 2.8 μg g^?1 f.wt) in immobilized cell, whereas in suspension cultures the maximum accumulation (345.5 ± 2.9 μg g^?1 f.wt) was obtained on day 10. Different pH affected capsaicin accumulation; enhanced accumulation of capsaicin (261.6 ± 3.4 μg g^?1 f.wt) was observed in suspension cultures at pH 6 on day 15, whereas in case of immobilized cultures the highest capsaicin content (433.3 ± 3.3 μg g^?1 f.wt) was obtained at pH 5 on day 10. Addition of capsaicin precursors and intermediates significantly enhanced the biosynthesis of capsaicin, incorporation of vanillin at 100 μM in both suspension and immobilized cell cultures resulted in maximum capsaicin content with 499.1 ± 5.5 μg g^?1 f.wt on day 20 and 1,315.3 ± 10 μg g^?1 f.wt on day 10, respectively. Among the different culture strategies adopted to enhance capsaicin biosynthesis in cell cultures of C. chinense, cells fed with vanillin resulted in the maximum capsaicin accumulation. The rate of capsaicin production was significantly higher in immobilized cells as compared to freely suspended cells.     

Suppression of carbendazim-susceptible and -resistant Sclerotinia sclerotiorum with Macleya alkaloids

Macleaya alkaloids (abr. MCA), an extract from aerial parts of Macleaya cordata, was investigated on suppressing Sclerotinia stem rot disease. The median inhibitory concentrations (EC₅₀) of MCA on mycelia growth were 5.21 μg mL^?1 to carbendazim-susceptible (Ss01) and 6.34 μg mL^?1 to carbendazim-resistant (Hm25) S. sclerotiorum, and there was no cross-resistance between MCA and carbendazim. MCA blocked the mycelial membrane leakage and regulated the exo-secretion of the reducing sugar and oxalate in a concentration-dependent manner. Moreover, MCA also significantly destroyed the redox balance including superoxide dismutase, peroxidase and catalase in Sclerotinia mycelia. In pot experiments, MCA showed an excellent antifungal efficacy on protecting rapeseed leaves from the infection of Ss01 and Hm25 isolates. The results suggested a potential possibility to develop MCA as an agro-chemical to control Sclerotinia stem rot disease and manage carbendazim resistance.     

Isolation and biological activities of an endophytic Mortierella alpina strain from the Antarctic moss Schistidium antarctici

The Antarctic endophytic fungus (strain ITA1-CCMA 952) was isolated from the moss Schistidium antarctici found in Admiralty Bay, King George Island, Antarctica. Strain ITA1-CCMA 952 was assigned to the specie Mortierella alpina by phylogenetic analysis based on 18S rRNA gene sequences. This strain produces high levels of polyunsaturated fatty acids (PUFAs), including y-(gamma) linolenic acid and arachidonic acid, which when combined represents 48.3 % of the total fatty acid content. Fungal extracts demonstrated strong antioxidant activity with the EC₅₀ value of 48.7 μg mL^?1 and also a strong antibacterial activity, mainly against the following bacteria: Escherichia coli, with a MIC of 26.9 μg mL^?1 and Pseudomonas aeruginosa and Enterococcus faecalis, both with a MIC of 107 μg mL^?1. A GC–MS analysis of the chloroform fraction obtained from the crude extract revealed the presence of potential antimicrobials (Pyrrolo[1,2-a]pyrazine-1,4-dione, hexahydro-3-(2-methylpropyl) and Pyrrolo[1,2-a]pyrazine-1,4-dione, hexahydro-3-(phenylmethyl)) as the major compounds. Therefore, the M. alpina strain ITA1-CCMA 952 is a promising fungus for the biotechnological production of antibiotics, antioxidant substances and PUFAs. This study highlights the need for more research in extreme environments, such as Antarctica.     

Uptake kinetics and storage capacity of dissolved inorganic phosphorus and corresponding dissolved inorganic nitrate uptake in Saccharina latissima and Laminaria digitata (Phaeophyceae)

Uptake rates of dissolved inorganic phosphorus and dissolved inorganic nitrogen under unsaturated and saturated conditions were studied in young sporophytes of the seaweeds Saccharina latissima and Laminaria digitata (Phaeophyceae) using a “pulse‐and‐chase” assay under fully controlled laboratory conditions. In a subsequent second “pulse‐and‐chase” assay, internal storage capacity (ISC) was calculated based on V_M and the parameter for photosynthetic efficiency F_v/F_m. Sporophytes of S. latissima showed a V_S of 0.80 ± 0.03 μmol · cm^?2 · d^?1 and a V_M of 0.30 ± 0.09 μmol · cm^?2 · d^?1 for dissolved inorganic phosphate (DIP), whereas V_S for DIN was 11.26 ± 0.56 μmol · cm^?2 · d^?1 and V_M was 3.94 ± 0.67 μmol · cm^?2 · d^?1. In L. digitata, uptake kinetics for DIP and DIN were substantially lower: V_S for DIP did not exceed 0.38 ± 0.03 μmol · cm^?2 · d^?1 while V_M for DIP was 0.22 ± 0.01 μmol · cm^?2 · d^?1. V_S for DIN was 3.92 ± 0.08 μmol · cm^?2 · d^?1 and the V_M for DIN was 1.81 ± 0.38 μmol · cm^?2 · d^?1. Accordingly, S. latissima exhibited a larger ISC for DIP (27 μmol · cm^?2) than L. digitata (10 μmol · cm^?2), and was able to maintain high growth rates for a longer period under limiting DIP conditions. Our standardized data add to the physiological understanding of S. latissima and L. digitata, thus helping to identify potential locations for their cultivation. This could further contribute to the development and modification of applications in a bio‐based economy, for example, in evaluating the potential for bioremediation in integrated multitrophic aquacultures that produce biomass simultaneously for use in the food, feed, and energy industries.     

Isosmotic points and their ecological significance for juvenile Chinese sturgeon Acipenser sinensis

Serum osmolality and ion concentrations were measured in juvenile Chinese sturgeon Acipenser sinensis at different salinities to determine the isosmotic point. Isosmotic and isoionic concentrations were calculated from the regressions for serum and ambient osmolality, with Na⁺, Cl^? and K⁺ as salinities 9·19, 8·17, 7·89 and 9·70, respectively. These values were consistent with the salinity of the habitat where juvenile A. sinensis occur in the Yangtze Estuary, suggesting that an isosmotic salinity is an important factor driving their habitat choice.     

Antifouling chromanols isolated from brown alga Sargassum horneri

Biofouling in aquatic environments have a wide range of detrimental effects on man-made structures and cause economic loss. Current antifouling compounds including Diuron, dichlorofluanid, and Irgarol are toxic and can accumulate in marine environments. Thus, effective and environmentally friendly antifoulants are needed. Six structurally similar compounds were isolated from the brown alga, Sargassum horneri, based on bioactivity-guided isolation by reversed-phased liquid flash chromatography and high-performance liquid chromatography. Six chemical constituents possessing antifouling activities were identified as chromanols consisting of polyprenyl chain by nuclear magnetic resonance and mass spectroscopy. Antifouling activities of these six compounds were determined against representative fouling organisms including a hard fouling organism the mussel Mytilus edulis, a soft fouling macroalga Ulva pertusa, the biofouling diatom Navicula annexa, and the biofouling bacteria Pseudomonas aeruginosa KNP-3 and Alteromonas sp. KNS-8. The compounds could inhibit larvae settlement of mussel M. edulis with an EC₅₀ of 0.11–3.34 μg mL^?1, spore settlement of U. pertusa zoospores (EC₅₀ of 0.01–0.43 μg mL^?1), and the diatom N. annexa (EC₅₀ of 0.008–0.19 μg mL^?1). The two biofouling bacteria were sensitive to the tested compounds (minimum inhibitory concentration of 1.68–36.8 and 1.02–30.4 μg mL^?1, respectively). From toxicity tests on juvenile Sebastes schlegelii fish, brine shrimp Artemia salina, and microalga Tetraselmis suecica, S3 had the lowest LC₅₀ values of 60.2, 108, and 6.7 μg mL^?1 and exhibited no observed effect concentration at 24.5, 41.6, and 3.1 μg mL^?1 for these three tested marine organisms, respectively.     

Kinetics of the aerobic co-metabolism of 1,1-dichloroethylene by Achromobacter sp.: a novel benzene-grown culture

Batch experiments were performed for the aerobic co-metabolism of 1,1-dichloroethylene (1,1-DCE) by Achromobacter sp., identified by gene sequencing of 16S rRNA and grown on benzene. Kinetic models were employed to simulate the co-metabolic degradation of 1,1-DCE, and relevant parameters were obtained by non-linear least squares regression. Benzene at 90 mg L^?1 non-competitively inhibited degradation of 1,1-DCE (from 125 to 1,200 μg L^?1). The maximum specific utilization (k_c) rate and the half-saturation constant (K_c) for 1,1-DCE were 54 ± 0.85 μg h^?1 and 220 ± 6.8 μg L^?1, respectively; the k_b and K_b for benzene were 13 ± 0.18 mg h^?1 and 28 ± 0.42 mg L^?1, respectively. This study provides a theoretical basis to predict the natural attenuation when benzene and 1,1-DCE occur as co-contaminants.     

Antitumor and antioxidant activity of the freshwater macroalga <Emphasis Type="Italic">Cladophora surera</Emphasis>

Macroalgae are currently being explored as novel and sustainable sources of bioactive compounds for both pharmaceutical and nutraceutical applications arising from their antioxidant, anticancer, and antimicrobial activity. In the present study, the antitumoral and antioxidant activities of crude methanolic extracts of the freshwater macroalga Cladophora surera Parodi & Cáceres, harvested from Napostá Creek (Argentina), were investigated in vitro. The antioxidant activity was assessed by DPPH method and polyphenol content using Folin-Ciocalteu phenol reagent. Antitumoral activity was evaluated on the human breast adenocarcinoma cell line MCF-7 by measuring proliferation, migration, and cell adhesion. The algal extract (AE) showed a total phenol content of 1.62?±?0.17 μg GAE mg^?1 dry alga and DPPH scavenging activity of 25.03?±?1.99% (10 mg)^?1 dry alga. The trypan blue assay after 48 h of treatment indicated that the AE significantly inhibits proliferation in a dose-dependent manner (1–100 μg mL^?1), being more effective the highest dose employed, with a concomitant increment in dead cells. However, the colorimetric MTS assay only showed a significant decrease in cell viability at 100 μg mL^?1 AE. Using the wound healing assay, we demonstrated that AE inhibits cell migration. Through a cell adhesion assay, we found that AE affects considerably the cell adhesion capacity at all doses probed. Analysis of cell spreading indicated that cell morphology was also affected by AE treatment. These results indicate that C. surera could be a source of valuable bioactive compounds usable as antitumoral preventive therapy for their effects on the regulation of processes involved in metastasis in cells derived from human mammary cancer.     

Standing fine root mass and production in four Chinese subtropical forests along a succession and species diversity gradient

Background and aims

The influences of succession and species diversity on fine root production are not well known in forests. This study aimed to investigate: (i) whether fine root biomass and production increased with successional stage and increasing tree species diversity; (ii) how forest type affected seasonal variation and regrowth of fine roots.

Methods

Sequential coring and ingrowth core methods were used to measure fine root production in four Chinese subtropical forests differing in successional stages and species diversity.

Results

Fine root biomass increased from 262 g·m^?2 to 626 g·m^?2 with increasing successional stage and species diversity. A similar trend was also found for fine root production, which increased from 86 to 114 g·m^?2 yr ^?1 for Cunninghamia lanceolata plantation to 211–240 g·m^?2 yr ^?1 for Choerospondias axillaries forest when estimated with sequential coring data. Fine root production calculated using the ingrowth core data ranged from 186 g·m^?2 yr ^?1 for C. lanceolata plantation to 513 g·m^?2 yr ^?1 for Lithocarpus glaber – Cyclobalanopsis glauca forest.

Conclusions

Fine root biomass and production increased along a successional gradient and increasing tree species diversity in subtropical forests. Fine roots in forests with higher species diversity exhibited higher seasonal variation and regrowth rate.     

Circadian Phase,Sleepiness, and Light Exposure Assessment in Night Workers With and Without Shift Work Disorder

Most night workers are unable to adjust their circadian rhythms to the atypical hours of sleep and wake. Between 10% and 30% of shiftworkers report symptoms of excessive sleepiness and/or insomnia consistent with a diagnosis of shift work disorder (SWD). Difficulties in attaining appropriate shifts in circadian phase, in response to night work, may explain why some individuals develop SWD. In the present study, it was hypothesized that disturbances of sleep and wakefulness in shiftworkers are related to the degree of mismatch between their endogenous circadian rhythms and the night-work schedule of sleep during the day and wake activities at night. Five asymptomatic night workers (ANWs) (3 females; [mean?±?SD] age: 39.2?±?12.5 yrs; mean yrs on shift?=?9.3) and five night workers meeting diagnostic criteria (International Classification of Sleep Disorders [ICSD]-2) for SWD (3 females; age: 35.6?±?8.6 yrs; mean years on shift?=?8.4) participated. All participants were admitted to the sleep center at 16:00?h, where they stayed in a dim light (<10 lux) private room for the study period of 25 consecutive hours. Saliva samples for melatonin assessment were collected at 30-min intervals. Circadian phase was determined from circadian rhythms of salivary melatonin onset (dim light melatonin onset, DLMO) calculated for each individual melatonin profile. Objective sleepiness was assessed using the multiple sleep latency test (MSLT; 13 trials, 2-h intervals starting at 17:00?h). A Mann-Whitney U test was used for evaluation of differences between groups. The DLMO in ANW group was 04:42?±?3.25?h, whereas in the SWD group it was 20:42?±?2.21?h (z = 2.4; p?<?.05). Sleep did not differ between groups, except the SWD group showed an earlier bedtime on off days from work relative to that in ANW group. The MSLT corresponding to night work time (01:00–09:00?h) was significantly shorter (3.6?±?.90?min: [M?±?SEM]) in the SWD group compared with that in ANW group (6.8?±?.93?min). DLMO was significantly correlated with insomnia severity (r = ?.68; p < .03), indicating that the workers with more severe insomnia symptoms had an earlier timing of DLMO. Finally, SWD subjects were exposed to more morning light (between 05:00 and 11:00?h) as than ANW ones (798 vs. 180 lux [M?±?SD], respectively z?=??1.7; p?<?.05). These data provide evidence of an internal physiological delay of the circadian pacemaker in asymptomatic night-shift workers. In contrast, individuals with SWD maintain a circadian phase position similar to day workers, leading to a mismatch/conflict between their endogenous rhythms and their sleep-wake schedule. (Author correspondence: vgumeny1@hfhs.org)     

Sensible heat transfer and thermal windows in Dasyprocta leporina (Mammalia,Rodentia)

This study aimed to evaluate the diurnal variation of the sensible heat transfer in red-rumped agoutis (Dasyprocta leporina) bred in captivity in a semi-arid environment. In addition, we seek to identify thermal windows by infrared thermography during the daytime period (07:00, 09:00, 11:00, 14:00, and 16:00). The body surface temperature was higher in the pinna (36.84 ± 0.11 °C), followed by the hind limbs (36.55 ± 0.11 °C). These body regions were primarily responsible for heat loss by radiation (which was 10.13 ± 1.17 W m^?2 and 11.19 ± 1.17 W m^?2, respectively), and acted like biological thermal windows. Heat transfer by convection was more intense in the body trunk and hind limbs at all times of the day. Thus, sensible heat transfer is important for maintaining homeothermy in red-rumped agouti in hot environments. In conclusion, these rodents use specialized body regions (pinna and hind limbs) for heat transfer.     

Bioprospecting of brown seaweed (Ochrophyta) from the Yucatan Peninsula: cytotoxic,antiproliferative, and antiprotozoal activities

In the Yucatan Peninsula coast, a large diversity of seaweed species are found, and recent studies have reported the presence of metabolites with pharmaceutical importance. In this study, a biological screening of brown seaweed extracts from Dictyota ciliolata, Padina sanctae-crucis, Sargassum fluitans, and Turbinaria tricostata was carried out. Their cytotoxicity and antiproliferative activities were evaluated by the sulforhodamine B assay on human embryonic kidney (HEK 293), human breast cancer (MCF-7), human prostate cancer (LNCaP), and human hepatic cancer (Hep-G2) cell lines. Seaweed extracts were also tested for their anti-trichomonal (Trichomonas vaginalis) and anti-giardicidal (Giardia lamblia) properties. Fucan fractions were extracted using successive maceration with ethanol/water and freeze-dried. Organics extracts were obtained from ethanol residue from liquid–liquid fractionation. A total of four ethanol extracts, four fucan-rich fractions, four ethanolic extracts, and 12 organic fractions were obtained. Only the ethanolic extracts from Turbinaria tricostata and D. ciliolata were active against LNCaP (CC₅₀ of 24.4 and 29.3 μg mL^?1, respectively). Interestingly, the activity found in the extracts from D. ciliolata and Turbinaria tricostata was maintained when both extracts were subjected to a liquid–liquid fractionation with hexane on the LNCaP cell line (CC₅₀ of 24.4 and 25.2 μg mL^?1, respectively). The antiproliferative assays showed that both dichloromethane and ethanolic fractions from P. sanctae-crucis were active against MCF-7, with IC₅₀ of 26.1 and 29.8 μg mL^?1, respectively. These species have been selected for further bio-guided fractionation and isolation of active compounds.     

Feasibility of Using Phytoextraction to Remediate a Compost-Based Soil Contaminated with Cadmium

Greenhouse and in-situ field experiments were used to determine the potential for phytoextraction to remediate soil contaminated with Cd from municipal solid waste (MSW) and sewage sludge (SS) compost application at a Peterborough (Canada) site. For the greenhouse experiment, one native (Chenopodium album) and three naturalized (Poa compressa, Brassica juncea, Helianthus annuus) plant species were planted in soil containing no detectable Cd (<1.0 μg·g^?1), and soil from the site containing low (5.0 ± 0.3 μg·g^?1 Cd), and high (16.5 ± 1.2 μg?g^?1 Cd) Cd concentrations. Plant uptake was low (root BAFs ≤0.5) for all species except P. compressa in the low Cd treatment (BAF 1.0). Only B. juncea accumulated Cd in its shoots, though uptake was low (BAF ≤0.3). For the field experiment, B. juncea was planted in-situ in areas of low and high Cd concentrations. Brassica juncea Cd uptake was low (root and shoot BAFs <0.2) in both treatments. Sequential extraction analysis indicated that Cd is retained primarily by low bioavailability soil fractions, and phytoextraction is therefore not feasible at this site. Though low Cd bioavailability has negative implications for Cd phytoextraction from MSW/SS compost-based soils, it may limit receptor exposure to Cd sufficiently to eliminate the potential for risk at this site.     

Kocuria SM1 controls vibriosis in rainbow trout (Oncorhynchus mykiss,Walbaum)

Aims: To develop probiotics for the control of vibriosis caused by Vibrio anguillarum and Vibrio ordalii in finfish. Methods and Results: Kocuria SM1, isolated from the digestive tract of rainbow trout, was administered orally to rainbow trout (Oncorhynchus mykiss) for 2 weeks at a dose equivalent to c. 10⁸ cells per g of feed and then challenged intraperitoneally with V. anguillarum and V. ordalii. Use of SM1 led to a reduction in mortalities to 15–20% compared to 74–80% mortalities in the controls. SM1 stimulated both cellular and humoral immune responses in rainbow trout, by elevation of leucocytes (5·5 ± 0·8 × 10⁶ ml^?1 from 3·7 ± 0·8 × 10⁶ ml^?1), erythrocytes (1·2 ± 0·1 × 10⁸ ml^?1 from 0·8 ± 0·1 × 10⁸ ml^?1), protein (23 ± 4·4 mg ml^?1 from 16 ± 1·3 mg ml^?1), globulin (15·7 ± 0·2 mg ml^?1 from 9·9 ± 0·1 mg ml^?1) and albumin (7·3 ± 0·2 mg ml^?1 from 6·1 ± 0·1 mg ml^?1) levels, upregulation of respiratory burst (0·05 ± 0·01 from 0·02 ± 0·01), complement (56 ± 7·2 units ml^?1 from 40 ± 8·0 units ml^?1), lysozyme (920 ± 128·8 units ml^?1 from 760 ± 115·3 units ml^?1) and bacterial killing activities. Conclusions: Kocuria SM1 successfully controlled vibriosis in rainbow trout, and the mode of action reflected stimulation of the host innate immune system. Significance and Impact of the Study: Probiotics can contribute a significant role in fish disease control strategies, and their use may replace some of the inhibitory chemicals currently used in fish farms.     

Reduced sensitivity of tomato early blight pathogen (Alternaria solani) isolates to protectant fungicides,and implication on disease control

The sensitivity of Alternaria solani isolates to the fungicides mancozeb and chlorothalonil was evaluated, to determine if inadequate disease management by these fungicides could be attributed to reduced sensitivity of A. solani isolates to these fungicides. The sensitivity of 60 isolates of A. solani was assessed using the inhibition of radial mycelial growth (RG) method, using fungicide concentrations of 0, 1.0, 10, 100, 500 and 1000 μg a.i ml^?1 medium. EC₅₀ was calculated for each isolate and fungicide combination. The EC₅₀ values of different A. solani isolates to mancozeb ranged from 9.05 to 712.65 μg ml^?1. EC₅₀ values of different isolates to chlorothalonil ranged from 4.25 to 849.4 μg ml^?1. The percentage of isolates with reduced sensitivity was 46.7 and 53.3% for mancozeb and chlorothalonil, respectively. Results of the in vivo tests demonstrated decline in disease control by the two fungicides with the reduced-sensitivity isolates compared to the sensitive ones.