Improvement of fungal extraction of phosphorus from sewage sludge ash by Aspergillus niger using sludge filtrate as nutrient substrate.

Fungal extraction is a promising approach for reclaiming phosphorus (P) from sewage sludge ash (SSA). However, this approach faces notable technical and economic challenges, including an unknown P speciation evolution and the addition of expensive chemical organic carbon. In this study, the use of an organic-rich effluent produced in sludge dewatering as nutrient source is proposed to initiate the fungal extraction of SSA-borne P with Aspergillus niger. The changes in P speciation in the ash during fungal treatment was analyzed by combined sequential extraction, solid-state 31P nuclear magnetic resonance, and P X-ray absorption near edge spectroscopy. Results showed that after 5 days of fungal treatment using sludge-derived organics, 85 % of P was leached from SSA. Dominantly, this considerable release of P resulted from the dissolution of Ca3(PO4)2, AlPO4, FePO4, and Mg3(PO4)2 in the ash, and their individual contribution rates to P released accounted for 28.0 %, 24.3 %, 20.6 %, and 18.8 %, respectively. After removal of metal cations (e.g., Mg2+, Al3+, Fe3+, and heavy metals) by cation exchange resin (CER), a hydroxyapatite (HAP) product with a purity of > 85 % was harvested from the extract by precipitation with CaCl2. By contrast, without CER purification, a crude product of Ca/Mg-carbonates and phosphates mixture were obtained from this extract. A total of 73.2 wt% of P was ultimately recovered from SSA through integrated fungal extraction, CER purification, and HAP crystallization. These findings provide a mechanistic basis for the development of waste management strategies for improved P reclamation with minimal chemical organics consumption.

UHPLC-MS/MS method for simultaneous quantification of doripenem, meropenem, ciprofloxacin, levofloxacin, pazufloxacin, linezolid, and tedizolid in filtrate during continuous renal replacement therapy.

BACKGROUND: Since severe infections frequently cause acute kidney injury (AKI), continuous renal replacement therapy (CRRT) is often initiated for regulation of inflammatory mediators and renal support. Thus, it is necessary to decide the antibiotic dosage considering the CRRT clearance in addition to residual renal function. Some of the hemofilters used in CRRT are known to adsorb antibiotics, and clearance of antibiotics may differ depending on the adsorptive characteristics of hemofilters. Although assay systems for blood and CRRT filtrate concentrations are required, no method for measuring antibiotics concentrations in filtrate has been reported. We developed a UHPLC-MS/MS method for simultaneous quantification of antibiotics commonly used in ICU, comprising carbapenems [doripenem (DRPM) and meropenem (MEPM)], quinolones [ciprofloxacin (CPFX), levofloxacin (LVFX) and pazufloxacin (PZFX)] and anti-MRSA agents [linezolid (LZD), and tedizolid (TZD)] in CRRT filtrate samples. METHODS: Filtrate samples were pretreated by protein precipitation. The analytes were separated with an ACQUITY UHPLC CSH C18 column under a gradient mobile phase consisting of water and acetonitrile containing 0.1% formic acid and 2 mM ammonium formate. RESULTS: The method showed good linearity over wide ranges. Within-batch and batch-to-batch accuracy and precision for each drug fulfilled the criteria of the US Food and Drug Administration guidance. The recovery rate was more than 87.20%. Matrix effect ranged from 99.57% to 115.60%. Recovery rate and matrix effect did not differ remarkably between quality control samples at different concentrations. CONCLUSION: This is the first report of a simultaneous quantification method of multiple antibiotics in filtrate of CRRT circuit.

Composition, Properties, and Utilization of Fumaric Acid Sludge By-Produced from Industrial Phthalic Anhydride Wastewater Treatment.

To understand fumaric acid sludge (FAS) systematically and comprehensively and find out how to utilize it, we conducted a series of characterization analyses on FAS. Fourier transform infrared (FT-IR) Spectra shows that the main component of FAS is fumaric acids and also contains a small amount of silicate. The nuclear magnetic resonance hydrogen (1H-NMR) spectrum also shows that fumaric acid accounted for a large proportion of FAS. The X-ray diffraction (XRD) shows that the main phase in FAS is fumaric acid, and there is also a small amount of Kaliophilite. After gas chromatography and mass spectrometry (GC-MS) and pyrolysis gas chromatography and mass spectrometry (Py-GC-MS) analysis, it indicates that the possible volatiles and pyrolysis products in FAS are fumaric acid, maleic acid, maleic anhydride, phthalic acid, etc. In the test of Liquid chromatography and mass spectrometry (LC-MS), we determined the contents of phthalic acid, fumaric acid, and maleic acid in FAS. The detailed mass content of each component in FAS is as follows: phthalic acid is about 0.10-0.15%; maleic anhydride is about 0.40-0.80%; maleic acid is about 18.40-19.0%; fumaric acid is about 55.00-56.90%; succinic anhydride is about 0.06-0.08%; acrylic acid is about 0.06-0.08%; malic acid is about 0.90-1.00%; acetic acid is about 0.10-0.20%; silicate is about 0.25-0.30%; phthalic anhydride is about 0.20-0.30%; water is about 24.30-24.80%. The filtrate loss reducer (PAAF) used in oilwell drilling fluids synthesized by FAS not only has excellent temperature and complex saline resistance, the API filtration loss (FL) was only 13.2 mL/30 min in the complex saline based mud, but is also cost-effective.

In Vitro and In Vivo Inhibitory Activities of Selected Traditional Medicinal Plants against Toxin-Induced Cyto- and Entero- Toxicities in Cholera.

Careya arborea, Punica granatum, Psidium guajava, Holarrhena antidysenterica, Aegle marmelos, and Piper longum are commonly used traditional medicines against diarrhoeal diseases in India. This study investigated the inhibitory activity of these plants against cytotoxicity and enterotoxicity induced by toxins secreted by Vibrio cholerae. Cholera toxin (CT) and non-membrane damaging cytotoxin (NMDCY) in cell free culture filtrate (CFCF) of V. cholerae were quantified using GM1 ELISA and cell-based assays, respectively. Hydro-alcoholic extracts of these plants and lyophilized juice of P. granatum were tested against CT-induced elevation of cAMP levels in CHO cell line, binding of CT to ganglioside GM1 receptor and NMDCY-induced cytotoxicity. Significant reduction of cAMP levels in CFCF treated CHO cell line was observed for all extracts except P. longum. C. arborea, P. granatum, H. antidysenterica and A. marmelos showed >50% binding inhibition of CT to GM1 receptor. C. arborea, P. granatum, and P. guajava effectively decreased cytotoxicity and morphological alterations caused by NMDCY in CHO cell line. Further, the efficacy of these three plants against CFCF-induced enterotoxicity was seen in adult mice ligated-ileal loop model as evidenced by decrease in volume of fluid accumulation, cAMP levels in ligated-ileal tissues, and histopathological changes in intestinal mucosa. Therefore, these plants can be further validated for their clinical use against cholera.

Gut microbiota from green tea polyphenol-dosed mice improves intestinal epithelial homeostasis and ameliorates experimental colitis.

BACKGROUND: Alteration of the gut microbiota may contribute to the development of inflammatory bowel disease (IBD). Epigallocatechin-3-gallate (EGCG), a major bioactive constituent of green tea, is known to be beneficial in IBD alleviation. However, it is unclear whether the gut microbiota exerts an effect when EGCG attenuates IBD. RESULTS: We first explored the effect of oral or rectal EGCG delivery on the DSS-induced murine colitis. Our results revealed that anti-inflammatory effect and colonic barrier integrity were enhanced by oral, but not rectal, EGCG. We observed a distinct EGCG-mediated alteration in the gut microbiome by increasing Akkermansia abundance and butyrate production. Next, we demonstrated that the EGCG pre-supplementation induced similar beneficial outcomes to oral EGCG administration. Prophylactic EGCG attenuated colitis and significantly enriched short-chain fatty acids (SCFAs)-producing bacteria such as Akkermansia and SCFAs production in DSS-induced mice. To validate these discoveries, we performed fecal microbiota transplantation (FMT) and sterile fecal filtrate (SFF) to inoculate DSS-treated mice. Microbiota from EGCG-dosed mice alleviated the colitis over microbiota from control mice and SFF shown by superiorly anti-inflammatory effect and colonic barrier integrity, and also enriched bacteria such as Akkermansia and SCFAs. Collectively, the attenuation of colitis by oral EGCG suggests an intimate involvement of SCFAs-producing bacteria Akkermansia, and SCFAs, which was further demonstrated by prophylaxis and FMT. CONCLUSIONS: This study provides the first data indicating that oral EGCG ameliorated the colonic inflammation in a gut microbiota-dependent manner. Our findings provide novel insights into EGCG-mediated remission of IBD and EGCG as a potential modulator for gut microbiota to prevent and treat IBD. Video Abstract.

Ameliorated Antibacterial and Antioxidant Properties by Trichoderma harzianum Mediated Green Synthesis of Silver Nanoparticles.

Biosynthesis of silver nanoparticles using beneficial Trichoderma harzianum is a simple, eco-friendly and cost-effective route. Secondary metabolites secreted by T. harzianum act as capping and reducing agents that can offer constancy and can contribute to biological activity. The present study aimed to synthesize silver nanoparticles using T. harzianum cell filtrate and investigate different bioactive metabolites based on LC-MS/MS analysis. The synthesized silver nanoparticles (AgNPs) from T. harzianum were characterized by ultraviolet-visible spectrophotometry, Fourier transform infrared spectrometry (FT-IR), energy-dispersive spectroscopy (EDS), dynamic light scattering (DLS), X-ray powder diffraction (XRD) and scanning electron microscopy (SEM). The surface plasmon resonance of synthesized particles formed a peak centered near 438 nm. The DLS study determined the average size of AgNPs to be 21.49 nm. The average size of AgNPs was measured to be 72 nm by SEM. The cubic crystal structure from XRD analysis confirmed the synthesized particles as silver nanoparticles. The AgNPs exhibited remarkable antioxidant properties, as determined by DPPH and ferric reducing antioxidant power (FRAP) assay. The AgNPs also exhibited broad-spectrum antibacterial activity against two Gram-positive bacteria (S. aureus and B. subtilis) and two Gram-negative bacteria (E. coli and R. solanacearum). The minimum inhibitory concentration (MIC) of AgNPs towards bacterial growth was evaluated. The antibacterial activity of AgNPs was further confirmed by fluorescence microscopy and SEM analysis.

Impacts of operating conditions on efficiency of electrokinetically enhanced filtration for de-watering of orange juice and malt extract.

The effects of operational factors an on an electrokinetic-enhanced filtration (EKEF) application to dewater orange juice (OJ) and malt extract (ME) was investigated. EKEF improved dewatering of both foodstuffs and resulted in net dewatering efficiencies of 7.4% and 4.9% for OJ and 10.7% and 6.3% for ME after 5.5 h processing under 30 V and 15 V, respectively. Dry matter content was increased by 19.2% and 15.6% for OJ after 5.5 h and 14.8% and 12.8% for ME after 3.5 h under 30 V and 15 V, respectively, compared with 14.9% and 10.3% under the control conditions for OJ and ME, respectively. The EKEF process effectively improved dewatering of high moisture-content foods with positive impacts on process efficiency by increased voltage, pressure, and the pore size of filters. The initial distance between electrodes had a negative impact as the distance increased. EKEF is a useful adjunct to improve high pressure filtration of foodstuffs.

Composition of "gold juice" using an ancient method based on intestinal microecology.

OBJECTIVE: To identify potentially effective bacterial components of gold juice, a traditional Chinese medicine treatment used for fecal microbiota transplantation. METHODS: Fecal samples were collected from five healthy children (two boys and three girls; mean age, 7.52 ± 2.31 years). The children had no history of antibiotic use or intestinal microecological preparation in the preceding 3 months. Fresh fecal samples were collected from children to prepare gold juice in mid-to-late November, in accordance with traditional Chinese medicine methods, then used within 7 days. Finally, 16S rDNA sequence analysis was used to identify potentially effective bacterial components of gold juice. QIIME software was used for comparisons of microbial species among gold juice, diluent, filtrate, and loess samples. RESULTS: Microflora of gold juice exhibited considerable changes following "ancient method" processing. Microbial components significantly differed between gold juice and filtrate samples. The gold juice analyzed in our study consisted of microbes that synthesize carbohydrates and amino acids by degrading substances, whereas the filtrate contained probiotic flora, Bacteroides, and Prevotella 9. CONCLUSIONS: This study of microbial components in gold juice and filtrate provided evidence regarding effective bacterial components in gold juice, which may aid in clinical decisions concerning fecal microbiota transplantation.

Escherichia coli Culture Filtrate Enhances the Growth of Gemmata spp.

BACKGROUND: Planctomycetes bacteria are known to be difficult to isolate, we hypothesized this may be due to missing iron compounds known to be important for other bacteria. We tested the growth-enhancement effect of complementing two standard media with Escherichia coli culture filtrate on two cultured strains of Gemmata spp. Also, the acquisition of iron by Gemmata spp. was evaluated by measuring various molecules involved in iron metabolism. MATERIALS AND METHODS: Gemmata obscuriglobus and Gemmata massiliana were cultured in Caulobacter and Staley's medium supplemented or not with E. coli culture filtrate, likely containing siderophores and extracellular ferrireductases. We performed iron metabolism studies with FeSO4, FeCl3 and deferoxamine in the cultures with the E. coli filtrate and the controls. RESULTS AND DISCUSSION: The numbers of G. obscuriglobus and G. massiliana colonies on Caulobacter medium or Staley's medium supplemented with E. coli culture filtrate were significantly higher than those on the standard medium (p < 0.0001). Agar plate assays revealed that the Gemmata colonies near E. coli colonies were larger than the more distant colonies, suggesting the diffusion of unknown growth promoting molecules. The inclusion of 10-4 to 10-3 M FeSO4 resulted in rapid Gemmata spp. growth (4-5 days compared with 8-9 days for the controls), suggesting that both species can utilize FeSO4 to boost their growth. In contrast, deferoxamine slowed down and prevented Gemmata spp. growth. Further studies revealed that the complementation of Caulobacter medium with E. coli culture filtrate and 10-4 M FeSO4 exerted a significant growth-enhancement effect compared with that obtained with Caulobacter medium supplemented with E. coli culture filtrate alone (p < 0.0122). Moreover, the intracellular iron concentrations in G. obscuriglobus and G. massiliana cultures in iron-depleted broth supplemented with the E. coli filtrate were 0.63 ± 0.16 and 0.78 ± 0.12 µmol/L, respectively, whereas concentrations of 1.72 ± 0.13 and 1.56± 0.11 µmol/L were found in the G. obscuriglobus and G. massiliana cultures grown in broth supplemented with the E. coli filtrate and FeSO4. The data reported here indicated that both E. coli culture filtrate and FeSO4 act as growth factors for Gemmata spp. via a potentiation mechanism.

Potential applications of cyanobacteria: Spirulina platensis filtrates and homogenates in agriculture.

In the present paper, products obtained from a blue-green microalga Spirulina platensis filtrate (applied for seed soaking and for foliar spray) and homogenate (used for seed coating) were tested in the cultivation of radish. Their effect on length, wet mass, multielemental composition and the greenness index of the radish leaves was examined. Multi-elemental analyses of the algal products, and radish were also performed using inductively coupled plasma-optical emission spectrometry (ICP-OES). The best soaking time, concentrations of filtrate and doses of homogenate were established. The longest and heaviest plants were observed for homogenate applied at a dose of 300 µL per 1.5 g of seeds and 15% of filtrate applied as foliar spray. The highest chlorophyll content was found in the group treated with 100 µL of homogenate and 5% of filtrate. In the case of soaking time, the longest plants were in the group where seeds were soaked for 6 h, but the heaviest and greenest were after soaking for 48 h. The applied algal products increased the content of elements in seedlings. Obtained results proved that algal extracts have high potential to be applied in modern horticulture and agriculture. The use of Spirulina-based products is consistent with the idea of sustainable agriculture that could help to ensure production of sufficient human food to meet the needs of rising population and protection of the environment.

Comparison of HCl and H2SO4 for the acid activation of a cameroonian smectite soil clay: palm oil discolouration and landfill leachate treatment.

Vertisols occupy approximately 1,200,000 ha in Northern Cameroon. Their richness in smectites allows for the production of "bleaching earths" necessary for refining palm oil, and their effluent is used for leachate treatment. In the present work, two mineral acids (HCl and H2SO4) were compared, and the most efficient acid with the lowest cost was determined for use in industrial applications. Under similar experimental conditions (ratio of acid solution/clay mass = 5/1, temperature = 97 °C, stirring time = 4 h), the quantity of cations (Fe2+, Fe3+, Al3+) solubilised during acid activation, palm oil discolouration rate by each activated sample and the financial cost of 5 L of acid solution that is required for the acid activation of one kilogram of smectite clay were compared. It was found that 2N H2SO4 was more efficient than 1N HCl and 1N H2SO4, considering palm oil bleaching efficiency and cost. The filtrate collected after the acid activation of vertisols was rich in H+ (2.04.10-1M), Fe2+ (2.8.10-3M), Fe3+ (4.2.10-2M) and Al3+ (9.2.10-2M) ions. One gram of smectite clay material produced 9 mL of this filtrate that was used for the treatment of leachate from a controlled landfill. The leachate colour decreased from 4262 to 285 PtCo units, while the corresponding chemical oxygen demand (COD) decreased from 802 to 128 mg/L. Thus, the most effective acid for industrial bleaching earth production from vertisol is 2N H2SO4 acid.

Biomedical application of greenly synthesized silver nanoparticles using the filtrate of Trichoderma viride: Anticancer and immunomodulatory potentials.

BACKGROUND: Green route biosynthesis of silver nanoparticles using Trichoderma viride (T. viride) filtrate (TVFSNPs) can serve as an alternative to antibiotics and as an effective drug delivery to combat cancer and act as an immune-stimulator. OBJECTIVES: To biosynthesize silver nanoparticles (SNPs) with T. viride filtrate using green route and to characterize and determine the cytotoxic and immunomodulatory potential of nanoparticles. MATERIAL AND METHODS: Trichoderma viride filtrate was used for biosynthesizing SNPs. The biosynthesized SNPs were characterized using UV-visible spectroscopy, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and energy dispersive X-ray (EDX). The cytotoxic properties against Hep­2C and rotavirus and the immunomodulatory potential were evaluated. RESULTS: Trichoderma viride filtrate was able to bio-reduce AgNO3 to SNPs. The surface plasmon resonance peak was at 450 nm. The presence of aldehydes, amino acids, ethers, esters, carboxylic acids, hydroxyl groups, and phenol among others indicates the capping and stabilization of proteins in the nanoparticles. The nanoparticles were spherical with a size of 0.1-10.0 nm. The EDX analysis revealed a strong signal of silver (Ag). The TVFSNPs had a cytotoxic effect on Hep2C and rotavirus in a dose-dependent manner and increased the production of immunoglobulin (Ig) A (IgA) and IgM. CONCLUSIONS: Trichoderma viride filtrate contained some biochemicals that can bio-reduce silver nitrate (AgNO3) for SNPs biosynthesis. The anticancer and immunostimulatory potential justifies the biomedical application and biotechnological relevance of T. viride.

Influence of Cdx2 and TaqI Gene Variants on Vitamin D3 Modulated Intracellular Chemokine Positive T-Cell Subsets in Pulmonary Tuberculosis.

PURPOSE: We studied the effect of 1,25(OH)2D3 (vitamin D3) on intracellular chemokine-positive T-cell subsets in whole blood cultures of healthy controls and patients with pulmonary tuberculosis. METHODS: Genotyping was performed by the polymerase chain reaction-restriction fragment length polymorphism method. The regulatory role of the Cdx2 and 3'UTR TaqI gene variants on chemokine-positive T-cell subsets was studied from culture filtrate antigen stimulated with or without vitamin D3 treated whole blood cultures of 60 healthy controls and 50 patients with pulmonary tuberculosis. FINDINGS: Vitamin D3 significantly suppressed monocyte chemoattractant protein 1, macrophage inhibitory protein (MIP)-1α, MIP-1ß, regulated on activation, normal T-cell expressed and secreted (RANTES), and interferon-γ inducible protein 10 (IP-10)-positive T-cell subsets compared with culture filtrate antigen stimulated cells without vitamin D3 treatment. In the Cdx2 AA genotype, vitamin D3 decreased MIP-1α, MIP-1ß, and RANTES-positive T cells compared with the GG genotype. Whereas in the TaqI tt genotype, decreased MIP-1ß and RANTES and increased IP-10-positive T cells were observed compared with the TT genotype in vitamin D3 treated cells (p < 0.05). IMPLICATIONS: This study suggests that vitamin D3 may regulate the chemokine-positive T cells through the Cdx2 AA and TaqI tt genotypes. This could be helpful to regulate chemokine-mediated inflammatory response during active disease condition. Hence, vitamin D3 supplementation along with tuberculosis drugs may be useful for faster recovery from the disease.

Endophytic fungi associated with Monarda citriodora, an aromatic and medicinal plant and their biocontrol potential.

CONTEXT: The Food and Agriculture Organization has estimated that every year considerable losses of the food crops occur due to plant diseases. Although fungicides are extensively used for management of plant diseases, they are expensive and hazardous to the environment and human health. Alternatively, biological control is the safe way to overcome the effects of plant diseases and to sustain agriculture. Since Monarda citriodora Cerv. ex Lag. (Lamiaceae/Labiatae) is known for its antifungal properties, it was chosen for the study. OBJECTIVE: The isolation of endophytic fungi from M. citriodora and assessing their biocontrol potential. MATERIAL AND METHODS: The isolated endophytes were characterized using ITS-5.8 S rDNA sequencing. Their biocontrol potential was assessed using different antagonistic assays against major plant pathogens. RESULTS: Twenty-eight endophytes representing 11 genera were isolated, of which, around 82% endophytes showed biocontrol potential against plant pathogens. MC-2 L (Fusarium oxysporum), MC-14 F (F. oxysporum), MC-22 F (F. oxysporum) and MC-25 F (F. redolens) displayed significant antagonistic activity against all the tested pathogens. Interestingly, MC-10 L (Muscodor yucatanensis) completely inhibited the growth of Sclerotinia sp., Colletotrichum capsici, Aspergillus flavus and A. fumigatus in dual culture assay, whereas MC-8 L (A. oryzae) and MC-9 L (Penicillium commune) completely inhibited the growth of the Sclerotinia sp. in fumigation assay. CONCLUSIONS: Endophytes MC-2 L, MC-14 F, MC-22 F and MC-25 F could effectively be used to control broad range of phytopathogens, while MC-10 L, MC-8 L and MC-9 L could be used to control specific pathogens. Secondly, endophytes showing varying degrees of antagonism in different assays represented the chemo-diversity not only as promising biocontrol agents but also as a resource of defensive and bioactive metabolites.

The stability of aerobic granular sludge treating municipal sludge deep dewatering filtrate in a bench scale sequencing batch reactor.

Inoculated with mature aerobic granular sludge in a sequencing batch reactor, gradually increasing the proportion of municipal sludge deep dewatering filtrate in influent, aerobic granular sludge was domesticated after 84 days and maintained its structure during the operation. The domesticated AGS was yellowish-brown, dense and irregular spherical shape, average size was 1.49 mm, water content and specific density were 98.13% and 1.0114, the SVI and settling velocity were 40 ml/g and 46.5m/h. After 38 days, NO3(-)-N accumulated obviously in the reactor as lack of carbon sources. When adding 1-3g solid CH3COONa at 4.5 and 5.5h of each cycle from the 57th day, the removal rate of TN rose to above 90% after 20 days, where effective COD removal and denitrification were realized in a single bioreactor. Finally, the removal rates of COD, TP, TN and NH4(+)-N were higher than 95%, 88%, 96% and 99%.

Interspecific somatic hybrids Solanum villosum (+) S. tuberosum, resistant to Phytophthora infestans.

The interspecific somatic hybrids 4x S. villosum (+) 2x S. tuberosum clone DG 81-68 (VT hybrids) were obtained and characterized molecularly and cytogenetically. The morphology of fusion-derived plants was intermediate in relation to the parental species. The expected ploidy level of the regenerants was 6x for the VT hybrids, but the real ploidy of the hybrids varied, with some of them being euploids, and others - aneuploids. The hybridity of the regenerants was verified by random amplified polymorphic DNA (RAPD) analysis. Despite the variation in ploidy, the RAPD patterns of the hybrids were mostly uniform, suggesting similarity of the genotypes of the VT clones. Genomic in situ hybridization (GISH) analysis discriminated between the chromosomes of both parental genomes in VT somatic hybrids and also confirmed their hybridity. The resistance of VT somatic hybrids to Phytophthora infestans was evaluated and all of the hybrids proved to be highly resistant. In search of the mechanisms involved in resistance of the Solanum species to P. infestans, the biochemical reactions occurring early after elicitor treatment were studied. The production of reactive oxygen species (ROS), as one of the earliest reactions induced by pathogens or their elicitors, was examined in the resistant wild species S. villosum, susceptible S. tuberosum clone DG 81-68 and in the VT hybrid, resistant to P. infestans. After treatment of the leaves with elicitor, the relative increase in ROS production was higher in leaves of the susceptible potato clone than in the resistant plants of S. villosum and the somatic hybrid.

Biological Control of Aphid Using Fungal Culture and Culture Filtrates of Beauveria bassiana

Aphids are one of the most destructive pests in crop production such as pepper, cucumber, and eggplants. The importance of entomopathogenic fungi as alternative pest control agents is increasing. Conidia of entomopathogenic fungi are influenced by environmental conditions, such as temperature and relative humidity, and cause slow and fluctuating mortality. These factors have prevented wider application and use of biocontrol agents. For investigation of means of mitigation of such problems, we conducted bioassays with 47 fungal culture filtrates in order to evaluate the potential of secondary metabolites produced by entomopathogenic fungi for use in aphid control. Among 47 culture filtrates cultured potato dextrose broth, filtrate of Beauveria bassiana Bb08 showed the highest mortality (78%) against green peach aphid three days after treatments. Filtrate of Bb08 cultured in Adamek's medium showed higher toxicity as 100% to third instar nymphs of the aphid compared with seven other filtrates cultured in different broths amended with colloidal chitin or oil. The culture filtrates and fungal cultures from media amended with colloidal chitin or oil had lower control efficacies than filtrates without these additives in three different media. These results indicate that the fungal culture fluid or culture filtrate of B. bassiana Bb08 cultured in Adamek's medium has potential for development as a mycopesticide for aphid control.