Pleurotus ostreatus `Florida' was grown in submerged liquid culture. The biomass yield of the... more Pleurotus ostreatus `Florida' was grown in submerged liquid culture. The biomass yield of the fungus, grown for 3 days in 2-liter fermentors, where the mycelial pellets measuring 5 mm in diameter were formed, was 11.7 g (dry weight)/liter. Comparing the chemical constituents of fruiting bodies produced on cotton straw and mycelial pellets revealed several similarities in total nitrogen, protein, glycogen, fatty acids, RNA, and ash content. Differences were observed in the contents of six amino acids. Although the total fatty acid content was similar, there were more saturated fatty acids in the mycelium. Cell wall composition, typical for basidiomycetes, was observed in both mycelium and fruiting bodies, with laminarin as the main polymer.
Beneficial Co-Utilization of Agricultural, Municipal and Industrial by-Products, 1998
The objectives of this study were to determine the level of suppressiveness of composted municipa... more The objectives of this study were to determine the level of suppressiveness of composted municipal solid waste (CMSW) against soil-borne plant pathogens, and to investigate the mechanism involved in this process. The suppressiveness of CMSW to Rhizoctonia solani and Fusarium oxysporum f.sp. vasinfectum was studied in greenhouse experiments using sandy soil amended with different levels of CMSW. R. solani and F. oxysporum f.sp. vasinfectum disease severity in cotton plants was reduced in the presence of mature compost by 80 and 95%, respectively. After 1.5 months of composting, CMSW still did not suppress R. solani, whereas 2 week-old compost already exhibited suppression of F. oxysporum f.sp. vasinfectum. Reducing the microbial population of CMSW by autoclaving, gamma-irradiation or heat treatment negated R. solani suppression. Thus, we suggest that the mechanism involved in the observed suppression is biological. This hypothesis is supported by the fact that the addition of 5% CMSW to heat-treated CMSW resulted in recolonization of antagonistic microorganisms and restored the compost’s suppressive ability. On the other hand, heat treatment of CMSW did not eliminate its ability to suppress F. oxysporum f.sp. vasinfectum. The mechanism governing the suppression of R. solani is suggested to involve lysis of fungal hyphae, mostly by the bacterial population, as observed by microscopic examination. Some bacteria isolated from the CMSW showed chitin-degradation ability and the capacity to inhibit R. solani growth. One of these isolates, which suppressed R. solani in cotton plants in greenhouse experiments, was identified as Enterobacter agglomerans. Inoculation of heated compost with Trichoderma harzianum suppressed R. solani significantly. However, the addition of T harzianum did not improve the suppressive ability of the mature compost, despite the fact that this compost was successfully colonized.
The lignin peroxidase (LIP) isozyme profile of the white-rot fungus Phanerochaete chrysosporium c... more The lignin peroxidase (LIP) isozyme profile of the white-rot fungus Phanerochaete chrysosporium changes markedly with culture age. This change occurs extracellularly and results from enzymatic dephosphorylation of LIP isozymes. In this study, a novel mannose 6-phosphatase (M6Pase) from extracellular culture fluid filtrate of P. chrysosporium, shown to be responsible for the extracellular postranslational modification of LIP, was purified and characterized. In vitro incubation of the purified M6Pase with purified LIP isozyme H2 resulted in its conversion to isozyme H1, with an equimolar release of orthophosphate. Using different sugar phosphates as substrate, the enzyme exhibited narrow specificity, showing activity mostly for mannose 6-phosphate (K m ؍ 0.483 mM). The enzyme displayed a molecular mass of 82 kDa, as determined by gel filtration, and 40.4 and 39.1 kDa, on SDS-PAGE, suggesting that the native form is a dimer. The N-terminal sequence of the enzyme has no homology with that of other reported phosphatases. M6Pase is a metaloprotein with manganese and cobalt as the preferred metal ions. It is N-glycosylated proteins with an isoelectric point of 4.7-4.8 and a pH optimum of 5. Based on its characteristics, M6Pase from P. chrysosporium seems to be a unique phosphatase responsible for posttranslation modification of LIP isozymes.
Both quality and quantity of organic matter (OM) in soils affect plant growth and health. Crop re... more Both quality and quantity of organic matter (OM) in soils affect plant growth and health. Crop residues and root exudates affect the activity of beneficial microorganisms, as well as pathogens (Chang et al, 1986). The effects of OM decomposition level in the soil on interactions of beneficial microorganisms and pathogens, and on plant growth have been largely overlooked (Grebus et al, 1994; Hoitink and Fahy, 1986). Both the mineral fraction and the yearly introduced organic residues, as well as their resulting transformations in soils, play a role in this complex. In addition, humic substances (HS), the most stable organic components in soil, may have both direct and indirect effects on plant growth (Chen and Aviad, 1990; Chen et al, 1994; Stevenson, 1985).
Page 1. Does organic farming increase soil suppression against Fusarium wilt of melon? Anat Yogev... more Page 1. Does organic farming increase soil suppression against Fusarium wilt of melon? Anat Yogev & Yael Laor & Jaacov Katan & Yitzhak Hadar & Rony Cohen & Shlomit Medina & Michael Raviv Received: 12 January 2011 ...
... M. Shenker and Y. Chen, Dep. of Soil and Water Sciences, Faculty of Agriculture, The Hebrew U... more ... M. Shenker and Y. Chen, Dep. of Soil and Water Sciences, Faculty of Agriculture, The Hebrew University of Jerusalem, PO Box 12, Rehovot, Israel; and Y. Hadar, Dep. ... The index (ofit) for the weighted sum of the squares of the p[H] deviation is given by - p[H]caicuiated)2 [4] ...
... 12 Compost Microbial Populations and Interactions with Plants Dror Minz, Stefan J. Green, May... more ... 12 Compost Microbial Populations and Interactions with Plants Dror Minz, Stefan J. Green, Maya Ofek, and ... TY, Stone AG, Kraakman B, Iannotti DA, Wilson GE, Madden LV, Hoitink HAJ (1997) Cross ... Ecol 35: 207216 DeSantis TZ Jr, Hugenholtz P, Keller K, Brodie EL, Larsen N ...
The stability constants of the fluorescent siderophore pseudobactin St3 (PSB 3) produced by Pseud... more The stability constants of the fluorescent siderophore pseudobactin St3 (PSB 3) produced by Pseudomonas putida strain 3 with Fe 3 , Cu 2+ , Mn 2+ , Zn 2+ , and Fe 2 * were determined using fluorescence spectroscopy and potentiometric titrations. Stability constants for PSB 3 , with Fe'*, Fe 2 *, Mn 2+ , and Zn 2+ were determined based on titration to saturation of a PSB 3 ligand solution with either of the metals, then back-titrating the solution with an EDTA solution along with simultaneous measurements of fluorescence and visible spectra. A nonlinear curve fitting between the fluorescence intensity (Y) and the concentration (C) of the metal or EDTA was used for the determination of the concentrations of the free and complexed ligands. The overall stability constant (log XML) obtained for Fe 3+ by this method was the same as that obtained by visible spectrosopy.The log AML values obtained by fluorescence spectroscopy for Mn 2+ and Zn 2+ (17.5 and 19.4, respectively) were in good agreement with log Km, values obtained by potentiometric titration (17.3 and 19.8, respectively). It was found that two chromatography bands obtained from PSB 3 solutions isolated and purified from cultures grown under different conditions cbelated Fe 3 + with practically the same affinity. The log Km. of PSB 3 with Fe 3+ , Zn 2+ , Cu 2+ , Mn 2+ , and Fe 2 * were calculated using the protonation constants determined by potentiometry (pA.i = 11.28, plfo = 7.74, pAi, = 5.35) and were found to be 29
Composting is a partially controlled bio-oxidative process through which highly heterogeneous org... more Composting is a partially controlled bio-oxidative process through which highly heterogeneous organic matter (OM) in its solid-state transforms into a humified material. The variability of the OM undergoing composting makes compost research a great challenge. Our purpose was to define chemical and plant response characteristics of a variety of composts, grouped based on their major source materials. Thirty-seven commercial composts
13C NMR spectra acquired with Cross-Polarization Magic Angle Spinning (CPMAS) were used to study ... more 13C NMR spectra acquired with Cross-Polarization Magic Angle Spinning (CPMAS) were used to study solid and finely ground samples of decomposing organic matter. Compost prepared from separated cattle manure (CSM-the solid fraction obtained by centrifugal separators from a slurry of cattle manure) at the start and maturity stages of the composting process was investigated. CPMAS I~C NMR spectra exhibited an increase in aromaticity and carboxyl groups content and a decrease in carbohydrates during composting. The CPMAS 13C NMR measurements agreed with those of crude fiber analyses. Cation exchange capacity increased from 62.8 to 180.9 meq/100g 014, while the C/N ratio decreased from 27.2 to 8.7 along the composting process. The procedure proposed to conduct CPMAS 13C NMR and FTIR measurements directly on ground decomposing organic matter without the application of extractions was shown to provide useful information on the decomposition process.
Rhizonus arrhizus was found to produce a novel siderophore named raphorin (Ra) when grown under F... more Rhizonus arrhizus was found to produce a novel siderophore named raphorin (Ra) when grown under Fe deficiency. Partially purified Fe‐Ra was found to alleviate Fe deficiency when applied to tomato plants grown in nutrient solutions buffered by either CaCO3 (pH 7.3) or HEPES (pH 7). Iron (Fe) uptake rate by plants mediated by Ra, and translocation rate to the shoot,
The geographical distribution and ecological habitats of the Pleurotus eryngii complex in Israel ... more The geographical distribution and ecological habitats of the Pleurotus eryngii complex in Israel are described from a study of 60 genotypes from 10 populations. Both MEA and PDA media were suitable for growth of all genotypes at all temperatures tested (4-37 mC). There was a high correlation between a coefficient of growth and the mean colony diameter growth rate. All genotypes reached the maximum growth at 27 m. Growth rate at 30 m was greater than at 19 m. We found highly significant (P 0n0001) variability among growth rates of Israeli genotypes, indicating ecogeographical differences among populations. The growth rate of 12 European genotypes from the Ukraine and Slovakia was higher than most of the Israeli genotypes when grown at 27 m (nonstress conditions), but Israeli genotypes tolerated 37 m (stress conditions) better, and recovered faster than European populations when returned to 27 m. We conclude that Israeli genotypes are better adapted to hot and dry climates than European genotypes. Based on multiple regression analyses, strong correlations were found between relative humidity and rainfall parameters, but not temperature, of the locations from which Israeli isolates were collected, and their growth rates. This indicates that, paradoxically, relative humidity and rainfall have a stronger effect than temperature on the adaptability of this complex to different environments.
The measurement of growth rate of three isolates-P14, P15 and P19 (obtained after regeneration of... more The measurement of growth rate of three isolates-P14, P15 and P19 (obtained after regeneration of protoplasts of the control strain) with significantly higher (PI 4, P19) or lower (PI 5) activity of laccase than the control strain (P. ostreatus florida F6) revealed similar patterns for P14 and P19; PI5 had a higher growth rate and the highest rate was observed in the control strain. The rate of mineralization of 14C-lignin on SSF (perlite) by strains F6 and PI5 was almost the same and it was higher than that of P14 and P 19 strains. The enzyme pattern of the individual isolates, studied by gel electrophoresis and activity staining of laccase, did not show any difference in isozyme patterns of the isolates, but there were differences in the level of gene expression.
Pleurotus ostreatus `Florida' was grown in submerged liquid culture. The biomass yield of the... more Pleurotus ostreatus `Florida' was grown in submerged liquid culture. The biomass yield of the fungus, grown for 3 days in 2-liter fermentors, where the mycelial pellets measuring 5 mm in diameter were formed, was 11.7 g (dry weight)/liter. Comparing the chemical constituents of fruiting bodies produced on cotton straw and mycelial pellets revealed several similarities in total nitrogen, protein, glycogen, fatty acids, RNA, and ash content. Differences were observed in the contents of six amino acids. Although the total fatty acid content was similar, there were more saturated fatty acids in the mycelium. Cell wall composition, typical for basidiomycetes, was observed in both mycelium and fruiting bodies, with laminarin as the main polymer.
Beneficial Co-Utilization of Agricultural, Municipal and Industrial by-Products, 1998
The objectives of this study were to determine the level of suppressiveness of composted municipa... more The objectives of this study were to determine the level of suppressiveness of composted municipal solid waste (CMSW) against soil-borne plant pathogens, and to investigate the mechanism involved in this process. The suppressiveness of CMSW to Rhizoctonia solani and Fusarium oxysporum f.sp. vasinfectum was studied in greenhouse experiments using sandy soil amended with different levels of CMSW. R. solani and F. oxysporum f.sp. vasinfectum disease severity in cotton plants was reduced in the presence of mature compost by 80 and 95%, respectively. After 1.5 months of composting, CMSW still did not suppress R. solani, whereas 2 week-old compost already exhibited suppression of F. oxysporum f.sp. vasinfectum. Reducing the microbial population of CMSW by autoclaving, gamma-irradiation or heat treatment negated R. solani suppression. Thus, we suggest that the mechanism involved in the observed suppression is biological. This hypothesis is supported by the fact that the addition of 5% CMSW to heat-treated CMSW resulted in recolonization of antagonistic microorganisms and restored the compost’s suppressive ability. On the other hand, heat treatment of CMSW did not eliminate its ability to suppress F. oxysporum f.sp. vasinfectum. The mechanism governing the suppression of R. solani is suggested to involve lysis of fungal hyphae, mostly by the bacterial population, as observed by microscopic examination. Some bacteria isolated from the CMSW showed chitin-degradation ability and the capacity to inhibit R. solani growth. One of these isolates, which suppressed R. solani in cotton plants in greenhouse experiments, was identified as Enterobacter agglomerans. Inoculation of heated compost with Trichoderma harzianum suppressed R. solani significantly. However, the addition of T harzianum did not improve the suppressive ability of the mature compost, despite the fact that this compost was successfully colonized.
The lignin peroxidase (LIP) isozyme profile of the white-rot fungus Phanerochaete chrysosporium c... more The lignin peroxidase (LIP) isozyme profile of the white-rot fungus Phanerochaete chrysosporium changes markedly with culture age. This change occurs extracellularly and results from enzymatic dephosphorylation of LIP isozymes. In this study, a novel mannose 6-phosphatase (M6Pase) from extracellular culture fluid filtrate of P. chrysosporium, shown to be responsible for the extracellular postranslational modification of LIP, was purified and characterized. In vitro incubation of the purified M6Pase with purified LIP isozyme H2 resulted in its conversion to isozyme H1, with an equimolar release of orthophosphate. Using different sugar phosphates as substrate, the enzyme exhibited narrow specificity, showing activity mostly for mannose 6-phosphate (K m ؍ 0.483 mM). The enzyme displayed a molecular mass of 82 kDa, as determined by gel filtration, and 40.4 and 39.1 kDa, on SDS-PAGE, suggesting that the native form is a dimer. The N-terminal sequence of the enzyme has no homology with that of other reported phosphatases. M6Pase is a metaloprotein with manganese and cobalt as the preferred metal ions. It is N-glycosylated proteins with an isoelectric point of 4.7-4.8 and a pH optimum of 5. Based on its characteristics, M6Pase from P. chrysosporium seems to be a unique phosphatase responsible for posttranslation modification of LIP isozymes.
Both quality and quantity of organic matter (OM) in soils affect plant growth and health. Crop re... more Both quality and quantity of organic matter (OM) in soils affect plant growth and health. Crop residues and root exudates affect the activity of beneficial microorganisms, as well as pathogens (Chang et al, 1986). The effects of OM decomposition level in the soil on interactions of beneficial microorganisms and pathogens, and on plant growth have been largely overlooked (Grebus et al, 1994; Hoitink and Fahy, 1986). Both the mineral fraction and the yearly introduced organic residues, as well as their resulting transformations in soils, play a role in this complex. In addition, humic substances (HS), the most stable organic components in soil, may have both direct and indirect effects on plant growth (Chen and Aviad, 1990; Chen et al, 1994; Stevenson, 1985).
Page 1. Does organic farming increase soil suppression against Fusarium wilt of melon? Anat Yogev... more Page 1. Does organic farming increase soil suppression against Fusarium wilt of melon? Anat Yogev & Yael Laor & Jaacov Katan & Yitzhak Hadar & Rony Cohen & Shlomit Medina & Michael Raviv Received: 12 January 2011 ...
... M. Shenker and Y. Chen, Dep. of Soil and Water Sciences, Faculty of Agriculture, The Hebrew U... more ... M. Shenker and Y. Chen, Dep. of Soil and Water Sciences, Faculty of Agriculture, The Hebrew University of Jerusalem, PO Box 12, Rehovot, Israel; and Y. Hadar, Dep. ... The index (ofit) for the weighted sum of the squares of the p[H] deviation is given by - p[H]caicuiated)2 [4] ...
... 12 Compost Microbial Populations and Interactions with Plants Dror Minz, Stefan J. Green, May... more ... 12 Compost Microbial Populations and Interactions with Plants Dror Minz, Stefan J. Green, Maya Ofek, and ... TY, Stone AG, Kraakman B, Iannotti DA, Wilson GE, Madden LV, Hoitink HAJ (1997) Cross ... Ecol 35: 207216 DeSantis TZ Jr, Hugenholtz P, Keller K, Brodie EL, Larsen N ...
The stability constants of the fluorescent siderophore pseudobactin St3 (PSB 3) produced by Pseud... more The stability constants of the fluorescent siderophore pseudobactin St3 (PSB 3) produced by Pseudomonas putida strain 3 with Fe 3 , Cu 2+ , Mn 2+ , Zn 2+ , and Fe 2 * were determined using fluorescence spectroscopy and potentiometric titrations. Stability constants for PSB 3 , with Fe'*, Fe 2 *, Mn 2+ , and Zn 2+ were determined based on titration to saturation of a PSB 3 ligand solution with either of the metals, then back-titrating the solution with an EDTA solution along with simultaneous measurements of fluorescence and visible spectra. A nonlinear curve fitting between the fluorescence intensity (Y) and the concentration (C) of the metal or EDTA was used for the determination of the concentrations of the free and complexed ligands. The overall stability constant (log XML) obtained for Fe 3+ by this method was the same as that obtained by visible spectrosopy.The log AML values obtained by fluorescence spectroscopy for Mn 2+ and Zn 2+ (17.5 and 19.4, respectively) were in good agreement with log Km, values obtained by potentiometric titration (17.3 and 19.8, respectively). It was found that two chromatography bands obtained from PSB 3 solutions isolated and purified from cultures grown under different conditions cbelated Fe 3 + with practically the same affinity. The log Km. of PSB 3 with Fe 3+ , Zn 2+ , Cu 2+ , Mn 2+ , and Fe 2 * were calculated using the protonation constants determined by potentiometry (pA.i = 11.28, plfo = 7.74, pAi, = 5.35) and were found to be 29
Composting is a partially controlled bio-oxidative process through which highly heterogeneous org... more Composting is a partially controlled bio-oxidative process through which highly heterogeneous organic matter (OM) in its solid-state transforms into a humified material. The variability of the OM undergoing composting makes compost research a great challenge. Our purpose was to define chemical and plant response characteristics of a variety of composts, grouped based on their major source materials. Thirty-seven commercial composts
13C NMR spectra acquired with Cross-Polarization Magic Angle Spinning (CPMAS) were used to study ... more 13C NMR spectra acquired with Cross-Polarization Magic Angle Spinning (CPMAS) were used to study solid and finely ground samples of decomposing organic matter. Compost prepared from separated cattle manure (CSM-the solid fraction obtained by centrifugal separators from a slurry of cattle manure) at the start and maturity stages of the composting process was investigated. CPMAS I~C NMR spectra exhibited an increase in aromaticity and carboxyl groups content and a decrease in carbohydrates during composting. The CPMAS 13C NMR measurements agreed with those of crude fiber analyses. Cation exchange capacity increased from 62.8 to 180.9 meq/100g 014, while the C/N ratio decreased from 27.2 to 8.7 along the composting process. The procedure proposed to conduct CPMAS 13C NMR and FTIR measurements directly on ground decomposing organic matter without the application of extractions was shown to provide useful information on the decomposition process.
Rhizonus arrhizus was found to produce a novel siderophore named raphorin (Ra) when grown under F... more Rhizonus arrhizus was found to produce a novel siderophore named raphorin (Ra) when grown under Fe deficiency. Partially purified Fe‐Ra was found to alleviate Fe deficiency when applied to tomato plants grown in nutrient solutions buffered by either CaCO3 (pH 7.3) or HEPES (pH 7). Iron (Fe) uptake rate by plants mediated by Ra, and translocation rate to the shoot,
The geographical distribution and ecological habitats of the Pleurotus eryngii complex in Israel ... more The geographical distribution and ecological habitats of the Pleurotus eryngii complex in Israel are described from a study of 60 genotypes from 10 populations. Both MEA and PDA media were suitable for growth of all genotypes at all temperatures tested (4-37 mC). There was a high correlation between a coefficient of growth and the mean colony diameter growth rate. All genotypes reached the maximum growth at 27 m. Growth rate at 30 m was greater than at 19 m. We found highly significant (P 0n0001) variability among growth rates of Israeli genotypes, indicating ecogeographical differences among populations. The growth rate of 12 European genotypes from the Ukraine and Slovakia was higher than most of the Israeli genotypes when grown at 27 m (nonstress conditions), but Israeli genotypes tolerated 37 m (stress conditions) better, and recovered faster than European populations when returned to 27 m. We conclude that Israeli genotypes are better adapted to hot and dry climates than European genotypes. Based on multiple regression analyses, strong correlations were found between relative humidity and rainfall parameters, but not temperature, of the locations from which Israeli isolates were collected, and their growth rates. This indicates that, paradoxically, relative humidity and rainfall have a stronger effect than temperature on the adaptability of this complex to different environments.
The measurement of growth rate of three isolates-P14, P15 and P19 (obtained after regeneration of... more The measurement of growth rate of three isolates-P14, P15 and P19 (obtained after regeneration of protoplasts of the control strain) with significantly higher (PI 4, P19) or lower (PI 5) activity of laccase than the control strain (P. ostreatus florida F6) revealed similar patterns for P14 and P19; PI5 had a higher growth rate and the highest rate was observed in the control strain. The rate of mineralization of 14C-lignin on SSF (perlite) by strains F6 and PI5 was almost the same and it was higher than that of P14 and P 19 strains. The enzyme pattern of the individual isolates, studied by gel electrophoresis and activity staining of laccase, did not show any difference in isozyme patterns of the isolates, but there were differences in the level of gene expression.
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