Sulfur Deficiency Research Articles

Critical function of a Chlamydomonas reinhardtii putative polyphosphate polymerase subunit during nutrient deprivation.

Forward genetics was used to isolate Chlamydomonas reinhardtii mutants with altered abilities to acclimate to sulfur (S) deficiency. The ars76 mutant has a deletion that eliminates several genes, including VACUOLAR TRANSPORTER CHAPERONE1 (VTC1), which encodes a component of a polyphosphate polymerase complex. The ars76 mutant cannot accumulate arylsulfatase protein or mRNA and shows marked alterations in levels of many transcripts encoded by genes induced during S deprivation. The mutant also shows little acidocalcisome formation compared with wild-type, S-deprived cells and dies more rapidly than wild-type cells following exposure to S-, phosphorus-, or nitrogen (N)-deficient conditions. Furthermore, the mutant does not accumulate periplasmic L-amino acid oxidase during N deprivation. Introduction of the VTC1 gene specifically complements the ars76 phenotypes, suggesting that normal acidocalcisome formation in cells deprived of S requires VTC1. Our data also indicate that a deficiency in acidocalcisome function impacts trafficking of periplasmic proteins, which can then feed back on the transcription of the genes encoding these proteins. These results and the reported function of vacuoles in degradation processes suggest a major role of the acidocalcisome in reshaping the cell during acclimation to changing environmental conditions.

Balanced Nutrient Management for Crop Intensification and Livelihood Improvement: A Case Study from Watershed in Andhra Pradesh, India

Soil health assessment of farmers’ fields in watershed villages in Medak district, Andhra Pradesh, India showed widespread deficiencies of sulfur (S), boron (B), and zinc (Zn) in addition to organic carbon and phosphorus (P). Participatory on-farm trials on soil test-based application of deficient Zn, B, and S along with nitrogen (N) and P during 2009 to 2012 significantly increased crop yields over farmers’ practice (FP)—by 31% to 45% in chickpea, 15% to 16% in cotton, 12% to 15% in paddy, and 8% to 9% in sugarcane. Total soluble sugars in sugarcane under balanced nutrition (BN) increased by 13%. Residual benefits of S, B, and Zn were observed in succeeding chilly crop (12% higher yield). Benefit to cost (B:C) ratios of BN ranged between 2.8 to 8.5 in chickpea, 2.6 to 4.4 in cotton, 2.3 to 2.9 in paddy, and 7.1 to 11.4 in sugarcane, indicating economic feasibility for scaling-up.

Stability and Broad-Sense Heritability of Mineral Content in Potato: Copper and Sulfur

Sulfur and copper are important for human health. Sulfur deficiency is rare, but may occur in the elderly. How- ever, a large percentage of the U.S. population is deficient in copper. The purpose of this study was to determine the range of values for sulfur and copper available in advanced potato germplasm and varieties and estimate how much genetic variation exists for these two elements. Potato breeding lines and varieties in three multisite trials were evaluated for copper and sulfur content by wet ashing and Inductively Coupled ArgonPlasmaEmissionSpectrophotometer analysis.Stability and broad-sense heritability were determined. Among geno- types, copper content ranged from 2.0 to 4.5 ug-g �1 DW. This was a 2.25-fold difference. In these three trials, environment was never significant, while genotype by environment inter- actions were always significant. Genotype was significant in two of the regional trials. Broad-sense heritabilities were estimated to be 0.0, 0.93 and 0.51 for the Tri-State, Western Regional Russet and Western Regional Red/Specialty trials, respectively. Among genotypes, sulfur content ranged from 991 to 1488 ug-g �1 DW. The highest value was 50 % higher than the lowest. In these three trials, environment was never significant, while genotype x environment interactions were always significant. Genotype was significant in two of the regional trials. Broad-sense heritabilities were estimated to be 0.53, 0.68 and 0.88, for Tri-State, Western Regional Russet, and Western Regional Red/Specialty trials, respectively. For both sulfur and copper, selection in the Western Regional Russet and Western Regional Red/Specialty trials is likely to lead to an increase in content. Selection for sulfur in the Tri- State would result in a gain as well. These results suggest that genetic improvements could be made to potato to enhance the concentrations of these minerals.

A system based network approach to ethanol tolerance in Saccharomyces cerevisiae.

BackgroundSaccharomyces cerevisiae has been widely used for bio-ethanol production and development of rational genetic engineering strategies leading both to the improvement of productivity and ethanol tolerance is very important for cost-effective bio-ethanol production. Studies on the identification of the genes that are up- or down-regulated in the presence of ethanol indicated that the genes may be involved to protect the cells against ethanol stress, but not necessarily required for ethanol tolerance.ResultsIn the present study, a novel network based approach was developed to identify candidate genes involved in ethanol tolerance. Protein-protein interaction (PPI) network associated with ethanol tolerance (tETN) was reconstructed by integrating PPI data with Gene Ontology (GO) terms. Modular analysis of the constructed networks revealed genes with no previously reported experimental evidence related to ethanol tolerance and resulted in the identification of 17 genes with previously unknown biological functions. We have randomly selected four of these genes and deletion strains of two genes (YDR307W and YHL042W) were found to exhibit improved tolerance to ethanol when compared to wild type strain.The genome-wide transcriptomic response of yeast cells to the deletions of YDR307W and YHL042W in the absence of ethanol revealed that the deletion of YDR307W and YHL042W genes resulted in the transcriptional re-programming of the metabolism resulting from a mis-perception of the nutritional environment. Yeast cells perceived an excess amount of glucose and a deficiency of methionine or sulfur in the absence of YDR307W and YHL042W, respectively, possibly resulting from a defect in the nutritional sensing and signaling or transport mechanisms. Mutations leading to an increase in ribosome biogenesis were found to be important for the improvement of ethanol tolerance. Modulations of chronological life span were also identified to contribute to ethanol tolerance in yeast.ConclusionsThe system based network approach developed allows the identification of novel gene targets for improved ethanol tolerance and supports the highly complex nature of ethanol tolerance in yeast.

Partitioning of Newly Absorbed and Previously Stored Nitrogen and Sulfur Under Sulfate Deficient Nutrition

Sulfur (S) deficiency effects on nitrogen (N) and S fluxes during vegetative growth of Brassica napus was investigated by tracing 15N and 34S for 9 d of S-sufficient [1.5 mM sulfate (SO42-)] and S-deficient (0.05 mM SO42-) condition. A significant decrease in leaf osmotic potential and chlorophyll content was apparent after 9 d of S-deficiency. Sulfur uptake during 9 d was remarkably decreased by 94.3% by S-deficiency, whereas no significant change occurred for N uptake. The N and S deriving from uptake were mainly allocated to the leaves in control plants, but the S flow into leaves was largely restricted under S-deficient condition. The remobilization of stored N and S were mainly issued only from leaves in control plants, while from leaves and petiole in S-deficient ones. The remobilization of N and S mainly issued from leaves flows into the roots both in control and S-deficient plants.

Enhanced photoluminescence from ordered arrays of cadmium sulfide nanotubes synthesized using nanoscale chemical reactors.

We report enhanced room temperature photoluminescence from ordered arrays of few micrometers long cadmium sulfide nanotubes fabricated using 'nanoscale chemical reactors' of porous alumina by a unique two-chamber synthesis without using any surfactants. Photoluminescence from these nanotubes is -20 times larger than that of nanocrystalline cadmium sulfide particles prepared by bulk mixing of the same reactants. However, we rule out any quantum size effect as a source of enhanced photoluminescence from these intentionally un-passivated nanotubes. We identify sulfur deficiency in these nanotubes and directional orientation of these ordered nanotube arrays as the main reason for its superior photoluminescence as compared to agglomerated nanocrystallites of CdS prepared by bulk mixing.

Identification of nutrient deficiency in maize and tomato plants by in vivo chlorophyll a fluorescence measurements

The impact of some macro (Ca, S, Mg, K, N, P) and micro (Fe) nutrients deficiency on the functioning of the photosynthetic machinery in tomato (Solanum lycopersicum L.) and maize (Zea mays L.) plants grown in hydroponic cultures were investigated. Plants grown on a complete nutrient solution (control) were compared with those grown in a medium, which lacked one of macro- or microelements. The physiological state of the photosynthetic machinery in vivo was analysed after 14-days of deficient condition by the parameters of JIP-test based on fast chlorophyll a fluorescence records. In most of the nutrient-deficient samples, the decrease of photochemical efficiency, increase in non-photochemical dissipation and decrease of the number of active photosystem II (PSII) reaction centres were observed. However, lack of individual nutrients also had nutrient-specific effects on the photochemical processes. In Mg and Ca-deficient plants, the most severe decrease in electron donation by oxygen evolving complex (OEC) was indicated. Sulphur deficiency caused limitation of electron transport beyond PSI, probably due to decrease in the PSI content or activity of PSI electron acceptors; in contrary, Ca deficiency had an opposite effect, where the PSII activity was affected much more than PSI. Despite the fact that clear differences in nutrient deficiency responses between tomato and maize plants were observed, our results indicate that some of presented fluorescence parameters could be used as fluorescence phenotype markers. The principal component analysis of selected JIP-test parameters was presented as a possible species-specific approach to identify/predict the nutrient deficiency using the fast chlorophyll fluorescence records.

Composition dependent optical, structural and photoluminescence behaviour of CdS:Al thin films by chemical bath deposition method

Undoped and Al doped CdS thin films were deposited successfully on glass plates using chemical bath deposition method at 80°C with different Al concentrations between 0 and 8%. X-ray diffraction spectra revealed that undoped CdS thin film had cubic structure which was turned to mixed phase of cubic and hexagonal by Al doping. The noticed decrease in d-value, cell parameters, bond length and volume up to 4% of Al is due to the substitution of Al3+ into Cd–S lattice whereas the increase of these parameters beyond 4% is due to the formation of defects. Structural, optical and photoluminescence properties of Al doped CdS thin films were studied using X-ray diffraction, energy dispersive X-ray, scanning electron microscopy, UV–Vis absorption, Fourier transform infra red spectroscopy and photoluminescence spectra. The enhanced crystal size at lower Al concentrations is due to the proper substitution of Al3+ and the reduced crystal size after Al=4% is due the interstitial defects of Al3+ in Cd–S lattice. The continuous red shift of energy gap from 2.18eV (Al=0%) to 1.96eV (Al=8%) is elucidated by increasing amount of sulfur deficiency by Al doping. The presence of functional groups and chemical bonding were confirmed by FTIR spectra. Room temperature photoluminescence spectra showed the two well distinct and strong bands; blue band around 409 to 415nm and green band around 538 to 547nm. The change in intensity and their shift were discussed in detail.

Long-term sulphur starvation of Arabidopsis thaliana modifies mitochondrial ultrastructure and activity and changes tissue energy and redox status

Sulphur, as a constituent of amino acids (cysteine and methionine), iron-sulphur clusters, proteins, membrane sulpholipids, glutathione, glucosinolates, coenzymes, and auxin precursors, is essential for plant growth and development. Absence or low sulphur concentration in the soil results in severe growth retardation. Arabidopsis thaliana plants grown hydroponically for nine weeks on Knop nutrient medium without sulphur showed morphological symptoms of sulphur deficiency. The purpose of our study was to investigate changes that mitochondria undergo and the role of the highly branched respiratory chain in survival during sulphur deficiency stress. Ultrastructure analysis of leaf mesophyll cells of sulphur-deficient Arabidopsis showed heterogeneity of mitochondria; some of them were not altered, but the majority had swollen morphology. Dilated mitochondria displayed a lower matrix density and fewer cristae compared to control mitochondria. Disintegration of the inner and outer membranes of some mitochondria from the leaves of sulphur-deficient plants was observed. On the contrary, chloroplast ultrastructure was not affected. Sulphur deficiency changed the respiratory activity of tissues and isolated mitochondria; Complex I and IV capacities and phosphorylation rates were lower, but external NAD(P)H dehydrogenase activity increased. Higher external NAD(P)H dehydrogenase activity corresponded to increased cell redox level with doubled NADH/NAD ratio in the leaf and root tissues. Sulphur deficiency modified energy status in the tissues of Arabidopsis plants. The total concentration of adenylates (expressed as ATP+ADP), measured in the light, was lower in the leaves and roots of sulphur-deficient plants than in the controls, which was mainly due to the severely decreased ATP levels. We show that the changes in mitochondrial ultrastructure are compensated by the modifications in respiratory chain activity. Although mitochondria of Arabidopsis tissues are affected by sulphur deficiency, their metabolic and structural features, which readily reach new homeostasis, make these organelles crucial for adaptation of plants to survive sulphur deficiency.

Phase Stability and Thermoelectric Properties of CuFeS2-Based Magnetic Semiconductor

Recently, based on measurement results below 400 K, we suggested that chalcopyrite CuFeS2-based alloys hold promise as thermoelectric materials. In this study, we have investigated the phase stability of such compounds and measured their thermoelectric properties at temperatures above 400 K. Thermogravimetric data indicate that the samples synthesized by a spark plasma sintering method were stable up to 700 K, above which sulfur deficiency becomes prominent. The electrical resistivity of the electron-doped samples showed metallic behavior up to 700 K. The Seebeck coefficients show large negative values of about −300 μV/K above 400 K. As a result, the power factor of Cu0.97Fe1.03S2 is ~1 mW/K2m in the temperature range of 400 K to 600 K.

Antioxidant Status of Vigna mungo L. in Response to Sulfur Nutrition

Black gram (Vigna mungo L. var. DPU-88-31), an edible legume, was grown at 1, 2, 4, 6, and 8 meq S L−1 to study the effect of deficient and excess level of sulfur on oxidative metabolism. Plants supplied by 4 meq S L−1 showed optimum yield. Sulfur deficient plants (1 and 2 meq S L−1) showed reduction in growth and chlorosis of young leaves. Tissue sulfur and cysteine concentration was increased with increasing sulfur supply. The thresholds for critical concentration of sulfur deficiency and toxicity were 0.315% and 0.434% dry weight. Biomass and photoassimilatory pigments were decreased and carbohydrates (sugar and starch) were accumulated in leaves of sulfur deficient and excess plants. Accumulation of hydrogen peroxide and thiobarbituric acid reactive substances in sulfur deficient and excess plants caused oxidative damage in plants which was also evident by the increase in the activity of superoxide dismutase, catalase, peroxidase, ascorbate peroxidase, glutathione reductase, and concentration of ascorbate and nonprotein thiols.

Deposition of GaV4S8 thin films by H2S/Ar reactive sputtering for ReRAM applications

The chalcogenide compound GaV4S8 is promising for applications as active materials in non-volatile memory applications. We report here a comprehensive study on the thin-film deposition of this compound using a stoichiometric GaV4S8 target and H2S/Ar reactive sputtering. We show that a fraction of 0.5% to 1% of H2S in the reactive plasma is sufficient to compensate the sulfur deficiency that appears in films deposited in pure Ar plasma. This reactive plasma method allows avoiding the addition of elemental sulfur during the annealing treatment required to obtain a crystallized and stoichiometric GaV4S8 layer. A simple Au/GaV4S8/Au structure presents a resistive switching behaviour well suited for non-volatile memory applications.

EFFECT OF SOIL FACTORS ON SULPHUR CHANGES AND AVAILABILITY FOR PLANTS

The study presents the analysis of the effect of soil factors such as oxidation, reduction, immobilization, mineralization, leaching, ion competition, and water management on sulfur metabolism in soil and its availability to the crops. Sulfur is one of the nutrients that largely affects the quantity and quality of crop yields, and is also a component of many compounds, the lack of which causes some disturbances to the development of plants and diseases in humans and animals. Despite such a great importance, it was not subject to agricultural research until the early 80s, and was not taken into consideration when determining the fertilizing needs of plants. However, the situation has changed in recent years, when problems associated with sulfur deficiency in crop production began more and more to be emphasized. The absence of this component is to be expected especially at the lighter, usually acidic mineral soils, located away from industrial centers. Therefore, the transformation of sulfur in the soil and its availability to the crop becomes an important issue.

Integrated Plant Genetic and Balanced Nutrient Management Enhances Crop and Water Productivity of Rainfed Production Systems in Rajasthan, India

Analysis of soils from 421 farmers’ fields in eastern districts of Rajasthan, India, revealed widespread deficiencies of sulfur (S; 43 to 87% fields deficient), boron (B; 25 to 100%), and zinc (Zn; 0 to 94%) in addition to phosphorus (P; 10 to 73%) and soil organic carbon (1 to 84%). An integrated approach of application of deficient S, B, and Zn along with N and P to high-yielding crop cultivars increased yield over farmers’ practice of N and P application to local cultivars by 92 to 204% in maize, 115 to 167% in pearl millet, and 150% in groundnut. Benefit-to-cost ratio of the integrated strategy varied from 3.33 to 8.03 in maize, 2.92 to 3.40 in pearl millet, and 1.15 in groundnut. The integrated approach effectively utilized scarce water in food production and increased rainwater-use efficiency at 67 to 145 kg mm−1 ha−1 from 21 to 50 kg mm−1 ha−1 under farmers’ practice.

Hydroprocessing of waste cooking oil over a dispersed nano catalyst: Kinetics study and temperature effect

The kinetics of hydrodeoxygenation of waste cooking oil (WCO) is investigated with unsupported CoMoS catalysts. A kinetic model is established and a comprehensive analysis of each reaction pathway is carried out. The results show that hydrodecarbonylation/decarboxylation (HDC) routes are the predominant reaction pathways in the elimination of oxygen, with the rate constant three times as high as that of hydrodeoxygenation (HDO). However, the HDC activity of the CoMoS catalyst deactivates due to gradual loss of sulfur from the catalyst. HDO process is insensitive to the sulfur deficiency. The kinetic modeling shows that direct hydrodecarbonylation of fatty acids dominates the HDC routes and, in the HDO route, fatty acids are transferred to aldehydes/alcohols and then to C18 hydrocarbons, a final product, and the reduction of acids is the rate limiting step. The HDO route via alcohols is dominant over aldehydes due to a significantly higher reaction rate constant. The difference of C18/C17 ratio in unsupported and supported catalysts show that a support with Lewis acid sites may play an important role in the selectivity for the hydrodeoxygenation pathways and promoting the final product quality.

How do phosphorus, potassium and sulphur affect plant growth and biological nitrogen fixation in crop and pasture legumes? A meta-analysis

Worldwide, legumes are grown on approximately 250Mha and fix about 90Tg of N2 per year. Plants involved in biological nitrogen fixation (BNF) are particularly sensitive to deficiencies of phosphorus (P), potassium (K) and sulphur (S). These nutrients can affect BNF directly; this is modulating growth of rhizobia, nodule formation and functioning, or indirectly by affecting the growth of the host plant. However, several process and mechanisms remain unclear. We compiled a data set (63 studies) on the effects of P, K, and S deficiency on shoot mass, nodule mass and number, nitrogenase activity (estimated by the acetylene reduction activity test, ARA) and the concentration of N, P, K and S in shoots and nodules. Our aims were (1) to compare the relative sensitivity of these traits to nutrient deficiency and (2) to probe for nutrient-specific patterns in trait responses.Our quantitative analysis confirms that nodule growth and number are more sensitive than shoot mass in response to deficiency of P, K and S. In addition, nodule activity decreases more than both shoot and nodule mass, which indicates a reduction in nodule productivity; this is likely related with direct effects of these nutrients on physiological and metabolic processes of nodules. The conserved shoot N concentration, in comparison to concentration of P, K and S indicates a relatively greater accumulation of N that matches the proposed N-feedback mechanism down-regulating BNF in nutrient-deficient systems. Despite some nutrient-specific differences, i.e. smaller nodules and higher N/K ratio with shortage of P and K, respectively, the patterns of growth, nodule activity and nutrient concentration were similar for all three nutrients P, K and S. This indicates that a unique mechanism could be depressing BNF (N-feedback) in conjunction with direct effects of the nutrients on nodule activity.Scarcity of data related to N, K and S concentration in nodules is a major constrain for deep analysis of the deficiencies of the nutrients. Critical concentrations of P, K and S in plant and nodule tissues are also a major gap. Models are needed that integrate the direct effect of the nutrients on nodule growth and activity with the N-feedback mechanism.

Legume adaptation to sulfur deficiency revealed by comparing nutrient allocation and seed traits in Medicago truncatula

Reductions in sulfur dioxide emissions and the use of sulfur-free mineral fertilizers are decreasing soil sulfur levels and threaten the adequate fertilization of most crops. To provide knowledge regarding legume adaptation to sulfur restriction, we subjected Medicago truncatula, a model legume species, to sulfur deficiency at various developmental stages, and compared the yield, nutrient allocation and seed traits. This comparative analysis revealed that sulfur deficiency at the mid-vegetative stage decreased yield and altered the allocation of nitrogen and carbon to seeds, leading to reduced levels of major oligosaccharides in mature seeds, whose germination was dramatically affected. In contrast, during the reproductive period, sulfur deficiency had little influence on yield and nutrient allocation, but the seeds germinated slowly and were characterized by low levels of a biotinylated protein, a putative indicator of germination vigor that has not been previously related to sulfur nutrition. Significantly, plants deprived of sulfur at an intermediary stage (flowering) adapted well by remobilizing nutrients from source organs to seeds, ensuring adequate quantities of carbon and nitrogen in seeds. This efficient remobilization of photosynthates may be explained by vacuolar sulfate efflux to maintain leaf metabolism throughout reproductive growth, as suggested by transcript and metabolite profiling. The seeds from these plants, deprived of sulfur at the floral transition, contained normal levels of major oligosaccharides but their germination was delayed, consistent with low levels of sucrose and the glycolytic enzymes required to restart seed metabolism during imbibition. Overall, our findings provide an integrative view of the legume response to sulfur deficiency.

Study on The Potency of Soil Microbes Isolated from Andisols of Dieng, Central Java, as S-Oxidizing Biofertilizer Inoculant

Title : Study on The Potency of Soil Microbes Isolated from Andisols of Dieng, Central Java, as S-Oxidizing Biofertilizer Inoculant. The problem of nutrient deficiences tend to increase, including sulfur deficiency. The use of high purity NPK fertilizers stimulate sulfur deficiency in agricultural land. This problem can be corrected by the use of elemental sulfur accompanied with S-oxidizing biofertilizer. The study aimed to evaluate the potential of sulfur oxidizing microbial isolated from Andisols of Dieng Central Java as S-oxidizing inoculant. Andisols Dieng naturally contains high sulfur that allegedly inhabited many sulfur-oxidizing microbials. The research consisted of two experiments, each arranged in completely randomized design (CRD). Each experiment consist of two factors namely the kind of microbial isolated from Andisols Dieng and incubation time. The first experiment used Czapek-dox+elemental sulfur medium, while the second experiment used vermicompost as medium. The observed variables include soluble-S, bacterial density, biomass of fungi and medium pH. One isolate of bacteria (I1)and three isolates of fungi (F1, F2 and F3) taken from Andisol of Dieng showing their ability to oxidize sulfur in Czapek-dok agar medium. They were used as isolates in the experiment. The result of the first experiment showed that the oxidized sulfur increased with the length of incubation time as indicated by the increase of soluble-S, bacterial cell density or fungi biomass in the medium followed by the decrease of pH. The second experiment showed that the population of bacteria or fungi isolates and soluble-S of vermicompost were increased collaterally with incubation time. The fungi isolate of F2 have the highest potency as inoculant of S-oxidizing biofertilizer as shown by it ability to survive, grows and oxidize S both in Czapek-dox+elemental sulfur liquid medium as well as in vermicompost medium.

Study on The Potency of Soil Microbes Isolated from Andisols of Dieng, Central Java, as S-Oxidizing Biofertilizer Inoculant

Title : Study on The Potency of Soil Microbes Isolated from Andisols of Dieng, Central Java, as S-Oxidizing Biofertilizer Inoculant. The problem of nutrient deficiences tend to increase, including sulfur deficiency. The use of high purity NPK fertilizers stimulate sulfur deficiency in agricultural land. This problem can be corrected by the use of elemental sulfur accompanied with S-oxidizing biofertilizer. The study aimed to evaluate the potential of sulfur oxidizing microbial isolated from Andisols of Dieng Central Java as S-oxidizing inoculant. Andisols Dieng naturally contains high sulfur that allegedly inhabited many sulfur-oxidizing microbials. The research consisted of two experiments, each arranged in completely randomized design (CRD). Each experiment consist of two factors namely the kind of microbial isolated from Andisols Dieng and incubation time. The first experiment used Czapek-dox+elemental sulfur medium, while the second experiment used vermicompost as medium. The observed variables include soluble-S, bacterial density, biomass of fungi and medium pH. One isolate of bacteria (I1)and three isolates of fungi (F1, F2 and F3) taken from Andisol of Dieng showing their ability to oxidize sulfur in Czapek-dok agar medium. They were used as isolates in the experiment. The result of the first experiment showed that the oxidized sulfur increased with the length of incubation time as indicated by the increase of soluble-S, bacterial cell density or fungi biomass in the medium followed by the decrease of pH. The second experiment showed that the population of bacteria or fungi isolates and soluble-S of vermicompost were increased collaterally with incubation time. The fungi isolate of F2 have the highest potency as inoculant of S-oxidizing biofertilizer as shown by it ability to survive, grows and oxidize S both in Czapek-dox+elemental sulfur liquid medium as well as in vermicompost medium.

Sulfane sulfur deficiency in malignant cells, increasing the inhibiting action of acetone cyanohydrin in tumor growth

To demonstrate the irreversible poisoning action of the acetone cyanohydrin (AC) in malignant cells. Thirty male Swiss mice were inoculated with 1 x 10³ Ehrlich tumor (ET) cells. The mice were divided into three groups (n=10): CG (saline); ACG1 (1.864 mg/Kg of AC) and ACG2 (2.796 mg/Kg of AC), treated every 48 hours from day 3 until day 13. On day 15 the mice were euthanized and the number of viable cells in ascites was determined. In the meantime, ET cells were incubated with AC (0.5, 1.0, 2.0 μg/mL). Cell viability and percentage of growth inhibition (PGI) were checked after one, two, three, four, 18 and 24 hours. There was reduction in volume and number of viable cells in ACG1 and ACG2 compared to CG. In ACG1 one of the animals did not present ascites. In ACG2 two mice did not present ascites and in CG none of the mice present ascites. The action of AC was dose and time dependent and there was no significant difference among the three doses. The acetone cyanohydrin promoted reduction of the tumor and also prevented tumor development in 20% of the treated animals.