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PubMed2006

Effect of sulfur-containing compounds on Bacillus cellulosome-associated 'CMCase' and 'Avicelase' activities.

The isolation of cellulosomes from clostridial sources has been extensively studied; however, the isolation of cellulosomes from facultative soil anaerobes of the family Bacillaceae is not as well characterized. The Bacillus cellulosome (celluloxylanosome) essentially consists of two complex components: C-I and C-II. This multi-component complex enables Bacillus to degrade a variety of carbonaceous compounds as it is composed of several enzymes, such as cellulases, xylanases and other degradative enzymes. The cellulosomal cellulases from Bacillus megaterium were purified using cellulose affinity chromatography, followed by Sepharose 4B gel filtration chromatography. The objective of this investigation was to establish the effect of sulfate and sulfide on cellulosomal 'cellulase' activity. An increase in sulfide concentration led to a general enhancement of cellulosomal-associated cellulolytic activity, whereas an increase in sulfate concentration resulted in an inhibition of the cellulosome-associated cellulolytic activity.

Bacillus↗
PubMed1984

Developmental changes in the metabolism of 3-methylthiopropionate in the rat.

The oxidation of 3-methylthiopropionate (MTP), a product in the transamination pathway of methionine metabolism, was measured in rats from 1 to 400 days of age. The metabolic capacity of liver homogenates to produce volatile sulfur compounds (methanethiol and/or hydrogen sulfide) from [35S]MTP increased sixfold during the first week of life, remained at that level through weaning, then gradually decreased to essentially the value observed in the 1-day-old rat by 400 days of age. This pattern is not altered when the data are expressed in relation to tissue O2 consumption. This implies that the greater ability of young rats to produce volatile sulfur compounds is not simply a reflection of their greater metabolic rate (kilocalorie/kilogram per day). In contrast to experiments in vitro, the ability to convert a tracer dose of [35S]MTP to urinary sulfate increased from 50% of the dose in the 15-day-old rat to 80% in the 24-, 50- and 400-day-old rats. This difference between the ability to produce volatile sulfur compounds and to excrete them as sulfate may explain the toxicity of methionine in young animals.

Aging↗
PubMed2003

Development of a novel process for the biological conversion of H2S and methanethiol to elemental sulfur.

The feasibility of anaerobic treatment of wastewater containing methanethiol (MT), an extremely volatile and malodorous sulfur compound, was investigated in lab-scale bioreactors. Inoculum biomass originating from full-scale anaerobic wastewater treatment facilities was used. Several sludges, tested for their ability to degrade MT, revealed the presence of organisms capable of metabolizing MT as their sole source of energy. Furthermore, batch tests were executed to gain a better understanding of the inhibition potential of MT. It was found that increasing MT concentrations affected acetotrophic organisms more dramatically than methylotrophic organisms. Continuous reactor experiments, using two lab-scale upflow anaerobic sludge bed (UASB) reactors (R1 and R2), aimed to determine the maximal MT load and the effect of elevated sulfide concentrations on MT conversion. Both reactors were operated at a hydraulic retention time (HRT) of about 7 hours, a temperature of 30 degrees C, and a pH of between 7.3 and 7.6. At the highest influent MT concentration applied, 14 mM in R1, corresponding to a volumetric loading rate of about 50 mM MT per day, 87% of the organic sulfur was recovered as hydrogen sulfide (12.2 mM) and the remainder as volatile organic sulfur compounds (VOSCs). Upon decreasing the HRT to 3.5 to 4.0 h at a constant MT loading rate, the sulfide concentration in the reactor decreased to 8 mM and MT conversion efficiency increased to values near 100%. MT conversion was apparently inhibited by the high sulfide concentrations in the reactor. The specific MT degradation rate, as determined after 120 days of operation in R1, was 2.83 +/- 0.27 mmol MT g VSS(-1) day(-1). During biological desulfurization of liquid hydrocarbon phases, such as with liquefied petroleum gas (LPG), the combined removal of hydrogen sulfide and MT is desired. In R2, the simultaneous addition of sodium sulfide and MT was therefore studied and the effect of elevated sulfide concentrations was investigated. The addition of sodium sulfide resulted in enhanced disintegration of sludge granules, causing significant washout of biomass. Additional acetate, added to stimulate growth of methanogenic bacteria to promote granulation, was hardly converted at the termination of the experimental period.

Bacteria, Anaerobic↗
PubMed2003

Kinetic spectrophotometric determination of some sulfur containing compounds in pharmaceutical preparations and human serum.

A kinetic spectrophotometric method was developed for the determination of carbocisteine, ethionamide, thioctic acid and penicillamine based on the catalytic effect on the reaction between sodium azide and iodine in aqueous solution. Ten to 100 microg ml(-1) of carbocisteine and ethionamide, 0.1-1 microg ml(-1) of thioctic acid and 0.01-0.1 microg ml(-1) of penicillamine could be determined, respectively, by measuring the decrease in the absorbance of iodine at 348 nm by a fixed time method. The decrease in the absorbance in the first 5 min from the initiation of the reaction is related to the concentration of the drugs. The detection limits were 0.47, 0.71, 0.018 and 9.38 x 10(-4) microg ml(-1) for the four drugs, respectively. The proposed procedure was successfully applied in the determination of these drugs in pharmaceutical preparations and human serum.

Calibration↗
PubMed2004

Influence of irradiation and storage on the quality of ready-to-eat turkey breast rolls.

Influence of irradiation and storage on the quality of ready-to-eat (RTE) turkey breast rolls was investigated. Commercial oven roasted turkey breast rolls purchased from local stores were sliced and vacuum packaged. The sliced samples were randomly divided into 3 groups and irradiated at 0, 1.0, or 2.0 kGy using a linear accelerator. Color, 2-TBA-reactive substances (TBARS), sensory characteristics, and volatiles were evaluated at 0, 7, and 14 d of storage. Irradiation increased color a* value of turkey breast rolls. Irradiation and storage did not influence TBARS values. Sensory evaluation showed that irradiation significantly increased sulfury flavor. Because a dramatic increase in sulfur compounds was detected in irradiated samples, the sulfury flavor should be due to the sulfur compounds formed during irradiation. Irradiation also increased the amounts of acetylaldehyde, 2-methyl butanal, 3-methyl butanal, benzene, and toluene. It was concluded that irradiation significantly influenced the odor and flavor of RTE turkey breast rolls under vacuum packaging conditions. Therefore, strategies to prevent negative changes in the quality of irradiated RTE turkey breast rolls are needed.

Animals↗
PubMed2001

A historical perspective on garlic and cancer.

Epidemiological and laboratory studies provide insight into the anticarcinogenic potential of garlic and its constituent compounds. Both water- and lipid-soluble allyl sulfur compounds are effective in blocking a myriad of chemically induced tumors. Part of the protection from these compounds probably relates to a block in nitrosamine formation and metabolism. However, blockage in the initiation and promotion phases of the carcinogenicity of various compounds, including polycyclic hydrocarbons, provide evidence that garlic and its constituents can alter several phase I and II enzymes. Their ability to block experimentally induced tumors in a variety of sites including skin, mammary and colon, suggests a general mechanism of action. Changes in DNA repair and in immunocompetence may also account for some of this protection. Some, but not all, allyl sulfur compounds can also effectively retard tumor proliferation and induce apoptosis. Changes in cellular thiol and phosphorylation stains may account for some of these antitumorigenic properties. The anticarcinogenic potential of garlic can be influenced by several dietary components including specific fatty acids, selenium, and vitamin A. Since garlic and its constituents can suppress carcinogen formation, carcinogen bioactivation, and tumor proliferation it is imperative that biomarkers be established to identify which individuals might benefit most and what intakes can occur with ill consequences.

Allyl Compounds↗
PubMed1985

Effects of disulfiram, diethyldithiocarbamate, bisethylxanthogen, and benzyl isothiocyanate on glutathione transferase activities in mouse organs.

Four sulfur compounds known to inhibit tumorigenic effects of chemical carcinogens were administered to female CD-1 mice at 0.5% of the diet for 14 days, and their effects on cytosolic glutathione transferase (EC 2.5.1.18) specific activities were examined in liver, lung, kidney, urinary bladder, forestomach, proximal small intestine, and colon. Disulfiram, sodium diethyldithiocarbamate, bisethylxanthogen, and benzyl isothiocyanate elevated glutathione transferase specific activities in most of the organs examined. The four sulfur compounds differed in the extents and organ specificities of their effects on these enzyme activities. In the liver, bisethylxanthogen and benzyl isothiocyanate increased glutathione transferase activities to at least 3 times control levels and caused differential increases in the isozyme patterns observed after isoelectric focusing of the cytosols. Bisethylxanthogen also increased immunoreactive glutathione transferase in liver cytosol. Recrystallized disulfiram was less effective in enhancing hepatic glutathione transferase activities than was commercial (97%) disulfiram. Among the six extrahepatic organs examined, the small intestine and the forestomach exhibited the greatest response of glutathione transferase activities to each of the four sulfur compounds. Benzyl isothiocyanate was most effective in these "portal of entry" organs but less effective than bisethylxanthogen in the other extrahepatic organs examined. Bisethylxanthogen elicited significant increases in glutathione transferase activities in liver, lung, and small intestine even when administered at 0.01% to 0.05% of the diet, suggesting that this compound may have considerable potential as an inhibitor of carcinogens susceptible to enzymatic conjugation with glutathione.

Animals↗
PubMed1990

The formation of hydrogen sulfide and methyl mercaptan by oral bacteria.

The capacity to form volatile sulfur compounds was tested in bacteria isolated from subgingival microbiotas and in a representative number of reference strains. A majority of the 75 tested oral bacterial species and 7 unnamed bacterial taxa formed significant amounts of hydrogen sulfide from L-cysteine. The most active bacteria were found in the genera Peptostreptococcus, Eubacterium, Selenomonas, Centipeda, Bacteroides and Fusobacterium. Methyl mercaptan from L-methionine was formed by some members of the genera Fusobacterium, Bacteroides, Porphyromonas and Eubacterium. When incubated in serum for 7 d, the most potent producers of hydrogen sulfide were Treponema denticola and the black-pigmented species, Bacteroides intermedius, Bacteroides loescheii, Porphyromonas endodontalis and Porphyromonas gingivalis. P. endodontalis and P. gingivalis also produced significant amounts of methyl mercaptan in serum. No other volatile sulfur compound was detected in serum or in the presence of L-cysteine and L-methionine. These findings significantly increase the list of oral bacteria known to produce volatile sulfur compounds.

Bacteroides↗
PubMed1972

The sulfur cycle.

Even granting our uncertainties about parts of our model of the sulfur cycle, we can draw some conclusions from it: 1) Man is now contributing about one half as much as nature to the total atmospheric burden of sulfur compounds, but by A.D. 2000 he will be contributing about as much, and in the Northern Hemisphere alone he will be more than matching nature. 2) In industrialized regions he is overwhelming natural processes, and the removal processes are slow enough (several days, at least) so that the increased concentration is marked for hundreds to thousands of kilometers downwind. 3) Our main areas of uncertainty, and ones that demand immediate attention because of their importance to the regional air pollution question, are: (i) the rates of conversion of H(2)S and SO(2) to sulfate particles in polluted as well as unpolluted atmospheres; (ii) the efficiency of removal of sulfur compounds by precipitation in polluted air. And for a better understanding of the global model we need to know: (i) the amount of biogenic H(2)S that enters the atmosphere over the continents and coastal areas; (ii) means of distinguishing man-made and biogenic contributions to excess sulfate in air and precipitation; (iii) the volcanic production of sulfur compounds, and their influence on the particle concentration in the stratosphere; (iv) the large-scale atmospheric circulation patterns that exchange air between stratosphere and troposphere (although absolute amounts of sulfate particles involved are small relative to the lower tropospheric burden); (v) the role of the oceans as sources or sinks for SO(2).

Air Pollution↗
PubMed2006

Association between oral malodor and measurements obtained using a new sulfide monitor.

OBJECTIVE: The purpose of this study was to evaluate the ability of a new volatile sulfur compounds (VSCs) monitor to assess oral malodor in subjects and compare its performance with those of organoleptic testing and gas chromatography. METHODS: The mouth air of 260 patients was measured by three methods: VSCs monitor (Breathtron), organoleptic test by two judges and gas chromatography (GC). Mcnemar test and Pearson correlation were used to analyze the data among these methods. RESULTS: The log values of VSCs measured by a sulfide monitor were significantly correlated with the organoleptic ratings, and also with log values of H(2)S, CH(3)SH, and (CH(3))(2)S determined by GC (P<0.01). Using the results of organoleptic and GC to classify subjects into normal and malodor groups, the sulfide monitor's sensitivity was shown to be more than 79% and the specificity was 61-73%. CONCLUSIONS: This sulfide monitor could be used for oral malodor measurement, moreover, according to its portability, it could be conveniently used for clinical setting and field surveys.

Breath Tests↗
PubMed2006

Short communication: empirical and mechanistic evidence for the role of pyridoxal-5'-phosphate in the generation of methanethiol from methionine.

The catabolism of the sulfur-containing AA Met to form flavor-active volatile sulfur compounds (VSC) is an important mechanism in flavor development during cheese maturation. Numerous enzymes catalyzing AA catabolism require the presence of the cofactor pyri-doxal-5'-phosphate (PLP). In fact, reports have shown that some of these reactions can be catalyzed by PLP alone, albeit at a reduced rate. We hypothesized that, as a specific application in cheese flavor reactions, PLP can react directly with free Met to generate a specific VSC, methanethiol (MTH). In this study, the ability of PLP to catalyze MTH generation from Met was examined under "cheeselike" conditions of salt and pH. Methionine and varying concentrations of PLP were incubated in a buffer (pH 5.2 + 4.0% NaCl) analogous to the aqueous phase of aged Cheddar cheese. Samples were analyzed using headspace solid-phase microextraction, and relative concentrations of VSC were determined by gas chromatography-mass spectrometry. Results showed MTH, dimethyl disulfide, and dimethyl trisulfide production when Met and PLP were incubated together at 7 degrees C (cheese-aging temperature). These results indicate that the production of VSC from Met can occur nonenzymatically as catalyzed by free PLP.

Cheese↗
PubMed1996

Hyperthermophiles in the history of life.

Prokaryotes requiring extremely high growth temperatures (optimum 80-110 degrees C) have recently been isolated from water-containing terrestrial, subterranean and submarine high temperature environments. These hyperthermophiles consist of primary producers and consumers of organic matter, forming unique high temperature ecosystems. Surprisingly, within the 16S rRNA-based phylogenetic tree, hyperthermophiles occupy all the shortest and deepest branches closest to the root. Therefore, they appear to be the most primitive extant organisms. Most of them (the primary producers) are able to grow chemolithoautotrophically, using CO2 as sole carbon source and inorganic energy sources, suggesting a hyperthermophilic autotrophic common ancestor. They gain energy from various kinds of respiration. Molecular hydrogen and reduced sulfur compounds serve as electron donors while CO2, oxidized sulfur compounds, NO3- and O2 (only rarely) serve as electron acceptors. Growth demands of hyperthermophiles fit the scenario of a hot volcanism-dominated primitive Earth. Similar anaerobic chemolithoautotrophic hyperthermophiles, completely independent of a sun, could even exist on other planets provided that active volcanism and liquid water were present.

Anaerobiosis↗
PubMed1977

Reduction of adenylylsulfate and 3'-phosphoadenylylsulfate in phototrophic bacteria.

Extracts of 14 species of phototrophic bacteria, partly grown with different sulfur compounds, were tested for their ability to form volatile sulfur compounds from adenylylsulfate (APS) and 3'-phosphoadenylylsulfate (PAPS). The Rhodospirillum species showed marked activities with both APS and PAPS while the Rhodopseudomonas species seem to prefer PAPS. The Chromatiaceae exhibited the strongest activities with APS, whereas Chlorobium limicola had equally high activity with PAPS.

Adenine Nucleotides↗
PubMedDate not supplied

[Utilization and transformation of sulfur-containing compounds by hens].

In the experiments with 35S-labelled sodium sulfate, sulfate sulfur was found to be used for cysteine synthesis in hens. The 35S label was detected in hen's eggs as well, the subshell membranes possessing the highest specific radioactivity. A dependence of 35S incorporation on the ovule developmental stage was revealed. It was established that a shortage of sulfur-containing amino acids in hens' diet can be partially compensated by sodium sulfate sulfur, which influences the concentration of some metabolites.

Animal Nutritional Physiological Phenomena↗
PubMedDate not supplied

Effect of in situ composting on reducing offensive odors and volatile organic compounds in swineries.

Seven swine farms were studied to find out how the in situ composting system, compared to the slatted floor pit system, influences the concentration and occurrence of malodorous compounds. Ammonia concentrations were measured with diffusion tubes. Small molecular sulfur compounds were analyzed using laminated bags and a gas chromatograph with a FP-detector. All other volatile organic compounds were analyzed by gas chromatography/mass spectrometry with simultaneous sniffing of the eluted compounds. About 400 organic compounds were identified from the air samples, and 94 suspect odorous compounds are listed in the present article. The most intense and unpleasant odors were caused by p-cresol, carboxylic acids (C2-C7), and some ketones such as 3-hydroxy-2-butanone, 2,3-butanedione, and 2-butanone. Terpenes (alpha-pinene, beta-pinene, 3-carene, and limonene), which originate from sawdust, caused the main peaks in the chromatograms of compost swineries. In swine confinement buildings where the composting system was functioning properly, the concentration of sulfur compounds, and especially of carboxylic acids, ketones, and p-cresol, fell effectively. The use of sawdust as composting material caused elevated concentrations of terpenes in the ambient air. There was clearly less airborne ammonia and hydrogen sulfide in the well-functioning compost swineries than in the poorly functioning ones. Elevated hydrogen sulfide levels were measured during turning work, however. In one composting swinery, the hydrogen sulfide level was as high as 15 mg/m3 during turning work. All the other concentrations of odorous compounds did not exceed occupational exposure limit values, but several compounds exceeded the respective threshold odor concentrations.

Air Pollutants, Occupational↗
PubMed2006

Kinetics of Cisplatin and its monohydrated complex with sulfur-containing compounds designed for local otoprotective administration.

The anticancer drug cisplatin can cause permanent inner ear damage. We have determined the second-order degradation rate constant, k(Nu), of cisplatin and its more toxic monohydrated complex (MHC) in the presence of each of the sulfur-containing nucleophiles N-acetyl-l-cysteine, l-cysteine methyl ester, 1,3-dimethyl-2-thiourea, d-methionine, and thiosulfate, compounds that are under evaluation for local administration to prevent cisplatin-induced ototoxicity. MHC was isolated from a hydrolysis solution of cisplatin using liquid chromatography (LC). The degradations were evaluated by measuring the disappearance of MHC and cisplatin at 37 degrees C and pH 7.4 in the presence of each of the nucleophiles using LC and photometric detection. The k(Nu) of MHC and of cisplatin was 0.044 M(-1)sec(-1) and 0.012 M(-1)sec(-1) with N-acetyl-l-cysteine, 0.24 M(-1)sec(-1) and 0.067 M(-1)sec(-1) with l-cysteine methyl ester, 0.16 M(-1)sec(-1) and 0.074 M(-1)sec(-1) with 1,3-dimethyl-2-thiourea, 0.070 M(-1)sec(-1) and 0.069 M(-1)sec(-1) with d-methionine, and 3.9 M(-1)sec(-1) and 0.091 M(-1)sec(-1) with thiosulfate, respectively. Our results suggest that thiosulfate, as being the strongest nucleophile, is a promising candidate for local application in order to reduce the inner ear content of MHC and cisplatin. However, otoprotection is a multifactorial event, and it remains to be established how important nucleophilicity is for the effectiveness of the protecting agent.

Animals↗