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The kinetics of uptake of inorganic mercury as mercuric chloride by a variety of freshwater river sediment types typical of Ottawa River sediments were studied to determine the influence of mercury concentration in water, hydrodynamic effects, sediment depth, aerobic or anaerobic conditions, and two types of water. Uptake appears to depend strongly on concentration of mercury in water and water velocity, and not on sediment depth or water type. No significant difference in uptake rates was observed between aerobic and anaerobic conditions during the 10 days studied.

Equations and graphs were shown demonstrating the relation of the enlarged saprobic index S to mean values of BOD 5 . Two sets of constants had to be calculated, as there is an important break on the line (Fig. 3) dividing the aerobic and anaerobic environment. This break occurs near BOD 5 = 50 mg l −1 and S = 4·5.

1. 1. Oxygen consumption rate and critical oxygen partial pressure were measured in twenty-eight species of midwater crustaceans and two species of midwater fishes. 2. 2. The Pc's were compared to the environmental oxygens at which these species are found. This comparison indicates that all species, except the two parasites and the one diurnal vertical migrator, are able to regulate their QO2 to at least the lowest pO2 they encounter in nature (as low as 4 mm Hg O2 in some cases). The exceptions have considerable anaerobic abilities. 3. 3. The oxygen consumption rate of these species is shown to decline rapidly with increasing depth of occurrence and the factors involved are discussed.

The safe period of anoxic arrest of the heart is related to its individual metabolic activity rather than to a specific time interval. The capacity of the heart to produce energy through anaerobic metabolism, on which survival depends, has been assessed in this study by continuous monitoring of intramyocardial carbon dioxide tension (Pco2). Two groups of 12 dogs each were placed on total cardiopulmonary bypass at 38° C. and 28° C., respectively. Anoxic arrest of the heart was produced by cross-clamping of the ascending aorta and venting of the left ventricle. Intramyocardial Pco2 was measured by a mass spectrometer, and carbon dioxide accumulation curves were plotted. An initial period during which the Pco2 increased in a linear fashion was followed by a period during which the rate of rise gradually decreased until a plateau was reached. If the arrest was terminated at the transition point between these two periods, all hearts could be resuscitated. If the arrest was terminated when the carbon dioxide accumulation curve had reached a plateau, none of the hearts could be resuscitated. These results are given in the text. Our technique defines a point at which anoxic arrest can be safely terminated. This point can be significantly extended by reducing the metabolic activity of the heart by moderate hypothermia.

Rates of NO3- disappearance under anaerobic conditions, from six widely differing soils, gradually increased and then became relatively constant when glucose was added in increments supplying 0.04 to 1.5 mg of C/g of soil. Maximum rates of NO3- loss ranged from approximately 9.3 to 13.7 percent/hr. Increased production of NH4+ accompanied glucose additions in all soils. Results based on 13N-labeled Ca(NO3)2 showed that substantial amounts of NO3- were reduced to NH4+ after 4 hr of anaerobic incubation, and 15NH4+ continued to increase until all or most of the 15NO3- had been converted to NH4+, organic N, and gaseous forms (N2 and N2O). Results seriously challenge the prevalent view that denitrification accounts for essentially all NO3- dissimilation in anaerobic soils.

The activity of lactate dehydrogenase and fractions of this enzyme has been estimated in human large saphenous veins. Typical varicosities were compared in composition with normal veins from the same patients. The total LDH activity was significantly decreased in typical varicosities. Varicose veins further differed from macroscopically normal veins by a lower content of aerobic fractions of LDH and a higher content of anaerobic fractions. These results suggest that there is a disturbance in metabolism of the smooth muscle of the venous wall in varicosities which would make the diseased wall more dependent on anaerobic glycolysis than normal tissue.

The anaerobic digester is a common biological wastewater treatment process. A recently proposed fifth-order, nonlinear, dynamic model for the anaerobic digester has been shown to be qualitatively correct. Three methods of controlling the anaerobic digester are considered: base addition, organism recycle, and flow control. Feedback and feedforward controllers are designed for each of the control mechanisms, and a discrete adaptive predictive flow control algorithm is proposed. The control studies indicate that feedforward base addition control, in response to organic loading, is more effective and less expensive than feedback proportional base addition control. The predictive controller periodically computes optimum influent flow rate to the digester based on model response. This direct digital control method is adaptable to other wastewater treatment processes and offers flexible control objectives, allowing operational costs and quality of performance to be assigned weight factors, based on operational goals.

The biomechanics of overground running were compared before and after a month training period which comprised 16 thirty-minute sessions of short duration (5 seconds work, 10 seconds rest) high intensity (4.69 m/sec 20-25% grade) interval treadmill work. For the eight subjects filmed there were no significant changes in support and non support time, stride length or stride rate while running at 3.58 m/sec that could be attributed to the treadmill training regime. This training programme produced significant gains in aerobic and anaerobic metabolism but was not an effective developer of speed.

Summary The anaerobic formation of protoheme from added excess delta amino levulinic acid was markedly reduced if fumarate was omitted from an anaerobic incubation mixture containing resting suspensions of E. coli grown anaerobically on a medium containing fumarate. However, the formation of coproporphyrinogen did not require fumarate, suggesting a role for fumarate at some step between coproporphyrinogen and heme in the anaerobic heme biosynthetic pathway. The appearance of fluorescence during the anaerobic incubation of these cell suspensions was also dependent upon the presence of fumarate, suggesting that fumarate could anaerobically oxidize protoporphyrinogen to protoporphyrin. This was confirmed by demonstrating that fumarate could serve as an alternate electron acceptor to replace oxygen in the oxidation of chemically reduced protoporphyrinogen under anaerobic conditions inextracts of these cells. This was the first demonstration of the enzymatic oxidation of protoporphyrinogen to protoporphyrin by a physiological electron acceptor other than oxygen in any type of cell.

During the last several years we have been using anaerobic and aerobic propionic acid/hydrochloric (HCl) hydrolysis as an analytical tool. Our previous communication (1) showed that not only free peptides but also peptides made by the Merrifield procedure (2–4) and still attached to the resin could be hydrolyzed quantitatively in 2 hr at 130°C. This procedure compared favorably (1) with constant boiling HCl hydrolysis which requires initial removal of the peptides from the resin and takes 24 hr. This publication compares the results of 55 peptides, 1 11 free and 44 attached to resin, hydrolyzed aerobically with propionic acid/hydrochloric acid for 15 min at 150°C, 15 min at 160°C, and 2 hr at 130°C.

Microbial anaerobic metabolism was measured as dehydrogenase activity using 2,3,5-triphenyltetrazolium chloride. Dehydrogenase activity (DHA) per g dry sediment was correlated with adenosine triphosphate (ATP) per g dry sediment as determined by luciferin-luciferase reaction; both generally decreased with depth of sediment layer. The ratio DHA: ATP (ab-sorbance per mole ATP), however, increased significantly with depth of sediment layer. Dehydrogenase activity and oxygen debt of surface sediment and dissolved oxygen of bottom water were interrelated and all related to the depth of water; ATP content of the surface sediment had a similar but statistically insignificant trend as DHA. Data from conversion of ATP to organic carbon per m2 in the surface 4-cm layer at 11 stations showed a significant decrease in microbial biomass with increasing depth of water.

Selenomonas ruminantium is a nonsporeforming anaerobe that ferments carbohydrates primarily to lactate, propionate, acetate and CO 2 . H 2 production by this species has not been previously reported. We found, however, that some strains produce trace amounts of H 2 which can be detected by sensitive gas chromatographic procedures. H 2 production is increased markedly, in some cases almost 100-fold, when the selenomonads are co-cultured with methane-producing bacteria. Growth of the methane-producing bacteria depends on H 2 production by the selenomonads and the subsequent use of H 2 for the reduction of CO 2 to CH 4 . Although no free H 2 accumulates in the mixed cultures, the amount of H 2 formed by the selenomonads can be calculated from the amount of methane produced. These studies indicate that the conventional methods for measuring H 2 production by pure cultures do not provide an adequate estimate of an organism's potential for forming H 2 in an anaerobic ecosystem where H 2 is rapidly used, e.g., for formation of CH 4 .

Five anaerobic media were compared in a model blood culture system for their ability to recover small inocula of Gram-negative non-sporing anaerobes. Dehydrated cooked meat medium was the least effective; USP thioglycollate medium was the most effective isolation medium and is recommended for routine use. Freshly prepared cooked meat medium has the advantage of allowing prolonged survival of strains.

It is shown that the coleoptiles of rice grown under conditions of strict anaerobiosis possess the capacity to respire. The mitochondria of “anaerobic” coleoptiles contain the entire set of cytochromes typical of plant mitochondria. However, the amount of cytochromes is 2–3 times less than in “aerobic” coleoptiles. “Anaerobic” mitochondria are able to oxidize the substrates of the Krebs cycle and NADH. The respiratory activity of coleoptiles does not increase during anaerobic growth (from the 3rd to the 7th day). The neoformation of respiratory enzymes begins only after transferring “anaerobic” coleoptiles to aerobic conditions.

When embryos, or dorsal or ventral half-embryos, of Xenopus laevis are subjected to unilateral restriction of oxygen supply, the posterior end will always appear at the aerobic side, while the development of the anterior end, oriented towards the anaerobic side, will be partly suppressed. The shorter the time treatment lasts, the more normal the development will be. When the restriction of oxygen effects an inversion of the dorso-ventral polarity, development is retarded, otherwise not. Measurements of oxygen consumption show a substantial reduction in the experimental embryos, as compared with normal ones. The change in oxygen consumption in inverted embryos is delayed relative to non-inverted ones, but there is no significant difference in the total consumption of oxygen. Our results support the idea that the dorso-ventral polarity is associated with a gradient in oxygen consumption, and various kinds of evidence suggest that oxygen consumption is, in part, required for the formation of Ruffini’s flask-cells, responsible for the initiation of invagination. It is suggested that the basic mechanisms involved in the determination of the normal, and the inverted, dorso-ventral polarity are fundamentally different, the latter being in fact an induction of a new polarity.

The photosynthetic CO2 fixation by spinach leaf (Spinacia oleracea L. var. Kyoho) protoplasts was inhibited by substituting an atmosphere of N2 with one of either air (21% O2) or 100% O2. The inhibitory effect of 100% O2 was greater than that of air. The mode of inhibition by 100% O2 and air was competitive with respect to CO2; Ki(O2) value was 0.32 mM at pH 7 and 0.28 mM at pH 8.5 The labeling patterns of compounds in protoplasts exposed to 14CO2 in light after transferring them from N2 to O2 atmospheres were examined. There was no detectable 14CO2 incorporation into glycolate under anaerobic and O2 atmospheres; a more marked labeling of glycine occurred under an oxidative environment compared to that under the anaerobic condition, presumably because of a rapid transformation of glycolate to glycine in the protoplasts.

1. The activities of glycolysis and K-+ transport have been studied in slices of Morris hepatoma 3924A incubated under anaerobic conditions in the presence of different concentrations of glucose (1-50 mM). 2. Ouabain-sensitive net transport of K-+ was observed at all glucose concentrations greater than 1 mM; ouabain reduced the rate of glycolysis by about 25% at all glucose concentrations able to support ion transport. 3. The net entry of glucose into the intracellular phase was studied at varying glucose concentrations. The rate of glucose entry was similar to the rate of glucose utilisation by anaerobic glycolysis at medium concentrations of 10 mM and less, but exceeded the rate of glycolysis at 20 mM and above. 4. The glucose entry was not Na-+-dependent and was not inhibited by ouabain. 5. The results suggest (a) that the reduction in glycolytic activity caused by ouabain is not due to an inhibition of glucose transport and (b) that the glucose transport system of this poorly differentiated hepatoma has properties similar to that of normal liver.

A method for determining heat generation in isolated retinas by direct calorimetry is described and comparisons are made between the values thus determined and values obtained by indirect calorimetry. The heat production figures obtained by these two methods were significantly different and they correspond closely to values calculated from previously published biochemical data. Even though indirect calorimetry does provide a good estimated of heat produced from aerobic reactions it cannot be used to estimate the total heat production in isolated tissues such as the teleost retina which relies on anaerobic biochemical reactions to provide some 50–60% of its total energy needs. It is concluded that in future determinations of metabolic rates on isolated tissues, consideration of non-oxidative pathways be made before indirect calorimetry is pursued.

An apparatus is described for the rapid measurement and recording of methanogenic activity in anaerobic fermentations, and its application is demonstrated in the evaluation of the anaerobic contact process, using pear waste. The method is based on recording the rate of manometer liquid displacement in a Warburgtype vessel by means of optical sensors, appropriate electronic circuitry, and an event marking recorder or time-interval printer. Optimum conditions for measuring methanogenic activity included a pH of 6.7–6.9, a final phosphate buffer concentration of 0.07–015M, and formic and acetic acid contents of over 500 and 200 mg/liter, respectively. In comparisons of fermenter liquid and settled effluent, methanogenic activity can be assumed to be proportional to the number of methane formers present. The apparatus should be generally useful in recording rates of gas production or consumption.

1. Rates of reduction of a number of azo food dyes were measured in anaerobic cultures of Proteus vulgaris. The rates of colour loss were found to be zero order under conditions in which the concentration of viable cells remained constant.2. A significant increase in the rate of reduction followed the onset of cell mortality.3. The zero-order rates correlate with the redox potentials of the dyes. A mechanism consistent with these observations involves an extracellular nonenzymic reducing agent which acts as an electron shuttle between dye and cellular reducing enzymes.

Some aspects of anaerobic metabolism in the red and white (mosaic) muscles of the rainbow trout have been studied during environmental hypoxia. Evidence has been obtained for the operation of anaerobic pathways other than glycolysis, especially in the superficial red muscle. L-alanine and succinate were observed to accumulate as anaerobic endproducts in this tissue. Anaerobic glycolysis also increased significantly during hypoxia, but only in the white muscle. Glycogen stores were depleted by 70–85 % in both red and white muscle. Glucose increased in concentration in the red but not in the white muscle. In an attempt to understand some of the species differences in the susceptibility of fish to hypoxia the results of the present study have been compared with an earlier study on the carp (Johnston, 1975). The effect of death from hypoxia on the levels of muscle metabolites has also been studied.

Following observations that ethylene can occur in anaerobic or partially anaerobic soils at concentrations which can affect plant growth, shoot and root growth of barley plants, maintained in solution culture, were examined after long-term exposure of the roots to ethylene in air; the subsequent growth on transfer to a similar but ethylene-free environment was also studied. Both root and shoot dry weights were reduced slightly by the ethylene treatment; seminal root extension was inhibited greatly while lateral root growth was stimulated; absorption of ions and their transport from root to shoot within the plant was not affected. On transfer to an ethylene free environment the extension rate of the seminal axes increased markedly and was the greater the shorter the period of the preceding ethylene treatment; the extension of laterals initiated during the ethylene treatment was stimulated greatly but the growth of those formed subsequently was inhibited.

Glucose utilization, biosynthesis of fructose and citrate, and certain aspects of energy metabolism were studied in a homogeneous preparation of mating guinea pig seminal vesicle epithelium. Under aerobic conditions, ATP:ADP ratios between 6 and 7 were maintained attesting to the viability and metabolic integrity of the preparation. There were multiple differences between seminal vesicle epithelium and smooth muscle on comparison of concentrations of 19 different metabolites including the adenine nucleotides. In seminal vesicle, glycolysis was rapid under anaerobic conditions (approximately 25 mumol times g-1 times hour-1 during the first 3 min) and also occurred under aerobic conditions (approimately 5 mumol times g-1 times hour-1). Anaerobically, the concentration of fructose diphosphate increased 2-fold and that of fructose 6-phosphate decreased to one-third of control values, consistent with regulation at the level of phosphofructokinase. ATP and total adenine nucleotides decreased rapidly and, by 3 min, had attained steady state values of about one-third and one-half of control values, respectively. Under aerobic conditions, the rate of fructogenesis increased with increasing concentrations of added glucose, reaching maximum (3 mumol times g-1 times hour-1) at 8 to 10 mM glucose and half-maximum at 2 mM glucose. Simultaneously, sorbitol synthesis occurred at rates that were similarly influenced by the concentrations of added glucose. The highest rate of fructogenesis (6.5 mumol times g-1 times hour-1) occurred during aerobic incubation immediately after a period of anaerobic incubation: exogenous substrate was not required. This could be prevented by addition of D-glyceraldehyde which was converted to glycerol stoichiometrically because of its preferential (versus glucose) reduction by aldose reductase. Our data are consistent with the sorbitol pathway of Hers as the major route of fructose biosynthesis. The rate of citrate syntehsis increased with increasing concentrations of added pyruvate. The maximum rate (3.4 mumol times g-1 times hour-1) was achieved with 2 mM pyruvate. Added glucose failed to support citrate synthesis to the same extent as did added pyruvate. The highest rate of citrate synthesis (8.0 mumol times g-1 times hour-1) occurred simultaneously with the highest rate of fructogenesis (after the anaerobic-aerobic transition). Exogenous substrate was not required.

The sensitivity of three strains of anaerobic intestinal bacteria, Clostridium perfringens, Bacteroides fragilis , and Peptococcus magnus , to the differential effects of oxygen and adverse oxidation-reduction potential was measured. The multiplication of the three organisms was inhibited in the presence of oxygen whether the medium was at a negative oxidation-reduction potential (Eh of -50 mV), poised by the intermittent addition of dithiothreitol, or at a positive oxidation-reduction potential (Eh of near +500 mV). However, when these organisms were cultured in the absence of oxygen, no inhibition was observed, even when the oxidation-reduction potential was maintained at an average Eh of +325 mV by the addition of potassium ferricyanide. When the cultures were aerated, the growth patterns of the three organisms demonstrated different sensitivities to oxygen. P. magnus was found to be the most sensitive. After 2 h of aerobic incubation, no viable organisms could be detected. B. fragilis was intermediately sensitive to oxygen with no viable organisms detected after 5 h of aerobic incubation. C. perfringens was the least sensitive. Under conditions of aerobic incubation, viable organisms survived for 10 h. During the experiments with Clostridium , no spores were observed by spore staining.

When washed spleen slices from fed rats are incubated with 3 mm-[U-14C]glucose, the rate of glucose utilization (46.2 mumol/h per g dry wt.) is sufficient to account, theoretically, for 80% of the O2 consumption. Measurement of net lactate production, however, and the fate of the radioactive carbon, indicates that the contribution of glucose to the respiratory fuel of the tissue is only 25-30% whereas 60-70% of the glucose utilized is converted into lactate. At saturating glucose concentrations (above 5 mm) its contribution to the respiratory fuel of the slice is increased to a maximum value of 34-39%. Only 2% of the glucose utilized is metabolized via the oxidative steps of the pentose phosphate pathway. Starvation for 72 h marginally increases both the rate of glucose utilization (by 21%) and its net contribution to the respiratory fuel (by 29%). Insulin, glucagon, adrenaline and adenosine 3′:5′-cyclic monophosphate have no significant effect on either the rate of glucose utilization or on the pattern of radioactive isotope distribution. The uptake of glucose is increased by only 20%, whereas the production of lactate doubles when slices are incubated under anaerobic conditions. In assessing the suitability of spleen slices for metabolic studies, the only serious major perturbation, compared with the freeze-clamped organ, is an elevated mitochondrial [NAD+]/[NADH] ratio (connected with increased endogenous NH3 production) that is partially restored to normal values on incubation with glucose. Equal proportions of erythrocytes and leucocytes are found in the washed spleen slice. Metabolic contributions of the constituent cell populations in the washed slice are calculated and it is concluded that lymphocytes account for the major part of the glycolytic metabolism (80-90%), whereas the contribution of erythrocytes is insignificant.

The metabolic states of various tissues of newborn rabbits were studied before and after periods of ischemia of 5–40 min. The contents of substances of the energy distributing adenylic acid-creatine phosphate system as well as glycogen, glucose and lactate were determined and the results are discussed in comparison with the well-known values from ischemic tissues of adult rabbits. The preservation of high energy phosphates as well as the rate of glycolytic energy production during the course of ischemia was quite identical in the myocardium of newborns and adults in contrast to the different ability of newborn and adult rabbits to maintain circulation in anaerobic conditions. In the central nervous system the ATP contents decreased to very low levels within a few minutes in both groups although the glycolytic energy production was rather different. But the larger amounts of adenine nucleotides present in the newborns at any time of ischemia indicate a better chance of postischemic recovery. In the livers and the kidneys of the newborns higher rates of glycolytic energy production led to better preservation of the energy-rich substances while in skeletal muscle and the lung only slight differences occurred between newborns and adults.

Three patients with Bacteroidaceae bacteremia and disseminated intravascular coagulation (DIC) are described. The association of DIC with this anaerobic infection has been infrequently reported. Septic shock due to Bacteroidaceae appears to involve endotoxin as in aerobic gram-negative bacillary sepsis. Similarly, endotoxin may be the trigger mechanism for initiating DIC in both aerobic and anaerobic gram-negative bacillary sepsis.

Artificial recharge basins or spreading sites commonly exhibit reductions in infiltration rates after prolonged periods of submergence. This loss in infiltration rate has often been shown to be associated with a large population of anaerobic or facultative anaerobic bacteria in the material underlying the basin floor. An artificial recharge experiment in a spreading basin at Lubbock, Texas, showed a significant change in the chemical quality of recharged water that was associated with the growth of anaerobic bacteria. Sulfate-reducing bacteria reduced the sulfate concentration of the recharge water at this location by 80 mg/l. The bicarbonate concentration was increased by more than 150 mg/l, and the pH decreased 1 unit during the same time period. The change in chemical quality occurred suddenly and corresponded to a dramatic decrease in the infiltration rate in the basin. These observations on the chemical changes in recharged water make it possible to differentiate between anaerobic bacteria and other causes of reduced hydraulic conductivity in this recharge basin. The anaerobic conditions appear to start at depth and work toward the surface, thereby suggesting a process that involves adsorption of organic material and consumption of dissolved oxygen with depth.

Pimaricin and nystatin, two antifungal agents, inhibited endogenous respiration and. anaerobic and anaerobic utilization of sugars by Kluyveromyces fragilis. Three sugars, lactose, glucose, and were metabolized by a somewhat similar process as judged by the extent of inhibition caused by the antifungals, both aerobically and anaerobically. The degree of inhibition by the antifungals was more pronounced under anaerobic conditions. There existed a direct, but not proportional, relationship between concentration of antifungals and extent of inhibition. Nystatin impaired carbohydrate metabolism slightly more than did pimaricin. Also, K. fragilis contained lactase which was found to be a constitutive enzyme and was inhibited by the two antifungal agents.

1. The design and procedure for use of an all-glass incubation flask which facilitates the production and maintenance of an anaerobic environment suitable for the study of drug metabolism by intestinal microflora is described. 2. Evaluation was based on monitoring available oxygen with an oxygen electrode. 3. Removal of air by the combination of replacement with hydrogen, a room temperature catalyst and a fluching technique, produced low oxygen levels comparable to vacuum systems without the need for adverse pressure changes.

The Bristol, Virginia Division of Dairymen, Inc. is a storage and transfer operation for raw milk. As production increased and effluent quality regulations become more stringent, waste treatment progressed from land irrigation, to a two-stage biological system to the present four-stage biological system including: (a) full mixed anaerobic; (b) facultative-high rate trickling filter and non solids controlled aeration; (c) quiescent anaerobic; and (d) facultative-high rate trickling filter and activated sludge. Treatment efficiencies were

Following a lag of 3 to 18 h, acetylene reduction in mannitol-amended sand systems proceeded at approximately constant and high rates for periods up to 4 days. Carbon dioxide production and O2 consumption were low in these systems in comparison to similar systems additionally amended with ammonium, indicating N-limitation of growth in the former. Thus, long-term acetylene assays of mannitol-amended sand and suspensions from the sand incubated at various partial pressures of oxygen could be used to characterize the O2-sensitivity of the N2-fixing bacterial population as a whole, in batch-type systems with a minimal degree of enrichment or change in pO2 during the course of the assays. Results of various studies suggested that aerobic or microaerophilic N2-fixing bacteria were absent or scarce in the sand, and that nitrogenase activity occurring in aerobically incubated systems occurred in anaerobic microenvironments. Hydrogen stimulated acetylene-reducing activity, but the time course differed from that of mannitol-supported activity, and proceeded with shorter lags in systems incubated at 0.2 and 0.05 atm O2 than in systems incubated anaerobically. Efficiency of N2 fixation [C2H2] increased with decreasing initial mannitol concentration. For sand washed with seawater to remove native combined inorganic nitrogen, and amended with 0.015% mannitol, 374 μmoles added NH4-N/kg wet sand caused almost complete repression of nitrogenase activity, while concentrations as low as 12 μmoles added NH4-N/kg wet sand appeared to cause at least partial repression of nitrogenase activity. Some implications of these results for the existence of anaerobic microenvironments in the cavities of skeletal carbonates, and for N2-fixation in the seagrass rhizosphere are discussed.

Biological degradation of synthetic detergents and commercial detergents was examined under various condition. By incubation with domestic sewage at 30°, 20 ppm of linear alkyl benzenesulfonate (LAS), which is degraded easily in contrast to alkyl benzenesulfonate (ABS), was consumed aerobically to the extent of about 50% after 7 days but to a slight extent under anaerobic condition. On the other hand, it was observed that higher fatty acid sulfate was easily biodegraded under both aerobic and anaerobic condition for 1 day. Biodegradation of LAS was delayed slightly in the presence of nutrients. Detergent-grown cells separated from domestic sewage showed two optimal peaks to 2, 3, 5-triphenyltetrazolium chloride (TTC) reduction activities at pH 7.0 and 8.5.

The progressive effects of aerobic starvation on endogenous and ethanol-linked respiration and pyridine nucleotide reduction have been studied in the yeast Saccharomyces cerevisiae. Three distinct phases of pyridine nucleotide reduction were observed when ethanol was added to unstarved yeast: an initial phase of rapid reduction and accelerating respiration (A); a steady-state phase of reduction with maximal respiration (B); a final phase of rapid reduction at anaerobiosis (C). During the first 5 hr of aeration, the steady-state Phase B was replaced by a phase of slow pyridine nucleotide reduction, while Phases A and C were unaffected. During this period, both endogenous pyridine nucleotide reduction and endogenous respiration decreased sharply. Between 5 and 22 hr of aeration, the endogenous level of reduced pyridine nucleotide declined further, while endogenous respiration remained unchanged. Concurrently, the extent of the Phase A reduction doubled. The addition of ethanol to aerobic, unstarved yeast stimulated a rapid pyridine nucleotide reduction, with further reduction occurring at anaerobiosis. Under anaerobic conditions, the addition of ethanol to unstarved yeast caused little further reduction of pyridine nucleotide. Two hours of starvation decreased the extent of the endogenously supported anaerobic reduction and correspondingly increased the ethanol-induced reduction. These results suggest that, in unstarved yeast, reducing equivalents derived from ethanol under aerobic conditions and those derived from endogenous carbohydrate under anaerobic conditions have access to the same pool of pyridine nucleotide. With starvation, this pool becomes accessible to ethanol-derived (or ethanol-mobilized) reducing equivalents under anaerobic conditions.

A device is described and evaluated for the anaerobic transport of clinical specimens. The device limits the amount of oxygen entering with the sample to a maximum of 2%, which is rapidly removed by reacting with hydrogen in the presence of a palladium catalyst. The viability on swabs of 12 species of anaerobes, four strains of facultative anaerobes and a strain of Pseudomonas aeruginosa, was maintained during the length of the tests (24 or 48 h). The results demonstrated that this device protected even the more oxygen-sensitive clinical anaerobes from death due to oxygen exposure. This device can be used for swabs as well as for anaerobic collection and liquid and solid specimens.

We investigated the effects of high temperature treatment (40°C three weeks) on dormant rice seeds of Hadsaduri (Oryza sativa cv.) which was known as a variety of deep dormancy and results obtained are summarized as follows; 1. The seed of which dormancy was broken by high temperature treatment could germinate under both aerobic and anaerobic conditions, whereas dormant seed could not germinate under the anaerobic condition. 2. Warburg manometric techniques were used for the determination of respiratory gas exchange. In the case of non-dormant seeds, the amount of released carbon dioxide always exceeded that of oxygen uptake. Whereas the dormant seeds showed nearly the same amount of oxygen uptake and carbon dioxide release. 3. Determination of ethyl alcohol was carried out by gas chromatography. Non-dormant seeds usually produced more amount of ethyl alcohol than dormant seeds. When both dormant and non-dormant seeds were incubated under nitrogen gas at 30°C, the same tendency as above was observed. 4. When non-dormant seeds were co-treated with sodium iodoacetate, which was known as one of the inhibitors of enzyme SH group, at 5mM and 10mM concentrations, the production of ethyl alcohol was inhibited. Germination of hulled rice of non-dormant seeds was not affected up to the concentraton to 10mM under aerobic condition, but almost completely inhibited at 5mM under submerged condition. From the facts described above, it might be possible to consider that the dormant rice seed had the aerobic respiratory pathway but had not an active anaerobic respiratory pathway sufficient for germination. Effects of high temperature treatment on breaking the dormancy of rice seed may be attributed to the activation of anaerobic respiration.

Coproporphyrinogenase was isolated from mitochondrial extracts of Saccharomyces cerevisiae following mechanical disruption. The enzyme was purified 150-fold by a procedure involving ion exchange chromatography and gel filtration. The molecular weight of the enzyme was 75,000 ± 7,500. The purified enzyme catalyzed the conversion of coproporphyrinogen III to protoporphyrinogen IX under both aerobic and anaerobic conditions. In the presence of air, the conversion was not dependent upon the presence of an exogenous hydrogen acceptor or other cofactors. Under anaerobic conditions, however, coproporphyrinogenase had an absolute requirement for divalent metal ion, ATP, and l-methionine. NAD+ or NADP+ was required as an electron acceptor, the latter being more effective. A pH of 7.6 was optimal for both the aerobic and anaerobic reactions. Apparent Km values of 3.2 x 10-5 m and 2.6 x 10-5 m were determined for the aerobic and anaerobic reactions, respectively. In the presence of high salt concentrations, chelating agents, sulfhydryl reactive compounds, or GSSG both the aerobic and anaerobic coproporphyrinogenase activities were inhibited. Anaerobic activity was also inhibited in the presence of 5 mm GSH or l-ethionine, but neither of these compounds affected the aerobic enzyme activity. Both the aerobic and anaerobic coproporphyrinogenase activities were insensitive to FAD, FMN, 2,4-dinitrophenol, and cyanide.

The rate constant-pH profile of the rate of sulfite-induced disappearance of epinephrine from an aqueous solution under anaerobic conditions was determined at 81 degrees in the 3.63-5.00 pH range at the ionic strength of 0.2. The profile shows a linear relationship with a positive slope. The anaerobic rate shows buffer catalysis above pH 4.4 Metabisulfite was found to be more catalytic than either bisulfite or acetone bisulfite. The concentration of epinephrine used was 5.5 times 10- minus 5 mole/liter.

Studies with artificially inoculated fresh beef showed that lactobacilli markedly restrict the growth of Microbacterium thermosphactum when the beef is vacuum-packaged. High concentrations of carbon dioxide (up to 75%) had little effect on the growth of M. thermosphactum under either aerobic or anaerobic conditions. Tests were made with samples of lean beef inoculated with pure cultures of lactobacilli and (or) M. thermosphactum and stored unpackaged in air, in air enriched with carbon dioxide, in nitrogen – carbon dioxide mixtures, or vacuum-packaged as in commercial practice. On vacuum-packaged meat, growth of M. thermosphactum was extensive in the absence of lactobacilli, but was restricted in the presence of lactobacilli. On unpackaged meat (i.e. stored in air) this inhibition did not occur, showing that anaerobic conditions are necessary for it to take place. These results show the importance of lactobacilli on the storage life of vacuum-packaged fresh beef.

SUMMARY The effects of exercise of different intensities on blood concentrations of glucose, lactate, pyruvate, free fatty acids and glycerol were studied in a group of clinically normal horses. Blood lactate, pyruvate and lactate/pyruvate ratio increased during exercise, particularly during galloping. These changes occurred within the first 12–15 seconds of exercise indicating that anaerobic metabolic pathways are brought into use very quickly in the strenuously exercising horse. Since blood glycerol levels were significantly increased during exercise body lipids were also mobilised. At the same time, free fatty acid levels increased during cantering but decreased during galloping indicating increased fat oxidation during strenuous exercise. It was concluded that both lipids and carbohydrates are as important energy sources in the exercising horse as in other species. RESUME L'action de l'exercice sur les concentrations sanguines de glucose, lactate, pyruvate, acides gras et glycerol fut etudiee chez des chevaux cliniquement normaux. Le lactate, le pyruvate et la rapport lactate/pyruvate montrerent des valeurs croissant avec l'exercice, avec le galop en particulier. Ces phenomenes surgissant durant les 12–15 premieres secondes indiquent que des processus metaboliques anaerobies s'installent tres rapidement lors d'un effort intense. Comme le taux sanguin du glycerol le taux des lipides fut egalement accru. Les acides gras non satures s'eleverent durant le canter mais leur niveau fut trouve decroissant durant le galop, ce qui indiquerait une oxydation accrue des graisses durant un effort intense. On pense que les sucres et les lipides representet des sources importantes d'energie durant l'effort chez le cheval comme dans les autres especes. ZUSAMMENFASSUNG Die Auswirkungen korperlicher Bewegung verschiedener Intensitat auf die Blutkonzentrationen von Glukose Laktat, Pyruvat, freie Fettsauren und Glycerin wurden bei einer Gruppe klinisch gesunder Pferde untersucht. Laktat-, Pyruvat-Konzentrationen und das Verhaltnis Laktat/Pyruvat stiegen wahrend der Bewegung an, besonders wahrend Galopparbeit. Diese Veranderungen zeigten sich innerhalb der ersten 12–15 Sekunden der Arbeit, was darauf hindeutet, dass anaerobe Stoff-wechselvorgange bei korperlicher Arbeit sofort zu funktionieren beginnen. Der signifikante Anstieg der Blutglycerinspiegel weist die Mobilisation der Korperfette bei korperlicher Arbeit nach. Die freien Fettsauren stiegen an wahrend des Kanters, fielen aber ab bei schneller Galopparbeit. Dieser Befund wird mit der erhohten Fettoxydation bei strenger Arbeit erklart. Es wird der Schluss gezogen, dass sowohl Lipide als auch Kohlehydrate beim Pferd eine ebenso grosse Rolle als Energiequellen spielen wie bei anderen Species.

Some of the metabolic and biochemical characteristics of 105 organisms isolated at 4° from meat matured in vacuo at 0–2° for 0–9 weeks were studied. Proteolysis was noted in Pseudomonas spp., Achromobacter spp. and Gram negative, fermentative organisms, mainly in aerobic and low oxygen environments. Fewer organisms hydrolysed beef fat than hydrolysed tributyrin. While representatives of most of the major groups of organisms dissimilated mono- and di-saccharides, more complex carbohydrates were less readily attacked. Only Gram negative, fermentative organisms showed decarboxylase activity on amino acids. There is evidence that Pseudomonas spp. can survive in an anaerobic environment, although their metabolism is less vigorous.

Sixteen strains of 11 facultatively anaerobic species of the genus Bacillus were tested for their ability to sporulate anaerobically on common laboratory media. Reliable data depended on a method providing anaerobic conditions quickly. Bacillus macerans (one strain tested) and B. polymyxa (two out of two strains tested) sporulated anaerobically without added nitrate. But B. licheniformis (one out of two strains tested) required nitrate for "anaerobic" sporulation. Anaerobic sporulation of B. macerans and B. polymyxa on potato extract agar was inhibited by nitrate.

Ethylene is microbially decomposed in aerobic soil conditions faster than it is produced in anaerobic soils. The organisms responsible form only a small part of the soil population and their activity is slowed by concentrations of carbon dioxide greater than five per cent.

Up to 90% of the gamma-Hexachlorocyclohexane (gamma-HCH) applied to an anaerobic mixed bacterial flora enriched from an arable soil were degraded within 4-5 days. Degradation resulted in a rapid release of chloride and in formation of chlorine-free volatile metabolites. CO2 formation from the molecule was not detected. Investigations with 14C/3H- and 36Cl/3H double-labelled gamma-HCH indicated that the release of Cl and H did not occur in the ratio of 1:1. More Cl than H was split off. The volatile compounds contained more 14C than 3H. Gas chromatographic studies also showed the rapid decrease of gamma-HCH and the formation of several metabolities. gamma-Pentachlorocyclohexene was nto detected. Increasing O2-contents in the gas phase of cultures resulted in decreases of the compound's degradation. Release of chloride and of volatile metabolites were observed with O2 contents in the gas phase up to 5%. alpha-HCH was also, but more slowly as with gamma-HCH, degraded by the anaerobic mixed flora. Chloride was released and volatile, chlorine-free metabolites were found.

A submodel for anaerobic mud-water exchange of phosphate is obtained from experiments in the laboratory. Phosphorus in the sediment can be divided into exchangeable and non-exchangeable phosphorus. The exchangeable phosphorus is decomposed in accordance with a first-order reaction. The phosphorus moves, after the decomposition process, from the interstitial water to the water phase, in accordance with a diffusion expression. The yearly increase of the sediment was determined by means of the lead concentration as a function of the depth.

Formation of ATP during aerobic respiration and denitrification was determined inPseudomonas denitrificans. In the intact cell system, the ATP formation associated with denitrification was almost the same as that associated with aerobic respiration when lactate was used as an electron donor. The ATP formation was inhibited by KCN, NaN3 and DNP. No phosphate uptake occurred when NH2OH, DMPD or TMPD was used as an electron donor, although the production of N2O, N2 or NO from nitrite was accelerated under anaerobic conditions. In the cell-free system, the ATP formation was also demonstrated using an ATP trapping system and lactate as a substrate. The effects of inhibitors were almost the same as those observed with the intact cells. DMPD or TMPD together with ascorbate promoted the ATP formation during aerobic oxidation by the cell-free system whereas no stimulation of ATP formation was detected during denitrification.