The influence of EDTA on the composition of alginate synthesized by Azotobacter vinelandii

1. During an investigation of the physiology of Azotobacter vinelandii with particular reference to polysaccharide formation, a suitable medium which was precipitate-free was developed by adding EDTA at a concentration of 50 mg/l to a basal medium containing one of eight different carbohydrates as sole carbon source.
2. Acetylated alginate was always produced by the organism when cultured under defined conditions, regardless of the carbohydrate source incorporated in the basal medium.
3. When EDTA was added to the medium, the bacteria produced acetylated polyuronides with a preponderance of mannuronic acid residues.
4. A comparison of the infrared spectra of the alginate produced by Azotobacter vinelandii and the affect of EDTA upon the mannuronic acid/guluronic acid ratios of the alginate are reported.

     

Fumarate reduction inProteus mirabilis

1. Proteus mirabilis formed fumarate reductase under anaerobic growth conditions. The formation of this reductase was repressed under conditions of growth during which electron transport to oxygen or to nitrate is possible. In two of three tested chlorateresistant mutant strains of the wild type, fumarate reductase appeared to be affected.
2. Cytoplasmic membrane suspensions isolated from anaerobically grownP. mirabilis oxidized formate and NADH with oxygen and with fumarate, too.
3. Spectral investigation of the cytoplasmic membrane preparation revealed the presence of (probably at least two types of) cytochromeb, cytochromea ₁ and cytochromed. Cytochromeb was reduced by NADH as well as by formate to approximately 80%.
4. 2-n-Heptyl-4-hydroxyquinoline-N-oxide and antimycin A inhibited oxidation of both formate and NADH by oxygen and fumarate. Both inhibitors increased the level of the formate/oxygen steady state and the formate/fumarate steady state.
5. The site of inhibition of the respiratory activity by both HQNO and antimycin A was located at the oxidation side of cytochromeb.
6. The effect of ultraviolet-irradiation of cytoplasmic membrane suspensions on oxidation/reduction phenomena suggested that the role of menaquinone is more exclusive in the formate/fumarate pathway than in the electron transport route to oxygen.
7. Finally, the conclusion has been drawn that the preferential route for electron transport from formate and from NADH to fumarate (and to oxygen) includes cytochromeb as a directly involved carrier. A hypothetical scheme for the electron transport in anaerobically grownP. mirabilis is presented.

     

ATP-driven succinate oxidation in the catabolism of Desulfuromonas acetoxidans

The oxidation of succinate with elemental sulphur in Desulfuromonas acetoxidans was investigated using a membrane preparation of this bacterium. The following results were obtained:

1. The preparation catalyzed the oxidation of succinate with sulphur and NAD. These reactions were dependent on ATP and were abolished by the presence of protonophores or dicyclohexylcarbodiimide (DCCD).
2. The membrane preparation also catalyzed the reduction of fumarate with H₂S or with NADH. These activities were not dependent on ATP and were not affected by protonophores or DCCD.
3. By extraction-reincorporation experiments it could be shown that menaquinone is involved in electron transport between H₂S and fumarate and between NADH and fumarate.
4. The membrane fraction catalyzed the reduction of the water-soluble menaquinone-analogue dimethylnaphthoquinone (DMN) by succinate, H₂S, or NADH, and the oxidation of DMNH₂ by fumarate. These activities were not dependent on the presence of menaquinone and were not influenced by ATP.
5. The activities involving succinate oxidation or fumarate reduction were similarly sensitive to 2(n-nonyl)-4-hydroxyquinoline-N-oxide, while H₂S and NADH oxidation by DMN were not affected by the inhibitor.

It is concluded that the catabolism of D. acetoxidans involves the energy-driven oxidation of succinate with elemental sulphur or NAD as electron acceptors and that menaquinone is a component of the electron transport chain catalyzing these reactions.     

Interaction between the antimicrobial peptide Aurein 1.2 dimer and mannans

We have previously described the structure and the ability of a dimeric analog of the antimicrobial peptide Aurein 1.2 to aggregate Candida albicans. In this study, circular dichroism and fluorescence spectroscopy data showed that this aggregation is related to the interaction between the peptide and mannans, the main component of yeast cell wall. In this context, we propose a model in which dimers interact with the polysaccharide leading to cells aggregation.     

Context-dependent stuttering

Bei einer Untersuchung des Stotterns in der deutschen Umgangssprache machten wir folgende Beobachtungen:

1. Das gestotterte Phonem wird häufig von einem identischen Phonem begleitet (definiert als das ?induzierende Phonem“) welches sowohl vor wie nach dem gestotterten Phonem auftreten kann.
2. Gewöhnlich folgte das induzierende Phonem dem gestotterten Phonem.
3. Der Abstand zwischen induzierendem und gestottertem Phonem war geringer als bei Zufälligkeit zu erwarten.
4. Induzierende und gestotterte Phoneme befanden sich gewöhnlich in identischen Silbenpositionen.
5. Gestotterte Phoneme traten in der Regel bei betonten Silben auf.

Um diese Beobachtungen zu erklären erschienen uns drei Annahmen erforderlich:

1. Sprach-Output ist hierarchisch bestimmt. Silben und Phoneme sind Glieder in dieser Hierarchie.
2. Unterschwellige Erregbarkeit ist in dieser Hierarchie stärker bei betonten als bei unbetonten motorischen Programmen.
3. Ähnliche Programme (sowohl auf Silbenals auch Phonemniveau) inhibieren einander.

Diese Annahme gibt zugleich eine mögliche Erklärung für Blockierung und Längung — Phänomene, die ebenfalls in der Sprache von Stotterern auftreten. Unsere Beobachtungen bieten also eine mögliche Lösung für das Rätsel des Stotterns.     

Counterimmunoelectrophoresis as a routine mycoserological procedure

Counterimmunoelectrophoresis (CIE) has been compared in a diagnostic laboratory with agar gel double diffusion (DD) as a routine procedure for detection of antibodies to pathogenic and allergenic fungi and actinomycetes. It was shown to be of particular value in detecting antibodies to Aspergillus fumigatus. Thus 72 of 106 sera in which precipitins were detected were positive by CIE alone. Some sera were positive only by CIE to antigens prepared from Histoplasma capsulatum, Allescheria boydii, Candida albicans and C. parapsilosis.     

Candidaemia Observed at a University Hospital in Milan (Northern Italy) and Review of Published Studies from 2010 to 2014

Background

Candida species represent the fourth leading cause of nosocomial bloodstream infections (BSI) worldwide. However, candidaemia rates and species involved vary geographically.

Objectives

To evaluate the epidemiological pattern, risk factors for mortality and antifungal therapy of Candida BSI over a 5-year period (2008–2012) in a university hospital in northern Italy together with a review of the recent literature concerning candidaemia.

Methods

A retrospective cohort study cross-linked with microbiology database was performed.

Results

A total of 89 Candida BSI were identified in 42 males (47 %) and 47 females (52.8 %). The median age was 69 years (interquartile range 55–78) with 61.8 % of patients being older than 65 years. Considering all hospitalized patients, the overall incidence rate of candidaemia increased significantly from 2008 to 2012 (from 0.4 to 1.68 episodes per 10,000 patient/days) (p = 0.0001) with a mean linear increase in 5 new cases per year. Candida albicans was the predominant species isolated (64 %) followed by C. glabrata (19.1 %). The latter species was observed with significantly higher frequency in Internal Medicine and Intensive Care Units (ICU). In-hospital crude mortality was 41.6 %.

Conclusions

Candidaemia is an increasing BSI in our university hospital, in accordance with that observed in northern Italy, and it is still associated with high in-hospital crude mortality.     

Growth requirements of blue-green algae under blue light conditions

1. Growth requirements of blue-green algae containing only the c-phycocyanin + chlorophyll a pigment system have been studied under blue light (380–540 nm) which approximates light conditions existing in subsurface waters in nature.
2. While a few species were capable of very slow photosynthetic growth on minimal medium with NO₃ ^- as nitrogen source, most species were dependent on organic compounds for comparable growth under this condition. Some organisms did quite well with only Casamino Acids as a supplement, others did well with only glucose. One species, Agmenellum quadruplicatum strain PR-6, grew only when glucose and Casamino Acids were supplied simultaneously.
3. Inhibitory effects of blue light on CO₂ fixation and nitrogen metabolism are noted as possible explanations of these responses.

     

The distribution of aquatic oligochaetes in the south and eastern Mediterranean area

On the basis of the material collected in Morocco, Algeria, Tunisia, Lebanon, Syria and Turkey, and published data, mainly on Israel and Egypt, we try to establish a synthesis of the geographical distribution of the poorly known fauna of the South and Eastern Mediterranean basin. A first analysis shows that the fauna of this region is characterized by a high number of species with a widespread distribution (cosmopolite, holarctic, palaearctic ...) and therefore, with great affinities with the European fauna. Nevertheless, three distinct communities can be distinguished:

- The south western basin (North Africa; Morocco, Algeria, Tunisia), where the community is very poor, and which shows great affinities with south European, but none with the Ethiopian region;

- The south eastern basin (Egypt), with some species of African origin;

- The eastern basin (Near East, mainly Lebanon and Israel) with a very diversified community, partly due to its geographical situation, and partly due to a more intensive collecting pressure. This community includes a group of species with more eastern affinities (East Siberian ...), but none typically Ethiopian or exclusively Sino-Indian.

     

Stability and zymogenic nature of chitin synthase fromCandida albicans

Chitin synthase preparations from both yeast and mycelialCandida albicans were chiefly in a zymogenic form, activatable by trypsin treatment. This was especially marked for preparations that had been solubilized with digitonin treatment. Endogenous activation of chitin synthase zymogen was observed over many days in preparations stored in glycerol (33%, wt/v) at?12°C and over many hours in preparations stored at 30°C. Gel chromatography of enzyme preparations suggested that zymogen was preferentially retarded on the columm matrices in comparison with active enzyme.     

Water quality studies on Buckingham Canal (Madras,India) — A discriminant analysis

Stepwise multiple discriminant analysis was applied to a two year water quality monitoring study of the Buckingham Canal at Madras, India. The variables were divided into

1. physical and chemical
2. pollutants; and
3. biological

to test which group is efficient in discriminating stations which differ in water quality. Biological variables obtained higher loadings on the discriminant functions than the other two groups. The derived discriminant functions were tested for their discriminating power through the classification phase with the same raw data. The \lsHit and Misses\rs tables of classification indicate that 81.660% of the samples were correctly classified by the biological variables, against only 46.660% of the samples in the case of physical and chemical variables and 48.33% in the case of pollutants.     

Properties of a motor output system involved in the optomotor response in flies

1. The optomotor response of tethered flying houseflies (Musca domestica) has been studied at the level of the neural output which controls the activities of some non-fibrillar flight muscles (N-muscles).-a) During visually induced turning responses in a given direction some N-muscles on the right side of the thorax are synergistically active together with other N-muscles on the left side of the thorax. The same muscles are inactive during turning reactions in the opposite direction while the corresponding antagonists are now active (synopsis in Table 1).-b) The response activities of the N-mussles show a considerable variation during the course of time in spite of constant visual input.-c) There is a strong tendency for N-muscle spikes to be phase-locked with respect to the wingbeat period.-d) The findings obtained fromMusca are in accordance with the corresponding results obtained fromCalliphora (Heide, 1971b).
2. TheN-muscle activities have also been investigated in tethered flying blowflies (Calliphora erythrocephala) which tried to yaw spontaneously with both wings beating. In spontaneous left (right) turn reactions the features of the observed neural output are nearly identical with the features of the motor output showing up during visually induced left (right) turn reactions.-A different motor output pattern has been found in flies with only one wing beating.
3. The wingbeat synchronous rhythm observed in spike trains from activeN-muscles is produced in the thorax without the participation of higher stages of the fly's CNS. On the other hand no distinct rhythms can be found in spike trains fromN-muscles of non-flying flies when their motoneurons are artificially activated by non-rhythmic stimuli. Afferent information from thoracic sense organs seems to be essential for the production of the rhythm observed during flight.
4. The results about the production of the wingbeat synchronous rhythm in spike trains fromN-muscles suggest that the information derived from the motion detectors only acts to gate the output needed to achieve yaw-turn reactions. The strength of the influence of signals from the motion detectors on the output producing system can be modified by the animals “state of excitement”.
5. A model is presented which summarizes some features of information processing in the output systems supplying theN-muscles of flies. Available physiological data are discussed in relation to the model.

     

Life-cycles of some invertebrate taxa in a small pond together with changes in their numbers over a period of three years

1. Monthly quantitative samples of the invertebrate fauna (except Protozoa) in a small pond were taken over a period of three years. During one year, insect emergence traps were in operation. Water temperatures were recorded during the investigation.
2. The most abundant organisms in the pond were Phaenocora typhlops, Limnodrilus hoffmeisteri and Chaoborus crystallinus. Certain species of Micro-Crustacea and Chironomidae were also abundant but these groups have been dealt with elsewhere (see p. 66). Dendrocoelum lacteum, Polycelis nigra, Helobdella stagnalis, Lumbriculus aariegatus, Tubifex tubifex, Planorbis complanatus, and Asellus meridianus also occurred in considerable though lower numbers; other species occurred in low numbers.
3. The life-cycles and changes in numbers of the more numerous species are considered. The life-histories of D. lacteum, P. nigra, H. stagnalis, P. complanatus, A. meridianus are in agreement with published information. P. typhlops is seasonal in occurrence, being active from May to Sept. inclusive. Times of emergence of adults of various insect species agree with information available in the literature.
4. The life-cycle of L. hoffmeisteri in the pond is as follows: young worms hatch in spring/summer and form the bulk of the population from April to July/Aug; they mature from Aug. onwards and breeding starts in earnest from Feb./March. The life-cycle of T. tubifex is as follows: breeding starts in Feb., recruitment of young takes place from April till June, and these start to mature in Nov./Dec. It is not certain if some animals which breed in the spring/early summer survive to breed the following year.
5. The life-cycle of C. crystallinus appears to be as follows: first instars present from May to Oct., second instars from May to Dec., third instars from June till following Jan., fourth instars all the year round, pupae from May till Aug., and eggs from May to Sept. Adult emergence takes place from late April till mid-Sept.
6. A six-week drought in Oct/beginning Nov. in the second year of the investigation caused considerable mortality in most species, but most survived with only a few exceptions.

     

Biogenesis of mitochondria 20 the effects of altered membrane lipid composition on mitochondrial oxidative phosphorylation inSaccharomyces cerevisiae

1. The lipid composition of mitochondria isolated from a fatty acid desaturase mutant ofSaccharomyces cerevisiae may be extensively manipulated by growing the organism on defined supplements of unsaturated fatty acid (UFA).
2. The fatty acid composition of the mitochondrial lipids closely follows that of the whole cells from which the mitochondria are isolated. UFA-depleted mitochondria contain normal levels of sterols, neutral lipids and total phospholipids, but have much lower levels of phosphatidyl inositides.
3. UFA-depleted mitochondria possess a full complement of cytochromes, oxidase both NAD-linked and flavoprotein-linked substrates at normal rates, and have levels of succinate and malate dehydrogenases similar to those of UFA-supplemented mitochondria. However, UFA-depletion has a marked effect on the ability of cytochromec to reactivate the NADH oxidase activity of cytochromec-depleted mitochondria.
4. The efficiency of oxidative phosphorylation decreases progressively with the UFA content of the mitochondria, and oxidative phosphorylation is completely lost in mitochondria containing approximately 20% UFA.
5. The incorporation of UFA into the lipids of UFA-depleted mitochondriain vivo results in a recoupling of oxidative phosphorylation. Recoupling is insensitive to both chloramphenicol and cycloheximide, indicating that all the proteins necessary for oxidative phosphorylation are present in UFA-depleted mitochondria, and that the less of oxidative phosphorylation is a purely lipid lesion.
6. ATPase activity is apparently unaffected by UFA-depletion, but³²P_i-ATP exchange activity is lost in mitochondria which have been extensively depleted in UFA.
7. Valinomycin stimulates the respiration of UFA-supplemented mitochondria in media containing potassium, but has no effect on the respiration of UFA-depleted mitochondria, suggesting that active transport of potassium is lost as a result of UFA-depletion.

     

Genetic Diversity Among Candida albicans Isolates Associated with Vertical Transmission in Preterm Triplets

We report a case of congenital candidiasis in triplets, in the context of premature labor at 25 weeks gestation, without symptomatic vaginitis or chorioamnionitis. All three infants died as a result of prematurity, aggravated by systemic candidiasis. Multi-locus sequence typing confirmed vertical transmission of Candida albicans from the mother to the triplets and revealed a slight diversity among the strains isolated from the neonates.     

Rigorous and extended application of information theory to the afferent visual system of the cat

1. Intracellular recording were obtained from P-cells of the LGN of the cat. The impulse trains of a single presynaptic retinal ganglion cell and the postsynaptic P-cell were separated by band-pass-filtering and subsequent amplitude discrimination.
2. The rates of information and transinformation for the visual channel from the eye to a ganglion cell and to the connected P-cell were calculated. Input signals to the channel were trains of light flashes of different rate, luminance and spatial distribution.
3. Transinformation was calculated without restrictive assumptions for the code.
4. The transient behaviour of the system in response to a flash was fully considered for information calculations. Additionally, it was ensured that the state of the (adaptive) channel was considered correctly.
5. Information theory was applied in an extended way. The time courses of information transfer were calculated for various flash stimuli and compared with each other.

     

Response of the population size and community structure of Paenibacillus spp. to different fertilization regimes in a long-term experiment of red soil

Background and aims

Paenibacillus spp. are widely considered to impact the fertility and health of soil. The aim of this study was to evaluate how different fertilization regimes affect the population size and community structure of Paenibacillus spp. over a long period of time in red soil.

Methods

Soil samples were collected from a long-term experiment and were then analyzed using real-time PCR and PCR-DGGE. The correlation analysis, PCA and RDA were used to explore the relationships among Paenibacillus spp. population, community structure and soil properties in different treatments.

Results

The pH was seriously decreased only by the application of chemical fertilizer. The largest population of Paenibacillus spp. was found in the soil treated with organic fertilizer application, while the richest diversity was observed in the soil treated only with the chemical fertilizer. The Paenibacillus spp., Paenibacillus alkaliterrae, Paenibacillus campinasensis, and Paenibacillus xylanilyticus were found in all treatments. Paenibacillus castaneae was found in the soil treated with NPK, and Paenibacillus pabuli was specifically observed in the lime-amended treatment. Paenibacillus taichungensis and Paenibacillus prosopidis were detected in the soil treated with only chemical fertilizer. Except for the ammonium and pH, all the tested soil fertility parameters (total C, total N, nitrate, available K and available P) could significantly affect both the Paenibacillus spp. population number and diversity. The soil pH was significantly correlated with Paenibacillus spp. diversity only.

Conclusions

Our results indicate that the different long-term fertilization regimes have varied impact on both the Paenibacillus spp. population size and the diversity of the community associated with the soil properties tested. These results can help to enrich the information on the response of beneficial soil microbes to different long-term fertilization regimes.     

Habitability of the early earth: Clues from the physiology of nitrogen fixation and photosynthesis

In the absence of direct evidence concerning the nature of the early Earth environments, it is acceptable under the uniformitarian principle to attempt to define primitive habitats from modern procaryotic physiology. Combining the rock and fossil record with present phylogenetic reconstuctions, application of this paleoecological approach to the evolutionary biochemistry and physiology of nitrogen fixation and photosynthesis leads to several inferences about the nature of Archean environments:

1. To stimulate nitrogenase evolution and avoid its repression, the activity of the NH ₄ ⁺ ion was less than 10^?3, and probably lower.
2. To be consistent with a moderately protective ozone screen, while not also repressing nitrogenase activity, incursions of abiotic dissolved oxygen at levels in the range 10^?1.2?10^?3.5 PAL would have been acceptable.
3. To induce the formation and activity of RuBP carboxylase, the pCO₂ was less than 100 PAL.
4. To support Photosystem I activity, sulfide concentrations of at least 10^?4 M were present in the photic zone.
5. To avoid a too-rapid oxidation of sulfide, the pH was probably between 6–7, where H₂S exceeds HS^?.

Evolutionary ‘pressure’ to stimulate the later development of oxygenic photosynthesis (Photosystem II), would require several subsequent habitat modifications:

1. Lowering the sulfide to < 10^?4 M to inhibit Photosystem I.
2. Raising the pH above neutral (HS^? > H₂S), to mediate more rapid oxidation of HS^?.
3. Maintaining either an illumination below 300–400 lux (to avoid photosynthetic O₂ self-repression of nitrogen fixation), or an adequate local source of combined nitrogen (aNH ₄ ⁺ > 10^?4) to repress nitrogen fixation entirely.

     

Antimicrobial activity and carbohydrate specificity of new mycelial lectins from Fusarium sp.

In the present study, ten Fusarium sp. were screened for the presence of lectins by hemagglutination assay using human and animal erythrocytes. Amongst them nine species, namely F. acuminatum, F. chlamydosporium, F. coeruleum, F. compactum, F. concolor, F. crookwellense, F. culmorum, F. decemcellulare and F. dimerum were found to possess lectin activity. Neuraminidase treatment to rabbit erythrocytes considerably augmented hemagglutination titre, but no such effect was observed with protease-treated erythrocytes. Lectins were tested for inhibition of hemagglutination activity against a panel of carbohydrates. Majority of the lectins were inhibited by L-fucose, D-galactose, bovine submaxillary mucin and dextran. γ-Globulin was inhibitory against lectins from F. acuminatum, F. chlamydosporium, F. compactum and F. culmorum at a concentration of >250 μg/mL, whereas bovine submaxillary mucin and porcine stomach mucin were observed to be strongest inhibitors of lectin from F. compactum with minimum inhibitory concentration of 7.18 μg/mL and 15.6 μg/mL, respectively. Most of the lectins displayed antimicrobial activity against Bacillus cereus, Escherichia coli, Staphylococcus aureus and Aspergillus niger. Lectins from F. chlamydosporium, F. culmorum and F. crookwellense have also exhibited antimicrobial activity against Candida albicans. These findings illustrate the significance of Fusarium sp. lectins in clinical applications.     

A study on the mechanism of energy coupling in the redox chain

The present study demonstrates that the mitochondrial respiratory chain includes not three but four energy coupling sites, the fourth site being localized at the NADPH→NAD⁺ step.

1. The NADPH→NAD⁺-directed transhydrogenase reaction in sonicated beef heart submitochondrial particles energizes the particle membrane as judged by two membrane potential probes, i.e. uptake of a penetrating anion, phenyldicarbaundecaborane (PCB^?), and enhancement of anilinonaphthalene sulfonate (ANS^?) fluorescence.
2. The reverse reaction (NADH→NADP⁺) is accompanied by the oppositely directed anion movement, i.e. PCB^? efflux.
3. Being insensitive to rotenone, antimycin, cyanide, and oligomycin, both the influx and efflux of PCB^? coupled with transhydrogenase reaction can be prevented or reversed by uncouplers.
4. Equalization of concentrations of the transhydrogenase substrates and products also prevents (or reverses) the PCB^? influx coupled with oxidation of NADPH by NAD⁺, as well as the PCB^? efflux coupled with reduction of NADP⁺ by NADH.
5. The transhydrogenase-linked PCB^? uptake depends linearly on the energy yield of the oxidation reaction calculated according to formula $$\Delta G = RTln\frac{{[NADPH] x [NAD^ + ]}}{{[NADP^ + ] x [NADH]^ \cdot }}$$ No threshold value of Δ was found. Measurable PCB^? transport was still observed at Δ≤0.5 kcal/mole NADPH oxidized.
6. Partial uncoupling of transhydrogenase reaction and PCB^? transport, induced by low concentrations ofp-trifluoromethoxycarbonylcyanide phenylhydrazone (FCCP), dinitrophenol, or by removing coupling factor F₁, results in the decrease of the slope of the straight line showing the PCB^? uptake as a function of Δ. Oligomycin improves the coupling in F₁-deprived particles, the slope being increased. Rutamycin, dicyclohexylcarbodiimide (DCCD) and reconstitution of particles with F₁, also increase the coupling.
7. In phosphorylating particles oxidizing succinate by O₂, both the energy-dependent NADH→NADP⁺ hydrogen transfer and PCB^? influx possess equal sensitivity to FCCP, which is lower than the sensitivity of oxidative phosphorylation. Similarly, the decrease in the succinate oxidation rate induced by malonate arrests first phosphorylation and then under higher malonate concentration, PCB^? influx. The rate of NADPH→NAD⁺ transhydrogenase reaction was found to be lower than the threshold value of rate of succinate oxidation, still coupled with phosphorylation. Respectively, the values of PCB^? uptake under transhydrogenase reaction are lower than those inherent in phosphorylating oxidation of succinate.

The conclusion is made that the NADPH→NAD⁺-directed transhydrogenase reaction generates the membrane potential of the same polarity as respiration and ATP hydrolysis but of a lower magnitude (“plus” inside particles; the forward hydrogen transfer). The NADH→NADP⁺-directed transhydrogenase reaction forms the membrane potential of the opposite polarity (“minus” inside particles; the reverse hydrogen transfer). Under conditions used, the transhydrogenase-produced membrane potential proves to be too low to support ATP synthesis (and, most probably, the synthesis of any other high-energy compound) maintaining, nevertheless, some electrophoretic ion fluxes. A conclusion is made that transhydrogenase forms a membrane potential with no high-energy intermediates involved.