Microbial oxidation of manganese in hydro-electric pipelines

Evidence is presented that stalked, budding bacteria (hyphomicrobia) are responsible for the deposition of manganese in certain freshwater pipelines in Tasmania. Laboratory-scale equipment is described which allows manganese oxidation to be studied under controlled conditions. In some pipelines the lack of deposition is due to insufficient manganese in the lake water and not to absence of the appropriate hyphomicrobia. The composition of the pipeline deposits in Tasmania and other parts of the world are strikingly similar, and it is suggested that hyphomicrobia occur in manganese deposits more frequently than has been recorded.     

Pleomorphy in Stalked, Budding Bacteria

An investigation of hyphomicrobia from manganese deposits and various fresh-water habitats revealed an astonishing degree of pleomorphy in the group. A range of variation spanning two described genera (Hyphomicrobium and Pedomicrobium) was induced by varying culture conditions and was further observed in natural environments. It is suggested that Pedomicrobium is an invalid genus.     

Lateral connections between heart muscle cells as revealed by conventional and high voltage transmission electron microscopy

Summary The lateral surfaces of heart muscle cells are interconnected by a varied and extensive network of structures that exist in addition to intercalated discs. Ultrastructural images of this network are vastly improved over those from epoxy-embedded material, particularly for low density components, through the application of a method for removing the embedding matrix from thin or thick sections that are then stereoscopically analyzed with standard or high voltage transmission electron microscopy. The connections include cables, 3–20 nm in diameter, multi-strand cables, 10–40 nm-granules, meshlike mats, and sheets, all extensively interwoven. It is suggested that intercellular connections of varying strength and distribution aid in the integration of mechanical performance of the large population of myocytes during the contractile cycle of the heart.This study was supported by a grant from NIH Biotechnology Resources through the University of Colorado High Voltage E.M. Laboratory, NIH Research Grant HL 24336, a N.Y. Heart Association Grant-in-Aid, and NIH Research Career Development Award HL 00568I thank Dr. E.H. Sonnenblick for continual aid and encouragement and Dr. R. Terry, Ms. Y. Kress, and Ms. J. Fant for use of facilities. I also thank Dr. K.R. Porter for guidance in the use of the HVEM technique, Dr. J.J. Wolosewick and Dr. M. Fotino for valuable suggestions, and Ms. J. Fleming, Mr. G. Wray, and Mr. G. Charlie of HVEM staff at Boulder. I acknowledge Dr. F. Pepe for use of facilities, Dr. R. Bloodgood for comments, and Mrs. L. Cohen-Gould, Ms. T. Downey, Mr. F. Reingold, Mrs. T. Maio, and Mrs. R. Shamoon for excellent assistance     

Some properties ofAchromatium oxaliferum

Studies on cells harvested from the natural habitat showed thatA. oxaliferum is gram-negative and catalase-negative. Electron micrographs of carefully fixed cells revealed the presence of peritrichously arranged appendages with a minimum thickness of 90 Å as well as capsular slime. The hypothesis is advanced that the gliding motility ofAchromatium is caused by peritrichous bacterial flagella beating in a slime layer that surrounds the cell.The skillful help of Mrs. W. M. Batenburg, Miss J. van Hooidonk, Mr. B. Oosterman and Mr. H. W. G. Meesters is gratefully acknowledged.     

The role of catastrophic death of Calluna in heathland dynamics

In the Breckland heaths of East Anglia large patches of Calluna are often killed by adverse climatic conditions or insect attack. This paper studies one site, Cavenham Heath, where large areas of Calluna were killed between 1976–1979, and shows that older stands were most affected, and recovery was slowest compared to either younger stands, or stands with an uneven-aged structure. Moreover, where Calluna death was most severe, directional succession to birch woodland was accelerated. At this site, although Calluna regeneration has been previously assumed to be initiated by endogenous factors (i.e. by the life cycle of the Calluna), it is also clearly interrupted by exogenous factors. The implications of these results for heathland conservation are discussed, and it is suggested that intervention management by cutting and burning, to maintain large areas of Calluna in the building phase, may be the most appropriate long term strategy.This work was funded in part by the Nature Conservancy Council as part of its research programme into nature conservation. I thank Mr D. Malins and Mrs D. Reynolds for assistance in both the field and the laboratory, Ms S. Ide and Mr J. Pattin-gale for preparing the figures, and Professor C. H. Gimigham, Dr J. Miles and Dr I. C. Prentice for helpful comments on earlier drafts of this paper.     

Observations on the gastric epithelium of ascidians with special reference to Styela clava

Summary Transmission electron microscopy shows the gastric epithelium of Styela clava to comprise at least three distinct cell types. Ciliated mucous cells which form the crest of each stomach ridge produce mucus by an unexpected route. Vacuolated cells lining the ridge sides appear to be absorptive in function. Gastric enzymes are produced by typical protein secreting cells scattered amongst the vacuolated cells. Undifferentiated cells are found in the crypts between ridges. The structure and function of the gastric epithelium in Styela is discussed with special reference to the wider concepts of ascidian gut organization.The author is grateful to Mrs. L. Rolph for technical help with scanning electron microscopy and Mr. J. Calvert and Mr. R. Jones for assistance with the transmission electron microscopy. Animals were collected through the kind offices of Mr. J. Sturges and other staff of the Admiralty Marine Trials Station, Portsmouth. This research was carried out during the tenure of SRC grant No. B/RG 82919 -The localization of polypeptide hormones in the pharynx and gut of Protochordates     

Some aspects of the fine structure of the statocysts of the molluscsPecten andPterotrachea

Summary The statocyst ofPecten is composed of hair cells and supporting cells. The hair cells bear kinocilia and microvilli at their distal ends and the supporting cells bear microvilli. The cilia have a 9+2 internal filament content, and arise from basal bodies that have roots, basal feet and microtubular connections. Two different ciliary arrangements are described, one with a small number of cilia arranged in a ring, and another with many more cilia arranged in rows. Below the hair cells are probable synapses. A ciliated duct connects to the lumen of the static sac and passes through the centre of the static nerve. The hair cells in the statocyst ofPterotrachea bear kinocilia and microvilli. The possible importance of cilia and microvilli in the transduction process is discussed.We would like to thank ProfessorJ. Z. Young for bringing specimens ofPterotrachea from Naples and also the staff of the Stazione Zoologica for the provision of specimens, Dr.M. Land for providing specimens ofPecten, the Science Research Council (U.K.) for providing the electron microscope used in much of the study and also for a grant to one of us (V.C.B.), and Mrs.J. Parkers and Mr.R. Moss and Mrs.J. Hamilton for much photographic and technical assistance.     

Cytologic and metabolic parameters of pineal inhibition by continuous light in the rat (Rattus norvegicus)

Summary Adult rats (Rattus norvegicus) were subjected to continuous light or control conditions (14 hours light/day) for six weeks or longer, and quantitative cytological and metabolic studies were made of the pineal organs. After 11 weeks of continuous light, the pineal parenchymal cell's largest nucleolar eosinophilic mass is significantly reduced in diameter, especially in the medulla of the organ. Evidence of metabolic inhibition includes reduction of pineal glycogen content, succinic dehydrogenase activity, and respiration in the absence of exogenous substrates. Pineal ATP content, P³²-phosphate uptake and 5-hydroxy indole acetic acid content did not appear to be affected. Pineal serotonin content and melatonin-forming activity in the continuously lighted animals were measured but could not be interpreted metabolically, due to the diurnal fluctuations of these in control animals. Results provided here and elsewhere suggest that pineal inhibition by continuous light involves primarily the citric acid cycle, the accumulation of metabolites and lipid, and the synthesis of protein.This investigation was supported by grant GM-05219 from the National Institutes of Health, U.S. Public Health Service.I am grateful to Mrs. Virginia Green Bowers, Mrs. Ann Richards, Mr. Peter Charles Baker and Mr. Jorge Antonio Alvarado for laboratory assistance, and to Dr. Richard Strohman and Mr. David Epel, for advice on the determination of ATP.     

The morphology of the juxtaglomerular apparatus in the toad,Bufo bufo

Summary In a light microscopic study the course of the tubule in the kidney of the toadBufo bufo was studied. The distal tubule returning to the glomerulus of its origin appears to enclose the afferent arteriole. In that area, from which a three dimensional graphic reconstruction is made, there is an intimate contact between tubular and vascular wall. The latter contains granulated media cells. In the part of the tubule adjacent to the afferent arteriole an accumulation of nuclei is present. It is suggested that this structure is similar to the macula densa of the mammalian juxtaglomerular apparatus. The functional significance of a stricture in the tubule distally from the macula densa-like structure is discussed.The authors wish to thank Mrs. Ineke van de Mee-Wienen and Miss Ans Rouwenhorst for their technical assistance and Mr. J. J. M. de Bekker for the realization of the graphic reconstruction.     

Age changes in the centrally and peripherally located sensory neurons in rat

Summary Lipofuscin pigment formation and distribution in the Mes. N.5 neurons, trigeminal and spinal ganglia of male Wistar rats of 2, 14, 32 and 49 months as an indication of aging has been investigated. These intraneuronal pigment granules are found as early as 2 months in all the cells, and continue to accumulate in all the cells in varying amounts until the first year of life. The different rate at which lipofuscin accumulates probably shows the difference in the maturation of the functionally related cells. At later stages the obvious findings are complex pigment body formation and localization of the pigment bodies either at one pole as seen in the Mes. N. 5 neurons or arranged submembranously parallel to the long axis of the cells in the ganglia. The vacuolated lipofuscin pigment bodies are bound by a double limiting membrane and among the vacuoles are found tubular membranous structures resembling residual mitochondrial substructures. These findings suggest a mitochondrial origin of lipofuscin, rather than a lysosomal. The intracellular pigment bodies seen in the perineuronal satellite cells of peripheral ganglia appear to be signs of removal of lipofuscin from the ganglion cells. Acknowledgements. We wish to thank Mr. J. Kirchhoff, Miss E. Heyder, Mr. W. Dresp and Mrs. M. del C. Weinrichter for the technical assistance, Mr. R. Dungan and Mrs. S. Ruelke for the photographic work. We are grateful to the DAAD and the Universitätsbund of the University of Göttingen for the financial assistance. This work was supported by the Deutsche Forschungsgemeinschaft, Grant No. G1 28, 16/17.DAAD fellow on leave from the Department of Anatomy, A.I.I.M.S., New Delhi 16, India.     

Observations on the fine structure of a methane-oxidizing bacterium

Structural details of membranes, intracellular organelles, and the cell wall of a methane-utilizing bacterium identified as aMethylomonas sp. were studied by electron microscopy. The cell wall structure is similar to that found in other gram-negative bacteria. The cytoplasmic membrane shows invaginations, presumably forming the internal membrane bundles. Two types of polar organelles were encountered. In older cells myelin-like structures were observed. Under certain cultural conditions bleb-formation and possibly accumulation of reserve materials occurred. We wish to thank Mrs. M. H. Bakker-van der Velden, Mrs. W. H. Batenburgvan der Vegte and Miss J. C. de Bruyn for making the electron microscopical preparations and photographs. Thanks are due to Mr R. S. M. Revell of the Philips E. M. Application Laboratory, Eindhoven, for the photographs with the goniometer attachment.     

Distribution of monoamine oxidase in the hippocampal region of the guinea pig

Summary 1. The distribution of monoamine oxidase (MAO) within the dentate area, a part of the hippocampal region, has been described for the adult guinea pig.2. The histochemical demonstration of the enzyme was done essentially according to the tryptamine-tetrazolium method of Glenner et al., and the staining reactivity was controlled by complete inhibition with iproniazide.3. Most of the MAO in the dentate area was present in a stratified pattern. Within the molecular layer, a supragranular third reacted heavily, while a more weakly staining superficial layer could be distinguished from an intermediate, still paler lamina. The granular cell bodies were unstained. In the hilus, five layers showing alternating stronger and weaker activity were observed. The distribution of the MAO staining was compared with conventional anatomical subdivision of the dentate region.4. The guinea pig dentate area appears to have a greater amount and more stratified distribution of MAO than the comparable region previously described in the rat.I am indebted to Mrs. E. Kjær Hansen, Mrs. L. Knudsen, Mr. A. Meier, Mr. Th. Nielsen, Mrs. K. Sørensen, and Miss M. Sørensen for skillful technical assistance. This study was supported in part by U.S.P.H.S. Grant NS 07998.     

Isolation and identification of orsellinic acid and penicillic acid produced byPenicillium fennelliae Stolk

Fifteen days-old surface cultures ofPenicillium fennelliae Stolk grown on a modified Czapek medium were analyzed for the production of metabolites. The presence of orsellinic acid, orcinol and penicillic acid was proved by means of chromatographic and physicochemical methods.The author is indebted to Mr. J. A. Weber and Dr. M. J. A. de Bie of the Laboratory of Organic Chemistry, University of Utrecht for measuring the UV and 60 Mc NMR spectra and to Mrs. G.E.E. Snijders-Woldringh, Miss L. Veldstra and Miss H. G. M. Stolwijk of the Institute for Organic Chemistry TNO, Utrecht for running the IR and 100 Mc NMR spectra and for performing the microanalysis.The mass spectra were determined by Mr. W. Heerma of the Analytical Laboratory, University of Utrecht, whom we wish to thank for helpful discussions on the interpretation of the results.The skillful technical assistance of Miss M. van Rietschote is gratefully acknowledged.     

Vinblastine-induced paracrystals and unusually large microtubules (macrotubules) in rat renal cells

Summary Vinblastine sulfate was administered to adult rats by intravenous injections. Kidney cortex was fixed after 1, 2, or 5 hours of treatment and studied by routine transmission electron microscopy.In control animals, cells of distal convoluted tubules possessed numerous microtubules with an average diameter of 280 Å. In treated animals, the microtubules of these cells were reduced in number, and paracrystalline inclusions characteristic of vinblastine treatment were common. Macrotubules (570 Å average diameter) were also present and often were seen close to, or in apparent continuity with, paracrystals. Since the work of others indicates that vinblastine-induced paracrystals contain microtubular protein (tubulin), observation of continuities between paracrystals and macrotubules is interpreted as evidence that macrotubules are also composed of tubulin and that macrotubules may become incorporated into paracrystals.Unlike the ordinary microtubules of cells of the distal tubules, vinblastine-induced macrotubules exhibited cross-striations in longitudinal view and subunit structure in cross section.Macrotubules and paracrystals were also observed in cells of the proximal convoluted tubule, mesangium, glomerular endothelium, parietal epithelium of Bowman's capsule, and visceral epithelium of Bowman's capsule. Continuities between macrotubules and paracrystals, although relatively common in occurrence in distal tubule cells, were only rarely seen in the other kinds of cells examined. Acknowledgements. The authors gratefully acknowledge the technical help of Mrs. Dawn Bockus, Miss Judy Groombridge, Mrs. Jeri Hunter, Mrs. Jolan Pinter, Miss Franque Remington, Miss Mary Stewart, Miss Louise Young, Mr. Reginald Pickering, and Mr. W. J. Masten. This research was supported by N.I.H. grants AM 16 236, GM 00 100, and HE 03 174, by Institutional Cancer Grant IN-26L from the American Cancer Society, and by the Graduate School Research Fund of the University of Washington.     

Microbial Communities Inhabiting a Rare Earth Element Enriched Birnessite-Type Manganese Deposit in the Ytterby Mine,Sweden

The dominant initial phase formed during microbially mediated manganese oxidation is a poorly crystalline birnessite-type phyllomanganate. The occurrence of manganese deposits containing this mineral is of interest for increased understanding of microbial involvement in the manganese cycle. A culture independent molecular approach is used as a first step to investigate the role of microorganisms in forming rare earth element enriched birnessite-type manganese oxides, associated with water bearing rock fractures in a tunnel of the Ytterby mine, Sweden. 16S rRNA gene results show that the chemotrophic bacterial communities are diverse and include a high percentage of uncultured unclassified bacteria while archaeal diversity is low with Thaumarchaeota almost exclusively dominating the population. Ytterby clones are frequently most similar to clones isolated from subsurface environments, low temperature milieus and/or settings rich in metals. Overall, bacteria are dominant compared to archaea. Both bacterial and archaeal abundances are up to four orders of magnitude higher in manganese samples than in fracture water. Potential players in the manganese cycling are mainly found within the ferromanganese genera Hyphomicrobium and Pedomicrobium, and a group of Bacteroidetes sequences that cluster within an uncultured novel genus most closely related to the Terrimonas. This study strongly suggest that the production of the YBS deposit is microbially mediated.     

The structure of the nerve fibre layer and neurocord in the enteropneusts

Summary The nerve fibre layer and the neurocord of the Enteropneusts Saccoglossus horsti, Harrimania kupfferi and Ptychodera flava have been examined with the electron microscope. The nerve fibres vary in diameter between 0.15 to 10 m. The majority of the fibres are of the smaller diameters. The nerve fibre layer is intraepidermal, and is divided by processes running radially from the epithelial cells to the basement membrane that separates the nerve fibre layer from the muscle cells.The cells of origin of these nerve fibres are situated mainly in the innermost layers of the epidermal cells. The nerve fibre profiles contain numerous vesicles of very varied diameter and contents, together with larger granular inclusions that are also found in the nerve cell bodies.Morphologically recognisable synapses are rare, but the majority of fibres are in intimate contact with one another. Sometimes the mass of fibres is divided into bundles by the epithelial cell processes. The majority of giant fibres are situated near to the basement membrane of the neurocord. The giant fibres also have a varied content of vesicles as well as neurofilaments and neurotubules.The central canal in Ptychodera flava and the remnants of the central canal in Saccoglossus horsti are both lined by columnar cells that bear microvilli as well as cilia with the typical 9 + 2 pattern of tubules. Scattered amongst these cells are mucus secreting cells which open into the cavity of the canal.I (P.N.D.) should like to thank Professor J. Z. Young, F. B. S. for much advice and encouragement. Dr. R. Bellairs generously provided the electron microscope facilities, and Dr. R. Newell kindly collected and identified the Saccoglossus specimens. Mr. R. Moss, Mrs. J. Hamilton and Mr. A. Aldrich gave excellent technical and photographic assistance.     

Leptodon Smith (Hedw.) Mohr in Ireland

Abstract

A new Irish locality is recorded for L. smithii, and the general features of the station are described. An account of the bryophyte succession on tree trunks in the area is given and the part played by L. smithii indicated. It is shown that gatherings from both Irish localities consisted entirely of male plants and the distribution and age of the antheridia on both specimens are recorded. It is suggested that rarity of sporophyte production in the British Isles is probably due to too great a spatial separation of male and female plants and not to the absence, or low production, of sex organs. It is also suggested that rarity of spores and impermanence of the habitat are the chief factors contributing to its rareness in climatically suitable areas of the British Isles. The known distribution of the plant in the British Isles is related to its European and world distribution, and it is shown that L. smithii may be expected in further Irish vice counties.

I have pleasure in acknowledging my thanks to Mr Wallace for the gift of a specimen of L. smithii from Knocklofty and for details of its habitat; to Mrs C. E. M. Shelswell-White for permission to enter and collect in the grounds of Bantry House, and to my colleague Dr J. G. Hawkes for confirming the identification of the two shrubs.     

Electron microscope studies on collagen

Summary The present paper describes the effect of intensive tryptic digestion of native tropocollagen (TC) macromolecules in solution. Contrary to earlier investigations it has been found that the trypsin treatment results in a fragmentation of the TC molecules. The addition of ATP to solutions exposed to the enzyme yields SLS fragments, 2250 Å in length. Comparison between these and normal SLS type aggregates shows that the scission occurs in a well-defined locus adjacent to the -1/2-line seen after positive staining. The significance of this finding is discussed.This study was supported by grant NB-02215-04 from the National Institute of Neurological Diseases and Blindness, Public Health Service, U.S.A. and a Student research fellowship from the Norwegian Research Council for Science and the Humanities. This aid is gratefully acknowledged.I am indebted to Mrs. J. Line Vaaland and Mr. B. V. Johansen for technical assistance.     

Studies on the receptors in Ciona intestinalis

Summary A photoreceptor type structure not previously described has been found in the dorsal wall of the cerebral vesicle of the tadpole larva of Ciona intestinalis. The membranes of this receptor are organised as tubules some 60–100 nm in diameter and up to 1.5 m long. The tubules are confined in bundles about 1.5 m in diameter, which extend from the cell surface into the cavity of the cerebral vesicle. These tubules are similar to those in the rhabdomeric type of photoreceptor. However, in the cells from which the tubule processes arise are structures typical of the bases of cilia, and found in ciliary type photoreceptors.I should like to thank Professor J. Z. Young, F. R. S. for his continuing encouragement and help, and Dr. R. Bellairs for the use of electron microscope facilities. Mr. R. Moss and Mrs. J. Hamilton gave excellent technical assistance.