DOCSLIB.ORG

3. Aerobic Gammaproteobacterial Methanotrophs Mitigate Methane Emissions from Oxic and Anoxic Lake Waters

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
3. Aerobic Gammaproteobacterial Methanotrophs Mitigate Methane Emissions from Oxic and Anoxic Lake Waters Research Collection Doctoral Thesis Methane oxidation in suboxic and anoxic zones of freshwater lakes Author(s): Oswald, Kirsten Publication Date: 2016 Permanent Link: https://doi.org/10.3929/ethz-a-010708140 Rights / License: In Copyright - Non-Commercial Use Permitted This page was generated automatically upon download from the ETH Zurich Research Collection. For more information please consult the Terms of use. ETH Library DISS. ETH NO. 23298 METHANE OXIDATION IN SUBOXIC AND ANOXIC ZONES OF FRESHWATER LAKES A thesis submitted to attain the degree of DOCTOR OF SCIENCES of ETH ZURICH (Dr. sc. ETH Zurich) presented by KIRSTEN OSWALD M.Sc. Applied Environmental Geoscience, Eberhard Karls Universität Tübingen born on 09.03.1983 citizen of Germany accepted on the recommendation of Prof. Dr. Bernhard Wehrli, examiner Dr. Carsten J. Schubert, co-examiner Prof. Dr. Marcel M. M. Kuypers, co-examiner Prof. Dr. Martin Ackermann, co-examiner 2016 TABLE OF CONTENTS ACKNOWLEDGEMEMTS .................................................................................................................... 3 SUMMARY ............................................................................................................................................ 5 ZUSAMMENFASSUNG ........................................................................................................................ 7 1. INTRODUCTION ........................................................................................................................... 9 1.1. Methanogenesis ..................................................................................................................... 10 1.2. Methane oxidation ................................................................................................................. 11 1.3. Methane production and emission from lakes ....................................................................... 16 1.4. Methane oxidation dynamics in lakes ................................................................................... 17 1.5. Study sites ............................................................................................................................. 19 1.6. Overview of methods ............................................................................................................ 21 1.7. Objectives and outline ........................................................................................................... 24 1.8. Contribution to related publications ...................................................................................... 25 2. LIGHT-DEPENDENT AEROBIC METHANE OXIDATION REDUCES METHANE EMISSIONS FROM SEASONALLY STRATIFIED LAKES ............................................................. 27 2.1. Abstract ................................................................................................................................. 28 2.2. Introduction ........................................................................................................................... 28 2.3. Materials and Methods .......................................................................................................... 30 2.4. Results ................................................................................................................................... 37 2.5. Discussion ............................................................................................................................. 42 2.6. Acknowledgments ................................................................................................................. 49 2.7. Supporting Information ......................................................................................................... 49 3. AEROBIC GAMMAPROTEOBACTERIAL METHANOTROPHS MITIGATE METHANE EMISSIONS FROM OXIC AND ANOXIC LAKE WATERS ............................................................ 53 3.1. Abstract ................................................................................................................................. 54 3.2. Introduction ........................................................................................................................... 54 3.3. Methods ................................................................................................................................. 56 3.4. Results ................................................................................................................................... 63 3.5. Discussion ............................................................................................................................. 71 3.6. Acknowledgements ............................................................................................................... 78 3.7. Supplementary Information ................................................................................................... 78 4. CRENOTHRIX POLYSPORA: AN IMPORTANT OVERLOOKED PLAYER IN FRESHWATER METHANE OXIDATION ........................................................................................ 83 4.1. Summary ............................................................................................................................... 84 4.2. Results and Discussion .......................................................................................................... 84 4.3. Methods ................................................................................................................................. 89 4.4. Acknowledgements ............................................................................................................... 90 I Table of Contents 4.5. Extended Data ....................................................................................................................... 91 4.6. Supplementary Information ................................................................................................... 92 5. METHANE OXIDATION IN THE FERRUGINOUS LAKE LA CRUZ (SPAIN) .................... 97 5.1. Abstract ................................................................................................................................. 98 5.2. Introduction ........................................................................................................................... 98 5.3. Methods ............................................................................................................................... 100 5.4. Results ................................................................................................................................. 106 5.5. Discussion ........................................................................................................................... 114 5.6. Acknowledgements ............................................................................................................. 121 5.7. Supplementary Information ................................................................................................. 122 6. CONCLUSIONS AND OUTLOOK ........................................................................................... 125 6.1. Methane, isotopes and oxidation dynamics ......................................................................... 125 6.2. Methanotrophic community ................................................................................................ 126 6.3. A novel methanotroph in lake water ................................................................................... 127 6.4. Photosynthesis fueled methanotrophy ................................................................................. 127 6.5. Methane oxidation and alternative electron acceptors ........................................................ 128 REFERENCES .................................................................................................................................... 131 II ACKNOWLEDGEMEMTS First and foremost, I would like to express my gratitude to my supervisors, Dr. Carsten Schubert and Prof. Bernhard Wehrli, for giving me the opportunity to complete my PhD studies in their groups. I really appreciate your guidance, trust, encouragement and advice. I am especially thankful for the freedom and resources I was able to benefit from. I would like to thank my co-examiner and collaborator, Prof. Marcel Kuypers, for his valuable input, expertise and for hosting me at the MPI for several scientific visits. I greatly appreciate the chance to have worked in partnership with another institute. I am grateful to Prof. Martin Ackermann for co-examining my thesis and for his helpful comments. A special thank you goes to Dr. Jana Milucka and Dr. Andreas Brand, who offered their support and proficiency in the lab and during field work. Thank you for countless discussions, ideas and motivation. I am immensely thankful to all technicians and staff at Eawag and the MPI for their continuous assistance and patience in the lab, in the field and with various analyses: Dr. Sten Littmann, Serge Robert, Daniela Tienken, Patrick Kathriner, Karin Beck, Alois Zwyssig, Daniela Nini, David Kistler, Irene Brunner, Gijs Nobbe, Francisco Vásquez, Gabriele Klockgether and Kirsten Imhoff. In particular, I would like to acknowledge Christian Dinkel for all his expert support during field campaigns. Thank you for making everything run smoothly on the boat, your fun company and positive disposition. Dr. Prosper Zigah, I am grateful for your help and skills, especially during the Lake Kivu campaign,
Load more

Recommended publications
  • Spontaneous Generation & Origin of Life Concepts from Antiquity to The
    SIMB News News magazine of the Society for Industrial Microbiology and Biotechnology April/May/June 2019 V.69 N.2 • www.simbhq.org Spontaneous Generation & Origin of Life Concepts from Antiquity to the Present :ŽƵƌŶĂůŽĨ/ŶĚƵƐƚƌŝĂůDŝĐƌŽďŝŽůŽŐLJΘŝŽƚĞĐŚŶŽůŽŐLJ Impact Factor 3.103 The Journal of Industrial Microbiology and Biotechnology is an international journal which publishes papers in metabolic engineering & synthetic biology; biocatalysis; fermentation & cell culture; natural products discovery & biosynthesis; bioenergy/biofuels/biochemicals; environmental microbiology; biotechnology methods; applied genomics & systems biotechnology; and food biotechnology & probiotics Editor-in-Chief Ramon Gonzalez, University of South Florida, Tampa FL, USA Editors Special Issue ^LJŶƚŚĞƚŝĐŝŽůŽŐLJ; July 2018 S. Bagley, Michigan Tech, Houghton, MI, USA R. H. Baltz, CognoGen Biotech. Consult., Sarasota, FL, USA Impact Factor 3.500 T. W. Jeffries, University of Wisconsin, Madison, WI, USA 3.000 T. D. Leathers, USDA ARS, Peoria, IL, USA 2.500 M. J. López López, University of Almeria, Almeria, Spain C. D. Maranas, Pennsylvania State Univ., Univ. Park, PA, USA 2.000 2.505 2.439 2.745 2.810 3.103 S. Park, UNIST, Ulsan, Korea 1.500 J. L. Revuelta, University of Salamanca, Salamanca, Spain 1.000 B. Shen, Scripps Research Institute, Jupiter, FL, USA 500 D. K. Solaiman, USDA ARS, Wyndmoor, PA, USA Y. Tang, University of California, Los Angeles, CA, USA E. J. Vandamme, Ghent University, Ghent, Belgium H. Zhao, University of Illinois, Urbana, IL, USA 10 Most Cited Articles Published in 2016 (Data from Web of Science: October 15, 2018) Senior Author(s) Title Citations L. Katz, R. Baltz Natural product discovery: past, present, and future 103 Genetic manipulation of secondary metabolite biosynthesis for improved production in Streptomyces and R.
    [Show full text]
  • Reader 19 05 19 V75 Timeline Pagination
    Plant Trivia TimeLine A Chronology of Plants and People The TimeLine presents world history from a botanical viewpoint. It includes brief stories of plant discovery and use that describe the roles of plants and plant science in human civilization. The Time- Line also provides you as an individual the opportunity to reflect on how the history of human interaction with the plant world has shaped and impacted your own life and heritage. Information included comes from secondary sources and compila- tions, which are cited. The author continues to chart events for the TimeLine and appreciates your critique of the many entries as well as suggestions for additions and improvements to the topics cov- ered. Send comments to planted[at]huntington.org 345 Million. This time marks the beginning of the Mississippian period. Together with the Pennsylvanian which followed (through to 225 million years BP), the two periods consti- BP tute the age of coal - often called the Carboniferous. 136 Million. With deposits from the Cretaceous period we see the first evidence of flower- 5-15 Billion+ 6 December. Carbon (the basis of organic life), oxygen, and other elements ing plants. (Bold, Alexopoulos, & Delevoryas, 1980) were created from hydrogen and helium in the fury of burning supernovae. Having arisen when the stars were formed, the elements of which life is built, and thus we ourselves, 49 Million. The Azolla Event (AE). Hypothetically, Earth experienced a melting of Arctic might be thought of as stardust. (Dauber & Muller, 1996) ice and consequent formation of a layered freshwater ocean which supported massive prolif- eration of the fern Azolla.
    [Show full text]
  • Robert Koch (1843-1910)
    [From Erastus: Varia Opuscula Medica. Francofurdi, 1590.] ANNALS OF MEDICAL HISTORY New Ser ie s , Volu me VII Mar ch , 1935 Numb er 2 ROBERT KOCH (1843-1910) AN AMERICAN TRIBUTE Par t I By LAWRASON BROWN, M.D. SARANAC LAKE, N. Y. IT seems fitting in In 1876 at the head of the Botanical our busy lives to Institute in Breslau was Ferdinand pause this year *Cohn, the greatest figure in bacteri- (1932) to do hom- ology before Koch, who had worked age to the memory out the first morphological classifica- of one of the im- tion of bacteria, putting bacteria in mortals of this the vegetable kingdom, and had found earth, Robert spores in Bacillus subtilus, for up to Koch, discoverer this time bacteria were still con- of the use of solid sidered a part of Botany. The work of media in bacteriology, discoverer of Schroeder on pigment bacteria, done the method of obtaining pure cultures under Cohn, is still a classic. of bacteria, discoverer of the methods On April 22, 1876, Cohn received a of sterilization against bacteria (thus letter from Wollstein in Posen. “Es- making modern [aseptic] surgery pos- teemed Herr Professor,” it began . sible), discoverer of tuberculin, dis- coverer among other bacteria of the Stimulated by your work on bacteria tubercle bacillus, just fifty years ago; published in Contributions to the Biology in fact the Father of scientific bacteri- of Plants, I have for some time been at work on investigations of anthrax con- ology. He takes his place with Pasteur and Lister among the great benefactors * Called “ Pflanzen-Cohn ” to separate him of mankind.
    [Show full text]
  • Robert Koch from Obscurity to Glory to Fiasco
    Robert Koch From Obscurity to Glory to Fiasco Martin Dworkin Professor Emeritus, MicroBiology University of Minnesota Article Number: 1 Date of publication: October 5, 2011 Follow this and additional works at: http://purl.umn.edu/148010 Recommended Citation: Dworkin, Martin (2013). Robert Koch From Obscurity to Glory to Fiasco, Journal of Opinions, Ideas, and Essays. October 5.2011 Article #1. Available at http://purl.umn.edu/148010. Submissions will be accepted from any member of the University of Minnesota community. Access will be free and open to all. ROBERT KOCH: FROM OBSCURITY TO GLORY TO FIASCO Martin Dworkin Department of Microbiology University of Minnesota The Early Years Nunquam otiosus (21) Robert Koch was born in 1843 in Clausthal, Germany, a small mining city in Lower Saxony. His father was a mining engineer and Robert was one of eleven surviving children. During his early education he decided to become a teacher but always had an inclination toward natural science. Shortly after entering the University of Gottingen, one of Germany’s leading universities, his interactions with such great scientists as Henle, Wohler, and Meissner convinced him that natural science was to be his destiny. However, practical considerations led him to study medicine. While it became quickly clear that he had a talent for experimentation, Koch was a practical man and his impending marriage to Emmy Fraatz made it clear that a steady source of income was a reality. After completing his medical studies in 1866, Koch took and passed the state medical examination and became licensed to practice medicine. During the next six years he had five different positions as a practicing physician.
    [Show full text]
  • History of Genetics Book Collection Catalogue
    History of Genetics Book Collection Catalogue Below is a list of the History of Genetics Book Collection held at the John Innes Centre, Norwich, UK. For all enquires please contact Mike Ambrose [email protected] +44(0)1603 450630 Collection List Symposium der Deutschen Gesellschaft fur Hygiene und Mikrobiologie Stuttgart Gustav Fischer 1978 A69516944 BOOK-HG HG œ.00 15/10/1996 5th international congress on tropical agriculture 28-31 July 1930 Brussels Imprimerie Industrielle et Finangiere 1930 A6645004483 œ.00 30/3/1994 7th International Chromosome Conference Oxford Oxford 1980 A32887511 BOOK-HG HG œ.00 20/2/1991 7th International Chromosome Conference Oxford Oxford 1980 A44688257 BOOK-HG HG œ.00 26/6/1992 17th international agricultural congress 1937 1937 A6646004482 œ.00 30/3/1994 19th century science a selection of original texts 155111165910402 œ14.95 13/2/2001 150 years of the State Nikitsky Botanical Garden bollection of scientific papers. vol.37 Moscow "Kolos" 1964 A41781244 BOOK-HG HG œ.00 15/10/1996 Haldane John Burdon Sanderson 1892-1964 A banned broadcast and other essays London Chatto and Windus 1946 A10697655 BOOK-HG HG œ.00 15/10/1996 Matsuura Hajime A bibliographical monograph on plant genetics (genic analysis) 1900-1929 Sapporo Hokkaido Imperial University 1933 A47059786 BOOK-HG HG œ.00 15/10/1996 Hoppe Alfred John A bibliography of the writings of Samuel Butler (author of "erewhon") and of writings about him with some letters from Samuel Butler to the Rev. F. G. Fleay, now first published London The Bookman's Journal
    [Show full text]
  • Miros£Aw Syniawa
    Biograficzny s³ownik przyrodników œl¹skich tom 1 MIROS£AW SYNIAWA Biograficzny s³ownik przyrodników œl¹skich tom 1 CENTRUM DZIEDZICTWA PRZYRODY GÓRNEGO ŒL¥SKA A Copyrigth © by Centrum Dziedzictwa Przyrody Górnego Śląska Wydawca: Centrum Dziedzictwa Przyrody Górnego Śląska Katowice 2006 Redaktor: Jerzy B. Parusel Okładka: Joanna Chwoła, Mirosław Syniawa Realizacja poligraficzna: Verso Nakład: 500 egzemplarzy ISBN 83906910−7−8 5 A WSTĘP Koncepcja tego słownika narodziła się wraz z początkiem współpracy jego autora z Centrum Dziedzictwa Przyrody Górnego Śląska i pierwszymi biografiami śląskich przyrodników, jakie pisał do kwartalnika „Przyroda Górnego Śląska”. Chcąc zmierzyć się z zadaniem kompilacji tego rodzaju słownika, autor miał dość mgliste wyobrażenie na temat rozmiarów czekającej go pracy i ilości materiałów, jakie trzeba będzie zgro− madzić i opracować. Świadomość ogromu pracy, jaka go czeka, wzrastała jednak, w miarę jak zbliżał się do końca pracy nad częścią pierwszą, która ostatecznie ukazała się w roku 2000 jako trzeci tom publikowanej przez Centrum serii „Materiały Opracowania”. Udało się w niej na 252 stronach zmieścić pierwszą setkę biogramów. Ponieważ zawierającej kolejne 100 biografii części drugiej, nad którą pracę autor ukończył w roku 2004, nie udało się wydać w ramach wspomnianej serii, należało poszukać innej drogi, by udostępnić czytelnikom opra− cowany materiał. Jednocześnie pojawiła się też potrzeba zarówno wznowienia pierwszej części, której niewielki nakład został w krótkim czasie wyczerpany, jak i skorygowania błędów, które się w niej pojawiły i wprowadzenia uzupełnień opartych na materiałach źródłowych, jakie udało się autorowi zgromadzić od czasu jej wydania. Opracowany materiał postanowił on ponadto uzupełnić biogramami, które nie weszły do obu ukończonych już części, i biogramami, które powstały po ukończeniu części drugiej.
    [Show full text]
  • Ferdinand Julius Cohn (1828-1898): Pioneer of Bacteriology
    Ferdinand Julius Cohn (1828-1898): Pioneer of Bacteriology King-Thom Chung, Department of Microbiology and Molecular Cell Sciences, The University of Memphis, Memphis, Tennessee 38152 http://www.mhhe.com/biosci/cellmicro/nester/graphics/nester3ehp/common/cohn.html Ferdinand Julius Cohn was not as famous as Louis Pasteur (1822-1895) and Robert Koch (1843-1910) because he worked on the classification of bacteria, thus he did not attract as much the attention of the general public as those who worked on the relationships of microorganisms with human diseases. His contributions include systematic classification of bacteria, discovery of bacterial spore, help in disproving the fallacy of spontaneous generation, and establishing a journal "Beitrage zur Biologie der Pflanzen" which served as an important vehicle for the publications of many pioneer bacteriological papers. Cohn’s work also helped establish the recognition of bacteria as a separate group of living organisms different from plants or animals. Ferdinand was born on January 24, 1828 in Breslau (now Wroclaw), Lower Silesia, now in Poland. His father, Issak Cohn, was poor and lived in Breslau’s Jewish ghetto when Ferdinand was born. But Issak became a successful merchant and he cared very much about the education for his children. To his great joy, Ferdinand was a genius, he could read at the age of two and was interested in natural history at very young age. He first attended the school at the age of four. In 1835, he entered the Breslau Gymnasium (equivalent to high school) and did very well in all courses. Unfortunately, at the age of ten or eleven, he developed for a unknown reason a hearing defect, which slowed his incredible pace of learning.
    [Show full text]
  • Early History of Microbiology and Microbiological Methods
    1 EARLY HISTORY OF MICROBIOLOGY AND MICROBIOLOGICAL METHODS Robert F. Guardino AAI Development Services Wilmington, N.C. USA INTRODUCTION The original title of this chapter was to be “History of Microbiological Methods.” This would seem to indicate that inquisitive minds were consciously attempting to develop new methods for a new field of science. Or perhaps they had a “for profit” motive as if they were working for a company driving them towards new markets or to increase their portfolio of patents from which to draw royalties. This could not be further from the truth. Rather, the history of microbiology is a story of some common folk and other rather peculiar individuals, janitors and hobbyists, amateur lens grinders and chemists, physicians and botanists, housewives and laboratory “slaves” with a quest for discovery. These explorers were sometimes driven by chance or curiosity, and sometimes by a problem for which no one had an answer. And, they were driven sometimes by pride or self-interest. But then there were those altruistic ones driven by the pure compassion for suffering humanity. With the topic being rather broad, and the space being somewhat limited, the scope had to be narrowed so this chapter has mutated into one that attempts to expose the minds behind the discoveries; 1 www.pda.org/bookstore 2 Encyclopedia of Rapid Microbiological Methods discoveries that necessitated the rather simple, though not always obvious, techniques that made revealing the world of microorganisms possible. The story that unfolds is first a history of events and phenomenon for which there was no understanding or explanation, followed by observations for which there was no obvious application, to the eventual association of cause and effect, on to a full blown field of inquiry.
    [Show full text]
  • History of the Membrane (Pump) Theory of the Living Cell from Its
    Physiol. Chem. Phys. & Med. NMR (2007) 39:1–67 History of the Membrane (Pump) Theory of the Living Cell from Its Beginning in Mid-19th Century to Its Disproof 45 Years Ago — though Still Taught Worldwide Today as Established Truth Gilbert Ling Damadian Foundation for Basic and Cancer Research Tim and Kim Ling Foundation for Basic and Cancer Research E-mail: [email protected] Abstract: The concept that the basic unit of all life, the cell, is a membrane-enclosed soup of (free) water, (free) K+ (and native) proteins is called the membrane theory. A careful examination of past records shows that this theory has no author in the true sense of the word. Rather, it grew mostly out of some mistaken ideas made by Theodor Schwann in his Cell Theory. (This is not to deny that there is a membrane theory with an authentic author but this authored membrane theory came later and is much more narrowly focussed and accordingly can at best be regarded as an offshoot of the broader and older membrane theory without an author.) However, there is no ambiguity on the demise of the membrane theory, which occurred more than 60 years ago, when a flood of converging evidence showed that the asymmetrical distribution of K+ and Na+ observed in virtually all living cells is not the result of the presence of a membrane barrier that permits some solutes like water and K+ to move in and out of the cell, while barring — ab- solutely and permanently — the passage of other solutes like Na+. To keep the membrane theory afloat, submicroscopic pumps were installed across the cell mem- brane to maintain, for example, the level of Na+ in the cell low and the level of K+ high by the cease- less pumping activities at the expense of metabolic energy.
    [Show full text]
  • Bacteria Handle
    Chapter 01 Lecture 1 A Glimpse of History . Science of microbiology born in 1674 . Antony van Leeuwenhoek (1632–1723) • Drapery merchant • Made simple magnifying glass • Studied lake water • Observed ‘animalcules’! . Robert Hooke • Also credited with discovery • Described ‘microscopical mushroom’ (common bread mold) in 1665 Importance of Microorganisms . Microorganisms are Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. foundation for all life on earth Lens . Have existed for ~3.5 Specimen holder billion years . Plants, animals, Focus screw modern microorganisms all evolved from ancestral bacteria Handle . Our life depends on their activities © Kathy Talaro/Visuals Unlimited 1.1. The Dispute Over Spontaneous Generation . Theory of Spontaneous Generation • “Life arises spontaneously from non-living material” • Theory had supporters and detractors • Detractors included – Francesco Redi – Louis Pasteur – John Tyndall • Each contributed to disproving the theory 1.1. The Dispute Over Spontaneous Generation . Italian biologist and physician Francesco Redi . Demonstrated worms on rotting meat came from eggs of flies landing on meat (1668) • Placed meat in two jars • Covered one jar with gauze • Gauze prevented flies from depositing eggs • No eggs no worms . Took another 200 years to convincingly disprove spontaneous generation of microorganisms • One reason: conflicting results between laboratories 1.1. The Dispute Over Spontaneous Generation . Multiple contributions helped define . In 1749, John Needham demonstrated boiled broths still produced microorganisms . In 1776, Father Spallanzani contradicted Needham’s results • Boiled broths longer; sealed flasks by melting necks • Broths remained sterile unless neck cracked . Controversy still unsolved • Some argued heating destroyed “vital force” necessary for spontaneous generation 1.1. The Dispute Over Spontaneous Generation .
    [Show full text]
  • Introduction a Conceptual and Regulatory Overview, 1800–2000
    / Introduction A Conceptual and Regulatory Overview, 1800–2000 Ernst Homburg and Elisabeth Vaupel On 20 April 1895, the Frankfurt physician and surgeon Ludwig Rehn (1849–1930) reported at the annual Congress of the German Society of Surgery (Deutsche Gesellschaft für Chirurgie) in Berlin that he had diagnosed three cases of bladder tumors among a group of forty-five workers from the magenta department of one of the largest German aniline dyeworks, at Hoechst on the Main. In the following years, simi- lar cases were found in other German aniline dyeworks, and, as a result, this form of bladder cancer was soon called “aniline cancer.” It was one of the earliest industrial carcinomas diagnosed with certainty. In the century after this discovery, many other industrial chemicals would be shown to be carcinogenic.1 Magenta had then been produced from ani- line on an industrial scale for almost four decades. It was made in dozens of aniline dyeworks all over Europe and the United States. By 1895, some twenty thousand workers were employed in the German dyestuffs industry alone, along with several thousands in other countries.2 Why was this particular occupational disease discovered so late? Apart from the obvious possibility that entrepreneurs and physicians connected to these factories might not always have been very keen to publish about the health problems among their workers, there are at least four major reasons. First, we now know cancers such as aniline- induced bladder cancer have a latency period of ten to more than twenty years, so the material properties of substances and organisms matter: the workers diagnosed ill in 1895 had been working with aniline already around 1880.
    [Show full text]
  • History of Microbiology: Spontaneous Generation Theory
    HISTORY OF MICROBIOLOGY: SPONTANEOUS GENERATION THEORY Microbiology often has been defined as the study of organisms and agents too small to be seen clearly by the unaided eye—that is, the study of microorganisms. Because objects less than about one millimeter in diameter cannot be seen clearly and must be examined with a microscope, microbiology is concerned primarily with organisms and agents this small and smaller. Microbial World Microorganisms are everywhere. Almost every natural surface is colonized by microbes (including our skin). Some microorganisms can live quite happily in boiling hot springs, whereas others form complex microbial communities in frozen sea ice. Most microorganisms are harmless to humans. You swallow millions of microbes every day with no ill effects. In fact, we are dependent on microbes to help us digest our food and to protect our bodies from pathogens. Microbes also keep the biosphere running by carrying out essential functions such as decomposition of dead animals and plants. Microbes are the dominant form of life on planet Earth. More than half the biomass on Earth consists of microorganisms, whereas animals constitute only 15% of the mass of living organisms on Earth. This Microbiology course deals with • How and where they live • Their structure • How they derive food and energy • Functions of soil micro flora • Role in nutrient transformation • Relation with plant • Importance in Industries The microorganisms can be divided into two distinct groups based on the nucleus structure: Prokaryotes – The organism lacking true nucleus (membrane enclosed chromosome and nucleolus) and other organelles like mitochondria, golgi body, entoplasmic reticulum etc. are referred as Prokaryotes.
    [Show full text]