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71.
Aragno, M. 1996. Des microbes et des hommes, p. 171-187. Natures
en tête, GHK, Musée d'Ethnographie, Neuchâtel.
72. Beffa, T., M. Blanc, and M. Aragno. 1996. Obligately
and facultatively autotrophic, sulfur- and hydrogen- oxidizing
thermophilic bacteria isolated from hot composts. Arch. Microbiol.
165:34-40
73. Beffa, T., M. Blanc, L. Marilley, J. Lott Fischer, P-F. Lyon,
and M. Aragno. 1996. Taxonomic and metabolic
microbial diversity during composting, p. 149-161. In M. De
Bertoldi, P. Sequi, B. Lemmes, and T. Papi (eds.), Blackies Academic
& Professional, London, UK.
74. Beffa, T., M. Blanc, P-F. Lyon, G. Vogt, M. Marchiani, J.
Lott Fischer, and M. Aragno. 1996. Isolation
of Thermus strains from hot composts (60-80°C). Appl.
Environ. Microbiol. 62:1723-1727.
75. Blanc, M., T. Beffa, and M. Aragno. 1996. Biodiversity of
thermophilic bacteria isolated from compost piles, p. 1087-1090.
In M. De Bertoldi and P. Segui (eds.), The science of composting.
Blackie Academic and Professional, London.
76. Fahrni, H-P., M. Gandolla, and C. Fischer. 1996. Politika
gospodarenja otpadom u Svicarskoj (en serbo-croate) Gaspodarstvo
i okolis. Gospodarstvo i okolis 5:431-434.
77. Fischer, C., M. Gandolla, and M. Aragno. 1996. Procesos de
generaction de calor en torno a un vertedero clausurado: causas
del fenomeno y posibles consecuencias para su gestion y seguridad.
Residuos 30:30-38.
78. Fischer, C., M. Gandolla, and M. Aragno. 1996. Heat
generating processes in sanitary landfill: causes of the phenomenon
and possible consequences for landfill management and security.
Rifiuti Solidi 10:323-333.
79. Fischer, C., M. Gandolla, and M. Aragno. Heat-generation in
sanitary landfills: cause of the phenomenon and consequences for
landfill construction, management and security. 1996. Rio de Janerio,
Anais do III SIBESA, Simposio Italo-Brasileiro de Engeharia Sanitaria
e Ambiental ABES.
80. Job, C., J. Keller, and D. Job. 1996. Degradation of unbleached
sulphite pulp paper treated in solid state conditions with five
species of the brown rot Gloeophyllum. Material und Organismen
30:105-117.
81. Job, D. 1996. Environmental growth requirements for sumbsersed
cultures of the ectomycorrhizal fungus Coenococcum geophilum Fr.
Cryptog. Mycol. 17:165-171.
82. Keller, J. and D. Job. 1996. Modern aspects of fungal taxonomy.
Mycol. Helv. 8:73-107.
83. Lott Fischer, J. 1996. Pilzsporen und Kompost. Kompostkrümel
1/96:11-12.
84. Lott-Fischer, J., P-F. Lyon, T. Beffa, and M. Aragno. Composting
of organic garden and kitchen waste in open-air windrows: influence
of turning frequency on the development of Aspergillus Fumigatus.
1207-1210. 1996. The science of composting.
85. Lyon, P-F. Industrial composting of biodegradable
wastes. Proceeding of the conference. 1996. Berne.
86. Marchiani, M. A polyphasic approach of strictly thermophilic
hydrogen- oxidizing bacteria, isolated from several and distant
geothermal areas of the globe. 1996. Thesis, University of Neuchâtel.
87. Nusbaumer, C., D. Job, and M. Aragno. 1996. Etude de l'altération
par les champignons de l'état physico- chimique des composés
lignocellulosiques dans un processus naturel de compostage. Mycol.
Helv. 8:51-67.
88. Prince Sigrist, M-H. and D. Job. 1996. Etudes mycologique,
entomologique et physico-chimique de troncs de Betula pendula
en voie de dégradation. I. Répartition spatiale
de l'état physico-chimique et de la mycoflore des troncs.
Can. J. Bot. 74:1657-1664.
89. Rossi, P., N. Doerfliger, I. Müller, and M. Aragno. 1996.
Traçage des eaux à l'aide de bactériophages.
Gas-Wasser-Abwasser 76:41-49.
90. Balestra, U., C. Fischer, M. Aragno, J. Hunziker, and Z. Sharp.
Stable carbon isotopes as a diagnosis tool of bacterial activity
in landfills and composting systems. ISSM 96, Davos, CH. 1996.
91. Blanc, M., J. Lott Fischer, P-F. Lyon, T. Beffa, and M. Aragno.
Heterotrophic spore-forming bacteria isolated from hot compost
piles. of a poster presentation at the 55th Annual Meeting of
SSM, Bern, CH . 1996.
92. Innocenti, A., F-R Mahrer, C. Rossier, and M, Aragno. Biomethanisation
of organic refuse from restaurants. of a poster presented at the
56th Annual Meeting of SSM, St.Gallen, CH . 1996.
93. Lott Fischer, J. Composting of organic garden and kitchen
wastes in open-air windrows: influence of the turning frequency
on the development of Aspergillus fumigatus. SPP meeting, Bern
. 1996.
94. Lott Fischer, J., T. Beffa, P-F. Lyon, M. Blanc, and M. Aragno.
Composting of organic waste in open-air windrows: influence of
the turning frequency on the development of Aspergillus fumigatus.
of a poster presented at the 56th Annual Meeting of SSM, St.Gallen,
CH . 1996.
95. Lyon, P-F., T. Beffa, J. Lott Fischer, M. Blanc, and M. Aragno.
Eco-physiologie of highliy thermophilic bacteria
isolated from hot compost in switzerland. 56th Annual Meeting
of SSM, St.Gallen, CH . 1996.
96. Rossi, P., K. Formentin, and M. Aragno. Direct assessement
of the behaviour of five bacterial viruses (bacteriophages) in
underground freshwater environments using batch agitated experiments.
of an oral presentation at the 1996 Int.Symposium on Subsurface
Microbiology, Davos, CH . 1996.
72.
Beffa, T., M. Blanc, and M. Aragno. 1996. Obligately and facultatively
autotrophic, sulfur- and hydrogen- oxidizing thermophilic bacteria
isolated from hot composts.
A variety of autotrophic, sulfur- and hydrogen-oxidizing thermophilic
bacteria were isolated from thermogenic composts at temperatures
of 60-80° C. All were penicillin G sensitive, which proves
that they belong to the Bacteria domain. The obligately autotrophic,
non-spore-forming strains were gram-negative rods growing at -80°C,
with an optimum at 70-75°C, but only under microaerophilic
conditions (5 oxygen). These strains had similar DNA G+C content
(34.7-37.6 mol%) and showed a high DNA:DNA homology (70-87%) with
Hydrogenobacter strains isolated from geothermal areas. The facultatively
autotrophic strains isolated from hot composts were gram-variable
rods that formed spherical and terminal endospores, for one strain.
The strains grew at 55-75° C, with an optimum at 65-70°
C. These bacteria were able to grow heterotrophically, or autotrophically
with hydrogen; , they oxidized thiosulfate under mixotrophic growth
conditions (e.g. pyruvate or hydrogen plus thiosulfate). These
strains had similar DNA G+C content (60-64 mol%) to and high DNA:DNA
homology (> 75%) with the reference strain of Bacillus schlegelii.
This is the first report of thermogenic composts as habitats of
thermophilic sulfur- and hydrogen-oxidizing bacteria, which to
date have been known only from geothermal manifestations. This
contrasts with the generally held belief that thermogenic composts
at temperatures above 60° C support only a very low diversity
of obligatory heterotrophic thermophiles related to Bacillus stearothermophilus.
73.
Beffa, T., M. Blanc, L. Marilley, J. Lott Fischer, P-F. Lyon,
and M. Aragno. 1996. Taxonomic and metabolic microbial diversity
during composting.
A great variety and high numbers of aerobic thermophilic heterotrophic
and/or autotrophic bacteria growing at temperatures between 60-80°C
have been isolated from thermogenic (temperature 60-80°C)
composts in several composting facilities in Switzerland. They
include strains related to the genus Thermus (T. thermophilus,
T. aquaticus, and several other new strains), Bacillus schlegelii,
Hydrogenobacter spp., and of course heterotrophic sporeforming
Bacilli. This contrasts with the generally held belief that thermogenic
composts (> 60°C) support only a very low diversity of
heterotrophic thermophiles. This bio-diversity suggests efficient
decomposition of organic matter at temperatures above 60°C,
and a good thermo-hygienization. During the terminal cooling or
maturation phase of composts high numbers and a great metabolic
diversity of mesophilic bacteria was observed, including nitrogen-fixers,
sulfur-oxidizers, hydro-gen-oxidizers, nitrifyiers, and producers
of extracellular polysaccharides or bacterial humin. This microbial
diversityplays an essential role for compost stabilization. It
is suggested that mature compost application improves soil chemistry
and microbiology, and can thus be regarded beneficial for agriculture.
74.
Beffa, T., M. Blanc, P-F. Lyon, G. Vogt, M. Marchiani, J. Lott
Fischer, and M. Aragno. 1996. Isolation of Thermus strains from
hot composts (60-80°C).
High numbers (10(7) to 10(10) cells per g [dry weight]) of heterotrophic,
gram-negative, rod-shaped, non-sporeforming, aerobic, thermophilic
bacteria related to the genus Thermus were isolated from thermogenic
composts at temperatures between 65 and 82 degrees C. These bacteria
were present in different types of wastes (garden and kitchen
wastes and sewage sludge) and in all the industrial composting
systems studied (open-air windows, boxes with automated turning
and aeration, and closed bioreactors with aeration). Isolates
grew fast on a rich complex medium at temperatures between 40
and 80 degrees C, with optimum growth between 65 and 75 degrees
C. Nutritional characteristics, total protein profiles, DNA-DNA
hybridization (except strain JT4), and restriction fragment length
polymorphism profiles of the DNAs coding for the 16S rRNAs (16S
rDNAs) showed that Thermus strains isolated from hot composts
were closely related to Thermus thermophilus HB8. These newly
isolated T. thermophilus strains have probably adapted to the
conditions in the hot-compost ecosystem. Heterotrophic, ovalspore-forming,
thermophilic bacilli were also isolated from hot composts, but
none of the isolates was able to grow at temperatures above 70
degrees C. This is the first report of hot composts as habitats
for a high number of thermophilic bacteria related to thegenus
Thermus. Our study suggests that Thermus strains play an important
role in organic-matter degradation during the thermogenic phase
(65 to 80 degrees C) of the composting process.
78.
Fischer, C., M. Gandolla, and M. Aragno. 1996. Heat generating
processes in sanitary landfill: causes of the phenomenon and possible
consequences for landfill management and security.
Abnormally high temperatures in landfills (even > 60°C)
have been linked to the oxidation of organic matter and/or methane.
Precise knowledge of the various processes involved (physical,
chemical or biological reactions) is lacking and it is impossible
to make adequate previsions.
However, for correct landfill construction and management, it
is essential to acquire a better knowledge of these processes,
of their origins and consequences, so as to adapt the technical
components of a landfill (bottom lining, drainage systems, etc.)
and avoid excessive heating by acting on the gas and leachate
extraction. We present here a pluri-disciplinary study of high
temperatures zones discovered on and near two sanitary landfills
in Switzerland. On-site gas and temperature measurements, a survey
by radio-magnetotelluric resistivity and the designing and study
of a bench-scale model were used to elucidate the processes and
organisms involved in this heat-generation.
85.
Lyon, P-F. Industrial composting of biodegradable wastes. Proceeding
of the conference. 1996. Berne.
Composting is a microbiological, aerobic, self-heating, process
for the treatment of biodegradable wastes, allowing the recycling
of organic matter. Interdisciplinary approaches are necessary
to optimize this highly complex industrial operation. Research
at our laboratory aims at specifically improving the thermogenic
phase of composting. Research is carried out at our laboratory
concerning the isolation and characterization of thermophilic
bacteria active during the hot phase, as well as mesophilic bacteria
active during the maturation phase of the composting process.
Their role in the composting pro-cess and their degradation potential
is evaluated. The knowledge about specific compost bacteria can
be useful to optimize composting of industrial wastes, bioremediation
(co-composting of contaminated soils), degradation of xenobiotics,
and utilization of thermostable enzymes for agro-alimentary and
other industrial applications For our study, we are working together
with several industries, representing some of the most frequently
used composting systems in Switzerland: Most of the compost is
produced in open-air windrow systems. At some installation composting
is done in boxes. There, an aeration system is nessecary to ensure
sufficient oxygenation. The heaps are turned by automatic systems.
At some sites, anaerobic fermentation of unstructured, moisture-rich
kitchen waste is done prior to composting. The biogas produced
is used to furnish energy to the composting plant. Composting
can also be carried out in bioreactors. In field-studies the different
parameters influencing the composting process are analyzed: The
composition of waste, the turning frequency, the aeration cycle,
and the compost humidity. The composting process is closely monitored
by following the evolution of temperature, activity of micro-organisms
(gas concentration), pH, organic matter content, dry weight, C/N,
and other parameters. Simulation of the composting process in
the laboratory can be carried out in a controlled, closed, bench-scale
system, with predefined parameters, allowing a constant monitoring.
The different steps of the composting process (collection of biodegradable
wastes, pro-cessing) as well as the final product can offer certain
health risks. These can be identified by monitoring the concentration
of potentially pathogenic microorganisms (molds and bacteria)
in the compost and in the air.
95.
Lyon, P-F., T. Beffa, J. Lott Fischer, M. Blanc, and M. Aragno.
Eco-physiologie of highliy thermophilic bacteria isolated from
hot compost in switzerland.
A better knowledge of the ecophysiology of highly thermophilic
aerobic bacteria active in compost is essential, because long
periods of high temperatures is the only way to achieve good hygienization.
When the composting process is realized with a good management,
the thermophilic bacteria heat the compost piles and maintain
high temperatures (60 to 80°C) during weeks in the whole material.
We have carried out the study at three levels: full- and bench-scale
composting and liquid culture in bioreactor. The actual conditions
(temperature, gas concentration, pH, ... ) of industrial composting
were monitored. We have analyzed four composting processes and
determined the favorable environments in which highly thermophilic
bacteria are active. Total microbial activity was measured and
new strains were isolated. Bench-scale composting in the laboratory
allowed to quantify the effect of various parameters (raw material,
temperature, aeration, turning) on the bacterial activity and
on the efficiency of the composting process. Cultures of bacteria
isolated from hot compost were performed in a bioreactor. The
growth capacities (growth rate) on different organic substrates
were carried out in a large variety of conditions.
This study is supported by the Swiss National Science Foundation,
project SPP BioTech Module 5 B, no 5002 - 038921.
Project title: Composting of organic wastes: Optimization of the
thermogenic phase to overcome the hygienic and public health hazards.
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