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The Swimming Behavior of Selected Archaea 1
Bastian Herzog1,2, Reinhard Wirth1* 2
3
1 Archaea Centre, University of Regensburg, Universitätsstraße 31, 93053 4
Regensburg, Germany; [email protected]; phone: 5
+49(0)941/943-1825 6
2 Present address: LS Siedlungswasserwirtschaft, TUM, Am Coulombwall, 85748 7
Garching, Germany; [email protected]; phone: +49(0)89/289-13708 8
9
*: corresponding author at 10
Prof. Dr. Reinhard Wirth, Universität Regensburg, Mikrobiologie – Archaea Centre 11
Universitätsstraße 31, 93053 Regensburg, GERMANY 12
14
running title: archaeal swimming behavior 15
16
key words: Archaea; swimming; Methanocaldococcus villosus; speed 17
18
19
Copyright © 2012, American Society for Microbiology. All Rights Reserved.Appl. Environ. Microbiol. doi:10.1128/AEM.06723-11 AEM Accepts, published online ahead of print on 13 January 2012
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SUMMARY 20
The swimming behavior of Bacteria has been studied extensively, at least for some 21
species like Escherichia coli. In contrast alomost no data have been published for 22
Archaea in this respect. In a systematic study we asked how the archaeal model 23
organisms Halobacterium salinarum, Methanococcus voltae, Methanococcus 24
maripaludis, Methanocaldococcus jannaschii, Methanocaldococcus villosus, 25
Pyrococcus furiosus and Sulfolobus acidocaldarius swim and which swimming 26
behavior they exhibit. The two Euryarchaeota M. jannaschii and M. villosus were 27
found to be by far the fastest organisms reported up to now, if speed is measured in 28
bps (bodies per second). Their swimming speeds, with close to 400 and 500 bps, are 29
much higher than that of the bacterium E. coli, or a very fast animal, like the cheetah, 30
with ca. 20 bps, each. In addition we observed that two different swimming modes 31
are used by some Archaea. They either swim very rapidly, in a more or less straight 32
line, or they exhibit a slower kind of zigzag swimming behavior, if cells are in close 33
proximity to the surface of the glass capillary used for observation. We argue that 34
such a “relocate and seek” behavior enables the organisms to stay in their natural 35
habitat. 36
37
INTRODUCTION 38
The ability to move is of pivotal importance for most organisms; this is especially true 39
for microorganisms which experience many – often dramatic – changes in their 40
natural habitat. A translocation of just 1 cm in water current translates into 10,000 41
body lengths for a bacterium of 1 µm in size (for human a corresponding 42
translocation would be close to 20 km!). Within such a distance concentrations of 43
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potential food sources may differ dramatically in open water bodies, but also 44
temperature differences of > 50° C can occur within 1 cm, e.g. within “black smoker 45
systems”. Therefore, microorganisms able to react to such differences by moving to 46
optimal surroundings have a distinct advantage over those that are immotile. 47
Swimming in liquid media is by far the best characterized motility mechanism in 48
Bacteria, but various other mechanisms of movement on surfaces have been defined 49
for them (see, e.g. 11, 13, 17). 50
Rotation of flagella has been identified early on as the mechanism of swimming in the 51
bacterial model organisms Escherichia coli and Salmonella typhimurium (5). It also 52
has been known for a long time that switching between “runs” and “tumbles” is the 53
mechanism underlying bacterial chemotaxis (16). Today, the bacterial motility system 54
using flagella for swimming has been studied to a great extent and very many 55
aspects are known, not only down to molecular details, but also with respect to 56
regulation (see e.g. 3, 21, 26 for reviews, and references therein). In principle, signals 57
are sensed by arrays of chemoreceptors; a phospho-relay then transmits the signal 58
to the flagellar motor. The sensitivity of the chemoreceptors can be modulated by 59
their methylation, resulting in the possibility of adaptation to stimuli. The presence of 60
chemoattractants leads to longer lasting runs (= linear movement) by 61
counterclockwise rotation of the peritrichously located flagella, which themselves are 62
combined in one bundle. Runs, typically at a speed of ca. 20 µm/s are interrupted by 63
tumbles (= new, accidental orientation in space by disintegration of the flagellar 64
bundle), which are induced by short clockwise rotation of flagella. E. coli, therefore, 65
reacts to attractant/repellent sources by integrating signal intensity over time, and not 66
cell length. It also was found that variations of the “standard E. coli swimming mode 67
system” exist. In the case of Rhizobium meliloti the new swimming direction is not 68
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accomplished by tumbling; rather a short stop of flagellar rotation reorientates this 69
bacterium. 70
In the case of Archaea much less data were reported to their swimming mode. Only 71
in the case of the rod-shaped species Halobacterium salinarum (earlier H. halobium) 72
and quadratic shaped halobacteria has the mechanism of swimming been shown, by 73
dark field microscopy, to be due to rotation of flagella (1, 2). For these Archaea a 74
simple back and forth movement was observed and cells were relatively slow (2 75
µm/s). The movement of Methanococcus voltae has been described to consist of 76
incomplete circles (90 – 270°), interrupted by short stops (K. Jarrell, personal 77
communication and own data, not shown); it has to be mentioned, however that this 78
holds true only if cells are observed at room temperature under aerobic conditions. 79
Direct measurements of the swimming speed of hyperthermophilic microorganisms 80
have not been reported up to now; the archaeum Pyrococcus furiosus for example 81
was named “rushing fireball”, but no comment on its actual swimming speed was 82
given (10). In addition to the limiting data on their swimming speed and mode also 83
only limited data are available for the synthesis, motor components, hook structures, 84
interaction with the chemotaxis system, and other aspects of archaeal flagella (see 85
e.g. 8, 20 for recent reviews). One problem for studies of archaeal flagella clearly 86
relates to the extremophilic nature of archaeal model organisms. Although 87
halobacteria can be grown aerobically at ambient temperatures, studies of their 88
proteins are difficult, due to their salt-dependence. Some members of the 89
Sulfolobales are aerobic, too; in their case however, the dependence on very low pH 90
and high growth temperatures complicate studies. In the case of many 91
hyperthermophilic Archaea, their growth under anaerobic conditions at temperatures 92
above 80° C hinders analyses of their swimming mode. In addition the technique to 93
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observe flagella by direct staining with fluorescent dyes, originally developed for in 94
situ analyses of swimming E. coli (24), is not applicable to a great variety of Archaea 95
(25). 96
Here, we present the first systematic analysis of the swimming mode of selected 97
archaeal model organisms making use of our so-called “thermo-microscope” (12). 98
We asked which swimming patterns these microorganisms exhibit under their optimal 99
growth conditions and determined their swimming speeds. Remarkably, the motility of 100
two species of methanocaldococci is the highest relative speed of any organism on 101
earth. 102
103
MATERIALS AND METHODS 104
Growth of Microorganisms 105
The following microorganisms (species; medium; gas phase; optimal growth 106
temperature) were included in this study: Escherichia coli (fresh fecal isolate), LB, air, 107
37° C; Halobacterium salinarum DSM 3754T, DSM-medium 97, air; 50° C; 108
Methanococcus maripaludis DSM 2067T, DSM-medium 141, H2/CO2 (80/20%), 37° 109
C; Methanococcus voltae DSM 1224T, MGG (4), H2/CO2 (80/20%), 37° C; 110
Methanocaldococcus jannaschii DSM 2661T, MJ (4), H2/CO2 (80/20%), 85° C; 111
Methanocaldococcus villosus DSM 22612T, MGG (4), H2/CO2 (80/20%), 80° C; 112
Methanothermobacter thermoautotrophicus DSM 1053T, DSM-medium 119, H2/CO2 113
(80/20%), 65° C; Pyrococcus furiosus DSM3638T, ½ SME (+ 0.1 % yeast extract + 114
0.1% peptone; 10), N2/CO2 (80/20%), 95 °C; Sulfolobus acidocaldarius DSM639T, 115
DSM-medium 88, air, 70° C. Cells were grown by shaking, aerobically in Erlenmeyer 116
flasks filled to a maximum of 1/10 their nominal volume (E. coli and H. salinarum) or 117
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semi-aerobically in Erlenmeyer flasks filled to 1/3 of their nominal volume (S. 118
acidocaldarius). The other species were grown in 120 ml serum bottles, filled with 20 119
ml medium under the gas phase given above, again with shaking. Growth was in all 120
cases close to stationary phase, a condition under which optimal motility was 121
observed. 122
Cells were transferred into rectangular glass capillaries, 1 x 0.1 mm interior, by 123
capillary action and the capillaries closed on both ends by use of instant super glue. 124
Thereafter the capillaries were immediately transferred onto an electrically heated 125
stage which was placed on the microscope table. Since the capillaries had a length 126
of ca. 3 cm and observations were confined to the center of capillaries, potential toxic 127
effects of super glue were avoided. 128
Microscopic Analyses of Swimming Behavior 129
Analyses were done by use of our so-called “thermo-microscope” (see 12 for a 130
detailed description), which in principle consists of a normal phase-contrast light 131
microscope (Olympus BX50) located inside a plexiglass housing. Heating fans inside 132
this housing were used to heat the system up to ca. 55° C. To obtain higher 133
temperatures the phase-contrast objectives were heated electrically as were the 134
glass capillaries (containing cells) located on the electrically heated stage. Objectives 135
and stage were equipped with temperature sensors to ensure that the desired 136
temperature, which could be raised to a maximum of 95° C, had been obtained. All 137
operation elements like focus, shutters etc. were extended to the outside of the 138
plexiglass housing to allow operation of the microscope at up to 95° C. After the 139
desired temperature was reached (monitored via the heat sensors on the objectives 140
and stage), motility was recorded using a CCD camera (pco1600; PCO Company, 141
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Kelheim, Germany). Movies of swimming microorganisms were analyzed using 142
software ImageJ (ImageJ version 1.41o with Java 1.6.0) with the add-on modules 143
particle tracker and manual tracking. For each movie the diameter of the particles to 144
be analyzed had to be defined; a certain threshold of grey values (maximal deviation 145
of 50%) was used to avoid analyses of microorganisms deviating in the z-plane by 146
more than 2 µm. In some of the supplementary movies tracks which were used for 147
analyses are indicated by coloration. Tracks that consisted of at least five continuous 148
frames were used for determination of maximum swimming speed. Data are only 149
reported for measurements for which the speed calculations for the five frames varied 150
by less than 10%. The average speed was determined by measuring the speed of at 151
least 10 different cells (tracks) of one sample. To further eliminate experimental 152
variations cells were observed in at least 5 independent experiments under the same 153
conditions, especially growth/observation temperature. Therefore, at least 50 tracks 154
were combined for determination of the average speed. For recording the swimming 155
tracks of the fastest organisms a high-speed CCD camera (PCO 1200 hs) with a 156
resolution of 100 frames per second had to be used. Calibration for swimming 157
distances was accomplished by photographing a micrometer scale with the standard 158
equipment used. 159
160
RESULTS AND DISCUSSION 161
The species we have analyzed were selected for the following reasons: The 162
bacterium E. coli was chosen as a positive control because many data are available 163
for this standard bacterium. The archaeum M. thermoautotrophicus was chosen as a 164
negative control, because we knew from earlier analyses (23) that this species is not 165
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motile. The other Archaea were chosen because of their known motility and the fact 166
that they represent model systems for various aspects: H. salinarum for salt-167
dependence; M. maripaludis and M. voltae for mesophilic, genetically manipulable 168
methanogens; M. jannaschii for hyperthermophilic methanogens; M. villosus as a 169
control for the data obtained with M. jannaschii; P. furiosus for heterotrophic 170
hyperthermophilic anaerobic Archaea; S. acidocaldarius for thermoacidophilic 171
Archaea. 172
Control experiments (data not shown) indicated that no difference in swimming 173
behavior was observed if cells were transferred into the rectangular glass capillaries 174
under anaerobic or aerobic conditions. For ease of operation, glass capillaries 175
therefore were filled under aerobic conditions and closed on both ends by superglue. 176
This procedure took less than 1 min and the medium was still anaerobic inside the 177
glass capillaries as indicated by a lack of coloration of the redox indicator resazurin 178
used in the anaerobic media. Table 1 gives a summary of the results obtained, which 179
we interpret as follows. 180
Swimming speeds 181
We did observe an extensive range of swimming speed for the various species 182
analyzed, with absolute values for maximal speeds ranging from 10 to ~ 590 µm/s; 183
average speeds varied from 3 to ~ 380 µm/s. The average swimming speed we 184
observed for our E. coli fecal isolate did exceed with ~ 45 µm/s that reported for E. 185
coli AW405 with 21 µm/s (6). It has to be emphasized that the experimental setups 186
differ markedly between these two data sets: we did analyses at 37° C, enhancing 187
swimming speed by ca. a factor of 1.5 compared with swimming at room temperature 188
(data not shown) and in rich medium, which clearly shifts runs to longer times (6; and 189
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own observations, data not shown). An absolute average swimming speed of 45 190
µm/s translates into a relative swimming speed of ca. 20 bps for E. coli. The 191
maximum speed of the sulfur bacterium Thiovulum majus was reported to be approx. 192
600 µm/s, but because of its size of ~ 7 µm this relates to ca. 85 bps (9). In contrast, 193
the bacterium Bdellovibrio bacteriovorus swims at approx. 100 µm/s which due to its 194
small size relates to a maximum of approx. 150 bps (9). 195
The average absolute swimming speeds we have measured here for the various 196
archaeal model species are in the range of very slow swimming (3 µm/s for H. 197
salinarum, corroborated by earlier data, 1) to very fast swimming (380 µm/s for M. 198
jannaschii). There was no correlation between swimming speed and growth 199
temperature: M. voltae grown at 37° C swims faster than P. furiosus observed at 95° 200
C, but slower than M. villosus grown at 80° C. The maximal swimming speed of M. 201
jannaschii with 589 µm/s is similar to that of T. majus; due to the marked difference in 202
size between those two microorganisms their relative swimming speeds, however 203
differ drastically: ca. 390 bps vs. ca. 85 bps. Because of its smaller size M. villosus 204
has an even higher maximal relative swimming speed of ~ 470 bps. These two 205
archaeal species therefore possess the highest relative speed measured for any 206
organism on earth up to now (15). 207
Mode of swimming 208
The fresh fecal isolate of E. coli was used here for comparisons and showed the 209
mode of swimming reported earlier: runs were interrupted by tumbles. We noted that 210
the swimming speed (45 µm/s) and length of runs (up to 250-300 µm, and up to 8-10 211
s) of this fresh isolate exceed those reported for E. coli AW405 (21 µm/s, and ~ 1s; 212
6). This very probably is due not only to different experimental set-ups (see above), 213
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but also to the fact that E. coli K12 strains have a “lab history” of > 50 years, a period 214
in which physiological alterations might have accumulated. We have deliberately 215
chosen to compare the fresh fecal E. coli isolate with the archaeal species tested, 216
because all of the latter were type strains, representing “wild-types”. 217
Very interestingly, these Archaea (Methanococcus maripaludis, Methanococcus 218
voltae, Methanocaldococcus jannaschii, Methanocaldococcus villosus, Sulfolobus 219
solfataricus) exhibited a swimming behavior we observed also for P. furiosus, which 220
is in stark contrast to that of, for example, E. coli. This latter bacterium swims in more 221
or less smooth runs, disrupted by tumbles to alter the swimming direction. The 222
hyperthermophilic Archaea, on the other hand exhibit a swimming behavior best 223
characterized as a “relocate and seek” strategy; for relocation they swim in more or 224
less straight lines, covering a (relatively) long distance due to their high swimming 225
speed – see supplementary movies. In this fast swimming mode some smaller 226
changes in direction are observed, but not abrupt ones; thus, tumbles observed in E. 227
coli are not observed in these Archaea. For comparative reasons these 228
supplementary movies show: swimming of E. coli (medium velocity- 2 movies, one 229
without and one with indication of tracks used for analyses); swimming of H. 230
salinarum (slow velocity) and swimming of H. salinarum at 10-fold time lapse; 231
swimming of P. furiosus (fast swimming); swimming of M. voltae (fast swimming); 232
swimming of M. villosus (very high velocity); swimming of M. jannaschii (highest 233
velocity). This type of swimming behavior was observed especially for cells swimming 234
parallel to the observation plane in the middle of the capillary. Most of these cells, 235
therefore, did not experience a contact of their flagella with the glass capillary wall; in 236
average, they had a distance of ca. 50 µm from the glass capillary wall. 237
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In addition, the fast swimming coccoid Archaea, however, also exhibited another 238
mode of swimming, namely a much slower kind of zigzag movement – see e.g. 239
supplementary movies for M. jannaschii, M. villosus and P. furiosus. Such a 240
swimming behavior was very rarely observed for cells swimming in the middle plane 241
of the capillary, but was much more often seen in cells swimming near the glass 242
capillary wall, especially if the focal plane was <10µm from the glass capillary wall. 243
We argue that in these cells the zigzag “seek” movement is triggered by close 244
contact with the capillary surface. Taken together this behavior indicates to us that 245
swimming in these Archaea can alter between very rapid relocate movements to 246
bring cells into another surrounding, or much slower seek movements that result in 247
the cells staying in a locally restricted area. The fast linear movements are thought to 248
result in a rapid change of location, to avoid conditions detrimental for growth. The 249
slow zigzag movements are thought to represent a “seek strategy”, followed by 250
attachment to a surface. Indeed, such attachments were observed in our experiments 251
only for cells exhibiting the slow zigzag movement, though not every zigzag 252
movement resulted in adhesion. The zigzag movements reduced the overall 253
swimming speed of the Archaea drastically: for M. jannaschii reduction was from 500 254
µm/s for fast linear “relocation swimming” to 80-100 µm/s, in some cases even down 255
to 50 µm/s for the zigzag “seek movement”; for M. villosus reduction was from 400 256
µm/s down to 100-120 µm/s; for P. furiosus reduction was from 110µm/s to 35-45 257
µm/s; and in the case of M. maripaludis reduction was from 25 µm/s to below 10 258
µm/s. 259
We want to stress that we have shown P. furiosus (19) and M. villosus (4) to be 260
ideally adapted for this “relocate and seek” strategy of motility, because we have 261
proven that their flagella are used not only for swimming, but also for adhesion; the 262
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same very recently was shown to be true for M. maripaludis (14). It has to be noted 263
that all our experiments were done under conditions in which cells did not experience 264
any gradient, with respect to temperature, attractant/repellent concentrations, O2-265
tension, etc. Further experiments will address the question on the distribution of 266
relocation and seek movements of cells experiencing such gradients; this, however, 267
will need the construction of special swimming chambers in which such gradients can 268
be established. 269
270
CONCLUSIONS 271
A beetle obviously cannot move as fast as a man, who on the other hand runs much 272
slower than a cheetah. The question which of these organisms is the fastest should, 273
for a fair comparison, take into account their body size. Therefore, the relative 274
measurement of speed as ‘bodies per second’ (bps = translocation of body sizes per 275
second) has been introduced. Via this definition the following absolute and relative 276
speeds have been measured (15): the maximal speed of a cheetah is 113 km/h or 20 277
bps, the maximal speed of humans is 45 km/h or 11 bps, but the tiger beetle can run 278
at up to 3 km/h, equaling 150 bps. Peregrine falcons can “dive in the air” at up to 300 279
bps; this, however, does not represent an active movement. Clearly, size matters 280
very much in this respect, and therefore, microorganisms come into play here. The 281
swimming speed of Escherichia coli was reported to be 20-25 µm/s, or approx. 20 282
bps (18). As Table 1 shows two species of the genus Methanocaldococcus, namely 283
M. jannaschii and M. villosus turned out to be the fastest organisms observed to date, 284
with maximal speeds of close to 400 and 500 bps, respectively. Our data not only 285
disprove the idea that Archaea in general might swim slower than Bacteria (7), they 286
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even identified the hyperthermophilic archaeal species M. jannaschii and M. villosus 287
as the fastest organisms observed up to date! 288
The “relocate and seek” strategy of motility we observed for the hyperthermophilic 289
Archaea very well could be explained by the conditions these microorganisms are 290
confronted with in their biotope, namely very steep gradients of temperature, for 291
example. A passive translocation for only one second by a water flow of only 10 cm/s 292
would transport the cells (having a diameter of approx. 1 µm) 105 cell diameters 293
away. Even if they were able to swim with 100 µm/s in a continuously unidirectional 294
motion – which has not been observed in microorganisms up to now (18) – it would 295
take them 1000 s (= 16.6 min) to relocate into their original habitat. Direct water flows 296
in black smokers, indeed, are with 1- 2 m/s much higher; water emanating through 297
the chimney wall, however, flows at reduced velocity. Nevertheless a translocation of 298
10 cm would confront the cells with aerobic conditions and low temperature, a 299
situation detrimental to their swimming ability. A repeated change between relocation 300
and adhesion would enable the cells to seek for and stay in a favorable surrounding 301
and therefore be of great advantage for them. We argue that the ability to use one 302
and the same surface structure, namely flagella, for moving in a certain surrounding 303
and to adhere to this surrounding is a remarkably clever strategy to live in such 304
extreme habitats like black smokers. In the case of black smokers cells would adhere 305
in a region of the porous chimney walls which has their optimal growth temperature, i. 306
e. between the outer surface (close to 4° C) and the inner surface (300 – 400 ° C). 307
The distribution of extremophiles in different microhabitats – surface, porous layer, 308
hard layer, etc. – of black smoker chimneys, indeed, has been reported to vary (22). 309
310
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ACKNOWLEDGEMENTS 311
This work was supported in part by DFG grant WI 731/10-1 to RW. We thank E. 312
Gagen and G. Wanner for critically reading the manuscript. 313
314
REFERENCES 315
1. Alam, M. and D. Oesterhelt. 1984. Morphology, Function and Isolation of 316
Halobacterial Flagella. J. Mol. Biol. 176:459-475. 317
2. Alam, M., M. Claviez, D. Oesterhelt, and M. Kessel. 1984. Flagella and 318
motility behaviour of square bacteria. EMBO J. 3:2899-2903. 319
3. Anderson, J. K., T. G. Smith, and T. R. Hoover. 2010. Sense and sensibility: 320
flagellum-mediated gene regulation. Trends Microbiol. 18:30-37. 321
4. Bellack, A., H. Huber, R. Rachel, G. Wanner, and R. Wirth. 2011. 322
Methanocaldococcus villosus sp. nov., a heavily flagellated archaeon adhering 323
to surfaces and forming cell-cell contacts. Int. J. Syst. Evol. Microbiol. 324
61:1239-1245. 325
5. Berg, H. and R. A. Anderson. 1973. Bacteria swim by rotating their flagellar 326
filaments. Nature 245:380-382. 327
6. Berg, H. C. and D. A. Brown. 1972. Chemotaxis in Escherichia coli analysed 328
by Three-dimensional tracking. Nature 239:500-504. 329
7. Brock. 2009. Biology of Microorganisms (Pearson, San Francisco, Int. Edition 330
– ed. 12), page 99. 331
on April 4, 2019 by guest
http://aem.asm
.org/D
ownloaded from
15
8. Ellen, A. F., B. Zolghadr, A.M. J. Driessen, and S-V. Albers. 2010. Shaping 332
the Archaeal Cell Envelope. Archaea 2010: Article ID 608243 333
9. Fenchel, T. 1994. Motility and chemosensory behavior of the sulphur 334
bacterium Thiovulum majus. Microbiology 140:3109-3116. 335
10. Fiala, G. and K. O. Stetter. 1986. Pyrococcus furiosus sp. nov. represents a 336
novel genus of marine heterotrophic archaebacteria growing optimally at 337
100°C. Arch. Microbiol. 146:56-61. 338
11. Henrichsen, J. 1972. Bacterial surface translocation: a survey and a 339
classification. Bacteriol. Rev. 36:478-503. 340
12. Horn, C., B. Paulmann, G. Junker, and H. Huber. 1999. In vivo observation 341
of cell division of anaerobic hyperthermophiles by using a high-intensity dark-342
field microscope. J. Bacteriol. 181:5114-5118. 343
13. Jarrell, K. F., and M. J. McBride. 2008. The surprisingly diverse ways that 344
prokaryotes move. Nature Rev. Microbiol. 6:466-476. 345
14. Jarrell, K. F., M. Stark, D. B. Nair, and J. P. J. Chong. 2011. Flagella and 346
pili both are necessary for efficient attachment of Methanococcus maripaludis 347
to surfaces. FEMS Microbiol. Lett. 319:44-50. 348
15. Lenz, P. H. 2009. Animal Olympians. 349
http://www.pbrc.hawaii.edu/~petra/animal_olympians.html and references 350
therein. 351
on April 4, 2019 by guest
http://aem.asm
.org/D
ownloaded from
16
16. Macnab, R. M. and D. E. Koshland, jr. 1972. The Gradient-Sensing 352
Mechanism in Bacterial Chemotaxis. Proc. Nat. Acad. Sci. (USA). 69:2509-353
2512. 354
17. Mattick, J. S. 2002. Type IV Pili and Twitching Motility. Annu. Rev. Microbiol. 355
56:289-314. 356
18. Mitchell, J. G. and K. Kogure. 2006. Bacterial motility: links to the 357
environment and a driving force for microbial physics. FEMS Microbiol. Ecol. 358
55:3-16. 359
19. Näther, D. J., R. Rachel, G. Wanner, and R. Wirth. 2006. Flagella of 360
Pyrococcus furiosus: multifunctional organelles, made for swimming, adhesion 361
to various surfaces and cell-cell contacts. J. Bacteriol. 188:6915-6923. 362
20. Ng, S. Y. M., B. Zolghadr, A. J. M. Driessen, S-V. Albers, and K. F. Jarrell. 363
2008. Cell Surface Structures of Archaea. J. Bacteriol. 190:6039-6047. 364
21. Porter, S. L., G. H. Wadhams, and J. P. Armitage. 2011. Signal processing 365
in complex chemotaxis pathways. Nature Rev. Microbiol. 9:153-165. 366
22. Takai, K., T. Komatsu, F. Inagaki, and K. Horikoshi. 2001. Distribution of 367
Archaea in a black smoker Chimney Structure. Appl. Env. Microbiol. 67:3618-368
3629. 369
23. Thoma, C., M. Frank, R. Rachel, S. Schmid, D. Näther, G. Wanner, and R. 370
Wirth. 2008. The Mth60 fimbriae of Methanothermobacter 371
thermoautotrophicus are functional adhesins. Environ. Microbiol. 10:2785-372
2795. 373
on April 4, 2019 by guest
http://aem.asm
.org/D
ownloaded from
17
24. Turner, L., W. S. Ryu, and H. C. Berg. 2000. Real-time imaging of 374
fluorescent flagellar filaments. J. Bacteriol. 182:2793-2801. 375
25. Wirth, R., A. Bellack, M. Bertl, Y. Bilek, T. Heimerl, B. Herzog, M. Leisner, 376
A. Probst, R. Rachel, C. Sarbu, S. Schopf, and G. Wanner. 2011. The 377
Mode of Cell Wall Growth in Selected Archaea Follows the General Mode of 378
Cell Wall Growth in Bacteria - An Analysis using Fluorescent Dyes. Appl. 379
Environ. Microbiol. 77:1556-1562. 380
26. Yonekura, K., S. Maki-Yonekura, and K. Namba. 2003. Complete atomic 381
model of the bacterial flagellar filament by electron cryomicroscopy. Nature 382
424:643-650. 383
384
385
386
387
SUPPLEMENTAL MOVIES 388
Nearly all movies were recorded using a (electrically heated) 40x objective on the 389
thermo-microscope to observe a large field of view. This was especially important for 390
the fast organisms, to visualize their extreme fast motion and long swimming 391
distance, their very abrupt change of direction and stops. 392
393
Escherichia coli fecal isolate 394
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Escherichia coli fecal isolate, grown in M9 medium at 40° C. Motility was observed 395
from room temperature to ca. 55° C (but only for short time at 55° C), with an 396
optimum at 40° C. Two movies (one without and one with indicated tracks used for 397
analyses) are shown. 398
399
Halobacterium salinarum 400
Halobacterium salinarum, grown in DSM-medium 97 at 50° C. Motility was observed 401
between 21° C to 70° C, with an optimum at 50° C. Two movies (one in original 402
speed and one in 10x time lapse) are shown. 403
404
Pyrococcus furiosus Vc1 405
Pyrococcus furiosus Vc1, grown at 95° C in ½ SME medium, supplemented with 0.1 406
yeast extract and peptone, each. Motility was highest at 95° C (maximal temperature 407
we could obtain) and started between 75° C to 80° C. Two movies (one with 408
“relocate” and one with “zigzag movements”) are shown. 409
410
Methanocaldococcus jannaschii JAL1 411
Methanocaldococcus jannaschii JAL1, grown at 85° C in MGG medium. Motility was 412
optimal at 80° to 85° C; slow motility was observed already at 30° C. Two movies 413
(one with “relocate” and one with “zigzag movements”) are shown. 414
415
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Methanocaldococcus villosus KIN24-T80 416
Methanocaldococcus villosus KIN24-T80, grown at 80° C in MGG medium. Motility 417
was optimal at 80° to 85° C; slow motility was observed at 50° C. Two movies (one 418
with “relocate” and one with “zigzag movements”) are shown. 419
420
Methanococcus voltae SB 421
Methanococcus voltae SB, grown at 37° C in MGG medium. Motile between 30 to 55 422
° C, with an optimum between 35 to 45° C; one movie is shown. 423
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Table 1: Swimming characteristics of various Archaea
Species Shape/
Size Optimal growth
temperaturea
Average velocityb
[µm/s]
Maximal velocity [µm/s]
Zigzag movement observed
Velocity in zigzag
movementc [µm/s]
Temperature range of
swimming
Mode of swimming / Remarks
Escherichia coli Rod / 2 x 0.7 µm 37° C 45 +-5.0 66 - - 20 – 60° C Smooth curves and smooth lines,
interrupted by tumbles. Halobacterium salinarum
Rod / 10 x 1 µm 50° C 3 +- 0.5 10 - - 20 – 65° C Slow smooth lines; swimming speed
markedly dependent on temperature. Methanococcus voltae Coccus / 2
µm 37° C 80 +- 8.5 128 + n.d. 20 – 55° C Rapid and long, notched tracks; shearing has no big influence on swimming capacity.
Methanococcus maripaludis
Coccus / 1.5 µm 37° C 25 +- 3.4 45 + < 10 20 – 60° C Short, notched tracks; extremely
sensitive to shearing. Methanocaldococcus jannaschii Coccus /
1.5 µm 85° C 380 +- 40 589 + 50-100 20 – 90° C Extremely fast, directional swimming, or slower zigzag movement; very slow swimming at room temperature.
Methanocaldococcus villosus
Coccus / 1 µm 80° C 287 +- 36 468 + 80-120 50 – 90° C Very fast directional swimming or
slower zigzag movement. Pyrococcus furiosus Coccus /
2.5 µm 100° C 62 +- 7.0 110 + 30-50 70 – 95° C Swimming markedly dependent on temperature; directional swimming and slower zigzag movement.
Sulfolobus acidocaldarius Coccus /
1.5 µm 70° C 45 +- 4.2 60 - - 30 – 80° C Swimming speed markedly dependent on temperature; notched tracks with zigzag elements.
a: The data given for average velocity and maximal velocity were determined for this temperature.
b: The values given in Table 1 represent the mean of at least 50 independent swimming tracks (at least 10 cells measured in 5 independent experiments - see Materials and Methods). The given standard deviation is derived from tracks that differed for not more than 10% from each other. Also included in the sd values are experimental setup related error sources like the tracking of “diving” cells, or problems with program calibration.
c: n.d. not determined
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