The Occurrence of the Thermophilic Blue-green
Alga, Mastigocladus laminosus, on Surtsey in 1970
RICHARD W. CASTENHO1,Z
l>cpaltrncnt of Biology, IJliivcrsity of Orcgon, IC~~gctic,
Orcgon, U.S.A.
INTRODUCTJON
Although several species of blue-green cllgae
ancI other algae have been reported from rnoist
areas surrounding steam vents on Surtsey, none
of tllese appear to be true therniopl~ilesexhibiting growth optima above 45°C ( S c h ~ ~ a b 1970a,
e,
1970b; Behre & Schwabe, 1969). T h e volcanic
island of Slirtsey was first formed in late 1963 off
the south coast ol Iceland.
Mastzgocladzrs lurntrro~z~s
(Ag.) Cohn is a cosmopolitan therrnophilic blue-green alga (Schwnbe, 1960) and its various forms are very commori
in almost 2111 01 the hot springs and stcam vents
of Iceland ~vllicilhave ;I neutral to alkaline p H
and are below a temperature of about 63-ti4"C
(C:astenholz, 1969a). Trvo very distinct forms are
common in Icelandic ]lot water. One is a seldombranching tricllome which grows at temperatures
constantly as high as (53--(i4"C, thus representing
the npper limit photo~yntheticblue-green alga
of Iceland. T h e o t h e ~is the typical brancliiilg
form ~vhich doer not grow above about 57°C:
(Castenholz, 1969a).
011 June 26, 1970 I exarnillecl several of the
steam vents of Surtsey, particularly those near the
old (or easternmost) crater. Fiom these I collectecl presumptive algal specimens in the moist
ll
terrrperatul es as Iligh as 65" C.
ash ~ v l i ~ crecorded
T h e greatest al)undal~ce01 stearn vents occurred
on the inner (5outhern) slopes of the old crater,
on the Iava Ilats on the southeartern side of the
crater, and within the north-south Iissure createcl
cl~~riilg
the 196G-(57 eruptions. T h e inajor collectiori stations ale n~lmbeledon Fig. 1. Almost
all collections wele exnlnined in the fielcl with
a Gooke-McArthur f~elclmicioscope fitted wit11
a phase contrast system with 400x total magnification. Blue-gr een algal trichomes were quite
abundant in some ol the collectior~s,particularly
Station 2, and most of the material from the
thermal collections looked like the high-temperature form of Mastigocladus. T h e purpose of
this short st~idywas to prove that this material
was illdeed A 4 a s ~ i g o ~ l a d uand
s that i t was capable
01 growth at various temperatures above 45°C
Yig. I . M;lp of Llie norlheaslern portion of Surlscy inclicating
collcctioll st;~tiorisill tile easlcrn crater region.
a n d even at 60°C. For this, culture isolatiolls are based primarily on the culture isolations
ancl growth experinients in the laboratory were rather than the fresh or preserved collections of
ash. Tlie taxonomy of blue-green algae (includcarried out.
Sorne of the hot n~oistareas around steam vents ing fl/la;\ligocladz~s)is currently in a conlused
were ;3 Eairit green color due to the density of state, principally because it has traditionally
blue-green algae. Mosses and other algae were been based solely on morphology, a highly varialso restricted to moist areas near steam vent., able criterion in some groups. Thus, clonal culbut at lower temperatures arid in more protected ture should be used whenever possible together
areas such as the fissure of the 1966-67 t3rup- wit11 collections.
tions (Station 4, Fig.1).
COl,l,EC~TIONS(FIG. 1)
stearn vent on flat ground; ash ternperature
IMATERIALS AND METHODS
58-60°C at lip of orifice; slightly green
T h e collectiorls were macle and treated as follcover - unbranched Mastigocladus-like triows. Sterile vials were used throughout and forchomes in clusters on ash particles.
ceps were resterilized between collections in the
crescent-shape ridge on crater slopes with
high temperature steam of the vents (> 90°C).
vents on and under crest; a = east vent, 40
'The samples containing algal material and rrloist
-50°C (collection site); b = center vents,
ash were stored in darkness at bet~veen15" and
35-50"C, pH 7.8 (cletermined by W. Doe25°C for approximately 12 clays before culture
Inel), slightly green cover of unbranched
enrichlneilt and irolation techniques were apfMastigocLadzi,s-like trichomes; c=west vents,
plied. These conditions 01 storage have proved
45-55°C: and 15-20°C.
quite satislactory tor thermopllilic blue-green
on crater slopes, several vent:s, 45-65" C; 110
algae in past work (see Castenholz, 1969b, 1970).
algae found in collection.
Duplicates 01 some of the sarnples were preser veil
large north-south oriented fissure and crater
with lormalin on the collection day.
froin 1966-67 eruptions; many steam vents
T h e culture techniques used for the samples
at base ancl on walls of fissure; a = steamy
i n my laboratory at the University of Oregon
area on top of north end, < 20°C:, visible
01
were those rtandardly used for the isolatio~~
moss cover; 6 = near t-op of north end, 20
f\.la;\tigocladus (Castenholz, 1969a, 1969b, 1970)
-25"C, crevices in rock wit11 moss and algal
except that medium free 01 combined nitrogen
cover; c = wet wall below steam vents near
was 11ot lequired in these cases for the initial
base of fissure, ca. 55"C:, no visible algal
enrichment of the organism. T h e high-temperacover, but unbr;~nctled i\/lnsligoclnclers-like
lure lorlnr were sought tor, in particular, by the
trichomes in clusters on same ash particles.
methods used.
several steam vents on flat lava flow below
(1). T ~ ~ b eand
s fasks containing rnedinrrr I )
inner wall of crater; a = 45-55"C, unwere inoculated with samples horn 7 oi the colbranched A/lasligocladz~s-liketrichornes and
lectiorls and incubated at 60°C under approximore typical branching f\/lastigocladeu also
mately 2,000 lux (coolzuhite fluorescent lamp,)
on ash particles; 6 = 55-(i5"C:, no algae
- contiiiuorrs light. Sinlilar inot ulations Tvere
found (111 particles.
rnade of all the collections ill liquid medium I )
with incu bations at 45 " C. Some n7cre treated CULTURES
T h e 1esul ts of the or igirinl culture enrichments
similarly at 30°C:.
(2). lnocula iiom almost all collections '~ncl in liquid medium D at 30°, 45", and (50" are
enrichlnent. cultures were also placed or streaked sulnmarized in Table 1. Most collections iricubbut only
o n medium I) solidified 1vith 1.5V/, (w/v) agar ated at 45°C: gave rise to f\/la.stigoclad~~s
in 20x150 mm plastic petri plates. Incubatioris the urlbrai~chedtorm. Two of thc collections of
were primarily at 45"C, but some plates wele material macle below 25°C did not. Almost all
also hclcl at 60°C or 30°C:. Individual trichomes 01 the collections which gave rise toi\4a.stigorladziL~
.cvhich s~rbsequentlyradiated from inoculum as at 45°C also did so when incubated at 60°C. This
motile llorlriogollia or by grolvth piocesses were again was the unbranched "high-temperature"
then easily isolated ~\rith~+7atch-maker'siorceps iorrn. None 01 the collections gave rise to this
e ~ ~
at 30°C:
o n small pieces of agar. These were transferred. foim of iWu~tzgotlaclzl. ~ v h incubated
to liquid rnediuln I) to estaI>lish clone cultures. instead of either oi the higher temperatures.
T h e decisions '1s to xvh,it forms of 1Wcr~llgo- Other filarnentou~and coccoid blue-gr een algae
clndw~were p ~ e s e n at
t the various sites 011 Surtsey came up at 30°C in addition to unicellular ancl
Fig. 2. C:ullr~rcI-S2-m Clolic 3- the non-branching form of Mc2stigocla~lus,originally isolatccl frorrl a 60°C enrichmcut (collcctctl
from st;rtion S-211, 35°-.500(:). (A). grown in colnplete mctiium at 60°C:. (U). g1.own ill complecc nledi~una t 45°C. (C:), grown
in completc m c d i ~ ~ ta1
n 45°C - slow growtll conditions. (D). g r o ~ v nin m c t l i ~ ~lacking
m
combi~lctlllitrogr~la t 4.5OC; dcvelopillg
hcterocysts axe indicatetl.
ITig. 3. (:rrlturc I-S;,-m Clotlc 1- t11c typical I)r;ti~clri~~g
form of ~\~ln,stigor.lnrlrcs,
origi~lallyisolatetl a t 90°C (collected fl.oln slation
S-5;r, 45-55°C:). (A). grou't~ ill cornl~lctelnetlilln~it1 45OC. (B). gl.o1\:11 ill m c t l i ~ ~lackillg
~tl
co1111,itred nitrogel1 at ~ 1 5 ~ C
I ~; c t c ~ o cysts arc itrdicatecl.
TABLE 1
En,richmenl.s of M a s L i g o c l a d z ~ s( M = zcrrbl-anclzed form; A/lt = lypical. brnlzched forrn) (rorn
samples collected al! stations o n Sz~rtsey. A =
othel- blue-green and green algae.
S-4-c (55°C)
S-5a (45-55"C)
Mt,A
M
M
M
-
TABLE 2
(.;ult'~~res
o f iV1asligocladus from Sti~Yseyp3t.esenily m,aintainecl at t h e ZJniversity of Oregon
(No.t~ernber,2.970).
I-Sa-tn
1
45
S-5a
45-55
f . lypicn, branching
docs 1101 grow
colonial green algae. I n one case, holvever ( M a ) , liinit in this case appears to be ;tl~out53OC.
a typical branching Corm 01 Ma~ligoclad~ta
arose Growth also occ~irredat 45" and 30°C.
a t 30°C. This was later isolated arid cloned. 'The
same inocululn gave rise to the unbranched form D1SC:USSTON
Tlle principal resnlt ieported here is simply
of Aclastigoclad?i~at 45°C (Table 1). Marly oi the
enrichments of i l d u ~ t i g o c l a d ~ati ~ 45" and 60°C the occurrence of at least two genetic types of
were 5ubsequently cloned trorn agar plates by i\/lu.\tigorlad~r1s on Surtsey, the filst report o f ;I
rnanually relnoving single trichomes (under a truly thermophilic blue-green alga on this new isdissecting microscope), then inoculating each land. T h e "high-temperature" I-orrn, at least, was
into liquid lnediunl in c u l t ~ ~ rtubes.
e
Although lairly well distributed around no st ol the iteaxrl
several clones of most cultures were successful vents examined (Table 1). This suggests that an
only those listed irl Table 2 have beell retained initial successlul inoculation rnay have occurred
a year or two earlier and that the organism has
in the culture collection.
since spread to other steam vents. This appears
T h e two piincipal iorms of i\/lastigotlndzts
lnrnzno~zisoccurring on Surtsey are illustrated in Inore liltely than the simultaneous inoculation
Fig 2 and 3. T h e species as interpreted by Fremy of several steam vents from a fairly distant source.
At this point it woulcl be inere specrilation to
(1936) ancl Schrvabe (1960) is highly polyrnorphic. However, it may be see11 that even clonal suggest the lnaniler in which A/lasligocla.dz~,sinocell lines are highly plastic in morphology. T h e culul~l was first transported to Surtsey. T h e
grorvth form depends to a large degree on the manner in which most micro-algae are dispersed
environniental t onditions in cul ture ancl on the is largely speculation, but at least there has been
age ot the culture (Castenholz, 1970, and un- some work (see Maynard, 1968; Proctor et a[.,
p~~l)li<lied
data) T h e complications of niorpho- 1067) which indicates that both air ancl birds
logical variability in ll/la~tigocladzi.\ l a r n i ~ z o ~ u sare import;unt long distance agents. I n the case
lanzinos~csancl other true therhave beell most recently cliscussed by Schwabe of il4ustigocladz~~s
(1960) and are also being illvestigatecl at present rnophiles on Surtsey the inoculurn lnrlst have
in my laboratory. Ally further discussion non7, originated fro111 rnainlancl Iceland hot springs
ho.iuever, ~ v o u l dbe out of place lor the pulposes or steam vents and have been carried more or
less directly to the new site. This "rare source"
of this report.
T h e ~lnbranchedforrn (Fig.2) glows ~vellin condition makes such a colorlization a less £reculture at both 60°C and 45°C; grotvth is slo~v, p e n t possibility than that involving more ubihowever, at 30°C. T h e branched Corm (Fig 3) quitously distributed rnesophilic algae, marly of
horn Surtsey did not grow at 60°C:; even at :)5"C which norv occur on Surtsey (Schwabe, 1970,
n o growth was a p p a ~ e n t . T h e upper growth 1972).
There are no thermal waters or steam vents
o n the Westman Islarids of which Snrt5ey is a
part. T h e hot springs closest to Surtsey are approximately 75-90 lirn dist-nnt near the mouth
of 0ltus5, near mid-portioiis of Thj6rs5, and in
the Torlajokull region. There is a single warin
well near the southern slope of Eyjafjallajbkull
which is only about 50 km from Surtsey (Barth,
l950), but it i5 1x11kno.ivn xvhether A4ccsligoc ladlr 5
occurs there.
M a ~ t z g o c l a d u l~a r n ~ n o s ~i,l ~a very hardy species and can tolerate desiccation ancl freezing
(Casteriholz, 19(i9a, 19(i9b, 1970). This 5houlcl allow fairly easy dissemination if a dibpersing agent
is present. T h e world-wide distribution of il'lasiigoclodus in hot springs of- alkalirie to neutral p H
supports the hypothesis that i\/lasligtald~csis oilc
of the most easily dispersed thermopliiles. Thermo-biologists and other scieiitists working in
thermal areas can l~ecomethe priricipal agents
for dispersal of thernlopll ilic mi<i o-organisms if
precautions are riot taken, 5uch as thorough
cleaning ol boots and t ollecting eclniprnerit. Tlie
original intr ocluctiori of Ada.\ tigoc l a c l ~to~ Surtsey
by this rneans caliilot be excludecl.
AC;I<NOWI,EDGEMENTS
T h e ;~rithoris grateful to tlie 13ostoi1 C;ollegc
- NASA Surtsey - Iceland Expedition ancl the
Surtsey Research Society for irialiiiig possible the
collectioils oil Surtsey. T h e U.S. National Scieilcc
Foundation has supported the work clone in my
laboratory.
.References:
I. Bartlr, T. F. Mr.1950. Volcanic geology, hot springs, and
geysers of Iceland. Carncgie Inst. \Vash. Publ. 587, 171
pages.
2. Bchrc, K. and C . I-I. Schwabe. 1969. Algenbcfunde in d r ~ r
I<raterraumen auf Surtsey Island, Som~ncr1968. \~orl2ufigc
Mitteilung a t ~ stlcm MI'I. fiir Limnologie, Plon, 7 pages.
3. C:;tstenllolz, R. Mr. 1 9 6 9 ~ T
. h e thern~opl~lic
cyanoj~hytesof
Icclancl and the upper te~npel.at~rrc
limit J. S'l~ycology 5:
360-368.
4. Castcnlrolz, R. \,V. 196Sb. Tllertnophilic l~lue-greenalgae
and the thermal environmeni. Bactcriol. Iceviews 33:
476-504.
5. C;rsrenholz, 1970. 1,abor;ltory ctrlturc of tlrcrmophilic cyanopllytcs. Schweizcrische z. Hydrologie 32:538--551.
6. Frcmy, 1'. 1936. Remarclues sur la rnorpl~ologieel. la hiologic dc 1' Hapalosiphoii lonzitzosns I-lansg. Ann. Protistologic 5 : 175-200.
7. Maynard, N . G . 1968. Siguificarrcc oE air-bor~lcalgac. %.
Allg. Mikrobiol. 8: 225-226.
8. I'roctor, V. Mr.,C. R. Malonc, a ~ t dV. I,. DeVlaming. 1967.
1)ispersal o f aquatic organisms: viability of clisse~ninules
recovered from the intestinal tract of captive Killdeer.
Ecology 49: 672-676.
I).Schwahe, C;. 13. 19(i0. 6 b e r tlccl thermobiontc~~ICosmolmlitcn Masligoclacl~rs 1c1i?7i~to,s1rs
(:ohn. Blau-Algen ~11rt1
1.cbensraum \I.Scllweizcriscllc %. Hydrologie 22: 757-792.
10. Schwabe, G. H. 1970. On the algal ~ ~ t t l c t n e nint craters
on Surtsey during summer 1968. Surtsey Rcsearch Progress
I<cport V: 68-69.
11. Schwabe, G . FT. 1972. Uluc-green algac as pioneers on
postvolcanic substrate (Surtsey/Iceland). l'roc. 1st Internat.
Sytnposium on 'Taxonomy ant1 Biology of Blue-green Algatr
(in the press).