Cyanobacteria, li le-known but common in aquarium

Cyanobacteria, li•le-known but common in
aquarium
Text & photos:
José María Cid Ruiz
When it was discovered the dis!nc!on between prokaryo!c
cell (cell without nucleus) and eukaryo!c (cell with nucleus), it
was found that the living organisms currently called
"cyanobacteria" were not true algae. Cyanobacteria are in
fact, the only prokaryo•c organisms capable to do oxigénic
photosynthesis1.
Main features of cyanobacteria
Cyanobacteria (badly named
ed "green-blue algae") are unicellular
organisms. They are able to perform photosynthesis and the
therehere
he
re-re
fore synthesize their own food (autotrophs). Like the tr
algae,
true
ue alg
lgae
lg
ae,
ae
teri
riaa have
ri
ha chlorophyll and also a set
set of secondary
ssec
econ
ec
onda
on
dary
da
ry p
pig
igig
cyanobacteria
pigments:
phycocyanin,
s: phy
hyco
hy
cocy
co
cyan
cy
anin
an
in, alophycocyanin (blue
in
ue pigment)
pig
p
igme
ig
ment
me
nt)) and
nt
and phyphycoerythrin ((re
red
re
d pi
pigm
gmen
gm
ent)
en
t). These
Thes
Th
esee last
last pigments,
pigme
ment
me
nts,
nt
s, have
hav
h
ave th
av
the func!on
(red
pigment).
of capturing energy
eene
nerg
ne
rgyy from
rg
from the
the light that
tha
hatt is then
the
hen
he
n absorbed
ab
by the
lorophyll-a. All
All of
of these
thes
th
esee photosynthe!c
es
phot
ph
otos
ot
osynthe!
os
e!c compounds are not
chlorophyll-a.
osed in membranes
memb
me
mbra
mb
rane
ra
ness by way
ne
way off chloroplasts
chloro
ch
roplasts (as in true algae),
enclosed
a#ered
ed in thee pr
prot
otop
ot
opla
op
lasm
la
sm of
of the
th cell.
cellllll. Cyanobacteria have
ce
are sca#ered
protoplasm
surr
rrounded by
b a mucilaginous
muci
mu
cila
ci
lagi
la
gino
gi
nous
no
us layer
llay
ayer (viscose)
ay
((vi
visc
vi
scos
sc
ose) composed
os
cell wall surrounded
of mucopolysaccharides
ysac
ys
accharid
ides
es and
nd pec!nics
pec
ec!n
ec
!nic
!n
ics acids.
ic
s. The
The protoplasm
proto
topl
to
plasm of
pl
pres
pr
esen
ents
ts aamo
mong
mo
ng other
oth
ther organelles:
th
org
o
rganelles: ribosomes,
rg
rib
ibos
ib
osomes, vaos
cyanobacteria presents
among
poligl
gluc
gl
ucan
uc
anos and
an
nd cianoficina.
cciano
nofic
no
ficina.
fic
cuoles, granules of poliglucanos
udies performed
perfor
pe
ormed with
or
th this
tthi
his group
hi
grou have deterDifferent gene!c studies
ia typ
ype Gram-nega!ve.
yp
Gram-nega!v
mined that they are bacteria
type
Cyanobacteria, li•le-known
own but common in aquarium
cyanob
Many species of cyanobacteria
present a mixed metabolism. They, not only are able to generate organic com
compounds through photosynthesis, also can fix atmospheric nitrogen (N 2)
dissolved in the
t water. This last process is performed by cyanobacteria using an enzyme
which breaks
the molecule of the gas nitrogen and forms ammonium (NH4 +), which is albr
read directly metabolized as food. Both processes are incompa!ble simultaneously (the
ready
enzyme used in nitrogen fixa!on is inhibited in the presence of oxygen), therefore cyanobacteria carry out photosynthesis during the day and fixa!on of nitrogen by night.
Cyanobacteria have played a key role in how life evolved on Earth, given that they belong to
the original group of living organisms, responsible for the massive presence of oxygen in the
Earth's atmosphere.
1
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©José María Cid 2014
Cyanobacteria in the aquarium
An organism that is able to survive during the day with a li!le bit
of light and that s"ll feeding at night with nitrogen from the atmosphere (nitrogen dissolved in the water), does not seem to
need much addi"onal help to se!le in an aqua"c environment as
it is a freshwater or marine aquarium. They are in fact almost
always present although not detect them at a glance. The problem comes, when in the aquarium there is a significant
cant imbalannic carbon, nitrace by excess of energy: chemical (excess of organic
tes, phosphates, silicates) or light (excess off luminous radia"on).
In marine aquariums for example,, in a natural process of
ve as some surfaces and especially
ly
"maturing", we would observe
the substrate is moderately
ately colonized by a so$ mono-layer of
(the
(t
hese
he
se aallbrownish algae, due to ini"al coloniza"on by diatoms 2 (these
off th
thee level
leve
le
vel of
ve
gae does not present great requirements in terms o
luminous
us radia"on
r
and take advantage of
of the
the silicon
sililico
si
con
co
n available
avai
av
aila
ai
labl
la
blee in
bl
uari
ua
rium
ri
um’s
um
’s water for its incorpora"on
incorpo
pora
po
ra"o
ra
"on
"o
n into
into their
tthe
heir
he
ir cell
ccel
elll walls).
el
walls)
s). In
s)
thee aqua
aquarium’s
lanc
nced
nc
ed aquarium,
aaqu
quar
qu
ariu
ar
ium, the situa"on would
iu
woul
wo
uld
ul
d be stabilized
ssta
tabi
ta
bilililized in a few
bi
a bala
balanced
On
n th
thee co
cont
ntra
nt
rary
ra
ry, if the ene
ry
nerg
rgy so
rg
sour
urce
ur
cess men"oned above
ce
weeks. O
contrary,
energy
sources
seco
se
cond
co
nd wave
wav
w
ave of cyanobacteria
av
cyanoba
bact
cteria (and later or simultaabound, a second
anot
an
othe
ot
herr of filamentous
he
fila
fi
lame
la
mentou
me
ouss green
ou
gree
een algae) will be developed.
neously another
anobac
acteria are
ar ab
able
le to
o firmly
firml
fir
mlyy be a!ached
ml
a!a
!ach
!a
ched to virtually any surfach
Cyanobacteria
ce inside
idee the aquarium
aqua
uarium
ua
um (including
(in
incl
in
clud
udin
ud
ing living
in
lilivi
ving
vi
ng "ssue).
"ssue
"
ue).
ue
). There
T
they grow,
oduc
od
uced and
nd produce
pro
rodu
ro
duce
du
ce extracellular
ext
xtra
xt
racellular polymers
ra
pol
p
olym
ol
ymer
ym
erss from each
er
are reproduced
he fixing
fixi
fi
xing
xi
ng surface.
sur
urface
ur
ce. Over
ce
Over "me,
"
single cell to the
they will form a consisobiolo
ob
logical structure
lo
stru
st
ructur
ru
ure ("biofilm").
ur
("biofilm") This
Th structutent layer likee a microb
microbiological
ish or b
brown
wnish film"
wn
film
lm"" we are accustomed
lm
acc
re is the "greenish
brownish
to
bstrate,
e, plants
pla
lants or rocks in aquariums
la
aq
seeing on the substrate,
with high
unba
un
balanced in its energy balance.
ba
levels of pollu"on and unbalanced
Cyanobacteria, li•le-known but common in aquarium
It is not always easy to determine that groups or species cons"tute the "biological pollu"on"
aqua
of an aquarium.
O$en bacteria, cyanobacteria and "true algae", share the invasion and the
comp tapestry that can cover the sand at the bo!om, the rocks on the substrate, "ssue of
complex
corals and sponges and even colonize the body of fishes like seahorses (Hippocampus spp).
As a general rule, not rigorous, can be considered that the viscous layers of reddish, brownish
or black shades correspond to cyanobacteria (though the same species may have different
appearances under different ligh"ng spectra or nutrients), while arborescent appearance in
greenish layers typically correspond to invasions of filamentous algae, where are frequent
genus Debersia and Bryopsis, which in turn are not easy to differen#ate from cyanobacteria
of the genus Lyngbya.
2
All rights reserved:
©José María Cid 2014
Also, in presence of silicon in excess, a tapestry of diatoms (true
algae) may be cons!tuted and replace and "bury" a first coloniza!on of cyanobacteria. Some!mes the scenario is complicated further, when together with cyanobacteria and diatoms, is confirmed
under the microscope the massive presence in the water of the
aquarium of pelagic algae (dinoflagellates). The la•er are more
at
difficult to control than the groups men!oned before, given that
not required for survival or nitrogen or phosphorus. They survive
simply with the calcium carbonate from seawater.
How to control its massive expansion
on in the aquarium?
The first ques!on would be:
e: how to control the "what"?. As we saw
aw
on is not always easy to know what we're
re d
dea
ea-ea
in the previous sec!on
dealing and frequently
tly the invasive biofilm not always corresponds
corr
rres
rr
espo
es
pond
po
ndss to
nd
up of organisms. When set up plans
ns to
to deal
deal with
wit
ith
it
h a masmasa single group
sive coloniza!on,
oloniz
iza!
iz
a!on
a!
on, we should know whether
on
wheth
ther
th
er we
we face
face a "plant"
""pl
plan
pl
ant"
an
t" a
"bacteria"
a", a "d
a"
"din
inofl
in
oflag
ofl
agellate" or several
ag
al o
off them
them simultaneously.
ssim
imul
im
ulta
ul
taneously. A
ta
"bacteria",
"dinoflagellate"
good way to
to start
star
st
artt the
ar
the diagnosis
diag
di
agnosis is to
ag
to inves!gate
inves!
s!ga
s!
gate
ga
te which
w
is the source
of uncontrolled
uncontrolle
led
le
d energy.
ener
en
ergy
er
gy.. For
gy
For example,
ex
if
if we find
find high levels of silica0.2 mg / are
re aabl
ble to trigger
bl
t
er massive coloniza!on) we
tes (levels ≥ 0.2
able
ectt that
at wee ar
aree fa
faci
cing
ci
ng with
th a coloniza!on of diatoms. Almay suspec
suspect
facing
th case,
e, it should
shou
sh
ould
ou
ld be measured
mea
m
easu
ea
sure
red
d not
no only the level of
though in this
n the
th aquarium’s
aqua
uari
rium
ri
um’s
um
’s water
wat
w
ater
at
er but
b also
als
lso
ls
o measure
measur
me
uree the
ur
th same parasilicates in
he ffre
reshwate
ter us
te
used
ed. Th
ed
This recommenda!on
rrec
ecommend
ec
nda!
nd
a!on
a!
on is
is because the
th
meter in the
freshwater
used.
diatoms incorporate
rporate very
very quickly
qui
uickly the
ui
the silicon
silililic
icon available in the aquaic
aq
some!m
!mes tthe
!m
he level
el o
of silicates
silililica
cates in the aquarium
ca
a
rium water and some!mes
is
he fresh
sh water
wat
ater used to replenish the evaporated
at
not alarming but the
ts used
d to make
m
water or the sea salts
marine w
water present meaningful levels of silicates
Cyanobacteria, li•le-known but common in aquarium
Let's see now, some ac!ons to control this type of "pests" in aquarium :
Eliminate zones prone
pron to be colonized changing its condi!ons. It is generally observed that the
areas of the aqu
aquarium with void or weak stream of water show accumula!on of detritus and
are the an
anchor points of coloniza!on, especially if those areas are exposed to strong light. Genera moderate water flows in every corner where usually accumulate organic debris will
nerate
hinder the establishment of the first colonies in these vulnerable areas.
If pests are developed usually in an aquarium that has an efficient filtra%on system, we should
stake out a reduc!on in the number of specimens maintained (biomass) and / or in the quan!!es of supplied food and see if the tank is stabilized at lower energe!c levels.
3
All rights reserved:
©José María Cid 2014
Few measures are more effec"ve in the control of "biological
pollu"on" of the aquarium, as a maintenance protocol that includes frequent par"al renewals of water. In marine aquariums
is recommended renewals of wáter between 15 and 20%
weekly, which in the case of freshwater aquariums can be between 30 and 50%, depending on the level of biomass maintained.
ers two or
If you have no inten"on of cleaning mechanical filters
three "mes a week, do not put . The opposite is just accumulate
organic detritus in an area of high flow off well oxygenated water and thus enhance the nitrifica"on
on at maximum level. The
same basic argument, serves to recommend make the greatest
possible effort in acquiring
ing the best "skimmer" and the best an"an"
an
"phosphates resines..
Management
ligh"ng,
nt of the pest through the ligh"ng
ng, if it
ng
it is o
off cyanocyan
cy
anoan
obacteria,
useful
species
ia, a us
usef
eful
ef
ul thought is remember that
ttha
hatt "invasive"
ha
"inv
"i
nvas
nv
asiv
as
ive"
iv
e" sspe
peci
pe
cies
ci
es is
not a plant
plan
antt and
an
and that
that it
it may even prefer coloniza"on
colo
co
loni
lo
niza
ni
za"o
za
"on
"o
n zones
zone
zo
nes that
ne
are not the mo
most
st intensely
iint
nten
nt
ense
en
sely
se
ly lit. However,
Howe
weve
ver, it is demonstrated
dem
d
emon
em
onstrated its
on
region
affinity for the
he orange-red
ora
rang
ra
ngee-re
ng
red
re
d re
regi
gion of thee spectrum, ie the longer
gi
wavelengths
velengths of the
the visible
vvis
isib
is
ible
ib
le spectrum.
sspe
pect
pe
ctru
ct
rum. This
ru
Th should lead us to take
two decisions:
decision
ons: First,
Firs
rst, we
rs
w should
shou
sh
ould
ou
ld use
u lamps
lam
amps
am
ps which radiated energy
ed more
m
towa
ward
wa
rdss the
rd
the "blue"
"blu
"b
lue"
lu
e" spectrum
sspe
pectru
pe
rum
ru
m (λ
(λ between 450
is focused
towards
and 300 nm),
nm), which would
w ld match
mat
atch
at
ch lamps
llam
amps characterised
am
ccha
hara
ha
racteris
ised
is
ed by an coures
ur
es of 800
000 to 1
00
100
0000
00
00 K ffor
or marine aq
aqua
uari
ua
riums. In
ri
lor temperatures
8000
10000
aquariums.
freshwater aquariums,
6000 K. Seconariums, no
not opt
op for lamps
la s below
be
Seco
dly, not delay in excess the
he replacement
rep
eplaceme
ep
ment
me
nt of the
th lamps with
wi new
ones, given that in some technologies
techno
te
nologies (fluorescent
no
(flu
fluorescent especially),
flu
ts radiated
radia
iated
ia
d spectrum shi*s towards the
the old lamps show its
"red".
Cyanobacteria, li•le-known
own but
bu common in aquarium
In all types
elimina"on of the colonies, whenever
es of
of pests,
pest
pe
sts,
st
s, a good
ggoo
ood
oo
d op"on is always the physical
ph
kee
eep
p in m
min
ind
in
d that
that "remove" isn't the same than " to move". We must catch and remove quiwe keep
mind
ckly outsi
outside
side
de the
the aquarium, great por"ons
por"o of invasive tapestry. We must therefore, not simply
cir
shake it and transport it to the circula"ng
water column, because in this case we only make that
empowerment the capability of the “pest” for invading new areas of the aquarium
in
In the case of an invasion
of pelagic algae (dinoflagellates), where the dras"c reduc"on of nitraphosph
tes and phosphates,
as already referred, does not resolve the problem, the use of UV-C lamps
and ozonators
ozon
are preferable op"ons.
In the case of benthic algae, most algaecides are using as ac"ve principles, copper or potassium
permanganate.
The use of an"bio"cs in the case of cyanobacteria, is known that it can be effec"ve (due to its
condi"on of gram-nega"ve bacteria), but carries the danger that a dose not enough high, could
lead to develop an strain resistant to the an"bio"cs used. On the other hand, have to take into
account, that the recommendable an"bio"cs are broad-spectrum and therefore also eliminated
the nitrifying bacteria beds (Nitrosomonas and Nitrobacter) in our aquarium.
4
All rights reserved:
©José María Cid 2014
Erythromycin and Tetracycline are the most frequently used
an!bio!cs in these cases. It is obtained good results by providing a single dose of 200mg /40l and proceed two days post to
change at least 50% of the aquarium water. Others alterna!ve
treatments described in the literature using hydrogen peroxide
(3%) at a dose of 40g / 50l.
Works cited
Welsh,DT (1994), “Microbial
obial Mats: structure, development..”,
developme
NATO Series G,E. Sciences VOl 35
Nielsen LP et al (1994),
1994), “Denitrifica#on, nitrifica#on, and nitrogen assimila#on in photosynthe#c microbial mats”, LJP Caume"e (eds)
mble S. (2002), “Algae Curse: a new view”, F.A.M.A
F.A.M
.M.A
.M
.A magazine
mag
m
agaz
ag
azin
az
in 2002-07
Gamble
In general it’s observed that cyanobacteria have a behavior in
the aquarium, which could be described as a "vital hysteresis"
sis"
in rela!on to the source of energy (food) that made them appear, in the sense that a once well established, even if the
liminated almost
"s!mulus" disappears (the food source is eliminated
completely ), they will remain alive and
nd even their colony may
grow. Against this background somewhat disturbing a final
conclusion seems we are able to extract: in terms of cyanobacteria, "be$er safe than
n so
sorry".©
For more informa•on
orma•on or to contact
cont
co
ntac
nt
actt the
ac
the author
auth
au
thor
th
or : www.aqua•cnotes.com
www.aqua•
a•cnotes
a•
es.c
es
.com
.c
om
Notes:
Note1: Oxygenic photosynthesis
hotosynthe
hesis is the
t most
mos
m
ostt widespread
os
wide
wi
desp
de
spre
sp
read type
re
typ
ypee of photosyntyp
modal
ality water
wate
terr acts
te
ts as the
the primary
primar
pr
aryy el
ar
electron
on d
don
onor,
hesis in nature. In this modality
donor,
here
re are other p
photo
tosynt
to
nthe
nt
he!c
he
!c organisms
organis
o
isms
is
ms among
a
releasing oxygen (O2). There
photosynthe!c
bu develop
p other
othe
her types
he
type
ty
pess of photosynthesis,
pe
pho
p
hotosynthe
ho
hesi
he
sis,
si
s, in
bacteria and archaebacteria but
which the electron donor compound
inspoun
und
d could
coul
co
uld
ul
d be an
a sulfide
sulfi
lfide
lfi
de or hydrogen
hy
tead of water.
Note2: Some authors (Stock & Ward,
rd, 1989) found
fo d that bacteria
bacte
teri
te
riaa are
ri
ar really
the first se"lers of the substrate followed
owed rapidly
rap
apid
ap
idly by
id
by the appearance of a
mono-layer of diatoms. Coloniza#on culminates
lminates
es with
wit
ith
it
h the appearance
appearan of
filamentous green algae a"ached to the framework
bacteria, cyanobacamew
ewor
ew
orkk of bacte
teria and diatoms.
Cyanobacteria, li•le-known but common in aquarium
5
All rights reserved:
©José María Cid 2014