Microalgae
are
photosynthetic
microorganisms
which
can
grow
under
a
large
spectrum
of
conditions
and
may
produce
number
valuable
products.
However,
increased
chlorophyll
concentration
constitutes
limiting
factor,
especially
in
large-scale
photo-bioreactors,
causing
“shadow
effect”
negatively
influences
biomass
productivity.
The
main
scope
the
present
study
was
to
select
low
content
strain
Stichococcus
sp.,
order
increase
light
penetration
into
culture
photo-bioreactors.
Selection
through
random
mutation
using
ethyl
methanesulfonate
(EMS).
Two
promising
mutants
(EMS1
&
EMS2)
were
isolated
cultivated
for
three
generations
on
solid
medium
(petri
dishes).
selected
strains
then
open
beaker
glassware
with
200
mL
F/2
medium,
diluted
natural
seawater,
sterile
conditions.
EMS1,
best
performing
mutant
strain,
exhibited
lower
(43%),
higher
(12%),
lipids
(45%),
carbohydrates
(28%)
production,
compared
wild
type.
EMS1
proved
contain
least
(6.29
±
0.52
mg
g-1),
yet
highest
(2.47
0.10
g
L-1),
(21%
dry
biomass),
(44%
biomass)
type
strain.
Protein
did
not
differ
significantly
among
strains.
sp.
has
high
potential
further
investigation
production
various
bio-chemicals.
This
study
explored
the
effect
of
Copper
(Cu)
on
fermentative
hydrogen
production
from
sewage
sludge
(SS)
and
glucose.
Results
showed
that
stimulative
dosages
Cu
glucose
SS
were
20-60
mg/L
20-100
mg/L,
respectively.
The
stimulation
was
more
significant
to
(6.3-43.8%)
than
(4.8-16.1%).
500-1000
posed
obvious
inhibition
production,
(80.6-91.9%)
(25.0-37.5%),
which
due
protective
producers
adsorbing
Cu.
exposure
enriched
Cu-resistant
microorganisms
like
genus
Aeromonas,
Comamonas,
Pseudomonas
Dechloromonas.
Metabolic
analysis
shows
low
stimulated
by
strengthening
formate
decomposition
process,
weakening
lactate
formation
homoacetogenesis
processes,
while
high
inhibited
all
hydrogen-producing
processes
including
decomposition,
ferredoxin
hydrogenation
processes.
Microalgae
are
photosynthetic
microorganisms
which
can
grow
under
a
large
spectrum
of
conditions
and
may
produce
number
valuable
products.
However,
increased
chlorophyll
concentration
constitutes
limiting
factor,
especially
in
large-scale
photo-bioreactors,
causing
“shadow
effect”
negatively
influences
biomass
productivity.
The
main
scope
the
present
study
was
to
select
low
content
strain
Stichococcus
sp.,
order
increase
light
penetration
into
culture
photo-bioreactors.
Selection
through
random
mutation
using
ethyl
methanesulfonate
(EMS).
Two
promising
mutants
(EMS1
&
EMS2)
were
isolated
cultivated
for
three
generations
on
solid
medium
(petri
dishes).
selected
strains
then
open
beaker
glassware
with
200
mL
F/2
medium,
diluted
natural
seawater,
sterile
conditions.
EMS1,
best
performing
mutant
strain,
exhibited
lower
(43%),
higher
(12%),
lipids
(45%),
carbohydrates
(28%)
production,
compared
wild
type.
EMS1
proved
contain
least
(6.29
±
0.52
mg
g-1),
yet
highest
(2.47
0.10
g
L-1),
(21%
dry
biomass),
(44%
biomass)
type
strain.
Protein
did
not
differ
significantly
among
strains.
sp.
has
high
potential
further
investigation
production
various
bio-chemicals.
