Environmental Engineering Reference
In-Depth Information
Table 2.25
Marine yeasts
Subdivision
Family
Genus
a
Ascomycotina
Metschnikowiaceae
Metschnikowia
a
a
Saccharomycetaceae
Debaryomyces, Hanseniaspora, Hansenula, Klayveromyces
, Pichia
,
Saccharomyces
a
,
a
,
Basidiomycotina
Sporobolomycetaceae
Leucosporidium
Rhodosporidium
Sporobolomyces
a
, Cryptococcus
a
, Kloleckera, Rhodotorula
a
,
Deutermycotina
Torulopsidaceae
(yeast-like cells)
Candida
a
a
Sterigmatomyces
, Torulopsis
, Trichosporon, Aureobasidium/
Pullularia
a
Contains obligate marine species. After Kohlmeyer and Kohlmeyer (
1979
)
metabolic activity of marine micro-organisms
with a reduction of pressure (Jannach and Wirsen
1982
). This helps to draw an inference that the
activity of marine micro-organisms is more in the
shallow water and decreases with the increase of
depth and pressure.
Micro-organisms are also distributed in the
deep-sea sediments. Deming and Colwell (
1985
)
used epi
productive ecosystem for photosynthetic aerobes.
The range of saline concentrations creates three
types of niches: fresh water, brackish water and
saline water. Each niche is occupied by organisms
that are adapted for those conditions. This form of
ecological portioning reduces exploitative com-
petition and enhances growth of different types of
microbial communities (Campbell
1993
). Simi-
larly, the continental shelf and the coral reefs are
areas of high productivity due to high nutrients
and photon energy, but without
uroscence microscopy to determine the
vertical distribution of bacteria in deep-sea sedi-
ments. Thus, using core samples collected at
depths exceeding 4,000 m, it was recorded that
bacterial populations at the surface layer of sedi-
ment amounted to 4.65
fl
the extreme
salinity gradient (Atlas
1998
).
Conversely, the ocean zones are not as highly
productive except for the pleuston layer where
there is adequate light for microbes that are
dominant primary producers. The pelagic off-
shore zone does not have enough nutrients at the
surface to support signi
10
8
bacteria/gm dry
weight. However, there was a doubling in num-
bers to 8.29
×
10
8
bacteria/gm dry weight at a
sediment depth of 3 cm followed by progressively
decline to 1.7
×
10
7
bacteria gm dry weight in a
core sample at 15 cm from the surface of the
sediment. Parallel results were obtained in a sec-
ond core collected from a similar depth. Higher
counts of approximately 3.07
cant microbial growth.
The primary producers lyse and sink to the deep
benthic zone. The benthic zone, rich in nutrients,
does not have enough light energy to support
primary productivity. Other forms of energy deep
in the hadal trenches, combined with fresh
outpourings of chemical nutrients from the mol-
ten core, provide the congenial environmental
conditions for islands of deep undersea commu-
nities of rare bacteria and peculiar species
(National Geographic
1979
). The deep-sea vents
occur in the ocean
×
10
10
bacteria/gm
dry weight were recorded from faecal pellets.
These counts were 9-folds to 72-folds higher than
in the underlying surface sediment
×
(Deming
1985
).
An outline search performed by us on the
habitat of marine microbes (
http://www.geocites.
revealed the estuarine environment highly
favourable for the survival of diverse strains of
microbes. This is because the constantly changing
environmental parameters can create a wide
diversity of ecological niches in this brackish
water ecosystem (Atlas
1998
). Estuaries have high
nutrients and high photon energy and are the most
oor where the ocean crustal
plates spread apart and cause plumes of hot lava
to erupt into the ocean. The high concentrations
of electron-rich elemental compounds are very
congenial for the growth and survival of eubac-
teria such as the chemoautotrophs (Campbell
1993
). Each type of bacteria has special adapta-
tions
fl
that
enable
the organism to obtain
