TITLE:
Seasonal Shifts in the Bacterioplankton Assemblages of High Altitude Middle Atlas Lakes
AUTHORS:
Jaouad Anissi, Khalid Sendide, Ola A. Olapade
KEYWORDS:
Bacterial Diversity; High Altitude Lakes; Seasonal Shifts
JOURNAL NAME:
Journal of Water Resource and Protection,
Vol.6 No.1,
January
15,
2014
ABSTRACT:
Compositional changes of the bacterioplankton
assemblages in four high altitude middle Atlas lakes were monitored over a
complete seasonal cycle using combinations of culture-dependent and molecular
approaches. Viable bacterial numbers varied between seasons, with the lowest
numbers recorded in the winter and the highest in the summer in all four lakes.
Also, bacterial occurrences were found to be strongly correlated with water
temperature in all the four sites, i.e.,
Lake Aoua (0.88), Ifreh (0.59), Hechlef (0.77) and Affourgagh (0.79) during the
study period. Standard microbiological characterization of bacteria isolates
from the lakes revealed majority (68%) to be Gram positive. Seasonal variations in the microbial
assemblages among the lakes were also validated by restriction fragment length
polymorphism (RFLP). Shifts in microbial assemblages, especially of the fecal
indicator bacteria appeared to also be influenced by differences in the morphometric
and watershed characteristics among the lakes. This study further reveals the need to employ combinations of
methodological approaches, including taxonomic, physiological and molecular
methods to adequately delineate and fully understand the ecology of microbial
assemblages in extreme environments.