Annual Fluctuations of Phytoplankton and Bacterial Communities in Maizuru Bay and their Interrelationship

Abstract

The annual changes in bacterial community were studied as related to those of phytoplankton in Maizuru Bay, Japan from May 1985 to April 1986 Five phytoplankton blooms were observed through the year Dominant algal species for three blooms were diatoms, Cerataulina pelagica, Asterionella japonica and Leptocylindrus danicus, and for the other two, dinoflagellate Prorocentrum micans and Raphidophycean Chattonella marina, respectively. The analysis of the bacterial community revealed that in these blooming periods the diversity of bacterial flora decreased. In particular the bacteria of genus Vibrio were not found in the bloom of phytoplankton A positive correlation was found between abundance of free-living bacteria and chlorophyll a concentrations. The results suggest that phytoplankton in the blooming period influences the bacterial flora and the bacterial concentration is closely related to the abundance of phytoplankton.

Stimulative and inhibitory effects of bacteria on the growth of microalgae

“…Riquelme et al (1987) investigated bacterial community structure before and after some algal blooms and observed that high densities of the Pseudomonas sp. 022 developed just before the alga Asterionella glacialis (= japonica) bloomed.…”

The contribution of bacteria to algal growth by carbon cycling

“…It is generally thought that the algae and bacteria maintain symbiotic relations. Previous work has shown that the presence of bacteria may aid algal productivity (Andersen, ; Fukami et al, ; Riquelme et al, ; Suminto and Hirayama ). The stimulative effect of bacteria on algal growth has been described as being associated with bacteria mineralizing carbon (Ask et al, ; Muñoz and Guieysse, ), as well as cycling nutrients (Bloesch et al, ; Zhao et al, ) and generating vitamins (Grant et al, ) and other growth promoting regulators.…”

Simultaneous Growth of <i>Chaetoceros muelleri</i> and Bacteria in Batch Cultures

“…This indicates that the cells in exponential growth produced less exudates and detritus than those cultured at 18-L and 400-L. On the other hand, secondary metabolites such as amino acids, carbohydrates, and vitamins required for bacterial growth are generally produced during the stationary phase. The highest density of bacterioplankton occurs after the maximum production of phytoplankton [16] [17], and under in vitro conditions the maximum abundance of bacteria occurs after the maximum production of chlorophyll a [18]. Our results therefore indicate that as the culture volume increases, the abundance of bacteria increases; hence, bacteria can be introduced into systems used for aquaculture production of crustacean and mollusc larvae when C. muelleri is used as food.…”