Unraveling the ecological impacts of Phaeocystis globosa bloom: From plankton community succession.

Bloom-induced disturbances in marine ecosystems can cause an initial destabilization of plankton and the subsequent collapse of coastal ecosystems. However, our understanding of the impact of blooms on planktonic community structure remains limited. Here, we investigated the responses of plankton communities in the Beibu Gulf of the South China Sea following a Phaeocystis globosa bloom.

Ammonifying and phosphorus-solubilizing function of sp. nov. isolated from bloom and algal-bacterial interactions.

blooms are of escalating global concern due to their substantial ecological impacts on marine ecosystems. Emerging evidence indicates that algae-bacterial interactions play pivotal roles in shaping the ecology and evolution of harmful algal blooms, although much of this interplay remains unexplored. We successfully isolated and propagated two novel bacterial strains from bloom.

Detecting the Phaeocystis globosa bloom and characterizing its bloom condition in the northern Beibu Gulf using MODIS measurements.

Phaeocystis globosa is the most common species making up harmful algal blooms. For better detect P. globosa bloom, a multispectral approach was developed based on extensive in-situ investigation and MODIS remote sensing reflectance (R) dataset.

Effects of nutrient limitation on cell growth, exopolysaccharide secretion and TEP production of Phaeocystis globosa.

Phaeocystis globosa (P. globosa) often colonizes and produces mucus, which may cause massive blooms in coastal areas. To understand mechanism of the growth and the impact factors for better control of the bloom, we conducted a laboratory experiment on the effect of nitrogen (N) or phosphorus (P) limitation on the cell growth, production of exopolysaccharide (EPS), and transparent exopolymeric particles (TEP) of P.

New antioxidative secondary metabolites from the fruits of a Beibu Gulf mangrove, Avicennia marina.

Further chemical investigation of the fruits of the mangrove, Avicennia marina, afforded three new phenylethyl glycosides, marinoids J-L (1-3), and a new cinnamoyl glycoside, marinoid M (4). The structures of isolates were elucidated on the basis of extensive spectroscopic analysis and by comparison of the data with those of related secondary metabolites. The antioxidant activity of the isolates was evaluated using the cellular antioxidant assay (CAA), and compounds 1-4 showed antioxidant activities, with EC50 values ranging from 23.

Two new avermectin derivatives from the Beibu Gulf gorgonian Anthogorgia caerulea.

Two new avermectin derivatives, avermectins B1c and B1e (1 and 2, resp.), as well as two known compounds, avermectin B2a (3) and ivermectin A1a (4), were isolated from a Beibu Gulf gorgonian coral, Anthogorgia caerulea. The structures of the new compounds were established by detailed spectroscopic analysis and by comparison with spectral data of related known compounds.

Four new Jacaranone analogs from the fruits of a Beibu Gulf mangrove Avicennia marina.

Four new jacaranone analogs, marinoids F-I (1-4), were isolated from the fruits of a Beibu Gulf mangrove Avicennia marina. The structures were elucidated based on analysis of spectroscopic data. Marinoids F and G are shown to be diastereoisomers of chlorocornoside, a new halogen containing marine secondary metabolite.

[Annual change of phytoplankton ecological features in Fangchenggang Bay of Guangxi, South China].

In March, June, September, and December 2007, investigations were conducted on the species composition, dominant species, community structure, and abundance distribution of phytoplankton in the Fangchenggang Bay of Guangxi. Based on the investigation data, the phytoplankton abundance, biotic index, and their correlations with environmental factors were analyzed. A total of 138 species of 54 genera were identified, among which, 112 species belonged to 37 genera of diatoms, 21 species belonged to 12 genera of dinoflagellates, 2 species belonged to chrysophyta, 2 species belonged to chlorophyta, and 1 species belonged to cyanophyta.