Biomedical subjects

Adriana Giangrande

Publications and source records attributed to Adriana Giangrande.

6 recordsLinked to original sources

PubMed2006

Bacterial accumulation by Branchiomma luctuosum (Annelida: Polychaeta): a tool for biomonitoring marine systems and restoring polluted waters.

In this study, we examined the bacterial accumulation in the filter feeder polychaete Branchiomma luctuosumGrube (Sabellidae). Analyses were performed on worm homogenates from 'unstarved' and 'starved' individuals, and seawater from the same sampling site (Gulf of Taranto, Western Mediterranean, Italy). Densities of culturable heterotrophic bacteria (22 degrees C), total culturable bacteria at 37 degrees C and halophilic vibrios at 22 and 35 degrees C were measured on Marine Agar 2216, Plate Count Agar and thiosulphate-citrate-bile-salt-agar (TCBS) plus 2% NaCl, respectively. Total and faecal coliforms as well as faecal streptococci were determined by the Most Probable Number method. Results showed that B. luctuosum is able to accumulate all the considered six microbiological groups with a higher efficiency for autochthonous bacteria. The analysis also indicated that bacterial groups differ in their resistance to digestion by B. luctuosum. Our data suggest the potential role of B. luctuosum as an useful bioindicator to assess low levels of microbiological water pollution as well as bioremediator of microbial polluted waters.

Animals↗

PubMed2006

Filtering activity of Spongia officinalis var. adriatica (Schmidt) (Porifera, Demospongiae) on bacterioplankton: implications for bioremediation of polluted seawater.

A study on the filtering activity has been carried out on reared specimens of the demosponge Spongia officinalis var. adriatica coming from an off-shore farm displaced off the Apulian coast (Ionian Sea). The experience was carried out under laboratory conditions, by using natural seawater collected from the sponge environment. The study demonstrates a high efficiency of the sponge in removing bacteria. Bacterial concentration significantly decreases in presence of the sponge, with a marked drop after 2 h from the start of the experience. The maximum clearance rate was 210 ml h(-1) g(-1) DW at 60 min. Retention efficiency reached the highest value of 61% at 120 min. The bacterial density removed by the S. officinalis filtering activity was 12.3 +/- 1.8 x 10(4) cells ml(-1) corresponding to a biomass of about 11.7 +/- 1.4 microg Cl(-1). The sponge fed preferentially large- and medium-size bacteria, whereas the small ones are fed after the removal of the largest size categories. The results obtained suggest that S. offcinalis is a suitable species for marine environmental bioremediation.

Animals↗

PubMed2005

Sabella spallanzanii filter-feeding on bacterial community: ecological implications and applications.

The filtration process of Sabella spallanzanii Gmelin on bacterial community was studied in a coastal area of the Northern Ionian Sea (Mediterranean Sea) at three sites, S. Vito, Lido Gandoli and Lido Silvana, where some specimens of S. spallanzanii were transplanted. Analyses were performed both on water and worm samples. A total of six microbial groups were examined: culturable heterotrophic bacteria, total culturable bacteria at 37 degrees C, culturable vibrios, total and fecal coliforms and fecal streptococci. The bacterial densities were usually orders of magnitude higher in the worm homogenates than in the corresponding seawater and the highest values were observed in August. The ability of S. spallanzanii to accumulate the microbial pollution indicators suggests this species can be employed as a bioindicator for monitoring water quality. Moreover, the accumulation capability of S. spallanzanii for specific micro-organisms provides a potential role in sewage bioremediation.

Analysis of Variance↗

PubMed2005

Clearance rates of Sabella spallanzanii and Branchiomma luctuosum (Annelida: Polychaeta) on a pure culture of Vibrio alginolyticus.

The influence exerted by filter-feeding activity on bacterial density by two sabellid species from the Mediterranean Sea (Ionian Sea, Italy), Branchiomma luctuosum Grube and Sabella spallanzanii Gmelin (Annelida: Polychaeta) was investigated. Clearance rates and retention efficiencies were estimated utilizing the species Vibrio alginolyticus selected on account of previous field studies and its importance in fish culture pathogenicity. The Cmax was 43.2+/-2.63 L h(-1) g(-1) DW for B. luctuosum and 12.4+/-2.22 L h(-1) g(-1) DW for S. spallanzanii. The Retention efficiency was 98% corresponding to a removed bacterial biomass of 44.8+7.88 microgC L(-1) g(-1) DW for B. luctuosum and 70% corresponding to a bacterial biomass of 23.8+2.95 microgC L(-1) g(-1) DW for S. spallanzanii. Maximum retention was recorded after 20 min for the first species and after 30 min for the second one. Present laboratory experiments represent a contribution to the knowledge of the filtration activity of the two polychaetes, characterizing the filtration process on bacterioplankton. Both species resulted extremely efficient in removing V. alginolyticus from seawater in experimental tanks, thus confirming the previous data from the field studies and suggesting their employment as biofilters of microbially contaminated waters in intensive aquaculture.

Animals↗

PubMed2005

Polychaetes as environmental indicators revisited.

The utilization of polychaetes in descriptive ecology is reviewed in the light of recent research especially concerning the biota hard bottom environments. Polychaetes, often linked in the past to the concept of opportunistic species able to proliferate after an increase in organic matter, have played an important role especially with regard to impacted soft-bottom habitats. Increased knowledge of the group, suggests that not only opportunistic species can be utilised as indicators, so that these organisms can be disengaged from the old concept of opportunistic taxa. Moreover, recent researches conducted on this group allowed demonstrating as surrogacy is not always applicable. Among polychaetes inhabiting hard bottom environment, the analysis of family Syllidae appears particularly promising. Studied conducted in our laboratory demonstrated as syllid species decrease in abundance or completely disappear under varying sources of negative impact. The distribution of species also appeared indicative in underlying effects of marine protected areas (MPA) functioning, or in describing different climatic areas within biogeographical sectors. It is obvious that good results can only be obtained on the basis of good taxonomic resolution. We suggested that, in monitoring studies, operational time could be optimized not only by working at a higher-level on the whole invertebrate data set, but by also selecting a particularly indicative group and working at fine level.

Animals↗

PubMed2003

External gestation of Exogone naidina Oersted, 1845 (Polychaeta, Syllidae): ventral attachment of eggs and embryos.

The external gestation of sexually ripe females of the species Exogone naidina (Polychaeta, Syllidae) is described by means of SEM and TEM analysis. The eggs, embryos and juveniles are attached in close vicinity of each parapodial complex in a position immediately below each ventral cirrus and are connected to the female by a cup like structure. The formation of this adhesive disk is linked to secretory cells scattered between dermal cells of ripe female. This adhesive disk is present only in sexually mature animals and is considered as epitokous structure. The evolutive significance of ventral and dorsal attachment found within the Exogoninae is also discussed.

Animals↗