Molecular phylogeny and taxonomy of four Remanella species (Protozoa, Ciliophora): A flagship genus of karyorelictean ciliates, with descriptions of two new species.

During faunal studies of psammophilic ciliates along the coast of Qingdao, China, several marine karyorelictean species were isolated. Among them, four species within the genus Remanella were investigated, including two species new to science: i.e., R. rugosa, Remanella elongata sp. nov., Remanella aposinica sp. nov., and R. unicorpusculata. Remanella rugosa has been reported several times, but this study is the first to provide detailed morphological characters and phylogenetics. Remanella elongata sp. nov. can be distinguished from its congeners by the presence of complex cortical granules, fewer macronuclei, and longer body size. Remanella aposinica sp. nov. differs from its congeners by having 14-17 right lateral ciliary rows and 24-37 dikinetids of intrabuccal kinety. Poorly known Remanella rugosa var. unicorpusculata (Kahl, 1933) Foissner, 1996 should be elevated from subspecies to species level, Remanella unicorpusculata (Foissner, 1996) stat. nov., based on detailed redescriptions with statistical data, living morphology, infraciliature, and species definitions. Small subunit (SSU) rDNA was sequenced for the four species, and phylogenetic analysis revealed that all known taxa in Remanella formed the outline branch to the genus Loxodes with moderate to high bootstrap support among Remanella lineages.

[Monoclonal antibodies prepared and used for detection of acute virus necrobiotic disease virus in scallop Chlamys farreri by indirect ELISA].

For developing monoclonal antibodies against acute virus necrobiotic disease (AVND) virus, mice of Balb/c strain were immunized with AVND virions which were isolated from the infected scallop Chlamys farreri. The spleen cells from immunized mice were then fused with NS-1 myeloma cells and the hybridomas were screened by means of enzyme-linked immunosorbent assay (ELISA) and immunofluorescence assay (IFA). Finally, 4 stable MAbs of IgG isotype were obtained. Moreover, the combined position of these 4 MAbs to this virus was examined by immunogold electron microscopy (IEM). The results demonstrate that all 4 MAbs recognized epitopes on the envelope of the virions. Subsequently, a MAb-based ELISA was developed and used for detection of the infection rate and densities of the scallops which were sampled during different seasons from mid-April to mid-October, 2003. The result exhibited that both of the infection rate and infection densities sharply rose in mid-July and reached to the spikes, which right corresponds with their mortality during this period.

[Histopathological research and immunofluorescence of AVND virus infection in cultured scallop Chlamys farreri].

The naturally infected scallops Chlamys farreri sampled during mass mortality in summer of 2003 was detected by means of histopathological and MAb-based immunofluorescence assay (IFA). The results of histological examination demonstrated that a series of histopathological changes including cell swelling, basophilic increase, disorder, partial sloughing and excessive sloughing were always observed in epithelia of many different organs, e.g. mantle, gills, stomach, intestine and kidney. Additionally, the infected tissues were applied for in situ detection of the "acute virus necrobiotic disease" (AVND) virus by means of specific MAb-based IFA, and the result demonstrated that this pathological changes or lesions were perfectly coincident with the positive cells (fluorescencing cells) . The positive cells were denser in some local area of epithelia, and exhibited serious pathological lesions, which would reveal the roles of this virus in pathogenesis and further confirm that the AVND virus is the main causative agent of mass mortalities among cultured scallop Chlamys farreri farmed in northern coast of China.

Direct conversion of inulin and extract of tubers of Jerusalem artichoke into single cell oil by co-cultures of Rhodotorula mucilaginosa TJY15a and immobilized inulinase-producing yeast cells.

In this study, it was found that the immobilized inulinase-producing cells of Pichia guilliermondii M-30 could produce 169.3 U/ml of inulinase activity while the free cells of the same yeast strain only produced 124.3 U/ml of inulinase activity within 48 h. When the immobilized inulinase-producing yeast cells were co-cultivated with the free cells of Rhodotorula mucilaginosa TJY15a, R. mucilaginosa TJY15a could accumulate 53.2% oil from inulin in its cells and cell dry weight reached 12.2g/l. Under the similar conditions, R. mucilaginosa TJY15a could accumulate 55.4% (w/w) oil from the extract of Jerusalem artichoke tubers in its cells and cell dry weight reached 12.8 g/l within 48 h. When the co-cultures were grown in 2l fermentor, R. mucilaginosa TJY15a could accumulate 56.6% (w/w) oil from the extract of Jerusalem artichoke tubers in its cells and cell dry weight reached 19.6g/l within 48 h. Over 90.0% of the fatty acids from the yeast strain TJY15a grown in the extract of Jerusalem artichoke tubers was C(16:0), C(18:1) and C(18:2), especially C(18:1) (50.6%).