Rhizobium lacunae sp. nov., Isolated From a Freshwater Pond

Bacterial strain designated CSW-27T was isolated from a freshwater pond in Taiwan. Cells were Gram-stain-negative, aerobic, oxidase-positive, catalase-negative, rod-shaped and motile by flagella. Strain CSW-27T grew at 20-40 oC (optimum, 30-37 oC), at pH 5-9 (optimum, pH 6-7) and in the presence of 0-4% NaCl (optimum, 0%). Phylogenetic analyses based on 16S rRNA gene sequences and an up-to-date bacterial core gene set revealed that strain CSW-27T was affiliated with species in the genus Rhizobium. Analysis of 16S rRNA gene sequences showed that strain CSW-27T had the highest similarity to Rhizobium straminoryzae CC-LY845T (98.5%) followed by Rhizobium capsici CC-SKC2T (96.9%). The average nucleotide identity, average amino acid identity and digital DNA-DNA hybridization values between strain CSW-27T and the closely related Rhizobium species were 73.4-86.5, 66.0-88.8 and 13.3-22.1%, respectively. The principal fatty acid was summed feature 8 (C18:1ω7c and/or C18:1ω6c). The main polar lipids were phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidylmonomethylethanolamine, phosphatidyldimethylethanolamine, phosphatidylcholine, one uncharacterized aminophospholipid, three uncharacterized aminolipids and two uncharacterized lipids. The predominant polyamine was spermidine. The major isoprenoid quinone was Q-10. Genomic DNA G+C content of strain CSW-27T was 63.3%. These polyphasic taxonomic data indicited that strain CSW-27T should be considered as representing a novel species in the genus Rhizobium, for which the name Rhizobium lacunae sp. nov. is proposed with strain CSW-27T (=BCRC 81244T =LMG 31684T) as the type strain.

Paracoccus xiamenensis sp. nov., isolated from seawater on the Xiamen

Strain 12-3T was isolated from seawater of the Guanyinshan Coast, Xiamen, Fujian Province, PR China. The bacterium was Gram-stain-negative, rod-shaped, aerobic, oxidase-positive and catalase-negative. Growth of strain 12-3T occurred at 10–37 °C (optimum, 20–30 °C), at pH 5.0–11.0 (optimum, pH 7.0–8.0) and at a salinity range of 0–10 % (optimum, 3–5 %). The results of phylogenetic analysis based on its 16S rRNA gene sequence indicated that strain 12-3T belonged to the genus Paracoccus and had the highest sequence similarity to Paracoccus lutimaris HDM-25T (97.4 %), followed by Paracoccus isoporae SW-3T (96.9 %), Paracoccus caeni MJ17T (96.9 %), Paracoccus pacificus F14T (96.8 %) and other species in the genus Paracoccus (95.3–96.5 %). The average nucleotide identity (ANI) and DNA–DNA hybridization (DDH) values between strain 12-3T and P. lutimaris HDM-25T were 76.1 and 17.0 %, respectively. ANI and DDH values between strain 12-3T and P. isoporae SW-3T were 78.9 and 18.2 %, respectively. The principal fatty acid of strain 12-3T was summed feature 8 (C18 : 1 ω6c/ω7c) and C18 : 0. The respiratory quinone of strain 12-3T was Q10. The polar lipids included phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol and an unidentified glycolipid. The G+C content of the chromosomal DNA was 63.9 mol%. The combination of the results of the phylogenetic, phenotypic and chemotaxonomic analyses, and its low ANI and DDH values indicate that strain 12-3T represents a novel species of the genus Paracoccus , for which the name Paracoccus xiamenensis sp. nov. is proposed. The type strain is 12-3T (=MCCC 1A16381T=KCTC 72687T).

Chemical Characterization of the Lipophilic Fraction of Livistona Decipiens and Livistona Chinensis Fruit Pulps (Palmae) and Assessment of Their Anti-hyperlipidemic and Anti-ulcer Activities

The oil of the dried pulps of Livistona decipiens and L. chinensis palm fruits have been studied for the first time by gas chromatography-mass spectrometry for their unsaponifiable matter (USM) and fatty acid composition (FAME). The anti-hyperlipidemic and anti-ulcer activities for both oils were also assayed. The principal fatty acid of L. decipiens pulp oil was oleic acid (53.4 %) and of L. chinensis pulp oil palmitic acid (47.4 %). In relation to anti-hyperlipidemic properties, the pulp oil of L. decipiens presented a better profile than that of L. chinensis, in comparison with the reference standard (simvastatin). In addition, both pulp oils showed high anti-ulcer activity using an indomethacin-induced ulceration technique in rat stomach. The relationship between the anti-hyperlipidemic, anti-ulcer and chemical composition of the pulp oils is also discussed.

Roseovarius crassostreae sp. nov., a member of the Roseobacter clade and the apparent cause of juvenile oyster disease (JOD) in cultured Eastern oysters

An α-proteobacterium has been identified which is believed to be the causative agent of juvenile oyster disease (JOD). Since its first isolation in 1997, the bacterium has been recovered as the numerically dominant species from JOD-affected animals throughout the north-eastern United States (Maine, New York and Massachusetts). Colonies are usually beige to pinkish-beige, although the majority of isolates recovered in 2003 from an epizootic in Martha's Vineyard, Massachusetts, produce colonies with a greenish-yellow appearance. The cells are Gram-negative, aerobic, strictly marine and rod or ovoid in appearance. They are actively motile by one or two flagella, but cells are also observed to produce tufts of polar fimbriae. The principal fatty acid in whole cells is C18 : 1 ω7c and other characteristic fatty acids are C16 : 0, C10 : 0 3-OH, 11-methyl C18 : 1 ω7c and C18 : 0. Almost without exception, isolates have 16S rRNA gene sequences that are 100 % identical to each other. Phylogenetic analyses place the organism within the Roseobacter clade of the α-Proteobacteria, with moderate bootstrap support for inclusion in the genus Roseovarius. DNA–DNA relatedness values from pairwise comparisons of this organism with the type species of the genus (Roseovarius tolerans) and the only other described species in this genus, Roseovarius nubinhibens, were 11 and 47 %, respectively. Phenotypic and biochemical dissimilarities also support the assignment of this bacterium to a novel species. The name Roseovarius crassostreae sp. nov. is proposed, with the type strain CV919-312T (=ATCC BAA-1102T=DSM 16950T).

Fatty acid release in incubations of serum with synaptosome and myelin subfractions of brain

To study lipid breakdown in brain membranes following hemorrhage, synaptosome and myelin fractions isolated from rat brain were incubated with rat serum. After 3 h in vitro at 37 °C, 0.43 and 0.26 μmol of fatty acid were released in incubations containing synaptosomes (1.37 μmol phospholipid) or myelin (1.23 μmol phospholipid), respectively, in the presence of 0.25 mL serum. Less than 0.05 μmol of fatty acid was liberated in incubations containing only serum, synaptosomes, or myelin. For synaptosomes and serum, docosahexaenoate was the principal fatty acid released (28 mol% of total) after 3 h of incubation. This fatty acid and arachidonate made up 43 mol% of the liberated fatty acid. The presence of free docosahexaenoate was of interest, as this fatty acid is particularly enriched in phosphatidylserine and phosphatidylethanolamine, phospholipids found in the cytoplasmic half of the synaptosomal plasma membrane and in interior synaptosomal membranes. In incubations of serum and myelin, oleate was the major free fatty acid produced in 30 min to 3 h of incubation (29–35 mol% of total). After 3 h, docosahexaenoate contributed 20 mol% to the total. The release of fatty acids from the membranes may be mediated by serum phospholipase(s) or possibly by activated endogenous lipolytic activities.Key words: fatty acid, serum, synaptosome, myelin, phospholipase A2.

Characterization of pulmonary surfactant from ox, rabbit, rat and sheep

1. Pulmonary surfactants from ox, rabbit, rat and sheep were isolated and analysed. 2. All preparations had a high anenoic phosphatidylcholine content and would produce stable surface tensions of 0.01 Nm−1 or less. 3. Protein content was 8-18% of the dry weights. A number of proteins were observed; their overall composition were high in hydrophobic amino acid residues. 4. Lipid content varied from 79% (ox) to 90% (rabbit) with phosphatidylcholine representing from 58% (sheep) to 83% (rabbit) of the total lipid. The surfactant preparations were rather similar in lipid composition except that sheep surfactant contained about 10% lysophosphatidylcholine. 5. Hexadecanoic acid was the principal fatty acid. It was particularly high in phosphatidylcholine. 6. Phosphatidylglycerol was a minor constituent of all surfactants but phosphatidyldimethylethanolamine was not detected.

Metabolism of fatty acids by bovine spermatozoa

The incorporation of 14C-labelled myristic, palmitic, stearic, oleic and linoleic acids in vitro into the lipids of bovine spermatozoa was measured at intervals from 2min to 2h. All acids were rapidly incorporated into diglycerides, myristic acid being metabolized to the greatest extent. Whereas the low incorporation of acids into total phospholipids reflected the relative stability of the major phospholipid fractions in sperm, the minor phospholipids, particularly phosphatidylinositol, showed comparatively high metabolic activity. Although, in general, saturated acids were incorporated more actively than unsaturated substrates, stearic acid was poorly incorporated into all lipids except phosphatidylinositol. In regard to fatty acid composition of sperm lipids it was notable that diglycerides contained myristic acid as the major component, and this acid was also a prominent moiety of phosphatidylinositol. Docosahexaenoic acid was the principal fatty acid of the major phospholipid classes. These findings have been discussed in relation to the role of lipids in the metabolism of spermatozoa.

THE LIPIDS OF LIPOMYCES LIPOFER

As a preliminary to the study of lipid synthesis in Lipomyces lipofer, the nature of the lipid accumulated by this organism was investigated. Neutral lipids were found to predominate, especially in older cultures of high lipid content. The triglyceride fraction was the major component, with smaller quantities of hydrocarbon, free and esterified ergosterol, monoglyceride, diglyceride, and free fatty acid also present. Phosphatid-y-linositol constituted almost one-quarter of the phospholipid fraction. The phosphoglycerides of choline, serine and ethanolamine were also detected. Gas chromatographic evidence indicated that 16:0, 16:1, 18:0, 18:1, 18:2, 18:3 were the principal fatty acid components. The 18:1 fraction was shown by oxidative-cleavage studies to be primarily oleic acid. This fraction predominated, reaching a level of 69% of the total fatty acids in older cultures.