Ochrobactrum ciceri sp. nov., isolated from nodules of Cicer arietinum

A Gram-staining-negative, aerobic, rod-shaped, non-spore-forming bacterial strain, Ca-34(T), was isolated from nodules of chickpea (Cicer arietinum) in Pakistan and studied for its taxonomic affiliation. The almost full-length 16S rRNA gene sequence showed highest similarities to those of strains of the genus Ochrobactrum. Based on results of MALDI-TOF MS and 16S rRNA gene sequence similarity (98.6 %), strain Ca-34(T) and Ochrobactrum intermedium LMG 3301(T) are phylogenetic neighbours; the two strains shared DNA-DNA relatedness of 64 %. The fatty acid profile [predominantly C(18 : 1)omega7c (67.7 %) and C(19 : 0) cyclo omega8c (19.6 %)] also supported the genus affiliation. Metabolically, strain Ca-34(T) differed from other type strains of Ochrobactrum in many reactions and from all type strains in testing positive for gelatin hydrolysis and in testing negative for assimilation of alaninamide and l-threonine. Based on phenotypic and genotypic data, we conclude that strain Ca-34(T) represents a novel species, for which we propose the name Ochrobactrum ciceri sp. nov. (type strain Ca-34(T) =DSM 22292(T) =CCUG 57879(T)).

Salana multivorans gen. nov., sp. nov., a novel actinobacterium isolated from an anaerobic bioreactor and capable of selenate reduction

Three facultatively anaerobic, Gram-positive bacteria, strains Se-3111T, Se-13111 and Se-1311A, were isolated from an anaerobic, dechlorinating bioreactor culture enriched from sediment of the River Saale in Germany. All strains were isolated from the dechlorinating mixed culture through their ability to reduce selenate anaerobically to elemental selenium. All three strains shared identical 16S rDNA sequences and phylogenetic analysis revealed that strain Se-3111T forms a novel taxon within the suborder Micrococcineae of the class Actinobacteria, related most closely to Beutenbergia cavernae. On the basis of genotypic, chemotaxonomic and physiological characteristics, it is proposed that the novel strains Se-3111T, Se-13111 and Se-1311A be classified in a new genus as Salana multivorans gen. nov., sp. nov. The type strain of the novel species is Se-3111T (= DSM 13521T = NRRL B-24118T).

Sulfitobacter mediterraneus sp. nov., a new sulfite-oxidizing member of the alpha-Proteobacteria

Analysis of PCR products of 16S rDNA of 680 isolates from Mediterranean Sea mesocosm experiments with taxon-specific 16S rDNA oligonucleotides revealed that 262 isolates belonged to the alpha subclass of the class Proteobacteria. Partial 16S rDNA sequence analysis of selected isolates and oligonucleotide probing with a Sulfitobacter-specific 16S rDNA probe affiliated 33 strains to the genus Sulfitobacter. Analysis of the HaeIII digest pattern of 16S rDNA revealed the presence of two groups; while 30 strains showed a pattern identical with that obtained for Sulfitobacter pontiacus DSM 10014T, a second group of three strains had a unique pattern that was different from that of the type strain. Five isolates of group 1 and one isolates of group 2, strain CH-B427T, were selected for detailed taxonomic analysis. All six isolates closely resembled the type strain Sulfitobacter pontiacus DSM 10014T in physiological reactions. However, strain CH-B427T differed quantitatively in the composition of fatty acids from Sulfitobacter pontiacus DSM 10014T and showed only 98.2% 16S rDNA sequence similarity with strain DSM 10014T. DNA-DNA reassociation value obtained for strains DSM 10014T and CH-B427T revealed 46% similarity. Based on the results of DNA-DNA reassociation and discrete differences in the nucleotide composition of 16S rDNA, a new species of the genus Sulfitobacter is proposed, designated Sulfitobacter mediterraneus sp. nov., the type strain being strain CH-B427T (= DSM 12244T).

Bacillus silvestris sp. nov., a new member of the genus Bacillus that contains lysine in its cell wall

A Gram-positive, aerobic, rod-shaped, peritrichously flagellated, round-endospore-forming bacterium was isolated from a forest soil near Braunschweig, Lower Saxony, Germany, and designated strain HR3-23T (T = type strain). Morphologically, strain HR3-23T shows the characteristics of a member of the genus Bacillus. The spore position is terminal in a swollen sporangium. Comparative analysis of the 16S rDNA sequence shows strain HR3-23T to be most closely related to Caryophanon tenue (95.8% 16S rRNA similarity) and to Bacillus sphaericus (95.4% 16S rRNA similarity). Phylogenetically, the isolate clusters among species of Bacillus RNA group 2. The DNA G + C content of isolate HR3-23T is 39.3 mol%, the peptidoglycan type is A4 alpha (L-Lys-D-Glu), the major respiratory lipoquinone is menaquinone MK-7 and the predominant fatty acid is of the iso-C15:0 type. Based on the morphological, chemotaxonomic, physiological and phylogenetic properties, a new species, Bacillus silvestris, is proposed; strain HR3-23T is the type strain (= DSM 12223T).

Influence of dithiocarb, (+)-catechin and silybine on halothane hepatotoxicity in the hypoxic rat model

In phenobarbital (phenemalum NFN)-pretreated male rats exposed to 1% halothane for 2 hrs under hypoxic conditions (10% O2), significant increases in serum enzyme activities of alanine aminotransferase and sorbitol dehydrogenase were observed 24 and 48 hrs later indicating liver damage. In this known model of halothane hepatotoxicity, pretreatment with (+)-catechin (200 mg/kg orally) or silybine (150 mg/kg orally) protected against halothane-induced liver injury, whereas diethyldithiocarbamate (200 mg/kg orally) failed to be effective. Halothane decreased the concentration of reduced glutathione in liver only under hypoxic conditions indicating that glutathione might be involved in the non-oxidative metabolic pathways of halothane. Free fluoride in plasma was used as a measure of non-oxidative defluorination of halothane. Higher plasma fluoride levels were observed under conditions which led to hepatotoxicity but did not correlate with the protective effects of the antidotes. This further supports the assumption that 2-chloro-1,1,1-trifluoroethane might be the radical intermediate responsible for halothane hepatotoxicity.

Halothane hepatotoxicity in hyperthyroid rats as compared to the phenobarbital-hypoxia model

Halothane hepatotoxicity was observed after exposing hyperthyroid rats to 0.625% halothane for 4 hr under hypoxic conditions (10% O2). In this model, increases in serum enzyme activities of the alanine aminotransferase (GPT) and the sorbitol dehydrogenase (SDH) were evident immediately following exposure and were six-fold higher than in the phenobarbital-hypoxic model. Plasma free-fluoride levels estimated immediately after exposure to halothane were increased twofold in halothane-exposed hyperthyroid rats under hypoxic conditions as were increased twofold in halothane-exposed hyperthyroid rats under hypoxic conditions as compared to a sixfold increase in the phenobarbital-hypoxic model. The concentration of glutathione in liver was more markedly decreased in hyperthyroid rats than in phenobarbital-induced rats. The fact that no clear-cut correlation was found between defluorination and hepatotoxicity in both models may favor the hypothesis that a non-defluorinated metabolite of halothane, e.g., 2-chloro-1,1,1-trifluoroethyl radical, is the reactive intermediate responsible for the liver lesions. On the other hand, intracellular hypoxia due to hypermetabolism during the hyperthyroid state may be the reason for the higher sensitivity of hyperthyroid rats.