Isolation and characterization of a new facultatively autotrophic hydrogen-oxidizing Betaproteobacterium, Hydrogenophaga sp. AH-24

A hydrogen-oxidizing bacterium strain AH-24 was isolated, which was classified in the genus Hydrogenophaga, based on the 16S rRNA gene sequence. The isolate possessed a typical yellow pigment of Hydrogenophaga species. Its closest relative was Hydrogenophaga pseudoflava, but the assimilation profile of sugar compounds resembled that of no species of Hydrogenophaga. The optimum temperature and pH for autotrophic growth were, respectively, 33-35 degrees C and 7.0. Most hydrogenase activity (benzyl viologen reducing activity) was localized in the membrane fraction (MF), but NAD(P)-reducing hydrogenase activity was detected in neither the membrane nor the soluble fractions. Cytochromes b561 and c551 were present in MF; both were reduced when hydrogen was supplied to the oxidized MF, suggesting involvement in respiratory H2 oxidation as electron carriers. Cytochrome b561 was inferred to function as the redox partner of the membrane-bound hydrogenase.     

Characterization of novel Alu- and tRNA-related SINEs from the tree shrew and evolutionary implications of their origins

We characterized two novel 7SL RNA-derived short interspersed nuclear element (SINE) families (Tu types I and II) and a novel tRNA-derived SINE family (Tu type III) from the tree shrew (Tupaia belangeri). Tu type I contains a monomer unit of a 7SL RNA-derived Alu-like sequence and a tRNA-derived region that includes internal RNA polymerase III promoters. Tu type II has a similar hybrid structure, although the monomer unit of the 7SL RNA-derived sequence is replaced by a dimer. Along with the primate Alu, the galago Alu type II, and the rodent B1, these two families represent the fourth and fifth 7SL RNA-derived SINE families to be identified. Furthermore, comparison of the Alu domains of Tu types I and II with those of other 7SL RNA-derived SINEs reveals that the nucleotides responsible for stabilization of the Alu domain have been conserved during evolution, providing the possibility that these conserved nucleotides play an indispensable role in retropositional activity. Evolutionary relationships among these 7SL RNA-derived SINE families, as well as phylogenetic relationships of their host species, are discussed.     

Immunological Detection of 22K Protein in Sporulating Cells of Bacillus megaterium ATCC 12872

The synthesis and deposition of 22,000-dalton (22K) spore coat protein were examined immunochemically on the sporulating cells of Bacillus megaterium ATCC 12872 using the antibody to purified 22K spore coat protein. This antibody cross-reacted with 44K and 25K proteins in immunoblot analysis of dormant spore coat proteins. Immunoblot analysis on the sporulating cells showed that 22K protein was detected from t₈ in forespore coat protein fractions. Sandwich enzyme immunoassay revealed that 22K protein in the spore coat protein fraction appeared at t₆ and reached a plateau at t₉, and 22K protein in the mother cell cytoplasmic fraction was detected at only t₇ and t₈ at a very low level.     

Effect of temperature on antibacterial activity of lidocaine to Staphylococcus aureus and Pseudomonas aeruginosa

The effect of temperature on the antibacterial activity of lidocaine to Staphylococcus aureus and Pseudomonas aeruginosa was investigated in vitro. At 10 C at which S. aureus organisms do not grow and might be metabolically inactive, the antibacterial activity of lidocaine to S. aureus was not observed in a concentration of 1%, which was quite antibacterial to S. aureus at 37 C. On the other hand, at 40 C a conspicuously increased antibacterial activity to S. aureus of lidocaine was observed in a concentration of 0.25% which was not antibacterial to S. aureus organisms at 37 C. Similar results were obtained when P. aeruginosa organisms were examined in place of S. aureus, although P. aeruginosa was found to be less susceptible to lidocaine than S. aureus. The clinical significance of the thermal effect on the antibacterial activity of lidocaine was discussed in brief.     

Comparative antigenicity of spore coat proteins from Bacillus species using antibody to spore coat proteins of Bacillus megaterium

Spore coat proteins obtained by extraction with sodium dodecylsulfate/dithiothreitol from six Bacillus spores were compared by immunoblot analysis using antibodies to spore coat proteins from two strains of B. megaterium. Although the extract from spores of each strain had heterogenous proteins with various molecular weights, there were some bands which cross-reacted with specific antibodies from B. megaterium spores. Specific antibody to 48K protein from B. megaterium ATCC 12872 cross-reacted with 17K protein from B. megaterium ATCC 19213, 13K protein from B. cereus and 50K protein from B. subtilis 60015 and B. subtilis NRRL B558. Also, specific antibody to 22K protein from the same strain cross-reacted with 22K and 17K proteins from B. megaterium ATCC 19213 and 13K protein from B. cereus T. Specific antibody to 17K protein from B. megaterium ATCC 19213 reacted with 22K and 19K proteins in addition to 17K protein of own strain, and it was cross-reactive with 16K protein from B. megaterium ATCC 12872, 19K and 27K proteins from B. thiaminolyticus, 13K protein from B. cereus.