An unusual formaldehyde oxidizing system in Rhodococcus erythropolis grown on compounds containing methyl groups

Abstract During utilization of compounds containing methyl groups, the non-methylotrophic bacteria Rhodococcus erythropolis oxidized the methyl groups entirely to carbon dioxide. This oxidation was linked to the presence of an NAD-dependent formaldehyde dehydrogenase activity which was lost on dialysis. The activity could be restored by the addition of boiled extract but not by adding the known cofactors glutathione or tetrahydrofolate.
A further dehydrogenase activity with formaldehyde as substrate was found in ethanolgrown cells. This activity could be differentiated from that in methyl group metabolizing cells.     

The phospholipid requirement of the (Ca + Mg)-ATPase from human platelets

The phospholipid requirement of the (Ca²⁺ + Mg²⁺)-ATPase present in a membrane fraction from human platelets was studied using various purified phospholipases. Only those phospholipases, which hydrolyse the negatively charged phospholipids, inhibited the (Ca²⁺ + Mg²⁺)-ATPase activity. The ATPase activity could be restored by adding mixed micelles of Triton X-100 and phosphatidylserine or phosphatidylinositol. Micelles with phosphatidic acid, phosphatidylcholine, phosphatidylethanolamine or sphingomyelin could not be used for reconstitution and inhibited the activity of the native enzyme.     

Temperature-Enhanced Osmotic Growth Requirement of Crithidia*†

SYNOPSIS. An osmotic growth requirement for the trypanosomatid Crithidia fasciculata became conspicuous at 32 C. Osmo-supportive compounds were surveyed at 28 vs. 33 C, in “low-osmotic” defined medium. Effective osmotic support was provided by many compounds, e.g., glycerophosphate, sorbitol, mannitol, glycerol, Na isethionate, glycine, arginine, KCl, NaCl, NH₄Cl, and K₂SO₄. The nonspecificity of the requirement was thus evident, but inactivity of the presumably poorly adsorbable pentaerythritol indicated that osmotic pressure was a likely but insufficient condition for satisfying the temperature-enhanced growth requirement most clearly expressed as a need for osmotic support. Fortification of the medium with a combination of glycerophosphate, glycine, glycerol, and Tween 80 permitted good growth at 35 C. Possible relations between the temperature-enhanced osmotic requirement cell membrane damage, and morphological phases of Trypanosoma and Leishmania are discussed.     

Effect of plant growth regulators and basal media onin vitro shoot proliferation and rooting ofMyrtus communis L.

The influence of macronutrients and growth regulators on in vitro shoot proliferation and rooting of an East Spanish population ofMyrtus communis L. were studied. Preincubation of field material on a medium without mineral salts prevented the browning from phenolic exudates. For multiplication, nodal segments of 5 mm fromin vitro produced shoots were cultured on Murashige and Skoog (MS), Schenk and Hildebrandt (SH) and Heller (H) media (full strength or diluted to 1/2 or 1/4), with 6-benzylaminopurine (BAP) at concentrations 4.4, 13.3 and 22.2 ΜM or kinetin (K) at concentrations 4.7, 14.0 and 23.2 ΜM. The optimum shoot proliferation was on quarter-strength MS medium with 4.4 ΜM BAP, whereas the maximum number of nodal segments was produced on half-strength MS medium with 4.4 ΜM BAP. Rooting of shoots was obtained by adding 2.5 – 24.6 ΜM indole-3-butyric acid (IBA) and broad range of macronutrients; Lloyd and McCown (WPM) and Gresshoff and Doy (GD) media both full strength or diluted to 1/2 were optimum. No rooting was obtained in the presence of α-naphthaleneacetic acid (NAA). Acknowledgements: This study was supported by a grant from Conselleria de Cultura, Educació i Ciència de Ia Generalitat Valenciana. The authors are grateful to Man Cannen Perea for her helpful comments.     

Feed efficiency and body composition of selected and unselected mice

Summary An examination was carried out of the feed intake, feed efficiency and body composition of selected and unselected mice. It was demonstrated that selected mice utilised food more economically, and, in total, produced more protein than the control animals. However, selection had a negative influence on the percentage content of protein and ash. Also, selection caused greater adiposity of selected females and a greater water content in the bodies of selected males (in %).This work was partly supported by grant No. FG-Po-348 (JB-13), Project No. PL-ARS-68.     

The effects of fragmentation and disturbance of rainforest on ground-dwelling small mammals on the Robertson Plateau, New South Wales, Australia

We surveyed ground-dwelling small mammals in twenty-four rainforest remnants which were virtual islands surrounded by farmland on a plateau on the east coast of Australia. We investigated the effect of island size, level of disturbance, isolation and microhabitat on the abundance and species richness of the mammals. The remnants ranged from 0.3 to 29 ha, resulting from fragmentation during 175 years of European occupation. Two rodent species (Rattus fuscipes[Waterhouse, 1839] and R. rattus[Linnaeus, 1758] ) and one marsupial insectivore (Antechinus stuartii Macleay, 1841) were trapped in these remnants, with an additional species (A. swainsonii[Waterhouse, 1840] ) several kilometres away in rainforest on the escarpment of the plateau. Small-mammal species richness was low, but the native species (R. fuscipes and A. stuartii) were abundant. Three-way analyses of variance demonstrated that species richness and abundance decreased significantly with decreasing remnant size and increasing disturbance, but showed no distance effect. The abundance and richness of native species responded even more significantly. The interaction between the first two effects is important. Small remnants are affected most detrimentally by increasing disturbance, large remnants are less affected, and medium sized remnants show intermediate effects. The introduced R. rattus which was least abundant in large remnants, but more abundant in distant than near remnants, was also more abundant in those with major disturbance. The single most important variable in step-wise, multiple linear regression analyses was the logarithm of remnant area not influenced by edge effects, explaining 39% of the variance in species richness, 57% for native species richness and 46% for A. stuartii abundance. Disturbance related variables additionally contributed from 12 to 30% of the variance in dependent variables, while habitat variables explained between 22 and 48% of the variance, and accounted for two thirds of the explainable variance in R. fuscipes abundance. The implications of our results for wildlife conservation on the plateau are discussed.