Fermentation of methanethiol and dimethylsulfide by a newly isolated methanogenic bacterium

From dilution series in defined mineral medium, a marine iregular coccoid methanogenic bacterium (strain MTP4) was isolated that was able to grow on methanethiol as sole source of energy. The strain also grew on dimethylsulfide, mono-, di-, and trimethylamine, methanol and acetate. On formate the organism produced methane without significant growth. Optimal growth on MT, with doubling times of about 20 h, occurred at 30°C in marine medium. The isolate required p-aminobenzoate and a further not identified vitamin. Strain MTP4 had a high tolerance to hydrogen sulfide but was very sensitive to mechanical forces or addition of detergents such as Triton X-100 or sodium dodecylsulfate. Methanethiol was fermented by strain MTP4 according to the following equation:

Formation of dimethylsulfide and methanethiol from methoxylated aromatic compounds and inorganic sulfide by newly isolated anaerobic bacteria

Formation of gas and of methylated sulfur compounds was observed in anaerobic enrichment cultures with methoxylated aromatic compounds as substrates. Via direct dilution of mud samples in defined reduced media supplemented with trimethoxybenzoate or syringate two new strains of anaerobic homoacetogenic bacteria (strain TMBS4 and strain SA2) were obtained in pure culture. Both strains produced dimethylsulfide and methanethiol during growth on methoxylated aromatic compounds. Growth tests and determination of stoichiometries demonstrated that the volatile sulfur compounds were formed from the methyl group at the aromatic ring and the sulfide added as reducing agent to the medium (R = aromatic residue): 2 R - O - CH₃ + H₂ S 2 R - OH + (CH₃)₂SDimethylsulfide was the major organic sulfur compound formed, whereas methanethiol appeared only as intermediate in small quantities. The isolates grew also with trihydroxybenzenes such as gallate, phloroglucinol, or pyrogallol without formation of methylated sulfur compounds. The aromatic compounds were degraded to acetate. The freshwater strain TMBS4 also fermented pyruvate. Other aliphatic or aromatic compounds were not utilized. External electron acceptors (sulfate, nitrate, fumarate) were not reduced. Both strains were mesophilic and formed rod-shaped, non-motile, Gram-negative cells. Spore formation was not observed. Tentatively, both isolates can be affiliated to the genus Pelobacter.Abbreviations TMB 3,4,5-trimethoxybenzoate - MT methanethiol - DMS dimethylsulfide     

广西窄腹茧蜂属一新种：膜翅目：茧蜂科：茧蜂亚科

茧蜂亚科已知有123个属(Quicke,1987),其中窄腹茧蜂属Angustibracon Quicke是Quicke(1987)根据分布在印度的1个种Bracon leptogaster Cameron重新组合为1个新属而建立,迄今已定名种仅此1种。我们整理广西茧蜂标本时,鉴定出该属1新种。这是本属种类在我国分布的首次报道,现将该属属征和新种形态记述如下。新种模式标本存湖南农学院昆虫标本室。     

Lithium-induced decrease of brain inositol and increase of brain inositol-1-phosphate is transient

The effects of a single does of LiCl (2.5 or 10 mEq/kg) on brain inositol and inositol-1-phosphate (Ins1P), intermediates of brain phosphoinositude (PI) turnover, were determinated in male Han: Wistar rats. There was a remarkable, 36–58 fold elevation of brain Li⁺ as the single does of LiCl was increased 4-fold. Moreover, the accumulation of brain lithium was slow during repeated administration of LiCl. Brain lithium did not correlate with changes in brain PI turnover either after a single or repeated doses. Thus, after a single does of LiCl the increases in brain Ins1P were much less than the decreases in brain inositol. Also, brain inositol was significantly decreased only with the high dose of LiCl whereas brain Ins1P accumulation was more prominent with the lower dose. Moreover, repeated daily doses of LiCl only transiently increased brain Ins1P at 1 and 7 d whereas inositol remained at control levels throughout the 14 d observation period. Lithium probably caused the transient decrease in brain inositol by inhibiting several enzymes, in addition to the inhibition of myo-inositol mono-phosphates, in the PI cycle. Moreover, a slow dampening down of PI turnover by lithium, possible via an inhibitory action on G-protein-coupling, may also explain the present findings.     

利血平和丘脑下部促黄体素释放激素类似物(LHRH-A)对大鳞副泥鳅促性腺激素细胞的分泌活动和排卵的促进作用

利血平能使神经分泌细胞的儿茶酚胺贮存量减少甚至消耗殆尽,导致多巴胺作为GRIF的作用减弱,从而显著增强LHRH-A促进GtH分泌和诱导排卵的效应。对大鳞副泥鳅,利血平和LHRH-A同时注射或者利血平比LHRH-A提前3小时注射,都能激活GtH细胞,显著增强其分泌活动并诱导排卵。利血平的最低有效剂量为1—5微克/克体重。利血平(25微克/克体重) LHRH-A(0.05微克/克体重)的催产效果和多巴胺拮抗物pimozide(1微克/克体重) LHRH-A(0.05微克/克体重)的催产效果一样,排卵率都达到了100％。     

ENZYMES OF PHOSPHOINOSITIDE METABOLISM DURING RAT BRAIN DEVELOPMENT

—The activities of four enzymes concerned with inositol lipid metabolism have been determined in homogenates of rat brains of different ages. The enzymes are CDP-diglyceride inositol phosphatidate transferase, phosphatidylinositol kinase, diphosphoinositide kinase and triphosphoinositide phosphomonoesterase. The activities of all the enzymes increased with age. Phosphatidylinositol kinase activity rose most sharply well before myelination, reaching a maximum at about 6 days of age. Diphosphoinositide kinase and triphosphoinositide phosphomonoesterase activities increased most rapidly during myelination. The increase in CDP-diglyceride inositol phosphatidate transferase showed no definite association with any period of development. It is concluded that triphosphoinositide metabolism is associated with myelin or a closely related structure.     

Consequences of herbivory in the mountain birch (Betula pubescens ssp tortuosa): importance of the functional organization of the tree

Summary Three types of experiments indicate that the functional organization of the mountain birch may influence the ways in which the tree responds to simulated or natural herbivory. The first experiment showed that herbivory to both short and long shoot leaves affects plant development but, because growth largely proceeds by resources of the previous year, is manifested only in the year following the damage. The second experiment showed that even partial damage to a single long shoot leaf caused the axillary bud of that leaf to produce a shorter shoot the next year. Therefore, the value of a leaf depends also on the organ which it is subtending. In the third experiment we manipulated the apical dominance of shoots in ramets and caused improvement to leaf quality in extant shoots. Ramets within a tree responded individually, probably mediated by disturbance of the hormonal control because removal of apical buds elicited the response although removal of the same number of basal buds did not. Induced amelioration is a different response to induced resistance. The two responses are triggered by different cues and may occur in the same plant. By altering hormonal balance of shoots it is potentially possible for herbivores to induce amelioration of food quality. The ways in which herbivory is simulated may explain variability of results obtained when herbivory-induced responses in plants have been studied.     

Effect of physostigmine on relative acetylcholine output induced by systemic treatment with scopolamine in in vivo microdialysis of rat frontal cortex

By means of an in vivo brain microdialysis, the effect of different concentrations of physostigmine on the acetylcholine level in the dialysate of rat frontal cortex was studied. Perfusion of the various degrees of physostigmine (eserine) concentration (10 nM−10 μM) into the cortex through the dialysis membrane increased the basal acetylcholine level in a dose-dependent manner. In the presence of 10 nM, 0.1 μM and 10 μM physostigmine in the perfusate, systemic treatment with scopolamine (0.5 mg/kg, i.p.) increased 200, 270 and 510%, respectively, the relative acetylcholine level in the dialysates in comparison with the corresponding basal levels, while in the absence of physostigmine the treatment increased it only 40%. From these results, it appears that perfusion of physostigmine at a variety of concentrations, changes not only the basal level of acetylcholine induced by the inhibition of acetylcholinesterase but also the relative acetylcholine output induced by systemic treatment with scopolamine.     

Analysis of the biosynthetic process of cellulose and curdlan using C-labeled glucoses

In order to elucidate the biosynthetic process of cellulose and curdlan, ¹³C-labeled polysaccharides were biosynthesized by Acetobacter xylinum (IFO 13693) and Agrobacterium sp. (ATCC 31749), from culture media containing -(1-¹³C)glucose, -(2-¹³C)glucose, -(4-¹³C)glucose, or -(6-¹³C)glucose as the carbon source, and their structures were determined by ¹³C NMR spectroscopy. The labeling was mainly found in the original position, indicating direct polymerization of introduced glucoses. In addition, the transfer of labeling from C-2 to C-1, C-3 and C-5, from C-4 to C-1, C-2 and C-3, and from C-6 to C-1 was found in celluloses. In curdlan, the transfer of labeling from C-1 to C-3, from C-2 to C-1 and C-3, from C-4 to C-1, C-2 and C-3, and from C-6 to C-1 and C-3 was observed. From analysis of this labeling, the biosynthetic process of cellulose and curdlan was explained as involving six routes. The percentages of each route via which cellulose or curdlan is biosynthesized were estimated for upper (C-1 to C-3) and lower portions (C-4 to C-6) of glucosidic units in the polysaccharides. It is noted that very few polysaccharides are formed via the Embden-Meyerhof pathway. The lower half (C-4 to C-6) structure of introduced glucoses is well preserved in the polysaccharides.