Changes in organic matter composition of forest soil treated with a large amount of urea to promote ammonia fungi and the abilities of these fungi to decompose organic matter

Organic matter composition (lignin, holocellulose, 50% (v/v) methanol extract, water-soluble carbohydrate (WSC) and phenolics (WSP), petroleum ether extract, and ash) of A₀ layer soil treated with 700 g/m² of urea to promote ammonia fungi was investigated in a Japanese red pine (Pinus densiflora) forest. Nine species of fungi were found during the study period of 18 months after the treatment. Of these, seven species belong to the ammonia fungi. WSC content of the treated soil was lower than that of the control. Methanol extract content increased initially after the treatment, then decreased to below the control level. There were no consistent differences in other components between the treated plot and the control. The abilities to decompose cellulose, lignin, chitin, protein and lipid in 18 strains in 10 species of the ammonia fungi were also screened. Cellulose was not lysed byPseudombrophila deerata, Hebeloma spp. andLaccaria bicolor. Strong lignolytic activity was shown byLyophyllum tylicolor, Coprinus echinosporus andP. deerata. Chitin was decomposed byAmblyosporium botrytis, L. tylicolor, C. echinosporus andHebeloma vinosophyllum. All strains possessed proteolytic and lipolytic activities. Supply of glucose to the culture media resulted in weaker enzyme activities except for lignolytic ability.     

Rhodium-catalyzed synthesis of 2(5H)-furanones from terminal alkynes and non-substituted alkynes under water-gas shift reaction conditions

Rhodium-catalyzed synthesis of 2(5H)-furanones from alkynes under water-gas shift reaction conditions was studied. By improving the reaction conditions for internal alkynes reported previously, the reaction could be extended to terminal alkynes. Terminal alkynes are selectively converted into 3- and 4-substituted 2(5H)-furanones (2 and 3). When acetylene itself is used, 2(5H)-furanone (2n) is obtained in a good yield. Examination of reaction solutions by IR spectroscopy and some other experimental findings suggest that the active species would be an alkyne-coordinated monomeric rhodium anion. A new reaction path is proposed.     

Conformation of (2→1)-β-d-fructan in aqueous solution

The conformation and dilute solution properties of (2→1)-β-d-fructan in aqueous solution were studied by gel permeation chromatography, low-angle laser light-scattering photometry, viscometry, small-angle X-ray scattering and electron microscopy. Fractions covering a broad range of weight-average molecular weights (M_w) from 1.49 × 10⁴ to 5.29 × 10⁶ were obtained from a native sample by ultrasonic degradation and fractional precipitation. For M_w < 4 × 10⁴, the intrinsic viscosity [η] varies with M_w^0.71, indicating that the fructan chain behaves as a random coil expanded by an excluded-volume effect in this molecular weight region. For M_w > 10⁵, [η] exhibits an unusually weak dependence on M_w and finally becomes almost independent of molecular weight. This behaviour is interpreted in terms of a globular conformation of the high-molecular-weight fructan molecules. Small-angle X-ray-scattering measurements and electron microscopic observations support this interpretation of the values of [η] observed.     

A rapid and simple method for plasmid copy number comparison

Summary A rapid, simple, and sensitive method for plasmid copy number comparison was developed. The extracted plasmids from the same amount of cells were subjected to agarose gel electrophoresis and the gels photographed. The photographs were processed by a Macintosh image analyser to enumerate the densities of plasmid bands. As a size reference, λ-DNA digested with a restriction enzyme was used. The densities divided by size of plasmids (base pair) would represent relative values of their copy numbers.     

Suppression of lymphocyte spontaneous proliferative response by proteolipid protein peptide in patients with HAM/TSP

To understand the immune mechanism suggested in HTLV-I-associated myelopathy (HAM/TSP), we investigated T cell response to proteolipid protein (PLP). Because of high autologous proliferative response (APR) of peripheral blood mononuclear cells (PBMC) in culture, the lymphocyte proliferation assay was not useful in this disease. Unexpectedly, however, APR was profoundly (70–98%) suppressed in 6 of 9 cases when PLP peptide 105-124 was added in the culture. PLP peptide 85-104 or 145-159 also suppressed APR in a few cases. Time course study showed that the peptide-mediated suppression became apparent after day 4 in culture. The results can be interpreted as that suppressor cells recognizing the PLP peptides were present in the PBMC of HAM/TSP patients and suppressed the APR as the consequence of antigen specific response. This may indicate that a T cell response to certain PLP determinants is involved in the pathomechanism of HAM/TSP at least in part. Molecular mimicry between PLP and HTLV-I mayaccount for the T cell sensitization to PLP in HAM/TSP.Special issue dedicated to Dr. Marjorie B. Lees.     

Adenylate Uptake by Proplastids from Cultured Cells of Tobacco {Nicotiana tabacum L. cv. BY2) Indicates That an Adenylate Translocator is Present in All Types of Plastid

The presence of an adenylate translocator in the envelope membranesof proplastids isolated from the cultured cells of tobacco (Nicotianatabacum L. cv. BY2) was examined by means of transport experimentsusing the silicone oil filtering centrifugation technique. Itwas observed that proplastids can import [³H]ATP, [³H]ADP, [³H]AMPand less specifically ADP-[¹⁴C]Glc which can eventually be usedfor starch biosynthesis. The effects of specific inhibitorsof the mitochondrial adenylate translocator, i.e. atractyloside,bongkrekic acid and carboxyatractyloside were tested. Similarto the case of amyloplasts isolated from the cultured cellsof sycamore and chloroplasts isolated from spinach leaves, onlyATP and ADP-Glc uptake were shown to be partially inhibitedby carboxyatractyloside. On the other hand, neither atractylosidenor bongkrekic acid exerted a significant inhibitory effecton adenylate uptake. (Received August 8, 1992; Accepted November 26, 1992)     

cDNA Cloning and Expression of the Plastidic Copper/Zinc-Superoxide Dismutase from Spinach (Spinacia oleracea L.) Leaves

A cDNA clone for copper/zinc-superoxide dismutase (Cu/Zn-SOD)was isolated from spinach (Spinacia oleracea L.) leaves. Itsnucleotide sequence showed that it codes for a precursor polypeptideof 222 amino acids, including the NH₂-terminal 68-residue extensionwhich corresponds to a plastidic transit peptide. Northern hybridization,using plastidic and cytosolic Cu/Zn-SOD cDNAs as the probes,revealed that these two genes are differentially expressed inthe roots and leaves of spinach. ¹Present address: Department of Biochemistry and Microbiology,Cook College, Rutgers University New Brunswick, NJ 08903-0231,U.S.A.     

cis-Elements and Protein Factors Related to Regulation of Transcription of Arylsulfatase Gene during Sea Urchin Development

Eight restriction fragments (I–VIII) were prepared to cover a whole span of the enhancer region in the upstream of the Ars gene of the sea urchin, Hemicentrotus pulcherrimus , and their abilities to influence on the Ars gene expression were estimated by CAT assay. Only three fragments (III, IV and V) encompassing a 0.6 kb region between −2.8 kb and −2.2 kb stimulated CAT expression. By mobility shift assays, it was found that the Ars enhancer region is composed of multiple cis -acting elements that interact with nuclear proteins in a sequence-specific manner. Among them, two sequences, a G-string and a GATCTCCCC, were determined by DNA footprinting as sites of protein-DNA interaction. The DNA-binding factor prevalence changed ontogenically in three different patterns. Possible activation of DNA-binding proteins through their modification is discussed.