Do the beneficial fungi manage phytosanitary problems in the tea agro-ecosystem?

BioControl - In recent years, Fungal Biocontrol Agents (FBCAs) have played a significant role in the biological control of pests and plant pathogens of several economically important crops,...     

Atrial natriuretic factor receptor on cultured Leydig tumor cells: ligand binding and photoaffinity labeling

Atrial natriuretic factor (ANF) is a peptide hormone discovered recently from the heart atrium that possesses potent natriuretic and vasorelaxant activities. Recently we found that ANF markedly stimulates intracellular cGMP and almost completely inhibits cAMP accumulation in testicular interstitial tumor cells [Pandey, K. N., Kovacs, W. J., & Inagami, T. (1985) Biochem. Biophys. Res. Commun. 133, 800-806]. These actions of ANF suggest the presence of ANF receptors in testicular interstitial cells. In this study, cultured murine Leydig tumor cells have been shown to contain specific binding sites for ANF. Saturation binding studies indicated a single class of binding sites with a Kd of 5 X 10(-9) M at a density of 2 X 10(6) sites/cell. The binding of mono[125I]iodo-ANF (125I-ANF) was competed by unlabeled ANF in a dose-dependent manner. Hormones unrelated to ANF such as angiotensin I, bovine luteinizing hormone, and human chorionic gonadotropin were not able to compete against 125I-ANF. The binding of 125I-ANF was rapid, reaching maximum levels in 15 min at 4 degrees C. At 37 degrees C, the cell-bound 125I label was quickly decreased. Pretreatment of cells with NH4Cl, chloroquine, or NaN3 resulted in significant increases in maximum levels of the cell-bound 125I radioactivity. A photoaffinity reagent for ANF receptor was prepared by reacting ANF with succinimido 4-azidobenzoate, and resultant 4-azidobenzoyl- (AZB-) ANF was purified by high-performance liquid chromatography (HPLC). AZB-ANF was radioiodinated by use of chloramine T and purified again by HPLC.(ABSTRACT TRUNCATED AT 250 WORDS)     

Reversal of cerulenin-induced inhibition of phospholipids and sterol synthesis by exogenous fatty acids/sterols in Epidermophyton floccosum

Cerulenin, a specific inhibitor of fatty acids and sterol biosynthesis inhibited the growth of Epidermophyton floccosum, which was reversed when growth medium was supplemented with palmitic acid and sterols. Unsaturated fatty acids partially restored the growth. Cerulenin inhibited both phospholipid and sterol biosynthesis (60-70%) at the minimum inhibitory concentration (0.5 microgram/ml) as demonstrated by [32P]orthophosphoric acid and [14C]acetate incorporation into the respective lipids. Cerulenin-induced inhibition of phospholipid and sterol synthesis was dose dependent up to 0.5 microgram/ml. Exogenously supplied fatty acids and sterols restored the biosynthesis of phospholipids in cerulenin-treated cultures, while that of sterols was enhanced. The biosynthesis of both saturated and unsaturated fatty acids was inhibited by cerulenin.     

Molecular and morphological characterization of somatic hybrids between <Emphasis Type="Italic">Solanum tuberosum</Emphasis> L. and <Emphasis Type="Italic">S. etuberosum</Emphasis> Lindl.

Interspecific potato somatic hybrids between Solanum tuberosum L. (di)haploid C-13 and 1 endosperm balance number non-tuberous wild species S. etuberosum Lindl. were produced by protoplasts electrofusion. The objective was to transfer virus resistance from this wild species into the cultivated potatoes. Post-fusion products were cultured in VKM medium followed by regeneration of calli in MS₁₃ K medium at 20°C under a 16-h photoperiod, and regenerants were multiplied on MS medium. Twenty-one somatic hybrids were confirmed by RAPD, SSR and cytoplasm (chloroplast/mitochondria) type analysis possessing species-specific diagnostic bands of corresponding parents. Tetraploid nature of these somatic hybrids was determined through flow cytometry analysis. Somatic hybrids showed intermediate phenotypes (plant, leaves and floral morphology) to their parents in glass-house grown plants. All the somatic hybrids were male-fertile. ELISA assay of somatic hybrids after artificial inoculation of Potato virus Y (PVY) infection reveals high PVY resistance.     

Laccase production and simultaneous decolorization of synthetic dyes in unique inexpensive medium by new isolates of white rot fungus

Morphological and biochemical analysis of the newly isolated white rot fungal (WRF-1) strain has ability to secrete laccase in the economical medium consisted of synthetic dyes, groundnut shell (GNS) and cyanobacterial biomass (algal bloom) under submerged shaking condition at pH 5.0 and 30 °C ± 2 °C temperature. WRF-1 strain was found to decolorize synthetic dyes efficiently at pH 5.0 and 30 °C ± 2 °C temperature. The laccase activity of strain was purified to homogeneity by chromatography with yield up to 70%. The molecular mass of laccase was found to be 70 kDa by SDS-PAGE and isoelectric point was 4.8. Biotransformation of the dyes was followed spectrophotometrically and dyes were found to decolorize completely after 6 days of fermentation. LC-MS studies were used to decipher the degradation profile of synthetic dyes by WRF-1. Indigo carmine gets degraded to isatin sulfonic acid and 4-amino-3-methylbenzenesulphonic acid whereas methyl orange degraded metabolites were identified as p-N,N′-dimethylamine phenyldiazine and p-hydroxybenzene sulfonic acid. Thus the study would give a road map for the production and application of laccase enzyme on a larger scale using low cost substrate.     

Simultaneous saccharification and protein enrichment fermentation of sugar beet pulp

Summary A product with 40 % protein content was obtained from sugar beet pulp (1.25–2.0 mm) in 48 h one stage (simultaneous) saccharification/fermentation process under optimized conditions using a specific enzyme mixture andCandida tropicalis strain, also saving about 40 % enzymes in comparison to a 2-stage process.