A. Ballio

Effects of fusicoccin and some related compounds on etiolated pea tissues

Abstract At a concentration of 1 μg/ml fusicoccin and a number of closely related derivatives stimulate water uptake in cuttings of etiolated pea seedlings. It has been observed that hydrogenation or removal of the t -pentenyl group, as well as partial or total deacetylation of fusicoccin, dihydrofusicoccin, and de- t -pentenylfusicoccin give compounds which show an activity comparable to that of the parent compound. The glucose moiety appears to be necessary for high activity, but the deacetylaglycone is still capable of exerting an effect identical to that of fusicoccin when tested at 10 μg/ml. Acetylation products of fusicoccin and other active derivatives do not stimulate water uptake. Curvature of the apical segment of pea seedlings, repeatedly observed with fusicoccin, prompted a study on isolated internodes of pea seedlings. The phytotoxin produced a pronounced increase of their wet weight and elongation, as well as a definite enhancement of tissue deformability.

The isolation of trehalose and polyols from the conidia of Penicillium chrysogenum thom

Abstract Trehalose, d -mannitol, d -arabitol, meso -erythritol, and glycerol were isolated from the conidia of Penicillium chrysogenum and were quantitatively assayed. Their possible mode of formation and role during germination are discussed.

Chromatographic fractionation and chemical characterization of some oligosaccharides synthesized from lactose by Penicillium chrysogenum thom

Abstract Fractionation by column chromatography on charcoal-celite of β-galactosyl-oligosaccharides produced from lactose by Penicillium chrysogenum has shown that most of the sugars synthesized by cell-free extracts are also present in culture filtrates of the mould grown on lactose-containing media. These represent a suitabl source for the isolation of oligosaccharides in amounts large enough for the study of their chemical structure. The characterization of 3-O-β- d -galactopyranosyl- d -glucose, 6-O-β- d -galactopyranosyl- d -glucose, 6-O-β- d -galactopyranosyl- d -galactose, O-β- d -galactopyranosyl-( i →6)-O-β- d - galactopyranosyl-( i →4)- d -glucose, as well as the probable structures of two oligosaccharides containing fructose and galactose are described.

An operon for histidine biosynthesis in Streptomyces coelicolor

SummaryOn the assumption that a cluster of five his genes (eight cistrons) in S. coelicolor corresponds to an operon, a genetic analysis of a constitutive mutant was carried out. This strain has a multi-site mutation localized at the (conventional) right end of the his cluster and is derepressed for at least two enzymes coded by genes of the cluster. The study of suitable heterozygous clones (heteroclones), showed the mutation to be cis-dominant, suggesting that the operator region is affected. Most likely the strain has a deletion connecting the his operon to an adjacent amm (ammonium requirement) operon as demonstrated by its inability to utilize nitrate as nitrogen source and to complement or recombine with two his cistrons and a near-by amm mutation.

Studies on Ferroverdin, a Green Iron-Containing Pigment Produced by a Streptomyces Wak. Species

The submerged culture production of ferroverdin, an iron-containing green pigment of a novel type, by a new species of Streptomyces Wak. is reported. The morphological properties of this micro-organism are described, and the optimum culture conditions for pigmentation in shake flasks and in stirred fermenters are determined. The Preparation and identification of reductive and alkali degradation products of ferroverdin are reported; on the basis of their structures it is suggested that ferroverdin is the ferrous complex of the p-vinylphenylester of 3-nitroso-4-hydroxybenzoic acid.

A nitrosophenol cobalt chelate produced by a streptomycete

Production in submerged culture of ferroverdin, the ferrous chelate of the p-vinylphenylester of 3-nitroso-4-hydroxy-benzoic acid, has now been obtained in a chemically defined medium. When ferric ions are replaced in this medium by cobaltous ions a brown-red, chloroform-extractable pigment is produced by the micro-organism. Elementary composition, i. r. and n. m. r. spectra of the purified compound, as well as structures of reduction derivatives, suggest that the pigment contains three molecules of the same ligand found in ferroverdin bound to trivalent cobalt.

Purification of a toxin from culture filtrates of Gloeosporium olivarum Alm

FromGloeosporium olivarum Alm. cultures a phytotoxic substance has been isolated, which was obtained in a pure form as a white powder which decomposed at 205–210°C and, after acid hydrolysis, yielded glycine, aspartic acid and an as yet unidentified compound.The purified toxin induced symptoms on tomato cuttings, which were indistinguishable from those caused by the crude culture filtrate of the fungus.SamenvattingUit cultures vanGloeosporium olivarum Alm. is een fytotoxische stof geïsoleerd. Deze werd in zuivere vorm verkregen als een wit poeder, dat ontleedde bij 205–210°C en bij zuurhydrolyse glycine, asparaginezuur en een nog niet geïdentificeerde verbinding leverde.Het gezuiverde toxine induceerde bij afgesneden tomateplanten dezelfde symptomen als ongezuiverde cultuurfiltraten.