Some new species of Penicillium recovered from the atmosphere in Madrid and from other substrata

Six new species ofPenicillium Linkex Fries are described and illustrated. Four of them have been recovered from the atmosphere in Madrid, Spain, the other two species were isolated from must and from soil respectively. They clearly differ from all species of the genus described so far and are, therefore described and proposed as new taxa:Penicillium gerundense sp. nov.,Penicillium valentinum sp. nov.,Penicillium alicantinum sp. nov.,Penicillium malacaense sp. nov.,Penicillium tarraconense sp. nov., andPenicillium vasconiae sp. nov.     

Four new species of Penicillium isolated from the air

Four new species of Penicillium Link ex Fries are described and illustrated. All of them but one have been isolated from the atmosphere in Madrid, Spain. They clearly differ from all species of the genus described so far and are, therefore, described and proposed as new taxa: Penicillium aurantio-flammiferum sp. nov., Penicillium gallaicum sp. nov., Penicillium granatense sp. nov., and Penicillium ilerdanum sp. nov.     

Air-borne fungi in the air of Barcelona (Spain). IV. Various isolated genera

During a two-year survey on the air-borne fungi in the atmosphere of Barcelona (Spain), the following genera were isolated in decreasing order: Aureobasidium, Rhizopus, Mucor, Arthrinium, Phoma, Fusarium, Trichoderma, and Botrytis.     

Morphological changes in strains of Aspergillus flavus link ex fries and Aspergillus parasiticus speare related with aflatoxin production

Two strains ofAspergillus flavus Linkex Fr. and two strains ofA. parasiticus Speare were cultured on crushed moist wheat (Triticum durum var. Pané no. 247) for aflatoxin production studies in correlation with morphological changes. The toxicogenic strains were adapted to the substratum by means of successive transfers at regular intervals (72 h.)The amount aflatoxins synthesized by the toxicogenic strains decreased gradually after succesive subculturing. The decrease was accompanied by marked morphological changes. One of the strains studied,A. flavus NRRL 3251, lost completly the capacity of aflatoxin synthesis after several subcultures, presenting at the same time strong morphological variations.A. flavus CBS 120.62 also lost its toxicogenicity after six subcultures.     

Muscle fibrillation caused by cytochalasin-B applied to the motor nerve.

Cytochalasin-B, a drug known to interfere with axoplasmic transport, evoked fibrillary potentials in the geniohyoid muscle when applied to its motor nerve. Despite this denervation-like effect, neuromuscular transmission remained normal. Some contractile characteristics of the muscle were studied. It was found that contraction time, isometric twitch tension, and half-relaxation time were not altered by the drug treatment. The present findings show that neurogenic molecular factors conveyed by axoplasmic transport to the nerve terminal are involved in the regulation of some muscle membrane characteristics but do not modify the muscle contractile features.     

Cross-links in African swine fever virus DNA.

African swine fever virus DNA sediments in neutral sucrose density gradients as a single component with a sedimentation coefficient of 60S. In alkaline sucrose density gradients, this material shows two components with sedimentation coefficients of 85S and 95S, respectively. The sedimentation rate value of alkali-denatured virus DNA in neutral sucrose density gradients and the renaturation velocity of denatured DNA show that is reassociated much faster than expected from its genetic complexity. This behavior is compatible with the existence of interstrand cross-links in the molecule. We also present results which suggest that there are only a few such cross-links per molecule, that they are sensitive to S1 nuclease digestion, and that they are probably located next to the ends of the DNA.     

The arrangement of nucleotides in the coding regions of natural templates

Summary The relation of the nucleotide sequences in the coding regions of natural templates and of the short nucleotide sequence in 3 terminus of 16 S ribosomal RNA was found to differ from random pattern. The observation is interpreted in terms of both the ribosomal interactions and the molecular evolution.     

An autecological study of Palicourea riparia Bentham as related to rain forest disturbance in Puerto Rico

Summary The present study is an attempt to understand biology of Palicourea riparia Bentham relative to the process of recovery following disturbance in a tropical rain forest in Puerto Rico. In this species seed germination and seedling maintenance are favored by environmental conditions associated with disturbance, yet germination and seedling persistence are significant in undisturbed forest conditions. The pattern of seed germination indicates that (1) the seeds possess a dormancy mechanism, (2) dormany is not evenly distributed within a seed population, and (3) some seeds can remain viable if buried in the soil for at least three years. Results from reciprocal transplant studies indicate that there has been no differentiation into growth ecotypes in this species. Photosynthetic rates are very low under both field and laboratory conditions. In the laboratory, photosynthetic rates are consistently enhanced by increases in light intensity. It is concluded that P. riparia is a species of wide ecological amplitude that acts as a gap opportunist.     

Effects of abscisic acid,gibberellic acid and fusicoccin on the transmembrane potential during the early phases of germination in radish (Raphanus sativus L.) seeds

During germination, the transmembrane electric potential (PD) of cortical cells of the embryonal axis of radish seeds (Raphanus sativus L.) rises from-120 mV initially to a maximum of-150 mV after 5 h incubation, then falls again to stable values of around-120 mV. Treatments inhibiting germination block the transitory PD increase. Administration of uncoupling agents or low temperatures, during the process of germination, produces a marked fall of the PD transitory increase. Abscisic Acid has a parallel inhibitory effect on PD and germination, while fusicoccin produces a rise in both; administration of abscisic acid with fusicoccin inhibits germination, while the PD remains at the high levels given by fusicoccin. These results are discussed in relation to ion exchange at membrane level.Abbreviations ABA abscisic acid - FC fusicoccin - GA₃ gibberellic acid - PD electric potential difference (between the vacuole and the external medium) - CH cycloheximide - DNP dinitrophenol - FCCP (p-trifluormethoxy)-carbonylcyanide-phenylhydrazone - DCCD N,N-dicyclohexylcarbodiimide