Control of Histidine Biosynthesis in Streptomyces Coelicolor

Abstract

Some data on the benthic flora of Pantelleria Harbour (Channel of Sicily, Mediterranean).—The benthic flora of the harbour of Pantelleria includes: 10 Myxophyceae, 56 Rhodophyceae, 44 Diatomeae, 19 Phaeophyceae, 18 Chlorophyceae and 2 Angiospermae. The Rh/Ph value (2.9) is in agreement with the values found from the open-sea. A chorological examination shows a dominance of Atlantic-Mediterranean species (54.36%).     

Ricerche Sulla Vegetazione Della Valsesia. VII. Notholaena Marantae (L.) Desv. in Valsesia

Abstract

Researches on the vegetation of Valsesia. VII. «Notholaena marantae» (L.) Desv. in the Sesia Valley. — It's hereby described a station of Notholaena marantae (L.) Desv. near «Giavina Rossa» (Valsesia-Piedmont, Italy). This is probably the only place in the whole valley. The fern grows in a kind of ground formed by peridotitic rocks and on a little dry wall supporting the debris. The fern presence in a wooden valley, and under an oceanic climate could be a very interesting subject for hystorical geobotanic researches.     

Evoluzione Della Cerchia Legnosa in Quercus Aegilops L. a Tricase

Abstract

The author has examined the cambial activity and the formation of the annual ring in Quercus aegilops from February 1954 to February 1955. Material was collected at Tricase (Lecce) the only Italian locality where this oriental species grows although it is doubtful whether it is spontaneous.

Cambial activity starts in the middle of April both in the main stem and in the branches following flowering and bud development. It goes on for about five months until the second half of August forming a complete growth ring. This annual ring shows the normal sequence of early wood with wide vessels formed during the second half of April and the whole of May, intermediate wood with medium and small size vessels, parenchima, and fibres formed in June-July, and late wood with few small size vessels, parenchima, and fibres formed from the end of July to middle August.

There is no reawakening of cambial activity in autumn even if the climatic conditions are favourable. Tylosis are very easily formed in the wood vessels and by this process the plant can withstand the drought of the Apulian summer.     

Studio preliminare sulla tipologia della vegetazione sommersa del Canale di Sicilia e isole vicine

Abstract

Preliminary studies on the marine phythobenthic communities in the Straits of Sicily and adjacent islands. — The results of algological researches carried out by the Gruppo di Algologia of the S.B.I. in the Straits of Sicily and adjacent islands are reported. 288 species have been collected, 275 of which have been identified: 160 were Rhodophyta, 62 Phaeophyta, 32 Chlorophyta, 16 Cyanophyta and 2 Angiospermae. The vegetational research leads to the following conclusions: 1 - the harbour areas (Pantelleria, Malta: loc. 1 and 11) show a nitrophile vegetation, particulary near La Valletta where an almost pure population of Pterocladia pinnata is found; 2 - there are important biogeographical differences between Pelagie islands (Lampedusa, Linosa) and Pantelleria. In fact the former ones have an algal flora composed mostly of eastern mediterranean species, whilst the latter shows strong affinities with the north-african basin, as is demonstrated by the rich well developed belt of Cystoseira sedoides; 3 - several species of atlantic origin, such as Callophyllis laciniata, Peyssonnelia coriacea, P. inamoena and Castagnea chordariaeformis, have been found on the banks (loc. 3, 6, 7).     

Sul Controllo Della Glicolisi Nel Lievito

Abstract

On the control of carbohydrate utilization in yeast. — The results of a previous investigation showed that in higher plants the stimulating action of 2,4 dinitrophenol (DNP) on oxygen uptake and glycolysis is accompained by a fall of the level of reducing sugars, due to an increase of their respiratory utilization, and thus — according to every evidence — of the rate of hexose phosphate synthesis.

In the present work, the occurrence of a similar phenomenon in yeast (where the inhibiting effect of DNP on glucose uptake is not so much marked as in higher plant tissue) was investigated.

Here again DNP, at a 10^-4M concentration, induced a rapid decrease of the disaccaride trehalose and of glycogen, such as to account for the increased rate of respiration and of fermentation. The ratio between the contributions to CO₂ of Carbons 1 and respectively 6 of glucose was not significantly changed by DNP, which suggests that at least part of the DNP induced increase of glycolysis was mediated by the Embden Meyerhof pathway, and thus that a larger amount of fructose diphosphate was formed in the presence of the uncoupler.

In other experiments the effects of DNP on the dissimilation of C¹⁴ labeled glucose, glycerol and pyruvate to CO₂ and ethanol, and on the incorporation of the radioactive isotope into various fractions, 15 minutes after feeding the labeled substrates, was investigated. It was found that:

1) Glucose and glycerol uptake is not markedly inhibited by DNP at the concentration employed (^10–4M).

2) In the absence of DNP, a considerable portion of the radioactivity fed as glucose or glycerol and taken up by the yeast cells is recovered in the glycogen and trehalose fractions. (35% of the glucose, and 22% of the glycerol taken up). This is also observed for carbons 2 and 3, but not for carbon 1 of pyruvate. This indicates a reversibility of the glycolitic processes comprehended in the region between phospho-enol pyruvate andpolysac-carides; while the pyruvate kinase reaction appears to represent a sharp barrier at the « lower » end of glycolysis.

3) DNP almost completely inhibited the incorporation of C¹⁴ from glucose and glycerol into glycogen and trehalose, although it increased the rate of its dissimilation to CO₂ and ethanol. The total amount of glucose and glycerol transformed in the various metabolites (and thus — according to every evidence — phosphorylated) was somewhat lowered and proteins synthesis severely depressed. These effects are interpreted as due to the uncoupling action of DNP at the mitochondrial level, and to the consequent general decrease of the ATP and UTP levels required for protein and for polysaccharide synthesis.     

Le Plantule Della Flora Trapanese

Summary

Secondary wood growth in both a ♂ and a ♀ plant of Schinus Molle has been studied in Bari, Puglia.

The bulk of the secondary wood has been found to be made up of substitution fibres full of starch grains, which it would be more appropriate to call fusiform wood parenchyma cells (according to the « Glossary of Terms Used in Describing Woods», in Tropical Woods, N° 36, 1933).

There are no annual rings: the thickening is due to the addition of successive «growth layers», 3 or 4 per year.

The cambium does not undergo any evident resting period, neither in summer nor in winter, but only periods of suspended activity: the periods of suspended activity do not occur simultaneously in the ♂ and ♀ plants, but in different months.

Each period of cambial activity passes through the three stages of initial, maximum, and decreasing intensity and lasts for 2–3–4 months depending on the season and the sex.

Tipically the growing period starts with the deposition of new elements; next follows lignification of these same elements; during the third stage starch grains appear in the fusiform and radial parenchyma cells of the newly formed wood.

During 1952, 4 growth layers have been formed in the ♂ and 3 in the ♀ plant. In general each episode is slower and more diluted in time in the ♀ plant as compared to the ♂ one. A diversity in cambial behaviour as regards spring reawakening, between the two sexes of dioiceous plants had been already observed in Rhamnus Alaternus (De Paolis, 1949); in both species the ♂ plant appears to be more sensitive and more speedy in its reactions than the ♀ one.

The author does not know of any research on cambial activity in S. Molle carried out in Peru, the native land of this species. Comparing its cambial activity as revealed by the present researches with that of other evergreen plants spontaneous in Puglia the existence of an essential difference is demonstrated: while in S. Molle cambial activity is subcontinuous, in the Mediterranean evergreen trees and shrubs so far studied the cambium undergoes two resting periods, one in winter, and a more or less well defined one in summer. Moreover cambial activity in S. Molle can be taken as continuous if the plants of both sexes are considered, owing to their asinchronism (the same phenomenon happens in flowering times). This lack of a well defined growth cycle corresponds to a similar lack of a well defined seasonal cycle in the climate of the interandine Peruvian valleys, the original habitat of S. Molle, where the mean temperatures of the coldest months vary from 5,8° C to 11,9° C, while those of the hottest months vary from 10,3° C to 15,9° C, with yearly excursions of 4,5 to 5° C.

On the other hand the type of secondary th ckening by successive apposition of wood layers recalls closely that of a group of Mediterranean plants studied in Puglia, that is Ficus carica (Giannuoli, 1949), Olea europaea (Armenise, 1950), and Phillyrea latifolia (Maranò, 1953). In the case of these species the authors had suggested that they belonged, or were related to genera which had originated or developed in regions lacking a well defined seasonal climatic cycle. This hypothesis is confirmed by the fact that S. Molle, a recently imported tropical plant has maintained in our Mediterranean climate not only its original type of secondary thickening, but also its original growth rythm. S. Molle can be considered an experimental test of an hypothesis based so far on the interpretation of observation data.     

Althenia Filiformis Petit: Azione Della Temperatura e Dell'Acqua di Mare Sulla Germinazione

Abstract

Effects of temperature and sea water on germination behaviour of Althenia filiformis Petit seeds. - Germination capacity and energy of Althenia filiformis Petit seeds have been investigated, 90 and 180 days after ripening, to carry out a preliminary study on ecology of this species.

This species, halophite and hydrophyte, is spreaded along the coast shores of middle-west mediterranean sea and atlantic shores of Morocco, Spain, Portugal and France.

Seeds were soaked in the dark, at 10°, 20°, 30°C, in solutions at different salt concentration: sea water; sea water diluted in deionized water at ratios (v/v) 1: 2, 1: 4, 1: 8; sea water plus 26 gr/l NaCl; deionized water, as control.

The experimental results show that germination is reduced and delayed when seeds are soaked in progressively concentrated salt solutions; in sea water plus 26 gr/l NaCl seed germination is inhibited.

Seeds pretreated by soaking at 3°C for 10 days in sea water diluted (1:1) by deionized water did not show, when soaked in salt solution at weak and middle concentration, any delay in germination in comparison with unpretreated seeds. On the contrary, pretreated and unpretreated seeds sown in sea water at 30°C had shown, 180 days after ripening, a significant depression in germination values as compared with seeds sown at 20°C.     

Osservazioni Morfologiche Ed Anatomiche Sull' Apparato Sotterraneo Della Carlina Acaulis L.

Abstract

Orservation on the morphology and the anatomy on the subterranean organ of CARLINA ACAULIS L. — The morphology and the anatomy of the subterranean organ of Carlina acaulis L. have been studied in relation to the structure of the analogous organ in Atractylis gummifera L. (Maugini, 1960). It has been shown that the two organs differ markedly: in Carlina there is an evident flattening and dissociation of the stem and a dual anatomical structure, related both to stem and to root.     

Effetto Della Colchicina Su Enzimi Solfidrilici

Abstract

The effect of colchicine on sulfhydryl enzymes. — The effect of colchicine has been tested on mithocondrial ATPase and rat-liver LDH. The colchicine inhibits ATPase for 40% and LDH for 100%, therefore its action is aspecific.     

Su La Temperatura Della Pianta Del Gelso (Notizie Preliminari)

Abstract

The purpose of this study was to determine tocopherol (Toc), fatty acid and phytosterol content in dry seeds of nine wild taxa of Sicilian Brassica sect. Brassica. Analyses were performed by gas chromatography (GC)‐mass spectroscopy (MS). The biochemical analysis of dry seeds showed that in the nine taxa examined, α‐ and γ‐Toc were the major isomers, δ‐Toc was present in traces and β‐Toc was never found. All taxa had a similar fatty acid composition with C 16:0 (357.2 mg kg^?1 DW), C 18:1 (393.94 mg kg^?1 DW) and C 22:1 (618.29 mg kg^?1 DW) acids present in higher amount. Unsaturated fatty acids (52.5–66.5%) were more abundant than saturated (33.5–47.5%) ones relative to the total fatty acids. Moreover, sitosterol was the most abundant (61.7–69.6%) of all phytosterols in all species and subspecies, followed by brassicasterol and campesterol at 16.0–19.3% and 11.9–20.7%, respectively. Total Toc content and the relative percentage of single isoforms were useful to discriminate seeds of B. incana, B. macrocarpa, B. rupestris group and B. villosa group. On the basis of these results, B. villosa subsp. villosa, B. villosa subsp. bivoniana, B. villosa subsp. drepanensis and B. villosa subsp. tinei can be ascribed to the B. villosa group. These taxa, having the highest T‐Toc, γ‐Toc and phytosterol contents, are potentially the most bioactive ones, and could, therefore, be exploited in breeding programmes to develop genotypes with putative positive effects on human health.

Abbreviations: B, Brassica; DW, dry weight; FA, fatty acids; RH, relative humidity; T‐FA, total fatty acids; T‐Phy, total phytosterols; T‐Toc, total tocopherol; Toc, tocopherol     

Contributo Allo Studio Sistematico ed Ecologico Della Luzula Calabra Ten. dell'Altipiano Silano

Abstract

Contribution to the systematics and ecology of LUZULA CALABRA Ten. of the Silan highland (Calabria, Southern Italy). — The Luzula calabra Ten. represents a known type endemic to the Silan highland.

Some authors regard it as a species in itself, others include it as a variety in the Luzula campestris Lam. et DC. cycle.

Therefore, in view of the fact that the systematic value of this entity has not yet been well defined and that it is not always easy to succeed in attributing isolated specimens to the Luzula calabra Ten., and all the more because information relating to the environment in wich the plant lives is scant and not always reliable, the intention of this work has been to specify, by biometric analysis, the fundamental characteristic of the Luzula calabra Ten., and furthermore to give and adequate picture of the environment in wich the plant lives.

The resultats of statistical analysis and the diagrams ottained show how the Luzula calabra Ten. offers a particular physiognomy of its own and how it stands out from the others in the Luzula campestris cycle.

The environment in wich the plant completes its life cycle is shown in a series of areas in the Silan marshes, occupied by various vegetal groups folloving one another regularly from the wettest part to the driest wich is populated by the Nardus stricta L. and the Festuca rubra asperifolia St. Yves.

In Sila the presence of two Luzule of the Luzula campestris cycle is identified: the Luzula calabra Ten., wich must be considered almost surely as a species in itself, and the Luzula campestris Lam. et DC. ssp. vulgaris Buchen; on the other hand, the presence of the Luzula campestris Lam. et DC. ssp. multiflora Buchen is thought unlikely, and this is considered to be a form peculiar to high pasture-lands of the strictest alpine-mountain type.     

Sur le développement des spores et la formation du thalle rampant de Kallymenia microphylla J. Ag. (Rhodophyceae,Cryptonemiales)

Abstract

On the spore development and the growth of Kallymenia microphylla J. Ag. (Rhodophyceae, Cryptonemiales) creeping thallus. — The filamentous creeping axis produced by spore grows into a terminal cell and then branches out into a monostratified creeping thallus looking like a disc. This creeping thallus is looking exactly like that of the Rhodocorton haucki (Schiffner) Hamel. Compared to the other species of Kallymenia, we find out that this creeping thallus has cellular fusions as well; they are more frequent and appear quite early here.     

Flora Delle Isole Palmaria e Tino (Golfo Della Spezia)

Abstract

Flora of Palmaria and Tino islands. — Palmaria and Tino are two small islands at the entrance of the Gulf of La Spezia. They are formed of grey fossiliferous limestones of the Rhaetian period and of more recent — but still of the Rhaetian period — dolomitic limestones. Their climate is definitely more mediterranean than that of the La Spezia coasts laying near by; the winters are milder and the annual precipitations much lower (at the Palmaria 525 mm, at La Spezia 1375 mm. The flora is composed of 399 entities and has a biological spectrum in which the Hemicryptophytes predominate (35,33%), however also the Therophytes (29,57%) and the Geophytes (15,03%) are frequent. The test of the floristic composition shows that the eumediterranean elements are predominant (24,56%) but also the submediterranean (12,53%) and the central southern European (13,53%) are frequent; besides, the subatlantic (6,01%) and the Eurasian ones are also to be found (9,27%). From the test of the floristic components of the three floras of Palmaria and Tino, Capo Caccia in north western Sardinia and of the Marettimo island in western Sicily, it has been found that there is a bigger quantity of eumediterranean elements than in the islands near La Spezia (24,56%) at Capo Caccia (42,14%) and at Marettimo (47,60%), and on the contrary a decrease of the central southern European (13,53%, 9,50%, 6,40%). The fact that the island of Sardinia was separated from the continent since very early times is proved by the presence at Capo Caccia of a lower number of euro-centralasiatic plants (6,76%, 3,30%, 6,60% respectively), of sub-Atlantic ones (6,01%, 1,65%, 3,80%), and of Eurasian ones (9,27%, 7,85%, 8,20%) and on the contrary by a higher number of Sardinian-Corsican endemisms at Capo Caccia (8,67%), definitely higher than the ones in Sicily at Marettimo (3,40%) and the Tuscan-Ligurian endemisms at Palmaria and Tino (only 0,75%) islands which are a few dozen meters near the coast, from which they were separated in recent periods. Among the plants of phytogeographycal interest I would like to mention Centaurea cineraria which is present at the Palmaria and Tino with the var. veneris; may be once spread on most of the Mediterranean coasts. Most of the Mediterranean plants growing on the Palmaria and Tino have a distribution area which includes a great part of the Mediterranean. Just a few of them (Cephalaria leucantha, Argyrolobium zanonii, Phagnalon sordidum, Staehelina dubia, Pinus pinaster, Antirrhinum latifolium) are western submediterranean, distributed mostly in Europe; in comparison, at Marettimo there are western eumediterranean plants growing in northern Africa with some remains in the Spanish peninsula. At Marettimo eastern eumediterranean plants also grow, while at Palmaria and Tino are to be found only some plants that, from the north-eastern coasts of the Mediterranean sea, reach the interior of the Balkan peninsula (Genista januensis) or the Pontic region. (Coronilla cretica, Dorycnium pentaphyllum var. berbaceum).     

Rilevamento Cartografico Della Vegetazione Della Conca di Bormio (Valtellina) Presentazione della Carta Fitosociologica all'1:5.000

Abstract

Account on the Cartography of the Vegetation of the Basin of Bormio (Valtellina). Presentation of the phytosociological Map 1:5000. — The authors illustrate the features of the new phytosociological map of the basin of Bormio (Valtellina). The chief types of vegetation of the region are outlined.     

Escursione Floristica Nelle Isole Pelagie

Abstract

Floristic excursion in the Pelagie Islands. — This is the result of the Author's researches in the Pelagie Islands. He points out the geobotanic interest of Limoniastrum monopetalum growing in the island of Linosa, and states that though it is widely present in the Mediterranean world, Limoniastrum monopetalum grows in districts which are very far from one another, so that its area results fragmentary.     

Embryological observations on Helichrysum rupestre (Rafin.) DC. var. errerae (Tineo) Pignatti

Abstract

The ovule and anther development of Helichrysum rupestre var. errerae from Pantelleria is studied. The ovule is anatropous, tenuinucellate, unitegmic, endotheliate and is derived from a two-zonate primordium. The archespore is one- or two-celled and all the megaspores show a functional tendency, although only the chalazal one is able to form the gametophyte according to the Polygonum type. The polar nuclei fuse before fertilization and the three antipodal cells divide further. Anthers are tetrasporangiate and their wall development conforms to the Dicotyledonous type. The epidermis persists at maturity and the endothecial cells thicken their walls. The tapetum is of the periplasmodial type and its cells become plurinucleate during microsporogenesis. The number of microsporocytes varies along the length of the same locule. Arrangement of the resulting microspores is tetrahedral, isobilateral or decussate. Pollen grains are three-celled when shed. Degenerating microsporocytes and microspores have frequently been found.     

Utilizzazione Di Afidi Per Il Prelevamento Della Linfa in « Cuscuta Epithymum »

Abstract

Use of Aphids for sampling the cell sap of Cuscuta epithymum. — A variety of Myzus persicae that feeds specifically on Cuscuta epithymum has been employed in a study of the translocation of nutrilites from the host, Trifolium repens, to the parasite, C. epithymum. If the host was exposed to an atmosphere containing C¹⁴,O₂, the Aphids feeding on the Cuscuta filaments became labelled very rapidly and to considerable extent. The analysis of the distribution of radioactivity in the Cuscuta filaments and the Aphids revealed that extensive degradation of the compounds and randomization of the label occurred in the insects.     

Active coexistence of the novel gammaproteobacterial methanotroph ‘Ca. Methylocalor cossyra’ CH1 and verrucomicrobial methanotrophs in acidic,hot geothermal soil

Terrestrial geothermal ecosystems are hostile habitats, characterized by large emissions of environmentally relevant gases such as CO₂, CH₄, H₂S and H₂. These conditions provide a niche for chemolithoautotrophic microorganisms. Methanotrophs of the phylum Verrucomicrobia, which inhabit these ecosystems, can utilize these gases and grow at pH levels below 1 and temperatures up to 65°C. In contrast, methanotrophs of the phylum Proteobacteria are primarily found in various moderate environments. Previously, novel verrucomicrobial methanotrophs were detected and isolated from the geothermal soil of the Favara Grande on the island of Pantelleria, Italy. The detection of pmoA genes, specific for verrucomicrobial and proteobacterial methanotrophs in this environment, and the partially overlapping pH and temperature growth ranges of these isolates suggest that these distinct phylogenetic groups could coexist in the environment. In this report, we present the isolation and characterization of a thermophilic and acid-tolerant gammaproteobacterial methanotroph (family Methylococcaceae) from the Favara Grande. This isolate grows at pH values ranging from 3.5 to 7.0 and temperatures from 35°C to 55°C, and diazotrophic growth was demonstrated. Its genome contains genes encoding particulate and soluble methane monooxygenases, XoxF- and MxaFI-type methanol dehydrogenases, and all enzymes of the Calvin cycle. For this novel genus and species, we propose the name ‘Candidatus Methylocalor cossyra’ CH1.     

Aspetti Enzimatici Della Maturazione e Germinazione dei Semi di Ricino

Abstract

Enzyme levels during ripening and germination of castor bean seeds. — During the development of the endosperm of castor bean seeds two distinct phases can be recognized: pre-maturation and germination. The former is characterized, metabolically, by the rapid conversion of carbohydrates into lipids, and storage proteins. The latter is characterized by the reconversion of these storage materials into sugars. Both these processes are dependent upon the activity of the glycolytic pathway; for this reason the behaviour of some enzymes of this pathway and, in general, of the carbohydrate metabolism have been studied during the two phases. The changes (during the evolution of the seeds) of the following enzymes have been studied:

Gl-6-P-dehydrogenase, 6-P-gluconate dehydrogenase, P-glucomutase, Hexokinase Hexoseisomerase, Aldolase, alcaline and acid Phosphatase, Pyrophosphatase and ATP-ase.

All these activities have been measured in the 20.000 × g supernatant fraction of cell homogenates.

The results show that all the enzymes activities measured increase rapidly during the period of accumulation of storage materials. In the following period all of these activities decrease until the stage of ripeness of the seed. During the first few days of germination the activities increase again rapidly. A particular behaviour is the one of Fr-1-6-P-phosphatase (the enzyme cleaving the phosphate bond in C ¹ position). This enzyme reaches during germination a level much higher than the maximal observed during the ripening process. This might be an important fact correlated with the inversion of the glycolytic reactions during germination.