Bacteriocin production by members of the genusKlebsiella

Bacteriocin production was tested in 36Klebsiella and 3Enterobacter aerogenes strains. Bacteriocins produced byK. pneumoniae were found to be active on most strains ofK. edwardsi, K. aerogenes, K. rhinoscleromatis andE. aerogenes. The bacteriocin produced byE. aerogenes 37 is also active onK. pneumoniae andK. ozaenae. The bacteriocins produced byK. rhinoscleromatis, K. edwardsi andK. aerogenes are active on only a few strains. The activity spectra of the bacteriocins of a number of strains were similar. The method of classification used for colicins could not be applied to these bacteriocins as mutants resistant to one bacteriocin were nearly always resistant to all other bacteriocins. One mutant, though resistant, still adsorbed the bacteriocin to which it was resistant and it is very likely that the same applies for all other resistant mutants. The hypothesis is made that allKlebsiella bacteriocins have the same biochemical target, or more likely, possess a common transmission mechanism.     

Differentiation of species in Gonioloboceras

The type specimen ofGonioloboceras goniolobum (Meek), rediscovered by Spath in the British Museum, is the foundation for a more accurate comparative study of this and other species ofGonioloboceras.Gonioloboceras described asG. goniolobum byElias in 1938 is differentiated asGonioloboceras schmidti, new species. Suture sets (new term) for several growth stages inG. goniolobum (Meek),G. welleriSmith,G. schmidtiElias, G.eliasiMiller &Owen, andG. asiaticumLibrovitch are assembled and used for differentiation of the species.The Kazakhstan goniatite faunule containingG. asiaticum is considered of very late Pennsylvanian age.     

The origin of the North Indian sugarcanes

The “North Indian sugarcanes”, cultivated by Indian peasants during many centuries, have been studied morphologically very exactly byC. A. Barber from 1910 to 1920. They were named “Saccharum Barberi” byJeswiet. Barber distinguished four groups. In 1931 the present author found the following chromosome numbers in these groups: 2n=116 and 2n=82 in the Sunnabile group; 2n=82 in the Mungo group; 2n=124 and 2n=107 in the Nargori group and about 91 in the Saretha group. The first three groups are sterile, the last is fertile. It is shown that the North Indian sugarcanes are hybrids between ancient indigenous sugar canes with a basic number of 17 chromosomes, and forms ofS. spontaneum withn=40,n=48 andn=56 respectively. Differences in the numbers of chromosomes contributed by the mother type may in part have their origin in endo-duplication, as commonly observed inSaccharum hybrids. Details are presented in Table 2. The differences found between different forms of IndianS. spontaneum in respect to chromosome number, sugar content and mosaic resistance may be attributed to intercrossing with canes of the fertile Saretha group.     

Variation in the spectrum of Fusarium species on winter wheat

In 1998–2000 a monitoring of the spectrum of Fusarium species on winter wheat was carried out in the Rhineland. The epidemic spread ofFusarium spp. on wheat plants during growing season was investigated as well as the grain contamination after harvest.F avenaceum was the Fusarium species isolated most frequently followed byF culmorum, F poae andF graminearum. Microdochium nivale occurred considerably only in 1998. Both, susceptibility and plant height of the cultivars were correlated to the incidence of Fusarium species /M nivale on harvested kernels; interactions with cropping intensities were detected. The incidence ofF poae seemed to be independent of the cultivar-specific Fusarium susceptibility. Despite the lack of disease symptoms, between growth stages 45–85 mycelium ofFusarium spp. was detectable in the leaves as well as conidia on the leaf surfaces.     

Die Arten der Foraminiferen-GattungAsterigerina d'Orb. im Tertiär NW-Deutschlands

Some species ofAsterigerina are described and discerned, as they occur in different levels of the sequence from Eocene to Miocene in northwestern Germany.Asterigerina bartoniana (Dam) in the Eocene is followed byAsterigerina rotula haeringensis Lühr andAsterigerina brandhorstiana n. sp. in the Lower Oligocene (sensuBeyrich).Asterigerina gürichi gürichi (Franke), typical for the lowermost part of sequences of Upper Oligocene age, is furnished with a lectotype out ofFrankes material. This species is substituted by the subspeciesAsterigerina gürichi staeschei (Dam & Reinhold) in the Miocene. The localities of Lower Oligocene in littoral facies near Bünde (Westfalia) are mentioned and described. (Localities “Brandhorst” resp. “Hof Fahrenkamp” and newer outcrops).     

Correlations between the ages of<Emphasis Type="Italic">Alnus</Emphasis> host species and the genetic diversity of associated endosymbiotic<Emphasis Type="Italic">Frankia</Emphasis> strains from nodules

Nodule samples were collected from four alder species:Alnus nepalensis, A. sibirica, A. tinctoria andA. mandshurica growing in different environments on Gaoligong Mountains, Yunnan Province of Southwest China and on Changbai Mountains, Jilin Province of Northeast China. PCR-RFLP analysis of the IGS betweennifD andnifK genes was directly applied to unculturedFrankia strains in the nodules. A total of 21 restriction patterns were obtained. TheFrankia population in the nodules ofA. nepalensis had the highest genetic diversity among all fourFrankia populations; by contrast, the population in the nodules ofA. mandshurica had the lowest degree of divergence; the ones in the nodules ofA. sibirica andA. tinctoria were intermediate. A dendrogram, which was constructed based on the genetic distance between the restriction patterns, indicated thatFrankia strains fromA. sibirica andA. tinctoria had a close genetic relationship.Frankia strains fromA. nepalensis might be the ancestor ofFrankia strains infecting otherAlnus species. From these results and the inference of the ages ofAlnus host species, it is deduced that there was a co-evolution betweenAlnus and its microsymbiontFrankia in China.     

The uptake of inorganic sulphate by a brewer’s yeast

The uptake of³⁵S-labelled inorganic sulphate by a brewer’s yeast has been examined. Optimum uptake by cell suspensions required the presence in the medium of glucose, ammonium ions and citrate. The omission of phosphate produced little or no effect. Ammonium ions could be replaced almost completely byL-glutamine but not by a number of amino acids. After one hour approximately 60% of the sulphate-sulphur accumulated appeared in protein. This was comparable to the rate of entry of methionine-sulphur into yeast protein. Sulphate uptake was inhibited by azide, 2,4-dinitrophenol, iodoacetate and mercuric ions. Arsenate was inhibitory at high concentrations but stimulated uptake at low concentrations. Selenate inhibited uptake competitively and appeared to have an affinity for the sites of uptake comparable with that of sulphate. Uptake was also partly suppressed byL-methionine,L-ethionine,L-cysteine andDL-homocysteine.     

Notes on Bletia (Orchidaceae)

New species ofBletia from Mexico are described and illustrated:B. concolor, B. similis, andB. urbana. The identity ofB. campanulata Llave & Lex. is discussed, andB. reflexa Lindl. is considered to be a distinct species. Several South American epithets are treated as synonyms ofB. campanulata. A key to the recognized species ofBletia is given.     

The parasitism of the mouldPenicillium purpurogenum onAspergillus niger

The causes of the formerly described effect of the limitation of infection of surface citric acid fermentation byPenicillium purpurogenum by the action of an increased air supply have been ascertained. The influence of the increased air supply on the composition ofAspergillus niger mycelium and cell walls was followed, as well as their assailability by the lytic enzyme ofPenicillium purpurogenum. Further the effect of temperature, humidity, oxygen supply and presence of carbon dioxide on the growth of the parasitic mould was evaluated. The main cause of the mentioned effect seems to be the drainage of humidity by increased air supply.     

Genomic modulation of diabetes (<Emphasis Type="Italic">db/db)</Emphasis> and obese (<Emphasis Type="Italic">ob/ob</Emphasis>) mutation-induced hypercytolipidemia: cytochemical basis of female reproductive tract involution

Infertility and hypercytolipidemic utero-ovarian involution are recognized consequences of the diabetes-obesity syndrome (DOS) in C57BL mice with either obese (ob/ob) or diabetes (db/db) single gene mutations. We have evaluated the interdependent deleterious influences of both mutation types and differences in the genomic background on utero-ovarian dysfunction in C57BL mice. Control (+/?) C57BL mice were matched with littermate ob/ob and db/db mutants expressed on either the /KsJ or /6 background. Both ob/ob and db/db mutations increased body weights of /KsJ and /6 background strains relative to +/? groups. In contrast, uterine and ovarian weights were depressed by ob/ob and db/dbmutations relative to +/?, regardless of the background strain, but especially when expressed on the /KsJ background. Functionally, both ob/ob and db/db mutations induced hyperglycemic-hyperinsulinemic states coupled with depressed serum estradiol-17-β and progesterone concentrations when expressed on a /KsJ background. Microscopic analysis of utero-ovarian tissue samples revealed marked hypercytolipidemia in the follicular granulosa and endometrial epithelial tissue layers of both ob/oband db/db mutant groups relative to normal +/? cytoarchitecture. The db/db mutation consistently promoted more severe hypercytolipidemic profiles than the ob/obmutation, regardless of background strain. Thus, the severity of utero-ovarian hypercytolipidemia following the expression ofob/ob and db/db mutations in C57BL mice is influenced, or moderated, by the genomic background on which the mutation is expressed.     

Alternative egg-feeding tactics in <Emphasis Type="Italic">Telmatherina sarasinorum</Emphasis>, a trophic specialist of Lake Matano’s evolving sailfin silversides fish radiation

Feeding specialisation is a typical feature of adaptive animal radiations. Different kinds of feeding specialisations have evolved in the endemic sailfin silversides species flock in Lake Matano (Central Sulawesi, Indonesia), including egg-feeding. The present study focuses on Telmatherina sarasinorum, a sailfin silverside species feeding on the eggs of related Telmatherina antoniae. Stomach content analyses supported T. antoniae eggs to be the dominant food item, independent of daytime. We hypothesized that the egg-feeders use alternative tactics for maximising egg consumption under varying densities of both, spawning T. antoniae pairs and competing conspecific egg-feeders. Focal behavioural observations were applied to describe different feeding tactics and to analyse feeding success and the related costs in terms of competitive interactions. Egg-feeders followed single courting pairs of T. antoniae or, alternatively, they switched between different spawning pairs. Following-behaviour, covering one or more spawning events of the host species, was positively related to enhanced egg consumption. Compared to feeding by switching frequently among different spawning pairs, the following tactic came at the cost of likewise increased competition. Behavioural observations suggest that some males monopolize courting pairs of T. antoniae and gain increased amounts of eggs compared to others avoiding competition by switching among pairs. The present results confirm that egg-feeding is a distinct trophic specialisation in T. sarasinorum and increase the scale of behavioural specialisation in Lake Matano’s evolving Telmatherina radiation.     

A food-web approach to economic thresholds: A sequence of pests/predaceous arthropods on California cotton

The value of an adequate food base for predaceous arthropods as provided byTetranychus is relevant for the development of economic thresholds for this group and also for pests that occur later in the season. A higher predaceous potential was reflected in greater levels ofGeocoris and ofOrius on untreated plants with abundant food, as compared with lower predator numbers on insecticide-treated plants having lower food levels. The higher numbers ofGeocoris andOrius were significant because they persisted through July–August. In the San Joaquin Valley, an increase in predators during this period is highly beneficial, becauseLygus and lepidopterous worms may damage cotton at this time.Policy guidelines on effects from chemicals on arthropods need re-evaluation. The assessment of disruptive effects of chemicals must include their impact on the arthropods that constitute the principal sources of food for predaceous arthropods. The indirect effect of chemicals against beneficial-predaceous insects via disruption of their food chain is highly significant because a considerably longer time-interval is required to replenish the food supply, than is needed for beneficial-predaceous adults to reinvade a field.Results from this study support our contention that at least four components must be considered seasonally in developing economic thresholds for pest management programs: 1) the plants. 2) the complex of key pests, 3) the complex of beneficial arthropods, and 4) sources of food in the form of minor «pests» required to support significant numbers of predaceous arthropods in agricultural crops.     

A nomenclatural analysis of the generic names of phanerogams proposed byF. M. Opiz in his Seznam rostlin květeny české

The authors have examined the nomenclatural status of the generic names proposed byF. M. Opiz in his work “Seznam Rostlin Květeny ?eské” (A list of Bohemian plants) and of names which have been regarded in later literature as first published in that book. Many of the generic names proposed byOpiz in his Seznam were not in fact validly published in that book; on the other hand the valid publication of several names is conditioned by various types of indirect indication of an earlier effectively published diagnosis. Of the 80 generic names analysed 36 were validly published byOpiz in various works (not all in the Seznam), but only 13 to 15 are legitimate in the sense of the International Code 1966. The legitimate names are:Cenekia, Ceranthe, Duschekia, Euacer, Jovibarba, Kablikia, Lamiopsis, Liebichia, Plethiosphace, Pseudolysimachion, Spirocarpus, Swida, Weitenwebera and perhapsMargarospermum andNenningia. Of these legitimate names four are considered by the authors as correct i.e.Duschekia, Jovibarba, Pseudolysimachion andSwida; in the Appendix some new combinations with these generic names are proposed. In the text some mistakes concerningOpiz's generic names in Index Kewensis are corrected. For 14 ofOpiz's generic names the lectotypes are seleced. A special notice is given to the nomenclatural problems of the group “Avenastrum”.     

Sulphur metabolism in Thiorhodaceae. III. Storage and turnover of thiosulphate sulphur inThiocapsa floridana andChromatium species

Thiocapsa floridana strain 1711 andChromatium strains 1211 and 1611 utilize sulphide, thiosulphate, and elementary sulphur as electron donors for growth; sulphite can be used only byChromatium strain 1611. In contrast to the other strains, thiosulphate utilization inChromatium strain 1211 is inducible and not constitutive: thiosulphate is consumed only after an induction period of about 20 hours. The turnover rate of different sulphur compounds is controlled by the CO₂ fixation rate. Using differently labeled³⁵S thiosulphates in short term experiments in a special stirred cuvette, it was shown that the maximum amount of stored intracellular sulphur depends on the strain as well as on the experimental conditions like pH and thiosulphate concentration. WhileChromatium strain 1211 showed a maximum storage of only 10% from sulphane-labeled thiosulphate at pH 6.7, and of 25.7% at pH 6.2,Thiocapsa floridana accumulated 75–90% of the radioactivity into the cells at pH 6.7. While in theChromatium strains the labeling of the cells remained at a constant level until all thiosulphate was consumed, inThiocapsa floridana a defined peak of radioactivity storage was obtained, followed by a steady but 3–4 times slower rate of excretion. With sulphonelabeled thiosulphate no significant accumulation of radioactivity occurred in the cells. During dark-incubation ofThiocapsa floridana (free of intracellular sulphur) in phosphate buffer, pH 6.5, with thiosulphate a production of sulphide could be measured while sulphite was not detected; no sulphide was produced by disrupted cells under the same conditions. The results obtained withThiocapsa floridana strongly support the concept of an initial cleavage of thiosulphate. The present observations do not allow a decision concerning the enzymatic mechanism of the cleavage itself.     

<Emphasis Type="Italic">In vitro</Emphasis> fertilization and preimplantation development in the primate

Nonhuman primates represent a strong model for examining the chromosomal, biochemical, and temporal normality of embryos produced byin vitro fertilization. Morein vitro fertilized embryos from the squirrel monkey(Saimiri sciureus) have been produced and examined than with all other primate species combined. In studies over a 13 year period a fertilization rate approximating 60 % has been developed in this species with 30% of these embryos proceeding to the two cell stage and 50% of these to the three-four cell stage. Chromosomal abnormalities (primarily missing or extra chromosomes) at a level of nine to 16% have been found, a value corresponding to that found inin vivo mating andin vitro fertilization in other species. An incidence of triploidy of 16.7% was observed. RNA and protein synthetic rates appear comparable with those of laboratory species subjected toin vitro fertilization and indicate the initial stages of metabolic activity of the newly formed embryo. Similarly, increases in estrogen incorporation appear after fertilization but no effect is observed in progesterone incorporation. Utilizing 2-deoxy-glucose and insulin, it was determined that the glucose requirement as an energy source for early preimplantationin vitro fertilized primate embryos is very low.Of very great importance is the temporal relationship of the development ofin vitro fertilized squirrel monkey embryos compared with similar development in other primates (including humans) afterin vivo andin vitro fertilization. An analysis of over a decade of work with the squirrel monkey embryos demonstrates a pattern of temporal development that is comparable with all other primate species that have been examined (including the human) and comparable with development afterin vivo fertilization.     

Maranthes (Chrysobalanaceae), a new generic record for America

Maranthes, a genus well known in Africa and Asia, has not been recorded previously in the New World.Couepia panamensis, thought to be endemic to Panama, was found to be synonymous withMaranthes corymbosa, a widespread Asiatic species, and it is reduced into synonymy, making the first American record ofMaranthes. The relationship ofMaranthes toCouepia, and the unusual distribution ofM. corymbosa are discussed.     

Maximizing survivorship in cold: thermogenic profiles of non-hibernating mammals

Winter-active small mammals residing in seasonal environments employ many different behavioral, anatomical and physiological mechanisms to cope with cold. Herein we review research on survival mechanisms in cold employed by small mammals with emphasis on the families Soricidae, Muridae and Sciuridae. The focus of this review is on research delineating the role of seasonal changes in resting metabolic rate (RMR), nonshivering thermogenesis (NST), body mass, and communal nesting in enhancing winter survivorship of six species of small mammals (masked shrewSorex cinereus, short-tailed shrewBlarina brevicauda, southern red-backed voleClethrionomys gapperi, white-footed mousePeromyscus leucopus, deer mouseP. maniculatus, and southern flying squirrelGlaucomys volans) residing in the Appalachian Mountains of Pennsylvania, USA. Each species shows good over-winter survivorship but exhibits a different suite of mechanisms to maximize survival in cold.B. brevicauda, S. cinereus, andG. volans show slight increases in RMR during winter, whereasPeromyscus andC. gapperi exhibit decreased RMR overwinter. All six species experience elevated NST in winter. The comparatively low RMR and NST ofG. volans during winter was attributable to a decreased energy expenditure due to a larger body mass, coupled with communal nesting in cavities of trees that provided insulation from low ambient temperatures. Squirrels nesting singly experienced a longer period of elevated NST in winter and higher mean NST year-round than did squirrels nesting communally. Energy conservation in the form of growth retardation in winter was exhibited byC. gapperi andS. cinereus but not the other species.