Phylogenetic significance of the skin of New World monkeys (order primates, infraorder Platyrrhini).

The combined properties of a given cutaneous system, like other characters classically employed by systematic zoologists, are useful criteria in the assessment of primate taxonomy and phylogeny. From the synthesis of all available data, it is also concluded that (1) the results define a baseline regarding the normal histology and histochemistry of the skin of most genera and many species of New World monkeys; (2) intrageneric and intraspecific subtleties in cutaneous variation exist in primate integument; (3) single and multiple cutaneous traits contribute to the characterization and accurate identification of most levels of taxa within the primate hierarchy; (4) some traits, however, negate recent taxonomic practices, e.g., the familial position of Callimico; (5) basic cutaneous patterns confirm currently accepted concepts of taxonomy and phylogeny; and (6) the various cutaneous signatures of extant platyrrhines record a history of adaptive radiation in isolation, and suggest that the designation of at least two distinct families is warranted.     

Homoserine and diaminobutyric acid in the mucopeptide-precursor-nucleotides and cell walls of some plant-pathogenic corynebacteria

The nucleotide precursors of cell-wall mucopeptide were prepared by vancomycin inhibition of Corynebacterium insidiosum and Corynebacterium poinsettiae. The amino acid in the third position in the former peptide was shown by optical rotatory dispersion of the bisdinitrophenyl derivative to be l-diaminobutyric acid. Homoserine in the nucleotide from C. poinsettiae was catalytically oxidized to aspartic acid, which was then shown to be the l-isomer by optical rotatory dispersion of the trinitrophenyl compound. The sequence for C. insidiosum was UDP-N-acetylmuramyl-glycyl-isoglutamyl- (gamma-acetyl)-diaminobutyryl-alanyl-alanine. The cell walls of C. insidiosum and Corynebacterium sepedonicum contained diaminobutyric acid that was optically inactive. It is proposed, therefore, that the primary peptide chain contains the l-isomer with its gamma-amino group blocked by acetylation and that cross-linking is achieved by means of the d-isomer, analogous to d-ornithine in C. poinsettiae.     

Physicochemical properties of vancomycin and iodovancomycin and their complexes with diacetyl-l-lysyl-d-alanyl-d-alanine

Electrometric and spectrophotometric titrations showed vancomycin to contain groups having pK values of about 2.9, 7.2, 8.6, 9.6, 10.5 and 11.7. Of these the four last-named were phenolic. Titration above pH11 and below pH1 was irreversible and antibiotic potency was destroyed. Combination with the specific peptide diacetyl-l-lysyl-d-alanyl-d-alanine hindered the titration of the first three phenolic groups. Spectrophotometric titration of iodovancomycin showed that the phenolic group with pK 9.6 was the one iodinated. The stability of the vancomycin–peptide complex in the range pH1–13 showed that complex-formation occurred only when carboxyl groups were ionized and the phenolic groups were non-ionized. The complex was formed in concentrations of urea up to 8m, of potassium chloride up to 4m, of sodium dodecyl sulphate up to 1%, and at temperatures up to 60°C. From titration curves, organic chlorine and iodine analysis, and combination with peptide, a minimum molecular weight for vancomycin of 1700–1800 was estimated. Optical-rotatory-dispersion and circular-dichroism experiments suggested that vancomycin has only limited conformational flexibility. Both vancomycin and its complexes with peptide exhibited properties suggesting aggregation. Vancomycin and iodovancomycin can be fractionated into a main fraction and at least three minor components. The isolation of these fractions salt-free is described and their antibiotic properties are shown to correlate with their ability to form complexes with peptide.     

The configuration of 2,6-diamino-3-hydroxypimelic acid in microbial cell walls

beta-Hydroxydiaminopimelic acid, together with some diaminopimelic acid, occurs in the cell-wall mucopeptide of certain Actinomycetales. These components were converted into their di-DNP derivatives and separated by chromatography. Hence the relative proportions present in the cell walls of a number of species were measured. The problem of acid-induced inversion of configuration was studied. Of the diaminohydroxypimelic acids isomer B (see Scheme 2; amino groups meso, hydroxy group threo to its neighbouring amino group) always predominated but a small proportion of isomer D (amino groups l, hydroxy group erythro) also occurred. The configuration of the diaminohydroxypimelic acids was determined by periodate oxidation to glutamic gamma-semialdehyde, which underwent spontaneous ring-closure. Reduction with sodium borohydride produced optically active proline, the configuration of which was determined by direct measurement of the optical rotation of DNP-proline. Un-cross-linked diaminohydroxypimelic acid in the cell wall was oxidized with periodate in the presence of ammonia. Since the remaining amino group was bound in peptide linkage, ring-closure was prevented and borohydride reduction of the aldehyde-ammonia presumed to be present resulted in the formation of ornithine. The quantity of ornithine was used as a measure of the degree of cross-linking.     

Impact of Coal-Coking Effluent on Sediment Microbial Communities: a Multivariate Approach

The functional response to and recovery from coal-coking waste effluent was evaluated for sediment microbial communities. Twenty estimates of microbial population density, biomass, and activity were measured five times during a 15-month period. Significant effects on microbial communities were observed in response to both wastewater contamination and diversion of the wastewater. Multivariate analysis of variance and discriminant analysis indicated that accurate differentiation between uncontaminated and contaminated sediments required a minimum of nine estimates of community response. Total viable population density, ATP, alkaline phosphatase, naphthalene, and phenanthrene mineralization rates were found to be highly weighted variables in site discrimination. Lipid and glucose mineralization, nitrogen fixation, and sediment protein also contributed significantly to explaining variation among sites. Estimates of anaerobic population densities and rates of methane production contributed little to discrimination among sites in the environment examined. In general, total viable population density, ATP, and alkaline phosphatase activity were significantly depressed in contaminated sediments. However, after removal of this contamination, the previously affected sites demonstrated greater temporal variability but a closer approximation of the mean response at the control site. Naphthalene and phenanthrene mineralization did not follow the general trend and were elevated at the contaminated sites throughout the investigation. Results of the investigation supported the hypothesis that multiple functional measures of microbial community response are required to evaluate the effect of and recovery from environmental contamination. In addition, when long-term effects are evaluated, select physiological traits, i.e., polyaromatic hydrocarbon mineralization, may not reflect population and biomass estimates of community response.     

POLLINATION SYSTEMS IN PASPALUM DILATATUM POIR. (POACEAE): AN EXAMPLE OF INSECT POLLINATION IN A TEMPERATE GRASS

The pollination of Paspalum dilatatum was studied in south-central Oklahoma during the summer of 1979. Pollen was liberated between 0700–0900 hr except on humid mornings (RH ≤ 80%), when there was a delay of 2–3 hr and a reduction in the total air-borne pollen concentration. A rapid decrease in air-borne pollen concentration with distance from the source results from: 1) individual pollen grains larger (50–70 μ in diam) than typical wind-pollinated plants, and 2) some pollen dispersed as clusters of grains. Several floral characters of P. dilatatum led to a hypothesis that this perennial grass may be entomophilous as well as anemophilous. Not only were the pollen grains larger than most other wind-pollinated taxa but the species produced fewer than 2,500 pollen grains per ovule. Three additional observations corroborate this view: 1) solitary bees (Halictidae) actively collect pollen during the morning, 2) the number of pollen grains per stigma was significantly (P < 0.001) greater on racemes exposed to both wind and bees than on racemes exposed only to wind, and 3) the combination of bees and wind as pollinators significantly (P < 0.001) increased seed set compared to wind alone.