A new species of Lupinus (Fabaceae: Lupininae) from southeastern Brazil

Lupinus rubriflorus Planchuelo, from Rio Grande do Sul, Brazil, is described and illustrated. This species is related toL. bracteolaris s.l. differing in pubescence, stipules, and floral characters.     

Enzymatic Preparation of Mono- and Di-Stearin by Glycerolysis of Ethyl Stearate and Direct Esterification of Glycerol in the Presence of a Lipase from Candida Antarctica (Novozym 435)

Mixtures of 1(3)-monostearin and distearin were prepared by direct esterification of glycerol with stearic acid or transesterification using ethyl stearate as acyl donor in the presence of Candida antarctica lipase (Novozym 435) using a variety of solvents of differing polarity. In all cases, the transesterification resulted in higher product yields. In n-heptane as reaction medium the addition of water (3%) was essential for high product yields, with mono- and distearin being produced in almost equal amounts. Using more polar solvents as reaction media, such as acetonitrile or acetone, again the highest yields were obtained in the transesterification mode; employing these solvents the reactions were much more selective towards the formation of monostearin.     

Advantages and limitations in the use of hairy root cultures for the production of tropane alkaloids: Use of anti-auxins in the maintenance of normal root morphology

Summary Brugmansia candida hairy roots, obtained by infection withAgrobacterium rhizogenes LBA 9402, exhibit, after subculturing in liquid media, a tendency towards dedifferentiation. It has been found that the following strategies can be applied to inhibit this dedifferentiation and preserve normal root morphology: (a) lowering both the mineral and sucrose concentration in the media employed so as to diminish osmotic stress (a condition to which these roots appear to be particularly susceptible); (b) employing antiauxins in appropriate concentrations; and (c) maintaining the hairy roots on solid media prior to use in production processes in liquid media. The first strategy suggested does not favor alkaloid productivity, but in this case a two-step method could be attempted: biomass with normal root morphology could be obtained in a first stage using low sucrose concentrations, and in a second stage, sucrose could be increased in order to achieve higher productivity. In all the clones ofB. candida obtained, alkaloid production was biased towards scopolamine.     

An Immunological Assay for Detection and Enumeration of Thermophilic Biomining Microorganisms

A specific, fast, and sensitive nonradioactive immunobinding assay for the detection and enumeration of the moderate thermophile Thiobacillus caldus and the thermophilic archaeon Sulfolobus acidocaldarius was developed. It employs enhanced chemiluminescence or peroxidase-conjugated immunoglobulins in a dot or slot blotting system and is very convenient for monitoring thermophilic bioleaching microorganisms in effluents from industrial bioleaching processes.     

Vanadium compounds

The direct effect of different vanadium compounds upon alkaline phosphatase (ALP) activity was investigated. Vanadate and vanadyl inhibited both the soluble and particulate ALP activity from UMR.106 cells and from bovine intestinal ALP. We have also shown the inhibition of ALP activity in the soluble fraction of osteoblasts by peroxo and hydroperoxo vanadium compounds. ALP activity in the particulate fraction was not inhibited by these species; nor was the bovine intestinal ALP. Using inhibitors of Tyr-phosphatase (PTPases), the soluble ALP was partially characterized as a PTPase. The major activity in the particulate fraction represents the bone-specific ALP-activity. This study demonstrates that different forms of vanadium are direct inhibitors of ALP activity. This effect is dependent on the enzymatic activity investigated and on the origin of the ALP.     

Larval development of three blenniid species Aidablennius sphynx, Coryphoblennius galerita and Lipophrys canevai (Pisces: Blenniidae: Blenniini) in the western Mediterranean

The early stages of development of three blenniid species, Aidablennius sphynx (6.7–15.8 mm BL), Coryphoblennius galerita (4.3–13.9mm BL), and Lipophrys canevai (3.5–10.4 mm BL) are described from specimens collected in the western Mediterranean. The characteristics used for identification included meristic, developmental, morphological and pigmentation characters. Distinguishing characters of these species useful in differentiating them from other species of blenniids for which early stages are known in the Mediterranean are presented. Information on the occurrence of larvae and juveniles of these species off the Catalan coast (north-western Mediterranean) is also given.     

Interactions between nitrate and ammonium during uptake by carob seedlings and the effect of the form of earlier nitrogen nutrition

Seedlings of carob ( Ceratonia siliqua L. cv. Mulata) were used in two sets of experiments in order to evaluate; (1) the reciprocal effects of each nitrogen form on net uptake of nitrate and ammonium, and (2) the effect of earlier nitrogen nutrition on ammonium versus nitrate uptake. In the former group of experiments we studied the kinetics of nitrate and ammonium uptake as well as the interference of each of the two forms with net uptake of ammonium and nitrate by both nitrogen depleted and nitrogen fed carob seedlings. On the whole, nitrogen depletion led to increase in both affinity and V_max of the system for both forms of nitrogen, at the same time as the effects of nitrate on uptake of ammonium and vice versa were concentration dependent. In the second group of experiments the effects of earlier nitrogen nutrition on nitrate and ammonium uptake were characterized, and in this case we observed that: (a) if only one form of N was supplied, ammonium was taken up in greater amounts than nitrate; (b) the presence of ammonium enhanced nitrate uptake; (c) ammonium uptake was inhibited by nitrate; (d) there was a significant effect of the earlier nitrogen nutrition on the response of the plants to a different nitrogen source. The latter was evident mainly as regards ammonium uptake by plants grown in ammonium nitrate. The interactions between nitrate and ammonium uptake systems are discussed on the basis of the adaptation to the nitrogen source during early growth.