Enzymatic enhancement of the free monoterpenol content of a Portuguese wine from a single,native grape variety; “Trajadura”

Summary Three important monoterpene aroma releasing activities contained in an Aspergillus niger preparation were investigated for effects of pH, alcohol, SO₂, temperature and concentration of glucose. Application of the enzyme preparation during microvinification or wine maturation of a Portuguese white wine from Trajadura grapes, increased monoterpene content roughly 2-fold and 3-fold respectively.Abbreviations -L-araf -L-arabinofuranosidase - -L-rhap -L-rhamnopyranosidase - -D-glup -D-glucopyranosidase - pnp p-nitrophenyl     

Variability in the 11S globulin fraction of seed storage proteins ofHelianthus (Asteraceae)

The seed storage globulins from sixHelianthus and four hybrids were studied using mono and bidimensional gel SDS electrophoresis (+ 2 mercaptoethanol). The polypeptide composition of each subunit was determined. Different pairs are specifically expressed according to the species studied. Three typical patterns were discriminated. All the studied species exhibit five subunits: two of them are expressed in all the species (₁₁ and ₂₂). The subunit corresponding to the ₁₁ pair is present inH. petiolaris and in the three populations ofH. annuus studied. The _2b2 pair is common toH. annuus andH. argophyllus. H. petiolaris presents two specific _2a2 and ₄₄ pairs andH. annuus a specific ₃₃ pair. InH. argophyllus _{11 33} or ₄₄ are never observed but are replaced by ₁₃ and ₃₁ pairs. Some globulins, poorly represented, are of forms but present chains of higher molecular weights (in the range 54–56 kDa). Expressing variations in the banding patterns between these species by the use of a similarity index reveals complete identity between the three populations ofH. annuus. Identity between the twoH. petiolaris studied is also observed.H. annuus andH. argophyllus appear to be closer to each other thanH. petiolaris concerning the seed storage globulins.     

Carcinogenic potential and genomic instability of beryllium sulphate in BALB/c‐3T3 cells

Occupational exposure to beryllium (Be) and Be compounds occurs in a wide range of industrial processes. A large number of workers are potentially exposed to this metal during manufacturing and processing, so there is a concern regarding the potential carcinogenic hazard of Be. Studies were performed to determine the carcinogenic potential of beryllium sulfate (BeSO₄) in cultured mammalian cells. BALB/c3T3 cells were treated with varying concentrations of BeSO₄ for 72 h and the transformation frequency was determined after 4 weeks of culturing. Concentrations from 50–200 g BeSO₄/ml, caused a concentrationdependent increase (9–41 fold) in transformation frequency. Nontransformed BALB/c3T3 cells and cells from transformed foci induced by BeSO₄ were injected into both axillary regions of nude mice. All ten Beinduced transformed cell lines injected into nude mice produced fibrosarcomas within 50 days after cell injection. No tumors were found in nude mice receiving nontransformed BALB/c3T3 cells 90 days postinjection. Gene amplification was investigated in Kras, cmyc, cfos, cjun, csis, erbB2 and p53 using differential PCR while random amplified polymorphic DNA fingerprinting was employed to detect genomic instability. Gene amplification was found in Kras and cjun, however no change in gene expression or protein level was observed in any of the genes by Western blotting. Five of the 10 transformed cell lines showed genetic instability using different random primers. In conclusion, these results indicate that BeSO₄ is capable of inducing morphological cell transformation in mammalian cells and that transformed cells induced by BeSO₄ are potentially tumorigenic. Also, cell transformation induced by BeSO₄ may be attributed, in part, to the gene amplification of Kras and cjun and some BeSO₄induced transformed cells possess neoplastic potential resulting from genomic instability.     

Ganglioside-cholera toxin interactions: a binding and lipid monolayer study

Summary On t.l.c. plates ¹²⁵I-cholera toxin binds to a disialoganglioside tentatively identified as GD_lb with about 10 times less capacity than to ganglioside GM₁. Binding of labeled toxin to both gangliosides was abolished in presence of excess amounts of unlabeled B subunit. Ganglioside extracts from human or pig intestinal mucosa showed toxin binding to gangliosides GM₁ and GD_1b. In ganglioside-containing lipid monolayers the penetration of the toxin was independent of the ganglioside binding capacity.Abbreviations GM₂ Gal-NAc14Gal(3-2NeuAc)14G1c1Cer - GM₁ Gal3Ga1-NAc14Gal(32NeuAc)14G1c11Cer - GD_1a NeuAc23Ga113Gal-NAc14Gal(32NeuAc)14G1c11Cer - GD1b Gall3Gal-NAcl4Gal(32NeuAc82NeuAc)14Glc11Cer - GT_1b NeuAc23Ga113Ga1-NAcal4Gal(3-2NeuAc82NeuAc)14G1c11Cer - dpPC 1,2-hexadecanoyl-sn-glycero-3-phosphocholine - dpPE 1,2-hexadecanoyl-sn-glycero-3-phosphoethanolamine     

Plant regeneration via somatic embryogenesis in Styrian pumpkin: cytological and biochemical investigations

Somatic embryo formation was induced from cotyledon explants of Styrian pumpkin (Cucurbita pepo L. subsp. pepo var. styriaca Greb.) by using a solid MS medium supplemented with 16.11M NAA and 4.44M BA or 26.85M NAA and 13.32M BA. The callus proliferation was more efficient on medium supplemented with 26.85M NAA and 13.32M BA. In contrast, the embryogenic response was higher on medium with lower concentrations of growth regulators (16.11M NAA and 4.44M BA). The time needed for embryo induction did not depend on medium composition. Embryos in globular stage were transferred to three different maturation media, containing 2.89M GA₃ in combination with 0.54M NAA, 11.42M IAA and growth regulator-free medium. The germination rate was the highest when embryos were cultured on medium with 11.42M IAA. Plantlets grown on this medium achieved maturity suitable for transplantation into soil within 9 to 10weeks. The regenerated plants were successfully transferred into field and developed fertile flowers and set fruits. Biochemical analysis showed significant lower total glutathione levels among in vitro grown plantlets compared to seedlings grown in soil. When the plantlets were transferred into soil, they reached a normal size within a month and the glutathione concentration was comparable to seed-derived plants at the same developmental stage. Transmission electron microscopy was used to investigate possible differences in the ultrastructure of cells from callus cultures, and leaf cells of regenerated and seed-derived plants. Differences in the ultrastructure were found within chloroplasts which contained only single thylakoids, large starch grains and small plastoglobuli in callus cells in comparison to leaf cells, which possessed a well developed thylakoid system, small starch grains and large plastoglobuli.     

Na,K-ATPase in several tissues of the rat: Tissue-specific expression of subunit mRNAs and enzyme activity

Summary The relative contents of Na,K-ATPase subunit mRNAs in rat renal cortex; ventricular myocardium, skeletal muscle (hind limb), liver and brain (cerebrum) were measured. Expressed per unit DNA, mRNA₁ content was 2-fold greater in the kidney and brain as compared to either heart, skeletal muscle or liver. The hierarchy of mRNA₂ expression was brain > skeletal muscle > heart, whereas mRNA₃ was restricted to brain. Betal subunit mRNA content in both kidney and brain exceeded the abundance of liver mRNA ₁ by 7-fold. In all tissues examined, the combined abundances of the alpha subunit mRNAs exceeded the content of mRNA ₁ The hierarchy of Na,K-ATPase activity expressed per unit. DNA was brain > kidney > skeletal muscle = heart > liver. The sum of mRNA as well as mRNA ₁ content, expressed per g of tissue, was highest in brain and kidney. A statistically significant correlation between mRNA ₁ content and Na,K-ATPase activity was evident.     

The mechanism of object fixation and its relation to spontaneous pattern preferences in Drosophila melanogaster

The orientation behavior of walking flies, Drosophila melanogaster, towards a single 6° wide black vertical stripe (elementary stripe) can be explained by use of the turning tendency function H(). This function is characterized by maximal values at an angular distance of =25° from the stable zero position (=orienting direction), a sharp decline from this maximum to =60°, and a very slow approach to the unstable zero position (Horn and Wehner, 1975). The shape of this function is influenced by both translatory and rotatory components of movement. If the translatory component is minimized by measuring the turning function W() (see 2.3) at a distance of 10 mm (C1) from the center of the arena, a change in the strength of this decline is caused. But with increasing translatory component, i.e. at a greater distance from the center of the arena, W() approximates the heuristical function H() (Fig. 12). The turning functions W() are pattern-specific; the angular positions of the maximum responses shift to greater angles with increasing width of the patterns (Fig. 2). In the twopattern configuration with double or single stripes, there is always a coincidence between the stable zero positions of W (), the mean of the frequency distributions P() of the flies' positions and n _g() of the straight courses, and the stable zero positions of H () obtained from an additive superposition of two or more angular shifted turning tendency functions H() (Fig. 5, 7). Therefore, the mean positions of the flies in a multi-stripe experiment composed of elementary stripes can be predicted from the addition of many angular shifted turning tendency functions H(). Between H() and the frequency distribution P() of the flies' positions , the following formula holds: P() =C·H()d (Fig. 13). With this equation, the spontaneous preference of the broader of two double stripes can be explained presuming lateral interactions between the components of the patterns (Fig. 8, 10). The strength x _i ^* of this lateral interaction depends on the width of the double stripes. The greater , the smaller is x _i ^* . x _i ^* is a pattern-specific value (Table 1, 2).Supported by the Deutsche Forschungsgemeinschaft, Ho 664/2     

An isolated β 1 exon next to the DR α gene in the HLA-D region

A cosmid clone containing the DR gene and a ₁ exon of a DR -related gene was isolated from a human cosmid clone bank made from the consanguineous DR7 cell line MANN. No other DR-related exons were found on this clone. The ₁ exon was located about 15 kb away from the DR gene in a tail-to-tail (3 to 3) orientation. The exon contained several deleterious mutations: a defective splice site at the 5 end, two translational frame shifts (a 1 by deletion and a 1 bp insertion), and three extra cysteine residues. Nucleotide and amino acid sequence comparisons of the ₁ exon indicated that although it is substantially different from other class II -chain genes, it is slightly more related to DR than to any other class 11 gene. The DR-related sequence was on a DNA fragment which showed no polymorphism on a panel of cell lines with Eco RI or Pst 1. These Southern blots, however, revealed a related, polymorphic sequence in the human genome. Nucleotide sequences in the intron flanking the ₁ exon shared greater sequence homology than the ₁ exon itself when compared with the DR genomic sequence. The exon may play a role in the generation of variation in expressed class II -chain genes and it may be a relic of a different subset of class II products.     

Effects of light on nitrate-limited Oscillatoria agardhii in chemostat cultures

The effects of the average light irradiance (I) on growth and nitrate uptake kinetics of the cyanobacterium Oscillatoria agardhii, in nitrate-limited chemostat cultures, were studied. Light was nonsaturating for I <9.4 Wm^–2, for all growth rates () studied. However, was throughout limited by the availability of nitrate. Under light-saturating conditions the kinetics of nitrate-limited growth could be adequately described by both the Monod and Droop equations. Under light-non-saturating conditions the internal nitrogen content (Q) was a function of both and I, for which new formulas were derived. The high uptake capacity (V _max) of nitrate-limited cells was independent of , but was significantly increased for cells growing at I <9.4 Wm^–2. The half-saturation constant for nitrate uptake (K _s ^u ) increased with increasing , but was independent of the prevailing light conditions. The effects of light during nitrate-limited growth were associated with the regulation in the nitrogen-containing pigments.The results reported herein have important consequences for the use of Q, K _s ^u and V _max values as indicators of nutrient-deficiency of natural populations.     

Detection of the gangliosideN-glycolyl-neuraminyl-lactosyl-ceramide by biotinylatedEscherichia coli K99 lectin

K99 lectin fromEscherichia coli was purified and biotinylated via its carboxyl groups using biocytin hydrazide and a water soluble carbodiimide. Biotinylation of two out of the nine carboxyl groups was sufficient to permit detection of the lectin by avidin and did not cause any loss of the haemagglutinating activity. It was demonstrated that the biotinylated K99 lectin retained other important properties of native K99 and that it will probably become a very sensitive detecting reagent. Indeed, it was able to bind to HeLa cells, as do intact bacteria carrying K99 fimbriae, and also to recognizeN-glycolyl-neuraminyl-lactosyl-ceramide in an overlay binding assay. Abbreviations: NeuAc,N-acetylneuraminic acid; NeuGc,N-glycolylneuraminic acid; PBS, phosphate buffered saline (0.9% NaCl containing 150mm sodium phosphate, pH 7.2); LPS, lipopolysaccharide; BCHZ, biocytin hydrazide; EDC, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide; BSA, bovine serum albumin; SDS-PAGE, sodium dodecyl sulfate-polyacrylamide gel electrophoresis; DMEM, Dulbecco's modified Eagle medium. For the gangliosides, trivial names and structures are given according to the recommendations in [43]. NeuAc2-3Gal1-4Glc1-1Cer (NeuAc-GM₃); NeuGc2-3Gal1-4Glc1-1Cer (NeuGc-GM₃); GalNAc1-4(NeuAc2-3)Gal1-4Glc1-1Cer (GM₂); NeuAc2-8NeuAc2-3Gal1-4Glc1-1Cer (GD3); Gal1-3GalNAc1-4(NeuAc2-3)Gal1-4Glc1-1Cer (GM₁); NeuAc2-3Gal1-3GalNAc1-4(NeuAc2-3)Gal1-4Glc1-1Cer (GD_1a); Gal1-3GalNAc1-4(NeuAc2-8NeuAc2-3)Gal1-4Gle1-1Cer (GD_1b); NeuAc2-3Gal1-3GalNAc1-4(NeuAc2-8NeuAc2-3) Gal1.-4Glc1-1Cer (GT_1b). NeuGc2-3Gal1-4GleNAc1-4Gal1-4Glc1-1Cer (NeuGc-SPG).     

Effects of supplied cinnamic acids and biosynthetic intermediates on the anthocyanins accumulated by wild carrot suspension cultures

Anthocyanins isolated and characterized from the wild carrot suspension cultures used here were 3-O--D-glucopyranosyl-(16)-[-D-xylopyranosyl-(12)-]-D<-galactopyranosylcyanidin (1), 3-O-[-D- xylopyranosyl-(12)--D-galactopyranosyl]cyanidin (2), 3-O-(6-O-sinapoyl)--D-glucopyranosyl-(16)-[-D- xylopyranosyl-(12)-]-D-galactopyranos ylcyanidin (3), 3-O-(6-O-feruoyl)--D-glucopyranosyl-(16)-[- D-xylopyranosyl-(12)-]-D-galactopyranosylcyanidin (4), 3-O-(6-O-coumaroyl)--D-glucopyranosyl-(16)- [-D-xylopyranosyl-(12)-]-D-galactopyrano sylcyanidin (5), 3-O-[6-O-(3,4,5-trimethoxycinnamoyl)]-- D-glucopyranosyl-(16)-[-D-xylopyranosyl-(12)-]-D-galactopyranosylcyanidin (6), 3-O-[6-O-(3,4-dime- thoxycinnamoyl)]--D-glucopyranosyl-(16)-[-D-xylopyranosyl-(12)-]-D-galactopyranosylcyanidin (7), 3-O-[(6-O-sinapoyl)--D-glucopyranosyl-(16)--D-galactopyranosyl]cyanidin (8), and 3-O-(-D-galactopyranosyl)cyanidin (9). Except when cinnamic acids were provided in the culture medium, the major anthocyanin present in the two clones examined was 2. When the naturally occurring and some non-naturally occurring cinnamic acids were provided individually in the medium, 1 and 2 were minor components and the anthocyanin acylated with the supplied cinnamic acid, namely 3, 4, 5, 6, or 7 was the major anthocyanin present in the tissue. When caffeic acid was provided the major anthocyanin in the tissue was 4, thereby suggesting that the caffeic acid was methylated before its use in anthocyanin biosynthesis. Other cinnamic acids supplied had limited effects on the anthocyanins accumulated and appeared not to result in the accumulation of new anthocyanins by the tissue. Thus the tissue can use some but not all analogues of sinapic acid to acylate anthocyanins. Additional anthocyanins were detected in extracts of the wild carrot tissue cultures using mass spectrometry (both MS/MS and HPLC/MS). The additional compounds detected have also been found in cultures of black carrot, an Afghan cultivar of Daucus carota ssp. sativa and the flowers of wild carrot giving no evidence for qualitative differences in the anthocyanins synthesized by subspecies, cell cultures from subspecies, or clones from cell cultures. There are major differences in the amounts of individual anthocyanins found in cultures from different subspecies and in different clones from cell cultures. Here anthocyanins without acyl groups were usually found in the tissues and their accumulation is discussed. On the basis of the structures of the isolated anthocyanins, a likely pathway from cyanidin to the accumulated anthocyanins is proposed and discussed.Abbreviations Sin sinapoyl - Fer feruoyl - 4-Coum. 4-coumaroyl - 3,4-MeO₂Cin 3,4-dimethoxyeinnamoyl - 3,4,5-MeO₃Cin 3,4,5-trimethoxycinnamoyl - Cya cyanidin     

Expression pattern of voltage-dependent calcium channel α1 and β subunits in adrenal gland of N-type Ca2+ channel α1B subunit gene-deficient mice

The Ca²⁺ channel _1B subunit is a pore-forming component capable of generating N-type Ca²⁺ channel activity. Although N-type Ca²⁺ channel plays a role in a variety of neuronal functions, _1B-deficient mice exhibit normal life span without apparent abnormalities of behavior, histology or plasma norepinephrine level, presumably owing to compensation by some other Ca²⁺ channel ₁ or subunit. In this study, we studied the levels of _1A, _1C, _1D, _1E, ₁, ₂, ₃ and ₄ mRNAs in adrenal gland of _1B-deficient mice. The _1A mRNA in homozygous mice was expressed at higher level than in wild or heterozygous mice, but no difference in the expression levels of _1C, _1D, _1E, ₁, ₂, ₃ and ₄ was found among wild, heterozygous and homozygous mice. The protein level of _1A in homozygous mice was also expressed at higher level than in wild or heterozygous mice. To examine whether increased expression is induced by cis-regulatory element within 5-upstream region of _1A gene, we examined lacZ expression in _1B-deficient × _1A6.3-lacZ mice (carrying a 6.3-kb 5-upstream fragment of _1A gene fused to E. coli lacZ reporter gene), which express lacZ in medullar chromaffin cells, but not in cortex. The levels of lacZ expression in homozygous _1B-deficient × _1A6.3-lacZ mice were higher than in wild or heterozygous mice. Therefore, a possible explanation of the normal behavior and plasma norepinephrine level of _1B-deficient mice is that compensation by _1A subunit occurs and that 6.3-kb 5-upstream region of _1A gene contains enhancer cis-element(s) for compensation in adrenal medulla chromaffin cells. (Mol Cell Biochem 271: 91–99, 2005)     

Partial mispairing and crossing-over between β0 and δ genes as the origin of the δ β0 thalassemia gene

Summary Two double heterozygous ⁰/⁰ thalassemic sibs of Mexican descent were studied. The father had a ⁰/⁰ genotype, while the mother, one sib and several maternal relatives were ⁰/⁰ heterozygotes. Parental consanguinity and an apparently low frequency of thalassemia among Mexicans suggested a possible common origin of both ⁰ and ⁰ genes. A hypothesis to explain such a possibility is proposed on the basis of a partial mispairing between ⁰ and genes followed by a crossing-over which would results in a ⁰ recombinant gene. This hypothesis could also be extended to explain the 22 gluala, 22 alaglu and 116 arghis Hb variants as recombinants from double crossing-over between and mispaired genes for which the name interstitial-Lepore is proposed.     

Distance-constraint approach to protein folding. I. Statistical analysis of protein conformations in terms of distances between residues

A statistical analysis of protein conformations in terms of the distance between residues, represented by their C atoms, is presented. We consider four factors that contribute to the determination of the distanced _i,i+k between a given pair ofith and(i+k)th residues in the native conformation of a globular protein: (1) the distancek along the chain, (2) the size of the protein, (3) the conformational states of theith to(i+k)th residues, and (4) the amino acid types of the and(i+k)th residues. In order to account for the dependence on the distancek along the chain, the statistics are taken for three ranges, viz., short, medium, and long ranges (k8; 9k20; andk21; respectively). In the statistics of short-range distances, a mean distanceD _k and its standard deviationS _k are calculated for each value ofk, with and without taking into account the conformational states of all residues fromi toi+k (factors 1 and 3). As an Appendix, the relations for converting from the distances between residues into other conformational parameters are discussed. In the statistics of long-range distances, a reduced distanced* _ij (the actual distance divided by the radius of gyration) is used to scale the data so that they become independent of protein size, and then a mean reduced distanceD _l (a, a) and its standard deviation _l (a, a) are calculated for each amino acid pair (a, a) (factors 2 and 4). The effect of the neighboring residues along the chain on the value of the distanced* _ij is explored by a linear regression analysis between the actual reduced distanced* _ij and the mean value over theD _l for all possible pairs of residues in the two segments of the (i–2)th to the (i+2)th and the (j–2)th to the (j+2)th residues. The effect is assessed in terms of the tangentA _l (a, a) of the calculated regression line for each amino acid pair (a, a). In the statistics of medium-range distances, only factors 1 and 4 are considered, to simplify the analysis. The scaled distanced _i,i+k =(d _i,i+k -D _k )/S _k is used to eliminate the dependence onk, the distance along the chain. The propertiesD _m (a, a), _m (a, a) andA _m (a, a) corresponding toD _l (a, a), _l (a, a), andA _l (a, a), and also calculated for each amino acid pair (a, a). The results are interpreted as follows: the smaller values ofD _l (a, a) andD _m (a, a) indicate a preference of the pair (a, a) for a contact (e.g., pairs between hydrophobic amino acids, and pairs of Cys with aromatic amino acids), and the larger values of these quantities indicate a preference for distant mutual location (e.g., pairs between strong hydrophilic amino acids); the smaller values of _l (a, a) and _m (a, a) indicate a strong preference for either contact or noncontact (e.g., pairs between hydrophobic amino acids, and pairs between strong hydrophobic and hydrophilic amino acids, respectively), and the larger values of these quantities indicate the ambivalent/neutral nature of the preference for contact and noncontact (e.g., pairs containing Ser or Thr); the smaller values ofA _l (a, a) andA _m (a, a) indicate that the distance of an (a, a) pair is determined independently of the amino acid character of the neighboring residues along the chain (e.g., some pairs of Cys or Met with other amino acids) and the larger values of these quantities indicare that such amino acid character contributes strongly to the determination of the distance (e.g., pairs containing Ser or Thr, and pairs between amino acids with small side chains). The difference between the statistics for the long- and medium-range distances is also discussed; the former reflect the difference between the hydrophobic and hydrophilic character of the residues, but the latter cannot be easily interpretable only in terms of hydrophobicity and hydrophilicity. The data analyzed here are used in the optimization of an object function to compute protein conformation in a subsequent paper.     

Production of xylanases by immobilized Aspergillus sp. using lignocellulosic waste

In shake flasks immobilized Aspergillus terreus and Aspergillus niger produced 29IU/ml, 26.7IU/ml xylanases at 10mg/ml, 14mg/ml wheat bran concentration after 48 and 60h of incubation at 37°C respectively. In repeated batch fermentation of immobilized Aspergillus sp. the same biocatalyst could be used for three successive cycles.     

Consequences of harvesting for genetic diversity in American ginseng (<Emphasis Type="Italic">Panax quinquefolius</Emphasis> L.): a simulation study

American ginseng, Panax quinquefolius L., is one of the most heavily traded medicinal plants in North America. The effect of harvest on genetic diversity in ginseng was measured with a single generation culling simulation program. Culling scenarios included random harvest at varying levels, legal limit random harvest and legal limit mature plant harvest. The legal limit was determined by the proportion of legally harvestable plants per population (% mature plants per population). Random harvest at varying levels resulted in significant loss of genetic diversity, especially allelic richness. Relative to initial levels, average within-population genetic diversity (H _e) was significantly lower when plants were culled randomly at the legal limit (Mann–Whitney U=430, p<0.001) or when only mature plants were culled (Mann–Whitney U=394, p<0.01). Within-population genetic diversity was significantly higher with legal limit mature plant harvest (H _e=0.068) than when plants were culled randomly at the legal limit (H _e=0.064; U=202, p<0.01). Based on these simulations of harvest over one generation, we recommend that harvesting fewer than the proportion of mature plants could reduce the negative genetic effects of harvest on ginseng populations.     

The effect of antibiotics on the inhibition of callus induction and plant regeneration from cotyledons of sugarbeet (Beta vulgaris L.)

Callus induction and plantlet regeneration from cotyledonary expiants of sugarbeet was observed utilizing two media formulations, MS and a modified MS termed RVIM both supplemented with 1.0 g/ml BAP as the sole growth regulator. Callus induction was genotype dependent The USDA line 8787 produced the highest response for callus induction followed by Betaseed 4587 and the USDA line C600. This order was conserved on both media formulations. Shoot induction was consistently higher averaging 32% from the RVIM formulation over the 3 genotypes compared to 25% from MS. The antibiotics geneticin, gentamycin, hygromycin, kanamycin and phleomycin were screened with the modified RV system utilizing Betaseed 4587. Callus growth was inhibited by levels of 50 g/ml geneticin, 150 g/ml gentamycin, 10 g/ml hygromycin, 150 g/ml kanamycin and 20 g/ml phleomycin. The results indicate that the concentrations of antibiotics used to inhibit callus induction will be sufficient for use as selectable markers in transformation experiments with Beta vulgaris.Abbreviations B₅ basal medium (Gamborg et al, 1968) - BAP N⁶-Benzylaminopurine - IBA Indole-3-butanoic acid - MS basal medium (Murashige and Skoog 1968) - RVIM modified MS basal medium (Freytag et al, 1988) - MES (2[N-Morpholino] ethanesulfonic acid     

Toxic responses of germinating pollen and soybeans to aflatoxins

Aflatoxin producing strains of Aspergillus grow on soybeans thereby contaminating the latter through secretion of the toxin. Investigations dealing with either soybean seed germination or intact seedling growth responses to aflatoxin (B₁) are lacking. Similarly, a possible interaction of aflatoxins with phosphate in the germination and elongation of both soybeans and pollen as well as roots of the former and tubes of the latter has not been examined. Imbibition of Glycine max, cv. Essex seeds for 18 hours in solutions containing 0.38, 2.90, 5.80 or 11.60 g/ml (AFB₁) yielded% germination inhibitions of 5, 20, 40 and 80, respectively. By 36 hours these were 6, 4, 13 and 19 % for the same toxin concentration series. At 140 hours attached root elongation was inhibited 26, 35 and 50 % for 2.90, 5.80 and 11.60 g/ml AFB₁. No effect was noted at 0.38 g/ml AFB₁. Incubation of excised roots in medium containing 3.0 mM KH₂PO₄ stimulated their elongation 3.2 fold. Addition of 33.28 g/ml mixed aflatoxins together with KH₂PO₄ resulted in only a 1.5 fold stimulation. When KH₂PO₄ was added to a culture medium lacking AFB₁, Lilium longiflorum, cv. Ace pollen germination was enhanced 50%. Withholding KH₂PO₂ but supplying AFB₁ did not markedly affect germination. However, supplementing the medium with KH₂PO₄ while simultaneously adding AFB₁ did not inhibit germination at 5 and 10 g/ml but caused 27.3 and 45.1 % declines at 25 and 30 g/ml. In the absence of KH₂PO₄ AFB₁ stimulated pollen tube elongation 7.5, 14.3, 16.5 and 13.2 % at 5, 10, 15 and 20 g/ml but 30 g/ml inhibited it 11.1%. In contrast, tube elongation was suppressed at all AFB₁ concentrations (maximum 36.1% at 30 g/ml) tested upon KH₂PO₄ addition. Results derived from germinating pollen in medium supplemented with KH₂PO₄ or NaH₂PO₄ indicate that the phosphate anion does not preferentially promote aflatoxin-induced inhibition of tube elongation.Aided by grant IN-127 from the American Cancer Society to W.V. Dashek and funds from the Departments of Biology, West Virginia University and Virginia Commonwealth University and the West Virginia University Foundation.     

Enhanced acetyl esterase production by Fusarium oxysporum

Production of acetyl esterase (EC 3.1.1.6) by Fusarium oxysporum strain F3 was enhanced by optimization of growth conditions. Under optimal conditions, activities as high as 0.89U/ml of culture medium were obtained. The culture filtrate was equally active on p-nitrophenyl acetate and acetylxylan. The enzyme produced 71% deacetylation of acetylxylan in 2h at 40C. Activity was optimized at pH6.5 and at 55^C. The respective K_m values for p-nitrophenyl acetate and acetylxylan were 0.25mM and 1.05% (w/v) and the V_m values were 0.65 and 0.43mol acetate/min/mg protein.