<Emphasis Type="Italic">Irpex lacteus</Emphasis>, a white-rot fungus with biotechnological potential — <Emphasis Type="Italic">review</Emphasis>

White-rot fungi that are efficient lignin degraders responsible for its turnover in nature have appeared twice in the center of biotechnological research — first, when the lignin degradation process started being systematically investigated and major enzyme activities and mechanisms involved were described, and second, when the huge remediation potential of these organisms was established. Originally, Phanerochaete chrysosporium became a model organism, characterized by a secondary metabolism regulatory pattern triggered by nutrient (mostly nitrogen) limitation. Last decade brought evidence of more varied regulatory patterns in white-rot fungi when ligninolytic enzymes were also abundantly synthesized under conditions of nitrogen sufficiency. Gradually, research was focused on other species, among them Irpex lacteus showing a remarkable pollutant toxicity resistance and biodegradation efficiency. Systematic research has built up knowledge of biochemistry and biotechnological applicability of this fungus, stressing the need to critically summarize and estimate these scattered data. The review attempts to evaluate the information on I. lacteus focusing on various enzyme activities and bioremediation of organopollutants in water and soil environments, with the aim of mediating this knowledge to a broader microbiological audience.     

<Emphasis Type="Italic">Marcetia candolleana</Emphasis> (<Emphasis Type="Italic">Melastomeae</Emphasis> – <Emphasis Type="Italic">Melastomataceae</Emphasis>), a new species from Bahia (Brazil)

Summary   Marcetia candolleana A. K. A. Santos & A. B. Martins, is apparently restricted to Mucugê, Bahia (Brazil), where it occurs in areas of campo rupestre vegetation. This new species is closely related to the sympatric M. mucugensis Wurdack, but can be easily recognised by its semi-prostate to procumbent habit, reddish glandular-hirsute indument, loose and flexuous branches, leaves with inconspicuous reticulation on the abaxial surface, connectives very shortly prolonged below the thecae, style curved towards the apex, not exceeding the anthers, and pendulous fruit.

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Resumo   Marcetia candolleana A. K. A. Santos & A. B. Martins, é aparentemente restrita a Mucugê, Bahia (Brasil), onde ocorre em áreas de campo rupestre. Esta nova espécie é proximamente relacionada à M. mucugensis Wurdack, mas pode ser facilmente reconhecida por seu hábito semi-prostado a procumbente, indumento glandular-hirsuto, vináceo, ramos flexuosos, folhas inconspicuamente reticuladas na face abaxial, conectivos muito curtamente prolongados abaixo das tecas, estilete curvo no ápice, n?o ultrapassando o comprimento das anteras, e fruto pêndulo.

     

Carbohydrate and Ethane Release with <Emphasis Type="Italic">Erwinia carotovora</Emphasis> Subspecies <Emphasis Type="Italic">betavasculorum</Emphasis><Emphasis Type="Italic">–</Emphasis>Induced Necrosis

Erwinia carotovora subspecies betavasculorum, also known as E. betavasculorum and Pectobacterium betavasculorum, is a soil bacterium that has the capacity to cause root rot necrosis of sugarbeets. The qualitatively different pathogenicity exhibited by the virulent E. carotovora strain and two avirulent strains, a Citrobacter sp. and an Enterobacter cloacae, was examined using digital analysis of photographic evidence of necrosis as well as for carbohydrate, ethane, and ethylene release compared with uninoculated potato tuber slices. Visual scoring of necrosis was superior to digital analysis of photographs. The release of carbohydrates and ethane from potato tuber slices inoculated with the soft rot necrosis-causing Erwinia was significantly greater than that of potato tuber slices that had not been inoculated or that had been inoculated with the nonpathogenic E. cloacae and Citrobacter sp. strains. Interestingly, ethylene production from potato slices left uninoculated or inoculated with the nonpathogenic Citrobacter strain was 5- to 10-fold higher than with potato slices inoculated with the pathogenic Erwinia strain. These findings suggest that (1) carbohydrate release might be a useful measure of the degree of pathogenesis, or relative virulence; and that (2) bacterial suppression of ethylene formation may be a critical step in root rot disease formation.     

<Emphasis Type="Italic">Luteoamylascus aculeatus</Emphasis> (Pezizomycetes,Pezizaceae): a new genus and species near the <Emphasis Type="Italic">Pachyphlodes</Emphasis>–<Emphasis Type="Italic">Amylascus</Emphasis> lineage

The new taxon Luteoamylascus aculeatus described in this article is proposed to accommodate two collections of a hypogeous ascomycete from central Spain, characterized by a tomentose yellowish peridium, labyrinth-like gleba filled with whitish hyphae, and intensely reacting amyloid asci. ITS, 28S, and RPB2 data suggest that this new taxon is an independent lineage proposed here as the new genus Luteoamylascus. Until now, this lineage was only known from ectomycorrhizal root tips and mitotic spore mats. In phylogenetic analyses, the Luteoamylascus lineage is placed close to the genera Amylascus, Pachyphlodes, and Scabropezia. Morphological data suggest an affinity with Amylascus.     

Gene–environment interactions between <Emphasis Type="Italic">ERCC2</Emphasis>, <Emphasis Type="Italic">ERCC3</Emphasis>, <Emphasis Type="Italic">XRCC1</Emphasis> and cadmium exposure in nasal polyposis disease

Gene–environment interactions have long been known to play an important role in complex disease aetiology, such as nasal polyposis (NP). The present study supports the concept that DNA repair gene polymorphisms play critical roles in modifying individual susceptibility to environmental diseases. In fact, we investigated the role of polymorphisms in DNA repair genes and cadmium as risk factors for Tunisian patients with NP. To the best of our knowledge, this is the first report on the impact of combined effects of cadmium and ERCC3 7122 A>G (rs4150407), ERCC2 Lys751Gln (rs13181) and XRCC1 Arg399Gln (rs25487) genes in the susceptibility to NP disease. Significant associations between the risk of developing NP disease and ERCC2 [odds ratio (OR)?=?2.0, 95 % confidence interval (CI)?=?1.1–3.7, p?=?0.023] and ERCC3 (OR?=?2.2, 95 % CI?=?1.2–4.1, p?=?0.013) genotypes polymorphisms were observed. Blood concentrations of Cd in NP patients (2.2 μg/L) were significantly higher than those of controls (0.5 μg/L). A significant interaction between ERCC3 (7122 A>G) polymorphism and blood-Cd levels (for the median of blood-Cd levels: OR?=?3.8, 95 % CI?=?1.3–10.8, p?=?0.014 and for the 75th percentiles of blood-Cd levels: OR?=?2.7, 95 % CI?=?1.1–7.2, p?=?0.041) was found in association with the risk of NP disease. In addition, when we stratified ERCC2, ERCC3 and XRCC1 polymorphism genotypes by the median and 75th percentiles of blood-Cd levels, we found also significant interactions between ERCC2 (Lys751Gln) and ERCC3 (7122 A>G) genotypes polymorphism and this metal in association with NP disease. However, no interaction was found between XRCC1 (Arg399Gln) polymorphism genotypes and Cd in association with NP disease.     

Isolation and characterization of a <Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N′</Emphasis>-dicyclohexylcarbodiimide-resistant mutant of <Emphasis Type="Italic">Methanothermobacter thermautotrophicus</Emphasis> with alterations to the ATP synthesis machinery

A spontaneous mutant of Methanothermobacter thermautotrophicus resistant toward the ATP-synthase inhibitor N,N′-dicyclohexylcarbodiimide (DCCD) was isolated. DCCD normally inhibits methanogenic electron-transport-driven ATP synthesis, however, the DCCD-resistant strain exhibited methanogenesis in the presence of 300 μmol/L DCCD. Total ATP synthesis was shown to be higher in the mutant strain, both in the presence and absence of DCCD. These results suggested a modification in the ATP-synthesizing system of the mutant strain. Using Blue Native PAGE combined with MALDI TOF/TOF mass spectrometry, increased concentrations of both the A₁ and A_o subcomplexes of the A₁A_o-type synthase were identified in the mutant strain. However, no alterations were found in the structural genes (atp) for the A₁A_o ATP synthase. The results imply that DCCD resistance is a consequence of increased A₁A_o ATP synthase expression, and suggest that genes involved in regulating synthase expression are responsible for DCCD resistance.     

Synthesis of disaccharides using β-glucosidases from <Emphasis Type="Italic">Aspergillus niger</Emphasis>, <Emphasis Type="Italic">A. awamori</Emphasis> and <Emphasis Type="Italic">Prunus dulcis</Emphasis>

Objective

Glucose conversion into disaccharides was performed with β-glucosidases from Prunus dulcis (β-Pd), Aspergillus niger (β-An) and A. awamori (β-Aa), in reactions containing initial glucose of 700 and 900 g l^?1.

Results

The reactions’ time courses were followed regarding glucose and product concentrations. In all cases, there was a predominant formation of gentiobiose over cellobiose and also of oligosaccharides with a higher molecular mass. For reactions containing 700 g glucose l^?1, the final substrate conversions were 33, 38, and 23.5% for β-An, β-Aa, and β-Pd, respectively. The use of β-An yielded 103 g gentiobiose l^?1 (15.5% yield), which is the highest reported for a fungal β-glucosidase. The increase in glucose concentration to 900 g l^?1 resulted in a significant increase in disaccharide synthesis by β-Pd, reaching 128 g gentiobiose l^?1 (15% yield), while for β-An and β-Aa, there was a shift toward the synthesis of higher oligosaccharides.

Conclusion

β-Pd and the fungal β-An and β-Aa β-glucosidases present quite dissimilar kinetics and selective properties regarding the synthesis of disaccharides; while β-Pd showed the highest productivity for gentiobiose synthesis, β-An presented the highest specificity.

     

<Emphasis Type="Italic">halfman</Emphasis>, an<Emphasis Type="Italic"> Arabidopsis</Emphasis> male gametophytic mutant associated with a 150 kb chromosomal deletion adjacent to an introduced<Emphasis Type="Italic"> Ds</Emphasis> transposable element

To identify genes that play an important gametophytic role during pollen development, an Arabidopsis transposon (DsE) mutagenised population was screened for marker segregation ratio distortion. We report the characterisation of a male gametophytic mutant termed halfman (ham) that results in an aborted pollen phenotype in mature anthers. The genetic transmission efficiency of DsE was 6.6% through the male and 98.4% through the female, which suggested that HAM may encode essential male-specific component(s) required for pollen development. Molecular analysis of the insertion site revealed a single copy of the DsE element inserted into the second exon of the RLK5 gene that was adjacent to a large (~150 kb) genomic deletion. The deleted region is predicted to encode 38 genes and to include one or more genes with important function(s) during pollen maturation and seed development.     

In vitro growth response of <Emphasis Type="Italic">Phytophthora cactorum</Emphasis>, <Emphasis Type="Italic">P. nicotianae</Emphasis> and <Emphasis Type="Italic">P.</Emphasis> × <Emphasis Type="Italic">pelgrandis</Emphasis> to antibiotics and fungicides

The reactions of isolates of Phytophthora cactorum, P. nicotianae and P. × pelgrandis to metalaxyl, mancozeb, dimethomorph, streptomycin and chloramphenicol were tested to obtain information about the variability of resistance in these pathogens. Distinct genetic groups showed significant differences in resistance to all tested substances except streptomycin. In response to streptomycin, the growth inhibition rates of distinct groups did not differ significantly. The most remarkable differences were detected in the reactions to chloramphenicol and metalaxyl. Discriminant analysis evaluating the effect of all substances confirmed the differences among the groups, which are in agreement with the differences revealed by earlier DNA analyses.     

Retiolitid graptolites from the collection of Hermann Jaeger II: <Emphasis Type="Italic">Cometograptus</Emphasis>, <Emphasis Type="Italic">Spinograptus</Emphasis> and <Emphasis Type="Italic">Plectograptus</Emphasis>

Graptolites from the Jaeger collection at the Museum für Naturkunde (Berlin, Germany) provide important information on structural details of Silurian (Wenlock–Ludlow) retiolitids as well as for the biostratigraphic and biogeographic distribution of these magnificent graptolites. Species of the genera Cometograptus, Spinograptus and Plectograptus are described from isolated glacial boulder material, collected in northern Germany and from shale specimens found in the Lower Graptolite Shale of Thuringia. The biostratigraphic placement of material derived from glacial erratic boulders, however, is far from being precise. The fauna associated with the neotype of Plectograptus macilentus in the ‘Unterer Graptolithenschiefer’ of Thuringia is discussed and illustrated. Cometograptus alfeisenacki from the Cyrtograptus lundgreni Biozone is recognized as a new species. The genus is discovered for the first time in North German glacial erratic boulders.     

Differential expression of <Emphasis Type="Italic">Gnrh2</Emphasis>, <Emphasis Type="Italic">Gthβ</Emphasis>, and <Emphasis Type="Italic">Gthr</Emphasis> genes in sterile triploids and fertile tetraploids

Gonadotropin-releasing hormone (GnRH), gonadotropin hormone (GTH), and gonadotropin hormone receptor (GTHR) are the pivotal signal molecules of the hypothalamic-pituitary-gonad (HPG) axis, which plays a crucial role in regulating gonadal development in vertebrate. In this study, we comparatively analyze the expression characteristics of Gnrh2, Gthβ, and Gthr in red crucian carp diploids, triploids, and allotetraploids. The expression patterns of these genes are similar in the three fish ploidy types: the Gnrh2 gene is expressed in midbrains, pituitaries, and gonads; the Gthβ gene is expressed in pituitaries; the Gthr gene is mainly expressed in gonads. These results indicate that the three genes participate in the regulation of gonadal development. By real-time polymerase chain reaction and in situ hybridization, we find that, among these three fish ploidy types, the expression level of Gthr in the gonads of triploids is lower than those of diploids and tetraploids; this weakens the combination of GTHR with GTH released from the pituitary and leads to the sterility of triploids, since the gonad cannot produce enough sex steroids. In addition, the low expression of Gthr in triploids may affect the down-regulation of Gthβ, which then affects the down-regulation of Gnrh2; hence, the expression levels of Gnrh2 and Gthβ genes in triploids are the highest after the breeding season. In conclusion, the differential expression of Gnrh2, Gthβ, and Gthr in triploids and tetraploids is related to their sterility and bisexual fertility, respectively.     

<Emphasis Type="Italic">Agrobacterium-</Emphasis>mediated genetic transformation of mint with <Emphasis Type="Italic">E.</Emphasis> <Emphasis Type="Italic">coli</Emphasis> glutathione synthetase gene

Morphologically identical transgenic mint (Mentha arvensis L.) with bacterial glutathione synthetase gene has been developed. Transformed plants were obtained by co-cultivation of leaf disks with Agrobacterium tumefaciens strain LBA 4404 harbouring a binary vector pCAMBIA-CpGS that carried E. coli glutathione synthetase (GS), β-glucuronidase as reporter gene and nptII as selective marker gene for kanamycin resistance. Using a constitutive double CaMV 35S promoter and an rbcS transit peptide, we successfully addressed CpGS to the chloroplasts through pJIT 117 vector. Preculture and the presence of AS in the co-cultivation medium played a significant role in enhancing transformation frequency. The highest transformation frequency was achieved with MS selection medium supplemented with 25% coconut water, 1.12 mg l⁻¹ BAP, 0.2 mg l⁻¹ NAA, 50 mg l⁻¹ kanamycin and 125 mg l⁻¹ cefotaxime. Robust rooting of regenerated shoots was obtained in half-strength liquid MS medium containing 0.2 mg l⁻¹ NAA and 50 mg l⁻¹ kanamycin. The presence and expression of transgenes in transgenics (T₀) was evidenced by GUS histoenzymatic assay, PCR and RT-PCR analysis of nptII and the gene of interest, i.e., GS of putative transgenic leaves. Chromosomal integration of GS gene was confirmed by Southern blot analysis. Transgenic plants were successfully acclimatized in the greenhouse. An overall transformation frequency of 15% was achieved in approximately 3 months of time period. These results are discussed in relation to heavy metal trafficking pathways in higher plants and to the interest of using plastid expression of PCS for biotechnological applications. Akhilesh Kumar and Amrita Chakraborty contributed equally.     

AFLP and SSR polymorphism in a <Emphasis Type="Italic">Coffea</Emphasis> interspecific backcross progeny [(<Emphasis Type="Italic">C. heterocalyx</Emphasis> × <Emphasis Type="Italic">C. canephora</Emphasis>) × <Emphasis Type="Italic">C. canephora</Emphasis>]

An interspecific cross (BC 1) involving a species with one of the largest genomes in the Coffea genus [Coffea heterocalyx (HET), qDNA = 1.74 pg] and a species with a medium-sized genome [Coffea canephora (CAN), qDNA = 1.43 pg] was studied using two types of molecular markers, AFLP and SSR. One hundred and eighty eight AFLP bands and 34 SSR primer pairs were suitable for mapping. The total map length was 1,360 cM with 190 loci distributed in 15 linkage groups. The results were compared to those obtained previously on an interspecific BC 1 progeny involving a species with a medium-sized genome (Coffea liberica var dewevrei, DEW) and a species with one of the smallest genomes (Coffea pseudozanguebariae, PSE). They are discussed relative to three main points: (1) the relevance of the different marker types, (2) the genomic distribution of AFLP and SSR markers, and (3) the relation between AFLP polymorphism and genome size.Communicated by H.F. Linskens     

Synthesis and transformations of a pyrazole containing <Emphasis Type="Italic">α</Emphasis>,<Emphasis Type="Italic">β</Emphasis>-didehydro-<Emphasis Type="Italic">α</Emphasis>-amino acid derivatives

Summary.  2H-Pyran-2-ones 1 were transformed with various hydrazines into (E)- or (Z)-α,β-didehydro-α-amino acid (DDAA) derivatives 4 (and 7) containing a highly substituted pyrazolyl moiety attached at the β-position. With heterocyclic hydrazines, the products 4 were accompanied also by decarboxylated enamines E-6. In order to separate (E/Z)-mixtures of acids, they were transformed to the corresponding methyl esters 9 and 10 by the application of diazomethane. Catalytic hydrogenation under high pressures with Pd/C as a catalyst resulted in the formation of racemic alanine derivatives 11. Received January 29, 2002 Accepted May 27, 2002 Published online December 18, 2002 RID="*" ID="*"  Dedicated with deep respect to Professor Waldemar Adam on the occasion of his 65^th birthday. Acknowledgements We thank the Ministry of Education, Science and Sport of the Republic of Slovenia for the financial support (P0-0503-103). Dr. B. Kralj and Dr. D. Žigon (Center for Mass Spectroscopy, “Jožef Stefan” Institute, Ljubljana, Slovenia) are gratefully acknowledged for the mass measurements. Authors' address: Prof. Marijan Kočevar, Faculty of Chemistry and Chemical Technology, University of Ljubljana, Aškerčeva 5, SI-1000 Ljubljana, Slovenia, E-mail: marijan.kocevar@uni-lj.si     

Characterization of the new β-glucuronidase from <Emphasis Type="Italic">Streptococcus equi</Emphasis> subsp. <Emphasis Type="Italic">zooepidemicus</Emphasis>

Recently, a new gene encoding β-glucuronidase from Streptococcus equi subsp. zooepidemicus (SEZ) was identified and expressed in Escherichia coli. In this paper, the characterization of the enzyme is described. Specific enzyme activity was 120,000 U/mg purified protein at 37°C and pH = 7.0. The temperature and pH value, at which the enzyme has the highest specific activity, were determined and were found to be approximately 52°C and 5.6, respectively. The mutant strain SEZ glcHis was designed for the efficient isolation of β-glucuronidase from S. equi subsp. zooepidemicus. It was observed that the specific activity of β-glucuronidase in the cytoplasmic extract of a mutated strain was about 45% lower than in the cytoplasmic extract of a wild-type strain. The specific activity of purified β-glucuronidase from SEZ glcHis was four times as low as β-glucuronidase purified from E. coli. Comparing the specific activity of purified streptococcal β-glucuronidase from E. coli with E. coli β-glucuronidase (the enzyme with the highest specific activity was supplied by Sigma), the former is 1.8 higher than the latter.     

Peripheral Assessment of the Genes <Emphasis Type="Italic">AQP4</Emphasis>, <Emphasis Type="Italic">PBP</Emphasis> and <Emphasis Type="Italic">TH</Emphasis> in Patients with Parkinson’s Disease

Parkinson’s disease (PD) typically appears in late middle-aged and in elderly persons progressing over a period of several years. The characteristic pathological features of PD patients include defective motor function and cognitive function affecting the quality of life of PD patients. Oxidative stress is considered to a play a central role along with various other factors in the pathogenesis of PD and the incidence and prevalence of the disease is incessantly increasing worldwide. The objective of the current study was to assess mRNA expressional changes of AQP4, TH and PBP in blood samples of control and patients with PD. The study included 30 healthy controls and 90 PD patients subjected to treatment through the entire period of the study. RNA isolation was carried out using blood samples of the subjects recruited in the study and used for RT-PCR analysis of AQP4, TH as well as PBP. The mRNA expressions of AQP4 and TH were found to be reduced whereas that of PBP was found to be elevated when compared with those of healthy control samples. The statistically analysed data were presented which could be helpful for appreciation of PD pathology reflecting in the blood samples of PD population.     

Functional expression of the lipase gene Lip2 of <Emphasis Type="Italic">Pleurotus</Emphasis> <Emphasis Type="Italic">sapidus</Emphasis> in <Emphasis Type="Italic">Escherichia</Emphasis> <Emphasis Type="Italic">coli</Emphasis>

The lipase Lip2 of the edible basidiomycete, Pleurotus sapidus, is an extracellular enzyme capable of hydrolysing xanthophyll esters with high efficiency. The gene encoding Lip2 was expressed in Escherichia coli TOP10 using the gene III signal sequence to accumulate proteins in the periplasmatic space. The heterologous expression under control of the araBAD promoter led to the high level production of recombinant protein, mainly as inclusion bodies, but partially in a soluble and active form. A fusion with a C-terminal His tag was used for purification and immunochemical detection of the target protein. This is the first example of a heterologous expression and periplasmatic accumulation of a catalytically active lipase from a basidiomycete fungus.     

Brood cell size of <Emphasis Type="Italic">Apis</Emphasis> <Emphasis Type="Italic">mellifera</Emphasis> modifies the reproductive behavior of <Emphasis Type="Italic">Varroa</Emphasis> <Emphasis Type="Italic">destructor</Emphasis>

We undertook a field study to determine whether comb cell size affects the reproductive behavior of Varroa destructor under natural conditions. We examined the effect of brood cell width on the reproductive behavior of V. destructor in honey bee colonies, under natural conditions. Drone and worker brood combs were sampled from 11 colonies of Apis mellifera. A Pearson correlation test and a Tukey test were used to determine whether mite reproduction rate varied with brood cell width. Generalized additive model analysis showed that infestation rate increased positively and linearly with the width of worker and drone cells. The reproduction rate for viable mother mites was 0.96 viable female descendants per original invading female. No significant correlation was observed between brood cell width and number of offspring of V. destructor. Infertile mother mites were more frequent in narrower brood cells.     

Synthesis of <Emphasis Type="Italic">N</Emphasis>-<Emphasis Type="Italic">Z</Emphasis>, <Emphasis Type="Italic">N</Emphasis>′-Formyl α-Amino Acid Derived Gem-Diamines

A variety of N-carbobenzoxy, N′-formyl gem-diaminoalkyl derivatives have been obtained through Goldsmith-Wick reaction of Z-α-amino acid/peptide acid derived isocyanates with 96% HCOOH in presence of 4-dimethylaminopyridine (DMAP) as catalyst. The reaction proceeds to completion within 2–4 h and results in good yields of the products isolated as stable solids.     

<Emphasis Type="Italic">Berlinia korupensis</Emphasis> (Leguminosae <Emphasis Type="Italic">–</Emphasis> Caesalpinioideae), a new tree species from Cameroon

Summary  The tree species Berlinia korupensis Mackinder & Burgt is described as new. The species is endemic to the southern part of Korup National Park in Cameroon. Seventeen trees have been found so far, the largest being 42 m high and having a trunk diam. of 88 cm. The new species is assessed as Critically Endangered (CR D) under the criteria of IUCN. Two distribution maps are included; one map indicating the single locality in Cameroon near the Nigerian border where the new species was found and another map of the permanent plot where 14 of the 17 trees were recorded. A line drawing is also included, along with colour photographs of the flowers and the trunk.