Addiciones y correcciones al conocimiento de la liquenoflora foliícola de Costa Rica. La familia Asterothyriaceae y el género Chroodiscus (Thelotremataceae), con un análisis filogenético

The taxonomy of foliicolous representatives of the lichen families Asterothyriaceae (Asterothyrium, Gyalidea, Psorotheciopsis) and Thelotremataceae (Chroodiscus) in Costa Rica is revised. Seven new species and one new variety are described: Asterothyrium anomalum var. pallidum Henssen & Lücking var.n., A. aulaxinoides Lücking sp.n., A. chroodisciforme Lücking sp.n., A. rondoniense Bat. & H. Maia ex Henssen & Lücking sp.n., A. septemseptatum Lücking sp.n., A. tetrasporum Lücking sp.n., A. uniseptatum Lücking sp.n., and Chroodiscus submuralis Lücking sp.n. Asterothyrium gigantosporum Lücking and A. hedbergii Kalb & Vězda are reported from Costa Rica for the first time. On account of morphological and anatomical features, an attempt is made to trace intrageneric relationships in the genus Asterothyrium, and the ascospore type is demonstrated not to correlate well with supposedly natural groups. Furthermore, the systematics of the Asterothyriaceae is briefly discussed. The result of a phylogenetic analysis based on phenotypic characters is not in contradiction with the hypothesis that the genera Gyalidea, Solorinella, Linhartia, Psorotheciopsis, and Asterothyrium, currently placed in three different families, are easily accomodated within a single family Asterothyriaceae. Consequently, Solorinellaceae is placed into synonymy with Asterothyriaceae. In addition, Linhartia is reunited with Psorotheciopsis, since the different ascospore sizes are considered insufficient for generic separation, and the following new combinations are proposed: Psorotheciopsis gyalideoides (Vězda) Henssen & Lücking comb.n. [Bas.: Linhartia gyalideoides Vězda], Psorotheciopsis philippinensis (Rehm) Lücking comb.n. [Bas.: Linhartia philippinensis Rehm. Syn.: L. vezdana Lücking], and Psorotheciopsis varieseptata (Vězda) Henssen & Lücking comb.n. [Bas.: Linhartia varieseptata Vězda].     

中国的几个叶柄生盘菌

本文报道了4个叶柄上生的核盘科分类单元,其中黄山兰斯盘菌为新种,赛氏蜡盘菌为我国新记录。     

A preliminary study on the culture ofDiscomycetes,especially the perfect stage

Summary The author made a study of the culture ofDiscomycetes. About fourty species were studied in vitro. An ascertaining of the conditions inducing the perfect stage was aimed at and as far as these fructifications developed they were studied. From six of these fungiviz., Cenangium ferruginosum Fr.,Encoelia fascicularis (Fr.) Karst.,Mollisia spec.,Pezicula cinnamomea (Fr.) Sacc.,Phialea acuum (Alb. en Schw. ex Fr.) Rehm andSclerotinia sclerotiorum (Lib.) de Bary, apothecia were obtained in culture, the others failed to do so.     

Leaf area expansion and net photosynthetic rate of three bromegrass (Bromus) species

This study measured individual leaf area expansion rate and leaf net photosynthetic rate (P _N) of meadow bromegrass (Bromus riparius Rehm.), smooth bromegrass (Bromus inermis Leyss.) and hybrid bromegrass (B. riparius × B. inermis). Smooth bromegrass expanded individual leaf area 1.5 times faster than meadow bromegrass and hybrid bromegrass. P _N was highest in smooth bromegrass, intermediate in hybrid bromegrass, and lowest in meadow bromegrass. Rapid growth of meadow bromegrass following defoliation compared to smooth bromegrass and hybrid bromegrass could not be explained by higher rates of these measured characteristics.     

ErratumTo: Effect of the osmotic conditions during sporulation on the subsequent resistance of bacterial spores

A set of mutants was generated by targeted deletion of the hsdR loci of two type I restriction modification systems (RMS) identified in Bacillus licheniformis DSM13. Single as well as double knock-outs resulted in strains being readily transformable with plasmids isolated from Bacilli. Introduction of shuttle plasmids isolated from Escherichia coli was routinely possible when the double mutant B. licheniformis MW3 (ΔhsdR1, ΔhsdR2) was used in transformation experiments. Growth and secretion of extracellular enzymes were not affected in any of the mutants. Thus, along with an optimized transformation protocol, this study makes available an urgently needed transformation system for this industrially exploited species. This work is dedicated to Prof. Dr. Hans Jürgen Rehm on the occasion of his 80th birthday.     

A comparative study on the formation of citric acid and polyols and on morphological changes of three strains of free and immobilized Aspergillus niger

Summary The formation of citric acid, oxalic acid, erythritol and glycerol by three strains of Aspergillus niger immobilized in calcium alginate was investigated and compared with that of free cells when cultivated in shake flasks under phosphate limitation. Morphological changes were followed using an electron microscope. The production of acids and polyols, the consumption of glucose and fructose, and also the morphological changes were strain-dependent. The results also reflected the influence of long storage of a strain on productivity, morphological behaviour and phosphate consumption. Offprint requests to: H.-J. Rehm     

Comparison of fermentation properties and specific enzyme activities of free and calcium-alginate-entrapped Saccharomyces cerevisiae

Summary Physiological properties have been determined for calcium-alginate-entrapped Saccharomyces cerevisiae in comparison to cells in suspension under identical culture conditions. Cells grown in the form of microcolonies in the alginate beads showed faster glucose uptake and ethanol productivity with simultaneously decreased product and cell yields. Increased specific hexokinase and phosphofructokinase activities could be determined in these cells. Immobilized single cells showed only slightly enhanced glucose turnover and no higher specific hexokinase activity. The significant alterations in physiology are apparently connected with growth of the cells in aggregates. Offprint requests to: H.-J. Rehm     

Influence of inorganic phosphate and immobilization on Claviceps purpurea

Summary The influence of inorganic phosphate and immobilization on cells of Claviceps purpurea strain 1029/N5 producing ergot peptides in shake culture was examined. Immobilization in Ca-alginate beads resulted in a marked reduction of some metabolic activities, i.e. the periods of alkaloid formation and cell growth were prolonged. High concentrations of inorganic phosphate (1 g/l KH₂PO₄) could reduce or stop alkaloid formation both by free and immobilized cells at any time during fermentation. The optimum phosphate concentration for alkaloid production by immobilized cells (about 0.5 mM) was a quarter of that required by free cells. This optimum shift was attributed to (i) the diminished phosphate demand of immobilized cells, due to their reduced metabolic activities, and (ii) the phosphate-dependent morphological behaviour of the biocatalyst. The observed decrease in alkaloid concentrations during later periods of the fermentation supported the idea of alkaloid-degradative enzymes, activated by high phosphate concentrations. Immobilization showed an advantageous influence on this undesirable effect. Offprint requests to: H.J. Rehm     

In vivo conversion of penicillin N into a cephalosporin type antibiotic by a non-producing mutant of Streptomyces clavuligerus

Summary Intact mycelia of beta-lactam antibiotic producing microorganisms are generally considered to be impermeable to externally fed penicillin. Using growing cells of the non-producing mutant. Streptomyces clavuligerus NP1, it was surprisingly possible to convert externally fed penicillin N into a cephalosporin type of antibiotic.Dedicated to Professor Dr. H. J. Rehm on the occasion of his 60th birthday.     

CENTRUM DEVELOPMENT IN DIDYMELLA BRYONIAE

Early stages of pseudothecium development consist of small pseudoparenchymatous stromata in which ascogonia differentiate. Deeply staining cells in the apical region of the young pseudothecium elongate to form pseudoparaphyses, which grow down to fill the centrum. Ascogenous hyphae grow out from ascogenous cells, located in the basal plectenchyma, and croziers arise and proliferate from the ascogenous hyphae. Bitunicate asci grow up among the pseudoparaphyses and forcibly discharge two-celled hyaline ascospores at maturity. Because centrum development in Didymella bryoniae (Auersw.) Rehm is pseudoparaphysate, the causal agent of gummy stem blight in watermelon is properly placed in the order Pleosporales. The placement of this species in Didymella on the basis of the Ascochyta cucumis Fautr. et Roum. anamorph is supported by centrum structure.     

Coupled reductive and oxidative degradation of 4-chloro-2-nitrophenol by a co-immobilized mixed culture system

Summary The restriction of oxygen transfer in Ca-alginate beads used for the immobilization of microbial cells was applied to a coupled reductive and oxidative microbial degradation of the xenobiotic 4-chloro-2-nitrophenol (CNP). The conversion of CNP by Enterobacter cloacae under anaerobic conditions led to the formation of 4-chloro-2-aminophenol (CAP, 81%) and 4-chloro-2-acetaminophenol (CAAP, 16%) after 50 h incubation. CAP, the main reduction product, was further degraded under aerobic conditions by Alcaligenes sp. TK-2, a hybrid strain isolated by conjugative in-vivo gene transfer. Whereas both degradation steps excluded one another in homogeneous systems with free cells, a coupled reductive and oxidative degradation of CNP was observed in one aerated reactor system after co-immobilization of both strains in Ca alginate. The diameter of the alginate beads used for immobilization was recognized as one main factor determining the properties of this mixed culture system. Offprint requests to: H.-J. Rehm     

A phytosociological study of the macrophytic vegetation of running waters in western lower saxony (Federal Republic of Germany)

A survey was carried out of the macrophytic vegetation in running waters of Western Lower Saxony. Three hundred and eighty-two phytosociological relevées were classified by common table work to 30 vegetation types of different phytosociological validity. The vegetation types are described and floristically characterized. Most of them belong to the complex Sparganium emersum community, which is characterized by the dominant occurrence of the nymphaeid species Sparganium emersum Rehm., Nuphar lutea (L.) Sm., Sagittaria sagittifolia L. and Potamogeton natans L., but magnopotamid-, parvopotamid-, batrachiid- and pleustophyte-dominated communities also occur. Similarity between the different vegetation types was checked by multivariate techniques, one classification technique (minimum variance clustering) and one ordination technique (principal components analysis). Additionally, syndynamical relations between the types were studied by observing the vegetation changes of 46 sample points within 2 years. The relations between different vegetation types are shown by combination of the different approaches. Finally, some more general statements are made regarding the handling of such data sets, as well as the consequences of the results for the classification of macrophytic vegetation in Central European rivers.     

Cellobiose-quinone oxidoreductase —application in monitoring cellobiohydrolase purification

Summary The enzymatic saccharification of cellulose has traditionally been monitored via total reducing sugar analyses. Yet with cellobiohydrolase being a major component of fungal and actinomycete cellulases, there is a need for a more specific measurement of cellobiose besides other soluble cellulodextrin products without interference from glucose, the major product of cellulose saccharification. One approach is to utilize cellobiose: quinone oxidoreductase (CBOase) from the fungus Phanerochaete chrysosporium to monitor saccharification. We describe here methods for the production of CBQase and a specialized application to monitor the chromatographic separation of cellobiohydrolase.Dedicated to Professor Dr. H. J. Rehm on the occasion of his 60th birthday     

Life cycle,meiotic recombination and unilateral gene transfer in methanolotrophic yeasts of the genus Pichia

Summary In order to perform strain improvement of the methanol utilising yeasts Pichia pinus and Pichia lindneri their life cycles were elucidated. Both yeasts are monoecious and self-fertile. Karyogamy by autodiploidization is followed by meiosis leading to Mendelian segregation within the offspring. In Pichia pinus crosses via cell or protoplast fusion is feasible as proven by tetrad analysis. This is not the case in Pichia lindneri. The only possiblity to obtain recombinants in this yeast is brought about by a yet unknown mechanism, leading to a unilateral transfer of genetic material, found after cocultivation of mutants. This is revealed by the evaluation of F1 offspring from meiotic divisions after autodiploidisation. Although analysis of nuclear and mitochondrial DNA revealed rather gross differences not only between the species but also within different strains of Pichia pinus, only a limited exchange of genetic material is possible in interstrain crosses.Dedicated to Professor Dr. H. J. Rehm (Münster) on the occasion of his 60th birthday     

Biodegradation of dichloroacetic acid by freely suspended and adsorptive immobilized Xanthobacter autotrophicus GJ10 in soil

Xanthobacter autotrophicus GJ10 was applied in a packed-bed fermentor to degrade dichloroacetic acid (DCA) in batch-, semicontinuous and continuous culture. Degradation has been studied with freely suspended and adsorptive immobilized cells. To imitate natural soil systems, the fermentor was filled with sand. Concentrations of up to 20 mm DCA were degraded completely. If higher initial concentrations were used, the decrease in pH value inhibited further growth and degradation. In continuous culture the fermentor was inoculated additionally with activated sludge. Over a period of 2 weeks the specialized strain could be retained and no decrease in metabolic activity was observed. A decrease in degradation of DCA was observed when succinate was added as a second substrate. The haloacid dehalogenase was found to be induced by DCA. Non-induced cells showed typical repression of catabolites and diauxic growth with succinate as co-substrate. The results demonstrate that X. autotrophicus GJ10 might be suitable for applications in biological waste treatment systems. Correspondence to: H.-J. Rehm     

Biodegradation of phenanthrene by Arthrobacter polychromogenes isolated from a contaminated soil

Summary Degradation of phenanthrene by Arthrobacter polychromogenes isolated from a contaminated soil was investigated. In experiments in which [9-¹⁴C]-phenanthrene was incubated with cultures of A. polychromogenes containing 150 mg phenanthrene/l it was shown that after 26 h of incubation 47.7% of the recovered radiolabelled carbon originally present was metabolized to ¹⁴CO₂, 47.8% was recovered from the aqueous fraction, and 4.5% remained in the dichloromethane fraction. Increasing phenanthrene concentration in the culture medium resulted in improved growth and degradation rates, probably due to the higher amount of phenanthrene crystals in the medium. Shifting the temperature from 30°C to 35°C did not influence phenanthrene degradation significantly but inhibited cell division of A. polychromogenes. Medium supplementation with glucose led to stimulation of phenanthrene degradation at low amounts of glucose (0.45 g/l) whereas at higher concentrations (3 g/l) phenanthrene mineralization decreased.Professor Dr. D. Behrens dedicated to his 65th birthdayOffprint requests to: H.-J. Rehm     

Distribution of Trichaleurina javanica (Rehm) M. Carbone,Agnello & P. Alvarado (Chorioactidaceae) in India

During the recent field visits to Saurashtra regions of Western India, one of the interesting fungi i.e. Trichaleurina javanica (Rehm) M. Carbone, Agnello & P. Alvarado (Chorioactidaceae, order Pezizales) was collected from Sarkhadiya Hanuman and Sasan (Gir Forest, India). Further confirmation of the identity was carried out by using molecular methods with its DNA barcoding. Review of literature showed that this species was previously reported from India under a different name; the collection here studied is the first one molecularly confirmed. Nucleotide sequence obtained during molecular analysis is submitted into NCBI and is the first record at BOLD data system for its DNA barcode (BOLD ID KSRF-0019).     

Constant dissolved oxygen concentrations in cephalosporin C fermentation: Applicability of different controllers and effect on fermentation parameters

Summary The behaviour and applicability of several controllers for maintaining a constant dissolved oxygen concentration (DO) during the cephalosporin C production with Cephalosporium acremonium in a laboratory fermentor is described. The process controllers were realized on a MC 68000 based process computer using the real-time language PEARL. The discrete signum integral controller showed the best control action. In addition some derived fermentation data were calculated on-line by the process computer.The results obtained by comparison of fermentations carried out at DO between 10% and 40% saturation during ideophase indicate that high DO leads to a high specific production rate for cephalosporin C and a low specific production rate for penicillin N and vice versa. In the range of DO investigated the production of deacetyl and deacetoxy cephalosporin C is not affected by DO. A direct correlation between DO and the yield coefficients Y _P/S and Y _P/X could be established. The yield coefficient Y _P/O for cephalosporin C is constant in the DO range from 10%–40%.Dedicated to Prof. Dr. H. J. Rehm on the occasion of his 60th birthday     

Comparison of ligninolytic activities of selected white-rot fungi

Summary Six fast growing ligninolytic white-rot fungi were compared with Phanerochaete chrysosporium. The results showed that the fungi have similar ligninolytic systems, although minor differences exist. Like in P. chrysosporium the ligninolytic system could be induced by veratryl alcohol in Coriolus versicolor and Chrysosporium pruinosum. These three lignin peroxidase producing fungi were the fastest lignin degraders in stationary cultures, whereas in agitated cultures Bjerkandera adusta showed highest lignin degradation rates. Metabolites accumulating during the degradation of veratryl alcohol were analyzed and compared. Peroxidase production seems to be a common feature of all the tested fungi. Polyclonal antibodies against the lignin peroxidase with pl of 4.65 from P. chrysosporium reacted with the extracellular peroxidases of C. pruinosum, C. versicolor and B. adusta, but not with those of Pleurotus ostreatus.Dedicated to Professor Dr. Hans-Jürgen Rehm on the occasion of his 60th birthday     

Degradation of mixtures of monochlorophenols and phenol as substrates for free and immobilized cells of Alcaligenes sp. A7-2

Summary The biodegradation of the three isomeric monochlorophenols 2-(2CP), 3- (3CP) and 4-chlorophenol (4CP) and phenol by the constructed strain Alcaligenes sp. A7-2 was investigated. Mineralization took place in the order: phenol >4CP >2CP >3CP, whereas 3CP was mineralized only co-metabolically. In substrate mixtures with phenol, degradation of 4CP was decelerated but degradation of 2CP was accelerated. Free cells in batch culture showed biphasic growth with an equimolar mixture of 2CP and 4CP as substrates, perhaps due to diauxie. Degradation patterns obtained with free cells in batch culture were confirmed with immobilized cells in continuous culture. Immobilized cells of Alcaligenes sp. A7-2 built up a biofilm on the lava that was used as filling material in the packed-bed reactors. The continuous cultures remained stable despite increasing input rates of chlorophenol and phenol mixtures up to 1.16 mMo1.1^–1.h^–1 for several weeks. Correspondence to: H.-J. Rehm