Microbial community and extracellular polymeric substances analysis of anaerobic granular sludge exposed to selenate,cadmium and zinc

The microbial community and extracellular polymeric substances composition of anaerobic granular sludge exposed to selenate (~10 mg/L), cadmium (Cd) and zinc (Zn) (~2 and 5 mg/L) were investigated by high-throughput sequencing and fluorescence excitation emission matrix (FEEM) spectra, respectively. As a response to selenate, Cd and/or Zn exposure, significant fluorescence quenching of fulvic-like acids and humic-like substances was observed. With selenate, Cd and/or Zn in the influent with respective concentrations of 10, 5 and 5 mg/L, the abundance of the phyla Proteobacteria, Firmicutes, Spirochaetae, Cloacimonetes and Synergistetes increased significantly, and the dominant taxa in the anaerobic granular sludge exposed to Se, Cd and/or Zn were Halothiobacillaceae (10.2%), Pseudomonas (8.8%), Synergistaceae (7.7%), Spirochaetaceae (7.2%), Blvii28 wastewater sludge group (6.7%), Telmatospirillum (4.6%), Veillonellaceae (4.3%), Geobacter (4.0%) and Enterobacteriaceae (3.0%). Compared with the inoculum, the abundance of the archaea Methanobacterium and Methanosaeta decreased to below detection limit in the UASB reactor after 116 days exposure to Se, Cd and Zn.     

Synthesis of a 2,4,6-trisubstituted 5-cyano-pyrimidine library and evaluation of its immunosuppressive activity in a Mixed Lymphocyte Reaction assay

A series of novel pyrimidine analogues were synthesized and evaluated for immunosuppressive activity in the Mixed Lymphocyte Reaction assay, which is well-known as the in vitro model for in vivo rejection after organ transplantation. Systematic variation of the substituents at positions 2, 4 and 6 of the pyrimidine scaffold led to the discovery of 2-benzylthio-5-cyano-6-(4-methoxyphenyl)-4-morpholinopyrimidine with an IC₅₀ value of 1.6 μM in the MLR assay.     

Biotechnological aspects of sulfate reduction with methane as electron donor

Biological sulfate reduction can be used for the removal and recovery of oxidized sulfur compounds and metals from waste streams. However, the costs of conventional electron donors, like hydrogen and ethanol, limit the application possibilities. Methane from natural gas or biogas would be a more attractive electron donor. Sulfate reduction with methane as electron donor prevails in marine sediments. Recently, several authors succeeded in cultivating the responsible microorganisms in vitro. In addition, the process has been studied in bioreactors. These studies have opened up the possibility to use methane as electron donor for sulfate reduction in wastewater and gas treatment. However, the obtained growth rates of the responsible microorganisms are extremely low, which would be a major limitation for applications. Therefore, further research should focus on novel cultivation techniques.     

Context dependence of personalities: risk-taking behavior in a social and a nonsocial situation

Individuals of many species differ consistently in their behavioralreaction to mild novel challenges. Suites of these behaviorsare referred to as behavioral syndromes or personalities. Personalitytraits are often phenotypically and genetically correlated.Therefore, animal personalities are generally considered asbroad characteristics, with one underlying genetical and physiologicalmechanism that is expressed across situations and contexts.Because there are carryover effects between situations, animalsare not entirely flexible in their behavior in each situation.This may cause behaviors to seem nonadaptive in isolated situations.To test whether individuals with different personalities couldreact differently to changes in their environment, we studiedcontext dependence of personalities in the great tit (Parusmajor). We tested birds categorized as either fast or slow explorersfor their latency to come back to a feeding table after a mildstartle (risk-taking behavior) in a nonsocial followed by asocial context. We found that the relation between exploratorybehavior and risk-taking behavior depended on the social context.Females in general returned later in the social test, whilemale reaction to the presence of a conspecific was dependenton their behavioral type. Slow males thereby reacted to thebehavior of the companion and fast males did not. These resultsshow that although personalities have a rigid structure therelation between personality traits is context dependent. Theseresults are discussed in the perspective of the adaptive significanceand maintenance of personalities.     

Construction of integrated genetic linkage maps by means of a new computer package: Join Map

A computerized procedure to contruct integrate genetic maps is presented. The computer program (J oin M ap ) can handle raw data from F₂s, backcrosses and recombinant inbred lines, as well as listed pair-wise recombination frequencies. The procedure is useful for combining linkage data that have been collected in different experiments; the result is a mathematical alignment of the distinct genetic maps. Data from single experiments can be dealt with as well. In view of the fast growing amount of linkage information for molecular markers, which is often being generated by different research groups, integrated maps provide useful information on the map position of genes and DNA markers.
The procedure performs a sequential build-up of the map and, at each step, a numerical search for the best fitting order of markers. Weighted least squares is used for the estimation of map distances.     

A cobblestone cell isolated from the human omentum: the mesothelial cell; isolation,identification, and growth characteristics

Summary Normal human mesothelial cells (NHMC) were isolated from pieces of human omentum. The cell yield was approximately one million cells per square centimeter omentum. The mesothelial cells were identified by their positive staining with monoclonal antibodies against cytokeratins 6 and 18. Transmission electronmicroscopy of cultured NHMC revealed many microvilli on the apical surface and many mitochondria and pinocytotic vesicles in the cytoplasm, indicating active transmembrane transport. Growth of NHMC was directly related to the concentration of human serum or of fetal bovine serum in the growth medium. Addition of epidermal growth factor with or without hydrocortisone resulted in a significant increase of NHMC growth; when endothelial cell growth factor, insulin, or hydrocortisone were added no such increase was observed. Seeding NHMC at densities less than 3000/cm² did not result in monolayer formation. The mesothelial cells were serially passed in growth medium M199 with added 10% fetal bovine serum up to 7 passages. However, after Passage 4 the cells changed into giant cells with an irregular pattern, and a lack of intracellular cytokeratin expression was observed for most of the cells.     

Isomerization of butyrate to isobutyrate by Desulforhabdus amnigenus

Abstract The isomerization of butyrate and isobutyrate was investigated for the sulfate reducer Desulforhabdus amnigenus . Nuclear magnetic resonance (NMR) studies with ¹³C-labelled butyrate showed that isobutyrate was formed by migration of the carboxyl group, in conformity with the butyrate isomerization reaction reported for methanogenic consortia. In addition to D. amnigenus , several other butyrate-degrading sulfate reducers ( Desulfobacterium vacuolatum, Desulfoarculus baarsii and Desulfotomaculum sp.) were capable of butyrate isomerization.     

Tail spine length in the Daphnia galeata complex: costs and benefits of induction by fish

We studied the combined effect of fish kairomones and food conditions on the relative tail spine length (RTL) of five Daphnia taxa, and the interaction of these factors with the vertical distribution of the daphnids. The experiment was done in two large-scale indoor containers, the so-called plankton towers in Plön, Germany. We conducted a competition experiment in which food level and the presence of fish chemicals and later fish were varied. A strong response of RTL to fish kairomones (e.g., longer tail spines), significant differences in RTL between species, but no differences in RTL with water depth were found. Further, we observed that these Daphnia taxa produced a higher RTL only under high food conditions. This suggests that there is a cost related to the production of longer tail spines.In a preliminary study in lake Plußsee, we found that Daphnia had longer average RTL than in the towers. Further, we noted significant differences in RTL between the two sampling dates, which may be related to a lower food level. We also detected a strong inverse correlation between RTL and depth. We discuss the implications of these findings for the co-existence of co-occurring Daphnia species and their hybrids.