Ulrich Soltmann

• Dr. rer. nat.
• Senior Researcher, Group Leader at GMBU e.V.

Behavioral responses are considered sensitive and effective indicators of organism stress. As the demand for standardized coral toxicity tests grows, innovative tools that allow for automatic and quantitative measurements of these behaviors may complement ecotoxicological studies. The rapid growth of competitive marine algae in aquaculture systems...

In the early stages after larval settlement, coral spat can be rapidly overgrown and outcompeted by algae, reducing overall survival for coral reef replenishment and supply for restoration programs. Here we investigated three antifouling (AF) coatings for their ability to inhibit algal fouling on coral settlement plugs, a commonly-used restoration...

In the early stages after larval settlement, coral spat can be rapidly overgrown and outcompeted by algae, reducing overall survival for coral reef replenishment and supply for restoration programs. Here we investigated three antifouling (AF) coatings for their ability to inhibit algal fouling on coral settlement plugs, a commonly-used restoration...

Ziel des Vorhabens HIGS "Hochintegrierte Ganzzellsensoren für die Umwelt-und Medizintechnik" war die Entwicklung einer neuartigen Generation von Ganzzellsensoren, welche durch die Reaktion lebender Zellen die Bewertung der biologischen Wirkung von biomolekularen oder nichtbiologischen Analyten ermöglichen. Die innovative Lösung soll es weiterhin er...

Thin layers and patterned dot arrays of sodium alginate containing living microalgal cells were deposited onto glass carriers which were subsequently gelled using amino-functionalized silica sol to obtain reinforced alginate hydrogels. The resulting alginate/silica hybrid materials showed improved stability in salt-containing solutions compared to...

The atrazine-degrading bacterial strain Pseudomonas sp. ADP was immobilized by the sol–gel process within thin silica layers coated onto water-retaining carrier materials (expanded clay pellets and scoria). The performance of the obtained biohybrid material has been investigated concerning long-term activity under non-growth conditions. Experiments...

Nanometer sized metal particles are used in many applications as antimicrobial materials. However in public discussion nanoparticular materials are a matter of concern due to potential health risks. Hence there is a certain demand for alternative antimicrobial acting materials. For this, the aim of this work is to realize an antimicrobial active ma...

Immobilization of microorganisms within an inorganic host has become widely used, leading to the design of bioreactors and biofilters for bioremediation systems as well as whole-cell biosensors. The most common used sol-gel matrix for cell encapsulation is based on silica due to its biocompatibility and its mild polymerization conditions. Combinin...

Biofilters with long lifetime and high storage stability are very important for bioremediation processes to ensure the readiness at the occurrence of sudden contaminations. By using the freeze-gelation technique, living cells can be immobilized within a mechanically and chemically stable ceramic-like matrix. Due to a freeze-drying step, the embedde...

Microalgae and ground macroatgae can be fixed on fibers and textiles by use of sol-gel coating agents. By this, the biofunctionality of algae can be fixed on textiles and lead to biofunctionalized textiles. Examples for promising application are given in the fields of bioreactors, water treatment and antimicrobial functional textiles.

Living bacteria (Rhodococcus ruber) and yeast (Saccharomyces cerevisiae) cells can be embedded within magnesium phosphate cement (MPC). The cements are prepared by the admixture of microorganisms to a water-based slurry system of Mg3(PO4)2 powder and ammonium phosphate solution whereas the setting of the slurry occurs within few minutes. To test th...

The development of long-term storable biofilters containing bacteria which are capable to degrade recalcitrant environmental compounds like the fuel oxygenates methyl tert-butyl ether (MTBE) and ethyl tert-butyl ether (ETBE) is of special interest for the treatment of contaminated water. Fuel oxygenates have been proven to be more persistent to bio...

Algae-silica hybrid materials for biosorption purposes were prepared using sol-gel technology. The resulting biological ceramics (biocers) ought to combine the mechanical stability and porosity of the silicate matrix with the algae's capability for the biosorption for heavy metals. The structure, mechanical properties, and sorption capability of su...

A current trend in the field of bio-engineered materials is the use of inorganic oxide nanosols for the immobilization of living Microorganisms by the sol-gel technique. The mechanical, chemical, thermal and photochemical stability of the inorganic host matrix and the great variety of applicative forms (coatings, granules, shaped materials etc.) ar...

Two possible methods are described for using sol–gel technology to immobilize living microorganisms, either embedding the cells within thin silica layers, or using the technique of freeze-gelation to immobilize microorganisms within molded ceramic parts. The preparation and structure of both biocer variants are outlined, and examples are given for...

Biocer coatings consisting of living, cellulose-forming Glucanoacetobacter xylinus bacteria immobilised within a modified silica matrix are able to metabolise glucose to extra-cellular cellulose fibres. The sol-gel technology makes it possible to fix a network of cellulose-forming bacteria and/or cellulose fibres onto various material surfaces, e.g...

New biocer materials consisting of the living microalgae cells Haematococcus pluvialis immobilised within modified sol–gel silica layers can produce the metabolic carotinoid dye astaxanthin after being coated on glass then cultivated. The layer stability and viability of the embedded microalgae depends on the preparation, storage, cultivation, stre...

The germination rate of sol-gel immobilized spores of B. sphaericus JG-A12 in thin silica layers is 5-8-fold enhanced after preincubation with an 1:1 chelate of calcium and dipicolinic acid. This germination potential is conserved during long-time storage of 2.5 years.

Stable shaped ceramic materials with embedded living cells that are applicable as biocatalytic packing material in bioreactors can be prepared by modification of the usual silica sol−gel process. The admixture of commercial alumina fibers (2−3 μm in diameter) shows an excellent reinforcing effect. By a simple casting process and drying in air, bioc...

Biologically modified ceramics (biocers) are understood as a class of nanocomposites which combine biocomponents with ceramic-like matrices. Biocers containing biocomponents can be prepared as a bulk material or as coatings by sol–gel and freeze-cast techniques from inorganic nanosols or by special CVD methods. By avoiding critical preparation cond...

Apart from chemical and physical factors influencing mobility of radionuclides, microbial metabolism also plays a decisive role in enhancing or retarding migration effects. Bacteria are able to reduce or oxidize metals and also to accumulate and bind them. In this work biosorption of U by cells, spores and S-layers of a U mining waste pile isolate...

Freeze gelation was used for immobilization and conservation of living microorganisms in inorganic solids. The irreversible sol–gel transition of a mixture of colloidal silica, ceramic powder and biocomponent by freezing (freeze gelation or freeze casting) enables the production of low-cost, porous, crack-free green bodies with nearly zero shrinkag...

Biological ceramic composites (biocers) made according to aqueous sol-gel protocol were used as selective metal binding filters. The biological component of the biocers Bacillus sphaericus JG-A12 was isolated from a uranium mining waste pile. Vegetative cells and spores of this strain are known to bind selectively U, Cu, Al, Cd, and Pb in large amo...

Different types of biocers were prepared by dispersing vegetative cells, spores and surface layer proteins (S-layers) of Bacillus sphaericus JG-A12 in aqueous silica nanosols, gelling or coating on glass, and drying. The enzymatic activity of embedded B. sphaericus cells depends noticeably on the water content of the biocer. The cells are destroyed...

Upon exposure to the aromatic xenobiotics 2,6-dimethylphenol and 4-nitrophenol, distinct changes occurred in the microbial structure of the rhizosphere of the helophytes Carex graclis, Phalaris arundinacea and Juncus effusus (total number, diversity, abundance). Generally speaking, exposure to xenobiotics resulted in an increase in the total number...

The aromatic xenobiotics 2,6-dimethylphenol, 4-chlorophenol and naphthalene were removed using hydroponic cultures of Carex gracilis and Juncus effusus and using sand-bed reactors planted with Carex gracilis and Juncus effusus, respectively, under batch and flow-through conditions. Concentrations of 20 mg/l organic pollutant in the case of 4-chloro...

Cells, spores and the surface layer protein (S-layer) of the Bacillus sphaericus strain JG-A12, recovered from a uranium mining waste pile, were embedded in SiO2 matrices by using sol-gel techniques. Sorption and desorption of uranium and copper by the free biocomponents and the obtained biological ceramics (biocers) were investigated. The biocer w...

Degradation of 2,6-dimethylphenol, 4-nitrophenol and naphthalene, which are potential aromatic contaminants of the environment was investigated in the root sphere of helophytes applying both batch- and continuous culture conditions. The degradation processes were performed with hydroponic or sand-bed cultures. The influence of these xenobiotics wer...