Provided are a potentiometric biosensor (100) and a method for detecting urea concentration in a sample. The potentiometric biosensor (100) comprises an indication electrode (23) and a reference electrode (24). A second reaction reagent on the indication electrode (23) comprises a urease but does not comprise an electron transporter. A first reaction reagent on the reference electrode (24) comprises an electron transporter but does not comprise a urease. In the case where no external voltage is applied, after a blood sample has been added, the urease catalyzes the reaction of urea in the sample, thereby causing a potential difference between the indication electrode (23) and the reference electrode (24). Furthermore, the potential difference between the indication electrode (23) and the reference electrode (24) is in a linear relationship with the urea concentration in the sample, and the urea concentration in the sample can be calculated according to such linear relationship.

Disclosed herein is a process of forming an inorganic water barrier layer on top of a porous substrate by means of microbially induced calcium carbonate or calcite precipitation (MICP), the process comprising the steps of: providing a porous substrate having a surface; depositing a urease-active slurry onto the surface of the porous substrate to form a bioslurry layer; and subjecting the bioslurry layer to one or more treatments with an aqueous solution comprising urea and a water barrier source material to convert the bioslurry layer into an inorganic water barrier layer. The process further comprises a step of covering the bioslurry layer with a layer of a porous material that has a surface, where the one or more treatments with an aqueous solution comprising urea and a water barrier source material are initially applied to the surface of the porous material. The porous material acts as a reservoir for the aqueous solution to sustain the biocementation of bioslurry into the desired inorganic water barrier layer.

Compositions of peritoneal dialysis solutions and metabolizing enzymes, and their uses to treat disorders associated with elevated levels of metabolites are disclosed. Animal models of hyperoxalemia are also disclosed.

The present disclosure provides a method of biocementation comprising contacting a granular, cohesionless soil with a solution, wherein the solution comprises urea, urease, a source of calcium ions, and a source of non-urease proteins, wherein the urea, urease, source of calcium ions, and source of non-urease proteins are provided in effective amounts suitable to cause crystallization of calcium carbonate.

The invention relates to a device and method for detecting a specific analyte in a liquid sample. The device that can be used in the method contains at least one fluid line, at least one receiving region for receiving a liquid sample, at least one enzymes region containing at least one determined enzyme and/or at least one acidification region containing at least one acid. The device also contains at least one reaction region used to form gas bubbles. The fluid line transports the liquid sample from the receiving region via the enzyme region and/or the acidification region to the reaction region by means of capillary forces and/or at least one micropump allowing fast, simple and cost-effective detection of a specific analyte in a liquid sample, the detection being carried out with a high level of sensitivity, specificity and precision. The invention further relates to uses of the device.

The invention is directed to kits, compositions, tools and methods comprising a cyclic industrial process to form biocement. In particular, the invention is directed to materials and methods for decomposing calcium carbonate into calcium oxide and carbon dioxide at an elevated temperature, reacting calcium oxide with ammonium chloride to form calcium chloride, water, and ammonia gas; and reacting ammonia gas and carbon dioxide at high pressure to form urea and water, which are then utilized to form biocement. This cyclic process can be achieved by combining industrial processes with the resulting product as biocement. The process may involve retention of calcium carbonate currently utilized in the manufacture of Portland Cement.

The invention is directed to compositions and methods for the manufacture of pigmented solids structures for which can be used for construction and/or decoration. Manufacturing comprises fixing one or more pigments to an aggregate material such as crushed rock, stone or sand. The pigmented aggregate is incubated with urease or urease producing microorganisms, an amount of a nitrogen source such as urea, and an amount of calcium source such as calcium chloride forming calcite bridges between particles of aggregate. The resulting solid has a hardness and colorfastness for most any construction material. Using selected aggregate and pigment, the process also provides for the manufacture of simulated-stone materials such as clay or granite bricks or blocks, marble counter-tops, and more. The invention is also directed to composition containing microorganisms and pigment as kits that can be added to most any aggregate materials.

The present invention provides methods for mineral precipitation and/or cementation of permeable or fractured non-porous materials using isolated urease.

The invention is directed to compositions and methods for the manufacture of pigmented solids structures for which can be used for construction and/or decoration. Manufacturing comprises fixing one or more pigments to an aggregate material such as crushed rock, stone or sand. The pigmented aggregate is incubated with urease or urease producing microorganisms, an amount of a nitrogen source such as urea, and an amount of calcium source such as calcium chloride forming calcite bridges between particles of aggregate. The resulting solid has a hardness and colorfastness for most any construction material. Using selected aggregate and pigment, the process also provides for the manufacture of simulated-stone materials such as clay or granite bricks or blocks, marble counter-tops, and more. The invention is also directed to composition containing microorganisms and pigment as kits that can be added to most any aggregate materials.

Disclosed herein is a process of forming an inorganic water barrier layer on top of a porous substrate by means of microbially induced calcium carbonate or calcite precipitation (MICP), the process comprising the steps of: providing a porous substrate having a surface; depositing a urease-active slurry onto the surface of the porous substrate to form a bioslurry layer; and subjecting the bioslurry layer to one or more treatments with an aqueous solution comprising urea and a water barrier source material to convert the bioslurry layer into an inorganic water barrier layer. The process further comprises a step of covering the bioslurry layer with a layer of a porous material that has a surface, where the one or more treatments with an aqueous solution comprising urea and a water barrier source material are initially applied to the surface of the porous material. The porous material acts as a reservoir for the aqueous solution to sustain the biocementation of bioslurry into the desired inorganic water barrier layer.