Process Biochemistry 26 (1991) 189-190

Patent Survey

This is the second in a regular series of articIes compiled by Marten Terpstra covering a selection of recent patents from Europe, USA and Japan.

A Water Treatment Device

(World patent application 91104229, Biological Control Systems, Australia)

Apparatus for treating water, such as devices for treating water in cooling towers, often suffers from dirt accumulation, microbial activity in return condenser water, the forming of

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scale, and the corrosion of air conditioning plants cooled by condenser water.

Charlick has developed a water treatment device (World patent application 9 l/04229). The invention has a major application in cooling towers (see Fig. 1) for the prevention of Legionnaires’ disease. Ultra-violet light is applied in a novel manner to sterilise the entire cooling tower water volume typically 25 times per hour by treating the entire condenser return pipe (2) water flow. A mechanical cleaning system comprising sweeper arms and supply

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Fig. 1.

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Process Biochemistry (26) (1991)-o 1991 Elsevier Science publishers Ltd, England

pickup pipes (not illustrated) continually cleans the tower basin (4) by agitating the water and lifting and removing settled solids. This is driven by a side- stream water circuit which also includes a filter (8) and a back-flush recovery tank (23), and an electromagnetic or electrochemical water treatment device (10) which controls scale and corrosion without water ‘bleed off’ to waste (29).

Hydrolysis of Hemicellulose by Immobilized Enzymes

(World patent application 91103566, Cultor Ltd, Helsinki, Finland)

A major problem in the hydrolysis of a technical hemicellulose solution by immobilized enzyme is the high salt content of the solution. An ionic material shows a tendency to displace the enzyme from the surface of the carrier so that the column loses rapidly its enzyme activity. Mustranta et al. found a process which is characterized by adjusting the pH of an aqueous solution containing hemicellulose oligosaccharides and optionally ionic components to a value within a weakly acidic range and contacting the solution with a hemicellulolytic enzyme or a mixture of enzymes obtained from the fermentation of a microorganism of the Trichoderma genus, or a fraction thereof, and being immobilized on a regenerable weak cation exchange carrier without the addition of fixing additives, and recovering xylose from the solution.

The microorganism of the Trichoderma genus is Trichoderma longibrachiatum (former name Trichoderma reesei). The weak cation exchange carrier is proposed to be an agglomerated carboxymethyl cellulose strengthened with polystyrene.

A Process for Homogenizing or Separating Liquid Manure

(World patent application 91/03440, Henkel AG, Dusseldorf, FRG)

The problems inherent in the purification of waste water or ground water containing rising amounts of animal manure is well known. Many solutions have been proposed to solve the

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problems at low cost. One of them is claimed by Hirsinger (World patent application 9 l/03440).

The process for homogenizing or separating liquid manure is characterized by the initial stage, in which an aqueous solution of a metal silicate is added to the liquid manure, and a subsequent stage, in which the non-aqueous constituents of the liquid manure are co-precipitated at least partly by precipitating the silicic acids in the mixture. Preferably, sodium and/or potassium silicate solutions are used in amounts of 0.5 to 3 % by weight in relation to the manure.

A Method of Cultivating Cells in Hollow Microspheres

(European patent application 418796, Hoechst AC, Frankfurt am Main, FRG)

A large number of methods are known with which complete cells can be immobilized e.g. Klein and Wagner Appl. Biochem. Bioeng. 4 (1983) 1 l-51. These methods, however, appear to suffer from problems caused by the breakthrough of cells through the walls (gel walls) of the microspheres. Buchholtz et al. have found a method (European patent application 418796) which consists of the cultivation of cells in hollow microspheres, the membranes of which consist of an anionic polysaccharide gel or a polyelectrolyte membrane, characterised by the microspheres being in a solid bed, and by the fact that hybridoma cells are cultivated. The membrane may consist of an alginate gel as well. During the novelty search by the European Patent Office no relevant earlier document was located.

Copies of the references cited can be obtained from the following organizations, or at the Patent Ofices of the respective countries.

European Patent Ofice, Rijswijk, The Netherlands; The Netherlands Patent Ofice, Rijswijk, The Netherlands; The Patent Information Department of TNO, Rijswijk, The Netherlands; The International Patent Research Ofice IPRO, PO Box 16260, 2500 BG, The Hague, The Netherlands ; Univentio. PO Box 16056, The Hague, The Netherlands.