GB967234A - Apparatus and method for culturing microorganisms - Google Patents

Abstract

<PICT:0967234/C6-C7/1> <PICT:0967234/C6-C7/2> <PICT:0967234/C6-C7/3> Culturing apparatus for micro-organisms comprises a casing impermeable to culture medium and to the micro-organisms to be cultured, which casing is divided by internal partitions into separate culturing compartments and each partition has interstices or pores through it of a size to permit the micro-organisms being cultured to grow and diffuse from one compartment to the next in succession. The casing 10 and compartments 22 may be formed by folding over a flexible sheet of thermoplastic material and heat sealing together the sides 14 and top 16 of the sheet, and making compartment-forming partitions 20. For the cultivation of gas-forming bacteria, yeast or moulds, the compartments may intercommunicate at their upper ends above the culture medium, Fig. 4 (not shown), the gas produced being vented through a valve. The interstices or pores are formed by a wick 24 extending through each compartment 22; the wick pore size should not be so great as to permit the free flow of culture medium or of the metabolic products. The speed of transfer of the micro-organism culture from compartment to compartment may be decreased by using a wick of smaller pores or of smaller cross-sectional area, or by adding agar or gelatin to the culture medium. The casings may be suspended from their grommets 18. An elongated casing containing, for example, 365 compartments of equal volume may be wound into a roll and packed in a casette during storage, transport and use, Figs. 5 and 6 (not shown). Thermoplastic materials mentioned: polyethylene, polyvinyl chloride and their copolymers, polypropylene, tetrafluoroethylene and trifluoro chloroethylene, as exemplified by sheets of polyethylene and polypropylene 0.002 inch thick which will transmit oxygen and are therefore suitable for use with aerobic micro-organisms, and sheets of 0.006 inch thickness or laminated thinner sheets for anaerobic micro-organisms; where aerobic micro-organisms are to be cultured, either the entire casing or only one face thereof may be made of plastic material which transmits oxygen. The wick may be of commercial cotton twill tape 0.25 inch by 0.007 inch (preferred), filter paper or cloth, wet strength paper towelling, fibre glass tape, cotton ribbon, and cotton twill or cross grain ribbon. Ingredients for the culture medium include peptones, sugars (specified), sodium chloride, potassium hydrogen phosphate, gelatin, agaragar, serum, blood, specified proprietary preparations and brom cresol purple indicator. After the casing has been made and the culture medium inserted into the compartments, the assembly is sterilized, e.g. by autoclaving at 121 DEG C. for 20 minutes, radiation or immersion in an atmosphere of ethylene oxide. Examples are directed to the culturing of Clostridium welchii and Lactobacillus acidophilus.