US 12,391,907 B2
Water-reconstitutable culture medium resistant to liquefaction by microorganisms
Jason W. Bjork, Woodbury, MN (US); and Sailaja Chandrapati, Woodbury, MN (US)
Assigned to Neogen Food Safety US HoldCo Corporation, Lansing, MI (US)
Appl. No. 16/771,866
Filed by NEOGEN FOOD SAFETY US HOLDCO CORPORATION, Lansing, MI (US)
PCT Filed Dec. 12, 2018, PCT No. PCT/IB2018/059939
§ 371(c)(1), (2) Date Jun. 11, 2020,
PCT Pub. No. WO2019/116259, PCT Pub. Date Jun. 20, 2019.
Claims priority of provisional application 62/597,961, filed on Dec. 13, 2017.
Prior Publication US 2020/0399574 A1, Dec. 24, 2020
Int. Cl. C12M 1/00 (2006.01); C08L 1/28 (2006.01); C12M 1/12 (2006.01); C12N 5/00 (2006.01); G05F 1/59 (2006.01); H02M 3/157 (2006.01); H02M 3/158 (2006.01); H02M 1/00 (2006.01)
CPC C12M 23/20 (2013.01) [C08L 1/284 (2013.01); C12M 23/04 (2013.01); C12N 5/0068 (2013.01); G05F 1/59 (2013.01); H02M 3/157 (2013.01); H02M 3/1584 (2013.01); H02M 1/0012 (2021.05)] 8 Claims
 
1. A device for growing microorganisms, comprising:
i. a body member comprising a self-supporting, water-proof substrate having upper and lower surfaces, a layer of adhesive, and a cold-water-soluble powder;
wherein said layer of adhesive is disposed on said upper surface of said substrate;
wherein said adhesive is non-inhibitory to the growth of microorganisms;
wherein said cold-water-soluble powder comprises guar gum and hydroxypropylmethylcellulose and one or more nutrients for growing microorganisms;
wherein said cold-water-soluble powder is adhered to said adhesive, where said hydroxypropylmethylcellulose and said guar gum are present in said cold-water-soluble powder at a mass ratio in the range of one part of said hydroxypropylmethylcellulose to one part of said guar gum to three parts of said hydroxypropylmethylcellulose to one part of said guar gum; and
ii. a cover sheet having an inner-facing surface and an outer-facing surface, comprising a dry composition and a layer of adhesive;
wherein said adhesive is adhered to the inner-facing surface of said cover sheet;
wherein said dry composition comprises a mixture of hydroxypropylmethylcellulose and guar gum;
wherein said dry composition is adhered to said inner-facing surface of said cover sheet;
wherein said device includes a microbial growth zone between said substrate and said cover sheet;
wherein said microbial growth zone is free of matrices that prevent visualization of bacterial colonies;
wherein said cover sheet is adhered to said body member so that the upper surface of said substrate faces said inner-facing surface of said cover sheet; and
wherein said hydroxypropylmethylcellulose and said guar gum are present in said dry composition at a mass ratio in the range of one part of said hydroxypropylmethylcellulose to one part of said guar gum to three parts of said hydroxypropylmethylcellulose to one part of said guar gum.