Culture media for the enumeration of Bifidobacterium bifidum and Lactobacillus acidophilus in the presence of yoghurt bacteria

VINDEROLA, C.G.; REINHEIMER, J.A.

INTERNATIONAL DAIRY JOURNAL

ELSEVIER SCI LTD

Año: 1999 vol. 9 p. 497 - 505

0958-6946

A proposed methodology for the enumeration of probiotic bacteria (bi"dobacteria and Lactobacillus acidophilus) in the presence of yoghurt bacteria is described. Commercial mixed cultures of yoghurt (four cultures), L. acidophilus (two cultures) and Bixdobacterium bixdum (two cultures) were assayed using a total of 15 culture media from four agar categories: nonselective (Skim Milk (SM), MRS and M17); modi"ed (Galactose MRS (G-MRS), Galactose M17 (G-M17) and Trehalose MRS (T-MRS)); di!erential (Lactic Bacteria Di!erential (LBD), Lactic- and L-S); and selective (Nalidixic Paromomycin Neomycin Lithium MRS (NPNL-MRS), Nalidixic Neomycin Lithium MRS (NNL-MRS), Nalidixic Kanamycin Lithium MRS (NKB-MRS), Bile-MRS, Oxgall Gentamicin MRS (OG-MRS) and Lithium Propionate MRS (LP-MRS)). Every culture used was tested for its growth on each medium under three di!erent incubation conditions (aerobic, anaerobic with combustion and anaerobic in GasPak) at 373C for 72 h. SM and MRS agar were taken as reference media for yoghurt and probiotic bacteria, respectively. For each organism, the cell recovery rate on each medium was compared statistically with that obtained on the reference media. The ability of every medium to di!erentiate or inhibit the organisms was also tested. SM and LBD agar (aerobic) were useful to enumerate yoghurt bacteria and inhibit bi"dobacteria. T-MRS and Bile-MRS agar (aerobic) only allowed the growth of L. acidophilus cultures. For Bixdobacterium bixdum, a selective count could be performed on LP-MRS agar (anaerobic, GasPak). This set of media was demonstrated to be e!ective for the enumeration of"dobacteria and Lactobacillus acidophilus) in the presence of yoghurt bacteria is described. Commercial mixed cultures of yoghurt (four cultures), L. acidophilus (two cultures) and Bixdobacterium bixdum (two cultures) were assayed using a total of 15 culture media from four agar categories: nonselective (Skim Milk (SM), MRS and M17); modi"ed (Galactose MRS (G-MRS), Galactose M17 (G-M17) and Trehalose MRS (T-MRS)); di!erential (Lactic Bacteria Di!erential (LBD), Lactic- and L-S); and selective (Nalidixic Paromomycin Neomycin Lithium MRS (NPNL-MRS), Nalidixic Neomycin Lithium MRS (NNL-MRS), Nalidixic Kanamycin Lithium MRS (NKB-MRS), Bile-MRS, Oxgall Gentamicin MRS (OG-MRS) and Lithium Propionate MRS (LP-MRS)). Every culture used was tested for its growth on each medium under three di!erent incubation conditions (aerobic, anaerobic with combustion and anaerobic in GasPak) at 373C for 72 h. SM and MRS agar were taken as reference media for yoghurt and probiotic bacteria, respectively. For each organism, the cell recovery rate on each medium was compared statistically with that obtained on the reference media. The ability of every medium to di!erentiate or inhibit the organisms was also tested. SM and LBD agar (aerobic) were useful to enumerate yoghurt bacteria and inhibit bi"dobacteria. T-MRS and Bile-MRS agar (aerobic) only allowed the growth of L. acidophilus cultures. For Bixdobacterium bixdum, a selective count could be performed on LP-MRS agar (anaerobic, GasPak). This set of media was demonstrated to be e!ective for the enumeration ofL. acidophilus (two cultures) and Bixdobacterium bixdum (two cultures) were assayed using a total of 15 culture media from four agar categories: nonselective (Skim Milk (SM), MRS and M17); modi"ed (Galactose MRS (G-MRS), Galactose M17 (G-M17) and Trehalose MRS (T-MRS)); di!erential (Lactic Bacteria Di!erential (LBD), Lactic- and L-S); and selective (Nalidixic Paromomycin Neomycin Lithium MRS (NPNL-MRS), Nalidixic Neomycin Lithium MRS (NNL-MRS), Nalidixic Kanamycin Lithium MRS (NKB-MRS), Bile-MRS, Oxgall Gentamicin MRS (OG-MRS) and Lithium Propionate MRS (LP-MRS)). Every culture used was tested for its growth on each medium under three di!erent incubation conditions (aerobic, anaerobic with combustion and anaerobic in GasPak) at 373C for 72 h. SM and MRS agar were taken as reference media for yoghurt and probiotic bacteria, respectively. For each organism, the cell recovery rate on each medium was compared statistically with that obtained on the reference media. The ability of every medium to di!erentiate or inhibit the organisms was also tested. SM and LBD agar (aerobic) were useful to enumerate yoghurt bacteria and inhibit bi"dobacteria. T-MRS and Bile-MRS agar (aerobic) only allowed the growth of L. acidophilus cultures. For Bixdobacterium bixdum, a selective count could be performed on LP-MRS agar (anaerobic, GasPak). This set of media was demonstrated to be e!ective for the enumeration ofxdum (two cultures) were assayed using a total of 15 culture media from four agar categories: nonselective (Skim Milk (SM), MRS and M17); modi"ed (Galactose MRS (G-MRS), Galactose M17 (G-M17) and Trehalose MRS (T-MRS)); di!erential (Lactic Bacteria Di!erential (LBD), Lactic- and L-S); and selective (Nalidixic Paromomycin Neomycin Lithium MRS (NPNL-MRS), Nalidixic Neomycin Lithium MRS (NNL-MRS), Nalidixic Kanamycin Lithium MRS (NKB-MRS), Bile-MRS, Oxgall Gentamicin MRS (OG-MRS) and Lithium Propionate MRS (LP-MRS)). Every culture used was tested for its growth on each medium under three di!erent incubation conditions (aerobic, anaerobic with combustion and anaerobic in GasPak) at 373C for 72 h. SM and MRS agar were taken as reference media for yoghurt and probiotic bacteria, respectively. For each organism, the cell recovery rate on each medium was compared statistically with that obtained on the reference media. The ability of every medium to di!erentiate or inhibit the organisms was also tested. SM and LBD agar (aerobic) were useful to enumerate yoghurt bacteria and inhibit bi"dobacteria. T-MRS and Bile-MRS agar (aerobic) only allowed the growth of L. acidophilus cultures. For Bixdobacterium bixdum, a selective count could be performed on LP-MRS agar (anaerobic, GasPak). This set of media was demonstrated to be e!ective for the enumeration of"ed (Galactose MRS (G-MRS), Galactose M17 (G-M17) and Trehalose MRS (T-MRS)); di!erential (Lactic Bacteria Di!erential (LBD), Lactic- and L-S); and selective (Nalidixic Paromomycin Neomycin Lithium MRS (NPNL-MRS), Nalidixic Neomycin Lithium MRS (NNL-MRS), Nalidixic Kanamycin Lithium MRS (NKB-MRS), Bile-MRS, Oxgall Gentamicin MRS (OG-MRS) and Lithium Propionate MRS (LP-MRS)). Every culture used was tested for its growth on each medium under three di!erent incubation conditions (aerobic, anaerobic with combustion and anaerobic in GasPak) at 373C for 72 h. SM and MRS agar were taken as reference media for yoghurt and probiotic bacteria, respectively. For each organism, the cell recovery rate on each medium was compared statistically with that obtained on the reference media. The ability of every medium to di!erentiate or inhibit the organisms was also tested. SM and LBD agar (aerobic) were useful to enumerate yoghurt bacteria and inhibit bi"dobacteria. T-MRS and Bile-MRS agar (aerobic) only allowed the growth of L. acidophilus cultures. For Bixdobacterium bixdum, a selective count could be performed on LP-MRS agar (anaerobic, GasPak). This set of media was demonstrated to be e!ective for the enumeration of!erential (LBD), Lactic- and L-S); and selective (Nalidixic Paromomycin Neomycin Lithium MRS (NPNL-MRS), Nalidixic Neomycin Lithium MRS (NNL-MRS), Nalidixic Kanamycin Lithium MRS (NKB-MRS), Bile-MRS, Oxgall Gentamicin MRS (OG-MRS) and Lithium Propionate MRS (LP-MRS)). Every culture used was tested for its growth on each medium under three di!erent incubation conditions (aerobic, anaerobic with combustion and anaerobic in GasPak) at 373C for 72 h. SM and MRS agar were taken as reference media for yoghurt and probiotic bacteria, respectively. For each organism, the cell recovery rate on each medium was compared statistically with that obtained on the reference media. The ability of every medium to di!erentiate or inhibit the organisms was also tested. SM and LBD agar (aerobic) were useful to enumerate yoghurt bacteria and inhibit bi"dobacteria. T-MRS and Bile-MRS agar (aerobic) only allowed the growth of L. acidophilus cultures. For Bixdobacterium bixdum, a selective count could be performed on LP-MRS agar (anaerobic, GasPak). This set of media was demonstrated to be e!ective for the enumeration of!erent incubation conditions (aerobic, anaerobic with combustion and anaerobic in GasPak) at 373C for 72 h. SM and MRS agar were taken as reference media for yoghurt and probiotic bacteria, respectively. For each organism, the cell recovery rate on each medium was compared statistically with that obtained on the reference media. The ability of every medium to di!erentiate or inhibit the organisms was also tested. SM and LBD agar (aerobic) were useful to enumerate yoghurt bacteria and inhibit bi"dobacteria. T-MRS and Bile-MRS agar (aerobic) only allowed the growth of L. acidophilus cultures. For Bixdobacterium bixdum, a selective count could be performed on LP-MRS agar (anaerobic, GasPak). This set of media was demonstrated to be e!ective for the enumeration of!erentiate or inhibit the organisms was also tested. SM and LBD agar (aerobic) were useful to enumerate yoghurt bacteria and inhibit bi"dobacteria. T-MRS and Bile-MRS agar (aerobic) only allowed the growth of L. acidophilus cultures. For Bixdobacterium bixdum, a selective count could be performed on LP-MRS agar (anaerobic, GasPak). This set of media was demonstrated to be e!ective for the enumeration of"dobacteria. T-MRS and Bile-MRS agar (aerobic) only allowed the growth of L. acidophilus cultures. For Bixdobacterium bixdum, a selective count could be performed on LP-MRS agar (anaerobic, GasPak). This set of media was demonstrated to be e!ective for the enumeration ofL. acidophilus cultures. For Bixdobacterium bixdum, a selective count could be performed on LP-MRS agar (anaerobic, GasPak). This set of media was demonstrated to be e!ective for the enumeration of!ective for the enumeration of S. thermophilus, Lactobacillus delbrueckii subsp. bulgaricus, L. acidophilus and Bixdobacterium bixdum in commercial dairy products., Lactobacillus delbrueckii subsp. bulgaricus, L. acidophilus and Bixdobacterium bixdum in commercial dairy products.