Yeast Dextrose Fructose Galactose strains Color Gas Color Gas Color Gas DY5 Yellow +++ Yellow ++ Yellow ++ DPSW Yellow +++ Orange ++ Yellow ++ MUR3B Yellow +++ Yellow +++ Yellow +++ ENG Yellow ++ Yellow ++ Yellow + SUG1 Yellow +++ Yellow +++ Yellow ++ FAPW Orange + Orange - Orange ++ JAK3 Orange - Orange + Yellow +++ SUGW Yellow ++ Orange + Orange - Yeast Maltose Sucrose strains Color Gas Color Gas DY5 Yellow +++ Yellow +++ DPSW Yellow ++ Yellow +++ MUR3B Yellow +++ Yellow +++ ENG Orange ++ Yellow +++ SUG1 Yellow +++ Yellow +++ FAPW Orange ++ Yellow - JAK3 Yellow + Orange + SUGW Yellow +++ Yellow ++ +: <one-third of Durham tube; ++: greater than one-third and [less than or equal to] two-thirds of Durham tube; +++: greater than two-thirds; -: no gas production.
The Durham tubes were also placed into the media to trap the carbon dioxide released.
The carbohydrate utilization test was performed using broth (peptone: 10 g; NaCl: 5 g; phenol red: 0.018 g; distilled water: 1000 ml; carbohydrate: 10 g) along with inverted Durham tubes in the broth.
This experiment was conducted through 3-tube MPN1 method according to existing standards, both by Durham tube
to analyze coliform bacteria and without Durham tube
for general microbial analysis (14).
In order to check Escherichiacoli, part of the purple colonies with a diameter of 0.5 mm were transferred to tubes containing lactose broth along with Durham tube and were placed in incubator at 37[degrees]C for 24 h.
Microorganisms were investigated in terms of concentration of gas (carbon dioxide) in the Durham tube. Also biochemical tests IMVIC were investigated after the incubation at 37[degrees]C for 48-24 hours.
"This site was previously known as the Brookside works, belonging to the Durham Tube
company," said Steve.
Took a loopful of culture from the EMB agar streaking petriplates and inoculated it into 9 ml of sterilized MacConkey broth in test tubes containing inverted Durham tubes
. Then incubated the test tubes at 37degC for 24 hours.
Three serial dilutions of 1 ml, 0.1 ml and 0.01 ml were inoculated in lauryle sulphate tryptose broth (g/L; Tryptose 20, Lactose 5.0, K2HPO4 2.75, KH2PO4 2.75, NaCl 5, Sodium lauryle sulphate 0.1) of OXOID, UK taken in test tubes with inverted Durham tubes. These tubes were incubated at 35degC for 24-48 hours for presumptive test.
31.5, Di-Potassium phosphate 4.0, Manose potassium phosphate 1.5, NaCl 5.0, pH 6.9 +- 0.2) of OXOID, UK again with inverted Durham tubes for the indication of gas production, were incubated at 35 +- 0.5 degC and 44.5 +- 0.2 degC for 24-48 +-03 hours for the confirmation of total and fecal coliform bacteria respectively.
Fifteen culture tubes were used per sample; five tubes contained 10 ml double strength and the remaining ten contained 5 ml single strength MacConkey broth (Oxoid CM5a) with inverted Durham tubes
. Each bottled water sample was shaken vigorously to obtain a homogenous dispersion of microorganisms and the bottle necks sterilized with 70% alcohol.