Isolation of lactobaciulus
I think my favorite fact from writing about all these gross things that are in our bodies was the idea that our bacteria:human cell ratio is 10:1 -- some are harmless, some are harmful, and some are just waiting around for you to die so they can finally have a good meal.
A healthy human body is actually less human than you might think; as an adult, your body is hosting at least 10 times as many microbial cells (that's bacteria, viruses and other types of microbes) as you have human cells -- probably about 100 trillion bacteria in all [source: The Human Microbiome Project Collection, Zimmer]. And they live in every nook and cranny of your body.
Fewer than 1 percent of the bacteria in the human body can cause disease or illness, and others work with the body to help it do things it may not have been able to do on its own -- for instance, Lactobacillus acidophilus, a popular active culture in yogurt, helps the body digest food and fight against that 1 percent of ill-willed microbes.
Como isolar, separar lactobacilos ¿Qué se necesita ?
MRS agar From Wikipedia
A menudo abreviado como MRS, este tipo de medio de cultivo bacteriano es llamado así por sus inventores: De Man, Rogosa y Sharpe. Desarrollado en 1960, este medio fue diseñado para favorecer el crecimiento exuberante de Lactobacilli para el estudio de laboratorio. Contiene acetato de sodio, que suprime el crecimiento de muchas bacterias que compiten (aunque algunos otros Lactobacillales, como Leuconostoc y Pediococcus, pueden crecer). Este medio tiene un color marrón claro 
MRS agar typically contains (w/v):
1.0 % peptone 0.8 % egg extract 0.4 % yeast extract 2.0 % glucose 0.5 % sodium acetate trihydrate 0.1 % polysorbate 80 (also known as Tween 80) 0.2 % dipotassium hydrogen phosphate 0.2 % triammonium citrate 0.02 % magnesium sulfate heptahydrate 0.005 % manganese sulfate tetrahydrate 1.0 % agar pH adjusted to 6.2 at 25°C
The yeast and meat extracts and peptone provide sources of carbon, nitrogen and vitamins for general bacterial growth. The yeast extract also contains vitamins and amino acids specifically required by Lactobacilli. Polysorbate 80 is a surfactant which assists in nutrient uptake by Lactobacilli. Magnesium sulfate and manganese sulfate provide cations used in metabolism.
Principles of the Procedure Oxbile is used as a selective agent for the isolation of Gram-negative microorganisms, inhibiting Gram-positive bacteria. The major composition of Oxbile is taurocholic and glycocholic acids.
ahhhh creo que esto es lo mejor y más barato esperemos que funcione
Bromocresol purple (BCP) or 5',5"-dibromo-o-cresolsulfophthalein, is a pH indicator. In its sultone form, it has a pKa value of 6.3, and is usually prepared as a 0.04% aqueous solution. Bromocresol purple (pH indicator)
below pH 5.2 above pH 6.8 5.2 ⇌ 6.8
Besides its primary function as an indicator, bromocresol purple is used in medical laboratories to measure albumin, and as an addition to acid stop baths used in photographic processing as an indicator that the bath has reached neutral pH and needs to be replaced.
The swabs were inoculated onto MRS agar plates (Difco) and incubated at 37°C with partial CO2 tension for 48 h. Growth on MRS was observed for 21 of the 105 analysed samples, and one or more colonies were selected and picked for each of the 21 samples. All colonies were examined by Gram staining and catalase and oxidase tests. A total of 31 strains that were phenotypically consistent with the Lactobacillus genus were chosen and preserved in 25% MRS glycerol at −70°C until DNA extraction.
pep·tone (pĕp′tōn′)n. Any of various water-soluble protein derivatives obtained by partial hydrolysis of a protein by an acid or enzyme during digestion and used in culture media in bacteriology.
- EMD Chemicals, MRS Agar, 2002.