mochi

The possible bacteria in unknown vial are: Gram positive: Bacillus cereus C. Xerosis Enterococcus faecalis Lactococcus lactis Micrococcus luteus Staphylococcus aureus Staphylococcus epidermidis Gram negative: E. coli E. aerogenes P. vulgaris P. fluorescens P. aeruginosa The professor narrowed it down a bit for us. So there is only gram negative bacilli. @VictorMedvil Wait, I thought gram + stained purple and gram - stained pink...?

This experiment is for my microbiology lab class... not sure if it could be coccobacilli... If it is a type of bacilli, it does not ferment lactose on the MacConkey Agar. This means (from the flow-chart), that it must be either: P. vulgaris, P. rettgeri, P. mirabilis, P. inconstans, P. aeruginosa, P. fluorescens, or P. mallei. I am doing a methyl red test also to see if it ferments glucose, but I haven't seen the results yet.

This first picture shows a gram stain of 2 unknown bacteria (one is gram +, and one is gram -). At first, it appeared that both the gram positive and gram negative bacteria were cocci. I then isolated the gram + from the gram - by plating on a phenylethyl alcohol agar and a MacConkey Agar. But the next pictures seem to show the gram negative bacteria (on the MacConkey Agar) to be bacilli...? What do you guys think these bacteria are? I'm pretty much positive that the gram positive bacteria is cocci, but I'm not sure about the gram negative... :/ Thanks for your help!!! This is the gram + unknown bacteria (plated on the phenylethyl alcohol agar). I'd say this is definitely cocci. This is the gram - unknown bacteria (plated on the MacConkey Agar). This picture makes it look like bacilli... but it was hard to tell if it really was under the microscope. The first picture showed the gram - bacteria looking like cocci... I'm not really sure what it is... Do you guys know if the gram - is cocci or bacilli? Thanks!