Working with _Serratia marcescens

Serratia marcescens is a gram-negative pathogenic bacteria known for its distinctive red pigmentation. While it is not found in the microbiome of healthy honey bees (Apis mellifera), it is capable of living in the gut of sick or aging bees. S. marcescens can be cultured in vitro.

In vitro culture conditions

Both strains of S. marcescens used in the Barrick lab, N10A48 an KZ2, grow robustly in LB after 24 hours at 30°C. S. marcescens will form colonies on LB agar after 24 hours at 30°C. S. marcescens has some natural tolerance for spectinomycin. When working with spectinomycin-resistant S. marcescens, the working concentration of spectinomycin should be increased from 60 mg/mL to 180 mg/mL for this reason.

Isolating plasmid DNA ("Miniprep")

S. marcescens N10A48 and KZ2 do not pellet well after lysis when isolating plasmid DNA. Instead of forming a neat pellet, cell debris forms a gelatinous blob that makes it difficult to remove the supernatant. Increasing the speed and time of the centrifugation step to 15000x for 20 minutes helps form a more compact pellet.

-- Main.StrattonGeorgoulis - 14 Dec 2017