Purple Non Sulfur Bacteria

Hopkins Microbiology CourseAnn Lesnefsky 7-15-2011

Metabolism of PNS Bacteria

• Organic acid electron donor• Photosynthesis for energy

generation– Bacterial chlorophyll b– Absorbs light in the infrared

range

• Currently PNS bacteria are being studied for H2 production

Course Enrichment Method for PNS

• 6-18-2011– Plated samples from the slough on succinate and

ethanol plates, incubated anaerobically with light– Course’s media and Holly’s media

• 6-29-2011– Restreak single colonies for isolation

TA Enrichment Method for PNS

• TA’s enriched for PNS by filtering– Filter both water above mat and

slurry of mat material– Place filter face down on plate– Flip and all allow PNS bacteria to

grow on filter

Carbon Source

Enrichment Method

Succinate (# of colonies before restreak)

Ethanol (# of colonies before restreak)

No filter Course

43 6

Holly

0 0

Filter Course

Many

Some

Holly

Few None

Microscopy of PNS• Colonies isolated from 5 different plates– 4 plates from strawberry– 1 from Kerby Park

• All looked like stubby rods

Recommendations

• Next year use the filter method.

Questions?