MICROBIOLOGY LECTURE:CYANOBACTERIA

1. GENERAL CHARACTERISTICS -THOUSANDS OF SPECIES -600 MILLION YRS. OLD, FOSSIL EVIDENCE -FORMERLY CALLED “BLUE-GREEN ALGAE

A. PROKARYOTE -NO INTERNAL STRUCTURES -SMALL COMPARED TO EUKARYOTES -CELL FUNCTIONS OCCUR IN CYTOPLASM RESPIRATION MOSTLY NEAR CELL MEMBRANE -

. -CHEMICAL ANALYSIS: IDENTICAL TO PHOTO-SYNTHETIC BACTERIA, COMPLETELY DIFFERENT FROM EUKARYOTIC ALGAE

B. NUTRITION -AUTOTROPHIC: CHLOROPHYLL CAN BE MANY COLORS, MOST COMMON SPECIES HAVE BLUE GREEN CHLOR. CONTAINING CYANIDE “FIX” NITROGEN: NO 2 CONVERTED TO NH 3 NATURAL SOURCE OF “NITROGEN” FOR PROTEINS

C. MORPHOLOGY -UNICELLULAR & IN FILAMENTS -SOME HAVE GELATINOUS SHEATH (TOXIC?) -NO FLAGELLA, BUT SOME CAN GLIDE -COLOR PIGMENTS: CAROTENE, ERYTHRIN

. -OIL BUBBLES: FOOD STORAGE & FLOTATION -HETEROCYSTS: LOOK EMPTY BUT NITROGEN “FIXING”

ENDOSPORES: SURVIVAL TECHNIQUE

D. HABITAT -ANYPLACE WITH WATER AND LIGHT -SPECIES ADAPTED TO ALL ENVIRONMENTS -UNIQUELY RESISTANT TO EXTREMES OF pH, TEMPERATURE, CHEMICALS -PRODUCE OIL WHICH FOULS LAKES, PONDS(PETROLEUM?), SMELLS VERY BAD -SOME PRODUCE POISONS HARMING FISH & ANIMALS

E. REPRODUCTION -ASEXUAL ONLY – BINARY FISSION

F. EXAMPLES -POLYCYSTIS, GLEOCAPSA, OSCILLATORIA, NOSTOC, ANABENA & LYNGBYA