Prokaryotes lack membrane bound nucleus Bacteria and Archaea most abundant life forms on earth living systems would collapse without them oldest prokaryote fossils about 3 8 bya prokaryotic fossils show lipids Prokaryote structure simple morphology does not differ between Bacteria and Archaea 1 Bacillus rod shaped 2 Coccus round spherical 3 Spirillium spiral helix Can form colonies filaments groupings of individual cells A and B differ in lipids proteins in their plasma membranes Bacteria lipids have ester bonds Archaea lipids have ether bonds more stable don t break down as easily as ester bonds connecting Glycerol with fatty acid tails A and B differ in terms of cell walls Bacteria have a lot of Peptidoglycan in cell wall Archaea have no Peptidoglycan Peptidoglycan affects what substances Bacteria will take in Genetic machinery associated with protein productions differs A same as used by eukaryotes have introns alters patterns of gene expression alters protein production B unique simple protein production system lack introns Archaea found everywhere normal conditions and extreme conditions Extremophiles no parasitic or pathogenic forms symbiotes mutualists interaction and or commensalists 0 Thermophiles 140 175 degrees F hot springs deep sea thermal vents have heat stable enzymes Thermus aquaticus found in Yellowstone have Taq polymerase PCR polymerase chain rxn single DNA piece can be amplified into millions of copies deep sea thermal vents very very high temps loaded with hydrogen sulfide Archaea metabolize hydrogen sulfide to gain energy Pyrococcus furiosus optimal temperature 100 degrees C enzymes contain tungsten heat stability Acidophiles found below pH of 2 pine forests bogs acid mine drainage orange streams PA OH Wales food yogurt buttermilk sour cream Halophiles found in very high levels of salinity optimal growth at 40 salinity Great Salt Lake Dead Sea soy sauce sauerkraut cytoplasm is loaded with proteins high protein content reduces salt influx and water loss maintain osmotic pressure genes of halophiles are being inserted into genomes of agricultural crops crops can grow in salty soil Methanogens produce methane a greenhouse gas wetlands are loaded with methanogens cattle digestive tracts garbage dumps methane used as biogas and for power production termites digestive tracts all methane in these areas produced by archaea not the area itself Bacteria most basic way to separate or characterize bacteria is cell wall structure gram staining gram pos gram neg shows biochemical composition of cell wall indicates environmental tolerances indicates food source toxin susceptibility thick cell wall loaded with peptidoglycan Gram Positive Bacteria purple stain Gram Negative Bacteria two layers to cell wall inner layer is peptidoglycan thin outer is typical lipid bilayer membrane composed of lipopolysaccharides and porin determine what goes in out of cell recognition of food toxins porin blocks purple stain peptidoglycan remains unstained further steps in gram staining protocol bypass porin barrier peptidoglycan stains pink stain or red Because of outer membrane gram negative are less susceptible to antibiotics toxins Gram Positive Bacteria Phylum Actinobacteria common soil bacteria Nodule forming actinobacteria nodule swelling on plant root nodule filled with bacteria symbiosis mutualism bacteria gain structure shelter carbon for growth reprod plants gain nitrogen fertilizer bacteria are N fixers convert atmospheric nitrogen into NH4 fertilizer growth and reprod Actinobacteria on teeth biofilm aggregation of bact Archaea fungi algae viruses in a polysaccharide matix dental plaque lots of Actinobacteria Many actinobacteria produce anti fungal or antibiotic compounds streptomycin tetracycline very expensive energetically protects them from fungi bacteria reduces competition for food space Soil bacteria used to treat heavy metal contamination bioremediation using bacteria that eat bad things to clean up oil spills Mycobacterium tuberculosis bacteria results in tuberculosis lung infection can be fatal Mycobacterium leprae leprosy bacteria cause skin lesions major nerve damage damage mucosal linings Phylum Firmicutes Bacillus thuringiensis Bt insecticidal bacterium deadly to insects used in biological control of agricultural pests insects Bt carries toxic crystals when ingested by insects leads to death Thuricide uses crystals and spores chemical taking genes associated with toxin cry genes and engineering them into plant genome Bacillus anthracis anthrax found everywhere in soil grazing animal disease usually deadly when humans get it Streptococcus and Staphylococcus Strepto strep throat scarlet fever meningitis Staph skin infections respiratory infections often commensals symbiosis 0 bacteria benefits host unaffected become pathogens under right conditions Ex Streptococcus pneumoniae ear infection Amycolatopsis orientalis actinobacteria Vancomycin treated previous Ex Staphylococcus aureus MRSA methicillin resistant mult drug Gram Negative Bacteria Phylum Spirochaeta spiral helix based morphology common in wet environments water blood Trepoema syphallus Borrelia burgdorferi Bb Lyme disease spread by deer tick reservoir carrier good rains high plant growth increased reprod oak trees inc acorns inc mice and deer pops inc hosts inc tick numbers inc infection rate inc human contact Phylum Cyanobacteria aquatic bacteria photosynthetic Microcystis produces toxin microcystin kills organisms toxin is produced to reduce competition nitrogen fixers Phylum Proteobacteria largest most diverse phylum found everywhere alpha beta gamma groupings based on physiological characteristics metabolism environmental tolerances T moisture Escherichia coli E coli gamma Proteobacteria found primarily in mammalian gastrointestinal tracts critical to effective digestion common in sewage waste water polluted water fecal coliforms E coli from feces also found in natural streams rivers best studied of all bacteria many different strains each has unique characteristics coded by unique gene sequences extraordinarily genetically diverse along with helpful gut bacteria there are many harmful strains E coli 0157 H7 undercooked red meat contaminated veggies fruits Wolbachia the male killer intracellular proteobacteria that is very similar to mitochondria found only in insect reproductive cells 25 of all insect species inherited passed to offspring Mechanisms of removing males some kill males in utero before birth
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