LSCI 230 Lecture Notes - Lecture 11: Azotobacter Vinelandii, Salmonella Enterica Subsp. Enterica, Azotobacter
24 Dec 2018
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Lab 8 soil: many microhabitats lead to a lot of microbial diversity, bacteria, actinomycetes, fungi. A count of each organism per gram of soil was conducted. Actinomycete colonies are capable of producing metabolites that inhibit the growth of other organisms like s. aureus of b. subtilis. Ammonification: peptone and casein solutions inoculated with soil, nessler"s reagent yellow/brown = ammonia. Nitrogen fixation-free living: azotobacter vinelandii, aerobe, azotobacter agar, clostridium spp, anaerobe, tube of n-free broth, gram positive, endospores. Heterotrophic plate count (aerobic: 1ml and 0. 1 ml samples of 1:100 diluted raw water was plated (pour method, colony forming units were determined. Staphylococci carrier state: s. aureus: scalded skin syndrome, impetigo, meningitis, urinary tract infections, food poisoning, s. epidermidis: less invasive, small abscesses, pathogen= black colonies with white precipitate. Slidex staph kit: 1 drop of s. aureus reagent and separately 1 drop control reagent, mix 1 colony with each reagent, positive for s. aureus = agglutination of blue granules within 30 seconds.
