PENGHITUNGAN JUMLAH SEL BAKTERI DENGAN METODE MOST PROBABLE NUMBER (MPN)

Abstract

Bacterial growth is referred to addition of cell mass total. MPN method can count microorganism. MPN is quantitative analysis method for determining MPN of microorganism in sample. Purpose of this practice is study cell counting technique and analyze water quality microbiologically depends on MPN (most probable number) method. Practice was held on Tuesday, May 2, 2017 in 07.30-11.05 WIB at Microbiology Laboratory, Department of Biology, Faculty of Mathematics and Natural Science, University of Brawijaya Malang. Method use in this practice is inoculating sample to some medium. Media used for presumptive test is single lactose broth and double lactose broth, for confirmation test is BGLBB (Brilliant Green Lactose Bile Broth), and completed test is EMB agar (Eosin Methylene Blue). Bacteria growth in media then incubated for determined times and temperature. Water are collected from well water, boiled water, and jamu gendong. Result of this practice is well water contain nonfecal coliform bacteria which mark as clear colorant in EMB agar and fecal coliform bacteria which mark as green metalic colorant in EMB agar. Boiled water is not containing any coliform bacteria after tested using confirmation test and completed test. Jamu gendong water containing fecal bacteria which mark as green metalic colorant in EMB agar, Result of Gram staining for green colorant bacteria in EMB agar is bacil and Gram negative bacteria so guessed as E. coli