Naming of the Bacillus isolated from raw milk and the evaluation of biofilm presence

In this study 50 raw milk samples collected from milk enterprises in Ankara and neighboring provinces between September 2010 - April 2011 were studied as the material. After Bacillus isolation of 50 specimens descriptions of them in levels of species were performed by BBL Crystal Identification System Gram-Positive ID Kit. In addition, biochemical tests (catalase, indole, citrate, triple sugar iron (TSI), Voges Proskauer (VP), urea) were studied. As a result, from 50 raw milk samples 109 Bacillus were isolated. From 109 Bacillus, 11 Bacillus licheniformis, 22 B.subtilis, 14 B.macerans, 4 B.stearothermophilus, 20 B.brevis, 1 B.pumilus, 2 B.cereus, 1 B.lentus, 1 B.megaterium, 5 B.polymyxa, 6 B.coagülans and 22 B.ssp were named.In addition the presences of biofilm were investigated in the isolates named in species level. In study of biofilms using the crystal violet dye, values obtained at the end of 24 hours and 48-hour period were read in the spectrophotometer at a wavelength of 540 nm. As a result of spectrophotometric evaluation of 24 hours from the total of 109 isolates, 105 (96,3%) were found biofilm possitive and 4 (3,7%) were found negative biofilm.From 105 isolates that detected biofilm presence, 19 (18,10%), B.subtilis, 20 (19,05%) B.brevis, 10 (9,52%) B.licheniformis, 2 (1,90%), Bacillus cereus, 1 (0,95%) B.megaterium, 1 (0,95%) B.pumilus, 4 (3,82%) B.stearothermophilus, 1 (0,95%) B.lentus, 14 (13,34%) B.macerans, 5 (4,76%) B.polymyxa, 6 (5,71%) B.coagülans, 22 (20,95%) B.ssp were found.Key words : Bacillus, biofilm, raw milk