Reduction of Bacillus cereus sensulato Biofilms on Stainless Steel Surfaces by Pestalotiopsis sp. Culture Crude Extract

The biofilm formation of fourBacillus cereus sensulato isolates was induced on milk pre-soiled stainless steel coupons (20 5 mm) under nutrient-depleted broth medium for a total of 48 h. Biofilms on these coupons were immersed for 15 min in 25, 50, or 100 mg/mL of Pestalotiopsis sp. (P-03) culture crude extract at 25 or 50C. Results showed that the biofilm cells were significantly reduced (p less than 0.05) as compare to nontreated biofilms after immersion in 50 and 100 mg/mL of P-03 crude extract, which the most significant was found at 100 mg/mL with 2-Log reduction (99 %). The crude secondary metabolites obtained from P-03 fermentation broth cultures were detected through thin layer chromatography. Pestalotiopsis spp. hasfound to produce novel secondary metabolites with a wide range of bioactivities. Additionally, fluorescence micrographs were supplemented and showed decreasing light intensities emitted by the fluorescent dye ethidium bromide at 605 nm. The interactive 3-D surface plots, which generated using ImageJ 1.52a software, indicated that the extracellular matrix was disrupted. This study concluded that the unknown secondary metabolites from P-03 crude extract have antibiofilm activity against B. cereus s. l. biofilms on stainless steel surfaces and could be an alternative method for biofilm reduction.