Production, purification and characterization of polysaccharide lytic enzymes of a marine isolate, Bacillus cereus NRC-20 and their application in biofilm removal

Abstract

In screening for marine bacterial polysaccharide lytic enzymes, the most potent isolate was identified as Bacillus cereus NRC-20. This strain showed high alginase, dextrinase, pectinase and carboxymethylecellulase productivity when production medium was adjusted at pH 6.0 and contains (g/l): 3.0 sodium alginate, 3.0 malt extract, 30.0 jatropha cake and inoculated with 8% (v/v) of a 24 h old cell suspension and incubated at 30°C for 48 h on a rotary shaker at 200 rpm. These enzymes mixture were precipitated by 60% acetone and purified by using sephadex G-100, whereas SDS-PAGE suggested a molecular weight of approximately 17, 20, 89 and 279 KDa, respectively. The optimum partially purified enzymes activity when enzyme protein concentration was 27.4 mg/ml and substrate concentration 5.0 g/l shown after 90 min of incubation at 30°C and pH 5 and stable at 60°C for 60 min. The enzymes activities were enhanced in the presence of 0.02 M Na + and K + ions and completely inactivated by Mg +2 , Cu +2 , Co +2 and Pb +2 The enzymes mixture affected the matrix integrity of different microbial biofilms artificially grown on stainless steel sheets of Bacillus subtilis NRRL B-4219, Staphylococcus aureus ATCC 29213, Pseudomonas aeruginosa ATCC 27953 and Escherichia coli ATCC 25922.

STATISTICAL APPROACH FOR PECTINASE PRODUCTION BY Bacillus firmus SDB9 AND EVALUATION OF PECTINO-XYLANOLYTIC ENZYMES FOR PRETREATMENT OF KRAFT PULP

“…Highest pectinase activity was found 1.94 IU.mL -1 during the early stationary phase at 48 h. The Xylanase activity topped to 0.34 IU.mL -1 at 48 h of fermentation with as negligible as 0.086 IU.mL -1 cellulase activity at 54 h ( Figure 2b). Early production of pectinase was found within 48 h that is desirable for large scale production.Similar rapid pectinase production was reported in Bacillus licheniformis (Rehman et al, 2012), Bacillus cereus (Sanaa et al, 2014) and even in yeast Saccharomyces cerevisiae (Poondla et al, 2015). The use of concurrently produced pectinase and xylanase from the single organism in the pretreatment of kraft pulp can be economically as well as environmentally friendly (Kaur et al, 2010).…”