Production and Characterization of Phospholipases C from some Bacillus thuringiensis Isolates Recovered from Egyptian Soil

Abstract

Two hundred and thirty one isolates, with the characteristic morphology of Genus Bacillus, were recovered from 100 soil samples collected from 7 different Egyptian governorates, and were screened for phospholipase C (PLC) production by egg-yolk plate method. Sixty isolates have shown very high PLC production and were further assessed using chromogenic assay method. The highest five producers, identified by 16S rRNA gene sequencing as Bacillus thuringiensis, were selected and their PLCs were purified to homogeneity using ammonium sulfate precipitation and Sephadex G-75 gel filtration chromatography. PLCs had molecular masses of 28.5 kDa as indicated by SDS-PAGE. The characteristics of the studied five PLCs were having maximal activities at 35-45°C and pH 7.2. The enzymes could retain more than half of their maximum activities at 30-60°C and pH 7-8. Equivalent activities were recorded at low water tension. PLC from B. thuringiensis KT159186 was relatively thermostable with a maximum activity at 40°C. The halfinactivation temperature was above 50°C, which compared favorably to that of other enzymes. Activity at the wide temperature range (20-80°C) was high (about 50% of maximum),. This PLC could tolerate pH as high as 12 with only 30% loss of activity. Specificity pattern of PLC from the same isolate showed equivalent activities toward phosphatidylcholine and phosphatidylinositol in addition to marked activity toward phosphatidylethanolamine, which makes it a typical non-specific PLC for industrial purposes. In conclusion, these characteristics of PLC from the test isolate make it attractive for various industrial applications.

Characterization of culturable bacteria from pulp and paper industry wastewater, with the potential for degradation of cellulose, starch, and lipids

“…The extracellular lipase of Bacillus subtilis (Ma et al 2018) was reported. Additionally, Aboulwafa et al (2016) reported that B. thuringiensis is a strong producer (Pz = 0.49 in the current study). Genes encoding degradative lipases have been studied (Dubois et al 2012;Slamti et al 2014).…”

Exploring the Genomic Landscape of Bacillus paranthracis PUMB_17 as a Proficient Phosphatidylcholine-Specific Phospholipase C Producer

“…For purification of PC-PLC from a strain of B. thuringiensis isolated from Egyptian soil, Aboulwafa et al [ 68 ] reported a salting-out step with ammonium sulfate and molecular-sieve chromatography on Sephadex G-75. Eddelech and coworkers [ 69 ] have purified PC-PLC from a Tunisian strain of B. thuringiensis using ammonium sulfate precipitation, followed by Sephadex G-75 and Q-Sepharose column chromatography.…”

Production of highly cytotoxic and low immunogenic L-asparaginase from Stenotrophomonas maltophilia EMCC2297

“…The obtained pellets were dispersed in 0.05 M Tris-HCl buffer (pH 8.6). The prepared suspension was dialyzed in a dialysis tube with molecular weight cut-off 13,000Da against 250 ml of the same buffer with stirring at 4 °C overnight (Elleboudy et al 2016 ). The dialyzed enzyme was subjected for further purification by loading into Sephadex G-100 size exclusion column (2.5* 30 cm).…”

“…Also, they were tested for L-asparaginase activity. The active fractions of L-asparaginase were pooled and used for further analysis (Elleboudy et al 2016 ).…”