Lipopeptide biosurfactant from Bacillus clausii BS02 using sunflower oil soapstock: evaluation of high throughput screening methods, production, purification, characterization and its insecticidal activity

Abstract

A total of 76 bacterial isolates were screened for biosurfactant activity using 16 different high throughput screening methods. Based on phenotypic characteristics, 16S rDNA sequencing and FAME profiling, isolate BS02, identified as Bacillus clausii BS02 produced a biosurfactant (2.6 g l -1 ) when grown in basal salts mineral medium with sunflower oil soapstock (3% w/v) at 30 o C and 120 rpm after 42 h. The cell free broth showed 82% emulsification activity, critical micelle concentration of 45 mg l -1 and reduced the surface tension from 69.07 mN m -1 to 30 mN m -1 . Acid precipitated and methanol extracted crude biosurfactant had 64.3%, 28%, and 4.5% (w/w) of protein, lipid, and carbohydrate, respectively. Crude biosurfactant exhibited stability with oils, fats and non-aqueous phase liquids. Fourier transform infrared (FT-IR) spectroscopy, energy dispersive X-ray spectroscopy (EDX), and nuclear magnetic resonance spectroscopy (NMR) revealed the functional groups and bonds; X-ray diffraction (XRD) and thermogravimetry (TG) showed surface nature and thermostability of the biosurfactant, respectively. LC-ESI-MS identified the crude biosurfactant as a surfactin lipopeptide. A dose-dependent mortality against C. chinensis and M. hirsutus was observed using the crude biosurfactant, with a LC 50 of 50 µg ml -1 , indicating first evidence of insecticidal activity against pulse beetle and mealybug.

Isolation and characterization of biosurfactant-producing and diesel oil degradingPseudomonassp. CQ2 from Changqing oil field, China

“…55,56 The vegetable oils, such as sunower, peanut, corn, coconut, palm, soybean and olive oil, have been extensively utilized for biosurfactant production. [57][58][59] Reports indicated that the yield of biosurfactant was greatly affected by fermentation substrates. 60 Not only the substrates, but also the fermentation conditions will improve the production.…”

Insecticidal Activity of Bacteria from Larvae Breeding Site with Natural Larvae Mortality: Screening of Separated Supernatant and Pellet Fractions

“…For the first time in 2015, cyclic lipopeptides produced by B. clausii DTM1, exhibited herbicidal activity in addition to insecticidal activity against aphid species Plutella xylostella and Diabrotica balteata [34]. Further, the strain BS02 was active against pulse beetle and mealybug [35]. We isolated a strain of B. clausii from the larvae breeding site and, when tested on the mosquito larvae, its supernatant fraction exhibited a high insecticidal activity with 75% of larva mortality.…”

Biosurfactant from Lysinibacillus chungkukjangi from Rice Bran Oil Sludge and Potential Applications

“…4). In view of the results, it is anticipated that the biosurfactant obtained could be used for solubilizing high fat and oil prevalent in dairy industry wastewater and in cosmetic industries [22,23].…”