Cholesterol is a waxy substance present in all types of the body cells. The presence of higher concentration of low density lipoprotein (LDL) is characterized by abnormal cholesterol level and is associated with cardiovascular diseases which lead to the development of atheroma in arteries known as atherosclerosis. The transformation of cholesterol by bacterial cholesterol oxidase can provide a key solution for the treatment of diseases related to cholesterol and its oxidized derivatives. Previously isolated bacteria from oil-contaminated soil were screened for cholesterol degradation. Among fourteen, five isolates were able to utilize cholesterol. Two strains Serratia marcescens W1 and Bacillus pumilus W8 using cholesterol as only carbon and energy source were selected for degradation studies. Several parameters (incubation time, substrate concentration, pH, temperature, and different metal ions) for cholesterol decomposition by the selected bacterial strains were evaluated. Maximum cholesterol reduction was achieved on the 5th day of incubation, 1g/L of substrate concentration, pH 7, in the presence of Mg2+ and Ca2+ ions, and at 35°C. Cholesterol degradation was analyzed by enzymatic colorimetric method, thin layer chromatography (TLC), and high-performance liquid chromatography (HPLC). Under optimized conditions 50% and 84% cholesterol reduction were recorded with Serratia marcescens W1 and Bacillus pumilus W8, respectively. Cholesterol oxidase activity was assayed qualitatively and quantitatively. The results revealed that Serratia marcescens W1 and Bacillus pumilus W8 have great potential for cholesterol degradation and would be regarded as a source for cholesterol oxidase (CHO).

At present time, every nation is absolutely concern about increasing agricultural production and bioremediation of petroleum-contaminated soil. Hence, with this intention in the current study potent natural surfactants characterized as lipopeptides were evaluated for low-cost production by Bacillus subtilis SNW3, previously isolated from the Fimkessar oil field, Chakwal Pakistan. The significant results were obtained by using substrates in combination (white beans powder (6% w/v) + waste frying oil (1.5% w/v) and (0.1% w/v) urea) with lipopeptides yield of about 1.17 g/L contributing 99% reduction in cost required for medium preparation. To the best of our knowledge, no single report is presently describing lipopeptide production by Bacillus subtilis using white beans powder as a culture medium. Additionally, produced lipopeptides display great physicochemical properties of surface tension reduction value (SFT = 28.8 mN/m), significant oil displacement activity (ODA = 4.9 cm), excessive emulsification ability (E24 = 69.8%), and attains critical micelle concentration (CMC) value at 0.58 mg/mL. Furthermore, biosurfactants produced exhibit excellent stability over an extensive range of pH (1–11), salinity (1–8%), temperature (20–121°C), and even after autoclaving. Subsequently, produced lipopeptides are proved suitable for bioremediation of crude oil (86%) and as potent plant growth-promoting agent that significantly (P < 0.05) increase seed germination and plant growth promotion of chili pepper, lettuce, tomato, and pea maximum at a concentration of (0.7 g/100 mL), showed as a potential agent for agriculture and bioremediation processes by lowering economic and environmental stress. Graphical Abstract

At present time, every nation is absolutely concern about increase agricultural production and bioremediation of petroleum contaminated soil. Hence, with this intention in current study potent natural surfactant (surfactin) was evaluated for low-cost production by Bacillus subtilis SNW3, previously isolated from Fimkessar oil field, Chakwal Pakistan. The best results were obtained using substrates in combination (white beans powder (6% w/v) plus waste frying oil (1.5% w/v) and (0.1% w/v) urea) with surfactin production of about 1.17 g/L contributing 99% reduction in cost required for medium preparation. To the best of our knowledge, no single report is present describing surfactin production by Bacillus subtilis using white beans powder as a culture medium. Surfactin was confirmed as the principal product characterized by thin-layer chromatography (TLC) and Fourier-transform infrared spectroscopy (FTIR). Additionally, produced surfactin display great physicochemical properties of surface tension reduction value (SFT=28.8 mN/m), significant oil displacement activity (ODA=4.9 cm), excessive emulsification ability (E24=69.8 %), and attains critical micelle concentration (CMC) value at 0.58 mg/mL. Furthermore, surfactin exhibits excellent stability over an extensive range of pH (1-11), salinity (1-8%), temperature (20-121°C) and even after autoclaving. Subsequently, surfactin produced proved suitable for bioremediation of crude oil (86%) and as potent plant growth-promoting agent that significantly (P<0.05) increase seed germination and plant growth promotion of chili pepper, lettuce, tomato and pea maximum at concentration of (0.7 g/100 mL), proved as potential agent for agriculture and bioremediation processes by lowering economic and environmental stress.

Background: Biosurfactants, being environment friendly, highly biodegradable, less toxic and stable compounds have applications in several environmental and industrial sectors that includes cosmetics, biomedical, bioremediation, and agriculture. Growing concern about eco-friendly compounds leads to replacement of chemical surfactants with biological surfactants. However, use of biosurfactant limits due to high production cost. Surfactin, a class of lipopeptide, considered as powerful biosurfactants having wide applications in therapeutics and environmental field. This study aims to investigate production and characterization of surfactin by Bacillus subtilis SNW3 and evaluating their potential application in seed germination and plant growth. Results: In present study, Bacillus subtilis SNW3 was previously isolated from Chakwal Pakistan and used for biosurfactant production. Optimized media for biosurfactant production was at (6% w/v) white beans powder in combination with (1.5% w/v) waste frying oil and (0.1% w/v) urea that shows surface tension reduction (28.8 mN/m), oil displacement assay (4.9 cm) and emulsification index (69.8 %). Environmental growth parameters like temperature (30 °C), inoculum size (1%), pH (6) and agitation (150 rpm) exhibit important role towards enhanced biosurfactant yield. Furthermore, surfactin obtained was found to be most stable at (5-7) pH, (8%) NaCl and (100 °C) temperature. Biosurfactant obtained was of lipopeptide nature called surfactin characterized by thin-layer chromatography (TLC) and fourier-transform infrared spectroscopy (FTIR). The surfactin obtained, used in a concentration of (0.7 g/100 mL) helps in seed germination and significantly enhanced growth of Solanum lycopersicum (tomato), Pisum sativum (pea), Capsicum annuum (peppers) and Lactuca sativa (lettuce).Conclusions: Bacillus subtilis SNW3 produces surfactin with more stability, that makes it useful for processing of food and in agriculture. The use of white beans powder and waste frying oil as sole source of carbon and energy makes the biosurfactant production more profitable, and environment friendly procedure by utilizing food processing by-products and wastes as substrate. Results obtained provide understanding about surfactin use for seed development and plant growth.