Production of biosurfactant by salt-resistant Bacillus in lead-supplemented media: application and toxicity / Producción de biosurfactante por Bacillus resistente a la sal en medios suplementados con plomo: aplicación y toxicidad

A group of biosurfactants are lipopeptides that are produced by some microorganisms, especially Bacillus strains. They are new bioactive agents with anticancer, antibacterial, antifungal, and antiviral activities. Also, they are used in sanitation industries. In this study, a lead-resistant strain of Bacillus halotolerans was isolated for lipopeptide production. This isolate exhibited metal resistance (lead, calcium, chromium, nickel, copper, manganese, and mercury), salt tolerance (12%), and antimicrobial activities against Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and Saccharomyces cerevisiae. The production of lipopeptide was optimized, concentrated, and then extracted from the polyacrylamide gel in a simple way for the first time. The nature of the purified lipopeptide was determined by FTIR, GC/MS, and HPLC analyses. The purified lipopeptide indicated significant antioxidant properties (90.38% at a concentration of 0.8 mg ml−1). Also, it had anticancer activity by apoptosis (flow cytometry analysis) in MCF-7 cells, while it had no cytotoxicity on HEK-293 normal cells. Therefore, Bacillus halotolerans lipopeptide has the potential to be used as an antioxidant, antimicrobial, or anticancer agent in the medical and food industries.(AU)

Production of biosurfactant by salt-resistant Bacillus in lead-supplemented media: application and toxicity.

A group of biosurfactants are lipopeptides that are produced by some microorganisms, especially Bacillus strains. They are new bioactive agents with anticancer, antibacterial, antifungal, and antiviral activities. Also, they are used in sanitation industries. In this study, a lead-resistant strain of Bacillus halotolerans was isolated for lipopeptide production. This isolate exhibited metal resistance (lead, calcium, chromium, nickel, copper, manganese, and mercury), salt tolerance (12%), and antimicrobial activities against Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and Saccharomyces cerevisiae. The production of lipopeptide was optimized, concentrated, and then extracted from the polyacrylamide gel in a simple way for the first time. The nature of the purified lipopeptide was determined by FTIR, GC/MS, and HPLC analyses. The purified lipopeptide indicated significant antioxidant properties (90.38% at a concentration of 0.8 mg ml-1). Also, it had anticancer activity by apoptosis (flow cytometry analysis) in MCF-7 cells, while it had no cytotoxicity on HEK-293 normal cells. Therefore, Bacillus halotolerans lipopeptide has the potential to be used as an antioxidant, antimicrobial, or anticancer agent in the medical and food industries.

In vitro identification of antimicrobial hemolytic lipopeptide from halotolerant Bacillus by Zymogram, FTIR, and GC mass analysis.

OBJECTIVES: The multi-drug resistant bacteria and clinical infections are some of the biggest global concerns, so new drugs are needed. Antimicrobial peptides and lipopeptides are new bioactive agents with great potential that can become a new strategy for clinical applications. MATERIALS AND METHODS: Some Bacillus strains were isolated based on hemolytic antimicrobial production from the soil. The extracellular proteins were extracted by acidic precipitation and chloroform/methanol method and analyzed by SDS-PAGE electrophoresis and stained with Sudan black. The black fragment was purified and characterized by FTIR, GC/MS, and HPLC analysis to demonstrate the presence of lipids and proteins. The anti-microbial ability and stability of the purified lipopeptide were assayed by the Kirby-Bauer method. Also, it was examined for metal removal. RESULTS: A new Bacillus halotolerans strain SCM 034 with hemolytic antimicrobial production was isolated. According to GC/MS (detecting C16, C17) and HPLC (detecting leucine, glutamic acid, valine, arginine, glycine, and aspartic acid) data, the black fragment was lipopeptide. Polyacrylamide hydrogel containing lipopeptide and gel purified lipopeptide showed anti-microbial activities against S. aureus and S. cerevisiae that were stable for a few months. Also, the lipopeptide was useful for cation removal and decreased cobalt, nickel, and calcium by 10.81 %, 24.39 %, and 34 %, respectively. CONCLUSION: Production of antibacterial lipopeptide hemolysin from this strain is reported for the first time and according to the results, lipopeptides have unique properties with biomedical and pharmaceutical applications. Also, polyacrylamide hydrogel lipopeptide is a promising candidate for wound healing.

Generation of non-toxic, chemical functional bio-polymer for desalination, metal removal and antibacterial activities from animal meat by-product.

The meat industry produces a lot of waste, which contains large amounts of the organics and nutrients. Animal by-products have potential for biomaterial extraction. The use of bio-material, which can be obtained from plant sources, microorganisms, agricultural, and animal waste are nowadays favored because of their compatible, cost-effective, and low-risk for removal of pollutants, compared to chemical and physical methods. In this study, a biopolymer from meat by-product extracted by methanol-chloroform and characterized by FTIR, GC-MS, HPLC, and SDS-PAGE analyzes. The extracted biomaterial was useful in water desalination by calcium carbonate precipitation and heavy metals removal, which was confirmed by FTIR and ICP analyzes. The extracted biomaterial also has antibacterial properties against Pseudomonas aeruginosa and Escherichia coli without toxicity to human blood cells, which can make it useful in industries such as its application in fish ponds.

Heterotrophic Bioleaching of Sulfur, Iron, and Silicon Impurities from Coal by Fusarium oxysporum FE and Exophiala spinifera FM with Growing and Resting Cells.

Coal is the most abundant fossil fuel containing sulfur and other elements which promote environmental pollution after burning. Also the silicon impurities make the transportation of coal expensive. In this research, two isolated fungi from oil contaminated soil with accessory number KF554100 (Fusarium oxysporum FE) and KC925672 (Exophiala spinifera FM) were used for heterotrophic biological leaching of coal. The leaching were detected by FTIR, CHNS, XRF analyzer and compared with iron and sulfate released in the supernatant. The results showed that E. spinifera FM produced more acidic metabolites in growing cells, promoting the iron and sulfate ions removal while resting cells of F. oxysporum FE enhanced the removal of aromatic sulfur. XRF analysis showed that the resting cells of E. spinifera FM proceeded maximum leaching for iron and silicon (48.8, 43.2 %, respectively). CHNS analysis demonstrated that 34.21 % of sulfur leaching was due to the activities of resting cells of F. oxysporum FE. Also F. oxysporum FE removed organic sulfur more than E. spinifera FM in both growing and resting cells. FTIR data showed that both fungi had the ability to remove pyrite and quartz from coal. These data indicated that inoculations of these fungi to the coal are cheap and impurity removals were faster than autotrophic bacteria. Also due to the removal of dibenzothiophene, pyrite, and quartz, we speculated that they are excellent candidates for bioleaching of coal, oil, and gas.