A biosurfactant-producing yeast Rhodotorula sp.CC01 utilizing landfill leachate as nitrogen source and its broad degradation spectra of petroleum hydrocarbons.

Biosurfactants (BSs) are known for their remarkable properties, however, their commercial applications are hampered partly by the high production cost. To overcome this issue, a biosurfactant producing strain, Rhodotorula sp.CC01 was isolated using landfill leachate as nitrogen source, while olive oil was determined as the best sole carbon source. The BS produced by Rhodotorula sp.CC01 had oil displacement diameter of 19.90 ± 0.10 cm and could reduce the surface tension of water to 34.77 ± 0.63 mN/m. It was characterized as glycolipids by thin layer chromatography, FTIR spectra, and GC-MS analysis, with the critical micelle concentration of 70 mg/L. Meanwhile, the BS showed stability over a wide range of pH (2-12), salinity (0-100 g/L), and temperature (20-100 °C). During the cultivation process, BS was produced with a maximum rate of 163.33 mg L-1 h-1 and a maximum yield of 1360 mg/L at 50 h. In addition, the removal efficiency of NH4+-N reached 84.2% after 75 h cultivation with a maximum NH4+-N removal rate of 3.92 mg L-1 h-1. Moreover, Rhodotorula sp.CC01 has proven to be of great potential in remediating petroleum hydrocarbons, as revealed by chromogenic assays. Furthermore, genes related to nitrogen metabolism and glycolipid metabolism were found in this strain CC01 after annotating the genome data with KEGG database, such as narB, glycoprotein glucosyltransferase, acetyl-CoA C-acetyltransferase, LRA1, LRA3, and LRA4. The findings of this study prove a cost-effective strategy for the production of BS by yeast through the utilization of landfill leachate.

Lin X ，Zhou H ，Zeng F ，Jiang L ，Atakpa EO ，Chen G ，Zhang C ，Xie Q ... -  《-》

Biosurfactant production from newly isolated Rhodotorula sp.YBR and its great potential in enhanced removal of hydrocarbons from contaminated soils.

Derguine-Mecheri L ，Kebbouche-Gana S ，Djenane D 《-》

Biosurfactant-producing strains in enhancing solubilization and biodegradation of petroleum hydrocarbons in groundwater.

Liu H ，Wang H ，Chen X ，Liu N ，Bao S ... -  《-》

Production, characterization, and antifungal activity of a biosurfactant produced by Rhodotorula babjevae YS3.

Sen S ，Borah SN ，Bora A ，Deka S ... -  《Microbial Cell Factories》

Investigation of halotolerant marine Staphylococcus sp. CO100, as a promising hydrocarbon-degrading and biosurfactant-producing bacterium, under saline conditions.

A halotolerant strain CO100 of Staphylococcus sp. was isolated from contaminated sediments taken from the fishing harbour of Sfax, Tunisia, as an efficient hydrocarbonoclastic candidate. Strain CO100 exhibited a high capacity to break down almost 72% of the aliphatic hydrocarbons contained in crude oil (1%, v/v), used as the sole carbon and energy source, after 20 days of culture, at 100 g/l NaCl, 37 °C and 180 rpm. The isolate CO100 displayed also its ability to grow on phenanthrene, fluoranthene and pyrene (100 mg/l), at 100 g/l NaCl. Moreover, the isolate CO100 showed a notable aptitude to synthesize an efficient tensioactive agent namely BS-CO100, on low-value substrates including residual frying oil and expired milk powder, thus reducing the high cost of biosurfactant production. The ESI/MS analysis designated that BS-CO100 belonged to lipopeptide class, in particular lichenysin and iturine members. Critical micelle concentrations of BS-CO100 were varying between 65 and 750 mg/l, depending on of the purity of the biosurfactant and the used carbon sources. BS-CO100 showed a high steadiness against a wide spectrum of pH (4.3-12), temperature (4-121 °C) and salinity (0-300 g/l NaCl), supporting its powerful tensioactive properties under various environmental conditions. Likewise, BS-CO100 exhibited no cytotoxic effect toward human HEK293 cells, at concentrations within 125 and 1000 μg/ml. Furthermore, the biosurfactant BS-CO100 exhibited remarkable anti-adhesive and anti-biofilm activities, being able to avoid and disrupt the biofilm formation by certain pathogenic microorganisms. In addition, BS-CO100 was found to have more potential to remove hydrocarbons from contaminated soils, compared to some chemical surfactants. In light of these promising findings, strain CO100, as well as its biosurfactant, could be successfully used in different biotechnological applications including the bioremediation of oil-polluted areas, even under saline conditions.

Hentati D ，Cheffi M ，Hadrich F ，Makhloufi N ，Rabanal F ，Manresa A ，Sayadi S ，Chamkha M ... -  《-》