Organochlorine pesticide residues continue to remain as a major environmental threat worldwide. Lindane is an organochlorine pesticide widely used as an acaricide in medicine and agriculture. In the present study, a new lindane degrading yeast strain, Pseudozyma VITJzN01 was identified as copious producer of glycolipid biosurfactant. The glycolipid structure and type was elucidated by FTIR, NMR spectroscopy and GC-MS analysis. The surface activity and stability of glycolipid was analyzed. The glycolipids characterized as mannosylerythritol lipids (MELs) exhibited excellent surface active properties and the surface tension of water was reduced to 29 mN/m. The glycolipid was stable over a wide range of pH, temperature and salinity, showing a very low CMC of 25 mg/l. Bio-microemulsion of olive oil-in-water (O/W) was prepared using the purified biosurfactant without addition of any synthetic cosurfactants, for lindane solubilization and enhanced degradation assay in liquid and soil slurry. The O/W bio-microemulsions enhanced the solubility of lindane up to 40 folds. Degradation of lindane (700 mg/l) by VITJzN01 in liquid medium amended with bio-microemulsions was found to be enhanced by 36% in 2 days, compared to degradation in 12 days in the absence of bio-microemulsions. Lindane spiked soil slurry incubated with bio-microemulsions also showed 20-40% enhanced degradation compared to the treatment with glycolipids or yeast alone. This is the first report on lindane degradation by Pseudozyma sp., and application of bio-microemulsions for enhanced lindane degradation. MEL stabilized bio-microemulsions can serve as a potential tool for enhanced remediation of diverse lindane contaminated environments.
[Show abstract][Hide abstract] ABSTRACT: A single step photometric micromethod for determination of fatty acids in lipids in benzene solution, using rhodamine 6G reagent,
has been developed. The method eliminates the disadvantage of formation of a biphasic system and is applicable in the presence
of glycerides, sterols, epoxy compounds, hydrocarbons and long chain hydroxy compounds such as long chain fatty alcohols.
The long chain fatty acids from C12 to C22, both saturated and unsaturated, can be determined with reasonable accuracy in the concentration range of 0.08–0.25 µmole/ml.
The method is simple, rapid, and requires relatively inexpensive chemicals.
[Show abstract][Hide abstract] ABSTRACT: An efficient biosurfactant-producing bacterium was isolated and cultured from petroleum reservoir
in northeast China. Isolate was screened for biosurfactant production using haemolytic assay, Cetyl
Trimethyl Ammonium Bromide agar plate assay (CTAB) and the qualitative oil-displacement test. Based
on partial sequenced 16S rDNA analysis of isolate, USTBa, identified as Bacillus methylotrophicus with
100% identity. This bacterium was able to produce a type of biosurfactant with excessive foam-forming
properties. The maximum biosurfactant production was obtained when the cells were grown on minimal
salt medium containing 2% (v/v) crude-oil as the sole source of carbon at 35 ◦C and 180 rpm after 192 h.
This strain had a high emulsification activity and biosurfactant production of 78% and 1.8 g/L respectively.
The cell free broth containing biosurfactant could reduce the surface tension to 28 mN/m. Fourier transform
infrared (FT-IR) spectrum of extracted biosurfactant indicates the presence of carboxyl, hydroxyl
and methoxyl functional groups. Elemental analysis of the biosurfactant by Energy dispersive X-ray spectroscopy
(EDS) reveals that the biosurfactant was anionic in nature. The strain USTBa represented as a
potent biosurfactant-producer and could be useful in variety of biotechnological and industrial processes,
particularly oil industry.
[Show abstract][Hide abstract] ABSTRACT: Pseudomonas nitroreducens TSB.MJ10 exhibiting growth and bioemulsifier production with 0.5% sodium benzoate as the sole carbon source was isolated from a mangrove ecosystem in the vicinity of a petroleum pump. The bioemulsifier is a lipopeptide that is stable over a pH range of 5-11 and a temperature range of 20-90°C and showed emulsifying activity in the presence of relatively high NaCl concentrations (up to 25%). The bioemulsifier formed stable emulsions with aliphatic (hexadecane, n-heptane, cyclohexane), aromatic (xylene, benzene, toluene) and petroleum (gasoline, diesel, kerosene, crude oil) compounds. It exhibited a maximum emulsification activity with weathered crude oil (97%) and was capable of transforming the rheological behavior of the pseudoplastic to a Newtonian fluid. The results reveal the potential of the bioemulsifier for use in bioremediation of hydrocarbons in marine environments and in enhanced oil recovery.
Data provided are for informational purposes only. Although carefully collected, accuracy cannot be guaranteed. The impact factor represents a rough estimation of the journal's impact factor and does not reflect the actual current impact factor. Publisher conditions are provided by RoMEO. Differing provisions from the publisher's actual policy or licence agreement may be applicable.