paper review 전상귀

Objective : demonstrated the use of lauryl alcohol as a potential lipidic feed stock for sophorolipid production using C. bombicola.

Introduction Biosurfactants, alternatives to chemically synthesized surfactants, have garnered increasing attention. biodegradability, low toxicity and resistance to temperature and pH variations

Sophorolipids exhibit surface-active and emulsification properties, antimicrobial activities.

Sophorolipid show anticancer activity, and are recommended for the treatment of skin diseases.

Material and method

Chemicals - Lauryl alcohol (C12–-14) Stain – Candida bombicola ATCC 22214Effect of Glucose Concentration, TemperatureSeparation - centrifugation at 5000 rpm, 20min, Etyhl acetateStructural Characterization - Fourier transform infrared Surface tension Emulsification Activity Wetting Property Antibacterial Study

Result

Effect of Time

Incubation period in the range of 24–144 h at 30 C at 180 rpm.

Increase in sophorolipid yield was observed with varying time intervals

, Maximum production was obtained at 96 h.

Result

Effect of Carbon Source

Range of 5–12 %

Maximum production of SL was obtained when 10 % glucose concentration

Result

Effect of initial pH

Maximum production of SL was obtained when the initial pH of the medium was 6.0.

Result

Effect of Temperature

Range 25–35

30 C resulting in good yield of the product

Metal ions is hamper the stationary phase of the organism

Results

Effect of Metal ions

Range of 10–30 mM.

Maximum ceoncentration 20 mM of Fe2+ and Zn2+ Ions

Results

Structural Characterization of the Produced SLLA by FTIR

From the following FTIR data it could be concluded that alkylsophorosides/ sophorolipid must have formed and hence showing good surface activities.

Results

Emulsification Activity

SLLA showed good emulsifying activity

Emulsification activity was stable for the above-mentioned emulsions for more than 2 weeks.

As per the formula mentioned, the emulsification index was calculated for different surfactants

Results

Surface Tension

Surface tension of the crude sophorolipid was investigated in comparison with that of SDS, laureth 4 and SLOA.

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SLLA reduced the surface tension of distilled water to 24 mN/m with a CMC value of 0.68 mg/L.

Results

Wetting Property

Concentration increases, the wetting time decreases wetting power of the surfactants increases with increasing concentration.

Results

Contact Angle

Waterproofing or water repellency is an important industrial process, which depends on contact angle values.

A high contact angle indicates a low solid surface energy or chemical affinity

Results

Antibacterial Activity

Sophorolipids have a good inhibition property against gram positive bacteria but so far a very few reports show a satisfactory inhibition against gram negative bacteria.

It was observed that E. coli showed zero percent cell survival when sophorolipid concentration was 3 mg with an incubation time of 2 h.

Results

Antibacterial Activity

In the case of S. aureus, a sophorolipid concentration of 0.6 mg and incubation time of 4 h resulted in zero percent cell survival

SLLA showed better antibacterial ability than lauryl alcohol.

Conclusions

Modification of the lipophilic portion of the sophorolipid structure has shown to alter the physicochemical properties.

These sophorolipids were found to have higher hydrophobicity and good emulsification activity.

Surface tension reduction ability was very high compared to synthetic surfactants along with low CMC values.

Sophorolipids using lauryl alcohol have potent antimicrobial activity on both gram negative bacteria, E. coli and gram positive bacteria, S. aureus.