Cost-effective rhamnolipid production by Burkholderia thailandensis E264 using agro-industrial residues.
Appl Microbiol Biotechnol
; 106(22): 7477-7489, 2022 Nov.
Article
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| MEDLINE
| ID: mdl-36222896
ABSTRACT
The agro-industrial by-products corn steep liquor (CSL) and olive mill wastewater (OMW) were evaluated as low-cost substrates for rhamnolipid production by Burkholderia thailandensis E264. In a culture medium containing CSL (7.5% (v/v)) as sole substrate, B. thailandensis E264 produced 175 mg rhamnolipid/L, which is about 1.3 times the amount produced in the standard medium, which contains glycerol, peptone, and meat extract. When the CSL medium was supplemented with OMW (10% (v/v)), rhamnolipid production further increased up to 253 mg/L in flasks and 269 mg/L in a bioreactor. Rhamnolipids produced in CSL + OMW medium reduced the surface tension up to 27.1 mN/m, with a critical micelle concentration of 51 mg/L, better than the values obtained with the standard medium (28.9 mN/m and 58 mg/L, respectively). However, rhamnolipids produced in CSL + OMW medium displayed a weak emulsifying activity when compared to those produced in the other media. Whereas di-rhamnolipid congeners represented between 90 and 95% of rhamnolipids produced by B. thailandensis E264 in CSL and the standard medium, the relative abundance of mono-rhamnolipids increased up to 55% in the culture medium containing OMW. The difference in the rhamnolipid congeners produced in each medium explains their different surface-active properties. To the best of our knowledge, this is the first report of rhamnolipid production by B. thailandensis using a culture medium containing agro-industrial by-products as sole ingredients. Furthermore, rhamnolipids produced in the different media recovered around 60% of crude oil from contaminated sand, demonstrating its potential application in the petroleum industry and bioremediation. KEY POINTS ⢠B. thailandensis produced RL using agro-industrial by-products as sole substrates ⢠Purified RL displayed excellent surface activity (minimum surface tension 27mN/m) ⢠Crude RL (cell-free supernatant) recovered 60% of crude oil from contaminated sand.
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Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Petróleo
/
Burkholderia
Tipo de estudio:
Health_economic_evaluation
Idioma:
En
Revista:
Appl Microbiol Biotechnol
Año:
2022
Tipo del documento:
Article
País de afiliación:
Portugal