Premium
Ultrafiltration based purification strategies for surfactin produced by Bacillus subtilis LB5A using cassava wastewater as substrate
Author(s) -
de Andrade Cristiano J,
Barros Francisco FC,
de Andrade Lidiane M,
Rocco Silvana A,
Luis Sforça Mauricio,
Pastore Gláucia M,
Jauregi Paula
Publication year - 2016
Publication title -
journal of chemical technology and biotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.64
H-Index - 117
eISSN - 1097-4660
pISSN - 0268-2575
DOI - 10.1002/jctb.4928
Subject(s) - surfactin , downstream processing , ultrafiltration (renal) , chromatography , chemistry , bacillus subtilis , membrane , wastewater , bioproduction , lipopeptide , membrane fouling , fouling , bacteria , biochemistry , waste management , biology , genetics , engineering
BACKGROUND Bacillus subtilis synthesizes surfactin, a powerful surface‐active agent. It has interesting potential applications. However, due to its high cost of production, commercial use is impracticable. The downstream processing represents ≈ 60% of production costs and the culture medium ≈ 30%. Many reports focused, separately, on production of surfactin using by‐products (reduced cost) or the purification using synthetic medium. Therefore, the aim of this work was to evaluate, for the first time, the impact of using a by‐product as fermentation medium on the downstream processing based on membrane filtration. RESULTS Membranes of PES ‐100‐ kDa efficiently retained surfactin micelles – the first step of ultrafiltration, whereas, the second step required membranes of 50 kDa to separate surfactin monomers from proteins. Ultrafiltration of crude biosurfactant was associated with fouling and/or concentration polarization resulting in lower purity than when synthetic medium was used. Further improvement in purity was achieved by partial removal of proteins before ultrafiltration by acid precipitation and extraction. The NMR and MALDI‐TOFMS analyses identified 11 potential surfactin homologues composed of two amino acid sequences. CONCLUSION Production of surfactin using cassava wastewater as a low‐cost culture medium and its purification by the 2‐step ultrafiltration process is feasible, nevertheless, the higher protein content of this medium compared with the synthetic one leads to a lower purity product; further increase in purity can be achieved by applying additional purification steps prior to ultrafiltration with subsequent increased process cost. © 2016 Society of Chemical Industry