在简单培养基中过表达estA的铜绿假单胞菌提高鼠李糖脂产量。

Enhanced rhamnolipid production by Pseudomonas aeruginosa overexpressing estA in a simple medium.

作者信息

Dobler Leticia, de Carvalho Bruna Rocha, Alves Wilber de Sousa, Neves Bianca Cruz, Freire Denise Maria Guimarães, Almeida Rodrigo Volcan

机构信息

LaMMP-Laboratório de Microbiologia Molecular e de Proteínas, Chemistry Institute, Federal University from Rio de Janeiro, Rio de Janeiro, Brazil.

LaBiM-Laboratório de Biotecnologia Microbiana, Chemistry Institute, Federal University from Rio de Janeiro, Rio de Janeiro, Brazil.

出版信息

PLoS One. 2017 Aug 24;12(8):e0183857. doi: 10.1371/journal.pone.0183857. eCollection 2017.

A modified Pseudomonas aeruginosa strain capable of overexpressing the estA gene, an encoding gene for a membrane-bound esterase, was constructed and its rhamnolipid (RML) production was studied. Fermentations using wild-type (WT) and modified P. aeruginosa strains were conducted until exhaustion of glycerol in Medium Salt Production, using two different C/N ratios. At a C/N of 83.2, the modified strain produced up to 3.9 times more RMLs than the WT, yielding a maximum concentration of 14.62 g/L RML when measured by HPLC and 22 g/L by the orcinol assay. Cell-free supernatant from the modified strain reduced surface tension to 29.4 mN/m and had a CMC of 240 mg/L and CMD of 56.05. This is the first report on the construction of an estA-based recombinant strain for RML production.

构建了一种能够过表达estA基因（一种膜结合酯酶的编码基因）的修饰铜绿假单胞菌菌株，并对其鼠李糖脂（RML）的产生进行了研究。使用野生型（WT）和修饰的铜绿假单胞菌菌株在中盐生产培养基中进行发酵，直至甘油耗尽，采用两种不同的碳氮比。在碳氮比为83.2时，修饰菌株产生的RML比野生型多3.9倍，通过高效液相色谱法测定时，RML的最大浓度为14.62 g/L，通过苔黑酚法测定为22 g/L。修饰菌株的无细胞上清液将表面张力降低至29.4 mN/m，临界胶束浓度为240 mg/L，临界溶解浓度为56.05。这是关于构建用于生产RML的基于estA的重组菌株的首次报道。