| Autor: |
Dias BDC; Laboratório de Genética Microbiana, Departamento de Microbiologia Geral, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Centro de Ciências da Saúde, Bloco I, Ilha do Fundão, Rio de Janeiro, RJ, CEP 21941.902, Brazil., Lima MEDNV; Instituto de Química, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, 21941-909, Brazil., Vollú RE; Laboratório de Genética Microbiana, Departamento de Microbiologia Geral, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Centro de Ciências da Saúde, Bloco I, Ilha do Fundão, Rio de Janeiro, RJ, CEP 21941.902, Brazil., da Mota FF; Instituto Oswaldo Cruz, Fiocruz, Rio de Janeiro, RJ, 21040-900, Brazil., da Silva AJR; Instituto de Pesquisas de Produtos Naturais, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, 21941-902, Brazil., de Castro AM; PETROBRAS R&D Center/Biotechnology, Rio de Janeiro, RJ, 21941-915, Brazil., Freire DMG; Instituto de Química, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, 21941-909, Brazil., Seldin L; Laboratório de Genética Microbiana, Departamento de Microbiologia Geral, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Centro de Ciências da Saúde, Bloco I, Ilha do Fundão, Rio de Janeiro, RJ, CEP 21941.902, Brazil. lseldin@micro.ufrj.br. |
| Abstrakt: |
2,3-Butanediol (2,3-BDO) is of considerable importance in the chemical, plastic, pharmaceutical, cosmetic, and food industries. The main bacterial species producing this compound are considered pathogenic, hindering large-scale productivity. The species Paenibacillus brasilensis is generally recognized as safe (GRAS) and is phylogenetically similar to P. polymyxa, a species widely used for 2,3-BDO production. Here, we demonstrate, for the first time, that P. brasilensis strains produce 2,3-BDO. Total 2,3-BDO concentrations for 15 P. brasilensis strains varied from 5.5 to 7.6 g/l after 8 h incubation at 32 °C in modified YEPD medium containing 20 g/l glucose. Strain PB24 produced 8.2 g/l of 2,3-BDO within a 12-h growth period, representing a yield of 0.43 g/g and a productivity of 0.68 g/l/h. An increase in 2,3-BDO production by strain PB24 was observed using higher concentrations of glucose, reaching 27 g/l of total 2,3-BDO in YEPD containing about 80 g/l glucose within a 72-h growth period. We sequenced the genome of P. brasilensis PB24 and uncovered at least six genes related to the 2,3-BDO pathway at four distinct loci. We also compared gene sequences related to the 2,3-BDO pathway in P. brasilensis PB24 with those of other spore-forming bacteria, and found strong similarity to P. polymyxa, P. terrae, and P. peoriae 2,3-BDO-related genes. Regulatory regions upstream of these genes indicated that they are probably co-regulated. Finally, we propose a production pathway from glucose to 2,3-BDO in P. brasilensis PB24. Although the gene encoding S-2,3-butanediol dehydrogenase (butA) was found in the genome of P. brasilensis PB24, only R,R-2,3- and meso-2,3-butanediol were detected by gas chromatography under the growth conditions tested here. Our findings can serve as a basis for further improvements to the metabolic capabilities of this little-studied Paenibacillus species in relation to production of the high-value chemical 2,3-butanediol. |
