Ontañon Ornella M, Bedő Soma, Ghio Silvina, Garrido Mercedes M, Topalian Juliana, Jahola Dóra, Fehér Anikó, Valacco Maria Pia, Campos Eleonora, Fehér Csaba
Instituto de Agrobiotecnología y Biología Molecular (IABIMO), Instituto Nacional de Tecnología Agropecuaria (INTA), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), De los Reseros y N. Repetto s/n, Hurlingham, B1686IGC, Buenos Aires, Argentina.
Biorefinery Research Group, Department of Applied Biotechnology and Food Science, Budapest University of Technology and Economics (BUTE), Szent Gellért tér 4, Budapest, H-1111, Hungary.
Appl Microbiol Biotechnol. 2021 Jun;105(11):4577-4588. doi: 10.1007/s00253-021-11305-y. Epub 2021 May 21.
One of the main distinguishing features of bacteria belonging to the Cellulomonas genus is their ability to secrete multiple polysaccharide degrading enzymes. However, their application in biomass deconstruction still constitutes a challenge. We addressed the optimisation of the xylanolytic activities in extracellular enzymatic extracts of Cellulomonas sp. B6 and Cellulomonas fimi B-402 for their subsequent application in lignocellulosic biomass hydrolysis by culture in several substrates. As demonstrated by secretomic profiling, wheat bran and waste paper resulted to be suitable inducers for the secretion of xylanases of Cellulomonas sp. B6 and C. fimi B-402, respectively. Both strains showed high xylanolytic activity in culture supernatant although Cellulomonas sp. B6 was the most efficient xylanolytic strain. Upscaling from flasks to fermentation in a bench scale bioreactor resulted in equivalent production of extracellular xylanolytic enzymatic extracts and freeze drying was a successful method for concentration and conservation of the extracellular enzymes, retaining 80% activity. Moreover, enzymatic cocktails composed of combined extra and intracellular extracts effectively hydrolysed the hemicellulose fraction of extruded barley straw into xylose and xylooligosaccharides. KEY POINTS: • Secreted xylanase activity of Cellulomonas sp. B6 and C. fimi was maximised. • Biomass-induced extracellular enzymes were identified by proteomic profiling. • Combinations of extra and intracellular extracts were used for barley straw hydrolysis.
属于纤维单胞菌属的细菌的主要区别特征之一是它们分泌多种多糖降解酶的能力。然而，它们在生物质解构中的应用仍然是一项挑战。我们针对纤维单胞菌B6和纤维单胞菌B - 402的细胞外酶提取物中的木聚糖分解活性进行了优化，以便通过在几种底物中培养将其随后应用于木质纤维素生物质水解。正如分泌蛋白质组分析所表明的，麦麸和废纸分别是纤维单胞菌B6和纤维单胞菌B - 402分泌木聚糖酶的合适诱导物。尽管纤维单胞菌B6是最有效的木聚糖分解菌株，但两种菌株在培养上清液中均显示出高木聚糖分解活性。从摇瓶放大到台式规模生物反应器中的发酵，细胞外木聚糖分解酶提取物的产量相当，冷冻干燥是浓缩和保存细胞外酶的成功方法，可保留80%的活性。此外，由细胞外和细胞内提取物组合而成的酶混合物有效地将挤压大麦秸秆的半纤维素部分水解为木糖和低聚木糖。要点：• 纤维单胞菌B6和纤维单胞菌的分泌木聚糖酶活性最大化。• 通过蛋白质组分析鉴定生物质诱导的细胞外酶。• 使用细胞外和细胞内提取物的组合进行大麦秸秆水解。
