Nunes Luiza Varela, de Barros Correa Fabiane Fernanda, de Oliva Neto Pedro, Mayer Cassia Roberta Malacrida, Escaramboni Bruna, Campioni Tania Sila, de Barros Natan Roberto, Herculano Rondinelli Donizetti, Fernández Núñez Eutimio Gustavo
Grupo de Engenharia de Bioprocessos, Departamento de Ciências Biológicas, Universidade Estadual Paulista 'Júlio de Mesquita Filho' Campus-Assis, Avenida Dom Antônio, 2100, Assis, SP, 19806-900, Brazil.
Laboratório de Biotecnologia Industrial, Departamento de Biotecnologia, Universidade Estadual Paulista 'Júlio de Mesquita Filho' Campus-Assis, Avenida Dom Antônio, 2100, Assis, SP, 19806-900, Brazil.
World J Microbiol Biotechnol. 2017 Apr;33(4):79. doi: 10.1007/s11274-017-2240-7. Epub 2017 Mar 24.
The present work aimed to characterize and optimize the submerged fermentation of broken rice for lactic acid (LA) production using undefined mixed culture from dewatered activated sludge. A microorganism with amylolytic activity, which also produces LA, Lactobacillus amylovorus, was used as a control to assess the extent of mixed culture on LA yield. Three level full factorial designs were performed to optimize and define the influence of fermentation temperature (20-50 °C), gelatinization time (30-60 min) and broken rice concentration in culture medium (40-80 g L) on LA production in pure and undefined mixed culture. LA production in mixed culture (9.76 g L) increased in sixfold respect to pure culture in optimal assessed experimental conditions. The optimal conditions for maximizing LA yield in mixed culture bioprocess were 31 °C temperature, 45 min gelatinization time and 79 g L broken rice concentration in culture medium. This study demonstrated the positive effect of undefined mixed culture from dewatered activated sludge to produce LA from culture medium formulated with broken rice. In addition, this work establishes the basis for an efficient and low-cost bioprocess to manufacture LA from this booming agro-industrial by-product.
本研究旨在利用脱水活性污泥中的未定义混合培养物，对碎米进行乳酸（LA）生产的深层发酵进行表征和优化。以具有淀粉分解活性且能产生LA的解淀粉乳杆菌作为对照，评估混合培养对LA产量的影响程度。进行了三水平全因子设计，以优化和确定发酵温度（20 - 50°C）、糊化时间（30 - 60分钟）和培养基中碎米浓度（40 - 80 g/L）对纯培养和未定义混合培养中LA产量的影响。在最佳评估实验条件下，混合培养中的LA产量（9.76 g/L）相对于纯培养提高了六倍。混合培养生物过程中使LA产量最大化的最佳条件为温度31°C、糊化时间45分钟和培养基中碎米浓度79 g/L。本研究证明了脱水活性污泥中的未定义混合培养物对以碎米配制的培养基生产LA具有积极作用。此外，这项工作为利用这种蓬勃发展的农业工业副产品生产LA建立高效低成本生物过程奠定了基础。
