Morales-Borrell Dayana, González-Fernández Nemecio, Mora-González Néstor, Pérez-Heredia Carlos, Campal-Espinosa Ana, Bover-Fuentes Eddy, Salazar-Gómez Eladio, Morales-Espinosa Yissel
Department of Research and Development, Center for Genetic Engineering and Biotechnology (CIGB) of Camagüey, PO Box address: 387, 70100, Camagüey, Cuba.
Faculty of Forest Sciences, University of Concepcion, Concepción, Chile.
AMB Express. 2020 Oct 23;10(1):190. doi: 10.1186/s13568-020-01127-y.
Culture medium composition is one of the most important parameters to analyze in biotechnological processes with industrial purposes. The aim of this study was to design of a culture medium for optimal growth of the bacterium Pseudoxanthomonas indica H32 allowing its production as biopesticide and biofertilizer. The influence of several carbon and nitrogen sources and their molar ratios on P. indica H32 growth was investigated. The effect of different micronutrients such as mineral salts and vitamin on P. indica H32 growth was determined as well. A mixture design based on Design-Expert 10.0 Software was performed to optimize the culture medium concentration. Finally, in the designed medium, an attribute of the biological mechanism of action of the P. indica H32 against nematodes, was evaluated: the hydrogen sulfide production. It was found that tested carbon/nitrogen ratios were not a significant influence on P. indica H32 growth. Growth of P. indica H32 was favored with use of sucrose, yeast extract and phosphate buffer without the addition of any tested micronutrients. An optimal concentration of 10 g/L sucrose and 5 g/L yeast extract were obtained at a cost of 0.10 $/L. In this concentration, the specific growth rate (µ) and maximal optical density (Xmax) were equal to 0.439 h and 8.00 respectively. It was evidenced that under the culture conditions used, P. indica H32 produced hydrogen sulfide. The designed medium led to a 1.08 $/L reduction of costs in comparison to LB medium. These results were critical to carry on with biotechnological development of P. indica H32 as a bioproduct.
培养基组成是工业用途生物技术过程中要分析的最重要参数之一。本研究的目的是设计一种培养基，以实现印度假黄单胞菌H32的最佳生长，使其能够作为生物农药和生物肥料生产。研究了几种碳源和氮源及其摩尔比对印度假黄单胞菌H32生长的影响。还测定了不同微量营养素（如矿物盐和维生素）对印度假黄单胞菌H32生长的影响。基于Design-Expert 10.0软件进行了混合设计，以优化培养基浓度。最后，在设计的培养基中，评估了印度假黄单胞菌H32对线虫的生物作用机制的一个属性：硫化氢的产生。结果发现，测试的碳/氮比对印度假黄单胞菌H32的生长没有显著影响。在不添加任何测试微量营养素的情况下，使用蔗糖、酵母提取物和磷酸盐缓冲液有利于印度假黄单胞菌H32的生长。以0.10美元/升的成本获得了10克/升蔗糖和5克/升酵母提取物的最佳浓度。在此浓度下，比生长速率（µ）和最大光密度（Xmax）分别等于0.439小时和8.00。结果表明，在所使用的培养条件下，印度假黄单胞菌H32产生了硫化氢。与LB培养基相比，设计的培养基使成本降低了1.08美元/升。这些结果对于推进印度假黄单胞菌H32作为生物产品的生物技术开发至关重要。
