Biological control of bacterial contamination and its application on industrial biotechnological process

Abstract

Bacterial contamination by Lactobacillus sp. is one of the main causes of sugar losses and cost increase in ethanol fermentation. The losses in ethanol fermentation may reach 27% due to bacterial contamination, which also raises the cost of production by the use of antibiotics. Contamination levels can reach a level of 10^7 causing negative impacts on fermentation, such as pH modification due to the production of lactic acid and competition for sugars. The objective of this work is the development a biological control process to minimize the problem of bacterial contamination in alcoholic fermentation tanks and/or other industrial processes using bacteriophages and/or endolysins produced as result of phage infection. Among the advantages of the use of bacteriophages are the lower cost of production due the use of antibiotics and the effectiveness and specificity against the contaminating bacteria of the process. Lytic bacteriophages will be prospected and isolated from ethanol fermentation tanks and tested on its specificity to contaminating bacteria. The isolated phages will be categorized in terms of the their capacity of bacterial infection as well the endolysins produced allowing the creation of bacteriophage cocktails optimized for the contaminant populations of industrial ethanol production processes. The identification of new endolysins and bacteriophages with a broad spectrum of action will permit the substitution of the industrial use of antibiotics, constituting a new and wide market. (AU)