Production of natural folate and riboflavin by lactic acid bacteria isolatesd from goat's milk and cheese produced in São paulo, Brazil

PACHECO DA SILVA, F.F.; LEBLANC, J.G.; FRANCO, B. D. G. M.

San Miguel de Tucuman

Simposio; IV Simposio Internacional de Bacterias Lácticas (SIBAL) Alimentos, Salud y Aplicaciones; 2013

Goat milk is considered an important product in many countries due to its economic and nutritional values. The importanthigh nutritional propertiesvalues and organoleptic characteristics have made its dairy products, such as cheeses, recognized as high value-added products. The majority of fermented products are produced by lactic acid bacteria (LAB) which have a lot of beneficial properties. Some LAB possess the ability to produce vitamins which are micronutrients that are essential for the metabolism of living organisms.  B-group vitamins, such as folate and riboflavin (B2), play important roles in metabolic processes such as energy production and nucleotides and enzymes synthesis. The aim of this study was to determinate the production of natural folate and riboflavin by LAB isolatesd from goat´s milk and cheeses produced in São Paulo, Brazil. A total of 127 strainsLAB were isolated from goat´s milk and cheeses samples and identified as being Gram + and catalase negative. Thirty-four, 34 (10 isolates from cheeses and 24 isolates from goat´s milk) of which were able to grow in the absence of folate after 7 passages in folate-free medium. These 34 isolates were used to determinate the extracellular (EC) and intracellular (IC) production of natural folate and riboflavin. Folate determination was performed using a modified microbiological assay using Lactobacillus casei subsp. rhamnosus NCIMB 10463 as indicator strain. Riboflavin determination was performed using a similar microbiological assay using Lactobacillus rhamnosus ATCC 7469 as indicator strain. The average of total  natural folate concentration produced was 91.2 ng/ml and the values ranged from 2.4 to 340.6 ng/ml. A total of 18 isolates (52.9%, 5 isolates from cheeses samples and 13 isolates from goat´s milk samples) were able to have produced very high levels of natural folates (more than average value over (91.2 ng/ml) of total natural folates, being 5 isolates from cheeses samples and 13 isolates from goat´s milk samples. The mean value of total folate produced by isolates from goat´s milk samples were 98.4 ng/ml and by isolates from cheeses samples were 73.8 ng/ml. The average of extracellular concentrations was 25.8 ng/ml and the values ranged from 1.1 to 227.7 ng/ml. The mean value of intracellular concentrations was 65.3 ng/ml, ranging from 1.3 to 150.1 ng/ml. One The isolate 254 from a goat´s milk sample was the best folate producer, yielding 340.6 ng/ml total folate (EC = 227.7 ng/ml and IC = 112.9 ng/ml). The least folate producer was isolate 367 from a cheese sample, yielding 2.4 ng/ml (EC = 1.1 ng/ml and IC = 1.3 ng/ml). Even though some isolates were able to grow without riboflavin, none were able to produce this vitamin. The lactic acid bacteria isolatesd in this study showed good results for folate production and probably they will have good potential to be used in the production of a variety of bioenriched foods and are currently being identified.