Growth of lactic acid bacteria on oilseed crop pea- and chickpea-based media

Abstract

Six strains of lactic acid bacteria isolated from different biotopes were cultivated on oilseed crop pea- or chickpea-based media, supplemented with the usual nitrogen supplements, yeast extract, meat extract or tryptic casein peptone. Growth was compared to that recorded on the widely used MRS and M17 media. All the media tested favoured growth of the selected strains, since the final c.f.u. gained at least 3 logs. Vegetal substrate (pea) appeared especially efficient for growth of a LAB species isolated from plants, Lactobacillus plantarum, illustrating the relationship between the supplementation used and the natural biotope of the LAB strain; during growth on oilseed crop pea- and chickpea-based media, the final c.f.u. was 0.58 and 1.28 log higher than the final cell numeration recorded on the reference medium MRS. The better efficiency of chickpea to stimulate LAB growth, if compared to oilseed crop pea, must be related to its higher protein content, 24.15 ± 0.1 and 28.2 ± 0.5% respectively. A vegetal substrate with high protein content can be therefore used to replace, at least partially, the usual nitrogen supplements.