WHEY BASED CULTURE MEDIA FOR THE PRODUCTION OF SELENIUM NANOPARTICLES RICH PRODUCT BY THREE LACTIC ACID BACTERIAL STRAINS.

Abstract

The ability of three LAB strains namely, L. brevis, L. plantarum and P. acidilactici to grow and produce SeNPs in MRS or whey media supplemented with 100 or 200 ppm of Se(IV) as sodium selenite (Na2SeO3) was investigated. The presence of Se(IV) in the media retarded the bacterial growth in the first six hours of incubation thereafter, the bacterial growth gradually increased up to 72 hr. P. acidilactici was more tolerable to the inhibitory effect of Se(IV) than the other two strains. Although MRS media was more suitable for the growth of the three LAB strains, as estimated by the reduction of media pH and increase of absorbance compared to whey media, both media showed significantly similar conversion rate (98-100%) of Se(IV) to SeNPs at the end of the incubation period (72 hr). L. brevis, produced smaller SeNPs (125.7 nm) followed by L. plantarum (140.7 nm) and P. acidilactici (176.6 nm). The obtained data demonstrate the possibility of using the whey as a source of low-cost culture media for the production of milk whey based product rich in SeNPs with the assistant of the environmentally friendly LAB for different usage, i.e. as a feed supplement for livestock production.