Faculty of Food Technology and Biotechnology, University of Zagreb
Abstract
Colostrum is the first milk produced by the mammary gland during the early postpartum period. In addition to nutrients, antimicrobial and growth factors, bovine colostrum contains valuable microflora, including members of the genera Lactobacillus and Bifidobacterium, which have been used widely in probiotic food. The aim of this work is to identify and quantify the microflora of colostrum samples from two Holstein dairy cows on the first three postpartum days through culture-dependent 16S rRNA gene sequencing and length heterogeneity polymerase chain reaction (LH-PCR) techniques, using an adapted method to extract the total DNA. Twenty-nine strains isolated in synthetic media were identified by their 16S rRNA gene sequences, revealing two potential probiotic strains (Lactobacillus casei and Bifidobacterium pseudolongum). Colostrum samples were subjected to LH-PCR analysis to obtain fingerprint profiles of the microflora. Lactobacillus casei was the main species present in the samples. The probiotic potential of these bacteria for use in fermented and functional foods remains to be evaluated.Kolostrum je prvo mlijeko, koje proizvodi mliječna žlijezda tijekom ranog postpartalnog razdoblja. Osim što sadrži hranjiva, antimikrobne tvari i hormone rasta, kravlji kolostrum sadržava dragocjenu mikrofloru, uključujući sojeve rodova Lactobacillus i Bifidobacterium što se koriste u proizvodnji probiotičke hrane. Svrha je ovoga rada bila identificirati i kvantificirati mikrofloru u uzorcima kolostruma dvaju Holstein mlječnih krava, uzetih tijekom prva tri dana postpartalnog razdoblja. Mikroorganizmi su određeni sekvenciranjem 16S rRNK gena i LH-PCR metodom kojom se ekstrahira ukupna DNK. U sintetičkoj je podlozi izolirano dvadeset i devet sojeva, identificiranih pomoću sekvencija 16S rRNK gena, te su izdvojena dva potencijalno probiotička soja (Lactobacillus casei i Bifidobacterium pseudolongum). Uzorci su kolostruma analizirani LH-PCR metodom kako bi se utvrdio DNK profil mikroflore, te je utvrđeno da u uzorcima prevladava vrsta Lactobacillus casei. Probiotička svojstva ove bakterije za proizvodnju fermentiranih i probiotičkih proizvoda tek treba istražiti
