Isolation And Identification Of Lactic Acid Bacteria From Bee Bread And Its Application In Fermentation Of Bee Pollen

Bee bread is the admixture of bee pollen, honey and secretion of bee, which then undergo fermentation by abundant microbe. The isolating and screening of Lactic Acid Bacteria(LAB)from bee bread were carried out to study the application in the fermentation of bee pollen. The results were summarized as follows:1. A total of39LAB isolates were recovered and purified from bee bread sample.16isolates were primarily confirmed to belong to the LAB group by Gram-positive, no catalase activity, and positive results for glucose fermentative ability. Then three strains L4, L6, L7were screened as their excellent characteristics in acid production. With API50CH system, L4, L6, and L7were identified as Lactobacillus plantarum, Lactobacillus casei ssp casei and Lactobacillus delbrueckii ssp delbrueckii, respectively. They could grow in the condition of pH between5.5and7.0; The most appropriate temperature for the growth of L4was30℃, while that of L6and L7were35℃. Their logarithmic growth phase and stable phase was6h-8h and14h after culturing, respectively.2. Bee pollen was fermented by single bacteria(L4, L6and L7, respectively). It was found that L4was the optimum strain for fermentation of bee pollen, considering the growth of strains in the bee pollen and the pH of the product.3. The mixed culture by L4and Monascus was studied. The results showed that the growth of L4was not advanced when L4and Monascu were inoculated at the same time, while L4could grow faster when Monascus was incubated beforehand. The best culture mode was:L4was incubated in MRS liquid medium for12h; Monascu inoculum was incubated in fermentation liquor for7d; then they were both inoculated into bee pollen.4. With the viable count of L4and sensory evaluation as indices, L9(34) orthogonal experiment of the four factors including the inoculation amount of L4, the addition amount of Monascu fermentation liquor, the addition amount of water and fermentation temperature was operated. The optimal pollen fermentation condition was:inoculation amount of L413%, addition amount of Monascu fermentation liquor10%, that of water25%and fermentation temperature33℃. The optimal fermentation period was5d. Rape bee pollen, fermented by Lactobacillus plantarum, except for the smell of fish and the bitter taste, and rich in probiotics, improved its nutritional value.5. In vitro digestibility of bee pollen and product was detected as the simulation digest condition of HCl and pepsin. It was found that wall-broken rate of product was higher than that of bee pollen during the same time, which suggested that LAB fermentation could help to improve the digestibility of pollen.