Screening of lactic acid bacteria producing folate and their potential use as adjunct cultures for cheese bio-enrichment
FEMS MICROBIOLOGY LETTERS
Authors: Albano, Clara; Silvetti, Tiziana; Brasca, Milena
Abstract
Lactic acid bacteria (LAB) can be used to increase the folate in foods by in situ fortification. Seventy LAB were screened for their ability to produce folate during growth in de Man, Rogosa and Sharpe/M17 broth. Lactobacillus casei, Lactobacillus plantarum, Lactobacillus paracasei subsp. paracasei, Lactobacillus rhamnosus, Lactobacillus delbrueckii subsp. bulgaricus, Streptococcus thermophilus, Lactococcus lactis subsp. lactis, Enterococcus faecium and Enterococcus lactis were able to synthetize folates in the medium, even if to a different extent. The 47 folate-producing strains were further analyzed by microbiological assay, for total, extra and intracellular folate. Enterococcus faecium VC223 and E. lactis BT161 were able to produce in cultural medium 123,625.74 +/- 8.00 ng/ml and 384.22 +/- 5.00 ng/ml of folate, respectively. Five strains were further examined for their ability to synthesize folate in cheese. The folate content increased with ripening up to by 54% after 30 d when L. casei VC199 was used and up to 108% and 113% after 60 d, with L. paracasei SE160 and E. lactis BT161 respectively exceeding 100 ng/100g. Results encourage the use of specific LAB to obtain natural folate bio-enriched dairy products improving folate intake.
The Prevalence of Streptococcus Mutans with Different ABO Blood Groups Among Healthy College Students
OPEN DENTISTRY JOURNAL
Authors: Al-Mahmood, Sumayah; Al-Kaisy, Aedah Z.; Mahmood, Maha A.; Aldhaher, Zainab A.; Sabri, Abbas
Abstract
Objective: This study was conducted to determine the correlation between the occurrence of Streptococcus mutans (S. mutans) which is considered as the main pathogen responsible for the initiation and development of dental caries with blood groups and Rhesus (Rh) factor that are considered as a genetic predictor of having dental caries among healthy students. Methods: Saliva and blood samples were taken from 40 healthy students whose ages were between 19-23 years old in the College of Dentistry/Al-Iraqia University in Baghdad, Iraq. Estimation of the flow rate and pH was done for all the collected saliva samples within 5 min of saliva collection. Then, 100 mu L of saliva was cultured on Mitis salivarius bacitracin agar (MSBA) at 37 degrees C for 48 h. The colonies of S. mutans were identified by their morphology and biochemical tests. Later, 1 to 2 drops of blood were taken from each student's thumb to determine the blood group. Results: This study showed there was a greater prevalence of S. mutans among students of blood group A in contrast to the blood group O. In addition, Rh+ groups were dominant than Rh- groups among the study samples. Conclusion: S. mutans levels were higher in the blood group A followed by AB, B, O blood groups among the college students studied.