title: Technological properties and probiotic potential of Lactobacillus fermentum strains isolated from West African fermented millet dough.
abstract: BACKGROUND
  Throughout Africa, food fermentations are still driven by indigenous microorganisms which influence the nutritional, organoleptic and safety of the final products. However, for improved safety, consistent quality and beneficial health effects, a trend has emerged which involves the isolation of indigenous strains from traditional fermented products to be used as functional starter cultures. These functional starter cultures possess inherent functional characteristics and can contribute to food quality and safety by offering one or more organoleptic, nutritional, technological or health advantage (probiotics). With the aim of selecting potential probiotic starter cultures, Lactobacillus fermentum strains isolated from fermented millet dough were investigated for technological properties and probiotic traits in-vitro.
  
  
  RESULTS
  A total of 176 L. fermentum strains were assessed for technological properties including rate of acidification, exopolysaccharide production and amylase activity. Following this, 48 strains showing desirable technological properties were first screened for acid resistance. Sixteen acid resistant strains were assessed for additional probiotic properties including resistance to bile salts, bile salt hydrolysis, antimicrobial property, haemolysis and antibiotics resistance. L. fermentum strains clustered into 3 groups represented by 36 %, 47 % and 17 % as fast, medium and slow acidifiers respectively. About 8 %, 78 % and 14 % of the strains showed strong, weak and no exopolysaccharides production respectively. Amylase activity was generally weak or not detected. After exposure of 48 L. fermentum strains to pH 2.5 for 4 h, 16 strains were considered to be acid resistant. All 16 strains were resistant to bile salt. Four strains demonstrated bile salt hydrolysis. Antimicrobial activity was observed towards Listeria monocytogenes and Staphylococcus aureus but not E. coli and Salmonella enteritidis. Lactobacillus fermentum strains were generally susceptible to antibiotics except 6 strains which showed resistance towards streptomycin, gentamicin and kanamycin.
  
  
  CONCLUSIONS
  In vitro determination of technological and probiotic properties have shown strain specific difference among L. fermentum strains isolated from fermented millet dough. Sixteen (16) L. fermentum strains have been shown to possess desirable technological and probiotic characteristics in vitro. These strains are therefore good candidates for further studies to elucidate their full potential and possible application as novel probiotic starter cultures.
authors.affiliation: Department of Applied Biology, Faculty of Applied Sciences, University for Development Studies, P. O. Box 24, Navrongo Campus, Navrongo, Ghana. jowusukwarteng@yahoo.co.uk.
authors.forename: James
authors.initials: J
authors.lastname: Owusu-Kwarteng
authors.affiliation: Department of Nutrition and Food Science, University of Ghana, P. O. Box 134, Legon-Accra, Ghana. ktanode@ug.edu.gh.
authors.forename: Kwaku
authors.initials: K
authors.lastname: Tano-Debrah
authors.affiliation: Department of Applied Biology, Faculty of Applied Sciences, University for Development Studies, P. O. Box 24, Navrongo Campus, Navrongo, Ghana. fakabanda@gmail.com.
authors.forename: Fortune
authors.initials: F
authors.lastname: Akabanda
authors.affiliation: Department of Food Science, University of Copenhagen, Rolighedsvej 26, DK 1958, Frederiksberg C, Denmark. lj@food.ku.dk.
authors.forename: Lene
authors.initials: L
authors.lastname: Jespersen
mesh_terms: D000349:Africa; D005285:Fermentation; D005524:Food Technology; D066298:In Vitro Techniques; D052197:Limosilactobacillus fermentum / Q000737:chemistry / Q000145:classification / Q000302:isolation & purification*; D008826:Microbial Sensitivity Tests; D000066928:Millets / Q000382:microbiology*; D019936:Probiotics / Q000032:analysis* / Q000145:classification