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Aims: Development of probiotic beverages using previously isolated probiotic strains; Lactobacillus plantarum MF405176.1 and Lactobacillus curieae MF405178.1 in finger millet and banana flour substrates, respectively and monitor the microbiological, physicochemical and sensory properties of formulated probiotic beverages. Place and Duration of Study: Food Technology Section, Industrial Technology Institute, Colombo, Sri Lanka. Between November 2017 to April 2018. Methodology: Moisture content reduced (9 < 10%) finger millet (ravivar.)and banana (ambulnadee var.) flour were weighted seperately (25 g each), suspended in individual containers consisting of 100 ml potable water (n=6) and homogenised to obtain slurries. The slurries were sterilized (121 ± 1oC for 15 min) and cooled (35 ± 1oC) prior to inoculation of starter cultures. Previously isolated, freeze dried probiotic strains; L. plantarum MF405176.1 and L.curieae MF405178.1 were inoculated in to finger millet and banana slurries, respectively at probiotic cell concentration of 1010 CFU/ml. Slurries were allowed to ferment (37 ± 1°C) until the pH reaches < 3.5. Throughout fermentation,pH was monitored hourly, while probiotic cell viability was measured at every 4h. Final products were evaluated for viable probiotic cell count, chemical composition (protein, fat and ash content), physical properties (pH, moisture, total soluble solids and titrable acidity), microbiological quality (aerobic plate count, Yeasts and Mould count, Coliform and Escherichia coli), shelf-life (for 5 weeks at 4 ± 1°C) and Sensory properties (color, odor, appearance, texture and overall acceptability using 9 point hedonic scale). Results: Gradual increment of probiotic cell count with fermentation time was observed in both beverages. Compared to their respective controls, significant difference (P = .05) in physical properties (total soluble solids, titrable acidity and pH) and significant increment (P = .05) in chemical properties (fat and protein content) was observed in both beverages. Finger millet based probiotic beverage containing L. plantarum MF405176.1 exhibited better physical, chemical properties and higher acceptability. Further it demonstrated better shelf life compared to banana based beverage containing L. curieae MF405178.1. Both products could sustain the viability of probiotic starter cultures up to 109 CFU/mleven at the end of 5th week of shelf life period thus demonstrated the compatibility of finger millet and banana flour as ideal prebiotic substrates for development of probiotic food. Conclusion: Study highlighted the prebiotic potentiality of finger millet and banana flour for the development of dairy free probiotic food. It confirms the behavior of new probiotic strains L. plantarum MF405176.1 and L.curieaeMF405178.1 as starters in lactic acid fermentation.

This study evaluates the oral toxicity of five probiotic strains recently isolated from fermented flour of finger-millet (Eleusine coracana) varieties of Sri Lanka. Probiotic strains; Lactobacillus plantarum MF405176, Lactobacillus fermentum MF033346, Lactococcus lactis subspecies lactis MF480428, Enterococcus faecium MF480431and Pediococcus acidilactici MF480434 were evaluated for acute and sub-chronic oral toxicity in Wistars. Three individual doses (108 CFU/g, 1010 CFU/g and 1012 CFU/g) of each probiotic strain at single oral dose of 5000 mg/kg bw were orally administered to rats and observations were done till 14th day. Since no animals demonstrated signs of toxicity as a result of the administrated probiotics strains, repeated dose sub-chronic oral toxicity study was conducted by oral administration of three doses (108 CFU/g, 1010 CFU/g, 1012 CFU/g) of each probiotic strain at 1000 mg/kg bw/day for consecutive 90 days. Administration of probiotic strains to rats did not caused mortality in any of the tested doses. No changes in animal behavior, feed or water intake and negative effects on body weight observed. Probiotic feeding did not cause changes in analyzed biochemical and hematological parameters attributed to toxicity. Bacteremia, bacterial translocation and histopathological changes in rat organs were not observed. No significant difference in liver enzymes observed in treatment groups compared to control. In conclusion, all tested probiotic strains are nonpathogenic therefore could be considered as safe for human consumption.

This study aims to isolate and identify lactic acid bacteria from fermented flour of selected finger millet varieties grown in Sri Lanka and to evaluate their probiotic attributes and bioactive properties in vitro. Fifteen lactic acid bacteria were isolated from three varieties of fermented finger millet flour namely ravi, raavana and oshadha. These isolates were screened for phenotypical and biochemical characteristics. The selected isolates were identified by 16 S rRNA sequencing as Bacillus cereus (five strains), Streptococcus lutetiensis, Lactobacillus plantarum, Lactobacillus fermentum (two strains), Brevibacillus borstelensis, Paenibacillus species, Lactococcus lactis subspecies lactis, Enterococcus faecium, Pediococcus acidilactici, and Enterococcus lactis, and their partial sequences were deposited in GenBank. Among them, five isolates including two isolates, L. plantarum MF405176.1 and L. fermentum MF033346.1 isolated from ravi; two isolates, L. lactis MF480428.1 and E. faecium MF480431.1 isolated from raavana; and P. acidilactici MF480434.1 isolated from oshadha varieties respectively, exhibited in vitro safety attributes and could tolerate acid, gastric juice, bile, salt, phenol, and temperature under simulated gastric conditions, and also were susceptible to antibiotics tested. Further, they demonstrated bactericidal activity against both drug-sensitive and multidrug-resistant pathogens. Among the selected isolates, L. plantarum MF405176.1 demonstrated highest hydrophobicity and adhesion to both colon colorectal adenocarcinoma and colon colorectal carcinoma cell lines. L. lactis subspecies lactis MF480428.1 exhibited the highest auto-aggregation and 2, 2, diphenyl-1-pricrylhydrazyl free radical scavenging activity. P. acidilactici MF480434.1 demonstrated the lowest IC50 values against HCT-116 and HT-29 cells. None of the LAB isolates could assimilate > 10% cholesterol in vitro.

This study aimed at isolating and identifying lactic acid bacteria (LAB) with probiotic potential from fermented flour of selected banana varieties grown in Sri Lanka and evaluating their probiotic and safety attributes in vitro. Ten lactic acid bacteria were isolated from six varieties of fermented banana flour, kolikuttu, seeni parakum, ambul nadee, ambum, seeni and anamalu. The isolates were screened for phenotypical and biochemical characteristics. The selected isolates were identified by 16 S rRNA sequencing as Enterococcus durans (two strains), E. gallinarum, E. hirae, E. faecium (two strains), Lactobacillus plantarum, L. curieae, Weissella cibaria and Pediococcus acidilactici and their partial sequences were deposited in NCBI. Among them, six isolates were selected based on the results of in vitro safety attributes and evaluated for their probiotic attributes. Three isolates, namely, E. durans MF405179.1, E. faecium MF574466.1 and L. curieae MF405178.1 isolated from kolikuttu, seeni parakum and ambul nadee, respectively demonstrated tolerance to acid, gastric juice, bile, salt, phenol and temperature under gastric conditions, and also showed susceptibility to tested antibiotics. Among the selected isolates, E. durans MF405179.1 demonstrated the highest hydrophobicity and auto-aggregation of 69.91 % and 76.53 %, respectively. Further, it exhibited highest adhesion to both HCT116 and HT29 cell lines demonstrating 72.5 % and 74.16 % adhesion, respectively. This is the first report of isolation and characterisation of LAB strains with probiotic potential from flour of banana varieties kolikuttu, seeni parakum, ambul nadee, ambum, seeni and anamalu grown in Sri Lanka.