In vitro adhesion property and competition against enteropathogens of Lactobacillus strains isolated from Thai infants

Adhesion to the intestinal epithelium is considered to be one of the selection criteria for probiotics strain. In this study, the adhesion of four different Lactobacillus strains with potential probiotics properties, i.e. L. paracasei MSMC39-1, L. casei MSMC39-3, L. salivarius MSMC105-3 and L. plantarum MSMC171-1, was studied using Caco-2 cell line as an in vitro model for intestinal epithelium. Among four different Lactobacillus strains, L. salivarius MSMC105-3 was the most adhesive strain showing about 3.5 percent of adhesion index. Thus, this strain was selected to examine for its ability to inhibit the adhesion of pathogenic Salmonella Typhi DMST5784 and Shigella dysenteriae DMST15111 to Caco-2 cells. The results showed that L. salivarius MSMC105-3 whole cell and its cell-free culture supernatant could inhibit the adhesion of pathogens. The results from this study indicated that both L. salivarius MSMC105-3 itself and its substances secreted into culture supernatant had the ability to reduce the adhesion of enteropathogens to Caco-2 cells

High Potential Decolourisation of Textile Dyes from Wastewater by Manganese Peroxidase Production of Newly Immobilised Trametes hirsuta PW17-41 and FTIR Analysis

Coloured wastewater from the textile industry is a very serious global problem. Among 16 different white-rot fungal isolates, Trametes hirsuta PW17-41 revealed high potential for decolourisation of mixed textile dyes (Navy EC-R, Ruby S3B and Super Black G) from real industrial wastewater samples. The efficiency of dye decolourisation was evaluated using the American Dye Manufacturers’ Institute (ADMI) standard methodology. The suitable support for fungal mycelium immobilisation was nylon sponges. The optimal dye decolourisation (95.39%) was achieved by using palm sugar and ammonium nitrate as carbon and nitrogen sources, respectively. The initial pH was 5 and the agitation speed was 100 rpm at 30 °C. The ADMI values of textile dyes decreased from 2475 to 114 within two days, reducing the treatment time from seven days before optimisation. The major mechanism of dye decolourisation was biodegradation, which was confirmed by UV–visible and FTIR spectra. Manganese peroxidase (MnP) (4942 U L−1) was found to be the main enzyme during the decolourisation process at an initial dye concentration of 21,200 ADMI. The results indicated the strong potential of immobilised fungal cells to remove high concentrations of textile dyes from industrial wastewater and their potential ability to produce high MnP and laccase activities that can be used in further application