Untitled

Abstract

Background: Successful application of growth inhibition techniques for quantitative determination of bacteriocins relies on the sensitivity of the applied indicator microorganism to the bacteriocin to which is exposed. However, information on indicator microorganisms' performance and comparisons in bacteriocin determination with bioassays is almost non-existing in the literature. The aim of the present work was to evaluate the parameter "indicator microorganism" in bioassays carried out on solid -agar diffusion assay-and liquid -turbidometric assay-substrates, applied in the quantification of the most studied bacteriocin nisin.

Beyond De-Foaming: The Effects of Antifoams on Bioprocess Productivity

“…We have observed that antifoams can affect the growth of yeast cells, and similar observations have also been made for bacteria[10, 19]. Increased growth rates of cultures have been found to lead to increased productivity[38, 39] which is true for our observations for 0.6% Antifoam A, 1% J673A, 1% P2000 and 1% SB2121 cultures which grew at similar or higher growth rates than the control cultures and produced a higher yield of GFP.…”

Cultivation, isolation and characterization of bacteriocin from fresh cow milk and meat samples obtained from Lapai Market in Niger State Nigeria

“…Nisin Standardization Protocol: Nisin Standard was prepared according the methods of Papagianni et al (2006) by adding 0.1g of nisin to solution (10 ml 0.02 N HCl and 0.75% NaCl) and steam sterilized at 121 O C for 15minutes at 15psi and tagged standard nisin solution(10 5 UI/ml). From this standard solution, 0.2, 0.4, 0.6, 0.8 and 1.0 concentrations with index factor of 10 3 IU/mL were prepared and used to plot standard nisin concentrationabsorbance(@450nm) chart with R 2 = 0.959.…”

Optimization of the yield of bacteriocin-like substance (BLIS) produced by <i>Pediococcus pentosaceus</i> and its application as food bioconservative

“…There are cations (Ca Nowadays, it is difficult to find comparison in the literature about using bioassays performed only in solid (agar) medium as presented in this work, meanwhile it is possible to find more easily tests performed either in solid (agar diffusion assay) or in liquid (turbidimetry) media. A major difficult in bacteriocin research is obtaining accurate results using bioassays, which are based in inhibition activity produced in a sensitive microorganism (Rasch, & Knochel, 1998;Papagianni, Avramidis, Filioussis, Dasiou, & Ambrosiadis, 2006).…”

“…Lb. curvatus ATCC 51436 and P. acidilactici ATCC 25740, were sensitive to very low bacteriocin (nisin) concentrations and produced a linear type of response either in agar-medium (agar diffusion assay) or liquid-medium (turbidometric assay) (Papagianni, Avramidis, Filioussis, Dasiou, Ambrosiadis, 2006).…”

“…Agar diffusion assay, that produces halos where growth is inhibited, is undoubtedly the most commonly used method to determine bacteriocin activity (Bouksaim, Lacroix, Audet, & Simard, 2000). However, this methodology is dependent on the bacteriocin diffusing through the agar, it is time-consuming and also relies on human interpretation when zones of inhibition are unclear or not perfectly circular (Papagianni, Avramidis, Filioussis, Dasiou, & Ambrosiadis, 2006). The possibility of unspecific reaction between the active substance present in the tested culture and the agarmedium should also be considered.…”