Three food microorganisms a fungus geotrichum

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Three food microorganisms, a fungus ( Geotrichum candidum ) and two bacteria ( Lactococcus lactis subsp. cremoris and Lactobacillus delbrueckii subsp. bulgaris ) are used as starters in the dairy technology. Clair et al. (2012) found all three microorganisms to be more sensitive to Roundup than to glyphosate alone. In an in vitro study, the nitrogen fixating bacteria, Azotobacter vinelandii , showed a higher degree of sensitivity towards glyphosate than Azotobacter chroococcum did (Santos and Flores, 1995). In soil samples, Busse et al. (2000) observed an increase in total and viable bacteria after glyphosate addition, and especially Arthrobacter, Pseudomonas, Xanthomonas and Bacillus spp. increased in population. Difference in glyphosate tolerance between bacteria cultured in soil and in soil-free media might be explained by the chemical properties of glyphosate. Glyphosate binds easily to soil particles, which leaves the compound unable to exert its herbicidal effects (Borggaard and Gimsing, 2008; Duke et al., 2012).
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17 Tsui and Chu (2003) investigated whether POEA also accounted for the toxicity of Roundup to microorganisms. Bacteria ( Vibrio fischeri ) and protozoa ( Tetrahymena pyriformis and Euplotes vannus ) had more or less similar sensitivities towards Roundup. For the same species, POEA showed considerably lower toxicity levels, and generally, glyphosate IPA salt was least toxic. Based on these findings it become obvious, how important it is to investigate whole Roundup formulations. In formulations, it is always important to know the individual toxicities of the different compounds but also their combined effects, as they might influence each other. Changes in gut microbiota with respect to glyphosate Potential levels of glyphosate in gut As the overall objectives of this study are to investigating possible effects of glyphosate on microorganisms in livestock, it is useful to calculate, which levels it is likely to obtain in the gut. Two scenarios are presented below, one for pigs and one for cows. Numbers presented in Table 4 Fejl! Henvisningskilde ikke fundet. , are calculated based on feeding pigs a diet containing only barley or soybean meal. If the soybean meal and barley contain MRL of glyphosate allowed in the EU (20 mg/kg), the residues in the gut would be between 0.005 and 0.019 mg/ml, based on the assumptions made. Table 4. Estimated glyphosate concentrations in the gut of pigs, fed a diet containing the MRL of glyphosate for barley and soybean meal (20 mg/kg). Calculated by Martin Tang Sørensen. In addition to Table 4, Table 5 shows which glyphosate concentrations it might be able to obtain in the gut of cows, assumed that they are fed a diet, where 50 % is composed of soybean meal and barley, and MRL of glyphosate are present in these feedstuffs. Compared to pigs, lower levels of glyphosate (from 0.0022-0.003 mg/ml) can be present in the different segments in cows, mainly because of the lower percentage of concentrate in the feed ration.
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