Effect of drying on bioremediation bacteria properties

Abstract

Bioremediation bacteria with drought-resistance characteristics were selected and compared to a collection of 10 strains selected only for their bioremediation properties. Twenty-six strains were selected from dried diesel-polluted soil, and they exhibit a better level of survival during drying, compared to collection bioremediation strains (two orders of magnitude difference). The lyophilization process does not affect the strains' ability to grow on xenobiotic compound when measured immediately after drying. However, collection bioremediation strains selected only for their bioremediation properties lose up to 80% of their properties when stored at 25 degrees C for 15 d, but the strains selected for their drought resistance lose their properties to a lesser extent during the same period. The maximal growth rate and the rate of xenobiotic degradation of the still-active cells are not affected by the drying process.

Ralstonia metallidurans, a bacterium specifically adapted to toxic metals: towards a catalogue of metal-responsive genes

“…The knowledge about the mechanisms of resistance to heavy metals and especially their regulation stimulated further work in microbial ecology [46–51] and in environmental biotechnology [52]. Industrial applications of metal‐resistant bacteria and their genes include the use of biosensors for monitoring the concentration of heavy metals in a variety of substrates and soils [53–58], the development of bioreactors to remove heavy metals from polluted effluents or soils [59,60], and bioaugmentation [61] and phytoremediation [62] (Y. Wang, W. Hai, J. Vander Leyden and M. Mergeay, unpublished).…”

Stable biofilms of Rhodococcus erythropolis T902.1 in draining pavement structures for runoff water decontamination

“…The choice of this desiccation-tolerant strain, previously described by Weekers et al (1998Weekers et al ( , 1999 in other culture conditions, could explain this limited death despite the harsh conditions implemented in both tests. Considering that the longest drought period recorded in Belgium lasted 36 days (Institut Royal M et eorologique, 2007), and that the draining system will probably always retain a small quantity of water in the structure (cf.…”

“…Moreover, the species R. erythropolis can preserve its membrane integrity and degradation ability under different environmental stress conditions such as desiccation (Weekers et al, 1998(Weekers et al, , 1999, low nutrient content (Kuyukina and Ivshina, 2010a), high salinity de Carvalho et al, 2014), extreme temperatures or pH (de Carvalho, 2012). It can also form stable biofilms by means of its high hydrophobic cell envelope containing mycolic acids (Schreiberov a et al, 2012).…”

An Approach to Desiccation-Tolerant Bacteria in Starter Culture Production

“…In this strategy, desiccation tolerance is used as the main selective pressure and is considered as the most important property for the production of starter cultures. Therefore products such as a starter culture for the bioremediation of xenobiotic-contaminated soils are stored in a dry form (Weekers et al, 1999a;Weekers et al, 1998;Weekers et al, 1996). The xenobiotic catabolic activity may be introduced afterward into the drought-tolerant strains by the mean of natural conjugation in order to broaden the potential applications of the product (Weekers et al, 1999b).…”