Desiccation responses and survival of Sinorhizobium meliloti USDA 1021 in relation to growth phase, temperature, chloride and sulfate availability

Department of Microbiology, University of Massachusetts, Amherst, MA 01003, USA.
Letters in Applied Microbiology (Impact Factor: 1.66). 03/2006; 42(2):172-8. DOI: 10.1111/j.1472-765X.2005.01808.x
Source: PubMed


To identify physical and physiological conditions that affect the survival of Sinorhizobium meliloti USDA 1021 during desiccation.
An assay was developed to study desiccation response of S. meliloti USDA 1021 over a range of environmental conditions. We determined the survival during desiccation in relation to (i) matrices and media, (ii) growth phase, (iii) temperature, and (iv) chloride and sulfate availability.
This study indicates that survival of S. meliloti USDA 1021 during desiccation is enhanced: (i) when cells were dried in the stationary phase, (ii) with increasing drying temperature at an optimum of 37 degrees C, and (iii) during an increase of chloride and sulfate, but not sodium or potassium availability. In addition, we resolved that the best matrix to test survival was nitrocellulose filters.
The identification of physical and physiological factors that determine the survival during desiccation of S. meliloti USDA 1021 may aid in (i) the strategic development of improved seed inocula, (ii) the isolation, and (iii) the development of rhizobial strains with improved ability to survive desiccation. Furthermore, this work may provide insights into the survival of rhizobia under drought conditions.

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Available from: Jan A C Vriezen,
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    • "Due to spore forming capability Bacillus is one of the most important genera among PGPR which help in the formation of stable bioinocluant. Various environmental factors generate stress that affects the activity or potential of the local micro-flora (Vriezen et al. 2006). Therefore, study of phosphate-solubilizing Bacillus under stress conditions from the rhizosphere is the key area to screen new strains that has immense potential to be used as bioinoculant in the agriculture. "
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    SpringerPlus 06/2014; 3(1):312. DOI:10.1186/2193-1801-3-312
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    • "This difference in the behavior of the two bacterial species is not surprising because the optimal growth phase for desiccation survival has been found to be largely dependent on the micro-organism (Boumahdi et al., 1999). Nevertheless, stationary phase cells are generally more resistant to physical stresses such as drying (Mary et al., 1986; Vriezen et al., 2006). This is due to the stress response triggered by carbon starvation and exhaustion of available food sources (Morgan et al., 2006 "
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    ABSTRACT: This work deals with optimising the cell survival of rhizobacteria encapsulated in alginate beads filled with starch. Immobilisation of rhizobacteria was done by dripping alginate-starch solution mixed with rhizobacteria into a calcium solution. Beads were analysed based on matrix formulation, bacteria growth phase, osmoprotectants and nature of calcium solution. Maximum cell recovery was obtained on Raoultella terrigena grown in medium supplemented with trehalose and calcium gluconate as gelling agent. Furthermore, dried beads containing Azospirillum brasilense presented 76% of viable cells after one year of storage. The survival of rhizobacteria during the bioencapsulation process can be improved by incorporating starch on beads composition, varying the growth phase of cells and using trehalose in growth culture medium. This work provides a selection of appropriate methods to improve the surviving rate of encapsulated cells during their production and long-term storage (∼1 year at 4°C).
    Journal of Microencapsulation 02/2012; 29(6):532-8. DOI:10.3109/02652048.2012.665090 · 1.59 Impact Factor
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    • "Many conditions have been identified that affect the survival of agriculturally important Rhizobiaceae during desiccation (Vincent et al. 1962; Bushby and Marshall 1977 Some factors affecting the survival of root nodule bacteria on desiccation; van Rensburg and Strijdom 1980; Dye 1982; Salema et al 1982 Death of rhizobia on inoculated seed, 1982 Rupture of nodule bacteria on drying and rehydration; Kremer and Peterson 1983; Mary et al. 1985, 1986; Kosanke et al. 1992; Smith 1992; Chenu 1993; Boumahdi et al. 1999; Estrella et al. 2004; Kaci et al. 2005; Vriezen et al. 2006). These conditions include the intrageneric differences to cope with desiccation stress affecting survival (vanRensburg and Strijdom 1980; Mary et al. 1985, 1986; Trotman and Weaver 1995; Boumahdi et al. 1999; Sadowski and Graham 1998). "
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