Large-Scale Production of Rhizobium meliloti on Whey

Abstract

Whey, a by-product of the cheese industry, can sustain the growth of fast-growing rhizobia. To avoid any latency of growth, rhizobial inoculum must be prepared under inducing conditions. In unsupplemented whey, * Corresponding author. t Contribution 295 of the Research Station, Agriculture Canada, Sainte-Foy, Quebec.

Use of Potato Extract Broth for Culturing Root-Nodule Bacteria

“…1), but the slow-growing Bradyrhizobium species required a longer incubation period, similarly to results reported earlier (Roughly, 1970;Burton, 1979;Ben Rebah et al, 2007). e numbers of the viable cells (c.f.u) of the rhizobia in PEGB and PESB accounted for 1.2×10 10 to 4.9 × 10 10 mL -1 in the case of the fast-growing rhizobia and 6.4× 10 9 c.f.u ml -1 in the case of B. japonicum B3S, (Table I) were comparable or higher than those obtained in other studies on culturing of the rootnodule bacteria in various liquid media (Gulati, 1979;Bioardi and Ertola, 1985;Bissonnette et al, 1986;Ben Rebah et al, 20007). It has been found that the composition of growth media can have a significant e ect on some characteristics of rhizobia.…”

“…It has been found that the composition of growth media can have a significant e ect on some characteristics of rhizobia. For instance, high concentrations of yeast extract (> 3.5 g L -1 ) in liquid media can decrease nodulation potential of root-nodule bacteria grown in such media (Bissonnette et al, 1986;Stephens and Rask, 2000). For this reason nodulation of alfalfa, pea and soybean seedlings inoculated with the cultures of their specific rhizobia grown in PEGB and in YEMB was compared (Table III).…”

“…For example, yeast extract as a source of nitrogen, vitamins and other micronutrients is commonly used to prepare various media for culturing of rhizobia in research studies and for commercial purposes (Roughly, 1970;Vincent, 1981;Stephens and Rask, 2000). Many other substrates or industrial and agricultural by-product such as: proteolyzed pea husks (Gulati, 1979), corn steep liquor (Burton, 1979), malt extract (Bioardi and Ertola, 1985), cheese why (Bissonnette et al, 1986), or even wastewater sludge (Ben Rebah et al, 2007) have been proposed as media for rhizobial biomass production. e aim of this work was to examine if potato extract can be used as a basic source of nutrients for cultivation of root-nodule bacteria in liquid cultures.…”

High Survivability of Cheese Whey-Grown Rhizobium meliloti Cells upon Exposure to Physical Stress

“…R. meliloti A2 (2), which is a very effective strain for inoculation, was used in this study. Cultures were maintained at 4°C on slants of whey agar, and the fermentation conditions were the same as described previously (1).…”

“…To improve the quality of inoculants, numerous investigators have looked for the best growth medium for the massive production of rhizobia (1,6,20). Considerable work has also been conducted with peat-based inoculants to increase the viability of rhizobia on seeds (4,5,18).…”