Physiological and Biochemical Characteristics and the Biotechnological Potential of Hydrolytic Haloalkalitolerant Bacteria of Soda Sludge Storage

— The peculiarities of manifestation of hydrolytic activity of haloalkalitolerant bacteria Pseudomonas peli 3-T, Microbacterium kitamiense 16-DB, and Bacillus aequororis 5-DB, isolated from the ground of the territory of soda sludge storage and the soda sludge of the operating sludge reservoir of AO Berezniki Soda Plant (Perm krai, Russia) were studied. It was demonstrated that the maximum activities of extracellular lipases and amylases of three bacteria studied were manifested at pH 11 and a high concentration of sodium chloride (50–200 g/L). The cultivation of P. peli 3-T on a mineral medium with 0.5% glycerol (a source of carbon) and 0.03% urea (a source of nitrogen) allows us to obtain a biomass (6.9 g/L) and activity of extracellular (1.26 U/L) and cell-associated lipase (3.02 U/mg dry cells) with a high economic coefficient of substrate consumption (138%). The efficiency of immobilization of P. peli 3-T and B. aequororis 5-DB cells for use in lipid and starch biotransformation was demonstrated. The P. peli 3-T cells immobilized by adsorption on kaolin and entrapped into barium alginate and agarose gel preserved from 40.4 to 63.8% of the activity of cell lipase in the suspension. The B. aequororis 5-DB cells immobilized by adsorption on kaolin preserved 42.5% of lipase and 90.7% of amylase activity as compared with the initial ones. At the same time, the activities of the studied P. peli 3-T and B. aequororis 5-DB enzymes were preserved during six consecutive reactions. The amylase activity of immobilized M. kitamiense 16-DB cells during adsorption on kaolin and chitosan decreased to 2.7–3.5% of the initial one and was completely inhibited during immobilization by the entrapment into barium alginate or agarose gels.