CREATION OF ANTIFUNGAL PREPARATION ON THE BASIS OF <i>PSEUDOMONAS AUREOFACIENS </i>BACTERIA CULTIVATED ON THE POST-ALCOHOL DRAFF UNDER DIFFERENT PARAMETERS OF CULTIVATION
Utilization of post-alcohol draff, main waste of ethyl alcohol production from grain raw materials, is a serious environmental and economic problem. This problem can be solved by growing bacteria (including those belonging to genus Pseudomonas ) in a medium with a liquid fraction of the post-alcohol draff (LFPAD), followed by cultural liquid use for plants treatment to defense against phytopathogens. The aim of this work was to study the parameters of Pseudomonas aureofaciens bacteria cultivation on LFPAD, which help to obtain the maximum biomass in laboratory experiment. Accumulation of Pseudomonas aureofaciens biomass was studied in bacteria, applied into LFPAD containing medium. Bacteria cultivation was carried out under static conditions and on a thermo-regulated shaker at 28 ° C for 27 hours. The following parameters were varied during the experiment: (1) initial pH of the medium (from 4.3 to 8.0), (2) concentration of added salts (0.5 to 1.5 g/l KH2PO4 and 0.1 to 0,5 g/l MgSO4), and (3) medium mixing rate (from 100 to 220 rpm). It was revealed that largest biomass of Pseudomonas aureofaciens was formed after 19 23 hours cultivation (depending on variation of other parameters). The best medium in which the maximum growth and bacterial biomass formation occurred was LFPAD with initial pH 7.0 supplemented with 1.5 g/l KH2PO4. It is shown that medium mixing conditions are necessary for the maximum bacterial biomass formation. The optimum mixing rate was 150 rpm, regardless of medium pH. In a variant with pH 7.0 and mixing rate of 150 rpm, there was a maximum biomass yield with a reduced (19 h) cultivation time, which would save energy costs. The resulting cultural liquid can be used to produce a biopreparation with a high antifungal activity, which can be used for soil treatment to increase the beneficial microflora, as well as plants and seeds treatment, to protect against phytopathogenic fungi.