Biotechnological potential of bacterial isolates separated from the microbiome of native plants of the Vologda region
Abstract
The study was conducted to isolate and functionally characterise bacteria in the rhizosphere and phyllosphere of native plants in the Vologda Region, which may be of interest for the development of regionally adapted biopreparations. The isolates were selected from species common in the region and capable of successful development in various biotopes: beaked parsley, creeping thistle, and cocksfoot. The isolates' ability to fix molecular nitrogen, transform phosphates, and exhibit cellulose and proteolytic activity was studied in the laboratory by culturing them on selective nutrient media. The indole-3-acetic acid (IAA) content in the isolate culture fluid was determined spectrophotometrically, and the amino acid composition was determined by high-performance liquid chromatography. The antagonistic activity of the isolates against phytopathogens (Fusarium, Trichoderma, and Erwinia) was determined by surface co-cultivation on LB (Luria-Bertani) medium. A series of laboratory experiments was conducted using valuable bacteria to evaluate the effect of isolate suspensions on the sowing characteristics of seeds and the growth parameters of seedlings of test objects – garden cress and barley. Among the 74 isolates selected from the rhizosphere and phyllosphere of native plants in the Vologda Region, EF-01-25 and KR-08-25 are of greatest interest for activating the growth of agricultural crops. These isolates synthesize IAA in amounts of 65.8-123.9 mg/L, exhibit the ability to fix molecular nitrogen and transform phosphates (phosphate mobilization efficiency of 111-225%), increase seed germination by 9-16%, shoot length by 21-37%, main root length by 12-31%, and root count by 15%. Additionally, 7 isolates (BodR-05-25, KF-10-25, BodF-01-25, BodF-06-25, BodR-03-25, BodR-07-25 and KR-04-25) with pronounced antagonism to Fusarium, Trichoderma and Erwinia, as well as 15 isolates (EF-04-25, EF-05-25, EF-07-25, EF-08-25, EP-02-25, EP- 04-25, EP-05-25, EP-06-25, EP-12-25, KF-01-25, KF-02-25, KF-03-25, KR-07-25, KR-09-25 and BodR-06-25) with high cellulose and amylolytic activity for the creation of decomposers.