tailieunhanh - Innovations in Biotechnology Part 10

Tham khảo tài liệu 'innovations in biotechnology part 10', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Exogenous Catalase Gene Expression as a Tool for Enhancing Metabolic Activity and Production of Biomaterials in Host Microorganisms 261 lower compared with the other genera tested the growth of almost all of rhizobia tested was severely repressed even in the presence of mM H2O2. However the vktA-transformant showed almost the same cell density as the parent in the presence of 10 mM H2O2 even with 50 mM H2O2 the vktA-transformant could grow and the cell density reached levels half that of the parent at 24 h then almost the same as the parent at 30 h after incubation. These results indicate that the vktA-transformant acquired resistance against H2O2 through the enhancement of catalase production in the cells. ARA1 Cultivation - . . Strain condition Nodule number Nodule weight _ _ . . permgdrv . per plant per dry wt per plant wt of nodule Per p ant Seed bag Parent vktA -transformant 129 111 82 2 I21 Pot Parent vktA -transformant 75 89 16 6 0 7 01- l2 12 1 Acetylene reduction activity pmol of C2H2 h . 2 Significant differences were evaluated by Student s t test P . Table 1. Number weight and acetylene reduction activity ARA of nodules formed in the combination of Phaseolus vulgaris L. cv. Yukitebou and vktA-transformed R. leguminosarum. Values were obtained from 20 determinants of at least two independent experiments. The values given are the means S. D. of 20 different tests. Adapted with permission from Orikasa et al. 2010 . The host plant Phaseolus vulgaris L. was inoculated with vktA-transformed R. leguminosarum cells 106 cells per seed and after cultivation in a seed bag with Norris and Date medium Dye 1980 or in a pot filled with vermiculite the number weight and nitrogenase activity acetylene reduction activity ARA of the nodules were measured Table 1 . For the seed bag the number and weight of nodules did not show a .