RESUMO
Salinity is the most important factor for the growth of crops. It is an effective method to alleviate the toxic effect caused by salt stress using saline-alkali-tolerant and growth-promoting bacteria in agriculture. Seven salt-tolerant bacteria were screened from saline-alkali soil, and the abilities of EPS production, alkalinity reduction and IAA production of the selected strains were investigated. A dominant strain DB01 was evaluated. The abilities of EPS production, alkalinity reduction and IAA production of strain DB01 were 0.21 g/g, 8.7% and 8.97 mg/L, respectively. The isolate was identified as Halomonas aquamarina by partial sequencing analysis of its 16S rRNA genes, and had the ability to inhibit the growth of Fusarium oxysporum f. sp., Alternaria solani, Phytophthora sojae and Rhizoctonia cerealis. It also could promote root length and germination rate of wheat seedlings under salt stress. Halomonas aquamarina can provide theoretical basis for the development of soil microbial resources and the application in saline-alkali soil improvement.
Assuntos
Álcalis , Metabolismo , Bactérias , Genética , Halomonas , Genética , Raízes de Plantas , Microbiologia , RNA Ribossômico 16S , Genética , Tolerância ao Sal , Genética , Plântula , Microbiologia , Solo , Química , Microbiologia do Solo , Triticum , MicrobiologiaRESUMO
Glutathione (GSH) plays an important role in the responses of microorganisms to the environmental stimulation and stress. The effect of H2O2 stress under different fermentation time and H2O2 concentration as well as continuous stress on GSH fermentation of Candida utilis were investigated in this paper. It was found that low concentration of H202 accelerated GSH production. When treated by low concentration of H2O2 (36 mmol/L), the final concentration of GSH reached 922 mg/L and the intracellular GSH content reached 1.64%, which increased by 7% and 35% than the controls, respectively.
