ABSTRACT
Phytoremediation can help remediate potential toxic elements (PTE) in soil. Microorganisms and soil amendments are effective means to improve the efficiency of phytoremediation. This study selected three microorganisms that may promote phytoremediation, including bacteria (Ceratobasidium), fungi (Pseudomonas mendocina), and arbuscular-mycorrhizal fungi (AMF, Funneliformis caledonium). The effects of single or mixed inoculation of three microorganisms on the phytoremediation efficiency of Paspalum vaginatum and Pennisetum alopecuroides were tested under three different degrees of cadmium-contaminated soil (low 10 mg/kg, medium 50 mg/kg, and high 100 mg/kg). The results showed that single inoculation of AMF or Pseudomonas mendocina could significantly increase the biomass of two plants under three different degrees of cadmium-contaminated soil, and the growth-promoting effect of AMF was better than Pseudomonas mendocina. However, simultaneous inoculation of these two microorganisms did not show a better effect than the inoculation of one. Inoculation of Ceratobasidium reduced the biomass of the two plants under high concentrations of cadmium-contaminated soil. Among all treatments, the remediation ability of the two plants was the strongest when inoculated with AMF alone. On this basis, this study explored the effect of AMF combined with corn-straw-biochar on the phytoremediation efficiency of Paspalum vaginatum and Pennisetum alopecuroides. The results showed that biochar could affect plant biomass and Cd concentration in plants by reducing Cd concentration in soil. The combined use of biochar and AMF increased the biomass of Paspalum vaginatum by 8.9-48.6% and the biomass of Pennisetum alopecuroides by 8.04-32.92%. Compared with the single use of AMF or biochar, the combination of the two is better, which greatly improves the efficiency of phytoremediation.
ABSTRACT
Moringa is multipurpose promising tree particularly for medicinal use. With its high nutritive and pharmaceutical values, every part of the tree is suitable for human consumptions. The use of vegetate parts, seeds or extracts requires toxicological evaluations to prove and verify safety uses before being added to pharmaceutical medicine, or any other products related to human diet. In this study, Moringa peregrina seeds, grown in high elevation mountain in Saint Catherin area, were investigated and evaluated for their toxicity with respect to its topological potential through histological and biochemical studies in Albino rats. Daily doses of 0, 500, 1000 and 2000 mg/kg body weight of dry seed of M. peregrina were administered orally to 4 groups of rats for 14 days. Biochemical and histopathological results were evaluated by standard methods. Measured biochemical parameters, insulin, albumin, total protein, creatinine, urea, uric acid, Follicle-stimulating hormone, Luteinizing hormone and Testosterone, revealed normal levels compared to control group. However, measured level of blood sugars, cholesterol, triglyceride and liver enzyme, displayed significant decreases. No histopathological changes were detected in the body tested organs. In consequences, intake of different doses of M. peregrina, even high one, exhibit no organ toxicity and are safe for human use.
