ABSTRACT
AIM: To explore whether ultraviolet (UV) light treatment within a closed circulating and filtered water drainage system can kill plant pathogenic species. METHODS AND RESULTS: Ultraviolet experiments at 254 nm were conducted to determine the inactivation coefficients for seven plant pathogenic species. At 200 mJ cm(-2), the individual species log reductions obtained for six Ascomycete fungi and a cereal virus were as follows: Leptosphaeria maculans (9·9-log), Leptosphaeria biglobosa (7·1-log), Barley stripe mosaic virus (BSMV) (4·1-log), Mycosphaerella graminicola (2·9-log), Fusarium culmorum (1·2-log), Fusarium graminearum (0·6-log) and Magnaporthe oryzae (0·3-log). Dilution experiments showed that BSMV was rendered noninfectious when diluted to >1/512. Follow-up large-scale experiments using up to 400 l of microbiologically contaminated waste water revealed that the filtration of drainage water followed by UV treatment could successfully be used to inactivate several plant pathogens. CONCLUSIONS: By combining sedimentation, filtration and UV irradiation within a closed system, plant pathogens can be successfully removed from collected drainage water. SIGNIFICANCE AND IMPACT OF THE STUDY: Ultraviolet irradiation is a relatively low cost, energy efficient and labour nonintensive method to decontaminate water arising from a suite of higher biological containment level laboratories and plant growth rooms where genetically modified and/or quarantine fungal and viral plant pathogenic organisms are being used for research purposes.
Subject(s)
Agriculture/methods , Ascomycota/radiation effects , RNA Viruses/radiation effects , Ultraviolet Rays , Water Microbiology , Water Purification/methods , Decontamination , Filtration , Microscopy, Electron, Transmission , Plants/virology , RNA Viruses/ultrastructure , Virus Inactivation/radiation effectsABSTRACT
Two studies are given in this paper. Both studies use a combined gamma sensing and global positioning system to monitor land contaminated with gamma emitting radioisotopes. The first is the 3D profiling a large (100m x 200m x 15m) tip of the residue from radium extraction processing. The second is the dynamic monitoring of beaches to locate and recover small particles of radioactive material.