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A bacterial strain named CB4, with highly effective glyphosate degradation capability, was isolated from soil after enrichment. On the basis of the Biolog omniLog identification system (Biolog) and 16S ribosomal RNA (rRNA) gene sequencing methods, strain CB4 was identified as Bacillus cereus. Further experiments were carried out to optimize the growth of strain CB4 and the glyphosate degradation activity by high performance liquid chromatography (HPLC). The optimal conditions were found as follows: initial pH 6.0, incubation temperature 35°C, glyphosate concentration 6 g L(-1), inoculation amount 5% and incubation time 5 days. Under the optimal conditions, stain CB4 utilized 94.47% of glyphosate. This is the first report on B. cereus with a capacity to utilize herbicide glyphosate, and it can degrade glyphosate concentrations up to 12 g L(-1). Metabolization of glyphosate by strain B. cereus CB4 was studied. Results indicated that two concurrent pathways were capable of degrading glyphosate to AMPA, glyoxylate, sarcosine, glycine and formaldehyde as products. Glyphosate breakdown in B. cereus CB4 was achieved by the C-P lyase activity and the glyphosate oxidoreductase activity.

A series of 1-ethyl-6-fluoro-1,4-dihydro-4-oxo-7(1-piperazinyl)quinoline-3-carboxylic acid (norfloxacin) derivatives were prepared according to the principle of combinating bioactive substructures and tested for their activities against five plant pathogenic bacteria and three fungi in vitro. The preliminary bioassays indicated that almost all synthesized target compounds retained the antibacterial activities of norfloxacin and had some antifungal activities as carboxylic acid amide compounds. The activities of compounds 1 and 22 against Xanthomonas oryzae were better than norfloxacin and all tested compounds had better antibacterial activities as compared to the agricultural streptomycin sulfate (a commercial bactericide) against X. oryzae, Xanthomonas axonopodis and Erwinia aroideae. Additionally, compounds 2 and 20 displayed good antifungal activities against Rhizoctonia solani and their inhibition of growth reached 83% and 94% respectively at the concentration of 200 mg/L.