Novel s-triazine-degrading bacteria isolated from agricultural soils of central Chile for herbicide bioremediation

s-Triazine-degrading bacterial strains were isolated from long-term simazine-treated agricultural soils of central Chile. The number of culturable heterotrophic bacteria of these agricultural soils (7 x 10(6) CFU/g of dry soil) was not affected by simazine application on field. The simazine-degrading bacterial strains P51, P52 and C53 were isolated by enrichment in minimal medium using simazine as the sole nitrogen source. Resting cells of strains P51 and P52 degraded >80 percent of simazine within 48 hrs, whereas strain C53 was able to remove >60 percent of the herbicide. The atzA and atzD genes of the s-triazine upper and lower catabolic pathways were detected in strains P51 and C53, while only atzD gene was observed in strain P52. To compare the bacterial 16S rRNA gene sequence structure, ARDRA were performed using the restriction enzymes Msp1 and Hha1. ARDRA indicated that strain P52 was a different ribotype than C53 and P51 strains. For further characterization the novel isolates were identified by 16S rRNA gene sequencing. Strains C53 and P51 belong to the genus Stenotrophomonas and the strain P52 belongs to the genus Arthrobacter . s -Triazine-degrading bacterial strains isolated from contaminated soils could be used as biocatalysts for bioremediation of these herbicides.

[Effect of the herbicide Herbazin-50 (simazine) on the wound process in animals]. / Vliianie na kherbitsida kherbazin-50 (simazin) vurkhu raneviia protses pri zhivotnite.

Herbazin 50 was used as an experimental model to record species differences in the process of wound healing in horses, cattle, and sheep. It was established that the local and oral application of this herbicide inhibited wound healing, and this effect was more strongly manifested in the phase of hydratation. There were clearly expressed species-associated variations: in horses the elimination of the irritant was achieved through a severe inflammation response of a purulent character, while in cattle the rapid response of the connective tissue was leading, with concurrent premature maturation. Changes set in under the effect of the herbicide, consisting in the alkalinization of the wound exudate, which led to changes in the wound microflora.

[Effect of herbazin 50 on the course of suppurative surgical infection in sheep]. / Vliianie na kherbazin 50 vurkhu protichaneto na gnoina khirurgicheska infektsiia pri ovtsete.

Twelve sheep, divided into two groups of 6 animals each, were used. The first (test) group was offered herbazin -50 with the feed in the course of 90 days after which the animals were infected via the joints with Corynebacterium pyogenes. The second (control) group was also infected with the same pathogen in the same way. During the time the preparation was given and 30 days post infection the animals were kept under observation, following up their clinical, condition, and the occasional morphological and biochemical changes taking place in the blood and the immunobiologic responsiveness. It was found that sheep treated with herbazin -50 with a following infection with Corynebacterium pyogenes raised their blood levels of sugar, total protein, potassium, sodium, magnesium, SGOT, SGPT, and manifested an increased ESR, and lower calcium, inorganic phosphorus, carotene, vitamin A, and cholesterine serum level. It was also established that surgical infections brought about through such introduction of C. pyogenes developed much more rapidly and ran a much more severe course in sheep after the preliminary treatment with herbazin -50. It is believed that they emerged after suppressing the immunologic responsiveness with the use of the preparation.