Acrylonitrile induces autolysis Bacillus subtilis

The impact of acrylonitrile and bioaugmentation on the biodegradation activity and bacterial community structure of a topsoil

The analysis of the bacterial community within the soil using DGGE showed acrylonitrile (ACN) could lead to the selection of significantly similar communities. Moreover, Rhodococcus sp. AJ270 was successfully established in the soil community. High GC G+-bacteria also responded positively to ACN addition. Bioaugmentation or carbon addition had no impact on the rate or degree of ACN degradation. ACN could be readily degraded by the soil bacteria, however, the community structure was significantly affected by its addition as well as by the addition of carbon or Rhodococcus sp. AJ270. The bioaugmentation of the soil with this strain was successful, in that the organism became established within the community. ACN addition to a soil produces statistically significant changes in the bacterial community.

Biological degradation of cyanide compounds

Cyanide compounds are produced as waste products of a number of industrial processes and several routes for their removal from the environment are under investigation, including the use of biodegradation. The most recent developments in this area have come from studies of the hydrolytic and oxidative pathways for biodegradation and the conditions that affect their activity. The biodegradation of cyanide under anaerobic conditions has also recently demonstrated the feasibility for concomitant biogas generation, a possible economic benefit of the process. Significant advances have been reported in the use of plants for the phytoremediation of cyanide compounds and evidence for the biodegradation of thiocyanate and metal-cyanide complexes has become available. Despite these advances, however, physical and economic factors still limit the application of cyanide biodegradation, as do competing technologies.

Stimulation of microbial autolytic system by tryptic casein hydrolysate

Antimicrobial activity of a tryptic casein hydrolysate (TCH), its mode of antimicrobial action and its efficacy in treatment using a newborn calf colibacillosis model are described. The antimicrobial activity of TCH activated the autolytic system of the microbial cell and was expressed mathematically as the autolysis activation index. TCH stimulated the autolytic enzyme system of the 19 bacterial and five fungal strains tested. The autolysis activation index for naturally-autolyzing microorganisms was 1.45-22.0. Autolysis in three bacterial and one fungal strain that did not lyse in the absence of TCH was increased in its presence by 3.9-56.7% showing activation of latent autolysis. The in vivo trials on 800 newborn calves revealed 93.0% therapeutic and 93.5% prophylactic efficacy for TCH. These levels were similar to the 95.0 and 95.5% attained when Fermosorb, an authorized antimicrobial drug, was used.