Mineralization of dimethylsilanediol by microorganisms isolated from soil

Abstract

Abstract-Previous studies have shown that polydimethylsiloxane is hydrolyzed

Ecotoxicity and biodegradability in soil and aqueous media of lubricants used in forestry applications

“…The aim of this study was therefore to measure biodegradability data that may be reproduced whatever the soil and comparable to the results shown in Table 2, obtained in accordance with the OECD 301B method. Results showed that biodegradation in a liquid medium was more rapid and complete than in a soil environment (Chaineau et al, 1999;Sabourin et al, 1999) and confirm the hypotheses of the better availability of the substrate in a liquid medium than in a soil environment and a better oxygenation of the liquid medium facilitating the aerobic biodegradation process. Nature and origin of inocula have also a great influence on results of biodegradation (Mezzanote et al, 2005) could be an handicap for the use of this kind of test in liquid medium with different activated sludge inocula.…”

Organosilicon Materials

“…Methylsilanols are expected to degrade photolytically in the atmosphere and in water to silica and carbon dioxide [82][83][84]. Dimethylsilanediol has also been recently shown to biodegrade to methylsilanetriol, carbon dioxide, and silica [78,90,100].…”

“…Sabourin et al [90] added 100 ppm 14C-dimethylsilanediol to four soils. All four soils produced 14C0 2 .…”

“…The kinetic order is not known, and in units of ppm wk-1 , the rates in Sabourin et al Isolation of Active Organisms. Since extensive previous attempts at finding microorganisms that could utilize dimethylsilanediol as a primary carbon source had failed, Sabourin et al [90] sought to isolate soil organisms that could co-metabolize dimethylsilanediol, while growing on another compound as a source of carbon and energy. A number of primary carbon sources were chosen because of their structural analogy to dimethylsilanediol, or because they provided methyl groups in compounds that are widely utilizable by methylotrophs, or because they provided a rich medium for diverse communities.…”

“…Hydroxylation of a methyl group of dimethylsilanediol followed by oxidation to an aldehyde or carboxylic acid function would yield a spontaneous elimination of formaldehyde or 14C0 2 • The labeled formaldehyde would be readily oxidized to 14C0 2 or available as a carbon source for many organisms. In a later work, Sabourin et al [100] described the identification of both methylsilanetriol and inorganic silicate as products of dimethylsilanediol degradation by the purified cultures in liquid medium. Thus, the biodegradation and photolytic pathways are both oxidative demethylations, which lead to sequential formation of silanol functions to replace the methyl groups, and ultimately to mineralization.…”