Marine bacteria mediated degradation of nylon 66 and 6

Marine bacteria (Bacillus cereus, Bacillus sphericus, Vibrio furnisii, and Brevundimonas vesicularis) were shown to degrade nylon 6 and 66 in mineral salt medium at 35 °C and pH of 7.5 under submerged enrichment conditions with the polymer as the sole carbon source. The degradation led to the formation of new functional groups NHCHO, CH3, CONH2, CHO and COOH. Maximum degradation was observed with Bacillus cereus for both the nylons. Average molecular weight decreased by 42% and 31% and weight decreased by 7% and 2% in the case of nylon 66 and nylon 6, respectively, over a period of three months. Differential scanning calorimetry showed a reduction in melting temperature (∼ of 1 °C) and enthalpies of fusion indicating decrease in crystallinity. Epi-fluorescent microscope of the degraded samples showed surface stripping and groves. The extent of degradation observed with the marine organisms was better than soil organisms reported in the literature.