Rubber gloves biodegradation by a consortium, mixed culture and pure culture isolated from soil samples

Abstract An increasing production of natural rubber (NR) products has led to major challenges in waste management. In this study, the degradation of rubber latex gloves in a mineral salt medium (MSM) using a bacterial consortium, a mixed culture of the selected bacteria and a pure culture were studied. The highest 18% weight loss of the rubber gloves were detected after incubated with the mixed culture. The increased viable cell counts over incubation time indicated that cells used rubber gloves as sole carbon source leading to the degradation of the polymer. The growth behavior of NR-degrading bacteria on the latex gloves surface was investigated using the scanning electron microscope (SEM). The occurrence of the aldehyde groups in the degradation products was observed by Fourier Transform Infrared Spectroscopy analysis. Rhodococcus pyridinivorans strain F5 gave the highest weight loss of rubber gloves among the isolated strain and posses latex clearing protein encoded by lcp gene. The mixed culture of the selected strains showed the potential in degrading rubber within 30 days and is considered to be used efficiently for rubber product degradation. This is the first report to demonstrate a strong ability to degrade rubber by Rhodococcus pyridinivorans.

Evaluation of the genotoxic activity and acute toxicity of Euphorbia splendens latex, a molluscicide for the control of Schistosomiasis

The latex of euphorbia splendens var. hislopii has a molluscicidal action at low concentration (LD90 less than 1.5 ppm or 1.5 */ml) against the vector snails of schistosomiasis. In the present study, the latex in natura or after lyophilization was submitted to the Ames test and the chromotest to evaluate genotoxicity, to the Microtox System to determine acute toxicity, and to the Chinese hamster ovary cell assay (CHO) to measure cytotoxicity. The latex had no mutagenic activity in the presence or absence of S9 toward the TA98 and TA100 strains of Salmonella typhimurium (Ames test) at concentration up to 200 */plate (in natura) and of 200 *g/plate (lyophilized). The lyophilized latex had no genotoxic activity (Chromotest) and acute toxic effect on Photobacterium phosphoreum at concentrations up to 445 *g/ml, whereas the sample in natura had a toxic effect with an EC50 of 148,000 *l/l (or ppm). In the CHO/cytotoxicity assay, the lyophilized latex had no cytotoxicit effect in quantities up to 200 *g. The latex was found to have no acute toxicity or mutagenic at the concentrations of 10 to 12 *g/ml (or ppm) that are being proposed for molluscicidal use in the field