Plastic degradation by biological systems with re-utilization of the by-products could be a future solution to the global threat of plastic waste accumulation. Here, we report that the saliva of Galleria mellonella larvae (wax worms) is capable of oxidizing and depolymerizing polyethylene (PE), one of the most produced and sturdy polyolefin-derived plastics. This effect is achieved after a few hours’ exposure at room temperature under physiological conditions (neutral pH). The wax worm saliva can overcome the bottleneck step in PE biodegradation, namely the initial oxidation step. Within the saliva, we identify two enzymes, belonging to the phenol oxidase family, that can reproduce the same effect. To the best of our knowledge, these enzymes are the first animal enzymes with this capability, opening the way to potential solutions for plastic waste management through bio-recycling/up-cycling.

On treatment of a bentonite from La Serrata-Sierra de Nijar, Spain, with HC1 of increasing concentration (1-8 N), an evolution in the hysteresis loops of the corresponding N2 adsorption-desorption isotherms is revealed. In the first stages of the attack, an opening of the bentonite lamellae is produced by abstraction of interlayered cations and corresponding water molecules. Thus, an accessibility, otherwise impossible, of nitrogen to the internal surface of the samples with subsequent increase in N2 adsorption occurs. A second stage is produced when the octahedral aluminum sheet is dissolved as the acid attack progresses.In both stages H3 loops as well as pore ranges are preserved. At higher HC1 concentrations, the partial destruction of the tetrahedral sheet and the texture of the resulting amorphous free silica, together with the random occlusion of the unaltered montmorillonitic interlamellar spaces, result in changes of texture, slit-shaped pores becoming ink-bottle pores and H3-type hysteresis changing to the H2 type. Pore size increases and total pore volume decreases. Specific surface areas grow from 61 m2 g"1 for the natural sample to 345 m2 g"1 for the 8 N HC1 treated sample, passing through a maximum of 416 m2 g"1 for the 4 N HC1 treated specimen, depending on which of the effects described above predominates. Cientifica y Tecnica for financial support of this work under Projects 83051 and 678/553, respectively.

The aim of the study was to investigate the distribution of 163 A/G osteoprotegerin gene promoter and 1181 G/C osteoprotegerin exon 1 polymorphisms in a group of women with different hormonal status and to analyze their relationship with BMD. Osteoprotegerin polymorphisms and BMD were analyzed in 332 women (69 premenopausal and 263 postmenopausal). BMD was quantified at the lumbar spine (L 2-4), femoral neck, and total hip. Genotyping for the presence of different polymorphisms was performed using the Custom Taqman ((R)) SNP Genotyping assays. There were not significant differences in BMD according to 163 A/G genotype. However, significant differences in lumbar spine BMD were found according to 1181 G/C alleles. Thus, women with CC genotype had significant higher BMD at the lumbar spine than those with GC or GG genotype. No differences were found in femoral neck and total hip BMD. In age-adjusted models, the 1181 G/C OPG polymorphism explained 2.2% of BMD variance at the spine, 0.3% at the femoral neck, and 0.9% at the total hip in the whole group. In the subgroup of premenopausal women, the polymorphism was strongly related to spine BMD, and explained 11.5% of the variance, whereas body weight explained 7.9%. The 1181 G/C polymorphism was associated with lumbar spine BMD in Spanish women. Premenopausal women with the CC genotype had a higher BMD.

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