http://www.sciencedirect.com/science/article/pii/S1367593119301504 Expanding the repertoire of reactions available to enzymes is an enduring challenge in biocatalysis. Owing to the synthetic versatility of transition metals, metalloenzymes have been favored targets for achieving new catalytic functions. Although less well explored, enzymes lacking metal centers can also be effective catalysts for non-natural reactions, providing access to reaction modalities that compliment those available to metals. By understanding how these activation modes can reveal new functions, strategies can be developed to access novel biocatalytic reactions. This review will cover discoveries in the last two years which access catalytic reactions that go beyond the native repertoire of metal-free biocatalysts.

Sañé, E., Ingrassia, M., Martorelli, E., Chiocci, F.L., 2020. Amino acids in surface sediments of the Zannone Island shelf (Western Mediterranean Sea): Possible bioindicators of submarine hydrothermal activity. Organic Geochemistry 140, 103960.

http://www.sciencedirect.com/science/article/pii/S0146638019301974 This study shows results from amino acid analysis of seafloor sediment sampled between ~80 and ~130 m depth, within an active hydrothermal field located off Zannone Island (Tyrrhenian Sea). The total hydrolysable amino acid (THAA) content was determined at eight stations, three located within the main hydrothermal depression (i.e. the Zannone Giant Pockmark, ZGP) and five located in the surrounding seafloor. THAA - 1 concentration ranged between ~2 and ~11 nmol mg dw and the lowest THAA concentrations were found at stations located within the ZGP. Amino acids resistant to degradation or originating from bacteria (β -alanine, histidine, leucine, arginine and lysine) had higher relative abundances inside the ZGP, whereas amino acids susceptible to degradation or originating from cellular plasma (proline, phenylalanine and tyrosine) showed higher relative abundances outside the ZGP. Degradation and reactivity indices were calculated, and the sedimentary organic matter in the three outside ZGP stations B07, B08 and B09 was found to be the most labile and reactive. Together with THAA concentrations, sediment grain size and carbon percentages were measured at 12 stations, five located within the ZGP and seven located outside the ZGP. At all stations, the percentage of sand was ~75% or higher. Carbon percentages were lower in samples located inside the ZGP than in the surrounding stations. The southern outside ZGP station B12 was found to be similar in terms of amino acids composition to the three inside ZGP stations, suggesting the influence of the hydrothermal fluids at this station.

Sankaran, R., Parra Cruz, R.A., Pakalapati, H., Show, P.L., Ling, T.C., Chen, W.-H., Tao, Y., 2020. Recent advances in the pretreatment of microalgal and lignocellulosic biomass: A comprehensive review. Bioresource Technology 298, 122476.

http://www.sciencedirect.com/science/article/pii/S0960852419317067 Microalgal and lignocellulosic biomass is the most sumptuous renewable bioresource raw material existing on earth. Recently, the bioconversion of biomass into biofuels have received significant attention replacing fossil fuels. Pretreatment of biomass is a critical process in the conversion due to the nature and structure of the biomass cell wall that is complex. Although green technologies for biofuel production are advancing, the productivity and yield from these techniques are low. Over the past years, various pretreatment techniques have been developed and successfully employed to improve the technology. This paper presents an in-depth review of the recent advancement of pretreatment methods focusing on microalgal and lignocellulosic biomass. The technological approaches involving physical, chemical, biological and other latest pretreatment methods are reviewed.

Santana, A., Comas, A., Wise, S., Wilson, W.B., Campiglia, A.D., 2020. Instrumental improvements for the trace analysis of structural isomers of polycyclic aromatic hydrocarbons with molecular mass 302 Da. Analytica Chimica Acta 1100, 163-173.

http://www.sciencedirect.com/science/article/pii/S0003267019313078