Al Disi, Z.A., Bontognali, T.R.R., Jaoua, S., Attia, E., Al-Kuwari, H.A.S., Zouari, N., 2019. Influence of 2+ 2+ temperature, salinity and Mg :Ca ratio on microbially-mediated formation of Mg-rich carbonates by Virgibacillus strains isolated from a sabkha environment. Scientific Reports 9, 19633.

https://doi.org/10.1038/s41598-019-56144-0 2+ Studies have demonstrated that microbes facilitate the incorporation of Mg into carbonate minerals, leading to the formation of potential dolomite precursors. Most microbes that are capable of mediating Mg-rich carbonates have been isolated from evaporitic environments in which temperature and salinity are higher than those of average marine environments. However, how such physicochemical factors affect and concur with microbial activity influencing mineral precipitation remains poorly constrained. Here, we report the results of laboratory Virgibacillus precipitation experiments using two mineral-forming strains and one non-mineral-forming strain Bacillus licheniformis of , all isolated from the Dohat Faishakh sabkha in Qatar. They were grown under 2+ 2+ different combinations of temperature (20°, 30°, 40 °C), salinity (3.5, 7.5, 10 NaCl %w/v), and Mg :Ca ratios 2+ (1:1, 6:1 and 12:1). Our results show that the incorporation of Mg into the carbonate minerals is significantly 2+ 2+ affected by all of the three tested factors. With a Mg :Ca ratio of 1, no Mg-rich carbonates formed during the 2+ 2+ experiments. With a Mg :Ca ratios of 6 and 12, multivariate analysis indicates that temperature has the 2+ 2+ highest impact followed by salinity and Mg :Ca ratio. The outcome of this study suggests that warm and saline environments are particularly favourable for microbially mediated formation of Mg-rich carbonates and provides new insight for interpreting ancient dolomite formations.

Alexandrov, G.A., Brovkin, V.A., Kleinen, T., Yu, Z., 2020. The capacity of northern peatlands for long-term carbon sequestration. Biogeosciences 17, 47-54.

https://www.biogeosciences.net/17/47/2020/ Northern peatlands have been a persistent natural carbon sink since the Last Glacial Maximum. The continued growth and expansion of these carbon-rich ecosystems could offset a large portion of anthropogenic carbon emissions before the end of the present interglacial period. Here we used an impeded drainage model and gridded data on the depth to bedrock and the fraction of histosol-type soils to evaluate the limits to the growth of northern peatland carbon stocks. Our results show that the potential carbon stock in northern peatlands could reach a total of 875±125 Pg C before the end of the present interglacial, which could, as a result, remove 330±200 Pg C of carbon from the atmosphere. We argue that northern peatlands, together with the oceans, will potentially play an important role in reducing the atmospheric carbon dioxide concentration over the next 5000 years.

Ali, N., Zhang, Q., Liu, Z.-Y., Li, F.-L., Lu, M., Fang, X.-C., 2020. Emerging technologies for the pretreatment of lignocellulosic materials for bio-based products. Applied Microbiology and Biotechnology 104, 455-473.

https://doi.org/10.1007/s00253-019-10158-w Exploring a cheap and clean renewable energy has become a common destination round the world with the depletion of oil resources and the concerns of increasing energy demands. Lignocellulosic biomass is the most abundant renewable resource in the biosphere, and the total biomass formed by plant photosynthesis reached more than 200 billion tons every year. Cellulase and hemicellulose and lignin degradation enzymes, the efficient biocatalyst, could efficiently convert the lignocellulosic biomass into sugars that could be further processed into biofuels, biochemical, and biomaterial for human requirement. The utilization and conversion of cellulosic biomass has great significance to solve the problems such as environmental pollution and energy crisis. Lignocellulosic materials are widely considered as important sources to produce sugar streams that can be fermented into ethanol and other organic chemicals. Pretreatment is a necessary step to overcome its intrinsic recalcitrant nature prior to the production of important biomaterial that has been investigated for nearly 200 years. Emerging research has focused in order of economical, eco-friendly, and time-effective solutions, for large-scale operational approach. These new mentioned technologies are promising for lignocellulosic biomass degradation in a huge scale biorefinery. This review article has briefly explained the emerging technologies