Factors affecting bioleaching in the processing of non-metallics

Biotechnological treatment of non-metallics is based on bacterial leaching of raw material and dissolution of Fe. Bacterial iron dissolution ability is dependent on various physicochemical factors as temperature, acidity of solutions, redox potential, rapidity of water circulation and presence of organic sources. The Fe content in the quartz sands and feldspar samples by the biological leaching decreased as much as 60% and by subsequent using of electromagnetic separation of feldspars, the decrease of Fe content in 74% was achieved. However, the application of magnetic separation of quartz sands after bioleaching resulted in total iron removal of 93% and in such combined way prepared product contained 0.024 % of Fe2O3. Achieved results on iron removal point to the fact that combination of leaching and magnetic separation enables to obtain product usable in glass and ceramic industry.

Distribution characteristics of microplastics in the soil of mangrove restoration wetland and the effects of microplastics on soil characteristics

Microplastics that enter the soil environment are transformed by migration and can affect soil properties, which in turn have an impact on soil function and biodiversity. In this study, we investigated the distribution of soil microplastics at different planting densities and their effects on soil properties in a mangrove restoration wetland. The results showed that the average abundance of soil microplastics in the study area was 2177.5 n/500g, with the largest proportion of 0.038-0.05 mm diameter microplastics accounting for 70.9% and the rest of the diameter microplastics accounting for less than 20%, indicating that the smaller the diameter microplastics are easy to accumulate in the wetland soil. The abundance of microplastics in the restored area by planting density was ranked as 0.5×0.5m > 1.0×0.5m > 1.0×1.0m > control area. Three microplastics, polyethylene terephthalate (PET, accounted for 52%), polyethylene (PE, accounted for 24%), and polypropylene (PP, accounted for 15%), were the most prevalent and dominant microplastics in the soils of the area. SEM images showed that fractures, tears, EDS spectroscopy showed that a large number of metals were detected on the surface of microplastics. PET can influence the distribution of soil particle size due to its adsorptive viscosity, which may affect soil structure. Apart from soil pH, all other physicochemical factors changed significantly in response to PET. Besides, the results of the CV analysis reflect that soils in vegetated areas are more susceptible to the effects of PET than bare ground soils resulting in greater variability in the properties.

On the Development of New Forensic Tools for Detection of Human Skin Prints

The article reviews the main physical and physicochemical factors influencing the three-component system “fingerprint powder – prints bearing surface – sweat and grease print substance”. The authors propose new model compositions of fingerprint powders considering the reviewed common patterns: non-magnetic and luminescent magnetic. The features of prints bearing surfaces and developed fingerprint powders have been evaluated by applying electronic microscopy methods (scanning and probe microscopy). The authors have proven that the use of nano- and ultra disperse materials in the developed compositions (carbon nanotubes and shungite) enables to vary the sorption and adhesive capacity of fingerprint powders, which allows detecting fingerprints on varying surfaces with high selectivity toward the sweat and grease print substance and contrasting effect.

The Depth-Depended Fungal Diversity and Non-depth-Depended Aroma Profiles of Pit Mud for Strong-Flavor Baijiu

Microorganisms in pit mud are the essential factor determining the style of strong flavor Baijiu. The spatial distribution characteristics of fungal communities and aroma in the pit mud for strong flavor Baijiu from Xinjiang, China, were investigated using Illumina MiSeq high-throughput sequencing and electronic nose technology. A total of 138 fungal genera affiliated with 10 fungal phyla were identified from 27 pit mud samples; of these, Saccharomycopsis, Aspergillus, and Apiotrichum were the core fungal communities, and Aspergillus and Apiotrichum were the hubs that maintain the structural stability of fungal communities in pit mud. The fungal richness and diversity, as well as aroma of pit mud, showed no significant spatial heterogeneity, but divergences in pit mud at different depths were mainly in pH, total acid, and high abundance fungi. Moisture, NH4+, and lactate were the main physicochemical factors involved in the maintenance of fungal stability and quality in pit mud, whereas pH had only a weak effect on fungi in pit mud. In addition, the fungal communities of pit mud were not significantly associated with the aroma. The results of this study provide a foundation for exploring the functional microorganisms and dissecting the brewing mechanism of strong flavor Baijiu in Xinjiang, and also contributes to the improvement of pit mud quality by bioaugmentation and controlling environmental physicochemical factors.

Systems for Muscle Cell Differentiation: From Bioengineering to Future Food

In light of pressing issues, such as sustainability and climate change, future protein sources will increasingly turn from livestock to cell-based production and manufacturing activities. In the case of cell-based or cultured meat a relevant aspect would be the differentiation of muscle cells into mature muscle tissue, as well as how the microsystems that have been developed to date can be developed for larger-scale cultures. To delve into this aspect we review previous research that has been carried out on skeletal muscle tissue engineering and how various biological and physicochemical factors, mechanical and electrical stimuli, affect muscle cell differentiation on an experimental scale. Material aspects such as the different biomaterials used and 3D vs. 2D configurations in the context of muscle cell differentiation will also be discussed. Finally, the ability to translate these systems to more scalable bioreactor configurations and eventually bring them to a commercial scale will be touched upon.

A Sustainable Approach for the Production of Green Energy With the Holistic Treatment of Wastewater Through Microbial Electrochemical Technologies: A Review

With the plausible depletion of fossil fuels in the near future and its associated environmental impacts, researchers have instigated the search for eco-friendly renewable bioenergy. Moreover, the increase in water pollution by industrial and anthropogenic activities is another alarming global concern. In this regard, the production of renewable and sustainable green bioenergy utilizing wastewater through microbial electrochemical technologies (METs) can alleviate these crucial problems by providing a sustainable solution to meet both the demands of energy and fresh water supply. Moreover, different bio-centered techniques such as nitrification and denitrification for nitrogen removal, and elimination of carcinogenic metals, pathogens, and organic components utilizing microbiota followed by toxicity sensing of different pollutants have been efficaciously exhibited through METs. However, inferior bioenergy production and recovery of low biomass yield in METs with high operational cost are noteworthy bottlenecks that hinder the scalability of this technology. Therefore, this review elaborates different physicochemical factors affecting the performance of METs, microbial interaction for the development of stable biofilm and so forth. Moreover, a broad overview on the production of bioenergy, along with the removal of pollutants from wastewater through different types of METs are also highlighted. Furthermore, the production of biofuels like ethanol, methanol, biodiesel, and gaseous fuel like bio-H2 coupled with power generation using photosynthetic microorganisms via CO2 sequestration through METs are also discussed. Additionally, recent developments with future scope for the field-scale implementation of METs along with their bottlenecks have been discussed, which has not been critically reviewed to date.

Composition And Key-Influencing Factors of Bacterial Communities Active In Sulfur Cycling of Soda Lake Sediments

Bacteria are important participants in sulfur cycle of the extremely haloalkaline environment, e.g. soda lakes. The effects of physicochemical factors on the composition of sulfide-oxidizing bacteria (SOB) and sulfate-reducing bacteria (SRB) in soda lakes have remained elusive. Here, we surveyed the communities structure of total bacteria, SOB and SRB based on 16S rRNA, soxB and dsrB gene sequencing, respectively, in five soda lakes with different physicochemical factors. The results showed that the dominant bacteria in soda lakes sediments belonged to the phyla Proteobacteria, Bacteroidetes, Halanaerobiaeota, Firmicutes and Actinobacteria. SOB and SRB were widely distributed in lakes with different physicochemical characteristics，and the community composition were different . In general, salinity and inorganic nitrogen sources (NH4+-N, NO3--N) were the most significant factors. Specifically, the communities of SOB, mainly including Thioalkalivibrio, Burkholderia, Paracoccus, Bradyrhizobium, and Hydrogenophaga genera, were remarkably influenced by the levels of NH4+-N and salinity. Yet, for SRB communities, including Desulfurivibrio, Candidatus Electrothrix, Desulfonatronospira, Desulfonatronum, Desulfonatronovibrio, Desulfonatronobacter and so on, the most significant determinants were salinity and NO3--N. Besides, Rhodoplanes played a significant role in the interaction between SOB and SRB. From our results, the knowledge regarding the community structures of SOB and SRB in extremely haloalkaline environment was extended.