Genome Annotation of Poly(lactic acid) Degrading Pseudomonas aeruginosa,Sphingobacterium sp. and Geobacillus sp.

Pseudomonas aeruginosa and Sphingobacterium sp. are well known for their ability to decontaminate many environmental pollutants while Geobacillus sp. have been exploited for their thermostable enzymes. This study reports the annotation of genomes of P. aeruginosa S3, Sphingobacterium S2 and Geobacillus EC-3 that were isolated from compost, based on their ability to degrade poly(lactic acid), PLA. Draft genomes of the strains were assembled from Illumina reads, annotated and viewed with the aim of gaining insight into the genetic elements involved in degradation of PLA. The draft genome of Sphinogobacterium strain S2 (435 contigs) was estimated at 5,604,691 bp and the draft genome of P. aeruginosa strain S3 (303 contigs) was estimated at 6,631,638 bp. The draft genome of the thermophile Geobacillus strain EC-3 (111 contigs) was estimated at 3,397,712 bp. A total of 5385 (60% with annotation), 6437 (80% with annotation) and 3790 (74% with annotation) protein-coding genes were predicted for strains S2, S3 and EC-3, respectively. Catabolic genes for the biodegradation of xenobiotics, aromatic compounds and lactic acid as well as the genes attributable to the establishment and regulation of biofilm were identified in all three draft genomes. Our results reveal essential genetic elements that facilitate PLA metabolism at mesophilic and thermophilic temperatures in these three isolates.     

Dependence of magnetoelectric properties on the magnetostrictive content in 0–3 composites

The magnetoelectric response in composites of barium titanate (BTO) and cobalt ferrite (CFO) has been determined by measuring the magnetoelectric susceptibility coefficient. This was done by two different methods: magnetocapacitance measurements and magnetoelectric voltage measurement using a lock-in technique. These composites were prepared by the sol–gel method. Four different compositions with different molar ratios of the magnetostrictive phase (CFO) embedded in a piezoelectric matrix of BTO were studied to investigate the effect of the magnetostrictive content and the number density of interfaces on the magnetoelectric response. It was found from both techniques that the magnetoelectric coupling effect increases with the increase of applied field and it had a non-linear dependence on the percentage of magnetostrictive content in the composites.     

Biotechnological recycling of critical metals from waste printed circuit boards

Critical metals are key raw materials for new generation clean energy production. The extraction of critical metals often follows the difficult processing of primary ores and they are many times recovered as the companion metals. With the depletion of primary reserves, the focus has now shifted to processing the urban mines, like electronic (e-)waste. Among the different types of e-waste, the waste printed circuit boards (WPCBs) are the major reservoir of high-value critical metals and are usually treated by the traditional pyro- and/or hydro-metallurgical techniques. However, the application of microbial activities in metals recycling is rapidly emerging as a green technology in comparison to smelter or chemical processing. The application of microorganisms (bacteria/fungi) in WPCBs’ recycling is being increasingly explored in order to meet the parallel objectives of resource recovery and pollution mitigation. Therefore, the present article assesses the current frontiers in bioleaching of critical metals from WPCBs and contains discussions on process fundamentals, challenges, and perspectives. The applicability of microbial recycling of WPCBs at a higher scale in terms of a circular economy and urban mining notion, the techno-economic analysis, and environmental sustainability in comparison to the chemical processing route are also discussed. © 2020 Society of Chemical Industry     

Reverse logistics optimization of an industrial air conditioner manufacturing company for designing sustainable supply chain: a fuzzy hybrid multi-criteria decision-making approach

Wireless Networks - Magnified resource consumption and depletion of natural resources calls for non-flexible or strict regulations and penalties on industrial operations, increased rate of...     

Integration of microbial and chemical processing for a sustainable metallurgy

Bioprocessing for the recovery of metal from divergent resources using the microbial strategy has emerged as a green technology in metallurgical operations. The limitations to maintain the ideal condition for bacterial growth with slow kinetics, however, have been considered as major obstacles to bioprocessing being implemented more widely. This can be overcome by integrating the microbes with a chemical processing route. The available reports on recent developments in hybrid bio‐chemical processing of both primary and secondary resources have presented promising results, exhibiting the potential for use in large‐scale metallurgy. In this context, reviewing the factors of the hybrid process would benefit from knowledge acquired in fundamental studies. The present review focuses on bio‐chemical process integration using eco‐friendly design tools for treating the difficult to extract resources and complex spent materials as well. Furthermore, the potential of hybrid technology has been evaluated by establishing an economic model as a case study which encompasses features of economic development, environmental consideration and societal matters to achieve process sustainability. © 2017 Society of Chemical Industry     

黑曲霉菌一步浸取低砷硫化矿:Taguchi正交优化(英文)

A study was carried out to examine the possibility for Aspergillus niger strain KBS4 to bioleach metals from sulphide ore with low concentration of arsenic and to optimize the parameters that affect this process by orthogonal array optimization. Fungal sample was collected, purified and sequenced. The bioleaching process was optimized with L25 Taguchi orthogonal experimental array design. Five factors were investigated and 25 batch bioleaching tests were run at five levels for each factor. The parameters were initial pH, particle size, pulp density, initial inoculums and residence time for bioleaching. The experimental results showed that under optimized leaching conditions: pH 5.5, particle size 180 μm, initial inoculums size 3×10 7 spores per ml, pulp density 15% and residence time of 20 days, the bioleach ability of metals were 63% Fe, 68% Zn, 60% As, 79% Cu and 54% Al. The biosorption of metal ions by fungal biomass might occur during the bioleaching process but it did not hinder the removal of metal ions by bioleaching.     

Bmi1 Augments Proliferation and Survival of Cortical Bone-Derived Stem Cells after Injury through Novel Epigenetic Signaling via Histone 3 Regulation

Ischemic heart disease can lead to myocardial infarction (MI), a major cause of morbidity and mortality worldwide. Multiple stem cell types have been safely transferred into failing human hearts, but the overall clinical cardiovascular benefits have been modest. Therefore, there is a dire need to understand the basic biology of stem cells to enhance therapeutic effects. Bmi1 is part of the polycomb repressive complex 1 (PRC1) that is involved in different processes including proliferation, survival and differentiation of stem cells. We isolated cortical bones stem cells (CBSCs) from bone stroma, and they express significantly high levels of Bmi1 compared to mesenchymal stem cells (MSCs) and cardiac-derived stem cells (CDCs). Using lentiviral transduction, Bmi1 was knocked down in the CBSCs to determine the effect of loss of Bmi1 on proliferation and survival potential with or without Bmi1 in CBSCs. Our data show that with the loss of Bmi1, there is a decrease in CBSC ability to proliferate and survive during stress. This loss of functionality is attributed to changes in histone modification, specifically histone 3 lysine 27 (H3K27). Without the proper epigenetic regulation, due to the loss of the polycomb protein in CBSCs, there is a significant decrease in cell cycle proteins, including Cyclin B, E2F, and WEE as well as an increase in DNA damage genes, including ataxia-telangiectasia mutated (ATM) and ATM and Rad3-related (ATR). In conclusion, in the absence of Bmi1, CBSCs lose their proliferative potential, have increased DNA damage and apoptosis, and more cell cycle arrest due to changes in epigenetic modifications. Consequently, Bmi1 plays a critical role in stem cell proliferation and survival through cell cycle regulation, specifically in the CBSCs. This regulation is associated with the histone modification and regulation of Bmi1, therefore indicating a novel mechanism of Bmi1 and the epigenetic regulation of stem cells.     

Radiative heat transfer analysis of non-Newtonian dusty Casson fluid flow along a complex wavy surface

In this article, numerical solutions are obtained to observe the influence of thermal radiation on Casson particulate suspension flow past a complex isothermal wavy surface. Rosseland diffusion approximation is employed to express the contribution of radiative heat flux over the Casson fluid model. Using coordinate transformations, the two-phase model is converted into a suitable form and then integrated numerically by employing implicit finite-difference method. The numerical results are discussed in detail in terms of shear stress, rate of heat transfer, streamlines, and isotherms. It is found that the rate of heat transfer increases extensively when radiation parameter and mass concentration parameter are penetrated into the mechanism.     

Proportional-Resonant and Slide Mode Control for Single-Phase UPS Inverter

Slide mode control (SMC) is recognized as the most robust control with high stability, while the proportional-resonant (PR) control shapes the output waveform closely according to the reference sinusoidal signal. Keeping in view the characteristics of slide mode and PR control, a cascaded controller is proposed for bipolar single-phase uninterruptible power supply (UPS) inverter. The outer voltage loop uses the PR control while the inner loop uses the SMC. Chattering in the SMC has been removed using smoothed control law in narrow boundary layer condition. The stability of the controller has been analyzed using Lypunov stability criteria. The smoothed control law applied to the pulse width modulator results in fixed switching frequency of the inverter. The performance of the controller has been analyzed for single-phase inverter through simulations and experiments for both the linear and non-linear loads. The performance of controller has been compared with the other techniques of SMC and standard controllers. The proposed controller shows significant improvement in terms of reducing the total harmonics distortion to 0.5% for linear load and 1.25% for non-linear load, strong robustness, and fast response time of only 0.3 ms.