85 research outputs found

    Nonlinear Analysis of Rayleigh-Taylor Instability of Cylindrical Flow With Heat and Mass Transfer

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    We study the nonlinear Rayleigh-Taylor instability of the interface between two viscous fluids, when the phases are enclosed between two horizontal cylindrical surfaces coaxial with the interface, and when there is mass and heat transfer across the interface. The fluids are considered to be viscous and incompressible with different kinematic viscosities. The method of multiple expansions has been used for the investigation. In the nonlinear theory, it is shown that the evolution of the amplitude is governed by a Ginzburg-Landau equation. The various stability criteria are discussed both analytically and numerically and stability diagrams are obtained. It has been observed that the heat and mass transfer has stabilizing effect on the stability of the system in the nonlinear analysis

    Aspergillus spp., a versatile cell factory for enzymes and metabolites: Interventions through genome editing

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    Aspergillus sp. is widely distributed in nature and plays significant roles in the degradation of lignocellulose biomass and extensively used in bioprocess and fermentation technology and many species are also a generally regarded safe. Many of the Aspergillus species are established cell factories due to their inherent capacity in secreting large number of hydrolytic enzymes. With the advent of next generation genomic technologies and metabolic engineering technologies, the production potential of Aspergillus cell factory has improved over the years. Various genome editing tools has been developed for Aspergillus like engineered nucleases, zinc finger nucleases, TALEN and CRISPR-Cas9 system. Currently, the CRISPR/Cas9-based technique is extensively used to enhance the effectiveness of gene manipulation in model system Aspergillus nidulans and other strains like Aspergillus oryzae, Aspergillus niger and Aspergillus fumigatus. This review describes the recent developments of genome editing technologies in Aspergillus the synthesis of heterologous proteins and secondary metabolites in the Aspergillus species

    Bacillales: From Taxonomy to Biotechnological and Industrial Perspectives

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    first_page settings Order Article Reprints Open AccessReview Bacillales: From Taxonomy to Biotechnological and Industrial Perspectives by Sharareh Harirchi 1 [ORCID] , Taner Sar 1 [ORCID] , Mohaddaseh Ramezani 2, Habibu Aliyu 3 [ORCID] , Zahra Etemadifar 4 [ORCID] , Seyed Ali Nojoumi 5,6 [ORCID] , Fatemeh Yazdian 7, Mukesh Kumar Awasthi 8 [ORCID] and Mohammad J. Taherzadeh 1,* [ORCID] 1 Swedish Centre for Resource Recovery, University of Borås, 50190 Borås, Sweden 2 Microorganisms Bank, Iranian Biological Resource Centre (IBRC), Academic Center for Education, Culture and Research (ACECR), Tehran, Iran 3 Institute of Process Engineering in Life Science II: Technical Biology, Karlsruhe Institute of Technology, 76131 Karlsruhe, Germany 4 Department of Cell and Molecular Biology & Microbiology, Faculty of Biological Science and Technology, University of Isfahan, Isfahan 8174673441, Iran 5 Microbiology Research Center, Pasteur Institute of Iran, Tehran 1316943551, Iran 6 Department of Mycobacteriology and Pulmonary Research, Pasteur Institute of Iran, Tehran 1316943551, Iran 7 Department of Life Science Engineering, Faculty of New Sciences and Technologies, University of Tehran, Tehran 1439957131, Iran 8 College of Natural Resources and Environment, Northwest A&F University, Taicheng Road 3#, Yangling, Xianyang 712100, China * Author to whom correspondence should be addressed. Microorganisms 2022, 10(12), 2355; https://doi.org/10.3390/microorganisms10122355 Received: 26 October 2022 / Revised: 18 November 2022 / Accepted: 21 November 2022 / Published: 28 November 2022 (This article belongs to the Section Microbial Biotechnology) Download Browse Figure Versions Notes Abstract For a long time, the genus Bacillus has been known and considered among the most applicable genera in several fields. Recent taxonomical developments resulted in the identification of more species in Bacillus-related genera, particularly in the order Bacillales (earlier heterotypic synonym: Caryophanales), with potential application for biotechnological and industrial purposes such as biofuels, bioactive agents, biopolymers, and enzymes. Therefore, a thorough understanding of the taxonomy, growth requirements and physiology, genomics, and metabolic pathways in the highly diverse bacterial order, Bacillales, will facilitate a more robust designing and sustainable production of strain lines relevant to a circular economy. This paper is focused principally on less-known genera and their potential in the order Bacillales for promising applications in the industry and addresses the taxonomical complexities of this order. Moreover, it emphasizes the biotechnological usage of some engineered strains of the order Bacillales. The elucidation of novel taxa, their metabolic pathways, and growth conditions would make it possible to drive industrial processes toward an upgraded functionality based on the microbial nature

    In-Vessel Co-Composting of Food Waste Employing Enriched Bacterial Consortium

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    Svrha je ovoga rada bila pripremiti odgovarajuću smjesu za kompostiranje s pomoću kulture bakterija i 2 % vapna za učinkovitu obradu otpada od hrane u posudi zapremnine 60 litara. U pokusu, koji je trajao 42 dana, otpaci su od hrane prvo pomiješani s piljevinom i 2 % (suhe tvari) vapna, zatim je u jedan reaktor dodana obogaćena kultura bakterija, dok se u drugom reaktoru nalazio kontrolni uzorak. Rezultati pokazuju da se inokuliranjem smjese za kompostiranje bakterijskom kulturom može uspješno riješiti problem zasićenosti uljem te poboljšati mineralizacija. Osim toga, parametri kao što su: emisija ugljičnog dioksida od (0,81±0,2) g/(kg·dan), indeks klijanja od (105±3) %, maseni udjel ekstraktibilnog amonijaka od 305,78 mg/kg, omjer ugljika i dušika od 16,18, pH=7,6 i električna vodljivost od 3,12 mS/cm potvrđuju zrelost komposta, koji je zadovoljio standarde kompostiranja. U kontrolnom je uzorku opaženo kašnjenje termofilne faze, pa kompost nije sazrio ni nakon 42 dana. Stoga je zaključeno da su dobro pripremljena smjesa za kompostiranje i bakterijska kultura s odgovarajućim svojstvima za razgradnju ulja nužni za uspješan sustav kompostiranja otpada od hrane.The aim of the present study is to develop a good initial composting mix using a bacterial consortium and 2 % lime for effective co-composting of food waste in a 60-litre in-vessel composter. In the experiment that lasted for 42 days, the food waste was first mixed with sawdust and 2 % lime (by dry mass), then one of the reactors was inoculated with an enriched bacterial consortium, while the other served as control. The results show that inoculation of the enriched natural bacterial consortium effectively overcame the oil-laden co-composting mass in the composter and increased the rate of mineralization. In addition, CO2 evolution rate of (0.81±0.2) g/(kg·day), seed germination index of (105±3) %, extractable ammonium mass fraction of 305.78 mg/kg, C/N ratio of 16.18, pH=7.6 and electrical conductivity of 3.12 mS/cm clearly indicate that the compost was well matured and met the composting standard requirements. In contrast, control treatment exhibited a delayed thermophilic phase and did not mature after 42 days, as evidenced by the maturity parameters. Therefore, a good composting mix and potential bacterial inoculum to degrade the oil are essential for food waste co-composting systems

    High level xylitol production by Pichia fermentans using non-detoxified xylose-rich sugarcane bagasse and olive pits hydrolysates

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    Hemicellulosic sugars, the overlooked fraction of lignocellulosic residues can serve as potential and cost-effective raw material that can be exploited for xylitol production. Xylitol is a top platform chemical with applications in food and pharmaceutical industries. Sugarcane bagasse (SCB) and olive pits (OP) are the major waste streams from sugar and olive oil industries, respectively. The current study evaluated the potential of Pichia fermentans for manufacturing of xylitol from SCB and OP hydrolysates through co-fermentation strategy. The highest xylitol accumulation was noticed with a glucose and xylose ratio of 1:10 followed by feeding with xylose alone. The fed-batch cultivation using pure xylose, SCB, and OP hydrolysates, resulted in xylitol accumulation of 102.5, 86.6 and 71.9 g/L with conversion yield of 0.78, 0.75 and 0.74 g/g, respectively. The non-pathogenic behaviour and ability to accumulate high xylitol levels from agro-industrial residues demonstrates the potential of P. fermentans as microbial cell factory

    Process optimization for recycling of bread waste into bioethanol and biomethane: a circular economy approach

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    Bread is the second most wasted food in the UK with annual wastage of 292,000 tons. In the present work, bread waste (BW) was utilized for fermentative production of ethanol by Saccharomyces cerevisiae KL17. Acidic and enzymatic saccharification of BW was carried out resulting in the highest glucose release of 75 and 97.9 g/L which is 73.5 and 95.9% of theoretical yield, respectively. The obtained sugars were fermented into ethanol initially in shake flask followed by scale up in bioreactor in batch and fed-batch mode. In the fed-batch mode of cultivation, the maximum ethanol titers of 111.3, 106.9, and 114.9 g/L with conversion yield and productivity of 0.48, 0.47, and 0.49 g/g, and 3.1, 3.0, and 3.2 g/L.h was achieved from pure glucose, glucose-rich acidic and enzymatic hydrolysates, respectively. Further to improve the process economics, the solid residues after acidic (ABW) and enzymatic (EBW) hydrolysis of BW along with respective fermentation residues (FR) obtained after the ethanol production were pooled and subjected to anaerobic digestion. The solid residue from ABW + FR, and EBW + FR yielded a biochemical methanation potential (BMP) of 345 and 379 mL CH4/g VS, respectively. Life cycle assessment of the process showed that the total emissions for ethanol production from BW were comparable to the emissions from more established feedstocks such as sugarcane and maize grain and much lower when compared to wheat and sweet potato. The current work demonstrates BW as promising feedstock for sustainable biofuel production with the aid of circular biorefining strategy. To the authors knowledge, this is the first time, such a sequential system has been investigated with BW for ethanol and biomethane production. Further work will be aimed at ethanol production at pilot scale and BMP will be accessed in a commercial anaerobic digester

    Design and applications of photobioreactors - A review

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    There has been increasing attention in recent years on the use of photobioreactors for various biotechnological applications, especially for the cultivation of microalgae. Photobioreactors-based production of photosynthetic microorganisms furnish several advantages as minimising toxicity and providing improved conditions. However, the designing and scaling-up of photobioreactors (PBRs) remain a challenge. Due to huge capital investment and operating cost, there is a deficiency of suitable PBRs for development of photosynthetic microorganisms on large-scale. It is, therefore, highly desirable to understand the current state-of-the-art PBRs, their advantages and limitations so as to classify different PBRs as per their most suited applications. This review provides a holistic overview of the discreet features of diverse PBR designs and their purpose in microalgae growth and biohydrogen production and also summarizes the recent development in use of hybrid PBRs to increase their working efficiency and overall economics of their operation for the production of value-added products

    A critical assessment of technical advances in pharmaceutical removal from wastewater – A critical review

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    Use of pharmaceutical products has seen a tremendous increase in the recent decades. It has been observed that more than thirty million tons of pharmaceuticals are consumed worldwide. The used pharmaceutical products are not completely metabolized in human and animal body. Therefore, they are excreted to the environment and remain there as persistent organic chemicals. These compounds emerge as toxic contaminants in water and affect the human metabolism directly or indirectly. This literature review is an endeavour to understand the origin, applications and current advancement in the removal of pharmaceuticals from the environment. It discusses about the pharmaceuticals used in medical applications such diagnosis and disease treatment. In addition, it discusses about the recent approaches applied in pharmaceutical removal including microbial fuel cells, biofiltration, and bio nanotechnology approaches. Moreover, the challenges associated with pharmaceutical removal are presented considering biological and environmental factors. The review suggest the potential recommendations on pharmaceutical removal.The corresponding author Prof. Vinay Kumar is thankful to all the co-authors for their collaborative efforts in writing this paper. This work was supported by Department of Community Medicine, Saveetha Medical College and Hospital, Saveetha Institute of Medical and Technical Sciences (SIMATS), Chennai, India.Peer reviewe

    Global, regional, and national under-5 mortality, adult mortality, age-specific mortality, and life expectancy, 1970–2016: a systematic analysis for the Global Burden of Disease Study 2016

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    BACKGROUND: Detailed assessments of mortality patterns, particularly age-specific mortality, represent a crucial input that enables health systems to target interventions to specific populations. Understanding how all-cause mortality has changed with respect to development status can identify exemplars for best practice. To accomplish this, the Global Burden of Diseases, Injuries, and Risk Factors Study 2016 (GBD 2016) estimated age-specific and sex-specific all-cause mortality between 1970 and 2016 for 195 countries and territories and at the subnational level for the five countries with a population greater than 200 million in 2016. METHODS: We have evaluated how well civil registration systems captured deaths using a set of demographic methods called death distribution methods for adults and from consideration of survey and census data for children younger than 5 years. We generated an overall assessment of completeness of registration of deaths by dividing registered deaths in each location-year by our estimate of all-age deaths generated from our overall estimation process. For 163 locations, including subnational units in countries with a population greater than 200 million with complete vital registration (VR) systems, our estimates were largely driven by the observed data, with corrections for small fluctuations in numbers and estimation for recent years where there were lags in data reporting (lags were variable by location, generally between 1 year and 6 years). For other locations, we took advantage of different data sources available to measure under-5 mortality rates (U5MR) using complete birth histories, summary birth histories, and incomplete VR with adjustments; we measured adult mortality rate (the probability of death in individuals aged 15-60 years) using adjusted incomplete VR, sibling histories, and household death recall. We used the U5MR and adult mortality rate, together with crude death rate due to HIV in the GBD model life table system, to estimate age-specific and sex-specific death rates for each location-year. Using various international databases, we identified fatal discontinuities, which we defined as increases in the death rate of more than one death per million, resulting from conflict and terrorism, natural disasters, major transport or technological accidents, and a subset of epidemic infectious diseases; these were added to estimates in the relevant years. In 47 countries with an identified peak adult prevalence for HIV/AIDS of more than 0·5% and where VR systems were less than 65% complete, we informed our estimates of age-sex-specific mortality using the Estimation and Projection Package (EPP)-Spectrum model fitted to national HIV/AIDS prevalence surveys and antenatal clinic serosurveillance systems. We estimated stillbirths, early neonatal, late neonatal, and childhood mortality using both survey and VR data in spatiotemporal Gaussian process regression models. We estimated abridged life tables for all location-years using age-specific death rates. We grouped locations into development quintiles based on the Socio-demographic Index (SDI) and analysed mortality trends by quintile. Using spline regression, we estimated the expected mortality rate for each age-sex group as a function of SDI. We identified countries with higher life expectancy than expected by comparing observed life expectancy to anticipated life expectancy on the basis of development status alone. FINDINGS: Completeness in the registration of deaths increased from 28% in 1970 to a peak of 45% in 2013; completeness was lower after 2013 because of lags in reporting. Total deaths in children younger than 5 years decreased from 1970 to 2016, and slower decreases occurred at ages 5-24 years. By contrast, numbers of adult deaths increased in each 5-year age bracket above the age of 25 years. The distribution of annualised rates of change in age-specific mortality rate differed over the period 2000 to 2016 compared with earlier decades: increasing annualised rates of change were less frequent, although rising annualised rates of change still occurred in some locations, particularly for adolescent and younger adult age groups. Rates of stillbirths and under-5 mortality both decreased globally from 1970. Evidence for global convergence of death rates was mixed; although the absolute difference between age-standardised death rates narrowed between countries at the lowest and highest levels of SDI, the ratio of these death rates-a measure of relative inequality-increased slightly. There was a strong shift between 1970 and 2016 toward higher life expectancy, most noticeably at higher levels of SDI. Among countries with populations greater than 1 million in 2016, life expectancy at birth was highest for women in Japan, at 86·9 years (95% UI 86·7-87·2), and for men in Singapore, at 81·3 years (78·8-83·7) in 2016. Male life expectancy was generally lower than female life expectancy between 1970 and 2016, an
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