Bottleneck In Production Research Articles

Management of bacterial leaf blight of rice using plant extracts

Xanthomonas oryzae pv. oryzae, the incitant of bacterial leaf blight disease of rice acts as a bottleneck in productivity of rice. Chemical control measures impose hazards to human as well as soil health. So, there is always a quest for eco-friendly management strategies. In vitro and in vivo assays were employed to evaluate the sensitivity of the pathogen against crude aqueous extracts of different plants. Out of five plant extracts, Datura metel was most effective in restricting the pathogen followed by Allium sativum. The percent inhibition exhibited by D. metel extract were 46.73% and 58.04% at 15% and 20% concentrations, respectively. Aqueous extract spray of D. metel at 20% proved effective in restricting the disease by 11.9% and recorded 104% yield increase over control.

Pearl Millet (Pennisetum glaucum L.) Breeding for Adaptation and Performance Under Drought Condition: Review

Drought stress is one of abiotic factor that threat crops economic part directly and indirectly; hence, result great yield losses in the world and become predominant cause for food security problem especially in developing countries. Pear millet is staple food crop used in different countries. It is widely produced around drought-prone arid and semi-arid regions where inter and intera seasonal rainfall variation of the areas become bottleneck for pear millet production. Thus, the current review conducted to understand pearl millet breeding for adaptation and performance under drought condition. From gene point of view crops drought resistance mechanism grouped in to drought escape, drought avoidance and drought tolerance. In all these three mechanisms crops express different control characteristics to overcome drought stress problem. Plants can use more than one mechanisms at same time based on regulators gene they posses for drought tolerance. Pear millet has huge noble traits such as rapid phonological development (early flowering which enables to escape), plasticity growth characteristics (tillering), deep and wider spread root growth and high water use efficiency those attribute for its adaptation and performance under drought stress. Both conventional and molecular breeding methods had being utilized and also currently under utilization for pear millet improvement for drought tolerance. Better performing genotypes selection and hybridization done conventionally and crosses were showed 66% heterosis over best parents in grain yield under stress; whereas marker assisted selection of QTL used for transfer of drought tolerant gene from drought tolerant genotype to drought susceptible genotype but, has good agronomic performance done using molecular breeding method. Hence, over 30% high yielders variety developed for drought threatens environments. Keywords: Breeding method, drought stress, early flowering, Pear millet and tiller DOI: 10.7176/JEES/10-4-01 Publication date: April 30 th 2020

Microwave-assisted in situ transesterification of wet microalgae for the production of biodiesel: progress review

Continuous efforts are done by scientists in the quest of finding sustainable alternatives for fossil fuels. Various feedstock have been carefully selected to be utilized in the production of biodiesel. Microalgae has garnered a lot of attention as early as in the 80s and is regarded as one of the most promising feedstock to displace fossil fuel. However, the utilization of microalgae as feedstock in a mass production of biodiesel comes with considerable challenges. One of the main obstacles is the high cost involved in processes such as drying and the subsequent lipid extraction of the biomass. These two energy extensive processes created a bottleneck in the biodiesel production at a large scale. As a remedy, direct or in situ transesterification of the wet microalgae biomass can be applied to entirely circumvent the two processes; hence substantially reducing the production cost. However, the presence of water in the wet microalgae biomass posed a challenge in the transesterification process. This paper covers the specific techniques of utilizing microwave irradiation during the in situ transesterification of wet microalgae biomass.

High‐yield production of hematopoietic growth factors by tobacco BY‐2 cells for ex vivo production of red blood cells

Ex vivo generation of clinically available red blood cells (RBCs) from hematopoietic stem cells (HSCs) represents a promising approach for overcoming the limitations associated with the use of donor’s blood, such as shortage of blood and risk of transfusion‐transmitted infections. Both expansion and differentiation of stem cells are highly reliant on growth and differentiation factors, with the activity and purity of these molecules being critical to successful research and clinical applications. The overarching goal of this project is to develop a novel plant cell‐based bioproduction platform for high‐quality (i.e. animal‐free and endotoxin‐free) erythropoietic growth factors (eGFs) that facilitate mass production of RBCs from HSCs at significantly reduced cost. In addressing the low productivity bottleneck of plant cell culture technology, this proposal aims to leverage a unique, plant‐specific, O‐glycosylation process called “hydroxyproline (Hyp)‐O‐glycosylation” for de novo design and engineering of Hyp‐O‐ glycosylated peptides (HypGPs”) that presumably function as a molecular carrier in boosting secretion of conjoined eGFs from cultured plant cells. This will dramatically increase the secreted yields of plant cell‐derived eGFs and simplify the product purification process. Three key eGFs essential for HSCs expansion and differentiation: erythropoietin (EPO), stem cell factor (SCF) and interleukin 3 (IL‐3), are expressed in tobacco BY‐2 cells as fusion with a strategically designed HypGP tag. The secreted protein yields, molecular structure, and Hyp‐O‐glycosylation of the HypGP‐tagged eGFs are characterized. The bioactivities of individual HypGP‐tagged eGF in stimulating proliferation and differentiation of relevant hematopoietic cell lines, includingTF1 erythroleukemic cell and umbilical cord blood‐derived CD34+ cell, are evaluated to establish a suitable design of HypGP tag (size and orientation) for each eGF. A scalable cell culture system fortified sorely with plant cell‐produced eGFs is developed for production of RBCs from CD34+ HSC cells. This project provides a proof‐of‐concept for ex vivo manufacturing of stem cell‐derived RBCs with plant cell‐produced eGFs.Support or Funding InformationNational Science Foundation Directorate for Engineering [1605564]; National Institutes of Health‐Arkansas INBRE [P20GM103429]

High-effective biosynthesis of baccatin Ⅲ by using the alternative acetyl substrate, N-acetyl-d-glucosamine.

Paclitaxel is a type of broad-spectrum anticancer drug in short supply. The price of acetyl-CoA (17709677·4 USDmol-1 ), which is the acetyl group donor for the enzymatic synthesis of the intermediate, baccatin Ⅲ, is still the bottleneck of the mass production of paclitaxel. This study reports a novel acetyl group donor, which could substantially reduce the cost of production. In this study, a substrate spectrum with 14 kinds of representative acetyl-donor substitutes predicted by computer-aided methods was tested in a 10-deacetylbaccatin Ⅲ-10-O-acetyltransferase (DBAT) heterogeneous-expressed open-whole-cell catalytic system. The results of computer prediction and experimental analysis revealed the rule of the acetyl-donor compounds based on this substrate spectrum. N-acetyl-d-glucosamine (30·95 USDmol-1 , about 572202-fold cheaper than acetyl-CoA) is selected as a suitable substitute under the rule. The yield when using N-acetyl-d-glucosamine as acetyl donor in open-whole-cell catalytic system was 2·13-fold of that when using acetyl-CoA. In the in vivo system, the yield increased 24·17%, which may indicate its cooperation with acetyl-CoA. The success of open-whole-cell synthesis and in vivo synthesis of baccatin Ⅲ by adding N-acetyl-d-glucosamine as acetyl substrate demonstrates that it is a useful substrate to improve the yield of baccatin Ⅲ. All these findings provided a potential acetyl-donor substitute for acetyl-CoA, as well as a low cost and efficient method of preparing paclitaxel through baccatin Ⅲ semi-synthesis.

Industrial Production of Poly-β-hydroxybutyrate from CO2: Can Cyanobacteria Meet this Challenge?

The increasing impact of plastic materials on the environment is a growing global concern. In regards to this circumstance, it is a major challenge to find new sources for the production of bioplastics. Poly-β-hydroxybutyrate (PHB) is characterized by interesting features that draw attention for research and commercial ventures. Indeed, PHB is eco-friendly, biodegradable, and biocompatible. Bacterial fermentation processes are a known route to produce PHB. However, the production of PHB through the chemoheterotrophic bacterial system is very expensive due to the high costs of the carbon source for the growth of the organism. On the contrary, the production of PHB through the photoautotrophic cyanobacterium system is considered an attractive alternative for a low-cost PHB production because of the inexpensive feedstock (CO2 and light). This paper regards the evaluation of four independent strategies to improve the PHB production by cyanobacteria: (i) the design of the medium; (ii) the genetic engineering to improve the PHB accumulation; (iii) the development of robust models as a tool to identify the bottleneck(s) of the PHB production to maximize the production; and (iv) the continuous operation mode in a photobioreactor for PHB production. The synergic effect of these strategies could address the design of the optimal PHB production process by cyanobacteria. A further limitation for the commercial production of PHB via the biotechnological route are the high costs related to the recovery of PHB granules. Therefore, a further challenge is to select a low-cost and environmentally friendly process to recover PHB from cyanobacteria.

Effects of biochar on ethanol-type and butyrate-type fermentative hydrogen productions

Low hydrogen yield was the bottleneck of dark fermentative hydrogen production. To solve this problem, the effects of rice straw-derived biochar on hydrogen production was investigated in different fermentation types. Ethanol-type and butyrate-type fermentations, two dominant types of dark fermentation, were carried out in batch fermentations with different concentrations of biochar. The results revealed that 3 g/L was the best concentration for both types of fermentations. Hydrogen production increased by 118.4% and 79.6% in ethanol-type and butyrate-type fermentations, respectively. The maximal hydrogen yields of ethanol-type and butyrate-type fermentations were 1.34 and 2.36 mol/mol-glucose, respectively. The addition of biochar buffered the broth pH, lowered the redox potential, and released mineral nutrients. The porosity of biochar boosted cell immobilization and thus improved the H2 productivity. This study demonstrated the enhancement effect of biochar on ethanol- and butyrate-type fermentative hydrogen productions, and enhanced the understanding of the functional mechanisms of biochar.

Overexpression of transcription factor Foxa1 and target genes remediate therapeutic protein production bottlenecks in Chinese hamster ovary cells.

Despite extensive research conducted to increase protein production from Chinese hamster ovary (CHO) cells, cellular bottlenecks often remain, hindering high yields. In this study, a transcriptomic analysis led to the identification of 32 genes that are consistently upregulated in high producer clones and thus might mediate high productivity. Candidate genes were associated with functions such as signaling, protein folding, cytoskeleton organization, and cell survival. We focused on two engineering targets, Erp27, which binds unfolded proteins and the Erp57 disulfide isomerase in the endoplasmic reticulum, and Foxa1, a pioneering transcription factor involved in organ development. Erp27 moderate overexpression increased production of an easy‐to‐express antibody, whereas Erp27 and Erp57 co‐overexpression increased cell density, viability, and the yield of difficult‐to‐express proteins. Foxa1 overexpression increased cell density, cell viability, and easy‐ and difficult‐to‐express protein yields, whereas it decreased reactive oxygen species late in fed‐batch cultures. Foxa1 overexpression upregulated two other candidate genes that increased the production of difficult‐ and/or easy‐to‐express proteins, namely Ca3, involved in protecting cells from oxidative stress, and Tagap, involved in signaling and cytoskeleton remodeling. Overall, several genes allowing to overcome CHO cell bottlenecks were identified, including Foxa1, which mediated multiple favorable metabolic changes that improve therapeutic protein yields.

Effect of two lignocellulose related sugar alcohols on the growth and metabolites biosynthesis of Euglena gracilis

It is an effective solution to overcome the bottlenecks of commercial production of microalgal biomass by providing cost-effective and environment-friendly organic carbon sources for microalgal mixotrophic growth. In this study, effects of lignocellulose-related mannitol and xylitol on the growth, photosynthetic pigment content, cell morphology, and metabolites biosynthesis of freshwater microalga Euglena gracilis were investigated. The results revealed that both mannitol and xylitol effectively promoted the growth of E. gracilis, and at the optimal dosage of 4 g·L−1, the biomass yield was increased by 4.64-fold and 3.18-fold, respectively. Increase of cell aspect ratio was only observed in mannitol treatment groups, indicating that E. gracilis had different physiological responses to mannitol and xylitol. Fourier transform infrared spectroscopy combined with multivariate analysis was applied to analyze the cellular components. The lipid content of E. gracilis was significantly promoted by these two sugar alcohols, which would increase its potential in biofuel production.

Transcriptional regulation of organohalide pollutant utilisation in bacteria

Organohalides are organic molecules formed biotically and abiotically, both naturally and through industrial production. They are usually toxic and represent a health risk for living organisms, including humans. Bacteria capable of degrading organohalides for growth express dehalogenase genes encoding enzymes that cleave carbon-halogen bonds. Such bacteria are of potential high interest for bioremediation of contaminated sites. Dehalogenase genes are often part of gene clusters that may include regulators, accessory genes and genes for transporters and other enzymes of organohalide degradation pathways. Organohalides and their degradation products affect the activity of regulatory factors, and extensive genome-wide modulation of gene expression helps dehalogenating bacteria to cope with stresses associated with dehalogenation, such as intracellular increase of halides, dehalogenase-dependent acid production, organohalide toxicity and misrouting and bottlenecks in metabolic fluxes. This review focuses on transcriptional regulation of gene clusters for dehalogenation in bacteria, as studied in laboratory experiments and in situ. The diversity in gene content, organization and regulation of such gene clusters is highlighted for representative organohalide-degrading bacteria. Selected examples illustrate a key, overlooked role of regulatory processes, often strain-specific, for efficient dehalogenation and productive growth in presence of organohalides.

Florida Citrus Nursery Trends and Strategies to Enhance Production of Field-Transplant Ready Citrus Plants

The Florida citrus industry is going through major changes and considerable replanting. Many growers are planting varieties, especially rootstocks, that are potentially productive under Huanglongbing (HLB; Candidatus Liberibacter asiaticus) prevalent conditions. However, the high demand for new plant material has put tremendous pressure on citrus nurseries and has created a bottleneck in production. Often it can take more than one year to produce field-transplant ready plants in nurseries; therefore, there is a critical need to accelerate plant production. This three-part study was conducted with the following objectives: (1) determine citrus nursery trends; (2) evaluate use of compost for rootstock germination; and, (3) evaluate use of compost for rootstock seedling growth. According to the nursery survey, rootstock seed germination and seedling growth were the most time-consuming, taking 6–8 months. Moreover, it was apparent from the survey results that 44% of the citrus nurseries were experimenting with potting mixes to achieve adequate plant growth and quality. Our greenhouse study demonstrated successful use of yard waste compost in place of peat moss in a potting mix. With use of 37% to 50% of compost in the potting mix, the overall germination rate and mean emergence time were improved to 70% in less than four weeks for US-897 rootstock as compared to no compost in the potting mix. In addition, 37% to 50% compost resulted in higher biomass accumulation in seedlings. When seedlings of rootstocks C-32 and Flying Dragon were grown with 37% to 50% compost, the growth rate and, therefore, percentage of successful budding were significantly increased as compared to no compost. In addition, substrate analysis indicated that a high compost potting media was rich in mineral nutrients, hence the use of fertilizer in nurseries could be minimized. Altogether, use of compost in place of peat moss seems promising and could accelerate germination and growth of rootstocks, reducing the production time as well as cost.

Short-term production scheduling with non-triangular sequence-dependent setup times and shifting production bottlenecks

A novel mathematical model is introduced that allows solving real-life scheduling problems in complex multi-stage machine environment with (i) non-triangular sequence-dependent setup times and (ii) shifting production bottlenecks, both of which are important aspects appearing in varying manufacturing industries. The primary goal is to minimise the tardiness of customer orders, which may consist of multiple production orders each in turn composed of several batches. A secondary objective is to maximise the production capacity utilization as measured by the makespan. The model is elaborated for general animal-feed plants which have to deal with the particular production scheduling problem on a daily basis. Dispatching rules are introduced to enhance the optimization progress. Numerical experiments show that optimising the model leads to schedules that meet the due dates. Moreover, by reducing the mean idle time of production lines with 35.6%, the optimization leads to a makespan reduction of 6.5% on average compared to real-life applied schedules.

Debottlenecking mevalonate pathway for antimalarial drug precursor amorphadiene biosynthesis in Yarrowia lipolytica

World Health Organization reports that half of the population in developing countries are at risk of malaria infection. Artemisinin, the most potent anti-malaria drug, is a sesquiterpene endoperoxide extracted from the plant Artemisia annua. Due to scalability and economics issues, plant extraction or chemical synthesis could not provide a sustainable route for large-scale manufacturing of artemisinin. The price of artemisinin has been fluctuating from 200$/Kg to 1100$/Kg, due to geopolitical and climate factors. Microbial fermentation was considered as a promising method to stabilize the artemisinin supply chain. Yarrowia lipolytica, is an oleaginous yeast with proven capacity to produce large quantity of lipids and oleochemicals. In this report, the lipogenic acetyl-CoA pathways and the endogenous mevalonate pathway of Y. lipolytica were harnessed for amorphadiene production. Gene overexpression indicate that HMG-CoA and acetyl-CoA supply are two limiting bottlenecks for amorphadiene production. We have identified the optimal HMG-CoA reductase and determined the optimal gene copy number for the precursor pathways. Amorphadiene production was improved further by either inhibiting fatty acids synthase or activating the fatty acid degradation pathway. With co-expression of mevalonate kinase (encoded by Erg12), a push-and-pull strategy enabled the engineered strain to produce 171.5 ​mg/L of amorphadiene in shake flasks. These results demonstrate that balancing carbon flux and manipulation of precursor competing pathways are key factors to improve amorphadiene biosynthesis in oleaginous yeast; and Y. lipolytica is a promising microbial host to expand nature’s biosynthetic capacity, allowing us to quickly access antimalarial drug precursors.

Sensorization of Shot Peening for Process Monitoring: Media Flow Rate Control for Surface Quality

Shot peening is a surface enhancement process that is extensively used by various industries to impart compressive residual stresses to enhance the fatigue life of the component. Almen strip system is currently used to quantify the process quality - however this method is not real-time and a common bottleneck in production due to long times associated with developing saturation curves using Almen strip. With the main objective of real time process monitoring for shot peening, Acoustic Emission (AE) sensor and accelerometer were implemented at the nozzle and experimental trials were conducted at different operating conditions. The behavior of AE sensor and accelerometer with respect to input parameters for different types of media was reported. It was concluded through this study that AE sensor and accelerometer signal when implemented on the nozzle shows initial potential. Future work includes several improvements to increase the data accuracy and reduce uncertainty; thereafter, the sensors could be used as an indirect means to monitor downstream media flow rate of the media, which affects intensity and subsequently induced compressive residual stress on the component.

Design Rules, Volume 2: Chapter 8—Rationalizing Flow Processes

The purpose of this chapter is to examine the value structure of flow production processes and to explain why it is necessary to rationalize flow processes using the tools of systematic management. I first explain the problems facing managers of multi-step flow production processes at the end of the 19th Century. I map the value structure of a production process made up of interdependent steps and define the production bottleneck of the process. I go on to derive two general properties of multi-step flow processes with bottlenecks. These properties imply a need for ongoing managerial oversight and intervention. Without active systematic management to address production bottlenecks, large-scale flow processes can easily collapse into chaos. I then argue that that the use of automated machinery, large (or growing) markets, and systematic management are supermodular complements: each attribute makes the other two more valuable. The next chapter will explore how the technological requirements of multi-step flow production processes affect the optimal design of organizations implementing these technologies.

The articles.ELM resource: simplifying access to protein linear motif literature by annotation, text-mining and classification.

Modern biology produces data at a staggering rate. Yet, much of these biological data is still isolated in the text, figures, tables and supplementary materials of articles. As a result, biological information created at great expense is significantly underutilised. The protein motif biology field does not have sufficient resources to curate the corpus of motif-related literature and, to date, only a fraction of the available articles have been curated. In this study, we develop a set of tools and a web resource, ‘articles.ELM’, to rapidly identify the motif literature articles pertinent to a researcher’s interest. At the core of the resource is a manually curated set of about 8000 motif-related articles. These articles are automatically annotated with a range of relevant biological data allowing in-depth search functionality. Machine-learning article classification is used to group articles based on their similarity to manually curated motif classes in the Eukaryotic Linear Motif resource. Articles can also be manually classified within the resource. The ‘articles.ELM’ resource permits the rapid and accurate discovery of relevant motif articles thereby improving the visibility of motif literature and simplifying the recovery of valuable biological insights sequestered within scientific articles. Consequently, this web resource removes a critical bottleneck in scientific productivity for the motif biology field. Database URL: http://slim.icr.ac.uk/articles/

An Investigation of Hydraulic-Fracturing Applied to Marine Gas Hydrate Reservoirs

Engineers have been struggling to harvest natural gas from the marine hydrates through drilling wells in the past two decades. The harvesting process has not been successful due to engineering problems such as wellbore collapse and sand production. This study proposes to use frac-packing method to address the wellbore collapse and sand production issues to break through the bottleneck of commercial production of natural gas from marine gas hydrates. An analytical model was developed to describe sequential initiation and simultaneous propagation of multiple vertical fractures in horizontal wells for frac-packing gas hydrate reservoirs. Result of sensitivity analyses with the models indicates that to frac-pack horizontal gas hydrate wells for solid-production control, increasing injection rate and flow behavior index of fracturing fluid will create more friction and thus more resistance to flow in large fractures, promoting the creation of more short fractures, and thus larger treated reservoir volume for higher gas production rate and gas recovery.

Fungal Glycoside Hydrolases of White-Rot Fungi for Cellulosic Biofuels Production: A Review

The second generation bioethanol production from lignocellulose materials through environmental friendly methods is one of the biggest challenges on industrial application. Enzymatic hydrolysis of cellulose has more benefits compared with the acid hydrolysis This method has the good specificity, low consumption of energy and chemicals and is more environmental friendly. However, the utilization of lignocellulose for bioethanol production through enzymatic methods is still confronting several difficulties for commercialization. Cellulose hydrolysis step has been reported to be the bottleneck of bioethanol production by enzymatic process, and the major barrier of this process is high price of enzymes, which making the process less economically feasible. For this reason, many developments are still needed in cellulase production from various organisms for cellulose saccharification. White-rot fungi have received much consideration for their valuable enzyme systems which can effective degrade lignocellulose biomass. These fungi could secrete extracellular oxidative and hydrolytic enzymes that degrade lignin, hemicellulose, and cellulose. This review provides a complete overview of the glycoside hydrolases enzymes production by white-rot fungus, such as endoglucanase, exoglucanase, β-glucosidase, cellobiose dehydrogenase and lytic polysaccharide monooxygenase. The use of white-rot fungus for low cost glycoside hydrolases enzymes production might be fascinating for second generation bioethanol production.

A graph-based decision support system for analyzing hybrid make-to-stock/make-to-order manufacturing environments

Goal: This paper aims to facilitate production-planning strategies for demand responsiveness. Our paper implements graph-rewriting systems towards supporting operative decision making in production environments.
 Design/Methodology/Approach: We design a decision support approach which is able to recognize and resolve conflicts amongst workstations in a hybrid production system. During the proposed stages of the presented approach, we rewrite the hybrid system by means of graph representation procedure, identify conflicts among the workstations by means of the developed graph coloring algorithm, and evaluate performance of the reorganized system by defining key performance indicators for the presented system.
 Results: We prove that the graphs’ chromatic numbers in such systems are less than or equal to entire number of dummy nodes applied to the system by means of our proposed algorithm. Furthermore, the presented structure improves the performance of the system by analyzing production bottlenecks.
 Limitations of the investigations: we only considered the Key Performance Indicators according to products, workstations, and customers. However, the problem can be more generalized by adding some more elements.
 Practical Implications: Our methodology enables managers to assess the performance of the reorganized system after applying the heuristic algorithm, by means of representing a performance evaluation procedure.
 Originality/ Value: We focus on presenting a novel structure to help companies using hybrid make-to-stock (MTS)/make-to-order (MTO) production strategies to (1) identify conflicting workstations and the relations among them, (2) propose dialectical prioritization rules and techniques by means of graph-coloring concepts for resolving the conflicts, (3) reorganize the system, and evaluate performance.

Realising the value from next generation integrated operating centres (IOC)

The oil and gas (O&G) industry has long been at the forefront of integrated operations centres (IOCs). A remote control room is often the starting point for an IOC. The control room is responsible for monitoring operations, reporting performance issues, and visualising information. In leading O&G players around the world, basic control room functionality has been enhanced by next generation IOCs that provide proactive support, including integrated planning, optimised decision models, automated procedures, and root cause analysis. This paper describes the features of advanced IOCs and their benefits: improved production (reduced production bottlenecks and increased facility runtime); enhanced organisational capability (increased process standardisation and optimised work processes); reduced risk exposure (e.g. hazardous areas and operator fatigue), reduced operational expenditure (15–25% in maintenance costs and 10–15% in logistics costs). In Australia, advanced IOC functionality and the associated benefits are yet to be widely observed. For an IOC to achieve its full potential, companies must start with a clear vision and business case for building the IOC, and how it will support the operating model. This paper details this and other recommendations that need to be considered, for example, changes to the organisation structure, ways of working, employment model, talent acquisition and development to capture value, and to develop a roadmap that delivers agility for future changes.