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1.
Advancing Agrobacterium-Based Crop Transformation and Genome Modification Technology for Agricultural Biotechnology.
Anand, A, Jones, TJ
Current topics in microbiology and immunology. 2018;:489-507
Abstract
The last decade has seen significant strides in Agrobacterium-mediated plant transformation technology. This has not only expanded the number of crop species that can be transformed by Agrobacterium, but has also made it possible to routinely transform several recalcitrant crop species including cereals (e.g., maize, sorghum, and wheat). However, the technology is limited by the random nature of DNA insertions, genotype dependency, low frequency of quality events, and variation in gene expression arising from genomic insertion sites. A majority of these deficiencies have now been addressed by improving the frequency of quality events, developing genotype-independent transformation capability in maize, developing an Agrobacterium-based site-specific integration technology for precise gene targeting, and adopting Agrobacterium-delivered CRISPR-Cas genes for gene editing. These improved transformation technologies are discussed in detail in this chapter.
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2.
Synthesis of non-canonical branched-chain amino acids in Escherichia coli and approaches to avoid their incorporation into recombinant proteins.
Reitz, C, Fan, Q, Neubauer, P
Current opinion in biotechnology. 2018;:248-253
Abstract
In E. coli the non-canonical amino acids acids norvaline, norleucine, and β-methylnorleucine, which derive from an off-pathway of the branched-chain amino acid synthesis route are synthesized and incorporated into cellular and recombinant proteins. The synthesis of these amino acids is supported by a high flux of glucose through the glycolytic pathway in combination with a derepression of the enzymes of the branched chain amino acid pathway, for example, when leucine-rich proteins are produced. Avoiding the synthesis and misincorporation of these amino acids has been challenging, especially in large-scale pharmaceutical processes where the problem is boosted by the typical fed-batch production and the technical limitation of mass transfer in the bioreactors. Despite its industrial importance, so far this issue has not been discussed comprehensively. Therefore this paper reviews, firstly, the specific pathway of the non-canonical branched chain amino acids starting at pyruvate, secondly, the molecular factors for their misincorporation, and thirdly, approaches to avoid this misincoporation. While the synthesis of these amino acids is difficult to prevent due to the broad promiscuity of the connected enzymes, recent studies on the control mechanisms of aminoacyl tRNA synthetases open new opportunities to avoid this misincorporation.
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3.
Specialized Plant Metabolism Characteristics and Impact on Target Molecule Biotechnological Production.
Matsuura, HN, Malik, S, de Costa, F, Yousefzadi, M, Mirjalili, MH, Arroo, R, Bhambra, AS, Strnad, M, Bonfill, M, Fett-Neto, AG
Molecular biotechnology. 2018;(2):169-183
Abstract
Plant secondary metabolism evolved in the context of highly organized and differentiated cells and tissues, featuring massive chemical complexity operating under tight environmental, developmental and genetic control. Biotechnological demand for natural products has been continuously increasing because of their significant value and new applications, mainly as pharmaceuticals. Aseptic production systems of plant secondary metabolites have improved considerably, constituting an attractive tool for increased, stable and large-scale supply of valuable molecules. Surprisingly, to date, only a few examples including taxol, shikonin, berberine and artemisinin have emerged as success cases of commercial production using this strategy. The present review focuses on the main characteristics of plant specialized metabolism and their implications for current strategies used to produce secondary compounds in axenic cultivation systems. The search for consonance between plant secondary metabolism unique features and various in vitro culture systems, including cell, tissue, organ, and engineered cultures, as well as heterologous expression in microbial platforms, is discussed. Data to date strongly suggest that attaining full potential of these biotechnology production strategies requires being able to take advantage of plant specialized metabolism singularities for improved target molecule yields and for bypassing inherent difficulties in its rational manipulation.
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4.
Recent advances on biological production of difructose dianhydride III.
Zhu, Y, Yu, S, Zhang, W, Zhang, T, Guang, C, Mu, W
Applied microbiology and biotechnology. 2018;(7):3007-3015
Abstract
Difructose dianhydride III (DFA III) is a cyclic difructose containing two reciprocal glycosidic linkages. It is easily generated with a small amount by sucrose caramelization and thus occurs in a wide range of food-stuffs during food processing. DFA III has half sweetness but only 1/15 energy of sucrose, showing potential industrial application as low-calorie sucrose substitute. In addition, it displays many benefits including prebiotic effect, low cariogenicity property, and hypocholesterolemic effect, and improves absorption of minerals, flavonoids, and immunoglobulin G. DFA III is biologically produced from inulin by inulin fructotransferase (IFTase, EC 4.2.2.18). Plenty of DFA III-producing enzymes have been identified. The crystal structure of inulin fructotransferase has been determined, and its molecular modification has been performed to improve the catalytic activity and structural stability. Large-scale production of DFA III has been studied by various IFTases, especially using an ultrafiltration membrane bioreactor. In this article, the recent findings on physiological effects of DFA III are briefly summarized; the research progresses on identification, expression, and molecular modification of IFTase and large-scale biological production of DFA III by IFTase are reviewed in detail.
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5.
A review on sustainable yeast biotechnological processes and applications.
Nandy, SK, Srivastava, RK
Microbiological research. 2018;:83-90
Abstract
Yeast is very well known eukaryotic organism for its remarkable biodiversity and extensive industrial applications. Saccharomyces cerevisiae is one of the most widely used microorganisms in biotechnology with successful applications in the biochemical production. Biological conversion with the focus on the different utilization of renewable feedstocks into fuels and chemicals has been intensively investigated due to increasing concerns on sustainability issues worldwide. Compared with its counterparts, Saccharomyces cerevisiae, the baker's yeast, is more industrially relevant due to known genetic and physiological background, the availability of a large collection of genetic tools, the compatibility of high-density and large-scale fermentation, and optimize the pathway for variety of products. Therefore, S. cerevisiae is one of the most popular cell factories and has been successfully used in the modern biotech industry to produce a wide variety of products such as ethanol, organic acids, amino acids, enzymes, and therapeutic proteins. This study explores how different sustainable solutions used to overcome various environmental effects on yeast. This work targets a broad matrix of current advances and future prospect in yeast biotechnology and discusses their application and potential in general.
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6.
Biotechnological Approaches for the Production of Pharmaceutically Important Compound: Plumbagin.
Roy, A, Bharadvaja, N
Current pharmaceutical biotechnology. 2018;(5):372-381
Abstract
BACKGROUND Increased demand for compounds that are derived from natural source are gaining more and more importance. Plumbagin is a plant naphthoquinone which is present in several families, including Iridaceae, Plumbaginaceae, Ebenceae, Drosophyllaceae, Nepenthaceae and Droseraceae. Plumbagin possesses high therapeutic efficacy and minimal side effects. It has various pharmaceutical activities which include anticancer, antibacterial, anti-inflammatory, antioxidant, antifungal, neuroprotective and hypolipidemic activities. In natural habitat, production of plumbagin is low due to species variations and environmental changes, considering importance of this bioactive compound, alternative techniques for its enhanced production needs to be devised. In the present review, various production techniques and scale-up strategies for plumbagin production are discussed. OBJECTIVES Aim of this review is to provide an insight into the chemistry of plumbagin, its pharmaceutical activities, perspective of cell suspension culture, root culture, hairy root culture and scale up strategies for its production. METHODOLOGY All the data compiled and presented here were obtained from various E-resources like Pubmed, Science Direct, and Google Scholar up to February 2018. RESULT This review comprises isolation, extraction and quantification method for plumbagin, its pharmaceutical activities, various tissue culture production techniques and scale-up strategies for enhanced production. CONCLUSION Plumbagin is an important phytocompound which shows potential towards treatments of various diseases. Demand for the production of plumbagin continuously increasing worldwide due to its pharmacological properties. To fulfil commercial demand of plumbagin alternative technologies need to be investigated. Biotechnological approaches like cell suspension culture, root suspension culture and hairy root culture are alternative techniques for plumbagin production. These techniques provide continuous supply of bioactive compounds. However, research on various aspects of tissue culture production techniques is in preparatory stage and requires culture and process optimization for development of a commercially practical process.
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7.
Biotechnological approaches in glucosinolate production.
Petersen, A, Wang, C, Crocoll, C, Halkier, BA
Journal of integrative plant biology. 2018;(12):1231-1248
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Abstract
Glucosinolates (GLSs) are sulfur-rich, amino acid-derived defense compounds characteristic of the Brassicales order. In the past, GLSs were mostly known as anti-nutritional factors in fodder, biopesticides in agriculture, and flavors in condiments such as mustard. However, in recent times, GLSs have received increased attention as promoters of human health. This has spurred intensive research towards generating rich sources of health-promoting GLSs. We provide a comprehensive overview of the biotechnological approaches applied to reach this goal. This includes optimization of GLS production and composition in native, GLS-producing plants, including hairy root and cell cultures thereof, as well as synthetic biology approaches in heterologous hosts, such as tobacco and the microbial organisms Escherichia coli and Saccharomyces cerevisiae. The progress using these different approaches is discussed.
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8.
Microalgae population dynamics growth with AnMBR effluent: effect of light and phosphorus concentration.
Sanchis-Perucho, P, Duran, F, Barat, R, Pachés, M, Aguado, D
Water science and technology : a journal of the International Association on Water Pollution Research. 2018;(11-12):2566-2577
Abstract
The aim of this study was to evaluate the effect of light intensity and phosphorus concentration on biomass growth and nutrient removal in a microalgae culture and their effect on their competition. The photobioreactor was continuously fed with the effluent from an anaerobic membrane bioreactor pilot plant treating real wastewater. Four experimental periods were carried out at different light intensities (36 and 52 μmol s-1 m-2) and phosphorus concentrations (around 6 and 15 mgP L-1). Four green algae - Scenedesmus, Chlorella, Monoraphidium and Chlamydomonas- and cyanobacterium were detected and quantified along whole experimental period. Chlorella was the dominant species when light intensity was at the lower level tested, and was competitively displaced by a mixed culture of Scenedesmus and Monoraphidium when light was increased. When phosphorus concentration in the photobioreactor was raised up to 15 mgP L-1, a growth of cyanobacterium became the dominant species in the culture. The highest nutrient removal efficiency (around 58.4 ± 15.8% and 96.1 ± 16.5% of nitrogen and phosphorus, respectively) was achieved at 52 μmol s-1 m-2 of light intensity and 6.02 mgP L-1 of phosphorus concentration, reaching about 674 ± 86 mg L-1 of volatile suspended solids. The results obtained reveal how the light intensity supplied and the phosphorus concentration available are relevant operational factors that determine the microalgae species that is able to predominate in a culture. Moreover, changes in microalgae predominance can be induced by changes in the growth medium produced by the own predominant species.
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9.
R software package based statistical optimization of process components to simultaneously enhance the bacterial growth, laccase production and textile dye decolorization with cytotoxicity study.
Bhavsar, S, Dudhagara, P, Tank, S
PloS one. 2018;(5):e0195795
Abstract
The thermophilic bacterium, Bacillus licheniformis U1 is used for the optimization of bacterial growth (R1), laccase production (R2) and synthetic disperse blue DBR textile dye decolorization (R3) in the present study. Preliminary optimization has been performed by one variable at time (OVAT) approach using four media components viz., dye concentration, copper sulphate concentration, pH, and inoculum size. Based on OVAT result further statistical optimization of R1, R2 and R3 performed by Box-Behnken design (BBD) using response surface methodology (RSM) in R software with R Commander package. The total 29 experimental runs conducted in the experimental design study towards the construction of a quadratic model. The model indicated that dye concentration 110 ppm, copper sulphate 0.2 mM, pH 7.5 and inoculum size 6% v/v were found to be optimum to maximize the laccase production and bacterial growth. Whereas, maximum dye decolorization achieved in media containing dye concentration 110 ppm, copper sulphate 0.6 mM, pH 6 and inoculum size 6% v/v. R package predicted R2 of R1, R2 and R3 were 0.9917, 0.9831 and 0.9703 respectively; likened to Design-Expert (Stat-Ease) (DOE) predicted R2 of R1, R2, and R3 were 0.9893, 0.9822 and 0.8442 respectively. The values obtained by R software were more precise, reliable and reproducible, compared to the DOE model. The laccase production was 1.80 fold increased, and 2.24 fold enhancement in dye decolorization was achieved using optimized medium than initial experiments. Moreover, the laccase-treated sample demonstrated the less cytotoxic effect on L132 and MCF-7 cell lines compared to untreated sample using MTT assay. Higher cell viability and lower cytotoxicity observed in a laccase-treated sample suggest the impending application of bacterial laccase in the reduction of toxicity of dye to design rapid biodegradation process.
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10.
Graphene and graphene oxide: Functionalization and nano-bio-catalytic system for enzyme immobilization and biotechnological perspective.
Adeel, M, Bilal, M, Rasheed, T, Sharma, A, Iqbal, HMN
International journal of biological macromolecules. 2018;(Pt B):1430-1440
Abstract
Graphene-based nanomaterials have gained high research interest in different fields related to proteins and thus are rapidly becoming the most widely investigated carbon-based materials. Their exceptional physiochemical properties such as electrical, optical, thermal and mechanical strength enable graphene to render graphene-based nanostructured materials suitable for applications in different fields such as electroanalytical chemistry, electrochemical sensors and immobilization of biomolecules and enzymes. The structural feature of oxygenated graphene, i.e., graphene oxide (GO) covered with different functionalities such as epoxy, hydroxyl, and carboxylic group, open a new direction of chemical modification of GO with desired properties. This review describes the recent progress related to the structural geometry, physiochemical characteristics, and functionalization of GO, and the development of graphene-based novel carriers as host for enzyme immobilization. Graphene derivatives-based applications are progressively increasing, in recent years. Therefore, from the bio-catalysis and biotransformation viewpoint, the biotechnological perspective of graphene-immobilized nano-bio-catalysts is of supreme interest. The structural geometry, unique properties, and functionalization of graphene derivatives and graphene-based nanomaterials as host for enzyme immobilization are highlighted in this review. Also, the role of GO-based catalytic systems such as microfluidic bio-catalysis, enzyme-based biofuel cells, and biosensors are also discussed with potential future perspectives of these multifaceted materials.