scholarly journals Metabolic Engineering of Fungal Strains for Conversion of d-Galacturonate to meso-Galactarate

2009 ◽  
Vol 76 (1) ◽  
pp. 169-175 ◽  
Author(s):  
Dominik Mojzita ◽  
Marilyn Wiebe ◽  
Satu Hilditch ◽  
Harry Boer ◽  
Merja Penttilä ◽  
...  
Keyword(s):  
Metabolic Engineering ◽  
Aspergillus Niger ◽  
Galacturonic Acid ◽  
Raw Material ◽  
High Yield ◽  
Hypocrea Jecorina ◽  
Bacterial Gene ◽  
Fungal Strains ◽  
Gene Coding ◽  
Reductive Pathway

ABSTRACT d-Galacturonic acid can be obtained by hydrolyzing pectin, which is an abundant and low value raw material. By means of metabolic engineering, we constructed fungal strains for the conversion of d-galacturonate to meso-galactarate (mucate). Galactarate has applications in food, cosmetics, and pharmaceuticals and as a platform chemical. In fungi d-galacturonate is catabolized through a reductive pathway with a d-galacturonate reductase as the first enzyme. Deleting the corresponding gene in the fungi Hypocrea jecorina and Aspergillus niger resulted in strains unable to grow on d-galacturonate. The genes of the pathway for d-galacturonate catabolism were upregulated in the presence of d-galacturonate in A. niger, even when the gene for d-galacturonate reductase was deleted, indicating that d-galacturonate itself is an inducer for the pathway. A bacterial gene coding for a d-galacturonate dehydrogenase catalyzing the NAD-dependent oxidation of d-galacturonate to galactarate was introduced to both strains with disrupted d-galacturonate catabolism. Both strains converted d-galacturonate to galactarate. The resulting H. jecorina strain produced galactarate at high yield. The A. niger strain regained the ability to grow on d-galacturonate when the d-galacturonate dehydrogenase was introduced, suggesting that it has a pathway for galactarate catabolism.

Six novel constitutive promoters for metabolic engineering of Aspergillus niger

2012 ◽  
Vol 97 (1) ◽  
pp. 259-267 ◽  
Author(s):  
Marzena Blumhoff ◽  
Matthias G. Steiger ◽  
Hans Marx ◽  
Diethard Mattanovich ◽  
Michael Sauer
Keyword(s):  
Metabolic Engineering ◽  
Aspergillus Niger

scholarly journals Soybean waste in particleboard production

2018 ◽  
Vol 42 (2) ◽  
pp. 186-194 ◽  
Author(s):  
Evelyn Hoffmamm Martins ◽  
Alan Pereira Vilela ◽  
Rafael Farinassi Mendes ◽  
Lourival Marin Mendes ◽  
Lívia Elisabeth Vasconcellos de Siqueira Brandão Vaz ◽  
...  
Keyword(s):  
Water Absorption ◽  
Water Immersion ◽  
Eucalyptus Grandis ◽  
Raw Material ◽  
Modulus Of Rupture ◽  
High Yield ◽  
Thickness Swelling ◽  
Randomized Design ◽  
Completely Randomized Design ◽  
Hybrid Eucalyptus

ABSTRACT Brazil is the second largest soybean producer in the world, with a yield of around 96.2 million tons per crop. This high yield leads to a great amount of waste resulting from soybean cultivation, which can reach approximately 41 million tons of waste per year. This material has lignocellulosic properties, which may enable its use as a raw material for particleboard production. Therefore, the objective of this study was to evaluate the use of soybean pods in particleboard production. For particleboard manufacture, wood of the hybrid Eucalyptus urophylla and Eucalyptus grandis was used, added with soybean pods, at proportions of 0%, 25%, 50%, 75% and 100%. For particleboard evaluation, a completely randomized design was used, with five treatments and three replicates, using linear regression and the Scott-Knott test at 5% significance for comparison among the different treatments. The properties apparent density, compaction ratio, water absorption after 2 and 24 hours, thickness swelling after 2 and 24 hours in water immersion, internal bonding, modulus of rupture and modulus of elasticity in bending properties were evaluated. The ratio soybean pod waste and eucalyptus particles in the panels led to an increase in water absorption values and thickness swelling, in addition to a decrease in mechanical properties. The production of panels with approximately 23% soybean pods is feasible.

scholarly journals Towards By-Product Utilisation of Pea Hulls: Isolation and Quantification of Galacturonic Acid

Foods ◽  
2018 ◽  
Vol 7 (12) ◽  
pp. 203 ◽  
Author(s):  
Friederike Gutöhrlein ◽  
Stephan Drusch ◽  
Sebastian Schalow
Keyword(s):  
Galacturonic Acid ◽  
Ethylenediaminetetraacetic Acid ◽  
Raw Materials ◽  
Enzymatic Digestion ◽  
Raw Material ◽  
Trifluoracetic Acid ◽  
Complete Digestion ◽  
Digestion Methods ◽  
Fibre Matrix ◽  
By Products

In order to evaluate by-products from food processing as alternative raw materials for pectin extraction, their amount of galacturonic acid (GalA) has to be analysed as a marker for pectin content. In the present study, significant differences in GalA release using different digestion methods are shown for pea hulls, as an example of by-products with a high content of cellulose. Complete digestion of the fibre matrix was assumed for Saeman hydrolysis as a reference protocol. Significantly lower GalA release was achieved by a treatment with trifluoracetic acid (TFA). An alternative treatment with ethylenediaminetetraacetic acid (EDTA) at pH 11 followed by an enzymatic digestion at pH 4.5 using a combination of polygalacturonase (Vegazyme M) and cellulase (Celluclast 1.5L) resulted in a similar release of GalA compared to Seaman hydolysis. Pea hull samples, analysed by this alternative protocol, showed on average a GalA content of 11.2%. Therefore, pea hulls may serve as new raw material for pectin extraction.

scholarly journals COMPOSITION, PROPERTIES AND RECYCLING OF VEGETATIVE POPLAR AFTER REMOVAL OF EXTRAC-TIVES. REPORT 3. OBTAINING BIOIOGICAL PRODUCTS BASED ON FUNGI OF THE GENUS TRIGHODERMA

2020 ◽  
pp. 415-423
Author(s):  
Elena Vladimirovna Isaeva ◽  
Ol'ga Olegovna Mamaeva ◽  
Tat'yana Vasil'yevna Ryazanova
Keyword(s):  
Plant Growth ◽  
Solid Phase ◽  
Liquid Waste ◽  
Raw Material ◽  
High Yield ◽  
Mycelial Fungi ◽  
Biological Product ◽  
Vegetative Part ◽  
Trichoderma Fungi ◽  
Composition Properties

The purpose of this work was to assess the suitability of solid and liquid waste generated during processing of the vegetative part of poplar as substrates for biochemical processing in order to obtain biologics for various purposes. For the study, we used post-extraction residues, as well as a cubic liquid formed after distilling essential oils and extracting alcohol-soluble substances from the vegetative part of the balsamic poplar (Populus balzamifera L.). Siberian strains of fungi of the genus Trichoderma used as a biodestructor. Studies have shown that the vegetative part of poplar and its individual elements are an available substrate for the growth of mycelial fungi. The high yield of spores (4.5×109 spor/g) and the formation of humic substances (11%) used as plant growth stimulators during solid-phase cultivation of the MG-97 strain of Trichoderma fungi gives grounds to use the vegetative part of poplar as a technological raw material for obtaining a biological product of the "Trichodermin" type or soil humification. Depending on the purpose of the preparations, the duration of cultivation can vary: for obtaining agricultural biologics up to 15 days, more – for soil humification. The inclusion of a cubic liquid at the stage of substrate humidification allows to obtain a biological product with a higher spore titer (5×109 spor/g), makes it possible to close the water consumption cycle and make the technology of processing the vegetative part of poplar waste-free.

scholarly journals Effect of hydrothermal pretreatment of corn stover with pH adjustment on properties of pulp and hydrolysate

BioResources ◽  
2020 ◽  
Vol 15 (3) ◽  
pp. 6826-6839
Author(s):  
Junjun Kong ◽  
Ling Zhang ◽  
Ziyi Niu ◽  
Rina Wu ◽  
Gaosheng Wang
Keyword(s):  
Sodium Hydroxide ◽  
Corn Stover ◽  
Ph Value ◽  
Major Product ◽  
Hydrothermal Pretreatment ◽  
Raw Material ◽  
High Yield ◽  
Pulp Yield ◽  
Industrial Utilization ◽  
The Relationship

In view of environmental and economic issues, co-production technology with pulp as the major product is an important developmental direction in biorefinery. In this paper, high-yield pulp was prepared by hydrothermal pretreatment with controlled pH and subsequent mechanical refining using corn stover as raw material. By adding acetic acid or sodium hydroxide, the properties of the hydrolysate and the pulp were altered. Reducing the pH during hydrothermal pretreatment resulted in more cellulose and hemicellulose being released, while less lignin was released. Increased pH led to more lignin being released, while dissolution of carbohydrates did not change significantly. A maximum pulp yield at pH 5.84 of hydrolysate was obtained when 3.0% sodium hydroxide was used. The strength of pulp is highly related to the removal of lignin during hydrothermal pretreatment. The relationship between pH value in hydrothermal pretreatment and the physical properties of the pulp was established and could be further used for prediction and as guidance for process control. Moreover, the results could be used to develop technologies for industrial utilization of agricultural straw to co-generate fiber and other bio-based products.

scholarly journals The study of patterns of influence of alkali treatment on properties of organosolvent cellulose from straw of rice

2018 ◽  
Author(s):  
А.В. Вураско ◽  
Е.И. Симонова ◽  
А.Р. Минакова ◽  
Д.Д. Манойлович
Keyword(s):  
Metal Ions ◽  
Rice Straw ◽  
Lignin Content ◽  
Alkali Treatment ◽  
Alkaline Treatment ◽  
Raw Material ◽  
High Yield ◽  
Color Determination ◽  
Visual Color

Получение доступных сорбентов на основе природных материалов, для визуального колористического определения содержания ионов металлов в загрязненных природных и сточных водах является актуальным направлением исследований. Сорбенты на основе технической целлюлозы удовлетворяют этим требованиям. В работе для получения технической целлюлозы предложено использовать биомассу соломы риса. Для удаления из соломы риса минерального компонента при проведении окислительно-органосольвентной варки используют стадию щелочной обработки, которая приводит к деструкции полисахаридов, снижая выход технической целлюлозы. В связи с этим целью работы является изучение закономерностей проведения щелочной обработки соломы риса для максимального сохранения высокого выхода технической целлюлозы, извлечения минеральной части и возможности применения данной целлюлозы в качестве колористического сорбента. С учетом предварительных исследований найдены оптимальные значения технологических факторов, обеспечивающих высокий выход волокнистого материала из соломы риса при минимальном содержании в нем минеральных компонентов. Последующая органосольвентная варка позволяет получить техническую целлюлозу с выходом – 48,8% от абсолютно сухого сырья (а.с.с), зольностью 0,05% от а.с.с., содержанием лигнина 2,5% от а.с.с., удовлетворительными прочностными характеристиками, высокими сорбционными свойствами, необходимой белизной и рН водной вытяжки. Выявлено, что техническая целлюлоза из соломы риса содержит металлы, накопленные биомассой за вегетативный период. Щелочная обработка и окислительно-органосольвентная делигнификация в большинстве случаев приводят к снижению концентрации металлов в технической целлюлозе. Исключение составляют алюминий, железо и свинец, содержание которых в технической целлюлозе увеличивается. Таким образом, целлюлоза, полученная в оптимальных условиях щелочной обработки и последующей окислительно-органосольвентной варки из соломы риса, с учетом содержащихся в ней металлов, пригодна для использования в качестве сорбента для визуального колористического определения содержания ионов металлов в загрязненных природных и сточных водах. Receive available sorbents based on natural materials for visual color determination of the content of metal ions in contaminated natural and waste waters is a topical area of research. Sorbents on the basis of technical cellulose satisfy these requirements. In the process of obtaining technical cellulose is proposed to use biomass straw rice. Removal of straw rice mineral component when carrying out the oxidation-organosolvent use the cooking stage alkali treatment, which leads to degradation of polysaccharides, reducing the output of technical cellulose. In this regard, the aim of this work is to study the regularities of the alkaline treatment of rice straw for maximum preservation of the high output technical cellulose, extracting the mineral and the possibility of using the cellulose as the colour of the sorbent. Taking into account the preliminary studies, optimal conditions of technological factors were found ensuring a high yield of fibrous material from rice straw with a minimum content of mineral components in it. Subsequent organosolvent pulping yields technical pulp with a yield of 48.8% bone dry raw material (BDRM), an mineral ash content of 0.05% of BDRM, a lignin content of 2.5% of BDRM, satisfactory strength properties, high sorption properties, the necessary whiteness and pH of aqueous extract. It is revealed that the technical cellulose from straw of rice contains metals accumulated biomass during the vegetation period. Alkaline treatment and oxidative-organosolvent the delignification in most cases leads to a decrease of metal concentrations in pulp technical. With the exception of aluminum, iron and lead, the content of which is technical cellulose increases. Thus, cellulose obtained in optimum conditions of alkaline treatment and subsequent oxidation-organosolvent pulping of straw of rice, taking into account the contained metals suitable for use as a sorbent for visual color determination of the content of metal ions in polluted natural and sewage waters.

scholarly journals Actinobacteria challenge the paradigm: A unique protein architecture for a well-known, central metabolic complex

2021 ◽  
Vol 118 (48) ◽  
pp. e2112107118
Author(s):  
Eduardo M. Bruch ◽  
Pierre Vilela ◽  
Lu Yang ◽  
Alexandra Boyko ◽  
Norik Lexa-Sapart ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Metabolic Engineering ◽  
High Molecular Weight ◽  
Protein Oligomerization ◽  
Central Metabolism ◽  
Hollow Core ◽  
Protein Architecture ◽  
Unique Protein ◽  
Gene Coding

α-oxoacid dehydrogenase complexes are large, tripartite enzymatic machineries carrying out key reactions in central metabolism. Extremely conserved across the tree of life, they have been, so far, all considered to be structured around a high–molecular weight hollow core, consisting of up to 60 subunits of the acyltransferase component. We provide here evidence that Actinobacteria break the rule by possessing an acetyltranferase component reduced to its minimally active, trimeric unit, characterized by a unique C-terminal helix bearing an actinobacterial specific insertion that precludes larger protein oligomerization. This particular feature, together with the presence of an odhA gene coding for both the decarboxylase and the acyltransferase domains on the same polypetide, is spread over Actinobacteria and reflects the association of PDH and ODH into a single physical complex. Considering the central role of the pyruvate and 2-oxoglutarate nodes in central metabolism, our findings pave the way to both therapeutic and metabolic engineering applications.

scholarly journals ANTIFUNGAL AND ANTIBACTERIAL ACTIVITY OF ALOE VERA PLANT EXTRACT

2020 ◽  
Vol 2020 (1) ◽  
Author(s):  
P Danish ◽  
Q Ali ◽  
MM Hafeez ◽  
A Malik
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Aspergillus Niger ◽  
Bacillus Megaterium ◽  
Aloe Vera ◽  
Water Soluble ◽  
Root Extract ◽  
Bacterial Strains ◽  
Zone Of Inhibition ◽  
Fungal Strains

Aloe vera is a well-known medicinal plant used in many therapeutic purposes. Naturally it is composed of many useful compounds that have ability to use for treatment of many diseases. The active compounds reported in this plant are saponins, sugar, enzymes, vitamins, aloesin, aloeemodin, aloin, acemannan aloemannan, aloeride, methylchromones, flavonoids, naftoquinones, sterols, minerals, anthraquinones, amino acids, lignin and salicylic acid and other different compounds including fat-soluble and water-soluble vitamins, enzymes, minerals, simple/complex sugars, organic acid and phenolic compounds. In this study aloe vera is used for antibacterial and antifulgal activity against different strains of bacteria and pathogenic fungal strains. Ethanol extract of Aloe vera leaves and roots is applied on these bacterial and fungal strains in different concentrations (15, 20, 25, 30µl). Bacillus cereus, Bacillus subtitis, Bacillus megaterium, Streptococcus pyogenes, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Acinetobacter baumannii, and some other bacterial strains are used for this study. Escherichia coli and Agrobacterium tumefacins shows zone of inhibition around 18mm which consider as good result. Bacillus subtitis and Bacillus megaterium also shows good result around 16mm. Proteus mirabilis and Pseudomonas aeruginosa shows minimum zone of inhibition which is around 11mm. among all used fungal strains (fuserium oxysporum, Candida albicans, Aspergillus fumigatus, Aspergillus niger) fuserium oxysporum and Aspergillus niger shows excellent results around 19mm both against root extract and leaves extract.

scholarly journals A Novel Inulin-Mediated Ethanol Precipitation Method for Separating Endo-Inulinase From Inulinases for Inulooligosaccharides Production From Inulin

2021 ◽  
Vol 9 ◽  
Author(s):  
Xin Li ◽  
Qiannan Zhang ◽  
Wei Wang ◽  
Shang-Tian Yang
Keyword(s):  
Enzymatic Hydrolysis ◽  
Aspergillus Niger ◽  
Functional Food ◽  
Degree Of Polymerization ◽  
Precipitation Method ◽  
High Yield ◽  
Process Conditions ◽  
Food Ingredients ◽  
Ethanol Precipitation ◽  
Novel Method

Inulin is a kind of polysaccharide that can be obtained various biomass. Inulooligosaccharides (IOS), a kind of oligosaccharides that can be obtained from inulin by enzymatic hydrolysis using inulinases, have been regarded as the functional food ingredients. Commercially available inulinases produced by natural Aspergillus niger contained both endo- and exo-inulinase activities. For IOS production from inulin, it is desirable to use only endo-inulinase as exo-inulinase would produce mainly the monosacchairde fructose from inulin. In the present study, a simple inulin-mediated ethanol precipitation method was developed to separate endo- and exo-inulinases present in natural inulinases. IOS production from inulin using the enriched endo-inulinase was then optimized in process conditions including pH and temperature, achieving a high yield of ∼94%. The resultant IOS products had a degree of polymerization ranging from 2 to 7. The study demonstrated a novel method for obtaining partially purified or enriched endo-inulinase for IOS production from inulin in an efficient process.

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