scholarly journals Prospective Application of Aspergillus Species: Focus on Enzyme Production Strategies, Advances and Challenges

2022 ◽  
Author(s):  
Mohammadhassan Gholami-Shabani ◽  
Masoomeh Shams-Ghahfarokhi ◽  
Fatemehsadat Jamzivar ◽  
Mehdi Razzaghi-Abyaneh

Fungal enzymes that catalyze different types of biochemical reactions play a significant role in modern industry by improving existing processes. Also, the use of enzymes to replace some traditional toxic chemical or mechanical approaches helps decrease energy demand and environmental pollution. However, enzymes must be able to compete commercially with relatively low-priced traditional approaches. Meeting economical and commercial feasibility criteria depends on a number of enzymatic properties including the specificity to the substrate, stability in industrial enzymatic reaction conditions and catalytic efficiency. Fungi used as an enzyme manufacture host should be appropriate for industrial scale fermentation. Aspergillus species are being developed as one of the best enzyme manufacture factories due to their capability to secrete high quantities of enzymes suitable for industrial applications. The industrial importance of Aspergillus species also includes the progress and commercialization of new products derived from genetically engineered modified strains. Hence, the main aim of this chapter investigation is to analyze the secreted and cellular proteins from Aspergillus species and their application in industries.

2003 ◽  
Vol 69 (4) ◽  
pp. 2110-2115 ◽  
Author(s):  
Ziye Liu ◽  
Yuquan Lu ◽  
Jianbo Zhang ◽  
Keith Pardee ◽  
Peng George Wang

ABSTRACT The frequency of Escherichia coli infection has lead to concerns over pathogenic bacteria in our food supply and a demand for therapeutics. Glycolipids on gut cells serve as receptors for the Shiga-like toxin produced by E. coli. Oligosaccharide moiety analogues of these glycolipids can compete with receptors for the toxin, thus acting as antibacterials. An enzymatic synthesis of the P1 trisaccharide (Galα1,4Galβ1,4GlcNAc), one of the oligosaccharide analogues, was assessed in this study. In the proposed synthetic pathway, UDP-glucose was generated from sucrose with an Anabaena sp. sucrose synthase and then converted with an E. coli UDP-glucose 4-epimerase to UDP-galactose. Two molecules of galactose were linked to N-acetylglucosamine subsequently with a Helicobacter pylori β-l,4-galactosyltransferase and a Neisseria meningitidis α-1,4-galactosyltransferase to produce one molecule of P1 trisaccharide. The four enzymes were coexpressed in a single genetically engineered E. coli strain that was then permeabilized and used to catalyze the enzymatic reaction. P1 trisaccharide was accumulated up to 50 mM (5.4 g in a 200-ml reaction volume), with a 67% yield based on the consumption of N-acetylglucosamine. This study provides an efficient approach for the preparative-scale synthesis of P1 trisaccharide with recombinant bacteria.


2003 ◽  
Vol 69 (8) ◽  
pp. 4438-4447 ◽  
Author(s):  
Jung-Kul Lee ◽  
Bong-Seong Koo ◽  
Sang-Yong Kim ◽  
Hyung-Hwan Hyun

ABSTRACT Mannitol biosynthesis in Candida magnoliae HH-01 (KCCM-10252), a yeast strain that is currently used for the industrial production of mannitol, is catalyzed by mannitol dehydrogenase (MDH) (EC 1.1.1.138). In this study, NAD(P)H-dependent MDH was purified to homogeneity from C. magnoliae HH-01 by ion-exchange chromatography, hydrophobic interaction chromatography, and affinity chromatography. The relative molecular masses of C. magnoliae MDH, as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and size-exclusion chromatography, were 35 and 142 kDa, respectively, indicating that the enzyme is a tetramer. This enzyme catalyzed both fructose reduction and mannitol oxidation. The pH and temperature optima for fructose reduction and mannitol oxidation were 7.5 and 37°C and 10.0 and 40°C, respectively. C. magnoliae MDH showed high substrate specificity and high catalytic efficiency (k cat = 823 s−1, K m = 28.0 mM, and k cat /K m = 29.4 mM−1 s−1) for fructose, which may explain the high mannitol production observed in this strain. Initial velocity and product inhibition studies suggest that the reaction proceeds via a sequential ordered Bi Bi mechanism, and C. magnoliae MDH is specific for transferring the 4-pro-S hydrogen of NADPH, which is typical of a short-chain dehydrogenase reductase (SDR). The internal amino acid sequences of C. magnoliae MDH showed a significant homology with SDRs from various sources, indicating that the C. magnoliae MDH is an NAD(P)H-dependent tetrameric SDR. Although MDHs have been purified and characterized from several other sources, C. magnoliae MDH is distinguished from other MDHs by its high substrate specificity and catalytic efficiency for fructose only, which makes C. magnoliae MDH the ideal choice for industrial applications, including enzymatic synthesis of mannitol and salt-tolerant plants.


Author(s):  
Guo Ruihua ◽  
Duan Dong ◽  
Shaotong Hong ◽  
Yu Zhou ◽  
Fang Wang ◽  
...  

A marine fibrinolytic compound FGFC1 enhancing fibrinolysis was obtained involving in enzymatic kinetic parameters of reciprocal activation system with single chain urokinase type plasminogen activator and plasminogen. FGFC1, a kind of bisindole alkaloid from a metabolite of rare marine fungi Starchbotrys longispora FG216, modulated enzymatic kinetic parameters including fibrinolytic reaction rate and fibrin degradation characteristics. The enzymatic kinetics of fibrinolysis was described based on enzymatic reaction of chromogenic-substrate associated with p-nitroaniline (p-NA). While single chain urokinase-type plasminogen activator (pro-uPA) actived plasminogen, Kcat and kcat/km increased significantly with increase of FGFC1 concentration. Moreover, Kcat and kcat/km exhibited 26.5-fold and 22.8-fold enhanced activity at the concentration of 40 μg•mL−1 of FGFC1, respectively. The results suggested that FGFC1 improved significantly the maximum catalytic efficiency and the total catalytic activity of fibrinolysis base on the reciprocal activation of pro-uPA and plasminogen. Km increased with increasing FGFC1 concentration, which indicated that FGFC1 decreased slightly the affinity activity of pro-uPA and plasminogen versus enzyme substrate. The marine bisindole alkaloid FGFC1 enhanced fibrinolysis which was taken on enzymatic kinetic characteristics.


Author(s):  
Farooq Syed ◽  
Mujeeb Khan ◽  
Mohammed Rafi Shaik ◽  
Mufsir Kuniyil ◽  
M Rafiq Siddiqui ◽  
...  

In this study, we reported the eco-friendly fabrication of Ag2O–MnO2/GRO nanocomposites by the solid-state mixing of separately prepared GRO and Ag2O–MnO2 NPs using ball milling method, a mechanochemical approach. The prepared material was studied for the catalytic effect of GRO in the system for the aerial oxidation of a variety of alcohols. It was found that the (1%)Ag2O–MnO2/(5 wt.%)GRO nanocatalyst demonstrated a high conversion ability (~100%) and excellent selectivity in the presence of O2 as a clean oxidant. The higher catalytic properties of the nanocomposite were attributed to the presence of GRO, which exhibited extraordinary catalytic properties like improved surface area, excellent chemical compatibility, and stability, as well as the introduction of several defects in the obtained nanocomposite that enhance the catalytic performance. The specific activity of 13.3 mmol·g−1·h−1 is obtained for the catalyst i.e. (1%)Ag2O–MnO2/(5 wt.%)GRO, which is reportedly superior to the various other catalysts previously reported in the literature for the same conversion reaction. Our catalytic strategy was highly selective, producing only desired products with no over-oxygenation to carboxylic acids. The merits of our catalytic methodology were: (a) facile process, (b) inexpensive and clean oxidant, (c) no surfactants or nitrogenous bases were required, (d) mild catalytic conditions, (e) cost-effective recoverable catalyst, (f) complete convertibility, (g) full selectivity, (h) rapid process, and (i) applicable to virtually all types of alcohols. So, these highlights made this catalytic strategy to be highly applicable in the industrial applications for manufacturing of carbonyls. To the best of our knowledge, this was the first study of utilizing Ag2O–MnO2/GRO composite as a catalyst for the oxidation of alcohols, highlighting the catalytic efficiency of GRO.


2020 ◽  
Vol 3 (2) ◽  
pp. 91
Author(s):  
Tarık Uçar ◽  
Kubilay Aziz

Industrial attentiveness and demand for natural bioactive compounds are rising continuously, regarding their growing commercial values in nutrition, pharmaceuticals, cosmetics and many other industries. The progress in ultrasound technology has spread the use of ultrasonication on a broad field of application areas, including extraction of bio-materials from plant sources. Ultrasound-assisted extraction is a powerful alternative to conventional techniques, in terms of extracting bio-compounds from variable kinds of matrices, higher efficiency, reduced extraction time, toxic-free operation, lower energy demand, lesser water consumption and better extract quality. Existing research pointed out that the reactor configuration is vital for maximizing the efficacy of extraction process, however basic reactor configurations that were mainly used in the literature may not be feasibly adapted to full-scale industrial applications. In this study, an investigation on possible improvements and modifications to existing reactor designs are discussed, such as detecting the optimum frequency range of ultrasound transmission depending on the material rheology and composition, possible modifications in beam-forming by means of frequency modulation and finally transmitting the waves in combination of different frequencies.


2019 ◽  
Author(s):  
Josef R Bober ◽  
Nikhil Nair

AbstractThere are many enzymes that are relevant for making rare and valuable chemicals that while active, are severely limited by thermodynamic, kinetic, or stability issues (e.g. isomerases, lyases, transglycosidase etc.). In this work, we study an enzymatic reaction system −Lactobacillus sakeiL-arabinose isomerase (LsLAI) for D-galactose to D-tagatose isomerization – that is limited by all three reaction parameters. The enzyme has a low catalytic efficiency for non-natural substrate galactose, has low thermal stability at temperatures > 40 °C, and equilibrium conversion < 50%. After exploring several strategies to overcome these limitations, we finally show that encapsulating the enzyme in a gram-positive bacterium (Lactobacillus plantarum) that is chemically permeabilized can enable reactions at high rates, high conversion, and at high temperatures. The modified whole cell system stabilizes the enzyme, differentially partitions substrate and product across the membrane to shift the equilibrium toward product formation enables rapid transport of substrate and product for fast kinetics. In a batch process, this system enables approximately 50 % conversion in 4 h starting with 300 mM galactose (an average productivity of 37 mM/h), and 85 % conversion in 48 h, which are the highest reported for food-safe mesophilic tagatose synthesis. We suggest that such an approach may be invaluable for other enzymatic processes that are similarly kinetically-, thermodynamically-, and/or stability-limited.


2021 ◽  
Vol 22 (21) ◽  
pp. 11956
Author(s):  
Saadiah A. Abdulmalek ◽  
Kai Li ◽  
Jianhua Wang ◽  
Michael Kidane Ghide ◽  
Yunjun Yan

This article describes the successful synthesis of a novel nanocomposite of superparamagnetic multi-walled nanotubes with a four-arm polyethylene glycol amine polymer (mMWCNTs@4-arm-PEG-NH2). This composite was then employed as a support for the covalent co-immobilization of Rhizopus oryzae and Candida rugosa lipases under appropriate conditions. The co-immobilized lipases (CIL-mMWCNTs@4-arm-PEG-NH2) exhibited maximum specific activity of 99.626U/mg protein, which was 34.5-fold superior to that of free ROL, and its thermal stability was greatly improved. Most significantly, CIL-mMWCNTs@4-arm-PEG-NH2 was used to prepare biodiesel from waste cooking oil under ultrasound conditions, and within 120 min, the biodiesel conversion rate reached 97.64%. This was due to the synergy effect between ROL and CRL and the ultrasound-assisted enzymatic process, resulting in an increased biodiesel yield in a short reaction time. Moreover, after ten reuse cycles, the co-immobilized lipases still retained a biodiesel yield of over 78.55%, exhibiting excellent operational stability that is attractive for practical applications. Consequently, the combined use of a novel designed carrier, the co-immobilized lipases with synergy effect, and the ultrasound-assisted enzymatic reaction exhibited potential prospects for future applications in biodiesel production and various industrial applications.


Catalysts ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 955
Author(s):  
Lingxia Xu ◽  
Jianzhong Sun ◽  
Majjid A. Qaria ◽  
Lu Gao ◽  
Daochen Zhu

Dye decoloring peroxidases (DyPs) were named after their high efficiency to decolorize and degrade a wide range of dyes. DyPs are a type of heme peroxidase and are quite different from known heme peroxidases in terms of amino acid sequences, protein structure, catalytic residues, and physical and chemical properties. DyPs oxidize polycyclic dyes and phenolic compounds. Thus they find high application potentials in dealing with environmental problems. The structure and catalytic characteristics of DyPs of different families from the amino acid sequence, protein structure, and enzymatic properties, and analyzes the high-efficiency degradation ability of some DyPs in dye and lignin degradation, which vary greatly among DyPs classes. In addition, application prospects of DyPs in biomedicine and other fields are also discussed briefly. At the same time, the research strategy based on genetic engineering and synthetic biology in improving the stability and catalytic activity of DyPs are summarized along with the important industrial applications of DyPs and associated challenges. Moreover, according to the current research findings, bringing DyPs to the industrial level may require improving the catalytic efficiency of DyP, increasing production, and enhancing alkali resistance and toxicity.


Author(s):  
Hyeseung Lee ◽  
Dean Ho ◽  
Benjamin Chu ◽  
Karen Kuo ◽  
Carlo Montemagno

We have successfully purified BR from purple membrane of Halobacterium Salinarium and Cox from the genetically engineered plasmid inserted in Rhodobacter Sphaeroides. The activities of the purified enzymes have shown in lipid vesicles as well as in polymer vesicles and planar membranes. Phosphatidylcholine derived lipid vesicles created the most nature like environment for the enzymes. Triblock copolymer membrane was the alternative choice for membrane protein reconstitution since polymers are more durable, ideal for industrial applications and support enzyme activities better. We also demonstrated the backward function of Cox in vitro by changing proton concentration in the surrounding medium. Langmuir-Blodgett method was used to reconstitute the enzymes into the planar lipid or polymer membranes. The enzyme activities of the enzymes in planar membrane system were tested by impedance spectroscopy.


2018 ◽  
Author(s):  
Laura Marvin ◽  
Wynter Paiva ◽  
Nicole Gill ◽  
Marissa A. Morales ◽  
Jeffrey Mark Halpern ◽  
...  

<div>Biological and bioinspired polymer microparticles have broad biomedical and industrial applications, including drug delivery, tissue engineering, surface modification, environmental remediation, imaging, and sensing. Full realization of the potential of biopolymer microparticles will require methods for rigorous characterization of particle sizes, morphologies, and dynamics, so that researchers may correlate particle characteristics with synthesis methods and desired functions. Toward this end, we evaluated biopolymer microparticles using flow imaging microscopy. This technology is widely used in the biopharmaceutical industry but is not yet well-known among the materials community. Our polymer, a genetically engineered elastin-like polypeptide (ELP), self-assembles into micron-scale coacervates. We performed flow imaging of ELP coacervates using two different instruments, one with a lower size limit of approximately 2 microns, the other with a lower size limit of approximately 300 nanometers. We validated flow imaging results by comparison with dynamic light scattering and atomic force microscopy analyses. We explored the effects of various solvent conditions on ELP coacervate size, morphology, and behavior, such as the dispersion of single particles versus aggregates. We found that flow imaging is a superior tool for rapid and thorough particle analysis of ELP coacervates in solution. We anticipate that researchers studying many types of microscale protein or polymer assemblies will be interested in flow imaging as a tool for quantitative, solution-based characterization.<br></div>


Sign in / Sign up

Export Citation Format

Share Document