scholarly journals Production and Escalation of L-Lysine via Bacterial Fermentation Utilizing Streptococcus Sp

Author(s):  
Shanzay Saleem ◽  
Mehreen Sarfraz ◽  
Zohaib Ahmad ◽  
Nuzhat Munawar ◽  
Zeeshan Rehman ◽  
...  

Abstract Background and AimsThe importance of L-lysine as an essential amino acid in the nutrition of human beings has made it desirable supplement of the diet in recent years. It can be produced in different ways among them fermentation is the most economical and practical means of producing lysine. In this method low temperature, low pressure and low-cost carbon sources are used and a biological form of lysine (L-lysine) is produced. MethodsIn the present study, the production of L-lysine was achieved through fermentation developed from locally isolated bacterial strains. In total, twenty-nine (29) bacterial strains were isolated and tested using paper chromatographic technique. Six different parameters for optimization were scrutinized for improved bacterial growth and significant yield of lysine was obtained using selected strains.Key ResultsFor Streptococcus sp. molasses media with vitamins (w) formed 24.4 g/L, 40º C generated 24.4 g/L, addition of 1mM solution of metal ion (Mg) yielded 20.4 g/L, pH 6.5 delivered 6 g/L, fermentation period of 96 hours engendered 24.4 g/L, and 0.3 mL of inoculum results in 9.2 g/L of lysine. ConclusionsLaboratory scale production of L-lysine was carried out using 1 L Erlenmeyer flask. For Streptococcus sp. 23.4 g/L of lysine was produced after optimized conditions.

2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
Tene Hippolyte Mouafo ◽  
Augustin Mbawala ◽  
Robert Ndjouenkeu

The potential of three indigenous bacterial strains (Lactobacillus delbrueckiiN2,Lactobacillus cellobiosusTM1, andLactobacillus plantarumG88) for the production of biosurfactants using sugar cane molasses or glycerol as substrates was investigated through emulsifying, surface tension, and antimicrobial activities. The different biosurfactants produced with molasses as substrate exhibited high surface tension reduction from 72 mN/m to values ranged from 47.50 ± 1.78 to 41.90 ± 0.79 mN/m and high emulsification index ranging from 49.89 ± 5.28 to 81.00 ± 1.14%. Whatever theLactobacillusstrain or the substrate used, the biosurfactants produced showed antimicrobial activities againstCandida albicansLV1, some pathogenic and/or spoilage Gram-positive and Gram-negative bacteria. The yields of biosurfactants with molasses (2.43 ± 0.09 to 3.03 ± 0.09 g/L) or glycerol (2.32 ± 0.19 to 2.82 ± 0.05 g/L) were significantly (p<0.05) high compared to those obtained with MRS broth as substrate (0.30 ± 0.02 to 0.51 ± 0.09 g/L). Preliminary characterization of crude biosurfactants reveals that they are mainly glycoproteins and glycolipids with molasses and glycerol as substrate, respectively. Therefore, sugar cane molasses or glycerol can effectively be used byLactobacillusstrains as low-cost substrates to increase their biosurfactants production.


2020 ◽  
Vol 09 ◽  
Author(s):  
Felipe Sanches Edaes ◽  
Cleide Barbieri de Souza

Background: Plastic materials are ubiquitous and, despite the great benefits and advantages that the materials provides to human beings and to society, its harmful effects are remarkable, since plastics’ ingestion is harmful and can occur through microplastics and their by-products (BPA and DEHP), and can trigger health problems, also, the material decomposition time is great and, consequently, plastic waste accumulates in the environment, representing a major problem to fauna and flora. Objectives: To develop a review study of conventional plastics’ negative aspect in human and environmental life, as well as to study the existing biological and molecular strategies for the production of biodegradable plastics, making a comparison of their advantages over conventional plastics, in favor of socio-environmental welfare. Methods: In this review, articles published in the last 20 years related to different aspects of conventional plastics and biodegradable plastics were accurately analyzed and reviewed. The subjects addressed ranged from conventional plastics and the problems related to their large-scale production, as well as biodegradable plastics, their advantages and the most recent advances in the development of production methods and improvement of these biopolymers, being extensively reviewed and discussed concisely. Results: The present study demonstrated that, among the biopolymers discussed, thermoplastic starch (TPS) is one of the most promising due to its low cost, being one of the best materials to provide a viable alternative in the search for biodegradable plastics, while polylactic acid (PLA) presents the greatest potential for future medical applications due to its unique physicochemical properties and the possibility of being used in 3D printing techniques, and polyhydroxyalkanoates (PHAs) have the greatest commercial potential in replacing fossil fuel-based plastics because of their similar properties to conventional plastics and because they are synthesized by microorganisms from renewable carbon sources. Conclusions: This study demonstrated the various harmful effects that the large-scale use and improper disposal of conventional plastic materials generates to the environment and human health, and proposed an alternative to this problem, the biodegradable plastics. Although this study presented three promising biodegradable plastics (TPS, PLA and PHAs), as well as described their production methods, there are currently no viable biodegradable plastic polymers that can be used for the total replacement of conventional plastics, especially from an economic perspective. However, in the future, modifications in the production methods and chemical structures of these polymers will allow the replacement of conventional plastics by biodegradable plastics, as well as a more extensive application of these biopolymers.


2020 ◽  
Vol 36 (2) ◽  
pp. 86-98
Author(s):  
A.A. Sergeeva ◽  
G.V. Ovechkina ◽  
A.Yu. Maksimov

Bacterial strains capable of degradation of 0.8-15.8 g/1 pyridine hydrochloride have been isolated from activated sludge of municipal biological treatment plants in Perm (BOS) and local treatment facilities of the LUKOIL-Permnefteorgsintez enterprise (PNOS). The strains were identified as Achromobacter pulmonis and Burkholderia dolosa. The optimal pyridine concentration for the growth of the isolated strains was 4.0 g/1. The pyridine degradation during the A. pulmonis PNOS and B. dolosa BOS cultivation on a medium with ammonium chloride and glucose and without additional nitrogen or carbon sources was studied. It was shown that the strains are able to accumulate biomass in a medium with pyridine as the sole carbon and nitrogen source; the addition of glucose to the medium (1 g/L) accelerated the pyridine degradation by A. pulmonis PNOS, but inhibited the process carried out by B. dolosa BOS. B. dolosa BOS and A. pulmonis PNOS biofilms efficiently utilized pyridine during growth on basalt and carbon fibers; the highest rate of pyridine utilization (1.8 g /(L day)) was observed in A. pulmonis PNOS biofilms on basalt fibers. pyridine, biodegradation, activated sludge, biofilms, Achromobacter pulmonis, Burkholderia dolosa The authors grateful to Dr. I.I. Tchaikovsky, Head of the Laboratory of Geology of Mineral Deposits of the Mining Institute, a branch of the Perm Federal Research Center, for help with electron microscopy of the samples. This work was carried out as part of a state assignment on the topic « Study of the Functional and Species Diversity of Microorganisms Useful for Ecocenoses and Human Practical Activity», registration number R&D AAAA-A19-119112290008-4.


2020 ◽  
Vol 16 ◽  
Author(s):  
Asma S. Algebaly ◽  
Afrah E. Mohammed ◽  
Mudawi M. Elobeid

Introduction: Fabrication of iron nanoparticles (FeNPs) has recently gained a great concern for their varied applications in remediation technologies of the environment. Objective: The current study aimed to fabricate iron nanoparticles by green technology approach using different plant sources, Azadirachta indica leaf and Calligonum comosum root following two extraction methods. Methods: Currently, a mixture of FeCl2 and FeCl3 was used to react with the plant extracts which are considered as reducing and stabilizing agents for the generation of FeNPs in one step. Different techniques were used for FeNPs identification. Results: Immediately after mixing of the two reaction components, the color changed to dark brown as an indication of safe conversion of Fe ions to FeNPs, that later confirmed by zeta sizer, transmission electron microscopy (TEM) and scanning electron microscopy (SEM). FeNPs fabricated by C. comosum showed smaller size when compared by those fabricated by A. indica. Using both plant sources, FeNPs fabricated by the aqueous extract had smaller size in relation to those fabricated by ethanolic extract. Furthermore, antibacterial ability against two bacterial strains was approved. Conclusion: The current results indicated that, at room temperature plant extracts fabricated Fe ion to Fe nanoparticles, suggesting its probable usage for large scale production as well as its suitability against bacteria. It could also be recommended for antibiotic resistant bacteria.


2021 ◽  
Vol 3 (6) ◽  
Author(s):  
Yixin Liu ◽  
Zhen Li ◽  
Yutong Feng ◽  
Juming Yao

AbstractConductive yarn is an important component and connector of electronic and intelligent textiles, and with the development of high-performance and low-cost conductive yarns, it has attracted more attention. Herein, a simple, scalable sizing process was introduced to prepare the graphene-coated conductive cotton yarns. The electron conductive mechanism of fibers and yarns were studied by the percolation and binomial distribution theory, respectively. The conductive paths are formed due to the conductive fibers' contact with each other, and the results revealed that the connection probability of the fibers in the yarn (p) is proportional to the square of the fibers filling coefficient (φ) as p ∝ φ2. The calculation formula of the staple spun yarn resistance can be derived from this conclusion and verified by experiments, which further proves the feasibility of produce conductive cotton yarns by sizing process.


2020 ◽  
Vol 9 (1) ◽  
pp. 751-759 ◽  
Author(s):  
Xinxin Lian ◽  
Yuanjiang Lv ◽  
Haoliang Sun ◽  
David Hui ◽  
Guangxin Wang

AbstractAg nanoparticles/Mo–Ag alloy films with different Ag contents were prepared on polyimide by magnetron sputtering. The effects of Ag contents on the microstructure of self-grown Ag nanoparticles/Mo–Ag alloy films were investigated using XRD, FESEM, EDS and TEM. The Ag content plays an important role in the size and number of uniformly distributed Ag nanoparticles spontaneously formed on the Mo–Ag alloy film surface, and the morphology of the self-grown Ag nanoparticles has changed significantly. Additionally, it is worth noting that the Ag nanoparticles/Mo–Ag alloy films covered by a thin Ag film exhibits highly sensitive surface-enhanced Raman scattering (SERS) performance. The electric field distributions were calculated using finite-difference time-domain analysis to further prove that the SERS enhancement of the films is mainly determined by “hot spots” in the interparticle gap between Ag nanoparticles. The detection limit of the Ag film/Ag nanoparticles/Mo–Ag alloy film for Rhodamine 6G probe molecules was 5 × 10−14 mol/L. Therefore, the novel type of the Ag film/Ag nanoparticles/Mo–Ag alloy film can be used as an ideal SERS-active substrate for low-cost and large-scale production.


Author(s):  
Alif Chebbi ◽  
Massimiliano Tazzari ◽  
Cristiana Rizzi ◽  
Franco Hernan Gomez Tovar ◽  
Sara Villa ◽  
...  

Abstract Within the circular economy framework, our study aims to assess the rhamnolipid production from winery and olive oil residues as low-cost carbon sources by nonpathogenic strains. After evaluating various agricultural residues from those two sectors, Burkholderia thailandensis E264 was found to use the raw soluble fraction of nonfermented (white) grape marcs (NF), as the sole carbon and energy source, and simultaneously, reducing the surface tension to around 35 mN/m. Interestingly, this strain showed a rhamnolipid production up to 1070 mg/L (13.37 mg/g of NF), with a higher purity, on those grape marcs, predominately Rha-Rha C14-C14, in MSM medium. On olive oil residues, the rhamnolipid yield of using olive mill pomace (OMP) at 2% (w/v) was around 300 mg/L (15 mg/g of OMP) with a similar CMC of 500 mg/L. To the best of our knowledge, our study indicated for the first time that a nonpathogenic bacterium is able to produce long-chain rhamnolipids in MSM medium supplemented with winery residues, as sole carbon and energy source. Key points • Winery and olive oil residues are used for producing long-chain rhamnolipids (RLs). • Both higher RL yields and purity were obtained on nonfermented grape marcs as substrates. • Long-chain RLs revealed stabilities over a wide range of pH, temperatures, and salinities


Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1786
Author(s):  
Carla Queirós ◽  
Chen Sun ◽  
Ana M. G. Silva ◽  
Baltazar de Castro ◽  
Juan Cabanillas-Gonzalez ◽  
...  

The development of straightforward reproducible methods for the preparation of new photoluminescent coordination polymers (CPs) is an important goal in luminescence and chemical sensing fields. Isophthalic acid derivatives have been reported for a wide range of applications, and in addition to their relatively low cost, have encouraged its use in the preparation of novel lanthanide-based coordination polymers (LnCPs). Considering that the photoluminescent properties of these CPs are highly dependent on the existence of water molecules in the crystal structure, our research efforts are now focused on the preparation of CP with the lowest water content possible, while considering a green chemistry approach. One- and two-dimensional (1D and 2D) LnCPs were prepared from 5-aminoisophthalic acid and Sm3+/Tb3+ using hydrothermal and/or microwave-assisted synthesis. The unprecedented LnCPs were characterized by single-crystal X-ray diffraction (SCRXD), powder X-ray diffraction (PXRD), Fourier transform infrared (FT-IR) spectroscopy and scanning electron microscopy (SEM), and their photoluminescence (PL) properties were studied in the solid state, at room temperature, using the CPs as powders and encapsulated in poly(methyl methacrylate (PMMA) films, envisaging the potential preparation of devices for sensing. The materials revealed interesting PL properties that depend on the dimensionality, metal ion, co-ligand used and water content.


Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1706
Author(s):  
Zacharias Viskadourakis ◽  
Argiri Drymiskianaki ◽  
Vassilis M. Papadakis ◽  
Ioanna Ioannou ◽  
Theodora Kyratsi ◽  
...  

In the current study, polymer-based composites, consisting of Acrylonitrile Butadiene Styrene (ABS) and Bismuth Antimony Telluride (BixSb2−xTe3), were produced using mechanical mixing and hot pressing. These composites were investigated regarding their electrical resistivity and Seebeck coefficient, with respect to Bi doping and BixSb2-xTe3 loading into the composite. Experimental results showed that their thermoelectric performance is comparable—or even superior, in some cases—to reported thermoelectric polymer composites that have been produced using other complex techniques. Consequently, mechanically mixed polymer-based thermoelectric materials could be an efficient method for low-cost and large-scale production of polymer composites for potential thermoelectric applications.


2013 ◽  
Vol 829 ◽  
pp. 386-390 ◽  
Author(s):  
Mehri Imani ◽  
Alimorad Rashidi ◽  
Mojtaba Shariaty-Niassar ◽  
Elahe Sarlak ◽  
Amir Zarghan

Carbon membranes have high adsorption capacitiy with respect to its incredible properties such as unique structural, electronic, optoelectronic, semiconductor, mechanical, chemical and physical. Carbon nanotube (CNT) membranes because of its high permeance have been recently developed.Great attention has been currently paid to the field of fabrication methods capable of producing uniform, well-aligned and monodispersed CNT array. Current research concerns with fabrication of vertically aligned CNT membrane in order to remove heavy metal ion presents in waste water. For this purpose, CNTs are vertically grown up through the holes of anodic aluminium oxide (AAO); as a template, by chemical vapor deposition (CVD) of acetylene gas.In this work a few heavy metals such as Pb (II), Cu (II) and Cd (II) has been examined for checking the perfomance of membrane in aqueous solution. The morphological properties of the aligned CNT membrane were investigated with scanning electron microscopy (SEM). The method has simple technology, low cost, and easy reproduction.


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