N-glucosylation in Corynebacterium glutamicum with YdhE from Bacillus lichenformis

Obed Jackson Amoah,Hue Thi Nguyen,Su Yeong Ma,Jae Kyung Sohng 한국당과학회 2022 한국당과학회 학술대회 Vol.2022 No.07

A system was developed to successfully biosynthesize glucoside derivatives of therapeutic and relevant N-linked compounds in the generally regarded as safe (GRAS) Corynebacterium glutamicum. Using glucose, as the sole carbon source, YdhE, which is a promiscuous glycosyltransferase from Bacillus lichenformis and has been introduced in the Corynebacterium glutamicum cell factory system, was able to biosynthesize most of the N-linked compounds to their rare glucosides. Optimal conditions such as IPTG concentrations and induction time, Temperature, Substrate and glucose concentration, and Production time on the In Vivo conversion were successfully developed. This yielded almost 85% of glucosylated butyl-4-aminobenzoate glucoside after only 10 hours post substrate induction. The developed system uses recombinant Corynebacterium glutamicum to achieve In Vivo glucosylation using cheap glucose as the main source of UDP-sugar moieties. Hence making it feasible for industrial-scale biosynthesis of glucoside derivatives by bypassing the demand and use of the more expensive UDP-glucose cofactor that is used in most work that involves glucosylation.

Study of Salting Effect of Inorganic Salts on Nano- and Giant Polymersomes

Obed Andres Solis-Gonzalez,Christopher Chi Wai Tse,Patrick J. Smith,J. Patrick A. Fairclough 한국고분자학회 2022 Macromolecular Research Vol.30 No.9

The salting effect, of kosmotropic and chaotropic salts, on nanoscale and giant-poly(ethylene oxide)16-block-poly(butylene oxide)22 polymersomes was studied. Nanovesicles were studied by dynamic light scattering and transmission electron microscopy and their aggregates (i.e., gel-like structures) by optical microscopy. Giant polymersomes were formed using drop-on-demand inkjet printing and subsequently observed using an optical microscope. The kosmotropic salts were found to strongly influence both vesicle aggregation and giant vesicle (above 3 μm) formation at high salt concentrations (i.e., ~0.5M for nanovesicle aggregation and 0.23 M for giant polymersomes) where the salting effect dominates. Chaotropic salts have very little effect in both systems. The ionic specificity effect essentially determined the outcome of experiments since the type of anion provides different ion/water/ poly(ethylene oxide) interactions and different osmotic stress values, which can be considered the main driving forces and lead the effects observed in experiments (nanovesicle aggregate experiments and abundant giant vesicle formation experiments). The applications of the present work may be lead to better methodologies to produce gel scaffolds for biomaterials or giant unilamellar polymersomes.

Assessment of performance of Lévy flight particle swarm optimization in the estimation of heat source

Obed Cortés-Aburto,José-Alfredo Hernández-Pérez,Rafael Rojas-Rodríguez 대한기계학회 2018 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.32 No.8

We performed a performance assessment of a recently developed method: Lévy flight particle swarm optimization. This method, which was developed for optimization problems, has shown good results. There is not an application to inverse problems. Now, it is applied for inverse heat transfer, and results are good enough. In particular, a parameter called “limit” is analyzed for different values (from 10 to 150). It shows that performance of the method for estimating parameters in inverse problems is affected by this parameter. When limit reaches a value of 80, ordinary least squares norm and consuming time begin to exhibit better results.

Severe acute alcoholic hepatitis and liver transplant: A never-ending mournful story

Aiman Obed,Abdalla Bashir,Steffen Stern,Anwar Jarrad 대한간학회 2018 Clinical and Molecular Hepatology(대한간학회지) Vol.24 No.4

Severe acute alcoholic liver disease (SAAH) unresponsive to medical therapy shows one-year-mortality rates of up to 90%. Most transplant centers request six months of alcohol abstinence prior to transplantation, the so-called “6-month rule.” This regulation is not based on strong evidence, repeatedly making it a topic of controversial debates. The majority of patients with SAAH will die before fulfilling the 6-month rule. Therefore, liver transplantation (LT) protocols are becoming more flexible towards the rigid abstinence regulation, especially concerning SAAH patients. We conducted a literature review regarding LT in SAAH and its outcomes, including post-transplant mortality and recidivism. We studied available data on PubMed from 2011 and onwards whilst including articles dealing with genetic components, medical therapy and historic snapshots of alcoholism. Emerging studies recommend LT in SAAH not responding to medical therapies even without realizing the required abstinence period, since the majority of these patients would die within 6 months. SAAH without response to medical therapy has one-year-mortality rates of up to 90%. The 6-month rule is not based on strong evidence and is repeatedly a topic of controversial debates. There is genetic linkage to alcoholism and medical therapy is not as effective as estimated, yet. The 6-months-regulation has not shown to evidently decrease the risk of recidivism post-LT, which is a lifesaving treatment in SAAH patients. Insisting on rigid sobriety rules results in excluding patients with a low risk of recidivism from being transplanted. Moreover, the genetic linkage of alcoholism must be recognized.

CV Driven Resyllabification of Personal Names in Ẹdo

Osaigbovo Obed Evbuomwan,Veronica EdamweEdobor-Uzamere 세종대학교 언어연구소 2022 Journal of Universal Language Vol.23 No.2

Nouns in the Ẹdo language have been analysed as obligatorily beginning with a vowel. This paper examines personal names as one instance in which that previously conclusive assumption is violated. The synchronic data analysed in this study show that personal names are freely transformed in such a way that they are used with word initial consonants. The study considers this phenomenon as a resyllabification process that seeks to modify personal names to a CVCV syllable pattern. The study analysed personal names that were collected from Ẹdo speakers across the three local government areas that make up Benin city, the capital of Edo state, Nigeria. The study relies on the principles of the CV-phonology model that began in Clements & Keyser and finds that many Ẹdo personal names are functional with or without the word-initial vowels, a re-syllabified name may become meaningless, have adjusted meaning or retain its original meaning. The paper concludes that resyllabification in multi-syllabic personal names is gradual and the overall goal is to reduce them to CVCV syllable patterns.

Phytomanagement of Biosolids-Amended Soil

Juergen Esperschuetz,Obed Lense,Nicholas Dickinson,Craig Anderson,Simon Bulman,Rainer Hofmann,Dharini Paramashivam,Nimlesh Balaine,Timothy Clough,Brett Robinson 한국토양비료학회 2014 한국토양비료학회 학술발표회 초록집 Vol.2014 No.6

Biosynthesis of fucosyllactose in engineered Corynebacterium glutamicum

Hue Thi Nguyen,Obed Jackson Amoah,Su Yeong Ma,Jae Kyung Sohng 한국당과학회 2022 한국당과학회 학술대회 Vol.2022 No.07

Human milk oligosaccharides (HMOs) have been proven to be a key ingredient found in breast milk and beneficial to infant health. Structurally, the fucose-containing oligosaccharides are major components, with a proportion of approximately 50–80% in the HMOs. In particular, 2-fucosyllactose (2’-FL) and 3-fucosyllactose (3-FL) are 2 major components of the abundant HMO component. Importantly, 2’-FL is approved for use in infant formula for improving probiotic functions by the FDA of the USA and the European Food Safety Authority, while 3-FL can be used as a prebiotic to improve the growth of beneficial microorganisms. Over the last decade, various approaches have been conducted for fucosyllactose (FL) production, including chemical synthesis, enzymatic conversion, and microbial fermentation. Most studies were performed in Escherichia coli due to the simple culture conditions and availability of various genetic tools. Besides E. coli, Bacillus subtilis and Saccharomyces cerevisiae have also been selected as the hosts for the production of FL due to their generally regarded safe (GRAS) status. As a type of GRAS strain, Corynebacterium glutamicum has been widely used in the biosynthesis of food-grade, high-value-added products, including lysine, glutamic acid, violacein and resveratrol. In this study, the biosynthetic enzymes of FL were condon-optimized and heterologously expressed in engineered C. glutamicum for the production of FL. The trace amount production of FL was confirmed by TLC, HPLC in this study.

Predictive capability of response surface methodology and cybernetic models for cyanogenic simultaneous nitrification and aerobic denitrification facilitated by cyanide-resistant bacteria

Ncumisa Mpongwana,Seteno Karabo Obed Ntwampe,Lovasoa Christine Razanamahand,Boredi Silas Chidi,Elizabeth Ife Omodanisi 대한환경공학회 2021 Environmental Engineering Research Vol.26 No.6

Free cyanide (CN<SUP>-</SUP>) is a threat to metabolic functions of the microbial population used for the treatment of wastewater, particularly, total nitrogen removal (TN) consortia which gets inhibited by CN<SUP>-</SUP> in wastewater treatment plants (WWTPs). Many other methods are used to treat CN<SUP>-</SUP> prior to the TN removal stages; however, these methods increase the operational cost of the WWTPs. The capability of a microbial population to use multiple substrates is critical in WWTP and in eliminating inhibition associated with CN<SUP>-</SUP>. Previously, cyanide resistant bacteria were used to eliminate the inhibitory effect of CN<SUP>-</SUP> towards simultaneous nitrification and aerobic denitrification (SNaD). However, a study to predict the degradation efficiency of the microorganism was required. In this study, response surface methodology (RSM) and cybernetic models were used to predict and optimize SNaD performance for TN removal under CN<SUP>-</SUP> conditions. Physiological parameters influencing the SNaD were pH 6.5 and 36.5℃, with TN and CN<SUP>-</SUP> degradation efficiency of 78.6 and 80.2%, respectively. These results show a complete elimination of the CN<SUP>-</SUP>inhibitory effect towards SNaD and show the prediction ability of both RSM and the cybernetic models used. These results exhibited a promising solution in the control, management, and optimization of SNaD.

Predictive capability of response surface methodology and cybernetic models for cyanogenic simultaneous nitrification and aerobic denitrification facilitated by cyanide-resistant bacteria

Ncumisa Mpongwana,Seteno Karabo Obed Ntwampe,Lovasoa Christine Razanamahandry,Boredi Silas Chidi,Elizabeth Ife Omodanisi 대한환경공학회 2021 Environmental Engineering Research Vol.26 No.6

Free cyanide (CN−) is a threat to metabolic functions of the microbial population used for the treatment of wastewater, particularly, total nitrogen removal (TN) consortia which gets inhibited by CN− in wastewater treatment plants (WWTPs). Many other methods are used to treat CN− prior to the TN removal stages; however, these methods increase the operational cost of the WWTPs. The capability of a microbial population to use multiple substrates is critical in WWTP and in eliminating inhibition associated with CN−. Previously, cyanide resistant bacteria were used to eliminate the inhibitory effect of CN− towards simultaneous nitrification and aerobic denitrification (SNaD). However, a study to predict the degradation efficiency of the microorganism was required. In this study, response surface methodology (RSM) and cybernetic models were used to predict and optimize SNaD performance for TN removal under CN− conditions. Physiological parameters influencing the SNaD were pH 6.5 and 36.5°C, with TN and CN− degradation efficiency of 78.6 and 80.2%, respectively. These results show a complete elimination of the CN− inhibitory effect towards SNaD and show the prediction ability of both RSM and the cybernetic models used. These results exhibited a promising solution in the control, management, and optimization of SNaD.

Performance of Fusarium oxysporum EKT01/02 isolate in cyanide biodegradation system

Enoch Akinbiyi Akinpelu,Adewole Tomiwa Adetunji,Seteno Karabo Obed Ntwampe,Felix Nchu,Lukhanyo Mekuto 대한환경공학회 2018 Environmental Engineering Research Vol.23 No.2

This study reports a cyanide resistant and/or tolerant fungus, isolated from the rhizosphere of Zea mays contaminated with cyanide-based pesticides. The isolate was characterised using molecular biology. The effect of free cyanide and heavy metals on the growth of isolate in a synthetic gold mine wastewater was examined. The molecular analyses identified the isolate as Fusarium oxysporum EKT01/02 (KU985430/KU985431). The isolate had a free cyanide degradation efficiency of 77.6%. The results indicated greater growth impairment in culture containing Arsenic (optical density 1.28 and 1.458) and cyanide (optical density 1.315 and 1.385). Higher growth was observed in all cultures supplemented with extracellular polymeric substance. This study showed that the isolate possesses wide substrate utilisation mechanism that could be deployed in environmental engineering applications.