Mass Spectrometry Reveals Molecular Structure of Polyhydroxyalkanoates Attained by Bioconversion of Oxidized Polypropylene Waste Fragments

This study investigated the molecular structure of the polyhydroxyalkanoate (PHA) produced via a microbiological shake flask experiment utilizing oxidized polypropylene (PP) waste as an additional carbon source. The bacterial strain Cupriavidus necator H16 was selected as it is non-pathogenic, genetically stable, robust, and one of the best known producers of PHA. Making use of PHA oligomers, formed by controlled moderate-temperature degradation induced by carboxylate moieties, by examination of both the parent and fragmentation ions, the ESI-MS/MS analysis revealed the 3-hydroxybutyrate and randomly distributed 3-hydroxyvalerate as well as 3-hydroxyhexanoate repeat units. Thus, the bioconversion of PP solid waste to a value-added product such as PHA tert-polymer was demonstrated.

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Increasing Chitinase Activity of Serratia marcescens PT-6 through Optimization of Medium Composition

SQUALEN Bulletin of Marine and Fisheries Postharvest and Biotechnology ◽

10.15578/squalen.v14i3.414 ◽

2019 ◽

Vol 14 (3) ◽

pp. 113

Author(s):

Akhmad Awaludin Agustiar ◽

Imas Faturrohmah ◽

Bekti Wulan Sari ◽

Nurul Binti Isnaini ◽

Indun Dewi Puspita ◽

...

Keyword(s):

Carbon Source ◽

Serratia Marcescens ◽

Nitrogen Source ◽

Yeast Extract ◽

Value Added ◽

Chitinase Activity ◽

Medium Composition ◽

Colloidal Chitin ◽

Additional Carbon Source ◽

Additional Nitrogen

Chitin hydrolysate is one of the value added product derived from shrimp shell waste. Production of chitin hydrolysate using biological process offers an environmental friendly method compared to chemical process. Serratia marcescens PT-6, a gram negative chitinolytic bacterium isolated from shrimp pond sediment, shows good activity in hydrolyzing chitin. This study aimed to improve the chitinase activity of S. marcescens PT-6 culture by optimizing the component of chitin-containing medium (additional nitrogen source, additional carbon source, and colloidal chitin). The optimization of chitinase by S. marcescens PT-6 culture was done using one variable at a time method. The sequence of the research were to optimize 1) the type of additional carbon source (glucose, lactose, sucrose, and starch), 2) the type of additional nitrogen source (yeast extract, peptone, ammonium sulphate, and ammonium chloride), 3) the concentration of colloidal chitin (0.5; 1; 1.5; 2; and 2.5%), and 4) the concentration of the additional carbon and nitrogen source. The culture of S. marcescens PT-6 was incubated in colloidal chitin medium at 30 oC and chitinase activity from culture supernatant was analyzed. The results showed that starch gave the highest chitinase activity compare to other carbon source, meanwhile yeast extract was chosen as the best nitrogen source among others. The combination of 1.5% colloidal chitin with 0.5% starch and 0.1% yeast extract in medium increased the chitinase activity of S. marcescens PT-6 to 0.021 U/ml. These results indicated that an appropriate medium composition could increase the chitinase activity produced by S. marcescens PT-6 culture.

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A kinetic model of the central carbon metabolism for acrylic acid production in Escherichia coli

PLoS Computational Biology ◽

10.1371/journal.pcbi.1008704 ◽

2021 ◽

Vol 17 (3) ◽

pp. e1008704

Author(s):

Alexandre Oliveira ◽

Joana Rodrigues ◽

Eugénio Campos Ferreira ◽

Lígia Rodrigues ◽

Oscar Dias

Keyword(s):

Escherichia Coli ◽

Carbon Source ◽

Acrylic Acid ◽

Value Added ◽

Central Carbon Metabolism ◽

Scale Production ◽

Over Expression ◽

A Value ◽

Malonyl Coa ◽

Glycerol 3 Phosphate Dehydrogenase

Acrylic acid is a value-added chemical used in industry to produce diapers, coatings, paints, and adhesives, among many others. Due to its economic importance, there is currently a need for new and sustainable ways to synthesise it. Recently, the focus has been laid in the use of Escherichia coli to express the full bio-based pathway using 3-hydroxypropionate as an intermediary through three distinct pathways (glycerol, malonyl-CoA, and β-alanine). Hence, the goals of this work were to use COPASI software to assess which of the three pathways has a higher potential for industrial-scale production, from either glucose or glycerol, and identify potential targets to improve the biosynthetic pathways yields. When compared to the available literature, the models developed during this work successfully predict the production of 3-hydroxypropionate, using glycerol as carbon source in the glycerol pathway, and using glucose as a carbon source in the malonyl-CoA and β-alanine pathways. Finally, this work allowed to identify four potential over-expression targets (glycerol-3-phosphate dehydrogenase (G3pD), acetyl-CoA carboxylase (AccC), aspartate aminotransferase (AspAT), and aspartate carboxylase (AspC)) that should, theoretically, result in higher AA yields.

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Business Strategies of The Chinese Iron & Steel Company Using A Benchmarking on POSCO: Based on A Value-added Analysis

Productivity Review ◽

10.15843/kpapr.28.1.201403.5 ◽

2014 ◽

Vol 28 (1) ◽

pp. 5-26

Author(s):

Juan-Juan Hu ◽

Inseon Yoo

Keyword(s):

Value Added ◽

Business Strategies ◽

Steel Company ◽

A Value

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Novel CO2-Thermic Oxidation Process with Mg-Based Intermetallic Compounds and Its Application to Energy Storage Materials

10.26434/chemrxiv.6838478 ◽

2018 ◽

Author(s):

Younghwan Cha ◽

Jung-In Lee ◽

Panpan Dong ◽

Xiahui Zhang ◽

Min-Kyu Song

Keyword(s):

Intermetallic Compounds ◽

Oxidation Process ◽

Value Added ◽

Energy Storage Materials ◽

Reaction Products ◽

Materials Synthesis ◽

Energy Materials ◽

A Value ◽

Carbon Coated ◽

Novel Strategy

A novel strategy for the oxidation of Mg-based intermetallic compounds using CO<sub>2</sub> as an oxidizing agent was realized via simple thermal treatment, called ‘CO2-thermic Oxidation Process (CO-OP)’. Furthermore, as a value-added application, electrochemical properties of one of the reaction products (carbon-coated macroporous silicon) was evaluated. Considering the facile tunability of the chemical/physical properties of Mg-based intermetallics, we believe that this route can provide a simple and versatile platform for functional energy materials synthesis as well as CO<sub>2</sub> chemical utilization in an environment-friendly and sustainable way.

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