Thelmo A Lu-Chau | University of Santiago de Compostela (original) (raw)

Papers by Thelmo A Lu-Chau

Waste and Biomass Valorization, Oct 21, 2021

Food and Bioproducts Processing, Nov 1, 2020

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Biochemical Engineering Journal, Feb 1, 2020

Waste Management, Jun 1, 2023

Applied Microbiology and Biotechnology, Jan 25, 2022

Enzymes offer interesting features as biological catalysts for industry: high specificity, activi... more Enzymes offer interesting features as biological catalysts for industry: high specificity, activity under mild conditions, accessibility, and environmental friendliness. Being able to produce enzymes in large quantities and having them available in a stable and reusable form reduces the production costs of any enzyme-based process. Agricultural residues have recently demonstrated their potential as substrates to produce ligninolytic enzymes by different white rot fungi. In this study, the biotechnological production of a manganese peroxidase (MnP) by Irpex lacteus was conducted through solid-state fermentation (SSF) with wheat straw as substrate and submerged fermentation (SmF) employing wheat straw extract (WSE). The obtained enzyme cocktail also showed manganese-independent activity (MiP), related to the presence of a short MnP and a dye-decolorizing peroxidase (DyP) which was confirmed by shotgun proteomic analyses. In view of the enhanced production of ligninolytic enzymes in SmF, different parameters such as WSE concentration and nitrogen source were evaluated. The highest enzyme titers were obtained with a medium formulated with glucose and peptone (339 U/L MnP and 15 U/L MiP). The scale-up to a 30 L reactor achieved similar activities, demonstrating the feasibility of enzyme production from the residual substrate at different production scales. Degradation of five emerging pollutants was performed to demonstrate the high oxidative capacity of the enzyme. Complete removal of hormones and bisphenol A was achieved in less than 1 h, whereas almost 30% degradation of carbamazepine was achieved in 24 h, which is a significant improvement compared to previous enzymatic treatments of this compound. Key points • Wheat straw extract is suitable for the growth of I. lacteus. • The enzyme cocktail obtained allows the degradation of emerging contaminants. • Mn-dependent and Mn-independent activities increases the catalytic potential.

Science of The Total Environment, Aug 1, 2020

Horse chestnut burs (HCB) was explored as a potential source of valuable biocompounds • 11 phenol... more Horse chestnut burs (HCB) was explored as a potential source of valuable biocompounds • 11 phenolics from HCB extracts were identified by UPLC-DAD-ESI-MS • Structural profile and thermal stability of HCBE were reported by the first time • Antioxidants-free solid was exploited for obtaining glucose and lignin • HCB based biorefinery with zero-waste could contribute to sustainable development

Journal of Biotechnology, 2018

Talanta, 2016

With the increasing use of enzymes in environmental applications, there is a need for analytical ... more With the increasing use of enzymes in environmental applications, there is a need for analytical methods adapted to large factorial experiments. Existing reference methods are chemical and labor intensive and unsuitable to analyze in parallel a large number of samples. Based on an extensive literature review and on experimental results, this work compares reference and microplate adapted methods to define the most adequate filter paper, carboxymethylcellulase, β-glucosidase and xylanase activity tests. In the adapted methods, the total reaction volume was reduced from 2.2-24.5 mL to 0.21-0.24 mL. Statistical analysis of the activities measured on enzyme mixtures by applying the 96-well plate reduced methods showed that they were not significantly different to the activities obtained with reference tests.

Biomass Conversion and Biorefinery, Jan 17, 2022

Fungal pretreatment of lignocellulosic biomass for bioethanol production is an environmental-frie... more Fungal pretreatment of lignocellulosic biomass for bioethanol production is an environmental-friendly alternative to steam explosion. However, this biological pretreatment has been tested on a small scale, where most of the typical problems of solid-state fermentations (SSF), such as limited aeration or temperature control, are not observed. The main objective of this study was to assess the feasibility of the fungal pretreatment of lignocellulosic biomass (wheat straw) at a demonstration scale using the white-rot fungus Irpex lacteus to improve straw digestibility. Different configurations were evaluated for the design of a 22 L SSF reactor, but a versatile vertical design that can operate as a packed-bed and as a tray reactor was selected. The wheat straw digestibility obtained in the SSF bioreactor after 21 days of pretreatment (60.6%) was similar to that achieved on a small scale (57.9%). In addition, the most common online monitoring variables (temperature and CO 2 production) correlate with the fungal action on wheat straw. As well as the weight loss, obtaining comparable results at flask and reactor scale (30 and 34.5%, respectively).

Industrial Crops and Products, 2016

Industrial Crops and Products

Bioethanol Production from Food Crops, 2019

HIGHLIGHTS Efficacy of biological, chemical, physical and combined pretreatments in enhancing bi... more HIGHLIGHTS Efficacy of biological, chemical, physical and combined pretreatments in enhancing biomethane production from crop residues compared. Physical and chemical pre-treatment methods are the most effective and fastest. Disadvantages of physical and chemical pretreatments are high cost of resources, operation and energy as well as formation of inhibitory byproducts. Combined pretreatment processes are fast and cost effective but have limited utility due to generation of-Biological pretreatment is inexpensive, eco-friendly

SSRN Electronic Journal, 2021

Catalysts, 2018

The enzyme-mediated polymerization of bioactive phenolic compounds, such as the flavonoid rutin, ... more The enzyme-mediated polymerization of bioactive phenolic compounds, such as the flavonoid rutin, has gained interest due to the enhanced physico-chemical and biological properties of the products, which increases their potential application as a nutraceutical. In this work, the influence of enzyme activity on rutin oligomerization was evaluated in reactions with low (1000 U/L) and high (10,000 U/L) initial laccase activities. For both reactions, high molecular weight oligomer fractions showed better properties compared to lower weight oligomers. Products of the reaction with low laccase activity exhibited thermal stability and antioxidant potential similar to control reaction, but led to higher inhibitory activity of xanthine oxidase and apparent aqueous solubility. Oligomers obtained in the reaction with high laccase activity showed better apparent aqueous solubility but decreased biological activities and stability. Their low antioxidant activity was correlated with a decreased ph...

Encyclopedia of Membranes, 2014

Biotechnology progress, Jan 29, 2015

The oxidant Mn(3+) -malonate, generated by the ligninolytic enzyme versatile peroxidase in a two-... more The oxidant Mn(3+) -malonate, generated by the ligninolytic enzyme versatile peroxidase in a two-stage system, was used for the continuous removal of endocrine disrupting compounds (EDCs) from synthetic and real wastewaters. One plasticizer (bisphenol-A), one bactericide (triclosan) and three estrogenic compounds (estrone, 17β-estradiol, and 17α-ethinylestradiol) were removed from wastewater at degradation rates in the range of 28-58 µg/L·min, with low enzyme inactivation. First, the optimization of three main parameters affecting the generation of Mn(3+) -malonate (hydraulic retention time as well as Na-malonate and H2 O2 feeding rates) was conducted following a response surface methodology (RSM). Under optimal conditions, the degradation of the EDCs was proven at high (1.3-8.8 mg/L) and environmental (1.2-6.1 µg/L) concentrations. Finally, when the two-stage system was compared with a conventional enzymatic membrane reactor (EMR) using the same enzyme, a 14-fold increase of the re...

Applied biochemistry and biotechnology, 2015

The ligninolytic enzymes versatile peroxidase (VP) and manganese peroxidase (MnP) have been previ... more The ligninolytic enzymes versatile peroxidase (VP) and manganese peroxidase (MnP) have been previously described as efficient oxidizers of the endocrine disrupting chemical (EDC) nonylphenol at high concentrations of the pollutant. Envisaging the application of an enzymatic technology as a tertiary treatment in wastewater treatment plants, it is important to design a continuous reactor that performs the efficient removal of nonylphenol under environmental conditions. In the present research, a two-stage membrane bioreactor based on the production and use of Mn(3+)-malonate (chemical oxidant) was applied. The bioreactor consisted of an enzymatic reactor (R1) for the production of Mn(3+)-malonate by VP, coupled to an oxidation reactor (R2), where the oxidation of nonylphenol by Mn(3+)-malonate took place. The production of Mn(3+)-malonate in R1 was maintained constant: 500-700 μM with minimal deactivation of the enzyme. The oxidation reactor attained nearly complete removal of nonylph...