Article
Biotechnology & Applied Microbiology
Alvaro Diaz-Barrera, Francisco Sanchez-Rosales, Claudio Padilla-Cordova, Rodrigo Andler, Carlos Pena
Summary: The study shows that oxygen transfer rates significantly affect alginate production and molecular weight, optimizing OTR can increase alginate yield and improve its properties.
BIOPROCESS AND BIOSYSTEMS ENGINEERING
(2021)
Article
Biotechnology & Applied Microbiology
Angie Johanna Torres-Pedraza, Holjes Salgado-Lugo, Daniel Segura, Alvaro Diaz-Barrera, Carlos Pena
Summary: The study evaluated changes in PHBV composition by the PHB overproducing mutant OPNA of Azotobacter vinelandii under different conditions. Results showed that OTR significantly affected PHBV composition, with higher 3HV content achieved at higher OTRmax. Manipulating OTR could be a feasible strategy for producing PHBV copolymers with different monomeric compositions at an industrial level.
JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY
(2021)
Article
Biotechnology & Applied Microbiology
Viviana Urtuvia, Belen Ponce, Rodrigo Andler, Carlos Pena, Alvaro Diaz-Barrera
Summary: The production and composition of PHBV are influenced by the aeration rate. Higher aeration rates led to increased PHBV production but did not affect the 3HV fraction. The most suitable oxygen transfer rate for improving PHBV content, 3HV fraction, and volumetric productivity was found to be 24.9 mmol L-1 h(-1). This study provides insights into optimizing PHBV production for different biotechnological applications.
Article
Biotechnology & Applied Microbiology
Belen Ponce, Viviana Urtuvia, Nataly Maturana, Carlos Pena, Alvaro Diaz-Barrera
Summary: The study found that under controlled oxygen transfer rate conditions, Alginate production was higher in batch cultures of Azotobacter vinelandii, and the molecular weight was stable; the expression of alginate lyase alyA1 was more affected by oxygen transfer rate control.
ELECTRONIC JOURNAL OF BIOTECHNOLOGY
(2021)
Article
Biochemistry & Molecular Biology
Viviana Urtuvia, Belen Ponce, Rodrigo Andler, Alvaro Diaz-Barrera
Summary: This study evaluated PHBV films with different 3-hydroxyvalerate (3HV) contents produced by Azotobacter vinelandii OP. The results showed that a higher 3HV content improved the thermomechanical properties of PHBV films, reduced the polymer melting point, and affected the tensile strength. Additionally, thermomechanical properties played an important role in biodegradation.
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
(2023)
Article
Biology
Amanda K. Garcia, Derek F. Harris, Alex J. Rivier, Brooke M. Carruthers, Azul Pinochet-Barros, Lance C. Seefeldt, Betul Kacar
Summary: Through experiments, it was found that the ancestors of nitrogenase still have the ability to reduce dinitrogen, which may limit the selection range of life in catalyzing the most energetically challenging biochemical reaction. This provides an important experimental framework for further studying the formation of nitrogenase functionality.
Article
Biotechnology & Applied Microbiology
Enrique Raga-Carbajal, Guadalupe Espin, Marcela Ayala, Julieta Rodriguez-Salazar, Liliana Pardo-Lopez
Summary: In this study, a LEA protein AvLEA1 was found to provide protection to enzymes and showed potential as a biological stabilizer reagent. AvLEA may act as a molecular chaperone or shield to prevent enzyme dissociation or aggregation, or function as a radical scavenger to prevent damage to enzymes under stress conditions.
APPLIED MICROBIOLOGY AND BIOTECHNOLOGY
(2022)
Article
Biochemistry & Molecular Biology
Rodrigo Andler, Victoria Rojas, Valentina Pino, Ricardo I. Castro, Cristian Valdes, Vinay Kumar, Carlos Pena, Alvaro Diaz-Barrera
Summary: Fruit residues, particularly apple peel, were used as the carbon source to produce poly-3-hydroxybutyrate (P3HB) by Azotobacter vinelandii OP bacteria. Sulfuric acid and water were used to effectively convert the residues into sugars, with conversion rates of 65.4% and 58.3%, respectively. Shake-flask and bioreactor cultures with apple residues achieved P3HB production yields of up to 3.94 g L-1 and an accumulation rate of 67.3%w w-1. The obtained PHB had a melting point of 179.99℃ and a maximum degradation temperature of 274.64℃. This study demonstrates the potential of using easily hydrolysable fruit residues for sustainable P3HB production.
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
(2023)
Article
Biology
Trixia M. Buscagan, Jens T. Kaiser, Douglas C. Rees
Summary: This study presents crystallographic data demonstrating chalcogenide exchange at the Fe4S4 cluster of nitrogenase Fe protein under certain conditions, revealing the unique properties of Fe protein in nitrogenase reactions.
Article
Microbiology
Aurelie Joublin-Delavat, Katia Touahri, Pauline Cretin, Amandine Morot, Sophie Rodrigues, Bruno Jesus, Florian Trigodet, Francois Delavat
Summary: Nitrogen fixation by marine non-cyanobacterial diazotrophs (NCD) plays a crucial role in primary production in oceans. The ecophysiology of NCD has been elusive due to limited isolates and lack of genetic tools. This study used a dual genetic and functional approach to uncover the ecophysiology of a marine NCD, Vibrio diazotrophicus. The mutant analysis revealed the importance of the NCD gene, nifH, for growth in nitrogen-free media. The study also found that V. diazotrophicus produces biofilm as an adaptive response to cope with the inhibition of nitrogen fixation by molecular oxygen. Interestingly, the genomic signature of V. diazotrophicus is largely absent from metagenomic data of Tara Ocean expeditions, despite its isolation from various marine environments.
ENVIRONMENTAL MICROBIOLOGY
(2022)
Article
Biochemistry & Molecular Biology
Karen Rodriguez-Martinez, Luis F. Muriel-Millan, Cristian Ortiz-Vasco, Soledad Moreno, Gloria Soberon-Chavez, Guadalupe Espin
Summary: In certain Gram-negative bacteria, the general stress response is regulated by a subunit of RNA polymerase called RpoS. In Escherichia coli, an adaptor protein called RssB is responsible for presenting RpoS to the ClpXP protease for degradation. However, in some species from the Pseudomonadaceae family, the adaptor protein for RpoS degradation has not been identified. This study investigated the role of an E. coli RssB-like protein in two representative Pseudomonadaceae species, and found that both the RssB protein and a protein annotated as an anti-sigma factor antagonist (RssC) are necessary for ClpXP-dependent RpoS degradation.
MOLECULAR MICROBIOLOGY
(2023)
Article
Biotechnology & Applied Microbiology
Maria Rodriguez-Torres, Juliana Romo-Buchelly, Fernando Orozco-Sanchez
Summary: In this study, the effects of different oxygen transfer rates on the performance of Rhizopus oryzae were analyzed. The results showed that the highest lactid acid productivity and production were achieved at a certain range of oxygen transfer rates. Additionally, a dimensionless analysis determined the optimal conditions for lactid acid production.
BIOCHEMICAL ENGINEERING JOURNAL
(2022)
Article
Biotechnology & Applied Microbiology
Brett M. Barney, Mary H. Plunkett
Summary: This study demonstrates that the Rnf1 complex in Azotobacter vinelandii is the primary source of electrons for nitrogenase in a partially deregulated strain. When the Fix complex is unable to provide enough electrons, relocating its genes can increase ammonium accumulation.
APPLIED MICROBIOLOGY AND BIOTECHNOLOGY
(2022)
Article
Multidisciplinary Sciences
Schara Safarian, Helen K. Opel-Reading, Di Wu, Ahmad R. Mehdipour, Kiel Hards, Liam K. Harold, Melanie Radloff, Ian Stewart, Sonja Welsch, Gerhard Hummer, Gregory M. Cook, Kurt L. Krause, Hartmut Michel
Summary: The study presents the structure of M. tuberculosis cytochrome bd oxidase and identifies a disulfide bond and a menaquinone-9 binding site. These findings provide insights for designing highly specific drugs to target this enzyme.
NATURE COMMUNICATIONS
(2021)
Article
Microbiology
Claudia Velazquez-Sanchez, Miguel Angel Vences-Guzman, Soledad Moreno, Raunel Tinoco-Valencia, Guadalupe Espin, Josefina Guzman, Diana X. Sahonero-Canavesi, Christian Sohlenkamp, Daniel Segura
Summary: The inactivation of PsrA in Azotobacter vinelandii reduces the synthesis and content of unsaturated fatty acids, resulting in decreased cell viability. This study demonstrates the important role of PsrA in the regulation of unsaturated fatty acid metabolism by positively regulating fabAB.
MICROBIOLOGICAL RESEARCH
(2021)
Article
Biochemistry & Molecular Biology
Elsa Gomez-Hernandez, Holjes Salgado-Lugo, Daniel Segura, Andres Garcia, Alvaro Diaz-Barrera, Carlos Pena
Summary: The study aimed to evaluate the effect of oxygen transfer rate (OTR) on the molecular weight of Poly-3-hydroxybutyrate (P3HB). The results showed that manipulating oxygen transfer conditions could modulate the average molecular weight of P3HB, with strains grown at lower OTR conditions producing higher molecular weight P3HB.
APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY
(2021)
Article
Biotechnology & Applied Microbiology
Alvaro Diaz-Barrera, Francisco Sanchez-Rosales, Claudio Padilla-Cordova, Rodrigo Andler, Carlos Pena
Summary: The study shows that oxygen transfer rates significantly affect alginate production and molecular weight, optimizing OTR can increase alginate yield and improve its properties.
BIOPROCESS AND BIOSYSTEMS ENGINEERING
(2021)
Article
Biotechnology & Applied Microbiology
Belen Ponce, Viviana Urtuvia, Nataly Maturana, Carlos Pena, Alvaro Diaz-Barrera
Summary: The study found that under controlled oxygen transfer rate conditions, Alginate production was higher in batch cultures of Azotobacter vinelandii, and the molecular weight was stable; the expression of alginate lyase alyA1 was more affected by oxygen transfer rate control.
ELECTRONIC JOURNAL OF BIOTECHNOLOGY
(2021)
Article
Biotechnology & Applied Microbiology
Angie Johanna Torres-Pedraza, Holjes Salgado-Lugo, Daniel Segura, Alvaro Diaz-Barrera, Carlos Pena
Summary: The study evaluated changes in PHBV composition by the PHB overproducing mutant OPNA of Azotobacter vinelandii under different conditions. Results showed that OTR significantly affected PHBV composition, with higher 3HV content achieved at higher OTRmax. Manipulating OTR could be a feasible strategy for producing PHBV copolymers with different monomeric compositions at an industrial level.
JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY
(2021)
Article
Environmental Sciences
C. Valdes, C. Hernandez, R. Morales-Vera, R. Andler
Summary: A comparison study was conducted on two different desulfurization methods for rubber recycling: one biological and one chemical. The chemical method produced significantly higher amounts of sulfate and showed a higher decrease in cross-linking compared to the biological method. FTIR and SEM-EDS analysis revealed structural and morphological changes in the rubber samples after treatment with both desulfurization methods.
FRONTIERS IN ENVIRONMENTAL SCIENCE
(2021)
Article
Polymer Science
Yvan Baldera-Moreno, Valentina Pino, Amelia Farres, Aparna Banerjee, Felipe Gordillo, Rodrigo Andler
Summary: The strong environmental impact of plastic pollution has led to research from various perspectives. The mathematical modeling of the biodegradation kinetics of solid materials is challenging due to the numerous influential variables and the interdependence of microorganisms with internal and external factors. This review summarizes the biochemical fundamentals of plastics involved in biodegradation processes and presents various mathematical models and experimental studies, aiming to provide a comprehensive overview and serve as a reference for future research.
Article
Biotechnology & Applied Microbiology
R. Andler, V. D'Afonseca, J. Pino, C. Valdes, M. Salazar-Viedma
Summary: Millions of tonnes of tyre waste are discarded annually and considered difficult to recycle, leading researchers to explore biodegradation of vulcanised rubber using microorganisms. Fungal strains like Trametes versicolor and Pleurotus ostreatus showed promising biodegradation capabilities, supported by genetic and bioinformatics tools for deeper analysis of the process. Enzyme activities of laccases and manganese peroxidases were significantly increased in cultures with rubber particles, indicating potential for more efficient biotechnological solutions in the future.
FRONTIERS IN BIOENGINEERING AND BIOTECHNOLOGY
(2021)
Article
Polymer Science
Cesar Barrientos-Sanhueza, Danny Cargnino-Cisternas, Alvaro Diaz-Barrera, Italo F. Cuneo
Summary: This study investigated the hydro-mechanical behavior of different soils media treated with Ca-bacterial alginate hydrogel. The results showed that increasing kaolinite and water content can improve the yield stress and aggregate stability of the treated soils. Temperature also played a role in the gelation capacity of the hydrogel. Adding kaolinite decreased the saturated hydraulic conductivity of the soils.
Article
Biotechnology & Applied Microbiology
Rodrigo Andler, Camila Guajardo, Catalina Sepulveda, Valentina Pino, Vilma Sanhueza, Vivian D'Afonseca
Summary: This study characterizes the degradation of rubber-containing substrates using the bacterium Rhodococcus rhodochrous and the oxygenase latex clearing protein (Lcp). It found that R. rhodochrous can degrade polyisoprene particles in liquid cultures, and Lcp has high activity at appropriate conditions. The bioconversion rate of natural rubber and the mass distribution of degradation products were also analyzed.
Review
Biotechnology & Applied Microbiology
Rodrigo Andler, Till Tiso, Lars Blank, Christina Andreessen, Jessica Zampolli, Vivian D'Afonseca, Camila Guajardo, Alvaro Diaz-Barrera
Summary: Plastic pollution is a global concern due to the slow biodegradation of synthetic plastics. There is a need to supplement the existing knowledge on the biodegradation and biotransformation of synthetic plastics to develop effective bioremediation strategies. This review aims to highlight current research on the most promising biodegradation processes, plastic-degrading enzymes, biotechnological strategies for improvement, and the bioconversion of plastic waste. Techno-economic analyses and environmental impacts are also discussed to facilitate the valorization of plastic biodegradation processes.
REVIEWS IN ENVIRONMENTAL SCIENCE AND BIO-TECHNOLOGY
(2022)
Article
Biotechnology & Applied Microbiology
Viviana Urtuvia, Belen Ponce, Rodrigo Andler, Carlos Pena, Alvaro Diaz-Barrera
Summary: The production and composition of PHBV are influenced by the aeration rate. Higher aeration rates led to increased PHBV production but did not affect the 3HV fraction. The most suitable oxygen transfer rate for improving PHBV content, 3HV fraction, and volumetric productivity was found to be 24.9 mmol L-1 h(-1). This study provides insights into optimizing PHBV production for different biotechnological applications.
Article
Biotechnology & Applied Microbiology
Pablo Contreras-Abara, Tania Castillo, Belen Ponce, Viviana Urtuvia, Carlos Pena, Alvaro Diaz-Barrera
Summary: This study aimed to develop a continuous bioprocess and compare alginate production under diazotrophic and nondiazotrophic conditions. The results showed that under diazotrophic conditions, there was higher efficiency, yield, and specific productivity rates of sucrose conversion to alginate. The molecular weight of alginate was also higher under diazotrophic conditions.
FERMENTATION-BASEL
(2023)
Article
Biochemistry & Molecular Biology
Ernesto Gonzalez, Camila Zuleta, Guiselle Zamora, Nataly Maturana, Belen Ponce, Maria Virginia Rivero, Alberto Rodriguez, Juan Pablo Soto, Felipe Scott, Alvaro Diaz-Barrera
Summary: This study characterized the production of PHB and EPS by the acidophilic bacterium A. cryptum using glycerol. The results showed that maximum PHB accumulation was achieved at specific glycerol concentrations, and PHB production in the bioreactor was influenced by oxygen limitation. Analysis of the recovered EPS revealed the presence of mannose, rhamnose, and glucose.
Article
Biochemistry & Molecular Biology
Viviana Urtuvia, Belen Ponce, Rodrigo Andler, Alvaro Diaz-Barrera
Summary: This study evaluated PHBV films with different 3-hydroxyvalerate (3HV) contents produced by Azotobacter vinelandii OP. The results showed that a higher 3HV content improved the thermomechanical properties of PHBV films, reduced the polymer melting point, and affected the tensile strength. Additionally, thermomechanical properties played an important role in biodegradation.
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
(2023)