Production of Succinic Acid From Basfia succiniciproducens

Basfia succiniciproducens is a facultative anaerobic capnophilic bacterium, isolated from rumen, that naturally produces high amounts of succinic acid by fixing CO2 and using fumarate as final electron acceptor. This metabolic feature makes it one of the ideal candidates for developing biotechnological industrial routes that could eventually replace the polluting and environment unfriendly petrochemical ones that are still main sources for the production of this value-added compound. In fact, due to the large number of applications of succinic acid that range from the more traditional ones as food additive or pharmaceutical intermediate to the most recent as building block for biopolymers and bioplastic, increasing demand and market size growth are expected in the next years. In line with a “green revolution” needed to preserve our environment, the great challenge is the establishment of commercially viable production processes that exploit renewable materials and in particular preferably non-food lignocellulosic biomasses and waste products. In this review, we describe the currently available literature concerning B. succiniciproducens since the strain was first isolated, focusing on the different renewable materials and fermentation strategies used to improve succinic acid production titers to date. Moreover, an insight into the metabolic engineering approaches and the key physiological characteristics of B. succiniciproducens deduced from the different studies are presented.

Pengaruh Nitrat terhadap Biokorosi Logam oleh Konsorsium Bakteri Pereduksi Sulfat dari PLTA Saguling

<div><strong>The Influence of Nitrate in Metal Biocorrosion caused by Sulfate Reducing Bacteria from Saguling Hydropower</strong>. The corrosion facilitated and accelerated by the activities of microorganism is called biocorrosion. Sulfate reducing bacteria (SRB) is known as the bacteria that cause biocorrosion in anaerobic condition by using sulfate as the final electron acceptor. Biocorrosion reduces equipment lifetime and increases maintenance cost in industry. In the cooling system in Saguling hydropower, corrosion was commonly caused by utilization of contaminated water due to anorganic and organic waste, especially sulfate. In this research, sulfate reducing bacteria was isolated from biofilms in the cooling system of Saguling Hydropower. Molecular analysis using PCR-DGGE method with dsrB gene (350 bp) as molecular markers showed that SRB consortium contained 12 bands and assumed as different species of SRB. SRB consortium was tested to determine its biocorrosion activity over metal material of ST37 (carbon steel) and SUS304 (stainless steel). The consortium then treated with 7 different nitrate concentrations to determine its effect against the sulfate reducing bacteria activity. SRB consortium caused higher corrosion to ST37 than SUS304L, with the corrosion rate of 0.07660 mm/year and 0.00265 mm/year, respectively. Concentration of 10 mM nitrate effectively inhibited corrosion rate on ST37 and caused the changes in sulfate reducing bacteria communities, indicated by the disappearance of 6 bands in DGGE profile</div>

Matily Herbal Drink May Reduce Oxidative Stress, Hyperglycemia, and Hyperlipidemia and Increases Immunity - Case Study Reports

Oxygen is an element indispensable for all aerobic organisms to sustain life (1). Cells produce energy mainly in the mitochondria through oxidative phosphorylation, a series of electron transfer in the Electron Transport Chain (ETC), where oxygen is the final electron acceptor. During this process, it creates free radicles by the mitochondria. Oxidative stress produces free radicals. A 70 Kgs man may produce nearly 2 Kg of free radicals in his body in a year (2). It is comparatively a huge amount. Examples offree radicals with one or more unpaired electrons are superoxide, hydroxyl, andnitric oxide radicals (1, 3). A molecule like oxygen is stable when it shares its electrons in the paired state, when it loses or gains an extra electron, it becomes unstable. This condition leads them to “steal” or take it from other biomolecules. This process leaves the biomolecules in the oxidative state, which can start pathological conditions. For example, when Low-Density Lipoproteins when becomingoxidized, causes atherosclerosis in the blood vessels and cause plaques inside the arteries (4).

Experimental oxygen concentration influences rates of mitochondrial hydrogen peroxide release from cardiac and skeletal muscle preparations

Mitochondria utilize the majority of oxygen (O2) consumed by aerobic organisms as the final electron acceptor for oxidative phosphorylation (OXPHOS) but also to generate reactive oxygen species (mtROS) that participate in cell signaling, physiological hormesis, and disease pathogenesis. Simultaneous monitoring of mtROS production and oxygen consumption ( Jo2) from tissue mitochondrial preparations is an attractive investigative approach, but it introduces dynamic changes in media O2 concentration ([O2]) that can confound experimental results and interpretation. We utilized high-resolution fluorespirometry to evaluate Jo2 and hydrogen peroxide release ( Jh2o2) from isolated mitochondria (Mt), permeabilized fibers (Pf), and tissue homogenates (Hm) prepared from murine heart and skeletal muscle across a range of experimental [O2]s typically encountered during respirometry protocols (400–50 µM). Results demonstrate notable variations in Jh2o2 across tissues and sample preparations during nonphosphorylating (LEAK) and OXPHOS-linked respiration states at 250 µM [O2] but a linear decline in Jh2o2 of 5–15% per 50-µM decrease in chamber [O2] in all samples. Jo2 was generally stable in Mt and Hm across [O2]s above 50 µM but tended to decline below 250 µM in Pf, leading to wide variations in assayed rates of Jh2o2/O2 across chamber [O2]s and sample preparations. Development of chemical background fluorescence from the H2O2 probe (Amplex Red) was also O2 sensitive, emphasizing relevant calibration considerations. This study highlights the importance of monitoring and reporting the chamber [O2] at which Jo2 and Jh2o2 are recorded during fluorespirometry experiments and provides a basis for selecting sample preparations for studies addressing the role of mtROS in physiology and disease.

Metabolism

Metabolism is driven by redox reactions, in which part of the difference in potential energy between the electron donor and acceptor is used by the organism for its life processes (with the remainder being dissipated as heat). The key process is intermediary metabolism, by which the energy stored in reserves (glycogen, starch, lipid, protein) is transferred to ATP. In aerobic respiration the electrons released from reserves are passed to oxygen, which is thereby reduced to water. Not all ATP regeneration involves oxygen as the final electron acceptor, and not all oxygen is used for ATP regeneration, but oxygen consumption is often the simplest and most practical way to measure the rate of intermediary metabolism and the errors in doing so are believed to be small. The costs of existence, as estimated by resting metabolism, represent only a part (~ 25%) of the daily energy expenditure of organisms. The costs of the organism’s ecology (growth, reproduction, movement and so on) are additional to existence costs. Resting metabolic rate increases with cell temperature, indicating that it costs more energy to maintain a warm cell than it does a cool or cold cell. The temperature sensitivity of resting metabolism is highly conserved across organisms.

Assembly pathway of a bacterial complex iron sulfur molybdoenzyme

Protein folding and assembly into macromolecule complexes within the living cell are complex processes requiring intimate coordination. The biogenesis of complex iron sulfur molybdoenzymes (CISM) requires use of a system specific chaperone – a redox enzyme maturation protein (REMP) – to help mediate final folding and assembly. The CISM dimethyl sulfoxide (DMSO) reductase is a bacterial oxidoreductase that utilizes DMSO as a final electron acceptor for anaerobic respiration. The REMP DmsD strongly interacts with DMSO reductase to facilitate folding, cofactor-insertion, subunit assembly and targeting of the multi-subunit enzyme prior to membrane translocation and final assembly and maturation into a bioenergetic catalytic unit. In this article, we discuss the biogenesis of DMSO reductase as an example of the participant network for bacterial CISM maturation pathways.

Biology of Ageing and Role of Dietary Antioxidants

Interest in relationship between diet and ageing is growing. Research has shown that dietary calorie restriction and some antioxidants extend lifespan in various ageing models. On the one hand, oxygen is essential to aerobic organisms because it is a final electron acceptor in mitochondria. On the other hand, oxygen is harmful because it can continuously generate reactive oxygen species (ROS), which are believed to be the factors causing ageing of an organism. To remove these ROS in cells, aerobic organisms possess an antioxidant defense system which consists of a series of enzymes, namely, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and glutathione reductase (GR). In addition, dietary antioxidants including ascorbic acid, vitamin A, vitamin C,α-tocopherol, and plant flavonoids are also able to scavenge ROS in cells and therefore theoretically can extend the lifespan of organisms. In this connection, various antioxidants including tea catechins, theaflavins, apple polyphenols, black rice anthocyanins, and blueberry polyphenols have been shown to be capable of extending the lifespan of fruit flies. The purpose of this review is to brief the literature on modern biological theories of ageing and role of dietary antioxidants in ageing as well as underlying mechanisms by which antioxidants can prolong the lifespan with focus on fruit flies as an model.

Extracellular Electron Transport-Mediated Fe(III) Reduction by a Community of Alkaliphilic Bacteria That Use Flavins as Electron Shuttles

ABSTRACTThe biochemical and molecular mechanisms used by alkaliphilic bacterial communities to reduce metals in the environment are currently unknown. We demonstrate that an alkaliphilic (pH > 9) consortium dominated byTissierella,Clostridium, andAlkaliphilusspp. is capable of using iron (Fe3+) as a final electron acceptor under anaerobic conditions. Iron reduction is associated with the production of a freely diffusible species that, upon rudimentary purification and subsequent spectroscopic, high-performance liquid chromatography, and electrochemical analysis, has been identified as a flavin species displaying properties indistinguishable from those of riboflavin. Due to the link between iron reduction and the onset of flavin production, it is likely that riboflavin has an import role in extracellular metal reduction by this alkaliphilic community.