Butyric acid is a fatty acid with short-chain (C3H7COOH). The esters of it exist in animal fat and some plant oil naturally [18]. Butyric acid can be used as an ingredient in varnishes, perfumes, pharmaceuticals, disinfectants and used for producing plastics, plasticizers, surfactants and textile auxiliaries [18]. It can be applied in animal feeds and used as flavoring agent in food products with the form of esters and salts [18]. It also can serve as substrate to produce butanol [1, 2]. Butyric acid can be produced by petrochemical or biological methods [18,76]. Although nowadays butyric acid is mostly produced from petroleum feedstocks, producing it from renewable feedstocks by microbial fermentation draws more attention due to the limited resources and application as food additives or cosmetic products [18,22].
In the microbial fermentation, a number of gram-positive, obligate anaerobic microorganisms have the ability to produce butyric acid in significant quantities like Clostridium sp. and Butyrivibrio fibrisolnes [18]. Among these, Clostridium tyrobutyricum, a gram-positive and obligate anaerobic bacterium, is most promising because of its capability of producing butyric acid with high selectivity, tolerance of high concentrations of products [22] and relatively high and stable productions [3, 4, 5, 6].
The metabolic pathway of Clostridium tyrobutyricum is shown in Figure. 1. The end-products are butyrate and butanol while acetate and acetone are byproducts. Lactate and ethanol are produced but just in small amounts [77]. Solvents include butanol, ethanol and acetone are produced when pH <5 during solventogenesis phase. Acids are produced during acidogenesis phase when pH is higher [77]. Acetyl-CoA is branch-point intermedia...
... middle of paper ...
...spectively after dilute-acid pretreatment and enzymatic hydrolysis [26]. Also some research chose 1g/l [27, 28] or 2 g/l [21, 29] as the maximum concentration of furfural. The concentrations of furfural in this research were divided into four levels to be studied: 0.6 g/l, 1.2 g/l, 1.8 g/l and 2.4 g/l.
As to syringaldehyde and vanillin, similar to furfural, concentrations of 0.06g/l and 0.04 g/l were found in the solution of corn strover after sulfuric acid hydrolysis respectively and the author also tested both of them at 2 g/l [24]. Cells of S.cerevisiae and Z. mobilis are mostly killed by 2g/l of vanillin or 1.5 g/l of syringaldehyde [23]. So although the concentrations in the hydrolysis solution were not high, this research still chose a maximum of 2.8 g/l of both of them to do the study. They had same concentration levels: 0.7 g/l, 1.4 g/l, 2.1 g/l and 2.8 g/l.
Table 6 shows the results of the biochemical tests. The isolate can obtain its energy by means of aerobic respiration but not fermentation. In the Oxidation-Fermentation test, a yellow color change was produced only under both aerobic conditions, indicating that the EI can oxidize glucose to produce acidic products. In addition to glucose, the EI can also utilize lactose and sucrose, and this deduction is based on the fact that the color of the test medium broth changed to yellow in all three Phenol Red Broth tests. These results are further supported by the results of the Triple Sugar Iron Agar test. Although the EI does perform fermentation of these three carbohydrates, it appears that this bacterium cannot perform mixed acid fermentation nor 2,3-butanediol fermentation due to the lack of color change in Methyl Red and Vogues-Proskauer
Yersinia pestis is a zoonosis disease categorized in the family enterobacteriaceae. It is a non-spore forming, gram-negative coccobacilli that, when grown on agar, forms pin-point white/translucent colonies. Defining qualities of the Y. pestis are it’s bipolar staining, it’s negative test results for lactose fermentation, urease, and indole production, and positive testing for catalase. This pleomorphic bacterium is facultatively aerobic with an optimal growth temperature at 28 degrees Celsius. At temperatures above 37 degrees Celsius, it appears the Y. pestis is non-motile, but at temperatures less than 30 degrees Ce...
...id, acetic acid, formic acid, H₂ and CO₂ as fermentation products which increases ecological, industrial and basic bioenergetics interests in this particularly thermophilic bacterial specie.
Anthocyanins, flavanols, flavanones,secoiridoids, phenolic acids, stilbenes, coumarins, and isoflavones form a large class of polyphenols, which are phenolic compounds. This study, however, focuses on one category of these phenolic compounds: phenolic acids. These particular compounds have been classified into two groups, namely hydroxycinnamic acids and hydroxybenzoic acids. The most common hydroxybenzoic acids are protocatechuic acid and gallic acid, while hydroxycinnamic acids include ferulic acid, coumaric acid, caffeic acid, chlorogenic acid, and sinapic acid, (Nigdikar, Williams, Griffin, & Howard). Unlike hydroxycinnamic acids, hydroxybenzoic acids usually occur at very low levels in some black radish, red fruits, and onions, accounting for about 10 ppm on a fresh weight basis. Protocatechuic ac...
I agree with him that acetyl CoA is formed in aerobic respiration from pyruvate when the oxygen is present. However, he also mentioned that acetyl CoA is produced from Krebs Cycle which do not require oxygen. I agree with Moez, the Undergraduate TA that there is a contradiction of his statement on acetyl CoA. I believe that might be a typing mistake and he chose choice C acetyl CoA as the correct answer. In Adrian’s comment on real world application of anaerobic respiration, he mentioned that anaerobic respiration affects many processes such as assimilation of carbon dioxide to acetate. In addition to that, anaerobic respiration also affects processes in bacteria such as denitrification. When there is a limited supply of oxygen, bacteria synthesize energy through denitrification. Therefore, anaerobic respiration has a significant role on bacteria production of energy when oxygen is
When the aerobic organisms in the body consume all the oxygen present, anaerobic organisms from the digestive system begin to multiply. They consume macromolecules (proteins, carbohydrates, lipids) and form acids and gases in the p...
Fermentation is a form of chemical transformation of organic substances that breaks down simple compounds by exploiting the enzymes with compl...
The esterification procedure was performed first. To begin the lab, the heating mantle was set at the 6 setting, and the hot plate heat was turned on to low. In a round bottom flask, 6.1 g of benzoic acid and 21 mL of MeOH were added into the flask. Once this was added to the flask, 2 mL of sulfuric acid was added and poured carefully down the side of the flask. It was noted that after the addition of the sulfuric acid there was heat production in the flask. The contents were swirled and a boiling chip was added into the flask. The flask was connected to the hood by a clamp. Water was then ran through the condenser and connected to the round bottom flask to begin refluxing the contents in the flask. The mixture was gently heated at reflux for one hour.
In any production of certain metabolites or products in fungal life cycle, two phases of metabolism must involve which are primary and secondary metabolisms. In this new and modern era, fungal biotechnology has evolved and developed in order to allow a commercially fungal utilization of the metabolic processes in a viable manner. To conclude, fungi have contributed a lot in economy significantly. This included in the industries of chemical commodities, antibiotics, enzymes, vitamins, pharmaceutical compounds, fungicides, plant growth regulators, hormones and proteins.
Stout, M.A, et al. "Microbiology Lab Notebook". Lab handbook. University of Texas. Arlington. 2014. Print.
Bacterial cells, like plant cells, are surrounded by a cell wall. However, bacterial cell walls are made up of polysaccharide chains linked to amino acids, while plant cell walls are made up of cellulose, which contains no amino acids. Many bacteria secrete a slimy capsule around the outside of the cell wall. The capsule provides additional protection for the cell. Many of the bacteria that cause diseases in animals are surrounded by a capsule. The capsule prevents the white blood cells and antibodies from destroying the invading bacterium. Inside the capsule and the cell wall is the cell membrane. In aerobic bacteria, the reactions of cellular respiration take place on fingerlike infoldings of the cell membrane. Ribosomes are scattered throughout the cytoplasm, and the DNA is generally found in the center of the cell. Many bacilli and spirilla have flagella, which are used for locomotion in water. A few types of bacteria that lack flagella move by gliding on a surface. However, the mechanism of this gliding motion is unknown. Most bacteria are aerobic, they require free oxygen to carry on cellular respiration. Some bacteria, called facultatibe anaerobes can live in either the presence or absence of free oxygen. They obtain energy either by aerobic respiration when oxygen is present or by fermentation when oxygen is absent. Still other bacteria cannot live in the presence of oxygen. These are called obligate anaerobes. Such bacteria obtain energy only fermentation. Through fermentation, different groups of bacteria produce a wide variety of organic compounds. Besides ethyl alcohol and lactic acid, bacterial fermentation can produce acetic acid, acetone, butyl alcohol, glycol, butyric acid, propionic acid, and methane, the main component of natural gas. Most bacteria are heterotrophic bacteria are either saprophytes or parasites. Saprophytes feed on the remains of dead plants and animals, and ordinarily do not cause disease. They release digestive enzymes onto the organic matter. The enzymes breakdown the large food molecules into smaller molecules, which are absorbed by the bacterial cells. Parasites live on or in living organisms, and may cause disease. A few types of bacteria are Autotrophic, they can synthesize the organic nutrients they require from inorganic substances. Autotrophic bacteria are either photosynthetic or Chemosynthetic. The photosynthetic bacteria contain chlorophyll that are different from the plant chlorophyll. In bacterial photosynthesis, hydrogen is obtained by the splitting of compounds other than water.
Molisch test is one of the useful qualitative test for presence of carbohydrates in solution. The three glucose solutions all have a violet colored ring formed at the junction between the two layers. This showed that carbohydrates are present in these sugar solution. This test involved the addition of concentrated sulphuric acid which causes dehydration of all carbohydrates to give ‘furfural’ compound, where pentoses are dehydrated to furfural, and hexoses are dehydrated to 5-hydroxymethylfurfural (Molish's reagent, 2009). These compounds will later react with – naphtol which is Molisch reagent to give a purple colored complex. The test has to be carried out slowly as the violet colour formed at the surface of contact of concentrated sulfuric
...osphate acetyltransferase and acetate kinase are the two enzymes used in the second reaction pathway to produce acetate via acetylphosphate. From these reactions one molecule of ATP is gained. The third route for pyruvate degradation is directly to acetate by pyruvate oxidase. Phosphoenolpyruvate, which also is a product of glycolysis, can too enter the mixed acid fermentation. It can form pyruvate and a molecule of ATP or form
Fermentation is an anaerobic process in which fuel molecules are broken down to create pyruvate and ATP molecules (Alberts, 1998). Both pyruvate and ATP are major energy sources used by the cell to do a variety of things. For example, ATP is used in cell division to divide the chromosomes (Alberts, 1998).
...-KLGA three different kind of methods have been used by researchers, In first method which is known as Single-strain processes, strains which belong to genera Gluconobacter, Acetobacter, Ketogulonicigenium, Pseudomonas, Erwinia, and Corynebacterium have been used. (Urbance et al., 2001[11]; Sugisawa et al., 1990[12]; Sonoyamaet al., 1982[13]; Isono et al., 1968[14]). , In the second method mixture of cultures have been used by different researchers (Xu et al., 2004[15]; Nogami et al., 1987[16]), In this method they have used two stage fermentation process in which d-glucose is oxidized to 2,5-diketod-gluconate by Erwinia or Acetobacter strains in the first step while in second step 2,5-diketo-d-gluconate is converted in to 2-KLGA by a strain Corynebacterium. Sonoyama et al. (1982)[17] and in the third method genetically engineered strain have been used[10].