Wild type Cupriavidus necator H16 (ATCC 17699) [formerly known as Wautersia eutropha] was used throughout this study. The bacterium was maintained on Nutrient-Rich(NR) agar containing 2 g/L yeast extract, 10 g/L meat extract, 10 g/L peptone and 14 g/3 bacteriological agar powder (Doi et al., 1995).
PHA Biosynthesis in 100 L Fermenter
PHA biosynthesis was carried out with one-stage fed-batch cultivation in 100 L fermenter. The temperature for this whole experiment was maintained at 30 °C. Starter culture was prepared by inoculating two loopfuls of bacteria cells into 50 mL NR broth and cultivated at 200 rpm at 30 °C. Approximately 1.5 mL (3 % v/v) of the starter culture was inoculated into 7 flasks containing 100 mL NR medium each after 7 h incubation (OD600nm = 5.0). The seed culture of 700 mL was transferred into 6.3 L of fresh NR in a 10 L fermenter ( Labfors, Infors, Switzerland) upon the growth of bacteria cells entered the mid-exponential phase. To initiate PHA biosynthesis, 7 L of the preculture was inoculated into 63 L of MM (Doi et al., 1995) in a 100 L fermenter (Biostat, Germany) after approximately 12 h of cultivation. The agitation rate was increased from 200 to 500 rpm to maintain the level of dissolved O2 at 40 % saturation and the pH was adjusted to 7.0 by using 3 M NaOH. Crude palm kernel oil (CPKO) supplied by Acidchem Int. Ltd. was fed as sole carbon source for P(3HB) production at a maximum concentration of 46 g/L. After 48 h of cultivation, cells were harvested by centrifugation (9370 × g for 5 min) at 4° C. The pellets were then frozen at – 20 °C for 24 h before freeze-drying at 40 oC for three days.
Biological Recovery of PHA
... middle of paper ...
...e determined from the DSC endotherm.
Thermogravimetric Analysis (TGA)
The thermal analysis was carried out using Mettler Toledo Star System. Sample was heated from 50 to 900 °C under a nitrogen atmosphere.
Nuclear Magnetic Resonance (NMR)
The chemical structure of recovered PHA was determined by NMR spectroscopy at 400 MHz 1H and 300 MHz 13C scans. Approximately 15 mg sample was dissolved in 1 mL of deuterated chloroform (CDCl3). C. Tetramethylsilane (Me4Si) was used as an internal chemical shift reference.
Scanning Electron Microscope (SEM)
The lyophilized cells and powdered faeces samples were subjected to SEM observation. The samples were mounted on aluminium stubs, sputter-coated with gold for 15 seconds prior to observation under Leo Supra 50 VP Field Emission SEM at an acceleration voltage of 10 kV and magnification of 1000 – 50,000 times.
Need Writing Help?
Get feedback on grammar, clarity, concision and logic instantly.Check your paper »
- Bacterial Strains, Plasmids, and Standard Media Bacterial strain which was used as a host for recombinant plasmid propagation was E. coli DH5 α, whereas for subcloning and expression was B. subtilis DB104 ; Plasmid used in this experiment was pSKE194 an E.coli-Bacillus shuttle vector (both bacterial strain and plasmid were precious gift from Prof Meinhardt, Muenster University). For regenerating Bacillus protoplasts containing desired recombinant plasmid the 1.5% (w/v) agar containing regeneration medium DM3 was used (Chang and Cohen 1984), and for selection of positive Bacillus transformant, LB medium containing erythromycin 5 µg mL-1 were used.... [tags: Bacteria, Escherichia coli, Enzyme, DNA]
1076 words (3.1 pages)
- Introduction Bacterial vaginosis is known to be the most common cause of abnormal vaginal discharge in women of childbearing age (Hay, 2010). Bacterial vaginosis is the result of the substitution of normal vaginal lactobacilli with anaerobic bacteria Gardnerella vaginalis and Prevotella, Peptostreptococcus and Bacteroides spp., which will result loss of the normal vaginal acidity (Turovskiy, Sutyak Noll, & Chikindas, 2010). Bacterial vaginosis is the main trigger of vaginal discharge or malodor in women (Hainer & Gibson, 2011).... [tags: abnormal vaginal discharge]
1624 words (4.6 pages)
- Specific Aims: In the United States, it is estimated that 63% of cases are solved, however that leaves 37% that are left unsolved. In violent crimes alone, the U.S. suffered over 1 million cases, of which almost half were left cold (FBI, 2010). A number of unsolved cases remain that way because of the lack of evidence, such as DNA at the crime scene. I intend to use the bacterial strains found in bite marks of victims to match the marks to the biter by comparing the strains found in each location.... [tags: Criminal Justice]
1815 words (5.2 pages)
- Bacterial polyhydroxyalkanote (PHA) is a good candidate to replace synthetic plastic due to its biodegradability. The main factor that hampered the commercialization of PHA is the high production cost with the recovery processes accounting for the most. The present study suggests a novel biological recovery method of polyhydroxybutyrate (PHB) from Cupriavidus necator H16. The PHA granules have been extracted without the help of any solvent or chemicals. The lyophilized cells were used protein source for the laboratory rats and simultaneously recovered the PHB granules excreted in the faeces.... [tags: Biotechnology]
2359 words (6.7 pages)
- ... meliloti symbiosis. 2. The authors posit that both partner choice and sanctions exists in Medicago truncatula-Sinorhizobium meliloti symbiosis because M. truncatula selects the S. meliloti and mutualistic individuals are rewarded while the non-mutualistic ones are sanctioned. 3. In order to investigate the existence of partner choice and sanctions, the M. truncatula fixed line F83-005 was grown under with two different S. meliloti strain: non-nitrogen-fixing strain (STM 5472) and nitrogen-fixing strain (STM 5480).... [tags: nodules, partners, strain]
850 words (2.4 pages)
- Microbial world frequently face abrupt changes in the surrounding environment. For the survival in such a dynamic environment, it is advantageous to take decision of future action at the population level. Bacteria do so by a phenomenon called quorum sensing (QS), which is sensing the presence of other bacteria in surrounding environment, and taking the decision at certain threshold cell density. In QS active state, bacteria induces certain set of target genes at population level. QS among bacteria is mediated by autoinducers (AIs), whose concentration is a function of cell density, and above a certain concentration of cells AI mediate QS.... [tags: germs, strain, dna]
1361 words (3.9 pages)
- Introduction About 90% of bacteria live in biofilms communities. The biofilm is very important, especially in pathogenic bacteria such as Bacillus spp, Streptococcus spp, Enterococcus spp, and Pseudomonas spp. Prevent formation of biofilm unknown until now, but there are a lot of studies talked about this problem.There are many mechanisms to formation biofilm in bacteria and it help to formation microbial cluster, thus spread of microbs. In this review I 'll search about Prevent formation of bacterial biofilm via breakdown Nitric Oxide (NO) cycle.... [tags: Bacteria, Microbiology, Biofilm]
1410 words (4 pages)
- Confirmation of Bacterial Transformation and DNA as the Inducing Material Confirmation of Transformation and DNA as the Inducing Material Introduction The experiments in this report are a recreation the famous Griffith and Avery experiments which discovered the transformation process that bacteria can undertake and that DNA is the genetic material, respectively (Griffth, 1928. Avery 1944). Bacteria can incorporate foreign DNA found in their medium into their genomes in a process known as transformation.... [tags: genetic studies and experiments]
1042 words (3 pages)
- What is a disease you may ask yourself at first. Disease can be defined in many ways, but a common definition would be any impairment that would interfere or modify normal functions, with responses to factors such as nutrition, infectious agents, defects, or toxicants (Wobeser 1997). Disease outbreaks follow a simple three way path that involves a host, agent, and the environment. Wide arrays of avian diseases are found throughout the bird world, but much is still unknown about them. According to Karstad, “disease in wildlife populations is rarely a one-cause, one-effect situation.... [tags: Waterfowl, Bacteria Strain]
1865 words (5.3 pages)
- Bacterial Conjugation Experiment INTRODUCTION: Bacteria, in general, reproduce asexually, but in order to increase diversity, they have developed a mechanism for transfer of genetic material from one bacterium to another. The ability to perform this transfer is conferred by a set of genes which are called F for 'fertility.' These genes exist on a small, circular piece of deoxyribonucleic acid (DNA) that replicates independently from the bacterial chromosome, or they can be integrated into the chromosome.... [tags: Papers]
950 words (2.7 pages)