Construction of a Genetically Engineered Microorganism that Simultaneously Degrades Organochlorine and Organophosphate Pesticides

2011 ◽  
Vol 166 (3) ◽  
pp. 590-598 ◽  
Author(s):  
Jijian Yang ◽  
Ruihua Liu ◽  
Wenli Song ◽  
Yao Yang ◽  
Feng Cui ◽  
...  
Keyword(s):  
Genetically Engineered ◽  
Organophosphate Pesticides ◽  
Genetically Engineered Microorganism

Detection of Rhizobium meliloti cells in field soil and nodules by polymerase chain reaction

1995 ◽  
Vol 41 (9) ◽  
pp. 816-825 ◽  
Author(s):  
R. J. Watson ◽  
C. Haitas-Crockett ◽  
T. Martin ◽  
R. Heys
Keyword(s):  
Polymerase Chain Reaction ◽  
Rhizobium Meliloti ◽  
Genetically Engineered ◽  
Chain Reaction ◽  
Pcr Inhibitor ◽  
Vertical Location ◽  
Meliloti Strain ◽  
Identification Of Bacteria ◽  
Polymerase Chain ◽  
Genetically Engineered Microorganism

A genetically marked Rhizobium meliloti strain, R692, was prepared by insertion of a 1.7-kb DNA segment from Tn903 between the nifHDK and fixABC genes in the nod megaplasmid. This DNA was used as a marker, detectable by polymerase chain reaction (PCR), for the specific identification of bacteria in soil samples and alfalfa nodules. This detection technique was tested by applying different titres of the marked strain to field plots seeded with alfalfa. Samples of soil and nodules were assayed for the presence of the marker DNA fragment by PCR using primers specific to the marker sequence. The experiments revealed that the bacteria could be detected directly in soil containing about 103–104 bacteria/g, but greater sensitivity was prevented by potent PCR inhibitors present in the samples. The titre of the bacteria in the soil decreased rapidly after inoculation, dropping about 10-fold per week. Tests of vertical location of the bacteria in soil cores showed that the bacteria were initially dispersed to a depth of 18 cm, and subsequently retained viability in the top 2–8 cm. As few as 10 marked R. meliloti per gram of soil resulted in its establishment at detectable levels in nodules. Application of about 104–105 bacteria/g soil was sufficient to give the maximum number of nodules per plant and resulted in 70–90% occupancy by the marked strain. Limited movement of the inoculant was detected by analysis of nodules from plants adjacent to the sites where the bacteria were applied, probably by movement in water. The experiments demonstrated the advantages of PCR for the monitoring of marked microorganisms in the environment.Key words: genetically engineered microorganism, PCR inhibitor, nitrogen fixation, nif and fix genes, genetic marker.

Recovery of a rhizosphere-colonizing GEM from inside wheat roots

1999 ◽  
Vol 45 (7) ◽  
pp. 612-615 ◽  
Author(s):  
James D Nairn ◽  
Christopher P Chanway
Keyword(s):  
Rhizosphere Soil ◽  
Genetically Engineered ◽  
Root Tissue ◽  
Marker Genes ◽  
Wheat Roots ◽  
Genetically Engineered Microorganisms ◽  
Population Sizes ◽  
Genetically Engineered Microorganism ◽  
Root Tissues ◽  
Fresh Root

Pseudomonas chloroaphis 3732 RN-L11 is a genetically modified bacterial strain that contains the lacZY marker genes in its chromosome. This strain is known to be a vigorous colonizer of plant roots and rhizosphere soil, and has been used as a model to evaluate survival and persistence of field-released genetically engineered microorganisms (GEMs). However, the possibility that strain 3732 RN-L11 may also colonize internal plant tissues has not previously been investigated. Using spring wheat as a model system, we studied the ability of strain 3732 RN-L11 to colonize external and internal root tissues after seed inoculation. Strain 3732 RN-L11 was recovered from rhizosphere soil of 28-, 42-, and 56-day-old seedlings with mean population sizes of 3.3 × 105, 7.5 × 104, and 2.2 × 105CFU·g-1fresh root tissue, respectively. In addition, this strain was consistently recovered from surface-sterilized root tissues of 28- to 56-day-old seedlings with mean population sizes of 1.0 × 102to 6.2 × 103CFU·g-1fresh root tissue. Our results indicate that evaluation of plant-associated GEM populations after field release should include all possible colonization niches, including internal plant tissues.Key words: genetically engineered microorganism, rhizosphere, endophyte.

scholarly journals Bio-based 3-hydroxypropionic Acid: A Review

2017 ◽  
Vol 62 (2) ◽  
pp. 156 ◽  
Author(s):  
Aladár Vidra ◽  
Áron Németh
Keyword(s):  
Metabolic Engineering ◽  
Acrylic Acid ◽  
Methyl Acrylate ◽  
Metabolic Pathways ◽  
Commercial Production ◽  
Genetically Engineered ◽  
High Yield ◽  
Biochemical Pathways ◽  
Genetically Engineered Microorganism ◽  
Hydroxypropionic Acid

3-hydroxypropionic acid is a commercially valuable, important platform chemical. It can serve as a precursor for several key compound, such as acrylic acid, 1,3-propanediol, methyl acrylate, acrylamide, ethyl 3-HP, malonic acid, propiolactone and acrylonitrile. Several microorganisms can produce through a range of metabolic pathways. It is indispensable for the commercial production of 3-HP to use cheap and abundant substrates and also to produce in highly efficient processes which could result high yield, titer and productivity. Because  of the fact, that natural microorganism do not perform these conditions, metabolic engineering and genetically engineered microorganism are widely used for research and production as well. Several metabolic pathways are introduced to utilize glucose or glycerol for 3-HP production. In this overview naturally producer microorganisms, synthetic biochemical pathways, results from the recent years and recovery of 3-HP are detailed.

Sign in / Sign up

Export Citation Format

Share Document