Tailor‐made alginate? Investigations of biotechnological alginate production with Azotobacter vinelandii

2020 ◽  
Vol 92 (9) ◽  
pp. 1198-1198
Author(s):  
S. Stachurski ◽  
H. Salgado-Lugo ◽  
C. F. Peña Malacara ◽  
J. Büchs
Keyword(s):  
Azotobacter Vinelandii ◽  
Alginate Production

scholarly journals The algT Gene of Pseudomonas syringae pv. glycinea andNew Insights into the Transcriptional Organization of thealgT-muc Gene Cluster

2006 ◽  
Vol 188 (23) ◽  
pp. 8013-8021 ◽  
Author(s):  
Alexander Schenk ◽  
Michael Berger ◽  
Lisa M. Keith ◽  
Carol L. Bender ◽  
Georgi Muskhelishvili ◽  
...  
Keyword(s):  
Gene Cluster ◽  
Pseudomonas Syringae ◽  
Azotobacter Vinelandii ◽  
Regulatory Gene ◽  
In Planta ◽  
Phytopathogenic Bacterium ◽  
Reverse Transcription Pcr ◽  
Alginate Production ◽  
Alginate Biosynthesis

ABSTRACT The phytopathogenic bacterium Pseudomonas syringae pv. glycinea infects soybean plants and causes bacterial blight. In addition to P. syringae, the human pathogen Pseudomonas aeruginosa and the soil bacterium Azotobacter vinelandii produce the exopolysaccharide alginate, a copolymer of d-mannuronic and l-guluronic acids. Alginate production in P. syringae has been associated with increased fitness and virulence in planta. Alginate biosynthesis is tightly controlled by proteins encoded by the algT-muc regulatory gene cluster in P. aeruginosa and A. vinelandii. These genes encode the alternative sigma factor AlgT (σ22), its anti-sigma factors MucA and MucB, MucC, a protein with a controversial function that is absent in P. syringae, and MucD, a periplasmic serine protease and homolog of HtrA in Escherichia coli. We compared an alginate-deficient algT mutant of P. syringae pv. glycinea with an alginate-producing derivative in which algT is intact. The alginate-producing derivative grew significantly slower in vitro growth but showed increased epiphytic fitness and better symptom development in planta. Evaluation of expression levels for algT, mucA, mucB, mucD, and algD, which encodes an alginate biosynthesis gene, showed that mucD transcription is not dependent on AlgT in P. syringae in vitro. Promoter mapping using primer extension experiments confirmed this finding. Results of reverse transcription-PCR demonstrated that algT, mucA, and mucB are cotranscribed as an operon in P. syringae. Northern blot analysis revealed that mucD was expressed as a 1.75-kb monocistronic mRNA in P. syringae.

Alginate production by Azotobacter vinelandii DSM576 in batch fermentation

1998 ◽  
Vol 20 (3-4) ◽  
pp. 171-176 ◽  
Author(s):  
E Parente ◽  
M A Crudele ◽  
M Aquino ◽  
F Clementi
Keyword(s):  
Batch Fermentation ◽  
Azotobacter Vinelandii ◽  
Alginate Production

Alginate production by Azotobacter vinelandii in a membrane bioreactor

2002 ◽  
Vol 38 (2) ◽  
pp. 273-278 ◽  
Author(s):  
N Saude ◽  
H Chèze-Lange ◽  
D Beunard ◽  
P Dhulster ◽  
D Guillochon ◽  
...  
Keyword(s):  
Membrane Bioreactor ◽  
Azotobacter Vinelandii ◽  
Alginate Production

scholarly journals The GacS Sensor Kinase Regulates Alginate and Poly-β-Hydroxybutyrate Production in Azotobacter vinelandii

2000 ◽  
Vol 182 (9) ◽  
pp. 2624-2628 ◽  
Author(s):  
Miguel Castañeda ◽  
Josefina Guzmán ◽  
Soledad Moreno ◽  
Guadalupe Espín
Keyword(s):  
Biosynthetic Pathway ◽  
Azotobacter Vinelandii ◽  
Response Regulator ◽  
Extracellular Polysaccharide ◽  
Predicted Amino Acid Sequence ◽  
Sensor Kinase ◽  
Alginate Production ◽  
Gene Coding ◽  
Key Enzyme ◽  
Cognate Response Regulator

ABSTRACT Azotobacter vinelandii produces two polymers: the extracellular polysaccharide alginate and the intracellular polyester poly-β-hydroxybutyrate (PHB). A cosmid clone (pSMU588) from anA. vinelandii gene library diminished alginate production by A. vinelandii mucoid strain ATCC 9046. The nucleotide sequence and predicted amino acid sequence of the locus responsible for the mucoidy suppression revealed 65% identity toPseudomonas GacS, a transmembrane sensor kinase of the two-component regulators, whose cognate response regulator, GacA, is a global activator regulating several products and virulence factors. Plasmid pMC15, harboring gacS, and a strain carrying agacS nonpolar mutation were constructed. Either pMC15 or the gacS mutation significantly reduced alginate production and transcription of algD, the gene coding for the key enzyme GDP-mannose dehydrogenase of the alginate biosynthetic pathway. We found that the gacS mutation also reduced PHB accumulation and impaired encystment. Taken together, these data indicate that in A. vinelandii the gacSA global system regulates polymer synthesis.

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