Human IL-1 receptor antagonist from Escherichia coli: Large-scale microbial growth and protein purification

1998 ◽  
Vol 64 (2-3) ◽  
pp. 187-196 ◽  
Author(s):  
Dino Zanette ◽  
William Dundon ◽  
Adolfo Soffientini ◽  
Cristina Sottani ◽  
Flavia Marinelli ◽  
...  
2014 ◽  
Vol 77 (2) ◽  
pp. 197-206 ◽  
Author(s):  
WENTING ZENG ◽  
KEITH VORST ◽  
WYATT BROWN ◽  
BRADLEY P. MARKS ◽  
SANGHYUP JEONG ◽  
...  

Temperature abuse during commercial transport and retail sale of leafy greens negatively impacts both microbial safety and product quality. Consequently, the effect of fluctuating temperatures on Escherichia coli O157:H7 and Listeria monocytogenes growth in commercially-bagged salad greens was assessed during transport, retail storage, and display. Over a 16-month period, a series of time-temperature profiles for bagged salads were obtained from five transportation routes covering four geographic regions (432 profiles), as well as during retail storage (4,867 profiles) and display (3,799 profiles). Five different time-temperature profiles collected during 2 to 3 days of transport, 1 and 3 days of retail storage, and 3 days of retail display were then duplicated in a programmable incubator to assess E. coli O157:H7 and L. monocytogenes growth in commercial bags of romaine lettuce mix. Microbial growth predictions using the Koseki-Isobe and McKellar-Delaquis models were validated by comparing the root mean square error (RMSE), bias, and the acceptable prediction zone between the laboratory growth data and model predictions. Monte Carlo simulations were performed to calculate the probability distribution of microbial growth from 8,122,127,472 scenarios during transport, cold room storage, and retail display. Using inoculated bags of retail salad, E. coli O157:H7 and L. monocytogenes populations increased a maximum of 3.1 and 3.0 log CFU/g at retail storage. Both models yielded acceptable RMSEs and biases within the acceptable prediction zone for E. coli O157:H7. Based on the simulation, both pathogens generally increased <2 log CFU/g during transport, storage, and display. However, retail storage duration can significantly impact pathogen growth. This large-scale U.S. study—the first using commercial time/temperature profiles to assess the microbial risk of leafy greens—should be useful in filling some of the data gaps in current risk assessments for leafy greens.


2021 ◽  
Vol 9 (2) ◽  
pp. 310
Author(s):  
Masayuki Hashimoto ◽  
Yi-Fen Ma ◽  
Sin-Tian Wang ◽  
Chang-Shi Chen ◽  
Ching-Hao Teng

Uropathogenic Escherichia coli (UPEC) is a major bacterial pathogen that causes urinary tract infections (UTIs). The mouse is an available UTI model for studying the pathogenicity; however, Caenorhabditis elegans represents as an alternative surrogate host with the capacity for high-throughput analysis. Then, we established a simple assay for a UPEC infection model with C. elegans for large-scale screening. A total of 133 clinically isolated E. coli strains, which included UTI-associated and fecal isolates, were applied to demonstrate the simple pathogenicity assay. From the screening, several virulence factors (VFs) involved with iron acquisition (chuA, fyuA, and irp2) were significantly associated with high pathogenicity. We then evaluated whether the VFs in UPEC were involved in the pathogenicity. Mutants of E. coli UTI89 with defective iron acquisition systems were applied to a solid killing assay with C. elegans. As a result, the survival rate of C. elegans fed with the mutants significantly increased compared to when fed with the parent strain. The results demonstrated, the simple assay with C. elegans was useful as a UPEC infectious model. To our knowledge, this is the first report of the involvement of iron acquisition in the pathogenicity of UPEC in a C. elegans model.


1982 ◽  
Vol 60 (12) ◽  
pp. 1143-1147 ◽  
Author(s):  
Harry W. Duckworth ◽  
Alexander W. Bell

Starting with a colicin E1 resistance recombinant plasmid which contains gltA, the gene for citrate synthase in Escherichia coli, we have constructed an ampicillin-resistance plasmid containing the gltA region as a 2.9-kilobase-pair insert in the tetracycline-resistance region of pBR322. Escherichia coli HB101 harbouring this plasmid, when grown on rich medium containing ampicillin, contains citrate synthase as about 8% of its soluble protein. The enzyme has been purified from this rich source and is identical to the chromosomal enzyme prepared previously in every property tested, except for specific activity, which is 64 U∙mg−1 as compared with 45–50 U∙mg−1 previously obtained. The N-terminal sequences of both enzymes are reported, and they are identical up to residue 16 at least. The overall yield of pure enzyme, starting with the cells grown in 15 L of medium, is 600–800 mg.


2021 ◽  
Vol 75 (1) ◽  
Author(s):  
Diego O. Serra ◽  
Regine Hengge

Biofilms are a widespread multicellular form of bacterial life. The spatial structure and emergent properties of these communities depend on a polymeric extracellular matrix architecture that is orders of magnitude larger than the cells that build it. Using as a model the wrinkly macrocolony biofilms of Escherichia coli, which contain amyloid curli fibers and phosphoethanolamine (pEtN)-modified cellulose as matrix components, we summarize here the structure, building, and function of this large-scale matrix architecture. Based on different sigma and other transcription factors as well as second messengers, the underlying regulatory network reflects the fundamental trade-off between growth and survival. It controls matrix production spatially in response to long-range chemical gradients, but it also generates distinct patterns of short-range matrix heterogeneity that are crucial for tissue-like elasticity and macroscopic morphogenesis. Overall, these biofilms confer protection and a potential for homeostasis, thereby reducing maintenance energy, which makes multicellularity an emergent property of life itself. Expected final online publication date for the Annual Review of Microbiology, Volume 75 is October 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.


PHARMACON ◽  
2019 ◽  
Vol 8 (1) ◽  
pp. 168
Author(s):  
Sitti N Tunggali ◽  
Herny E. I. Simbala ◽  
Henki Rotinsulu

ABSTRACT Sponge Aaptos aaptos is a marine biota that has great potential, which can be applied, in the pharmaceutical field because of the presence of large compounds in inhibiting microbial growth. This study aims to determine the inhibitory activity of extracts and fractions of sponge Aaptos aaptos on microbial growth of Escherichia coli, Staphylococcus aureus, and Candida albicans. The samples were extracted by maceration with 96 % ethanol and fractioned with n-hexane, choloroform and methanol. Testing is done using the Disc Diffusion Agar method. Crude ethanol extract and fraction of sponge Aaptos aaptos showed the greatest antimicrobial activity against Staphylococcus aureus and categorized as strong, with an average value of 20.32 mm for ethanol extract with strong categories, chloroform fraction 13,28 mm with medium category and methanol fractions 18,48 mm strong category. Keyword: Aaptos aaptos, antimicrobial activity, Escherichia coli, Staphylococcus aureus, Candida albicans.  ABSTRAK Spons Aaptos aaptos merupakan biota laut yang memiliki potensi sebagai antimikroba yang dapat diterapkan di bidang farmasi dengan kandungan senyawa yang besar dalam menghambat pertumbuhan mikroba. Penelitian ini bertujuan untuk mengetahui aktivitas daya hambat dari ekstrak dan fraksi spons Aaptos aaptos terhadap pertumbuhan mikroba Escherichia coli, Staphylococcus aureus, dan Candida albicans. Sampel diekstraksi secara maserasi dengan etanol dan difraksinasi dengan pelarut n–heksan, kloroform dan metanol. Pengujian dilakukan dengan menggunakan metode Disc Diffusion Agar. Ekstrak kasar etanol dan fraksi dari Spons Aaptos aaptos menunjukkan aktivitas antimikroba paling besar terhadap Staphylococcus aureus dan dikategorikan kuat, dengan nilai rata – rata 20,32 mm untuk ekstrak etanol dengan kategori kuat, fraksi kloroform 13,28 mm, kategori sedang dan fraksi metanol 18,48 mm kategori kuat.Kata Kunci : Aaptos aaptos, aktivitas antimikroba, Escherichia coli, Staphylococcus aureus, Candida albicans


2012 ◽  
Vol 05 (07) ◽  
pp. 406-408 ◽  
Author(s):  
Masahiro Sato ◽  
Eri Akasaka ◽  
Issei Saitoh ◽  
Masato Ohtsuka ◽  
Shingo Nakamura ◽  
...  
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