Alkaline protease production using a membrane bioreactor

2005 ◽  
Author(s):  
◽  
Nolene Haricharan
Keyword(s):  
Alkaline Protease ◽  
Biofilm Formation ◽  
Membrane Bioreactor ◽  
Sclerotium Rolfsii ◽  
Test Organism ◽  
Initial Step ◽  
Thermomyces Lanuginosus ◽  
Protease Production ◽  
E Coli ◽  
Effluent Sample

Alkaline proteases are an important class of industrial enzymes that are mainly used in detergents, and also in industries like leather, food, photography and pharmaceuticals. Most industrial processes use submerged fermentation (SMF) for alkaline protease production. Recently, solid state fermentation (SSP) has been used. This research presents the potential of an additional process for alkaline protease production, namely membrane bioreactor (MBR) system. lts application has been extended from ultrafitration operation to a potential enzyme production system. This research is therefore based on the evaluation of skinless polysulphone capillary membrane for the production of enzymes. The initial step in this project involved the experimental determination of the most suitable test organism for immobilization and biofilm formation on the membrane. This involved the use of a flow-cell chamber system with strains of Thermomyces lanuginosus ATCC 38905, T. lanuginosus ATCC 46882, Cryptococus laurentii, Aspergillus aculeatus DSM 2344, Gliocladium roseum, Penicillium grabrum, P. chrysogenum CCRC 31619, P. italicium, Saccharomyces cerevisiae, E. coli B8, Sclerotium rolfsii and a winery effluent sample comprising of a consortium of unidentified bacteria. Biofilm formation on the surface was observed visually over a period of seven days, while immobilization of the organism within the microvoids was observed microscopically using fluorescent and electron microscopy. Experimental data provided evidence that the T. lanuginosus strains ATCC 38905 and ATCC 46882, A. aculeatus DSM 2344, S. cerevisiae, E. coli and S. rolfsii were poor biofilm producers and did not demonstrate the ability to immobilize onto the membrane. G. roseum, P. glabrum, P. chrysogenum CCRC 31619, P. italicium, C. laurentii and the effluent sample were adequate biofilm producers with the ability to immobilize onto the membrane. The alkaline protease producing strain of P. chrysogenum CCRC 31619 was chosen for use for the next phase of this research.

scholarly journals Genotypic and phenotypic characteristics associated with biofilm formation in Escherichia coli and Salmonella spp. isolated from ulam in Terengganu

Food Research ◽  
2019 ◽  
Vol 4 (1) ◽  
pp. 91-101
Author(s):  
Anis, A. Bahri ◽  
Wan Zawiah Wan Abdullah ◽  
Mohd Nizam Lani ◽  
W. Salleh ◽  
Rozila Alias
Keyword(s):  
Escherichia Coli ◽  
Disease Transmission ◽  
Congo Red ◽  
Biofilm Formation ◽  
Initial Step ◽  
Bacterial Attachment ◽  
Salmonella Spp ◽  
Pellicle Formation ◽  
E Coli ◽  
Fresh Vegetables

Nowadays, the foodborne outbreaks associated with fresh produces, including ulam, are increasing worldwide. The biofilm formation or bacterial attachment to plant surface is the initial step towards the contamination in fresh produce. The biofilm phenotype of bacteria grown on congo red agar is termed as red, dry and rough (rdar) morphotype. The binding of congo red dye with both biological proteins and inert surfaces is due to the presence of curli fimbriae and cellulose as the main extracellular components. The objective of this study was to determine the rdar morphotypes, biofilm ability and the role of csgA gene of Escherichia coli and Salmonella spp. isolated from ulam or Malaysian herbs. A total of 29 isolates, including 23 E. coli and 6 Salmonella spp. were analyzed for their ability to produce biofilm by colony morphology test, microtiter plate biofilm assay and qualitative biofilm test (pellicle formation). The presence of the csgA gene of E. coli was identified by PCR, which demonstrated the potential gene that able to produce curli fimbriae. Results revealed that 16 (69.6%) E. coli isolates were categorized as strong biofilm producers, 2 (8.7%) as moderate biofilm producers, 3 (13%) as weak biofilm producers, whereas 2 (8.7%) as negative biofilm producers (did not produce biofilm). While 4 (66.7%) Salmonella spp. isolates were identified as strong biofilm producers, 1 (16.7%) as moderate biofilm producers and 1 (16.7%) as negative biofilm producers. Majority of the E. coli strains (69.6%) were identified as strong biofilm producers and able to express rdar morphotypes. The ability of the of E. coli and Salmonella spp. isolates to form biofilm reveals the ability of these isolates to persist on the fresh vegetables and become hosts for the disease transmission to humans or/and animals.

scholarly journals Label-free quantitative proteomic analysis of the inhibition effect of Lactobacillus rhamnosus GG on Escherichia coli biofilm formation in co-culture

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Huiyi Song ◽  
Ni Lou ◽  
Jianjun Liu ◽  
Hong Xiang ◽  
Dong Shang
Keyword(s):  
Escherichia Coli ◽  
Proteomic Analysis ◽  
Biofilm Formation ◽  
Lactobacillus Rhamnosus ◽  
Differentially Expressed ◽  
Differentially Expressed Proteins ◽  
Label Free ◽  
Quantitative Proteomic Analysis ◽  
E Coli ◽  
Protein Ubiquitination

Abstract Background Escherichia coli (E. coli) is the principal pathogen that causes biofilm formation. Biofilms are associated with infectious diseases and antibiotic resistance. This study employed proteomic analysis to identify differentially expressed proteins after coculture of E. coli with Lactobacillus rhamnosus GG (LGG) microcapsules. Methods To explore the relevant protein abundance changes after E. coli and LGG coculture, label-free quantitative proteomic analysis and qRT-PCR were applied to E. coli and LGG microcapsule groups before and after coculture, respectively. Results The proteomic analysis characterised a total of 1655 proteins in E. coli K12MG1655 and 1431 proteins in the LGG. After coculture treatment, there were 262 differentially expressed proteins in E. coli and 291 in LGG. Gene ontology analysis showed that the differentially expressed proteins were mainly related to cellular metabolism, the stress response, transcription and the cell membrane. A protein interaction network and Kyoto Encyclopaedia of Genes and Genomes (KEGG) pathway analysis indicated that the differentiated proteins were mainly involved in the protein ubiquitination pathway and mitochondrial dysfunction. Conclusions These findings indicated that LGG microcapsules may inhibit E. coli biofilm formation by disrupting metabolic processes, particularly in relation to energy metabolism and stimulus responses, both of which are critical for the growth of LGG. Together, these findings increase our understanding of the interactions between bacteria under coculture conditions.

scholarly journals Antimicrobial and Immunomodulating Activities of Two Endemic Nepeta Species and Their Major Iridoids Isolated from Natural Sources

2021 ◽  
Vol 14 (5) ◽  
pp. 414
Author(s):  
Neda Aničić ◽  
Uroš Gašić ◽  
Feng Lu ◽  
Ana Ćirić ◽  
Marija Ivanov ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Food Industry ◽  
Balkan Peninsula ◽  
Antimicrobial Activities ◽  
Natural Sources ◽  
E Coli ◽  
Food Borne ◽  
Metabolite Profiles ◽  
Aspergillus Sp ◽  
First Time

Two Balkan Peninsula endemics, Nepeta rtanjensis and N. argolica subsp. argolica, both characterized by specialized metabolite profiles predominated by iridoids and phenolics, are differentiated according to the stereochemistry of major iridoid aglycone nepetalactone (NL). For the first time, the present study provides a comparative analysis of antimicrobial and immunomodulating activities of the two Nepeta species and their major iridoids isolated from natural sources—cis,trans-NL, trans,cis-NL, and 1,5,9-epideoxyloganic acid (1,5,9-eDLA), as well as of phenolic acid rosmarinic acid (RA). Methanol extracts and pure iridoids displayed excellent antimicrobial activity against eight strains of bacteria and seven strains of fungi. They were especially potent against food-borne pathogens such as L. monocytogenes, E. coli, S. aureus, Penicillium sp., and Aspergillus sp. Targeted iridoids were efficient agents in preventing biofilm formation of resistant P. aeruginosa strain, and they displayed additive antimicrobial interaction. Iridoids are, to a great extent, responsible for the prominent antimicrobial activities of the two Nepeta species, although are probably minor contributors to the moderate immunomodulatory effects. The analyzed iridoids and RA, individually or in mixtures, have the potential to be used in the pharmaceutical industry as potent antimicrobials, and in the food industry to increase the shelf life and safety of food products.

scholarly journals Bioactive constituents with antibacterial, resistance modulation, anti-biofilm formation and efflux pump inhibition properties from Aidia genipiflora stem bark

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Daniel Anokwah ◽  
Evelyn Asante-Kwatia ◽  
Abraham Y. Mensah ◽  
Cynthia Amaning Danquah ◽  
Benjamin K. Harley ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Efflux Pump ◽  
Ethyl Acetate Fraction ◽  
Stem Bark ◽  
Resistance Mechanisms ◽  
Bioactive Constituents ◽  
Biofilm Inhibition ◽  
E Coli ◽  
Efflux Pump Inhibition ◽  
Oleanonic Acid

Abstract Background Antimicrobial resistance is a global health challenge. The involvement of bacterial biofilms and efflux pumps in the development of multidrug resistance (MDR) is well established. Medicinal plants have been proposed as alternatives for combating MDR focusing on their bioactive constituents with resistance modulatory activities. This study was aimed at investigating the stem bark of Aidia genipiflora for bioactive constituents with anti-biofilm, efflux pump inhibition and resistance modulatory activities. Method The crude methanol extract was purified by column chromatography and isolated compounds characterized by mass and nuclear magnetic resonance spectrometry. Antibacterial activity was determined by the High-throughput spot culture growth inhibition and the broth micro-dilution assay. The ethidium bromide accumulation assay was used to determine efflux pump inhibition property. Biofilm inhibition was determined in a microplate crystal violet retention assay. Results Purification of the ethyl acetate fraction led to the isolation of oleanonic acid (1), 4-hydroxy cinnamic acid docosyl ester (2), β-stigmasterol/β-sitosterol (mixture 3a/b) and D-mannitol (4). The minimum inhibitory concentrations (MICs) ranged from 250 to > 500 μg/mL for extracts and fractions and from 15 to 250 μg/mL for compounds. In the presence of sub-inhibitory concentrations of the compounds, the MIC of amoxicillin against E. coli (20 μg/mL) and P. aeruginosa (320 μg/mL) was reduced by 32 and 10 folds respectively. The whole extract demonstrated anti-biofilm formation and efflux pump inhibition in E. coli, S. aureus and P. aeruginosa. The sterol mixture (3a/b) at concentration of 100 μg/mL caused the highest inhibition (73%) of biofilm formation in S. aureus. Oleanonic acid (1) demonstrated remarkable efflux pump inhibition at MIC of 7.8 μg/mL in E. coli better than the standard drugs verapamil and chlorpromazine. Conclusion This study confirms the prospects of A. genipiflora as a source of new antibacterial agents and adjuvants that could interact with some resistance mechanisms in bacteria to enhance the activity of hitherto ineffective antibiotics. “A small portion of the study has been presented in a conference in the form of poster”.

Metabolic flux analyses for serine alkaline protease production

2000 ◽  
Vol 27 (10) ◽  
pp. 793-805 ◽  
Author(s):  
Pınar Çalik ◽  
Güzide Çalik ◽  
Serpil Takaç ◽  
Tunçer H Özdamar
Keyword(s):  
Alkaline Protease ◽  
Metabolic Flux ◽  
Protease Production ◽  
Serine Alkaline Protease

Influence of Glucose Concentrations on Biofilm Formation, Motility, Exoprotease Production, and Quorum Sensing in Aeromonas hydrophila

2013 ◽  
Vol 76 (2) ◽  
pp. 239-247 ◽  
Author(s):  
IQBAL KABIR JAHID ◽  
NA-YOUNG LEE ◽  
ANNA KIM ◽  
SANG-DO HA
Keyword(s):  
Quorum Sensing ◽  
Aeromonas Hydrophila ◽  
Biofilm Formation ◽  
Opportunistic Pathogen ◽  
Homoserine Lactone ◽  
Protease Production ◽  
Acyl Homoserine Lactone ◽  
Human Pathogen ◽  
Initial Biofilm ◽  
Motility Inhibition

Aeromonas hydrophila recently has received increased attention because it is opportunistic and a primary human pathogen. A. hydrophila biofilm formation and its control are a major concern for food safety because biofilms are related to virulence. Therefore, we investigated biofilm formation, motility inhibition, quorum sensing, and exoprotease production of this opportunistic pathogen in response to various glucose concentrations from 0.05 to 2.5% (wt/vol). More than 0.05% glucose significantly impaired (P < 0.05) quorum sensing, biofilm formation, protease production, and swarming and swimming motility, whereas bacteria treated with 0.05% glucose had activity similar to that of the control (0% glucose). A stage shift biofilm assay revealed that the addition of glucose (2.5%) inhibited initial biofilm formation but not later stages. However, addition of quorum sensing molecules N-3-butanoyl-DL-homoserine lactone and N-3-hexanoyl homoserine lactone partially restored protease production, indicating that quorum sensing is controlled by glucose concentrations. Thus, glucose present in food or added as a preservative could regulate acyl-homoserine lactone quorum sensing molecules, which mediate biofilm formation and virulence in A. hydrophila.

PBP4 and PBP5 are involved in regulating exopolysaccharide synthesis during Escherichia coli biofilm formation

Microbiology ◽  
2021 ◽  
Vol 167 (3) ◽  
Author(s):  
Sathi Mallick ◽  
Shanti Kiran ◽  
Tapas Kumar Maiti ◽  
Anindya S. Ghosh
Keyword(s):  
Escherichia Coli ◽  
Biofilm Formation ◽  
Type Species ◽  
Pentose Phosphate ◽  
Bacterial Cells ◽  
Surface Adhesion ◽  
Content Type ◽  
Penicillin Binding Proteins ◽  
E Coli ◽  
Link Type

Escherichia coli low-molecular-mass (LMM) Penicillin-binding proteins (PBPs) help in hydrolysing the peptidoglycan fragments from their cell wall and recycling them back into the growing peptidoglycan matrix, in addition to their reported involvement in biofilm formation. Biofilms are external slime layers of extra-polymeric substances that sessile bacterial cells secrete to form a habitable niche for themselves. Here, we hypothesize the involvement of Escherichia coli LMM PBPs in regulating the nature of exopolysaccharides (EPS) prevailing in its extra-polymeric substances during biofilm formation. Therefore, this study includes the assessment of physiological characteristics of E. coli CS109 LMM PBP deletion mutants to address biofilm formation abilities, viability and surface adhesion. Finally, EPS from parent CS109 and its ΔPBP4 and ΔPBP5 mutants were purified and analysed for sugars present. Deletions of LMM PBP reduced biofilm formation, bacterial adhesion and their viability in biofilms. Deletions also diminished EPS production by ΔPBP4 and ΔPBP5 mutants, purification of which suggested an increased overall negative charge compared with their parent. Also, EPS analyses from both mutants revealed the appearance of an unusual sugar, xylose, that was absent in CS109. Accordingly, the reason for reduced biofilm formation in LMM PBP mutants may be speculated as the subsequent production of xylitol and a hindrance in the standard flow of the pentose phosphate pathway.

scholarly journals Biofilm Formation of a Polymer Brush Coating with Ionic Liquids Compared to a Polymer Brush Coating with a Non-Ionic Liquid

Coatings ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 398 ◽  
Author(s):  
Hideyuki Kanematsu ◽  
Atsuya Oizumi ◽  
Takaya Sato ◽  
Toshio Kamijo ◽  
Saika Honma ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Ionic Liquids ◽  
Polymethyl Methacrylate ◽  
Biofilm Formation ◽  
Polymer Brush ◽  
E Coli ◽  
Glass Substrates ◽  
Liquid Type ◽  
Brush Coating

N,N-diethyl-N-(2-methancryloylethy)-N-methylammonium bis(trifluoromethylsulfonyl) imide polymer (DEMM-TFSI) brush coated specimens (substrate: glasses) and a liquid ion type of polymer brush coating were investigated for their antifouling effect on biofilms. Biofilms were produced by two kinds of bacteria, E. coli and S. epidermidis. They were formed on specimens immersed into wells (of 12-well plates) that were filled with culture liquids and bacteria. The biofilm formation was observed. Also, brush coated specimens and glass substrates were investigated in the same way. DEMM polymer brush coated specimens formed more biofilm than PMMA (polymethyl methacrylate) polymer brush coated specimens and glass substrates. A greater amount of polarized components of biofilms was also observed for DEMM polymer brush coated specimens. The polar characteristics could be attributed to the attraction capability of bacteria and biofilms on DEMM polymer brush coated specimens. When considering the ease of removing biofilms by washing it with water, the ionic liquid type polymer brush (coated specimens) could be used for antifouling applications. If an initial antifouling application is needed, then the polar characteristics could be adjusted (design of the components and concentrations of ionic liquids, etc.) to solve the problem.

Reduction of Microorganisms on Citrus Fruit Surfaces during Packinghouse Processing

1998 ◽  
Vol 61 (7) ◽  
pp. 903-906 ◽  
Author(s):  
STEVEN PAO ◽  
G. ELDON BROWN
Keyword(s):  
Test Organism ◽  
Citrus Fruit ◽  
Microbial Populations ◽  
Most Probable Number ◽  
Probable Number ◽  
E Coli ◽  
Plate Counts ◽  
High Level ◽  
Inoculation Study ◽  
Fruit Surface

Citrus fruit surface microbial populations were evaluated following various packingline processes of seven Florida commercial packinghouses. At each packinghouse, six fruits (oranges or tangerines) were collected at each of four sampling points. The sampling was conducted in duplicate; thus, 336 fruit were evaluated during this survey. Average aerobic plate counts and yeast and mold counts on fruit surfaces before washing were about 4.0 log CFU/cm2 and 3.3 log CFU/cm2, respectively, and were reduced to 2.1 log CFU/cm2 and 1.3 log CFU/cm2, respectively, by packinghouse processing. Waxing alone reduced the average fruit surface aerobic plate counts and coliform counts from 3.7 log CFU/cm2 and 35.2 most probable number (MPN)/cm2, respectively, to 2.6 log CFU/cm2 and 1.4 MPN/cm2. No Escherichia coli was recovered from fruit at the end of packinghouse processing, and no salmonellae were found on fruit during the entire processing. In an inoculation study to test the effect of packinghouse processes, test organism E. coli was applied to fruit to achieve a high level (4.8 log CFU/cm2) of contamination. The average E. coli count was reduced about 2.4 log cycles by washing and rinsing with potable water (40 psi, 25 °C) for about 30 s. The combination of washing and waxing significantly reduced the inoculated level of E. coli from 4.8 to 1.4 log CFU/cm2.

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