scholarly journals Screening of microorganisms for hydrolyases with commercial potential

2022 ◽  
Vol 13 (1) ◽  
pp. 092-101
Author(s):  
Jay N Patel ◽  
Fenil A Parmar ◽  
Vivek N Upasani
Keyword(s):  
Staphylococcus Aureus ◽  
Tannic Acid ◽  
Bacillus Megaterium ◽  
Catalytic Efficiency ◽  
Salmonella Typhi ◽  
Aspergillus Versicolor ◽  
Debranching Enzymes ◽  
Different Types ◽  
Microbial Strains ◽  
Hydrolysis Of

Advancement in green chemistry has increased the use of microbial hydrolyases in various industries and chemical processes because of high catalytic efficiency, specificity, cost-effectiveness and eco-friendly nature. Bioconversion of tannins such as tannic acid is achieved by tannin acyl hydrolase, also known as tannase. It converts tannic acid into glucose and gallic acid by catalyzing the hydrolysis of ester and depside linkages in tannic acid. Tyrosinase is monophenol and O-diphenol oxidase a copper containing enzyme catalyzes the oxidation of tyrosine and generates different types of pigment such as melanin. Xylanases hydrolyze xylan into its constituent sugar with the help of several debranching enzymes. Microbial strains isolated from various sources were screened for these hydrolyases: Bhavnagar marine salterns (Bacillus megaterium BVUC_01 and Bacillus licheniformis BVUCh_02); Okhamadhi marine salterns Aspergillus versicolor; Spoiled/infected pomegranate (Xenoacremonium falcatum, two strains PGF1 and PGF4, Bacillus velezensisPGF2 and Candida freyschussiiPGF3. The other laboratory maintained bacterial cultures namely, Bacillus subtilis, Pseudomonas aeruginosa, Staphylococcus aureus, Salmonella typhi were also used in this study. Asp. versicolor and Xen. falcatum (PGF1) produced all the three enzymes (tannase, tyrosinase and xylanase). B. licheniformis, B. megaterium, B. subtilis, B. velezensis produced tyrosinase and xylanase. Xen. falcatum (PGF4) and PGF2 produced tannase and xylanase. PGF3 produced tannase and tyrosinase. While, Bacillus megaterium and Salmonella typhi showed only tyrosinase activity. Candida freyschussii showed tannase activity. Staphylococcus aureus did not produce any of these enzymes.

scholarly journals Biochemical and Structural Characterization of a Novel Bacterial Tannase From Lachnospiraceae bacterium in Ruminant Gastrointestinal Tract

2021 ◽  
Vol 9 ◽  
Author(s):  
Lijun Guan ◽  
Kunlun Wang ◽  
Yang Gao ◽  
Jialei Li ◽  
Song Yan ◽  
...  
Keyword(s):  
Tannic Acid ◽  
Md Simulation ◽  
Catalytic Efficiency ◽  
Maximal Activity ◽  
Relative Activity ◽  
Hydrolyzable Tannins ◽  
Industrial Use ◽  
Hydrolysis Of ◽  
Lauryl Gallate

Tannases are a family of esterases that catalyze the hydrolysis of ester and depside bonds present in hydrolyzable tannins to release gallic acid. Here, a novel tannase from Lachnospiraceae bacterium (TanALb) was characterized. The recombinant TanALb exhibited maximal activity at pH 7.0 and 50°C, and it maintained more than 70% relative activity from 30°C to 55°C. The activity of TanALb was enhanced by Mg2+ and Ca2+, and was dramatically reduced by Cu2+ and Mn2+. TanALb is capable of degrading esters of phenolic acids with long-chain alcohols, such as lauryl gallate as well as tannic acid. The Km value and catalytic efficiency (kcat /Km) of TanALb toward five substrates showed that tannic acid (TA) was the favorite substrate. Homology modeling and structural analysis indicated that TanALb contains an insertion loop (residues 341–450). Based on the moleculer docking and molecular dynamics (MD) simulation, this loop was observed as a flap-like lid to interact with bulk substrates such as tannic acid. TanALb is a novel bacterial tannase, and the characteristics of this enzyme make it potentially interesting for industrial use.

The In vitro Evaluation of the Antimicrobial Activity of Quercus robur L. Methanolic and Aqueous Leaves’ Extracts, from the Algerian High Plateaus Against some Uropathogenic Microbial Strains

2019 ◽  
Vol 18 (5) ◽  
pp. 262-274
Author(s):  
E. Benyagoub ◽  
N. Nabbou ◽  
S. Boukhalkhel ◽  
I. Dehini
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Candida Albicans ◽  
Enterococcus Faecalis ◽  
Fusidic Acid ◽  
Quercus Robur ◽  
Diffusion Method ◽  
Phytochemical Analysis ◽  
Microbial Strains

The medicinal value of the plants is due to their chemical components that bring a definite physiological action on the human body to prevent the diseases. In this work, we investigated the antimicrobial activity of leaves’ extracts of Quercus robur L., collected from the Algerian upper highlands, on ten bacterial strains and one fungal strain known to be pathogenic. First, we performed a qualitative phytochemical analysis, and second, antimicrobial activity tests performed by agar diffusion method (disc and well) with the determination of MIC by broth macro-dilution method. Given the results, it appears that obtained macerates of Quercus robur L. were rich in bioactive phytoconstituents such as alkaloids, anthraquinones, saponins, tannins, and other components. The yield of aqueous and methanolic macerates of leaves was 8.5 ± 1.41 and 22.4 ± 4.36%, respectively. The bacterial resistance was relatively important to several antibiotics, namely, ampicillin, amoxicillin + clavulanic acid for strains of Escherichia coli and Salmonella sp. However, Staphylococcus aureus strains were resistant to fusidic acid, penicillin, and oxacillin; while Enterococcus faecalis was resistant to fusidic acid, penicillin, oxacillin, and ticarcillin. The antibacterial activity of the macerates toward tested microbial strains showed that the aqueous and methanolic macerates of the leaves were proportional to the tested concentration and active not only against Gram-positive and Gram-negative bacteria but also on the fungal species Candida albicans. The estimated MIC for Escherichia coli, Enterococcus faecalis, and Staphylococcus aureus was in the order of 10 mg/mL, which seems more effective than toward Salmonella sp., Klebsiella pneumoniae, Pseudomonas aeruginosa, and Candida albicans which were in the order of 30 mg/mL. These preliminary results confirm that the part of the studied plant had a very good antimicrobial activity that was proportional to the serial concentrations of the tested extracts.

Incidence of Staphylococcus aureus and its Enterotoxins in Chicken Meat and its Products

2020 ◽  
Keyword(s):  
Public Health ◽  
Staphylococcus Aureus ◽  
Health Hazard ◽  
Chicken Meat ◽  
Isolation Technique ◽  
Mean Values ◽  
Unsaturated Fat ◽  
Permissible Limits ◽  
Production Activity ◽  
Different Types

Chicken meat are being widely consumed as they contain high protein and a healthier unsaturated fat type. Chicken burger represent a consumer palatable chicken product. Both chicken and its products are liable to different types of contamination during their preparation and processing. Contamination by S. aureus and its enterotoxins poses a major public health hazard to chicken meat consumes. During this study 100 different samples of chicken fillet, deboned thigh, wing, mechanically deboned meat (MDM) and chicken burger (20 each) was collected from market and investigated for their S. aureus count and ability of the isolated strains to produce enterotoxins using conventional plating and isolation technique as well as using SET-RPLA toxin detection kit. Results revealed that mean values of S. aureus count in all samples exceeded the permissible limits and hence being unacceptable. MDM isolated exhibited staphylococcal enterotoxins (SEs) production of three different types SEA, SEC and SED. Meanwhile chicken burger S. aureus isolates produced only SEA and SEC enterotoxins. While isolated S. aureus from chicken fillet and deboned thigh didn’t exhibit any enterotoxin production activity. It’s recommended to follow the hygienic practices during different processing stages to avoid the risk of S. aureus and its enterotoxins.

scholarly journals Genetic Characterization of Methicillin Resistant and Sensitive, Vancomycin Intermediate Staphylococcus aureus Strains Isolated from Different Iranian Hospitals

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Seyed Asghar Havaei ◽  
Amir Azimian ◽  
Hosein Fazeli ◽  
Mahmood Naderi ◽  
Kiarash Ghazvini ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Genetic Analysis ◽  
Clinical Samples ◽  
Different Types ◽  
Health Care Policies ◽  
Global Health Care ◽  
Vancomycin Resistant ◽  
Epidemiological Evaluation ◽  
Mrsa Strains

Background. Global concerns have been raised due to upward trend of Vancomycin Intermediate Staphylococcus aureus (VISA) and Vancomycin Resistant Staphylococcus aureus (VRSA) reports which mean casting doubt on the absolute effectiveness of the last line of antibiotic treatment for S. aureus, vancomycin. Hence, epidemiological evaluation can improve global health care policies. Methodology. 171 Isolates of Staphylococcus aureus were collected from different types of clinical samples in selected hospitals in Isfahan, Mashhad, and Tehran, Iran. Then, they were evaluated by agar screening, disk diffusion, and MIC method to determine their resistance to vancomycin and methicillin. The isolated VISA strains were then confirmed with genetic analysis by the evaluation of mecA and vanA genes, SCCmec, agr, and spa type, and also toxin profiles. MLST was also performed. Results and Conclusion. Our data indicated that 67% of isolated S. aureus strains were resistant to methicillin. Furthermore, five isolates (2.9%) had intermediate resistance to vancomycin (VISA). In contrast to usual association of VISA with MRSA strains, we found two isolates of MSSA-VISA. Therefore, our data suggests a probable parallel growing trend of VISA towards MSSA, along with MRSA strains. However, more samples are required to confirm these primarily data. Moreover, genetic analysis of the isolated VISA strains revealed that these strains are endemic Asian clones.

Hidrolisis minyak biji asam jawa (tamarindus indica linn) menjadi asam lemaknya dan uji aktivitas antibakteri

2021 ◽  
Vol 2 (2) ◽  
pp. 100-104
Author(s):  
Arnanda Dhafin Rizky ◽  
Sutrisno Sutrisno ◽  
Parlan Parlan
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Fatty Acid ◽  
Potassium Hydroxide ◽  
Seed Oil ◽  
Acid Number ◽  
Moderate Intensity ◽  
Tamarindus Indica ◽  
Tamarind Seed ◽  
Hydrolysis Of

Saponification tamarind seed oil used potassium hydroxide and acidification with hydrochloric acid is produced fatty acid in the form of soft white solid, has melting point 50-55 degrees celcius. The result of this hydrolysis positive test of unsaturation. It has an acid number of 115.36, saponification number of 114.80, and iodine number of 53.34. The success of hydrolysis of oil into fatty acid is characterized by identification of IR spectra showing O-H vibration with moderate intensity and widening, C=O vibration of carboxylic acid with strong intensity. Fatty acids of tamarind seed have the potential as antibacterial to test bacteria Staphylococcus aureus and Escherichia coli with diameter respectively 7.31 mm and 7.58 mm. Minyak biji asam jawa yang disaponifikasi menggunakan kalium hidroksida dan pengasaman dengan asam klorida dihasilkan asam lemak berupa padatan lunak berwana putih, memiliki titik lebur 50-55 derajat celcius. hasil hidrolisis ini positif uji ketidakjenuhan, bilangan asam 115,36, bilangan penyabunan 114,80, dan bilangan iod 53,34. Keberhasilan hidrolisis minyak menjadi asam lemak ditandai dari identifikasi spektrum IR yang menunjukkan vibrasi ulur O-H dengan intensitas sedang dan melebar serta vibrasi ulur C=O asam karboksilat dengan intensitas kuat. Asam lemak biji asam jawa berpotensi sebagai antibakteri terhadap bakteri uji Staphylococcus aureus dan Escherichia coli dengan zona hambat masing-masing 7,31 mm dan 7,58 mm.

scholarly journals Identification and antibiogram study of bacterial species isolated from milk samples of different locations in Bangladesh

2016 ◽  
Vol 1 (3) ◽  
pp. 457-462 ◽  
Author(s):  
Md Nuruzzaman Munsi ◽  
Nathu Ram Sarker ◽  
Razia Khatun ◽  
Mohammed Khorshed Alam
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pathogenic Bacteria ◽  
Bacterial Species ◽  
Salmonella Typhi ◽  
Diffusion Method ◽  
Biochemical Tests ◽  
Public Health Importance ◽  
Milk Samples ◽  
First Choice

Cow’s milk containing pathogenic bacteria is an important threat to the consumers. The objectives of the present study were to identify the bacterial agents of public health importance in milk samples (n=35) of different locations and to determine their sensitivity to different antibiotics. The milk samples were collected and transported aseptically and subsequently allowed for culture in bacteriological media, Gram’s staining and biochemical tests for the identification of bacterial species. The bacteria identified were Staphylococcus aureus, Escherichia coli and Salmonella typhi, and their prevalence, in case of vendor milk specimens (n=28), were 96.43%, 53.57% and 35.71% respectively, and of brand milk specimens (n=7), were 42.86 %, 28.57% and 0%, respectively. This suggests that cautionary measures should be taken for quality milk production and consumption. The antibiotic sensitivity test was done by disc diffusion method and the average inhibition zones, in case of Staphylococcus aureus, were 32 mm for oxytetracycline, 26 mm for amoxicillin, 35 mm for ciprofloxacin, 27 mm for cefotaxime, 30 mm for ceftriaxone, 30 mm for azithromycin, and 26 mm for erythromycin; in case of Escherichia coli, were 5 mm for oxytetracycline, 9 mm for amoxicillin, 22 mm for ciprofloxacin, 30 mm for cefotaxime, 31 mm for ceftriaxone, 15 mm for azithromycin, and 0 mm for erythromycin; in case of Salmonella typhi., were 25 mm for oxytetracycline, 24 mm for amoxicillin, 38 mm for ciprofloxacin, 31 mm for cefotaxime, 34 mm for ceftriaxone, 24 mm for azithromycin, and 0 mm for erythromycin. Therefore, ciprofloxacin and ceftriaxone may be the antibiotics of first choice, and cefotaxime and azithromycin may be the second choice among the test antibiotics for the treatment of illness caused by these bacteria.Asian J. Med. Biol. Res. December 2015, 1(3): 457-462

scholarly journals Cover Feature: Distance between Metal Centres Affects Catalytic Efficiency of Dinuclear CoIII Complexes in the Hydrolysis of a Phosphate Diester (Eur. J. Org. Chem. 39/2018)

2018 ◽  
Vol 2018 (39) ◽  
pp. 5335-5335
Author(s):  
Eva Szusanna Bencze ◽  
Cristiano Zonta ◽  
Fabrizio Mancin ◽  
Leonard J. Prins ◽  
Paolo Scrimin
Keyword(s):  
Catalytic Efficiency ◽  
Phosphate Diester ◽  
Hydrolysis Of

scholarly journals Preliminary phytochemical screening and susceptibility of bacteria pathogens to whole extract of evolvulus alsinoides (L.)

1970 ◽  
Vol 18 ◽  
pp. 16-20
Author(s):  
BA Omogbai ◽  
FA Eze
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Bacillus Cereus ◽  
Pathogenic Bacteria ◽  
Volatile Oil ◽  
Salmonella Typhi ◽  
Phytochemical Screening ◽  
Evolvulus Alsinoides ◽  
And Staphylococcus Aureus

Context: Plant based antimicrobial represent a vast untapped source for medicines and further exploration of plant antimicrobial neeto occur. Evolvulus alsinoides (L) (Convolvulaceae) is a perennial herb is used in traditional medicine in East Asia, India, Africa and Philippines to cure fever, cough, cold, venereal diseases, azoospermia, adenitis and dementia.   Objective: The objective of this research was to evaluate the antimicrobial activity of the extracts of E. alsinoides on some clinical microbial isolates.   Materials and Methods: The ed thanolic and aqueous extracts of the whole plant (leaves and twigs) were analysed for alkanoids, tannins, glycosides, steroids, flavonoids, saponins, volatile oil and resins. The determination of antibacterial activity was done using the agar well diffusion technique. Pure cultures of pathogenic bacteria such as Bacillus cereus, Staphylococcus aureus, Micrococcus leutus, Klebsiella Pneumoniae, Pseudomonas aeruginosa, Escherichia coli and Salmonella typhi were used for antibacterial activity assay, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC).   Results: The ethanolic extract of the plant had MIC values ranging from 16 mg/ml to 512.5 mg/ml. The least MIC was 16mg-ml against Salmonella typhi while Bacillus cereus and Staphylococcus aureus showed the highest MIC of 512.5 mg-ml. In the aqueous extract the MIC ranged between 512.5 to >1025 mg/ml. Salmonella typhi, Micrococcus luteus and Staphylococcus aureus were not inhibited by the water extract. Phytochemical result showed ethanol to be a better solvent for the extraction of the bioactive agents in this plant which include: glycosides, alkaloids, saponins, tannins, flavonoids and volatile oil.   Conclusion: In this study the gram-negative organisms had the lowest MICs and MBCs. This suggests their higher susceptibility to the extract of this plant. On the basis of the result obtained in this investigation it can be concluded that ethanol extract of Evolvulus alsinoides had significant in vitro broad spectrum antimicrobial activity.   Keywords: Evolvulus alsinoides; Phytochemical screening; Antibacterial activity. DOI: http://dx.doi.org/10.3329/jbs.v18i0.8769 JBS 2010; 18(0): 16-20

scholarly journals Enzyme-catalyzed reactions in different types of high-pressure enzymatic reactors

2006 ◽  
Vol 12 (3) ◽  
pp. 159-163
Author(s):  
Mateja Primozic ◽  
Maja Habulin ◽  
Muzafera Paljevac ◽  
Zeljko Knez
Keyword(s):  
High Pressure ◽  
Atmospheric Pressure ◽  
Ceramic Membranes ◽  
Stirred Tank ◽  
Optimal Temperature ◽  
Stirred Tank Reactor ◽  
Tank Reactor ◽  
Humicola Insolens ◽  
Different Types ◽  
Hydrolysis Of

The enzyme-catalyzed hydrolysis of carboxy-methyl cellulose (CMC) was performed in three different types of reactors; in a batch stirred-tank reactor (BSTR) operating at atmospheric pressure, in a high-pressure batch stirred-tank reactor (HP BSTR) and in a high-pressure continuous tubular-membrane reactor (HP CTMR). In the high-pressure reactors aqueous SC CO2 was used as the reaction medium. The aim of our research was optimization of the reaction parameters for reaction performance. All the reactions were catalyzed by cellulase from Humicola insolens. Glucose production in the high-pressure batch stirred-tank reactor was faster than in the BSTR at atmospheric pressure. The optimal temperature for the reaction performed in the BSTR at atmospheric pressure was 30?C, while the optimal temperature for the reaction performed in SC CO2 was 32?C. The influence of the application of tubular ceramic membranes in the high-pressure reaction system was studied on the model reaction of CMC hydrolysis at atmospheric pressure and in SC CO2. The reaction was catalyzed by cellulase from Humicola insolens covalently linked to the surface of the ceramic membrane. The hydrolysis of CMC in SC CO2 and at atmospheric pressure was performed for a long time period. The reaction carried out in SC CO2 was more productive than the reaction performed at atmospheric pressure.

scholarly journals Combination of Autohydrolysis and Catalytic Hydrolysis of Biomass for the Production of Hemicellulose Oligosaccharides and Sugars

Reactions ◽  
2021 ◽  
Vol 3 (1) ◽  
pp. 30-46
Author(s):  
Léa Vilcocq ◽  
Agnès Crepet ◽  
Patrick Jame ◽  
Florbela Carvalheiro ◽  
Luis C. Duarte
Keyword(s):  
Agricultural Waste ◽  
Solid Acid Catalyst ◽  
Acid Catalyst ◽  
Energy Crop ◽  
Catalytic Hydrolysis ◽  
Experimental Conditions ◽  
Different Types ◽  
Hemicellulosic Sugars ◽  
Hydrolysis Of

Three different types of biomass sourced from forestry waste (eucalyptus residues), agricultural waste (wheat straw), and energy crop (miscanthus) were used as starting materials to produce hemicellulosic sugars, furans (furfural and hydroxymethylfurfural), and oligosaccharides. A two-step hybrid process was implemented; biomass was first autohydrolysed without any additive to extract hemicelluloses and dissolve it in water. Then, the hydrolysate was treated with a solid acid catalyst, TiO2-WOx, in order to achieve hydrolysis and produce monomeric sugars and furans. This article investigates the role of the biomass type, autohydrolysis experimental conditions, polymerisation degree and composition of hemicelluloses on the performance of the process coupling autohydrolysis and catalytic hydrolysis. The highest global yields of both oligosaccharides and monomeric sugars were obtained from Eucalyptus (37% and 18%, respectively).

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