scholarly journals Microbial Isobutyronitrile Utilization under Haloalkaline Conditions

2007 ◽  
Vol 73 (17) ◽  
pp. 5574-5579 ◽  
Author(s):  
Dimitry Y. Sorokin ◽  
Sander van Pelt ◽  
Tatjana P. Tourova ◽  
Gerard Muyzer
Keyword(s):  
Carboxylic Acids ◽  
Nitrile Hydratase ◽  
Bacterial Species ◽  
Intracellular Localization ◽  
Soda Lake ◽  
Bacterial Strains ◽  
Ph Optimum ◽  
Hydrolysis Products ◽  
Aliphatic Nitriles ◽  
Hydrolysis Of

ABSTRACT The utilization of isobutyronitrile (iBN) as a C and N source under haloalkaline conditions by microbial communities from soda lake sediments and soda soils was studied. In both cases, a consortium consisting of two different bacterial species capable of the complete degradation and utilization of iBN at pH 10 was selected. The soda lake sediment consortium consisted of a new actinobacterium and a gammaproteobacterium from the genus Marinospirillum. The former was capable of fast hydrolysis of aliphatic nitriles to the corresponding amides and much-slower further hydrolysis of the amides to carboxylic acids. Its partner cannot hydrolyze nitriles but grew rapidly on amides and carboxylic acids, thus acting as a scavenger of products released by the actinobacterium. The soda soil consortium consisted of two Bacillus species (RNA group 1). One of them initiated nitrile hydrolysis, and the other utilized the hydrolysis products isobutyroamide (iBA) and isobutyrate (iB). In contrast to the actinobacterium, the nitrile-hydrolyzing soil Bacillus grew rapidly with hydrolysis products, but it was dependent on vitamins most probably supplied by its product-utilizing partner. All four bacterial strains isolated were moderately salt-tolerant alkaliphiles with a pH range for growth from pH 7.0 to 8.5 up to 10.3 to 10.5. However, both their nitrile hydratase and amidase activities had a near-neutral pH optimum, indicating an intracellular localization of these enzymes. Despite this fact, the study demonstrated a possibility of whole-cell biocatalytic hydrolysis of various nitriles at haloalkaline conditions.

scholarly journals Purification and characterization of an extracellular (1 → 6)-β-glucanase from the filamentous fungus Acremonium persicinum

1996 ◽  
Vol 316 (3) ◽  
pp. 841-846 ◽  
Author(s):  
Stuart M. PITSON ◽  
Robert J. SEVIOUR ◽  
Barbara M. McDOUGALL ◽  
Bruce A. STONE ◽  
Maruse SADEK
Keyword(s):  
Molecular Mass ◽  
Filamentous Fungus ◽  
Gel Filtration ◽  
Purification And Characterization ◽  
Eisenia Bicyclis ◽  
Ph Optimum ◽  
Hydrolysis Products ◽  
Sds Page ◽  
Hydrolysis Of

An endo-(1 → 6)-β-glucanase has been isolated from the culture filtrates of the filamentous fungus Acremonium persicinum and purified by (NH4)2SO4 precipitation followed by anion-exchange and gel-filtration chromatography. SDS/PAGE of the purified enzyme gave a single band with an apparent molecular mass of 42.7 kDa. The enzyme is a non-glycosylated, monomeric protein with a pI of 4.9 and pH optimum of 5.0. It hydrolysed (1 → 6)-β-glucans (pustulan and lutean), initially yielding a series of (1 → 6)-β-linked oligoglucosides, consistent with endo-hydrolytic action. Final hydrolysis products from these substrates were gentiobiose and gentiotriose, with all products released as β-anomers, indicating that the enzyme acts with retention of configuration. The purified enzyme also hydrolysed Eisenia bicyclis laminarin, liberating glucose, gentiobiose, and a range of larger oligoglucosides, through the apparent hydrolysis of (1 → 6)-β- and some (1 → 3)-β-linkages in this substrate. Km values for pustulan, lutean and laminarin were 1.28, 1.38, and 1.67 mg/ml respectively. The enzyme was inhibited by N-acetylimidazole, N-bromosuccinimide, dicyclohexylcarbodi-imide, Woodward's Regent K, 2-hydroxy-5-nitrobenzyl bromide, KMnO4 and some metal ions, whereas D-glucono-1,5-lactone and EDTA had no effect.

Nocardia globerula NHB-2: a versatile nitrile-degrading organism

2005 ◽  
Vol 51 (8) ◽  
pp. 705-708 ◽  
Author(s):  
Tek Chand Bhalla ◽  
Harish Kumar
Keyword(s):  
Nitrile Hydratase ◽  
Enrichment Culture ◽  
Nutrient Broth ◽  
Amidase Activity ◽  
Degrading Bacterium ◽  
Nitrilase Activity ◽  
Aliphatic Nitrile ◽  
Aromatic Amide ◽  
Aliphatic Nitriles ◽  
Hydrolysis Of

A versatile nitrile-degrading bacterium was isolated by enrichment culture from the soil of a forest near Manali, Himachal Pradesh, India, and was identified as Nocardia globerula. This organism contains 3 enzymes with nitrile-degrading activity: nitrilase, nitrile hydratase, and amidase. Nocardia globerula NHB-2 cells grown on nutrient broth supplemented with 1% glucose and 0.1% yeast extract exhibited nitrile hydratase–amidase activity specific for saturated aliphatic nitriles or amide, while addition of acetonitrile in nutrient broth yielded cells with nitrile hydratase–amidase that in addition to saturated aliphatic nitriles–amide also hydrolyzed aromatic amide. Nocardia globerula NHB-2 cultivated on nutrient broth containing propionitrile exhibited nitrilase activity that hydrolyzed aromatic nitrile and unsaturated aliphatic nitrile. The versatility of this organism in the hydrolysis of various nitriles and amides makes it a potential bioresource for use in organic synthesis.Key words: Nocardia globerula NHB-2, nitrilase, nitrile hydratase, amidase, nitrile–amide degradation.

scholarly journals Amylase-Producing Fungi and Bacteria Associated with Some Food Processing Wastes

2021 ◽  
Vol 38 (1) ◽  
pp. 74-82
Author(s):  
T. Okunwaye ◽  
P.O. Uadia ◽  
B.O. Okogbenin ◽  
E.A. Okogbenin ◽  
D.C. Onyia ◽  
...  
Keyword(s):  
Amylase Activity ◽  
Bacterial Species ◽  
Bacterial Count ◽  
Industrial Wastes ◽  
Bacterial Strains ◽  
Glycosidic Bonds ◽  
Processing Wastes ◽  
Food Processing Wastes ◽  
Hydrolysis Of ◽  
Coconut Meat

Amylases are enzymes that catalyze the hydrolysis of glycosidic bonds present in starch to release simple sugars. They are one of the most important enzymes in numerous commercial processes. In this investigation, fungal and bacterial strains from the following agro-industrial wastes were isolated and screened for amylolytic ability: soil from oil palm plantation, shea seed, date fruit, coconut meat, cassava effluent, cassava peel, cassava tubers, yam and potato tubers, starch medium, parboiled water from noodles and rice. The results revealed the presence of Geotrichum, Aspergillus, Penicillium, Trichoderma, Rhizopus and Fusarium spp. Five major genera of bacterial species namely Corynebacterium, Pseudomonas, Lactobacillus, Micrococcus and Bacillus were isolated and screened for amylase activity. Cassava soil had the highest heterotrophic bacterial count of 5.7 x105cfu/g and coconut meat waste had the lowest heterotrophic bacterial count of 1.3 x105cfu/g. All isolated microorganisms had the amylolytic ability. The fungal isolates had higher amylase activity when compared with the bacterial isolates. This investigation reveals organisms with high amylase activity.

Stimulation of α-glucosidases from fast-growing rhizobia and Agrobacterium tumefaciens by K+, NH+4, and Rb+

1990 ◽  
Vol 36 (3) ◽  
pp. 223-227 ◽  
Author(s):  
Inger Hoelzle ◽  
John G. Streeter
Keyword(s):  
Agrobacterium Tumefaciens ◽  
Rhizobium Leguminosarum ◽  
Bacterial Species ◽  
Ion Concentration ◽  
Substrate Affinity ◽  
Experimental Conditions ◽  
Ph Optimum ◽  
Fast Growing ◽  
Fast Growing Rhizobia ◽  
Hydrolysis Of

Extracts from cultured fast-growing rhizobia and Agrobacterium tumefaciens contain enzymes for hydrolysis of the α-glucosides maltose, sucrose, and α,α-trehalose. The hydrolysis of all three sugars was stimulated by the presence of K+, Rb+, or [Formula: see text]. This stimulation varied from less than 2-fold to more than 12-fold, depending on the bacterial species, culture conditions, and experimental conditions, such as type of enzyme, buffer, and ion concentration. Eight other ions tested, including several divalent cations, did not have any stimulatory effect. Other sources of enzyme (Escherichia coli, Saccharomyces cerevisiae, Oryza sativa, porcine kidney, and Medicago sativa and Glycine max nodule cytosol) contained α-glucosidases that differed in both substrate specificity and pH optima and were not affected by K+, Rb+ or [Formula: see text] ions. Bacteroids from G. max and Phaseolus vulgaris nodules did not have detectable α-glucosidase activity. Growth of Rhizobium leguminosarum biovar phaseoli USDA 2667 with one of the α-glucosides as carbon source increased Vm and substrate affinity for all three disaccharidase activities. The pH optimum for all three enzyme activities in R. leguminosarum bv. phaseoli USDA 2667 was 6.6. Stimulation by specific monovalent cations appears to be a novel property of α-glucosidases in the bacterial family Rhizobiaceae. Key words: maltose, sucrose, trehalose, disaccharidases, Rhizobiaceae.

scholarly journals THE HISTOCHEMICAL DEMONSTRATION OF GLYCERALDEHYDE-3-PHOSPHATE DEHYDROGENASE ACTIVITY

1961 ◽  
Vol 9 (3) ◽  
pp. 573-581 ◽  
Author(s):  
S. Ralph Himmelhoch ◽  
Morris J. Karnovsky
Keyword(s):  
Dehydrogenase Activity ◽  
Intracellular Localization ◽  
Histochemical Demonstration ◽  
Cellular Level ◽  
Tissue Component ◽  
Ph Optimum ◽  
Coenzyme Specificity ◽  
Acid Acid ◽  
Activating Agent ◽  
Hydrolysis Of

A histochemical method for demonstration of glyceraldehyde-3-phosphate dehydrogenation by tissues is described. The method utilizes Nitro BT as an indicator, glyceraldehyde-3-phosphate obtained from hydrolysis of commercially obtainable glyceraldehyde-3-phosphate diethylacetal (monobarium salt) as substrate, and (ethylenediamine)tetraacetic acid acid disodium as an activating agent in a medium buffered to pH 7.2 by 0.2 M sodium phosphate. The heat lability, substrate and coenzyme specificity, and sulfhydryl and phosphate dependence of the tissue component catalyzing this reaction indicate that glyceraldehyde-3-phosphate dehydrogenase activity is being demonstrated. The disparity between the known pH optimum of this enzyme and that determined histochemically, and the anomalous histochemical localization to mitochondria of this enzyme which has been found in the soluble fraction by differential centrifugation, are thought to result from the diaphorase dependence of the tetrazolium methods and to emphasize the need for caution in the interpretation of histochemically determined intracellular localization of dehydrogenating enzymes. The evidence gathered by previous workers concerning the feasibility of demonstrating specific dehydrogenases with Nitro BT, and the correspondence of the distribution of glyceraldehyde-3-phosphate dehydrogenase determined histochemically with available quantitative data, suggest that at the cellular level the histochemical results accurately reflect the distribution of this enzyme.

Total Synthesis and Antibacterial Screening of (±)-6,8-Dihydroxy-3- undecyl-3,4-dihydroisochromen-1-one: A Structural Analogue of Metabolites from Ononis natrix

2019 ◽  
Vol 16 (3) ◽  
pp. 245-248
Author(s):  
Hummera Rafique ◽  
Aamer Saeed ◽  
Ehsan Ullah Mughal ◽  
Muhammad Naveed Zafar ◽  
Amara Mumtaz ◽  
...  
Keyword(s):  
Total Synthesis ◽  
Structural Analog ◽  
Diffusion Method ◽  
Bacterial Strains ◽  
Antibacterial Screening ◽  
Maximum Inhibition ◽  
Bacillus Subtilus ◽  
Hydrolysis Of ◽  
Direct Condensation

Background: (±)-6,8-Dihydroxy-3-undecyl-3,4-dihydroisochromen-1-one is one of the structural analog of several substituted undecylisocoumarins isolated from Ononis natrix (Fabaceae), has been successfully synthesized by direct condensation of homopthalic acid (1) with undecanoyl chloride yields isochromen-1-one (2). Methods: Alkaline hydrolysis of (2) gave the corresponding keto-acid (3), which is then reduced to hydroxy acid (4) then its cyclodehydration was carried out with acetic anhydride to afford 3,4- dihydroisochromen-1-one (5). Followed by demethylation step, the synthesis of target 6,8- dihydroxy-7-methyl-3-undecyl-3,4-dihydroisocoumarin (6) was achieved. Results: In vitro antibacterial screening of all the synthesized compounds were carried out against ten bacterial strains by agar well diffusion method. Conclusion: Newly synthesized molecules exhibited moderate antibacterial activity and maximum inhibition was observed against Bacillus subtilus and Salmonella paratyphi.

Polarographic study of hydrolysis of [8-lysine]vasopressin and its derivatives with blood serum of pregnant women

1980 ◽  
Vol 45 (4) ◽  
pp. 1099-1108 ◽  
Author(s):  
Mikuláš Chavko ◽  
Michal Bartík ◽  
Evžen Kasafírek
Keyword(s):  
Blood Serum ◽  
Pregnant Women ◽  
Degree Of Hydrolysis ◽  
Polarographic Study ◽  
Ph Optimum ◽  
Lysine Vasopressin ◽  
Rate Of Hydrolysis ◽  
Hydrolysis Of ◽  
Vasopressin Analogues

A polarographic study of the hydrolysis of [8-lysine]vasopressin and some hormonogens of the vasopressin series with the blood serum of women in the last week of pregnancy was studied. The dependence of hydrolysis on pH (pH optimum: 7.4-7.50, substrate concentration (Km 1.2 . 10-5M), pH stability and thermal stability were determined. The rate of hydrolysis of individual vasopressin analogues decreases in the order: [8-lysine]vasopressin > Nα-glycyl-prolyl[8-lysine]-vasopressin > Nα-leucyl-[8-lysine]vasopressin > Nα-alanyl-[8-lysine]vasopressin > Nα-phenyl alanyl-[8-lysine]vasopressin > Nα-diglycyl-[8-lysine]vasopressin > Nα-prolyl-[8-lysine]vasopressin > Nα-triglycyl-[8-lysine]vasopressin > Nα-sarcosyl-glycyl-[8-lysine]vasopressin. The degree of hydrolysis gradually increases to a multiple with the length of the pregnancy in consequence of the presence of oxytocine. However, vasopressin is also hydrolysed to a small extent with the enzymes from the blood sera of non-pregnant women. Under similar analytical conditions oxytocin was not hydrolysed with the sera of non-pregnant women and therefore oxytocin is a more suitable substrate than vasopressin for polarographic determination of serum oxytocinase.

scholarly journals The Conservation of Low Complexity Regions in Bacterial Proteins Depends on the Pathogenicity of the Strain and Subcellular Location of the Protein

Genes ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 451
Author(s):  
Pablo Mier ◽  
Miguel A. Andrade-Navarro
Keyword(s):  
Membrane Proteins ◽  
Outer Membrane ◽  
Bacterial Species ◽  
Outer Membrane Proteins ◽  
Subcellular Location ◽  
Low Complexity ◽  
Extracellular Proteins ◽  
Bacterial Strains ◽  
Bacterial Proteins ◽  
Protein Subcellular Location

Low complexity regions (LCRs) in proteins are characterized by amino acid frequencies that differ from the average. These regions evolve faster and tend to be less conserved between homologs than globular domains. They are not common in bacteria, as compared to their prevalence in eukaryotes. Studying their conservation could help provide hypotheses about their function. To obtain the appropriate evolutionary focus for this rapidly evolving feature, here we study the conservation of LCRs in bacterial strains and compare their high variability to the closeness of the strains. For this, we selected 20 taxonomically diverse bacterial species and obtained the completely sequenced proteomes of two strains per species. We calculated all orthologous pairs for each of the 20 strain pairs. Per orthologous pair, we computed the conservation of two types of LCRs: compositionally biased regions (CBRs) and homorepeats (polyX). Our results show that, in bacteria, Q-rich CBRs are the most conserved, while A-rich CBRs and polyA are the most variable. LCRs have generally higher conservation when comparing pathogenic strains. However, this result depends on protein subcellular location: LCRs accumulate in extracellular and outer membrane proteins, with conservation increased in the extracellular proteins of pathogens, and decreased for polyX in the outer membrane proteins of pathogens. We conclude that these dependencies support the functional importance of LCRs in host–pathogen interactions.

scholarly journals Isolation and efficacy of two bacterial strains antagonists of Erwinia amylovora and Pectobacterium carotovorum

2021 ◽  
Vol 31 (1) ◽  
Author(s):  
M’hamed BENADA ◽  
Boualem BOUMAAZA ◽  
Sofiane BOUDALIA ◽  
Omar KHALADI
Keyword(s):  
Fire Blight ◽  
Erwinia Amylovora ◽  
Bacterial Species ◽  
Crop Protection ◽  
Soft Rot ◽  
Causal Agent ◽  
Plant Diseases ◽  
Ecological Niches ◽  
Pectobacterium Carotovorum ◽  
Bacterial Strains

Abstract Background The development of ecofriendly tools against plant diseases is an important issue in crop protection. Screening and selection process of bacterial strains antagonists of 2 pathogenic bacterial species that limit very important crops, Erwinia amylovora, the causal agent of the fire blight disease, and Pectobacterium carotovorum, the causal agent of bacterial potato soft rot, were reported. Bacterial colonies were isolated from different ecological niches, where both pathogens were found: rhizosphere of potato tubers and fruits and leaves of pear trees from the northwest region of Algeria. Direct and indirect confrontation tests against strains of E. amylovora and P. carotovorum were performed. Results Results showed a significant antagonistic activity against both phytopathogenic species, using direct confrontation method and supernatants of cultures (p<0.005). In vitro assays showed growth inhibitions of both phytopathogenic species. Furthermore, results revealed that the strains of S. plymuthica had a better inhibitory effect than the strains of P. fluorescens against both pathogens. In vivo results on immature pear fruits showed a significant decrease in the progression of the fire blight symptoms, with a variation in the infection index from one antagonistic strain to another between 31.3 and 50%, and slice of potato showed total inhibition of the pathogen (P. carotovorum) by the antagonistic strains of Serratia plymuthica (p<0.005). Conclusion This study highlighted that the effective bacteria did not show any infection signs towards plant tissue, and considered as a potential strategy to limit the fire blight and soft rot diseases.

scholarly journals Novel Amino Acid Derivatives of Quinolines as Potential Antibacterial and Fluorophore Agents

2020 ◽  
Vol 88 (4) ◽  
pp. 57
Author(s):  
Oussama Moussaoui ◽  
Rajendra Bhadane ◽  
Riham Sghyar ◽  
El Mestafa El Hadrami ◽  
Soukaina El Amrani ◽  
...  
Keyword(s):  
Amino Acid ◽  
Methyl Esters ◽  
Amino Acid Derivatives ◽  
Bacterial Strains ◽  
Fluorescent Properties ◽  
Topoisomerase Iv ◽  
Microdilution Method ◽  
Hydrolysis Of ◽  
Derivatives Of

A new series of amino acid derivatives of quinolines was synthesized through the hydrolysis of amino acid methyl esters of quinoline carboxamides with alkali hydroxide. The compounds were purified on silica gel by column chromatography and further characterized by TLC, NMR and ESI-TOF mass spectrometry. All compounds were screened for in vitro antimicrobial activity against different bacterial strains using the microdilution method. Most of the synthesized amino acid-quinolines show more potent or equipotent inhibitory action against the tested bacteria than their correspond esters. In addition, many of them exhibit fluorescent properties and could possibly be utilized as fluorophores. Molecular docking and simulation studies of the compounds at putative bacterial target enzymes suggest that the antimicrobial potency of these synthesized analogues could be due to enzyme inhibition via their favorable binding at the fluoroquinolone binding site at the GyrA subunit of DNA gyrase and/or the ParC subunit of topoisomerase-IV.

Sign in / Sign up

Export Citation Format

Share Document