scholarly journals Potential of PHA Accumulation in Escherichia Coli, Bacillus Subtilis and Pseudomonas Aeruginosa Cultured on Agro-Industrial Byproducts

2020 ◽  
Vol 9 (7) ◽  
pp. 950-954
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Bacillus Subtilis ◽  
Wheat Bran ◽  
Cost Effective ◽  
Natural Polymers ◽  
Inoculum Concentration ◽  
Cane Molasses ◽  
E Coli ◽  
Dry Cell Weight

Polyhydroxyalkanoates (PHAs) are type of natural polymers which are synthesized by different microorganisms to increase their survival rate during environmental change or stress conditions. The biodegradable polymers are an alternative solution to non-renewable petroleum derived plastics. The aim of this study is to produce PHAs by Escherichia coli, Bacillus subtilis and Pseudomonas aeruginosa using agro and industrial waste such as wheat bran and cane molasses. In this work, the effect of different media on each bacterium was studied. The optimum environmental condition that supported the PHA production by the three strains was inoculum concentration of 8%, pH 7.0 and temperature of 30°C. The medium was fermented for five days in orbital shaker. Each day samples were collected and analyzed. Dry cell weight and PHA accumulated was observed for each of the bacteria. On the basis of data obtained in the present work, compared to B. subtilis and E. coli, P. aeruginosa was capable to accumulate 70.27% of PHA by using Cane molasses and Wheat bran as substrate. This could be employed for industrial application after subsequent optimization of the conditions of PHA synthesis. The present study explored the potential of Pseudomonas aeruginosa to produce cost-effective PHA as an alternative to petroleum based plastics

scholarly journals ВИЗНАЧЕННЯ АНТИМІКРОБНОЇ АКТИВНОСТІ БЕДРИНЦЮ ЛОМИКАМЕНЕВОГО ЕКСТРАКТУ ГУСТОГО

2019 ◽  
pp. 104-110
Author(s):  
E. A. Parashchuk ◽  
N. I. Tkachuk ◽  
S. M. Marchyshyn ◽  
H. R. Kozyr
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Bacillus Subtilis ◽  
Candida Albicans ◽  
E Coli

Мета роботи. Визначення антимікробної активності бедринцю ломикаменевого підземних органів екстракту густого. Матеріали і методи.  Oб’єктoм для дoслідження обрано бедринцю ломикаменевого підземних органів екстракт густий (БЕГ-1, одержаний екстрагуванням 75 % етанолом і БЕГ-2, екстрагент 85 % етанол). В якості тест-культур використовували 5 музейних штамів: грампозитивні мікроорганізми Staphylococcus aureus АТСС 6538, спорову культуру Bacillus subtilis АТСС 6633, грамнегативну культуру Escherichia coli АТСС 25922 та Pseudomonas aeruginosa АТСС 9027. Антифунгальну дію з’ясовували відносно Candida albicans АТСС 885-653. Бактеріостатичні властивoсті дoсліджуваних oб’єктів встанoвлювали за результатами росту еталонних штамів мікроорганізмів у нативному водному розчині бедринцю та в розведені 1:2 та 1:4 в м'ясо-пептонному бульйоні; бактерицидні – за відсутністю росту вмісту пробірок із розведенням екстракту на щільних пoживних середoвищах (м’ясо-пептонний агар – МПА) для грампозитивних мікроорганізмів S. aureus, B. subtilis, для грамнегативної культури E. coli, P. аeruginosa. Агар Сабуро використовували для дріжджеподібних грибів роду Candida (C. аlbicans). Результати й обговорення. Бедринцю ломикаменевого підземних органів екстракт густий має широкий спектр антибактеріальної активності. Нативний екстракт БЕГ-1 по відношенню до тест-штамів S. aureus, B. subtilis, C. аlbicans проявляв бактерицидну дію. Бактеріостатичну дію він проявляв до P. aeruginosa, а по відношенню до E. coli антимікробного ефекту не виявлено. Екстракти в розведені 1:2 та 1:4 проявили бактерицидну дію відносно B. subtilis, бактеріостатичну – до S. aureus, C. albicans і не виявлено протимікробної дії до E. coli та P. aeruginosa. Нативний зразок БЕГ-2 по відношенню до усіх досліджуваних 5 тест–штамів проявив бактерицидну активність; у розведені 1:2 та 1:4 проявляв бактерицидну та бактеріостатичну дію відносно S. aureus, B. subtilis, C. albicans. Антимікробна дія по відношенню до E. coli та P. aeruginosa не виявлена. Антимікрoбну активність нативного бедринцю ломикаменевого екстракту густого також вивчали у дoслідах in vitro методом дифузії в агар –  метод “колодязів”. Штами S. aureus, C. albicans, B. subtilis, P. aeruginosa, E. coli проявили чутливість до нативного бедринцю ломикаменевого підземних органів екстракту густого. Грампозитивні бактеріальні штами S. aureus,а також гриби C. albicans, B. subtilis є найбільш чутливими до  БЕГ-2, а БЕГ-1 проявляв порівняно меншу чутливість. Грамнегативні культури P. aeruginosa та E. coli також проявили помірну чутливість до  БЕГ-1, але значно більшу чутливість до БЕГ-2. Висновки. 1. Експериментально встановлено, що обидва досліджувані зразки бедринцю ломикаменевого підземних органів екстракту густого проявляють антибактеріальну активність. 2. Бедринцю ломикаменевого підземних органів екстракт густий проявляв більш виражену антимікробну активність по відношенню до грампозитивної мікрофлори, тому є перспективним для створення лікарського засобу з антимікробними властивостями.

scholarly journals Aktivitas Antimikroba Ekstrak Etanol dan Fraksi Organik Rimpang Wualae (Etlingera elatior (Jack) R.M. Smith)

2019 ◽  
Vol 5 (1) ◽  
Author(s):  
Wa Ode Sitti Musnina ◽  
W Wahyuni ◽  
Fadhliyah Malik ◽  
Yusni Oktaviani Timung ◽  
Carla Wulandari Sabandar
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Bacillus Subtilis ◽  
Candida Albicans ◽  
Streptococcus Mutans ◽  
E Coli ◽  
Plate Technique ◽  
Etlingera Elatior

Wualae (Etlingera elatior (Jack) R.M Smith) merupakan tanaman rempah yang digunakan oleh masyarakat sebagai obat tradisional. Penelitian ini bertujuan untuk mengetahui metabolit sekunder, aktivitas antibakteri dan aktivitas antijamur ekstrak etanol dan fraksi organik  rimpang wualae. Rimpang wualae diekstraksi dengan metode maserasi menggunakan etanol kemudian di fraksinansi menggunakan pelarut n-heksana, etil asetat, dan metanol. Fraksi n-heksana, etil asetat, dan metanol diuji secara in vitro dengan metode Cup-plate technique, yang dilakukan terhadap bakteri Gram positif Staphylococcus aureus ATCC 25923, Bacillus subtilis FNCC 0060 dan Streptococcus mutans ATCC 2517 dan bakteri Gram negatif Escherichia coli ATCC 35218, Pseudomonas aeruginosa, Salmonella enteric dan jamur Candida albicans ATCC 10231. Kandungan senyawa metabolit sekunder rimpang wualae ditentukan dengan metode skrining fitokima menggunakan perekasi warna. Hasil skrining fitokimia ekstrak etanol fraksi n-heksana, etil asetat, metanol dan etanol rimpang wualae memiliki kandungan alkaloid, flavonoid, saponin, tannin dan terpenoid. Ekstrak etanol mengandung alkaloid, flavonoid, saponin, tannin, dan terpenoid, fraksi n-heksana mengandung terpenoid, fraksi etil asetat mengandung flavonoid, tannin dan terpenoid, fraksi metanol mengandung alkaloid, saponin, tannin, fraksi etanol mengandung flavonoid, saponin, tannin, dan terpenoid.  Hasil pengujian aktivitas antibakteri menunjukkan bahwa ekstrak etanol, fraksi n-heksana, etil asetat, metanol dan etanol rimpang wualae tidak aktif terhadap bakteri S. aureus, B. subtilis, S. mutans, E. coli, P, aeruginosa dan S. enterica pada konsentrasi 100-12,5 mg/mL. Pengujian antijamur menunjukkan bahwa fraksi etil asetat aktif terhadap jamur C. albicans  pada konsentrasi 100, 50, 25, dan 12,5 mg/mL dengan nilai DDH masing-masing sebesar nilai 9,75; 9,5; 8,75; dan 8 mmKata kunci: wualae, Etlingera, antimikroba, obat tradisional, Sulawesi TenggaraJurusan Farmasi Fakultas Matematika dan Ilmu Pengetahuan Alam, Universitas Tadulako, Jl. Soekarno Hatta Km. 9 Palu

Antagonistic activity of Bacillus subtilis strains isolated from various sources

2018 ◽  
Vol 8 (2) ◽  
pp. 354-364
Author(s):  
A. N. Irkitova ◽  
A. V. Grebenshchikova ◽  
A. V. Matsyura
Keyword(s):  
Escherichia Coli ◽  
Bacillus Subtilis ◽  
Wild Strain ◽  
Fish Farming ◽  
Antagonistic Activity ◽  
Antagonistic Effect ◽  
E Coli ◽  
Long Period ◽  
Test Culture ◽  
Agar Media

<p>An important link in solving the problem of healthy food is the intensification of the livestock, poultry and fish farming, which is possible only in the adoption and rigorous implementation of the concept of rational feeding of animals. In the implementation of this concept required is the application of probiotic preparations. Currently, there is an increased interest in spore probiotics. In many ways, this can be explained by the fact that they use no vegetative forms of the bacilli and their spores. This property provides spore probiotics a number of advantages: they are not whimsical, easily could be selected, cultivated, and dried. Moreover, they are resistant to various factors and could remain viable during a long period. One of the most famous spore microorganisms, which are widely used in agriculture, is <em>Bacillus subtilis</em>. Among the requirements imposed to probiotic microorganisms is mandatory – antagonistic activity to pathogenic and conditional-pathogenic microflora. The article presents the results of the analysis of antagonistic activity of collection strains of <em>B. subtilis</em>, and strains isolated from commercial preparations. We studied the antagonistic activity on agar and liquid nutrient medias to trigger different antagonism mechanisms of <em>B. subtilis</em>. On agar media, we applied three diffusion methods: perpendicular bands, agar blocks, agar wells. We also applied the method of co-incubating the test culture (<em>Escherichia coli</em>) and the antagonist (or its supernatant) in the nutrient broth. Our results demonstrated that all our explored strains of <em>B. subtilis</em> have antimicrobial activity against a wild strain of <em>E. coli</em>, but to varying degrees. We identified strains of <em>B. subtilis</em> with the highest antagonistic effect that can be recommended for inclusion in microbial preparations for agriculture.</p><p><em><br /></em><em></em></p>

Антимікробна резистентність провідних збудників інфекцій сечових шляхів у Києві (Україна)

2017 ◽  
Vol 1 (2) ◽  
pp. 48-60
Author(s):  
A.G. Salmanov ◽  
A.V. Rudenko
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Klebsiella Pneumoniae ◽  
Staphylococcus Epidermidis ◽  
Klebsiella Oxytoca ◽  
Enterobacter Aerogenes ◽  
Enterobacter Cloacae ◽  
Proteus Vulgaris ◽  
Providencia Rettgeri ◽  
E Coli

Мета роботи — вивчити резистентність до антибіотиків бактеріальних збудників інфекцій сечових шляхів (ІСШ), виділених у пацієнтів урологічного стаціонару в м. Києві. Матеріали і методи. Досліджено 1612 штамів бактерій, виділених із сечі хворих з ІСШ (цистит, уретрит, пієлонефрит), госпіталізованих в урологічне відділення ДУ «Інститут урології НАМН України» у м. Києві протягом 2016 р. Серед пацієнтів переважали жінки — 1201 (74,5 %). Вік хворих становив від 17 до 74 років. Для збору даних використано медичну документацію лікарні. Мікробіологічні дослідження виконано у лабораторії мікробіології ДУ «Інститут урології НАМН України». Аналізували результати культурального дослідження зразків сечі, зібраних за наявності клінічних ознак ІСШ. Дослідження клінічного матеріалу та інтерпретацію отриманих результатів проводили загальноприйнятими методами. Вивчено чутливість уропатогенів до 31 антибіотика дискодифузійним методом відповідно до рекомендацій Інституту клінічних та лабораторних стандартів США (Clinical and Laboratory Standards Institute (CLSI)). Результати та обговорення. Аналіз мікробного спектра сечі виявив домінування серед уропатогенів штамів Escherichia coli (32,0 %), Enterococcus faecalis (19,5 %), Klebsiella pneumoniae (10,9 %), Staphylococcus epidermidis (8,9 %), S. haemolyticus (6,5 %) та Pseudomonas aeruginosa (6,4 %). Частка Enterococcus faecium, Enterobacter aerogenes і Streptococcus viridans становила відповідно 2,5, 2,2 і 1,6 %, Enterobacter cloacae, Klebsiella oxytoca, Acinetobacter baumannii, Proteus vulgaris та Providencia rettgeri — менше 1,0 %. У більшості випадків (69,7 %) мікроорганізми виділено у монокультурі, у решті випадків — у мікробних асоціа- ціях. Високу резистентність до тестованих антибіотиків виявили штами E. aerogenes (45,1 %), E. cloacae (45,7 %), E. faecium (40,9 %), E. faecalis (40,7 %), E. coli (39,9 %), P. aeruginosa (34,0 %), K. pneumoniae (28,6 %). Найбільш активними до уропатогенів були іміпенем (E. coli — 87,6 %, P. aeruginosa — 75,7 %, E. cloacae — 67,3 %, E. aerogenes — 72,6 %, K. pneumoniae — 93,2 %), меропенем (E. coli — 89,1 %, P. aeruginosa — 76,7 %, K. pneumoniae — 82,6 %), лефлоцин (E. coli — 74,5 %, ентерококи — 78,7 %, P. aeruginosa — 76,7 %, E. cloacae — 73,9 %, E. aerogenes — 80,4 %, K. pneumoniae — 83,5 %), амоксицилін/клавуланат (ентерококи — 84,6 %), фурагін (ентерококи — 82,6 %), цефоперазон (K. pneumoniae — 89,2 %, P. aeruginosa — 73,8 %), цефтріаксон (K. pneumoniae — 80,1 %). Висновки. Антибіотикорезистентність збудників ІСШ — важлива терапевтична проблема. Найбільшою активністю до уропатогенів характеризуються іміпенем, меропенем, лефлоцин, амоксицилін/ клавуланат, фурагін, цефоперазон, цефтріаксон, які можна розглядати як препарат вибору для призначення стартової терапії ІСШ. Необхідно здійснювати постійний моніторинг за резистентністю до дії антибіотиків. Політику використання антибіотиків у кожному стаціонарі слід визначати залежно від локальних даних щодо резистентності до протимікробних препаратів.

Synthesis of Chalcones and Nucleosides Incorporating [1, 3, 4]Oxadiazolenone Core and Evaluation of their Antifungal and Antibacterial Activities

2020 ◽  
Vol 15 (6) ◽  
pp. 665-679
Author(s):  
Alok K. Srivastava ◽  
Lokesh K. Pandey
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Bacillus Subtilis ◽  
Antifungal Activity ◽  
Aspergillus Niger ◽  
Gram Negative ◽  
E Coli ◽  
Gram Positive Bacteria ◽  
Good Antibacterial Activity

Background: [1, 3, 4]oxadiazolenone core containing chalcones and nucleosides were synthesized by Claisen-Schmidt condensation of a variety of benzaldehyde derivatives, obtained from oxidation of substituted 5-(3/6 substituted-4-Methylphenyl)-1, 3, 4-oxadiazole-2(3H)-one and various substituted acetophenone. The resultant chalcones were coupled with penta-O-acetylglucopyranose followed by deacetylation to get [1, 3, 4] oxadiazolenone core containing chalcones and nucleosides. Various analytical techniques viz IR, NMR, LC-MS and elemental analysis were used to confirm the structure of the synthesised compounds.The compounds were targeted against Bacillus subtilis, Staphylococcus aureus and Escherichia coli for antibacterial activity and Aspergillus flavus, Aspergillus niger and Fusarium oxysporum for antifungal activity. Methods: A mixture of Acid hydrazides (3.0 mmol) and N, Nʹ- carbonyl diimidazole (3.3 mmol) in 15 mL of dioxane was refluxed to afford substituted [1, 3, 4]-oxadiazole-2(3H)-one. The resulted [1, 3, 4]- oxadiazole-2(3H)-one (1.42 mmol) was oxidized with Chromyl chloride (1.5 mL) in 20 mL of carbon tetra chloride and condensed with acetophenones (1.42 mmol) to get chalcones 4. The equimolar ratio of obtained chalcones 4 and β -D-1,2,3,4,6- penta-O-acetylglucopyranose in presence of iodine was refluxed to get nucleosides 5. The [1, 3, 4] oxadiazolenone core containing chalcones 4 and nucleosides 5 were tested to determined minimum inhibitory concentration (MIC) value with the experimental procedure of Benson using disc-diffusion method. All compounds were tested at concentration of 5 mg/mL, 2.5 mg/mL, 1.25 mg/mL, 0.62 mg/mL, 0.31 mg/mL and 0.15 mg/mL for antifungal activity against three strains of pathogenic fungi Aspergillus flavus (A. flavus), Aspergillus niger (A. niger) and Fusarium oxysporum (F. oxysporum) and for antibacterial activity against Gram-negative bacterium: Escherichia coli (E. coli), and two Gram-positive bacteria: Staphylococcus aureus (S. aureus) and Bacillus subtilis(B. subtilis). Result: The chalcones 4 and nucleosides 5 were screened for antibacterial activity against E. coli, S. aureus and B. subtilis whereas antifungal activity against A. flavus, A. niger and F. oxysporum. Compounds 4a-t showed good antibacterial activity whereas compounds 5a-t containing glucose moiety showed better activity against fungi. The glucose moiety of compounds 5 helps to enter into the cell wall of fungi and control the cell growth. Conclusion: Chalcones 4 and nucleosides 5 incorporating [1, 3, 4] oxadiazolenone core were synthesized and characterized by various spectral techniques and elemental analysis. These compounds were evaluated for their antifungal activity against three fungi; viz. A. flavus, A. niger and F. oxysporum. In addition to this, synthesized compounds were evaluated for their antibacterial activity against gram negative bacteria E. Coli and gram positive bacteria S. aureus, B. subtilis. Compounds 4a-t showed good antibacterial activity whereas 5a-t showed better activity against fungi.

scholarly journals High-density transposon libraries utilising outward-oriented promoters identify mechanisms of action and resistance to antimicrobials

2020 ◽  
Vol 367 (22) ◽  
Author(s):  
Chris Coward ◽  
Gopujara Dharmalingham ◽  
Omar Abdulle ◽  
Tim Avis ◽  
Stephan Beisken ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Pathogenic Bacteria ◽  
Selective Advantage ◽  
Mechanisms Of Action ◽  
Over Expression ◽  
E Coli ◽  
Synthase Inhibitor ◽  
Established Technique ◽  
Bacterial Transposon

ABSTRACT The use of bacterial transposon mutant libraries in phenotypic screens is a well-established technique for determining which genes are essential or advantageous for growth in conditions of interest. Standard, inactivating, transposon libraries cannot give direct information about genes whose over-expression gives a selective advantage. We report the development of a system wherein outward-oriented promoters are included in mini-transposons, generation of transposon mutant libraries in Escherichia coli and Pseudomonas aeruginosa and their use to probe genes important for growth under selection with the antimicrobial fosfomycin, and a recently-developed leucyl-tRNA synthase inhibitor. In addition to the identification of known mechanisms of action and resistance, we identify the carbon–phosphorous lyase complex as a potential resistance liability for fosfomycin in E. coli and P. aeruginosa. The use of this technology can facilitate the development of novel mechanism-of-action antimicrobials that are urgently required to combat the increasing threat worldwide from antimicrobial-resistant pathogenic bacteria.

scholarly journals Fabrication of a Novel AgBr/Ag2MoO4@InVO4 Composite with Excellent Visible Light Photocatalytic Property for Antibacterial Use

Nanomaterials ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1541
Author(s):  
Jie Zhang ◽  
Jia Wang ◽  
Qingjun Zhu ◽  
Binbin Zhang ◽  
Huihui Xu ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Degradation Rate ◽  
Photocatalytic Property ◽  
Photocatalytic Reaction ◽  
Composite Photocatalyst ◽  
E Coli ◽  
Radical Trapping ◽  
Visible Light Photocatalytic

A novel AgBr/Ag2MoO4@InVO4 composite photocatalyst with different heterojunction structures was successfully constructed by compounding InVO4 with Ag2MoO4 and AgBr. According to the degradation, antibacterial and free radical trapping data, the photocatalytic antibacterial and antifouling activities of AgBr/Ag2MoO4@InVO4 composite were evaluated, and the corresponding photocatalytic reaction mechanism was proposed. Adding AgBr/Ag2MoO4@InVO4 composite, the degradation rate of ciprofloxacin (CIP) achieved 95.5% within 120 min. At the same time, the antibacterial rates of Escherichia coli (E. coli), Staphylococcus aureus (S. aureus) and Pseudomonas aeruginosa (P. aeruginosa) achieved 99.99%. The AgBr/Ag2MoO4@InVO4 composite photocatalyst showed promising usage in photocatalytic antibacterial and purification areas.

scholarly journals Artificial Septal Targeting of Bacillus subtilis Cell Division Proteins in Escherichia coli: an Interspecies Approach to the Study of Protein-Protein Interactions in Multiprotein Complexes

2008 ◽  
Vol 190 (18) ◽  
pp. 6048-6059 ◽  
Author(s):  
Carine Robichon ◽  
Glenn F. King ◽  
Nathan W. Goehring ◽  
Jon Beckwith
Keyword(s):  
Escherichia Coli ◽  
Bacillus Subtilis ◽  
Cell Division ◽  
Protein Interactions ◽  
Fluorescent Protein ◽  
Bacterial Cell Division ◽  
Protein Protein Interactions ◽  
Positive Interaction ◽  
E Coli ◽  
Multiprotein Complexes

ABSTRACT Bacterial cell division is mediated by a set of proteins that assemble to form a large multiprotein complex called the divisome. Recent studies in Bacillus subtilis and Escherichia coli indicate that cell division proteins are involved in multiple cooperative binding interactions, thus presenting a technical challenge to the analysis of these interactions. We report here the use of an E. coli artificial septal targeting system for examining the interactions between the B. subtilis cell division proteins DivIB, FtsL, DivIC, and PBP 2B. This technique involves the fusion of one of the proteins (the “bait”) to ZapA, an E. coli protein targeted to mid-cell, and the fusion of a second potentially interacting partner (the “prey”) to green fluorescent protein (GFP). A positive interaction between two test proteins in E. coli leads to septal localization of the GFP fusion construct, which can be detected by fluorescence microscopy. Using this system, we present evidence for two sets of strong protein-protein interactions between B. subtilis divisomal proteins in E. coli, namely, DivIC with FtsL and DivIB with PBP 2B, that are independent of other B. subtilis cell division proteins and that do not disturb the cytokinesis process in the host cell. Our studies based on the coexpression of three or four of these B. subtilis cell division proteins suggest that interactions among these four proteins are not strong enough to allow the formation of a stable four-protein complex in E. coli in contrast to previous suggestions. Finally, our results demonstrate that E. coli artificial septal targeting is an efficient and alternative approach for detecting and characterizing stable protein-protein interactions within multiprotein complexes from other microorganisms. A salient feature of our approach is that it probably only detects the strongest interactions, thus giving an indication of whether some interactions suggested by other techniques may either be considerably weaker or due to false positives.

Toxicity of the First Ten MEIC Chemicals to Bacteria

1993 ◽  
Vol 21 (2) ◽  
pp. 151-155
Author(s):  
Gustaw Kerszman
Keyword(s):  
Escherichia Coli ◽  
Bacillus Subtilis ◽  
Linear Regression ◽  
Minimal Inhibitory Concentration ◽  
Blood Concentration ◽  
Inhibitory Concentration ◽  
Human Lymphocytes ◽  
Bacterial Species ◽  
E Coli ◽  
Mild Toxicity

The toxicity of the first ten MEIC chemicals to Escherichia coli and Bacillus subtilis was examined. Nine of the chemicals were toxic to the bacteria, with the minimal inhibitory concentration (MIC) ranging from 10-3 to 4.4M. The sensitivities of both organisms were similar, but the effect on E. coli was often bactericidal, while it was bacteriostatic for B. subtilis. Digoxin was not detectably toxic to either bacterial species. Amitriptyline and FeSO4 were relatively less toxic to the bacteria than to human cells. For seven chemicals, a highly significant linear regression was established between log MIC in bacteria and log of blood concentration, giving lethal and moderate/mild toxicity in humans, as well as with toxicity to human lymphocytes.

scholarly journals Identification and Characterization of Genes Required for 5-Hydroxyuridine Synthesis in Bacillus subtilis and Escherichia coli tRNA

2019 ◽  
Vol 201 (20) ◽  
Author(s):  
Charles T. Lauhon
Keyword(s):  
Escherichia Coli ◽  
Bacillus Subtilis ◽  
Genomic Context ◽  
Similar Reduction ◽  
Content Type ◽  
E Coli ◽  
Wobble Position ◽  
Fertile Ground ◽  
And Function

ABSTRACT In bacteria, tRNAs that decode 4-fold degenerate family codons and have uridine at position 34 of the anticodon are typically modified with either 5-methoxyuridine (mo5U) or 5-methoxycarbonylmethoxyuridine (mcmo5U). These modifications are critical for extended recognition of some codons at the wobble position. Whereas the alkylation steps of these modifications have been described, genes required for the hydroxylation of U34 to give 5-hydroxyuridine (ho5U) remain unknown. Here, a number of genes in Escherichia coli and Bacillus subtilis are identified that are required for wild-type (wt) levels of ho5U. The yrrMNO operon is identified in B. subtilis as important for the biosynthesis of ho5U. Both yrrN and yrrO are homologs to peptidase U32 family genes, which includes the rlhA gene required for ho5C synthesis in E. coli. Deletion of either yrrN or yrrO, or both, gives a 50% reduction in mo5U tRNA levels. In E. coli, yegQ was found to be the only one of four peptidase U32 genes involved in ho5U synthesis. Interestingly, this mutant shows the same 50% reduction in (m)cmo5U as that observed for mo5U in the B. subtilis mutants. By analyzing the genomic context of yegQ homologs, the ferredoxin YfhL is shown to be required for ho5U synthesis in E. coli to the same extent as yegQ. Additional genes required for Fe-S biosynthesis and biosynthesis of prephenate give the same 50% reduction in modification. Together, these data suggest that ho5U biosynthesis in bacteria is similar to that of ho5C, but additional genes and substrates are required for complete modification. IMPORTANCE Modified nucleotides in tRNA serve to optimize both its structure and function for accurate translation of the genetic code. The biosynthesis of these modifications has been fertile ground for uncovering unique biochemistry and metabolism in cells. In this work, genes that are required for a novel anaerobic hydroxylation of uridine at the wobble position of some tRNAs are identified in both Bacillus subtilis and Escherichia coli. These genes code for Fe-S cluster proteins, and their deletion reduces the levels of the hydroxyuridine by 50% in both organisms. Additional genes required for Fe-S cluster and prephenate biosynthesis and a previously described ferredoxin gene all display a similar reduction in hydroxyuridine levels, suggesting that still other genes are required for the modification.

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