scholarly journals The mineralosphere—interactive zone of microbial colonization and carbon use in grassland soils

2021 ◽  
Author(s):  
Runa S. Boeddinghaus ◽  
Sven Marhan ◽  
Aurelia Gebala ◽  
Heike Haslwimmer ◽  
Selma Vieira ◽  
...  
Keyword(s):  
Root Exudates ◽  
Heavy Rain ◽  
Microbial Colonization ◽  
Gram Negative Bacteria ◽  
Grassland Soils ◽  
Gram Positive ◽  
Gram Negative ◽  
Bacterial Phyla ◽  
Gram Positive Bacteria ◽  
Bacteria And Fungi

AbstractTo improve our understanding of early microbial colonization of pristine minerals and their group-specific C utilization, we exposed minerals (illite/goethite/quartz) amended with artificial root exudates (ARE, glucose, and citric acid) in grassland soils for a period of 24 weeks. FTIR spectra indicated that mineral-associated ARE were used within the first 2 weeks of exposure and were replaced by other carbohydrates derived from living or dead cells as well as soil-borne C sources transported into the mineralosphere after heavy rain events. Fungi and Gram-positive bacteria incorporated ARE-derived C more rapidly than Gram-negative bacteria. Gram-negative bacteria presumably profited indirectly from the ARE by cross-feeding on mineral-associated necromass of fungi and Gram-positive bacteria. The Gram-negative bacterial phyla Verrucomicrobia, Planctomycetes, Gemmatimonadetes, Armatimonadetes, and Chloroflexi showed a positive correlation with Gram-negative PLFA abundances. After 24 weeks of exposure in the grassland soils, abundances of soil microorganisms in the mineralosphere reached only 3.1% of the population density in soil. In conclusion, both bacteria and fungi slowly colonize new surfaces such as pristine minerals, but quickly assimilate artificial root exudates, creating an active microbial community in the mineralosphere.

scholarly journals Bacterial Colonization of Disposable Soft Contact Lenses Is Greater during Corneal Infiltrative Events than during Asymptomatic Extended Lens Wear

2000 ◽  
Vol 38 (12) ◽  
pp. 4420-4424 ◽  
Author(s):  
Padmaja R. Sankaridurg ◽  
Savitri Sharma ◽  
Mark Willcox ◽  
Thomas J. Naduvilath ◽  
Deborah F. Sweeney ◽  
...  
Keyword(s):  
Risk Factor ◽  
Contact Lenses ◽  
Microbial Colonization ◽  
Gram Negative Bacteria ◽  
Soft Contact ◽  
Gram Positive ◽  
Gram Negative ◽  
Soft Contact Lenses ◽  
Gram Positive Bacteria ◽  
Lens Wear

Microorganisms, especially gram-negative bacteria, are considered to play a role in the etiology of certain corneal infiltrative events (CIEs) observed during soft contact lens wear. This study explored the possibility of microbial colonization of soft contact lenses as a risk factor leading to CIEs. In a clinical trial conducted from March 1993 to January 1996, 330 subjects wore disposable soft contact lenses on a 6-night extended-wear and disposal schedule. During this period, 4,321 lenses (118 during CIEs; 4,203 during asymptomatic lens wear) were recovered aseptically and analyzed for microbial colonization. A greater percentage of lenses were free from microbial colonization during asymptomatic wear than during CIEs (42 versus 23%;P < 0.0001). The incidence of gram-positive bacteria, gram-negative bacteria and fungi was greater during CIEs than during asymptomatic lens wear (P < 0.05). During asymptomatic lens wear, gram-positive bacteria were isolated most frequently and were usually normal external ocular microbiota. Of the gram-positive bacteria, the incidence of Streptococcus pneumoniae was greater during CIE than during asymptomatic wear (7.6 versus 0.6%; P < 0.0001). While gram-negative bacteria were seen in few cases during asymptomatic wear, their incidence during CIE in comparison to asymptomatic wear was substantial and significant (23.7 versus 3.8%; P < 0.0001). Also, the level of colonization was high. Of CIEs, events of microbial keratitis, contact lens acute red eye, and asymptomatic infiltrative keratitis were associated with lens colonization with gram-negative bacteria or S. pneumoniae. Colonization of soft contact lenses with pathogenic bacteria, especially gram-negative bacteria andS. pneumoniae, appears to be a significant risk factor leading to CIE.

scholarly journals Synthesis and Preliminary Biological Activity Evaluation of New N- Substituted Phthalimide Derivatives

2020 ◽  
Vol 29 (1) ◽  
pp. 247-252
Author(s):  
Halah A. Sahib ◽  
Mohammed H. Mohammed
Keyword(s):  
Antimicrobial Activity ◽  
Methyl Ester ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Ft Ir ◽  
Bacteria And Fungi ◽  
Phenylalanine Methyl Ester

A A new series of bases of Schiff (H2-H4) derived from phthalic anhydrideweresynthesized. These Schiff bases were prepared by the reaction of different amines (tyrosine methyl ester, phenylalanine methyl ester, and isoniazid) with the phthalimide derived aldehyde with the aid of glacial acetic acid or triethylamine ascatalysts. All the synthesized compounds were characterized by (FT-IR and 1HNMR) analyses and were in vitro evaluated for their antimicrobial activity against six various kinds of microorganisms. All the synthesized compounds had been screened for their antimicrobial activity against two Gram-positive bacteria “Staph. Aureus, and Bacillus subtilis”, two Gram-negative bacteria “Escherichia coli, and Klebsiella pneumoniae”, and two fungi species “Candida tropicalis and Candida albicans” using concentrations of 62.5, 125 and 250 µg\mLof derivative in dimethyl sulfoxide(DMSO). All the synthesized compounds showed no activity at all against Gram-positive bacteria, for Gram-negative bacteria and fungi they showed moderate or no activity except compound H1revealedhigh antifungal activityagainstCandida tropicalisat concentrations 125 and 250 µg\ mL. Keywords: Schiff base, phthalic anhydride, antimicrobial.  

scholarly journals One stone, three birds: one AIEgen with three colors for fast differentiation of three pathogens

2020 ◽  
Vol 11 (18) ◽  
pp. 4730-4740 ◽  
Author(s):  
Chengcheng Zhou ◽  
Meijuan Jiang ◽  
Jian Du ◽  
Haotian Bai ◽  
Guogang Shan ◽  
...  
Keyword(s):  
Rapid Identification ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Bacteria And Fungi

A simple AIEgen with three emission colors achieves rapid identification of Gram-negative bacteria, Gram-positive bacteria and fungi.

Selection of quorum quenching (QQ) bacteria for membrane biofouling control: effect of different Gram-staining QQ bacteria, Bacillus sp. T5 and Delftia sp. T6, on microbial population in membrane bioreactors

2018 ◽  
Vol 78 (2) ◽  
pp. 358-366 ◽  
Author(s):  
Bahar Yavuztürk Gül ◽  
Derya Yüksel Imer ◽  
Pyung-Kyu Park ◽  
Ismail Koyuncu
Keyword(s):  
Microbial Community ◽  
Quorum Quenching ◽  
Gram Negative Bacteria ◽  
Bacillus Sp ◽  
Control Effect ◽  
Gram Positive ◽  
Illumina Hiseq ◽  
Gram Negative ◽  
Bacterial Phyla ◽  
Gram Positive Bacteria

Abstract This study aimed to address the gap in understanding how the microbial community present within quorum quenching-membrane bioreactor (QQ-MBRs) changes during the operations by investigating the behavior of two different types of QQ bacteria, Bacillus sp. T5 and Delftia sp. T6. The anti-biofouling effects of T5 and T6 in the QQ-MBR were 85% and 76%, respectively. According to the Illumina HiSeq results, when the QQ-MBR was operated with Gram-positive bacteria, T5, in the mixed liquor a reduction was observed in Gram-positive bacteria and Gram-negative bacteria population increased. In contrast, when the QQ-MBR was operated with Gram-negative bacteria, T6, Gram-negative bacteria population reduced and an increase in Gram-positive bacteria observed. As such, the outputs of the Illumina analysis revealed that use of Gram-negative QQ bacteria in the reactor induced a Gram-positive microbial community and vice versa. This indicates that a close interaction occurs between indigenous Gram-negative and positive bacterial phyla, and Bacillus sp. T5/Delftia sp. T6 is fundamental to the performance of MBRs. This is the first study demonstrating such a relationship and assistance selecting QQ bacteria/strategy in an effective way.

Aerobic Isolates in Hemovac Lines

1980 ◽  
Vol 88 (2) ◽  
pp. 124-132 ◽  
Author(s):  
Milton G. Yoder ◽  
Joseph Silva
Keyword(s):  
Head And Neck ◽  
Postoperative Period ◽  
Drainage System ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Bacteria And Fungi ◽  
Head And Neck Infections

Positive aerobic isolates from hemovac lines were found in 41 of 68 patients (60%) who had major head and neck procedures requiring the hemovac drainage system during the postoperative period. When studied up to six days of placement, the number and the type of organisms in a hemovac system generally remained the same. A clue to impending infection was the isolation of two or more different genera from the hemovac system. Isolates from hemovac lines can frequently indicate the cause of the complication. Possible pathogens in postoperative head and neck infections include gram-positive bacteria, gram-negative bacteria, and fungi.

scholarly journals Synthesis and Evaluation of Some Coumarin Based Schiff's Bases as Potential Antimicrobial Agents'

2012 ◽  
Vol 9 (4) ◽  
pp. 2079-2088 ◽  
Author(s):  
Vishakha Bansode ◽  
Meenakshi N. Deodhar
Keyword(s):  
Antimicrobial Activity ◽  
Antimicrobial Agents ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
H Nmr ◽  
Nmr Data ◽  
Bacteria And Fungi

A series of the title compounds 3-(4-(4, 5-dihydro-5-(substituted phenyl)-1H-3-pyrazolyl) phenylimino) methyl)-4-chloro-2H-chromen-2-one 5(a-g) have been synthesized. These compounds were characterized on the basis of their spectral (IR,1H NMR) data and evaluated for antimicrobial activityin vitroagainst gram positive bacteria, gram negative bacteria and fungi. The compound (5b) was found to be the most active with MIC of 20 µg/ml against all the tested organisms.

Rapid demonstration of septic or infectious arthritis due to Gram-negative bacteria

1992 ◽  
Vol 50 (1) ◽  
pp. 686-687
Author(s):  
Jacob S. Hanker ◽  
Paul R. Gross ◽  
Beverly L. Giammara
Keyword(s):  
Chronic Arthritis ◽  
Blood Cultures ◽  
Gram Negative Bacteria ◽  
Infectious Arthritis ◽  
Bacterial Arthritis ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria

Blood cultures are positive in approximately only 50 per cent of the patients with nongonococcal bacterial infectious arthritis and about 20 per cent of those with gonococcal arthritis. But the concept that gram-negative bacteria could be involved even in chronic arthritis is well-supported. Gram stains are more definitive in staphylococcal arthritis caused by gram-positive bacteria than in bacterial arthritis due to gram-negative bacteria. In the latter situation where gram-negative bacilli are the problem, Gram stains are helpful for 50% of the patients; they are only helpful for 25% of the patients, however, where gram-negative gonococci are the problem. In arthritis due to gram-positive Staphylococci. Gramstained smears are positive for 75% of the patients.

Antibacterial activity of magnesium oxide nanoparticles prepared by Calcination method

2019 ◽  
Vol 10 (03) ◽  
Author(s):  
Elaf Ayad Kadhem ◽  
Miaad Hamzah Zghair ◽  
Sarah , Hussam H. Tizkam, Shoeb Alahmad Salih Mahdi ◽  
Hussam H. Tizkam ◽  
Shoeb Alahmad
Keyword(s):  
Antibacterial Activity ◽  
Magnesium Oxide ◽  
Diffusion Method ◽  
Oxide Nanoparticles ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Magnesium Oxide Nanoparticles ◽  
Agar Disc

magnesium oxide nanoparticles (MgO NPs) were prepared by simple wet chemical method using different calcination temperatures. The prepared NPs were characterized by Electrostatic Discharge (ESD), Scanning Electron Microscope (SEM) and X-ray Diffraction (XRD). It demonstrates sharp intensive peak with the increase of crystallinty and increase of the size with varying morphologies with respect to increase of calcination temperature. Antibacterial studies were done on gram negative bacteria (E.coli) and gram positive bacteria (S.aureus) by agar disc diffusion method. The zones of inhibitions were found larger for gram positive bacteria than gram negative bacteria, this mean, antibacterial MgO NPs activity more active on gram positive bacteria than gram negative bacteria because of the structural differences. It was found that antibacterial activity of MgO NPs was found it has directly proportional with their concentration.

BAKTERI PADA KARANG SCLERACTINIA DI KAWASAN PERAIRAN BUNAKEN, MOROTAI DAN RAJA AMPAT

2020 ◽  
Vol 8 (1) ◽  
pp. 122
Author(s):  
Eghbert Eghbert Elvan Eghbert Elvan Ampou ◽  
Iis Iis Triyulianti ◽  
Nuryani Widagti ◽  
Suciadi Catur Nugroho ◽  
Yuli Pancawati
Keyword(s):  
Scleractinian Coral ◽  
Gram Negative Bacteria ◽  
Hard Coral ◽  
Field Sampling ◽  
Bacterial Isolation ◽  
Gram Positive ◽  
Coral Mucus ◽  
Gram Negative ◽  
Gram Positive Bacteria

Research on hard coral (Scleractinian coral) contaminated with bacteria is still not much done, especially in Indonesian waters. This study took samples of coral mucus in 2010 at 3 (three) different locations, namely Bunaken (May); Morotai (September) and Raja Ampat (November), which focused on the analysis of Research on hard coral (Scleractinian coral) contaminated with bacteria is still not much done, especially in Indonesian waters. This study took samples of coral mucus in 2010 at 3 (three) different locations, namely Bunaken (May); Morotai (September) and Raja Ampat (November), which focused on the analysis of gram-positive and gram-negative bacteria. The method used for field sampling is time swim, which is by diving at a depth of 5-10 meters for ± 30 minutes and randomly taking samples of coral mucus using siring or by taking directly on corals (reef branching). Mucus samples were analyzed by bacterial isolation in the laboratory. The result shows that there were differences between gram-positive and gram-negative bacteria in the three research sites and that gram-positive bacteria were higher or dominant. Further research that can identify the bacteria species and explain its relationship to the ecosystem is highly recommended.Keywords: Bacteria, Scleractinian coral, gram-positive and -negative, Bunaken, Morotai, Raja Ampat  AbstrakPenelitian tentang karang keras (Scleractinian coral) yang terkontaminasi bakteri masih belum banyak dilakukan, terutama di perairan Indonesia. Penelitian ini mengambil sampel mucus karang pada tahun 2010 di 3 (tiga) lokasi berbeda, yakni Bunaken (Mei); Morotai (September) dan Raja Ampat (November), yang difokuskan pada analisis bakteri gram postif dan gram negatif. Metode yang digunakan untuk pengambilan sampel di lapangan adalah time swim, yaitu dengan penyelaman pada kedalaman 5-10 meter selama ±30 menit dan mengambil sampel mucus karang secara acak menggunakan siring atau dengan mengambil langsung pada karang (fraksi cabang). Sampel mucus dianalisis dengan cara isolasi bakteri di laboratorium. Hasil analisis menunjukkan bahwa ada perbedaan antara bakteri gram positif dan gram negative di tiga lokasi survei dan bakteri gram positif lebih tinggi atau dominan. Penelitian lebih lanjut yang dapat menentukan jenis bakteri serta menjelaskan hubungannya dengan ekosistem sangat disarankan untuk dilakukan.Kata Kunci : Bakteri, Scleractinian coral, gram positif dan negatif, Bunaken, Morotai, Raja Ampat

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