Diluted Luria-Bertani medium vs. sewage sludge as growth media: comparison of community structure and diversity in the culturable bacteria

Abstract Background A diverse community of microbes naturally exists on the phylloplane, the surface of leaves. It is one of the most prevalent microbial habitats on earth and bacteria are the most abundant members, living in communities that are highly dynamic. Today, one of the key challenges for microbiologists is to develop strategies to culture the vast diversity of microorganisms that have been detected in metagenomic surveys. Results We isolated bacteria from the phylloplane of Hedera helix (common ivy), a widespread evergreen, using five growth media: Luria–Bertani (LB), LB01, yeast extract–mannitol (YMA), yeast extract–flour (YFlour), and YEx. We also included a comparison with the uncultured phylloplane, which we showed to be dominated by Proteobacteria, Actinobacteria, Bacteroidetes, and Firmicutes. Inter-sample (beta) diversity shifted from LB and LB01 containing the highest amount of resources to YEx, YMA, and YFlour which are more selective. All growth media equally favoured Actinobacteria and Gammaproteobacteria, whereas Bacteroidetes could only be found on LB01, YEx, and YMA. LB and LB01 favoured Firmicutes and YFlour was most selective for Betaproteobacteria. At the genus level, LB favoured the growth of Bacillus and Stenotrophomonas, while YFlour was most selective for Burkholderia and Curtobacterium. The in vitro plant growth promotion (PGP) profile of 200 isolates obtained in this study indicates that previously uncultured bacteria from the phylloplane may have potential applications in phytoremediation and other plant-based biotechnologies. Conclusions This study gives first insights into the total bacterial community of the H. helix phylloplane, including an evaluation of its culturability using five different growth media. We further provide a collection of 200 bacterial isolates underrepresented in current databases, including the characterization of PGP profiles. Here we highlight the potential of simple strategies to obtain higher microbial diversity from environmental samples and the use of high-throughput sequencing to guide isolate selection from a variety of growth media.

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Bacterial agents affected bacterial community structure to mitigate greenhouse gas emissions during sewage sludge composting

Bioresource Technology ◽

10.1016/j.biortech.2021.125397 ◽

2021 ◽

pp. 125397

Author(s):

Shudan Xue ◽

Lina Zhou ◽

Minzheng Zhong ◽

Mukesh Kumar Awasthi ◽

Hui Mao

Keyword(s):

Community Structure ◽

Sewage Sludge ◽

Bacterial Community ◽

Greenhouse Gas Emissions ◽

Greenhouse Gas ◽

Bacterial Community Structure ◽

Gas Emissions ◽

Sludge Composting

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Insights into the role of earthworms on the optimization of microbial community structure during vermicomposting of sewage sludge by PLFA analysis

Waste Management ◽

10.1016/j.wasman.2018.08.041 ◽

2018 ◽

Vol 79 ◽

pp. 700-708 ◽

Cited By ~ 8

Author(s):

Chunhui Zhao ◽

Yong Wang ◽

Yue Wang ◽

Feijie Wu ◽

Jiageng Zhang ◽

...

Keyword(s):

Community Structure ◽

Microbial Community ◽

Sewage Sludge ◽

Microbial Community Structure ◽

Plfa Analysis

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Stability of β-lactam antibiotics in bacterial growth media

10.1101/2020.04.15.044123 ◽

2020 ◽

Cited By ~ 1

Author(s):

Rebecca Brouwers ◽

Hugh Vass ◽

Angela Dawson ◽

Tracey Squires ◽

Sharareh Tavaddod ◽

...

Keyword(s):

Aqueous Solution ◽

Minimum Inhibitory Concentration ◽

Growth Medium ◽

Bacterial Growth ◽

Half Life ◽

Inhibitory Concentration ◽

Luria Bertani ◽

Growth Media ◽

Rapid Degradation ◽

Degradation Rates

AbstractLaboratory assays such as MIC tests assume that antibiotic molecules are stable in the chosen growth medium - but rapid degradation has been observed for antibiotics including β-lactams under some conditions in aqueous solution. Degradation rates in bacterial growth medium are less well known. Here, we develop a ‘delay time bioassay’ that provides a simple way to estimate antibiotic stability in bacterial growth media. We use the bioassay to measure degradation half-lives of the β-lactam antibiotics mecillinam, aztreonam and cefotaxime in widely-used bacterial growth media based on MOPS and Luria-Bertani (LB) broth. We find that mecillinam degradation can occur rapidly, with a half-life as short as 2 hours in MOPS medium at 37°C and pH 7.4, and 4-5 hours in LB, but that adjusting the pH and temperature can increase its stability to a half-life around 6 hours without excessively perturbing growth. Aztreonam and cefotaxime were found to have half-lives longer than 6 hours in MOPS medium at 37°C and pH 7.4, but still shorter than the timescale of a typical minimum inhibitory concentration (MIC) assay. Taken together, our results suggest that care is needed in interpreting MIC tests and other laboratory growth assays for β-lactam antibiotics, since there may be significant degradation of the antibiotic during the assay.

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Co-Culture of Acinetobacter calcoaceticus-baumannii complex and Staphylococcus saprophyticus Supports Simple Point Contamination Model in Recent Cases of Transfusion-Related Sepsis

American Journal of Clinical Pathology ◽

10.1093/ajcp/aqaa137.025 ◽

2020 ◽

Vol 154 (Supplement_1) ◽

pp. S14-S14

Author(s):

Christopher Kerantzas ◽

Jacob Merwede ◽

Edward Snyder ◽

Jeanne Hendrickson ◽

Christopher Tormey ◽

...

Keyword(s):

Acinetobacter Calcoaceticus ◽

Storage Conditions ◽

Luria Bertani ◽

Growth Media ◽

Columbia Blood Agar ◽

Staphylococcus Saprophyticus ◽

Platelet Storage ◽

Solid Media ◽

Apheresis Platelets ◽

Transfusion Reactions

Abstract The CDC recently reported a series of four septic transfusion reactions across three states resulting from contamination of apheresis platelet products. The apheresis platelets were contaminated with strains of both Acinetobacter calcoaceticus-baumannii complex (ACBC) and Staphylococcus saprophyticus (Ss). Two of the reported septic transfusion reactions occurred at our institution. The CDC investigation showed that isolates of each species were genetically related and suggested a point source of contamination. However, the contamination of blood products with ACBC is rare and the co-occurrence of these two species in all four cases was unusual. We hypothesized that there was an augmentative interaction between the clinical isolates of ACBC and Ss from these cases that contributed to their repeated co-occurrence. To test this hypothesis, we compared the growth characteristics of ACBC and Ss when cultured together versus independently. We used isolates from the contaminated platelets for our studies and performed experiments using both solid and liquid growth media. Experiments on solid media assessed density of growth and macroscopic morphology after cross-streaking on Columbia Blood Agar (CBA) and Luria-Bertani (LB) agar. Experiments in liquid media assessed growth by CFU counts in LB broth, platelet-poor plasma, and apheresis platelets. Growth in apheresis platelets was performed using standard, room temperature blood bank platelet storage conditions. Results of these experiments showed a higher CFU concentration of Ss when co-cultured with ACBC in LB broth only after several days, as compared to Ss alone under the same conditions. Otherwise, there was no evidence of augmented growth by either CFU concentration or growth rate in LB broth, plasma, or platelets at other time points. Similarly, there was no evidence of augmented growth by colony density or morphology when cross-streaking strains on either CBA or LB agar. As a result, we conclude that the co-occurrence of these two species in platelets is likely a coincidence of the point contamination suggested by the CDC investigation and not the result of growth augmentation between the two species.

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Role of Viscoelasticity in Bacterial Killing by Antimicrobials in Differently GrownPseudomonas aeruginosaBiofilms

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.01972-18 ◽

2019 ◽

Vol 63 (4) ◽

Cited By ~ 9

Author(s):

René T. Rozenbaum ◽

Henny C. van der Mei ◽

Willem Woudstra ◽

Ed D. de Jong ◽

Henk J. Busscher ◽

...

Keyword(s):

Stress Relaxation ◽

Environmental Dna ◽

Luria Bertani ◽

Matrix Composition ◽

Growth Media ◽

Multiple Characteristic ◽

Bacterial Killing ◽

Time Constants ◽

Content Type ◽

Insoluble Polysaccharides

ABSTRACTPseudomonas aeruginosacolonizes the sputum of most adult cystic fibrosis patients, forming difficult-to-eradicate biofilms in which bacteria are protected in their self-produced extracellular polymeric substance (EPS) matrices. EPS provide biofilms with viscoelastic properties, causing time-dependent relaxation after stress-induced deformation, according to multiple characteristic time constants. These time constants reflect different biofilm (matrix) components. Since the viscoelasticity of biofilms has been related to antimicrobial penetration but not yet bacterial killing, this study aims to relate killing ofP. aeruginosa, in its biofilm mode of growth, by three antimicrobials to biofilm viscoelasticity.P. aeruginosabiofilms were grown for 18 h in a constant-depth film fermenter, with mucin-containing artificial sputum medium (ASM+), artificial sputum medium without mucin (ASM−), or Luria-Bertani (LB) broth; this yielded 100-μm-thick biofilms that differed in their amounts of matrix environmental DNA (eDNA) and polysaccharides. Low-load compression testing, followed by three-element Maxwell analyses, showed that the fastest relaxation component, associated with unbound water, was most important in LB-medium-grown biofilms. Slower components due to water with dissolved polysaccharides, insoluble polysaccharides, and eDNA were most important in the relaxation of ASM+-grown biofilms. ASM−-grown biofilms showed intermediate stress relaxation.P. aeruginosain LB-medium-grown biofilms was killed most by exposure to tobramycin, colistin, or an antimicrobial peptide, while ASM+provided the most protective matrix, with less water and most insoluble polysaccharides and eDNA. In conclusion, stress relaxation ofP. aeruginosabiofilms grown in different media revealed differences in matrix composition that, within the constraints of the antimicrobials and growth media applied, correlated with the matrix protection offered against different antimicrobials.

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Effects of Elevated Temperature on Performance and Microbial Community Structure in ASBR Treating Thermal-Hydrolyzed Sewage Sludge

Energy Procedia ◽

10.1016/j.egypro.2011.10.686 ◽

2011 ◽

Vol 11 ◽

pp. 3294-3303 ◽

Cited By ~ 1

Author(s):

Ouyang Er-ming ◽

Wang Wei

Keyword(s):

Community Structure ◽

Elevated Temperature ◽

Microbial Community ◽

Sewage Sludge ◽

Microbial Community Structure

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A simple procedure for elimination of fungal contamination for enumeration of iron-oxidizing bacteria from bioleaching matrix of sewage sludge

Canadian Journal of Microbiology ◽

10.1139/w05-043 ◽

2005 ◽

Vol 51 (8) ◽

pp. 637-641 ◽

Cited By ~ 3

Author(s):

X Y Gu ◽

Jonathan W.C Wong

Keyword(s):

Sewage Sludge ◽

Incubation Time ◽

Simple Procedure ◽

Fungal Growth ◽

Growth Media ◽

Fungal Contamination ◽

Simple Method ◽

Whatman Filter Paper ◽

Iron Oxidizing Bacteria ◽

Time Required

Enumeration of iron-oxidizing bacteria from the bioleaching matrix of sewage sludge is always confronted by fungal contamination. The objective of the present study was to find a reliable and simple method to remove fungal growth and to shorten the incubation time for facilitating enumeration of the iron-oxidizers from complex sludge samples. The results demonstrated that filtering the sludge sample through sterile No. 5 Whatman filter paper before serial dilution was effective in eliminating the fungal growth on agarose media. Both the counts and the incubation time required for enumeration were highly dependent on the medium pH, with maximum counts at pH 2.5–2.75. Medium prepared at pH values outside of this range led to lower counts and a longer lag time for colony formation. However, the introduction of heterotrophic microorganisms into the solid medium did not show further improvement in enumeration efficiency and shortening of the incubation period. By incorporating the optimal conditions obtained, the incubation time could be reduced to 7 and 10 d for pure cultures and sludge samples, respectively.Key words: Acidithiobacillus ferrooxidans, iron-based bioleaching process, growth media, sewage sludge.

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