Enumeration of heterotrophic bacteria in water for dialysis: comparison of the efficiency of Reasoner'2 agar and plate count agar

Bugno, Adriana; Almodóvar, Adriana Aparecida Buzzo; Pereira, Tatiana Caldas

doi:10.1590/s1517-83822010000100003

Cited by 10 publications

(5 citation statements)

References 18 publications

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“…A substantial increase in the number of viable bacteria recovered were observed when R2A + CE rather than TSA + CE was used as the primary plating medium for enumerating the viable bacteria present. Enhanced recovery using R2A + CE has been observed by others sampling liquid environments in which methylobacteria were isolated [ 1 , 17 , 21 ]. Enhanced recovery was not evident when plating samples obtained from the copper coupons.…”

Section: Discussionmentioning

confidence: 95%

Characterization and Control of the Microbial Community Affiliated with Copper or Aluminum Heat Exchangers of HVAC Systems

et al. 2012

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Microbial growth in heating ventilation and air-conditioning (HVAC) systems with the subsequent contamination of indoor air is of increasing concern. Microbes and the subsequent biofilms grow easily within heat exchangers. A comparative study where heat exchangers fabricated from antimicrobial copper were evaluated for their ability to limit microbial growth was conducted using a full-scale HVAC system under conditions of normal flow rates using single-pass outside air. Resident bacterial and fungal populations were quantitatively assessed by removing triplicate sets of coupons from each exchanger commencing the fourth week after their installation for the next 30 weeks. The intrinsic biofilm associated with each coupon was extracted and characterized using selective and differential media. The predominant organisms isolated from aluminum exchangers were species of Methylobacterium of which at least three colony morphologies and 11 distinct PFGE patterns we found; of the few bacteria isolated from the copper exchangers, the majority were species of Bacillus. The concentrations and type of bacteria recovered from the control, aluminum, exchangers were found to be dependent on the type of plating media used and were 11,411–47,257 CFU cm−2 per coupon surface. The concentration of fungi was found to average 378 CFU cm−2. Significantly lower concentrations of bacteria, 3 CFU cm−2, and fungi, 1 CFU cm−2, were recovered from copper exchangers regardless of the plating media used. Commonly used aluminum heat exchangers developed stable, mixed, bacterial/fungal biofilms in excess of 47,000 organisms per cm2 within 4 weeks of operation, whereas the antimicrobial properties of metallic copper were able to limit the microbial load affiliated with the copper heat exchangers to levels 99.97 % lower during the same time period.

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Section: Discussionmentioning

confidence: 95%

Characterization and Control of the Microbial Community Affiliated with Copper or Aluminum Heat Exchangers of HVAC Systems

et al. 2012

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“…A mixture of bacteria (mixed liquor) procured from a local wastewater treatment (WWTP) facility was 10‐fold serially diluted in 0.85% w/v saline before spread plating on 1% R2A agar (0.5 g/L protease peptone, 0.5 g/L yeast extract, 0.3 g/L K 2 HPO 4 , 0.05 g/L MgSO 4 ·7H 2 O, pH 7) containing 50 μg/mL kanamycin (Fischer Scientific, Pittsburgh, PA) (Reasoner et al, ; Bugno et al, ). The WWTP is a trickling filter/solid contact type of facility with a design capacity of 75 million gallon per day (MGD).…”

Section: Methodsmentioning

confidence: 99%

Bacteriophage therapy for membrane biofouling in membrane bioreactors and antibiotic‐resistant bacterial biofilms

Bhattacharjee

Choi

Motlagh

et al. 2015

Biotech & Bioengineering

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To demonstrate elimination of bacterial biofilm on membranes to represent wastewater treatment as well as biofilm formed by antibiotic-resistant bacterial (ARB) to signify medical application, an antibiotic-resistant bacterium and its lytic bacteriophage were isolated from a full-scale wastewater treatment plant. Based on gram staining and complete 16 S rDNA sequencing, the isolated bacterium showed a more than 99% homology with Delftia tsuruhatensis, a gram-negative bacterium belonging to β-proteobacteria. The Delftia lytic phage's draft genome revealed the phage to be an N4-like phage with 59.7% G + C content. No transfer RNAs were detected for the phage suggesting that the phage is highly adapted to its host Delftia tsuruhatensis ARB-1 with regard to codon usage, and does not require additional tRNAs of its own. The gene annotation of the Delftia lytic phage found three different components of RNA polymerase (RNAP) in the genome, which is a typical characteristic of N4-like phages. The lytic phage specific to D. tsuruhatensis ARB-1 could successfully remove the biofilm formed by it on a glass slide. The water flux through the membrane of a prototype lab-scale membrane bioreactor decreased from 47 L/h m(2) to ∼15 L/h m(2) over 4 days due to a biofilm formed by D. tsuruhatensis ARB-1. However, the flux increased to 70% of the original after the lytic phage application. Overall, this research demonstrated phage therapy's great potential to solve the problem of membrane biofouling, as well as the problems posed by pathogenic biofilms in external wounds and on medical instruments.

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“…Strain 80 T was originally isolated from a woodland soil sample collected from the Altay area, Xinjiang Uyghur Autonomous Region, PR China. The soil sample was suspended in sterile water before serially 10× dilution and spread on Reasoner’s 2A agar medium plates [12] (g l −1 : yeast extract, 0.5; peptone, 0.5; casein hydrolysate, 0.5; glucose, 0.5; starch, 0.5; K 2 HPO 4 , 0.3; MgSO 4 , 0.024; sodium pyruvate, 0.3; and agar, 15; pH 7.5) with 10 % NaCl. Strain 80 T was isolated after 7 days of incubation at 30 °C.…”

Section: Isolation and Ecologymentioning

confidence: 99%

Radiobacillus kanasensis sp. nov., a halotolerant bacterium isolated from woodland soil

Zhang

Huang

Wang

et al. 2023

International Journal of Systematic and Evolutionary Microbiology

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A novel Gram-positive, aerobic, rod-shaped, non-motile, endospore-forming salt-tolerant bacterium strain (80T), was isolated from woodland soil collected near Kanas lake in the Altay region of Xinjiang, PR China. The strain grew at 15−45 °C, pH6.0–9.0 and with 0–14 % (w/v) NaCl. The complete genome size of the novel strain was 4 031 766 bp including a circle chromosome and a circle plasmid. The genomic DNA G+C content was 38.99 mol %. Phylogenetic analysis based on 16S rRNA gene sequence and genome showed that strain 80T has the highest similarity to Radiobacillus deserti TKL69T. However, the novel strain showed an average nucleotide identity value of 78.65 % (lower than 95 %) and a digital DNA–DNA hybridization value of 22.30 % with R. deserti TKL69T based on the genome sequences. The major fatty acids were anteiso-C15 : 0, iso-C15 : 0, anteiso-C17:0 and C16 : 1 ω7c alcohol. The only respiratory quinone was MK-7. The cell wall peptidoglycan was meso-diaminopimelic acid. Diphosphatidylglycerol, phosphatidylglycerol, one unidentified phospholipid, one unidentified aminophospholipid and two unidentified glycolipids were identified as the major polar lipids. The phylogenetic, phenotypic and chemotaxonomic analyses showed that strain 80T represents a novel species of the genus Radiobacillus and the name Radiobacillus kanasensis sp. nov. is proposed. The type strain is 80T (=GDMCC 1.2844T=JCM 35077T).

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Enumeration of heterotrophic bacteria in water for dialysis: comparison of the efficiency of Reasoner'2 agar and plate count agar

Cited by 10 publications

References 18 publications

Characterization and Control of the Microbial Community Affiliated with Copper or Aluminum Heat Exchangers of HVAC Systems

Characterization and Control of the Microbial Community Affiliated with Copper or Aluminum Heat Exchangers of HVAC Systems

Bacteriophage therapy for membrane biofouling in membrane bioreactors and antibiotic‐resistant bacterial biofilms

Radiobacillus kanasensis sp. nov., a halotolerant bacterium isolated from woodland soil

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