Journal of Microbiology

Journal Article

Cr(VI) removal from aqueous solution by thermophilic denitrifying bacterium Chelatococcus daeguensis TAD1 in the presence of single and multiple heavy metals: Han Li , Shaobin Huang , Yongqing Zhang; J. Microbiol. 2016;54(9):602-610. Published online August 31, 2016; DOI: https://doi.org/10.1007/s12275-016-5295-5

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Abstract: Cr(VI) pollution is increasing continuously as a result of ongoing industrialization. In this study, we investigated the thermophilic denitrifying bacterium Chelatococcus daeguensis TAD1, isolated from the biofilm of a biotrickling filter used in nitrogen oxides (NOX) removal, with respect to its ability to remove Cr(VI) from an aqueous solution. TAD1 was capable of reducing Cr(VI) from an initial concentration of 10 mg/L to non-detectable levels over a pH range of 7–9 and at a temperature range of 30–50°C. TAD1 simultaneously removed both Cr(VI) and NO3 −-N at 50°C, when the pH was 7 and the initial Cr(VI) concentration was 15 mg/L. The reduction of Cr(VI) to Cr(III) correlated with the growth metabolic activity of TAD1. The presence of other heavy metals (Cu, Zn, and Ni) inhibited the ability of TAD1 to remove Cr(VI). The metals each individually inhibited Cr(VI) removal, and the extent of inhibition increased in a cooperative manner in the presence of a combination of the metals. The addition of biodegradable cellulose acetate microspheres (an adsorption material) weakened the toxicity of the heavy metals; in their presence, the Cr(VI) removal efficiency returned to a high level. The feasibility and applicability of simultaneous nitrate removal and Cr(VI) reduction by strain TAD1 is promising, and may be an effective biological method for the clean-up of wastewater.

Review

REVIEW] The Microbiology of Phosphorus Removal in Activated Sludge Processes-the Current State of Play: Robert J. Seviour , Simon McIlroy; J. Microbiol. 2008;46(2):115-124. Published online June 11, 2008; DOI: https://doi.org/10.1007/s12275-008-0051-0

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43 Citations

Abstract: This review discusses critically what we know and would like to know about the microbiology of phosphorus (P) removal in activated sludge systems. In particular, the description of the genome sequences of two strains of the polyphosphate accumulating organism found in these processes, Candidatus ‘Accumulibacter phosphatis’, allows us to address many of the previously unanswered questions relating to how these processes behave, and to raise new questions about the microbiology of P removal. This article attempts to be deliberately speculative, and inevitably subjective, but hopefully at the same time useful to those who have an active interest in these environmentally very important processes.

Research Support, Non-U.S. Gov'ts

Denaturing Gradient Gel Electrophoresis Analysis of Bacterial Populations in 5-Stage Biological Nutrient Removal Process with Step Feed System for Wastewater Treatment: Soo-Youn Lee , Hyeon-Guk Kim , Jong Bok Park , Yong Keun Park; J. Microbiol. 2004;42(1):1-8.; DOI: https://doi.org/2009 [pii]

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Abstract: Changes in the bacterial populations of a 5-stage biological nutrient removal (BNR) process, with a step feed system for wastewater treatment, were monitored by denaturing gradient gel electrophoresis (DGGE) of PCR-amplified 16S ribosomal DNA fragments. DGGE analysis indicated seasonal community changes were observed, however, community profiles of the total bacteria of each reactor showed only minor differences in the samples obtained from the same season. The number of major bands was higher in the summer samples, and decreased during the winter period, indicating that the microbial community structure became simpler at low temperatures. Since the nitrogen and phosphate removal efficiencies were highly maintained throughout the winter operation period, the bacteria which still remaining in the winter sample can be considered important, playing a key role in the present 5-stage BNR sludge. The prominent DGGE bands were excised, and sequenced to gain insight into the identities of the predominant bacterial populations present, and most were found to not be closely related to previously characterized bacteria. These data suggest the importance of culture independent methods for the quality control of wastewater treatment

Removal of Heavy Metals by an Enriched Consortium: Eun Young Lee , Joung Soo Lim , Kyung Hwan Oh , Jae Yeon Lee , Seog Ku Kim , Yoo Kyung Lee , Keun Kim; J. Microbiol. 2008;46(1):23-28.; DOI: https://doi.org/10.1007/s12275-007-0131-6

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11 Citations

Abstract: An enriched consortium obtained from lake-sediment was developed for the removal of heavy metals such as Cu, Pb, Cr, Ni, and Zn from heavy metal-contaminated water. The removal efficiency of heavy metals in a shaking condition was generally higher than that in the static state. After the fifteenth enrichment with assorted heavy metals, the removal efficiencies in the shaking and static condition at an average concentration of 100 mg/L of each heavy metal were approximately 99~100% and 95~100%, respectively, depending on the type of heavy metal. An aerobically grown, pure culture isolated from an enriched culture was analyzed by 16S rRNA sequencing and identified as Ralstonia sp. HM-1. This strain was found to remove various heavy metals with an efficiency of approximately 97~100% at an average concentration of 200 mg/L of each heavy metal.

Removal and Inactivation of Hepatitis A Virus during Manufacture of a High Purity Antihemophilic Factor VIII Concentrate from Human Plasma: In Seop Kim , Yong Woon Choi , Sung Rae Lee , Mahl Soon Lee , Ki Ho Huh , Soungmin Lee; J. Microbiol. 2001;39(1):67-73.

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Abstract: A validation study was conducted to evaluate the efficacy and mechanism of the cryo-precipitation, monoclonal anti-FVIIIc antibody (mAb) chromatography, Q-Sepharose chromatography, and lyophilization steps involved in the manufacture of high purity factor VIII (GreenMono) from human plasma, in the removal and/or inactivation of hepatitis A virus (HAV). Samples from the relevant stages of the production process were spiked with HAV and subjected to scale-down processes mimicking the manufacture of the high purity factor VIII concentrate. Samples were collected at each step and immediately titrated using a 50% tissue culture infectious dose (TCID50) and then the virus reduction factors were evaluated. HAV was effectively partitioned from factor VIII during cryo-precipitation with the log reduction factor of 3.2. The mAb chromatography was the most effective step for removal of HAV with the log reduction factor of ³4.3. HAV infectivity was not detected in the fraction of factor VIII, while most of HAV infectivity was recovered in the fractions of flow through and wash during mAb chromatography. Q-Sepharose chromatography showed the lowest efficacy for partitioning HAV with the log reduction factor of 0.7. Lyophilization was an effective step in inactivating HAV with the log reduction factor of 2.3. The cumulative log reduction factor, ³10.5, achieved for the entire manufacturing process was several magnitudes greater than the potential HAV load of current plasma pools.

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