Journal of Microbiology

Volume 51(1); February 2013

Review

MINIREVIEW] Toxin-producing Cyanobacteria in Freshwater: A Review of the Problems, Impact on Drinking Water Safety, and Efforts for Protecting Public Health: Melissa Y. Cheung , Song Liang , Jiyoung Lee; J. Microbiol. 2013;51(1):1-10. Published online March 2, 2013; DOI: https://doi.org/10.1007/s12275-013-2549-3

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181 Citations

Abstract: Cyanobacteria have adapted to survive in a variety of environments and have been found globally. Toxin-producing cyanobacterial harmful algal blooms (CHABs) have been increasing in frequency worldwide and pose a threat to drinking and recreational water. In this study, the prevalence, impact of CHABs and mitigation efforts were reviewed, focusing on the Lake Erie region and Ohio’s inland lakes that have been impacted heavily as an example so that the findings can be transferrable to other parts of the world that face the similar problems due to the CHABs in their freshwater environments. This paper provides a basic introduction to CHABs and their toxins as well as an overview of public health implications including exposure routes, health effects, and drinking water issues, algal bloom advisory practices in Ohio, toxin measurements results in Ohio public water supplies, and mitigation efforts.

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

Role of Heavy Metal Resistant Ochrobactrum sp. and Bacillus spp. Strains in Bioremediation of a Rice Cultivar and Their PGPR Like Activities: Sanjeev Pandey , Pallab Kumar Ghosh , Sisir Ghosh , Tarun Kumar De , Tushar Kanti Maiti; J. Microbiol. 2013;51(1):11-17. Published online March 2, 2013; DOI: https://doi.org/10.1007/s12275-013-2330-7

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175 Citations

Abstract: The present study demonstrates the metal toxicity ameliorating and growth promoting abilities of three different bacterial isolates when applied to rice as host plant. The three bacterial strains included a cadmium resistant Ochrobactrum sp., a lead resistant Bacillus sp. and an arsenic resistant Bacillus sp. designated as CdSP9, PbSP6, and AsSP9, respectively. When these isolates were used as inocula applied to metaltreated rice plants of variety Satabdi, the germination percentage, relative root elongation (RRE), amylase and protease activities were increased. The toxic effect of metal was reduced in presence of these bacteria. The overall biomass and root/shoot ratio were also enhanced by bacterial inoculation. Hydroponic studies showed that the superoxide dismutase (SOD) activity and malondialdehyde (MDA) level, which had been increased in the presence of metal stress in rice roots, were lowered by the bacterial inoculation. In addition, all three strains were 1-aminocyclopropane-1-carboxylate (ACC) deaminase and catalase positive, whereas siderophore producing ability was lacking in PbSP6. However, both PbSP6 and AsSP9 were protease positive and could hydrolyse starch. The data indicate that these bacteria have promise for bioremediation as well as for plant growth promotion.

Quantification of Toxigenic Microcystis spp. in Freshwaters by Quantitative Real-time PCR Based on the Microcystin Synthetase A Gene: Kyoung-Hee Oh , Dong-Hwan Jeong , Young-Cheol Cho; J. Microbiol. 2013;51(1):18-24. Published online March 2, 2013; DOI: https://doi.org/10.1007/s12275-013-2354-z

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14 Citations

Abstract: A method to estimate the abundance of toxigenic Microcystis in environmental samples by using quantitative real-time PCR was developed and optimized. The basis of this method is the amplification of a highly conserved region of the mcyA gene within the microcystin synthetase gene cluster. Using this method, the average copy number of mcyA gene per cell in toxigenic Microcystis strains was estimated. The molecular markers and method developed in this study can be used to monitor toxigenic strains of Microcystis in Korean freshwaters, in which harmful cyanobacterial blooms are routinely found.

Pedobacter namyangjuensis sp. nov. Isolated from Soil and Reclassification of Nubsella zeaxanthinifaciens Asker et al. 2008 as Pedobacter zeaxanthinifaciens comb. nov.: Dong-Uk Kim , Yoo-Jeong Kim , Dong-Hyeon Shin , Hang-Yeon Weon , Soon-Wo Kwon , Chi-Nam Seong , Jong-Ok Ka; J. Microbiol. 2013;51(1):25-30. Published online March 2, 2013; DOI: https://doi.org/10.1007/s12275-013-2231-9

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15 Citations

Abstract: A Gram-stain-negative, non-motile, strictly aerobic, yellowpigmented bacterium, designated strain 5G38T, was isolated from a field cultivated with Chinese cabbage in Korea. The strain grew at 5–40°C and at pH 6.0–8.0. 16S rRNA gene sequence analysis revealed that strain 5G38T represented a distinct lineage within the family Sphingobacteriaceae and showed the highest 16S rRNA gene sequence similarity of 95.2% with Pedobacter koreensis WPCB189T, followed by Pedobacter agri PB92T (94.6%), Pedobacter suwonensis 15-52T (94.4%), Pedobacter rhizosphaerae 01-96T (94.4%), Pedobacter sandarakinus DS-27T (94.4%), and Nubsella zeaxanthinifaciens TDMA-5T (94.3%). Strain 5G38T formed monophyletic clade with Nubsella zeaxanthinifaciens in the cluster comprised of species of the genus Pedobacter. Chemotaxonomic characteristics of the novel strains, including DNA G+C content of genomic DNA (37.0 mol%), the predominant respiratory quinine (MK-7), and the major fatty acids which were iso-C15:0, summed feature 3 (comprising C16:1ω7c and/or iso-C15:0 2-OH) and iso-C17:0 3-OH, are similar to those of the genus Pedobacter. However, the novel strains can be distinguished from the other species of Pedobacter by physiological properties. The name Pedobacter namyangjuensis sp. nov. is therefore proposed for strain 5G38T (KACC 13938T =NBRC 107692T) as the type strain. Furthermore, the reclassification of Nubsella zeaxanthinifaciens as Pedobacter zeaxanthinifaciens comb. nov. is proposed.

Development of SCAR Primers Based on a Repetitive DNA Fingerprint for Escherichia coli Detection: Aphidech Sangdee , Sitakan Natphosuk , Adunwit Srisathan , Kusavadee Sangdee; J. Microbiol. 2013;51(1):31-35. Published online March 2, 2013; DOI: https://doi.org/10.1007/s12275-013-2244-4

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Abstract: The present study aimed to use enterobacterial repetitive intergenic consensus (ERIC) fingerprints to design SCAR primers for the detection of Escherichia coli. The E. coli strains were isolated from various water sources. The primary presumptive identification of E. coli was achieved using MacConkey agar. Nineteen isolates were selected and confirmed to be E. coli strains based on seven biochemical characteristics. ERIC-PCR with ERIC 1R and ERIC 2 primers were used to generate DNA fingerprints. ERIC-PCR DNA profiles showed variant DNA profiles among the tested E. coli strains and distinguished all E. coli strains from the other tested bacterial strains. A 350 bp band that predominated in five E. coli strains was used for the development of the species-specific SCAR primers EC-F1 and EC-R1. The primers showed good specificity for E. coli, with the exception of a single false positive reaction with Sh. flexneri DMST 4423. The primers were able to detect 50 pg and 100 CFU/ml of genomic DNA and cells of E. coli, respectively.

Bhargavaea indica sp. nov., a Member of the Phylum Firmicutes, Isolated from Arabian Sea Sediment: Pankaj Verma , Chi Nam Seong , Prashant Kumar Pandey , Ramesh Ramchandra Bhonde , Cathrin Spröer , Manfred Rohde , Yogesh Shreepad Shouche; J. Microbiol. 2013;51(1):36-42. Published online March 2, 2013; DOI: https://doi.org/10.1007/s12275-013-2488-z

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6 Citations

Abstract: A Gram-positive, aerobic, coccoid-rod shaped, non-motile, catalase- and oxidase-positive bacterium, designated strain KJW98T, was isolated from the marine sediment of Karwar jetty, west coast of India. The strain was β-haemolytic, nonendospore-forming and grew with 0–8.5% (w/v) NaCl, at 15–48°C and at pH 6.5–9.0, with optimum growth with 0.5% (w/v) NaCl, at 42°C and at pH 7.0–8.0. Phylogenetic analyses based on 16S rRNA and gyrB gene sequences showed that strain KJW98T forms a lineage within the genus Bhargavaea. The G+C content of the genomic DNA was 55 mol%. The DNA–DNA relatedness values of strain KJW98T with B. eijingensis DSM 19037T, B. cecembensis LMG 24411T and B. ginsengi DSM 19038T were 43.2, 39 and 26.5%, respectively. The major fatty acids were anteiso-C15:0 (37.7%), iso-C15:0 (19.7%), anteiso-C17:0 (17.0%) and iso-C16:0 (11.1%). The predominant menaquinone was MK-8 and the cell-wall peptidoglycan was of A4α type with L-lysine as the diagnostic diamino acid. The major polar lipids were diphosphatidylglycerol and phosphatidylglycerol. The phenotypic, genotypic and DNA–DNA relatedness data indicate that strain KJW98T should be distinguished from the members of the genus Bhargavaea, for which the name Bhargavaea indica sp. nov. is proposed with the type strain KJW98T (=KCTC 13583T =LMG 25219T).

Phylogenetic Relationships of Korean Sparassis latifolia Based on Morphological and ITS rDNA Characteristics: Rhim Ryoo , Hong-Duck Sou , Kang-Hyeon Ka , Hyun Park; J. Microbiol. 2013;51(1):43-48. Published online March 2, 2013; DOI: https://doi.org/10.1007/s12275-013-2503-4

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22 Citations

Abstract: Recent studies based on morphological characteristics and molecular analyses have revealed that the characteristics of Sparassis crispa from Asia are not concordant with those of collections from Europe and North America. Consequently, the Asian isolate was redefined as Sparassis latifolia. This study is the first report of Sparassis latifolia collected in Korea. The taxonomic relationships and replacement of Sparassis species were inferred from a comparison of the morphological characteristics and by molecular sequence analysis of the internal transcribed spacer (ITS) rDNA regions. In particular, this study focused on the phylogenetic relationships inferred from the biogeographical distribution of isolates within the genus Sparassis.

Journal Article

Interrelationship of Bradyrhizobium sp. and Plant Growth-Promoting Bacteria in Cowpea: Survival and Symbiotic Performance: Artenisa Cerqueira Rodrigues , Jadson Emanuel Lopes Antunes , Antônio Félix da Costa , José de Paula Oliveira , Marcia do Vale Barreto Figueiredo; J. Microbiol. 2013;51(1):49-55. Published online March 2, 2013; DOI: https://doi.org/10.1007/s12275-013-2335-2

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11 Citations

Abstract: The objective of this study was to evaluate the survival of cowpea during bacterial colonization and evaluate the interrelationship of the Bradyrhizobium sp. and plant growthpromoting bacteria (PGPB) as a potential method for optimizing symbiotic performance and cowpea development. Two experiments using the model legume cowpea cv. “IPA 206” were conducted. In the first experiment, cowpea seeds were disinfected, germinated and transferred to sterilized Gibson tubes containing a nitrogen-free nutritive solution. The experimental design was randomized blocks with 24 treatments [Bradyrhizobium sp. (BR 3267); 22 PGPB; absolute control (AC)] with three replicates. In the second experiment, seeds were disinfected, inoculated according to their specific treatment and grown in Leonard jars containing washed and autoclaved sand. The experimental design was randomized blocks with 24 treatments [BR 3267; 22 BR 3267 + PGPB; AC] with three replicates. Scanning electron microscopy demonstrated satisfactory colonization of the roots of inoculated plants. Additionally, synergism between BR 3267 and PGPB in cowpeas was observed, particularly in the BR 3267 + Paenibacillus graminis (MC 04.21) and BR 3267 + P. durus (C 04.50), which showed greater symbiotic performance and promotion of cowpea development.

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

Novel and Highly Diverse Fungal Endophytes in Soybean Revealed by the Consortium of Two Different Techniques: Tiago de Souza Leite , Andréia Cnossen-Fassoni , Olinto Liparini Pereira , Eduardo Seiti Gomide Mizubuti , Elza Fernandes de Araújo , Marisa Vieira de Queiroz; J. Microbiol. 2013;51(1):56-69. Published online March 2, 2013; DOI: https://doi.org/10.1007/s12275-013-2356-x

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40 Citations

Abstract: Fungal endophytes were isolated from the leaves of soybean cultivars in Brazil using two different isolation techniques – fragment plating and the innovative dilution-to-extinction culturing – to increase the species richness, frequency of isolates and diversity. A total of 241 morphospecies were obtained corresponding to 62 taxa that were identified by analysis of the internal transcribed spacer (ITS) of the ribosomal DNA (rDNA). The Phylum Ascomycota predominated, representing 99% and 95.2% of isolates in the Monsoy and Conquista cultivars, respectively, whereas the Phylum Basidiomycota represented 1% and 4.8% of isolates, respectively. The genera Ampelomyces, Annulohypoxylon, Guignardia, Leptospora, Magnaporthe, Ophiognomonia, Paraconiothyrium, Phaeosphaeriopsis, Rhodotorula, Sporobolomyces, and Xylaria for the first time were isolated from soybean; this suggests that soybean harbours novel and highly diverse fungi. The yeasts genera Rhodotorula and Sporobolomyces (subphylum Pucciniomycotina) represent the Phylum Basidiomycota. The species richness was greater when both isolation techniques were used. The diversity of fungal endophytes was similar in both cultivars when the same isolation technique was used except for Hill’s index, N1. The use of ITS region sequences allowed the isolates to be grouped according to Order, Class and Phylum. Ampelomyces, Chaetomium, and Phoma glomerata are endophytic species that may play potential roles in the biological control of soybean pathogens. This study is one of the first to apply extinction-culturing to isolate fungal endophytes in plant leaves, thus contributing to the development and improvement of this technique for future studies.

Beginning to Understand the Role of Sugar Carriers in Colletotrichum lindemuthianum: the Function of the Gene mfs1: Monalessa Fábia Pereira , Carolina Maria de Araújo dos Santos , Elza Fernandes de Araújo , Marisa Vieira de Queiroz , Denise Mara Soares Bazzolli; J. Microbiol. 2013;51(1):70-81. Published online March 2, 2013; DOI: https://doi.org/10.1007/s12275-013-2393-5

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18 Citations

Abstract: Fungi of the Colletotrichum genus are among the most prominent phytopathogens that cause diseases with a considerable economic impact, such as anthracnose. The hemibiotrophic fungus Colletotrichum lindemuthianum (teleomorph Glomerella cingulata f. sp. phaseoli) is the causal agent of the anthracnose of the common bean; and similarly to other phytopathogens, it uses multiple strategies to gain access to different carbon sources from its host. In this study, we examine mfs1, a newly identified C. lindemuthianum hexose transporter. The mfs1 gene is expressed only during the necrotrophic phase of the fungus’ interaction within the plant and allows it to utilize the available sugars during this phase. The deletion of mfs1 gene resulted in differential growth of the fungus in a medium that contained glucose, mannose or fructose as the only carbon source. This study is the first to describe a hexose transporter in the hemibiotrophic pathogen C. lindemuthianum and to demonstrate the central role of this protein in capturing carbon sources during the necrotrophic development of the plant/pathogen interaction.

Identification of Petriella setifera LH and Characterization of Its Crude Carboxymethyl Cellulase for Application in Denim Biostoning: Xi-Hua Zhao , Wei Wang , Dong-Zhi Wei; J. Microbiol. 2013;51(1):82-87. Published online March 2, 2013; DOI: https://doi.org/10.1007/s12275-013-2370-z

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Abstract: The phylogenetic tree of the partial elongation factor-1 alpha gene fits better than the partial 18S rDNA for generic classification. From the results of the molecular tree and analysis of morphological characters, Petriella setifera LH was identified. It can be induced to produce carboxymethyl cellulase (CMCase). The crude CMCase only shows a 44.1-kDa band by activity staining after SDS-PAGE. It is optimally active at 55°C and pH 6.0, and is stable from pH 5.0–8.0 and at 45°C or below. The crude CMCase, which is not affected by Co2+, is strongly activated in the presence of 10 mM Na+, K+, Ca2+, Mg2+, EDTA, and Mn2+. It is strongly inhibited by 10 mM Fe2+, Pb2+, Al3+, Zn2+, Ag+, Fe3+, and Cu2+. When compared with denim treatment by Novoprime A800 (a commercial neutral cellulase), crude CMCase exhibits a similar fabric weight loss and indigo dye removal. These results indicate that crude CMCase has potential application in denim biostoning.

Clades of γ-Glutamyltransferases (GGTs) in the Ascomycota and Heterologous Expression of Colletotrichum graminicola CgGGT1, a Member of the Pezizomycotina-only GGT Clade: Marco H. Bello , Lynn Epstein; J. Microbiol. 2013;51(1):88-99. Published online March 2, 2013; DOI: https://doi.org/10.1007/s12275-013-2434-0

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8 Citations

Abstract: Gamma-glutamyltransferase (GGT, EC 2.3.2.2) cleaves the γ-glutamyl linkage in glutathione (GSH). Ascomycetes in either the Saccharomycotina or the Taphrinomycotina have one to three GGTs, whereas members of the Pezizomycotina have two to four GGTs. A Bayesian analysis indicates there are three well-supported main clades of GGTs in the Ascomycota. 1) A Saccharomycotina and a Taphrinomycotinaspecific GGT sub-clade form a yeast main clade. This clade has the three relatively well-characterized fungal GGTs: (Saccharomyces cerevisiae CIS2 and Schizosaccharomyces pombe Ggt1 and Ggt2) and most of its members have all 14 of the highly conserved and critical amino acids that are found in GGTs in the other kingdoms. 2) In contrast, a main clade (GGT3) differs in 11 of the 14 highly conserved amino acids that are found in GGTs in the other kingdoms. All of the 44 Pezizomycotina analyzed have either one or two GGT3s. 3) There is a Pezizomycotina-only GGT clade that has two wellsupported sub-clades (GGT1 and GGT2); this clade differs in only two of the 14 highly conserved amino acids found in GGTs in the other kingdoms. Because the Pezizomycotina GGTs differ in apparently critical amino acids from the crosskingdom consensus, a putative GGT from Colletotrichum graminicola, a member of the Pezizomycotina, was cloned and the protein product was expressed as a secreted protein in Pichia pastoris. A GGT enzyme assay of the P. pastoris supernatant showed that the recombinant protein was active, thereby demonstrating that CgGGT1 is a bona fide GGT.

Expression Analysis of LeNHX1 Gene in Mycorrhizal Tomato under Salt Stress: ZhongQun He , Zhi Huang; J. Microbiol. 2013;51(1):100-104. Published online March 2, 2013; DOI: https://doi.org/10.1007/s12275-013-2423-3

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17 Citations

Abstract: The plant growth, stem sap flow, Na+ and Cl- content, and the expression of vacuolar Na+/H+ antiporter gene (LeNHX1) in the leaves and roots of tomato under different NaCl stresses (0.5% and 1%) were studied to analyze the effect of arbuscular mycorrhizal fungi (AMF) on Na+ and Cl- accumulation and ion exchange. The results showed that arbuscular mycorrhizal (AM) plant growth and stem sap flow increased and salt tolerance improved, whereas Na+ and Claccumulated. Na+ significantly decreased, and no significant decline was detected in Cl- content after AMF inoculation compared with the non-AM plants. The LeNHX1 gene expression was induced in the AM and non-AM plants by NaCl stress. However, AMF did not improve the LeNHX1 level, and low expression was observed in the AM tomato. Hence, the mechanism that reduced the Na+ damage to tomato induced by AMF has little relation to LeNHX1, which can export Na+ from the cytosol to the vacuole across the tonoplast.

Hrq1 Functions Independently of Sgs1 to Preserve Genome Integrity in Saccharomyces cerevisiae: Do-Hee Choi , Rina Lee , Sung-Hun Kwon , Sung-Ho Bae; J. Microbiol. 2013;51(1):105-112. Published online March 2, 2013; DOI: https://doi.org/10.1007/s12275-013-3048-2

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20 Citations

Abstract: Maintenance of genome stability in eukaryotes involves a number of conserved proteins, including RecQ helicases, which play multiple roles at various steps in homologous recombination and DNA repair pathways. Sgs1 has been described as the only RecQ helicase in lower eukaryotes. However, recent studies revealed the presence of a second RecQ helicase, Hrq1, which is most homologous to human RECQL4. Here we show that hrq1Δ mutation resulted in increased mitotic recombination and spontaneous mutation in Saccharomyces cerevisiae, and sgs1Δ mutation had additive effects on the phenotypes of hrq1Δ. We also observed that the hrq1Δ mutant was sensitive to 4-nitroquinoline 1-oxide and cisplatin, which was not complemented by overexpression of Sgs1. In addition, the hrq1Δ sgs1Δ double mutant displayed synthetic growth defect as well as a shortened chronological life span compared with the respective single mutants. Analysis of the type of age-dependent Canr mutations revealed that only point mutations were found in hrq1Δ, whereas significant numbers of gross deletion mutations were found in sgs1Δ. Our results suggest that Hrq1 is involved in recombination and DNA repair pathways in S. cerevisiae independent of Sgs1.

Clonal Spread of Carbapenem Resistant Acinetobacter baumannii ST92 in a Chinese Hospital during a 6-Year Period: Lei Huang , Liying Sun , Yan Yan; J. Microbiol. 2013;51(1):113-117. Published online March 2, 2013; DOI: https://doi.org/10.1007/s12275-013-2341-4

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19 Citations

Abstract: The carbapenem resistance rate of Acinetobacter baumannii in our hospital has increased steadily since 2004. The molecular epidemiology of carbapenem resistant A. baumannii (CRAB) clinical isolates was characterized by multilocus sequence typing (MLST) and rep-PCR in parallel, with pandrug susceptible A. baumannii (PSAB) used as control. MLST was performed to determine the sequence types (STs), and eBURST algorithm was used to analyze their relatedness. Carbapenem resistance related genes (oxa-23, oxa-24, oxa-51, oxa-58, imp, vim, and adeB) were screened using Polymerase Chain Reaction (PCR) method. 23 STs were identified in the 65 included isolates, with ST92 being the predominant clone. PSAB clustered into more singletons than CRAB. The positivity of oxa-23 and adeB correlated with high level carbapenem resistance (MICIPM>32 mg/L, MICMEM>32 mg/L) of CRAB ST92 isolates in 2009, which was different from the resistance pattern (MICIPM≤4 mg/L, 8 mg/L ≤MICMEM≤16 mg/L) of CRAB ST92 isolates in 2004. These observations suggest that clonal spread of CRAB ST92 isolates longitudinally is the possible reason for carbapenem resistance rate increase and correlate with high level carbapenem resistance in our hospital.

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