The Journal of General and Applied Microbiology (J GEN APPL MICROBIOL)

Publisher: Tōkyō Daigaku. Ōyō Biseibutsu Kenkyūjo

Journal description

The Journal of General and Applied Microbiology is issued bimonthly, one volume a year, by The Microbiology Research Foundation. The journal is devoted to the publication of original papers pertaining to general and applied microbiology.

Current impact factor: 0.94

Impact Factor Rankings

2016 Impact Factor Available summer 2017
2014 / 2015 Impact Factor 0.943
2013 Impact Factor 0.598
2012 Impact Factor 0.743
2011 Impact Factor 0.984
2010 Impact Factor 1
2009 Impact Factor 0.957
2008 Impact Factor 0.846
2007 Impact Factor 0.925
2006 Impact Factor 0.766
2005 Impact Factor 0.909
2004 Impact Factor 0.655
2003 Impact Factor 0.75
2002 Impact Factor 0.826
2001 Impact Factor 0.512
2000 Impact Factor 0.573
1999 Impact Factor 0.613
1998 Impact Factor 0.609
1997 Impact Factor 0.634
1996 Impact Factor 0.626
1995 Impact Factor 0.593
1994 Impact Factor 0.517
1993 Impact Factor 0.492
1992 Impact Factor 0.476

Impact factor over time

Impact factor
Year

Additional details

5-year impact 1.07
Cited half-life >10.0
Immediacy index 0.05
Eigenfactor 0.00
Article influence 0.33
Website Journal of General and Applied Microbiology website
Other titles Journal of general and applied microbiology
ISSN 0022-1260
OCLC 1782890
Material type Periodical, Internet resource
Document type Journal / Magazine / Newspaper, Internet Resource

Publications in this journal

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    ABSTRACT: Two-component signal transduction systems (TCSs) represent one of the primary means by which bacteria sense and respond to changes in their environment, both intra- and extracellular. The highly conserved WalK (histidine kinase)/WalR (response regulator) TCS is essential for cell wall metabolism of low G+C Gram-positive bacteria and acts as a master regulatory system in controlling and coordinating cell wall metabolism with cell division. Waldiomycin, a WalK inhibitor, has been discovered by screening metabolites from actinomycetes and belongs to the family of angucycline antibiotics. In the present study, we have shown that waldiomycin inhibited autophosphorylation of WalK histidine kinases in vitro from Bacillus subtilis, Staphylococcus aureus, Enterococcus faecalis, and Streptococcus mutans at half-maximal inhibitory concentrations of 10.2, 8.8, 9.2, and 25.8 μM, respectively. Quantitative RT-PCR studies of WalR regulon genes have suggested that waldiomycin repressed the WalK/WalR system in B. subtilis and S. aureus cells. Morphology of waldiomycin-treated S. aureus cells displayed increased aggregation instead of proper cellular dissemination. Furthermore, autolysis profiles of S. aureus cells revealed that waldiomycin-treated cells were highly resistant to Triton X-100- and lysostaphin-induced lysis. These phenotypes are consistent with those of cells starved for the WalK/WalR system, indicating that waldiomycin inhibited the autophosphorylation activity of WalK in cells. We have also confirmed that waldiomycin inhibits WalK autophosphorylation in vivo by actually observing the phosphorylated WalK ratio in cells using Phos-tag SDS-PAGE. The results of our current study strongly suggest that waldiomycin targets WalK histidine kinases and inhibits the WalR regulon genes expression, thereby affecting both cell wall metabolism and cell division.
    Preview · Article · Nov 2015 · The Journal of General and Applied Microbiology
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    ABSTRACT: Bacterial strains capable of utilizing glyphosate as the sole carbon source were isolated from contaminated soil by the enrichment culture method and identified based on partial 16S rRNA gene sequence analysis. Pseudomonas spp. strains GA07, GA09 and GC04 demonstrated the best degradation capabilities towards glyphosate and were used for the laboratory experiments of glyphosate bioremediation. Inoculating glyphosate-treated soil samples with these three strains resulted in a 2-3 times higher rate of glyphosate removal than that in non-inoculated soil. The degradation kinetics was found to follow a first-order model with regression values greater than 0.96. Cell numbers of the introduced bacteria decreased from 4.4 × 10(6) CFU/g to 3.4-6.7 × 10(5) CFU/g dry soil within 18 days of inoculation. Due to the intense degradation of glyphosate, the total dehydrogenase activity of the soil microbial community increased by 21.2-25.6%. Analysis of glyphosate degradation products in cell-free extracts showed that glyphosate breakdown in strain GA09 was catalyzed both by C-P lyase and glyphosate oxidoreductase. Strains GA07 and GC04 degraded glyphosate only via glyphosate oxidoreductase, but no further metabolite was detected. These results highlight the potential of the isolated bacteria to be used in the bioremediation of GP-contaminated soils.
    Preview · Article · Nov 2015 · The Journal of General and Applied Microbiology
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    ABSTRACT: The pollution of land and water by petroleum compounds is a matter of growing concern necessitating the development of methodologies, including microbial biodegradation, to minimize the impending impacts. It has been extensively reported that fungi from polluted habitats have the potential to degrade pollutants, including petroleum compounds. The Red Sea is used extensively for the transport of oil and is substantially polluted, due to leaks, spills, and occasional accidents. Tidal water, floating debris, and soil sediment were collected from mangrove stands on three polluted sites along the Red Sea coast of Saudi Arabia and forty-five fungal isolates belonging to 13 genera were recovered from these samples. The isolates were identified on the basis of a sequence analysis of the 18S rRNA gene fragment. Nine of these isolates were found to be able to grow in association with engine oil, as the sole carbon source, under in vitro conditions. These selected isolates and their consortium accumulated greater biomass, liberated more CO2, and produced higher levels of extracellular enzymes, during cultivation with engine oil as compared with the controls. These observations were authenticated by gas chromatography-mass spectrophotometry (GC-MS) analysis, which indicated that many high mass compounds present in the oil before treatment either disappeared or showed diminished levels.
    No preview · Article · Oct 2015 · The Journal of General and Applied Microbiology
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    Preview · Article · Jan 2015 · The Journal of General and Applied Microbiology
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    ABSTRACT: We generated spheroplasts from Escherichia coli carrying a broad-host-range plasmid. In the presence of penicillin, the spheroplasts did not divide but grew and enlarged in marine broth, whereas, in the absence of penicillin, they elongated. We quantified cellular DNA at different time points by using real-time quantitative PCR. Both chromosomal and plasmid DNA had replicated during spheroplast growth not only in the absence but also in the presence of penicillin. Thus, plasmid DNA and chromosomal DNA replication might be regulated synchronously during the growth of spheroplasts.
    Preview · Article · Jan 2015 · The Journal of General and Applied Microbiology
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    ABSTRACT: Nitro group-containing natural products are rare in nature. There are few examples of N-oxygenases, enzymes that incorporate atmospheric oxygen into primary and secondary amines, characterized in the literature. N-oxygenases have yet to be characterized from the Corynebacterineae, a metabolically diverse group of organisms that includes the genera Rhodococcus, Gordonia, and Mycobacterium. A preliminary in silico search for N-oxygenase AurF gene orthologs revealed multiple protein candidates present in the genome of the Actinomycete Rhodococcus jostii RHAI (RHAI_ro06104). Towards the goal of identifying novel biocatalysts with potential utility for the biosynthesis of nitroaromatics, AurF ortholog RHAI_ro6104 was cloned, expressed and purified in E. coli and amine and nitro containing phenol substrates tested for activity. RHAI-ro06104 showed the highest activity with 4-aminophenol, producing a Vmax of 18.76 μM s–1 and a Km of 15.29 mM and demonstrated significant activities with 2-aminophenol and 2-amino-5-methylphenol, producing a Vmax of 12.86 and 12.72 μM s–1 with a Km of 8.34 and 2.81 mM, respectively. These findings are consistent with a substrate range observed in other N-oxygenases, which seem to accommodate substrates that lack halogenated substitutions and side groups directly flanking the amine group. Attempts to identify modulators of RHAI-ro06104 gene activity demonstrated that aromatic amino acids inhibit expression by almost 50%.
    Preview · Article · Jan 2015 · The Journal of General and Applied Microbiology
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    ABSTRACT: The lipopolysaccharide (LPS) of Azorhizobium caulinodans ORS571, which forms N2-fixing nodules on the stems and roots of Sesbania rostrata, is known to be a positive signal required for the progression of nodule formation. In this study, four A. caulinodans mutants producing a variety of defective LPSs were compared. The LPSs of the mutants having Tn5 insertion in the rfaF, rfaD, and rfaE genes were more truncated than the modified LPSs of the oac2 mutants. However, the nodule formation by the rfaF, rfaD, and rfaE mutants was more advanced than that of the oac2 mutant, suggesting that invasion ability depends on the LPS structure. Our hypothesis is that not only the wild-type LPSs but also the altered LPSs of the oac2 mutant may be recognized as signal molecules by plants. The altered LPSs may act as negative signals that halt the symbiotic process, whereas the wild-type LPSs may prevent the halt of the symbiotic process. The more truncated LPSs of the rfaF, rfaD, and rfaE mutants perhaps no longer function as negative signals inducing discontinuation of the symbiotic process, and thus these strains form more advanced nodules than ORS571-oac2.
    Preview · Article · Jan 2015 · The Journal of General and Applied Microbiology
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    ABSTRACT: Chitinase B from Serratia marcescens 2170 is one of the processive chitinases, and it has a linear path of aromatic amino acid residues on the surface and in the catalytic cleft. There are four surface-exposed residues lined-up towards the cleft, Y481, W479, W252, and Y240. The substitution of these residues with alanine causes a decrease in both the extent of the substrate binding and the hydrolytic activity (Katouno et al., 2004). Here, we examine the three mutants without losing the substrate-binding ability, Y240W, Y481W, and Y240W/Y481W. These mutants were prepared for a detailed analysis of the functions of Y240 and Y481, which showed a lower contribution to substrate binding than W479 and W252. The parameters for the binding of the three mutants to crystalline β-chitin were similar to those for the wild type. The hydrolytic activity of Y240W and Y240W/Y481W against crystalline β-chitin was significantly decreased. However, the hydrolytic activity of Y481W was similar to that of the wild type, indicating some differences in the roles of Y240 and Y481 during the processive degradation of crystalline β-chitin. Taken together with the previous results, it was suggested that while Y240 and Y481 were required for the substrate binding, Y240 had additional roles in the processive degradation of crystalline β-chitin, possibly in guiding a chitin chain into the catalytic cleft.
    No preview · Article · Jan 2015 · The Journal of General and Applied Microbiology
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    ABSTRACT: A newly isolated strain, CWD-67, which exhibited high fibrinolytic activity, was screened from dumping soils enriched with poultry wastes. The strain was identified as Bacillus tequilensis (KF897935) by 16Sr RNA gene sequence analysis and biochemical characterization. A fibrinolytic enzyme was purified to homogeneity from the culture supernatant using ammonium sulfate precipitation, membrane concentration, dialysis, ion-exchange, and gel filtration chromatography. SDS-PAGE analysis showed that the purified enzyme was a monomeric protein with an apparent molecular weight of 22 kDa, which is the lowest among Bacillus fibrinolytic enzymes reported to date. The purified enzyme was confirmed to have fibrinolytic activity by a fibrin zymogram. The optimal pH and temperature values of the enzyme were 8.0 and 45°C, respectively. The enzyme was completely inhibited by PMSF and significantly inhibited by EDTA, TPCK, Co2+, Zn2+, and Cu2+, suggesting a chymotrypsin-like serine metalloprotease. In vitro assays revealed that the purified enzyme could catalyze fibrin lysis effectively, indicating that this enzyme could be a useful fibrinolytic agent.
    Preview · Article · Jan 2015 · The Journal of General and Applied Microbiology
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    ABSTRACT: In this study, genetically engineered Pseudomonas putida TODE1 served as a biocatalyst for the bioproduction of valuable 3-methylcatechol (3MC) from toluene in an aqueous-organic two-phase system. The two-phase system was used as an approach to increase the biocatalyst efficiency. Among the organic solvent tested, n-decanol offered several benefits including having the highest partitioning of 3MC, with a high 3MC yield and low cell toxicity. The effect of media supplementation with carbon/energy sources (glucose, glycerol, acetate and succinate), divalent metal cations (Mg(2+), Ca(2+), Mn(2+) and Fe(2+)), and short-chain alcohols (ethanol, n-propanol and n-butanol) as a cofactor regeneration system on the toluene dioxygenase (TDO) activity, cell viability, and overall 3MC yield were evaluated. Along with the two-step cell preparation protocol, supplementation of the medium with 4 mM glycerol as a carbon/energy source, and 0.4 mM Fe(2+) as a cofactor for TDO significantly enhanced the 3MC production level. When in combination with the use of n-decanol and n-butanol as the organic phase, a maximum overall 3MC concentration of 31.8 mM (166 mM in the organic phase) was obtained in a small-scale production, while it was at 160.5 mM (333.2 mM in the organic phase) in a 2-L scale. To our knowledge, this is the highest 3MC yield obtained from a TDO-based system so far.
    No preview · Article · Nov 2014 · The Journal of General and Applied Microbiology
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    ABSTRACT: Direct ethanol fermentation from amorphous cellulose was achieved using an engineered industrial Saccharomyces cerevisiae strain. Two cellulase genes endoglucanase (eg3) and β-glucosidase (bgl1) were obtained from Trichoderma viride and integrated into the genome of S. cerevisiae. These two cellulases could be constitutively coexpressed and secreted by the recombinant strain S. cerevisiae-eb. The enzyme activities were analyzed in the culture supernatants, with the highest endoglucanase activity of 2.34 units/ml and β-glucosidase activity of 0.95 units/ml. The effects of pH, temperature and metal ions on enzyme activities were analyzed. The coexpression strain S. cerevisiae-eb could grow in carboxymethyl cellulose (CMC) and utilize it as the single carbon source. The 20 g/L CMC as a model substrate of amorphous cellulose was used in fermentation. The ethanol production reached 4.63 g/L in 24 h, with the conversion ratio of 64.2% compared with the theoretical concentration. This study demonstrated that the engineered industrial strain S. cerevisiae-eb could convert amorphous cellulose to ethanol simultaneously and achieve consolidated bioprocessing (CBP) directly.
    No preview · Article · Nov 2014 · The Journal of General and Applied Microbiology
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    ABSTRACT: Bacillus subtilis is used industrially for the production of secreted enzymes. The most characteristic feature of the secreted enzymes is variation in the N-terminal signal peptides that is recognized by secretion machinery, which is one of the determinants of efficiency and must be customized in each case. Culturing cellulolytic B. subtilis to secrete heterologous cellulases combined with customized signal peptides would be beneficial for producing biocommodities from cellulosic biomass. Four Clostridium thermocellum genes, encoding endoglucanases (celA and celB) and exoglucanases (celK and celS) were cloned to construct random libraries of combinations with 173 different signal peptides originating from the B. subtilis genome. The libraries were successfully screened to identify the signal peptides most efficient in secretion of each of the four cellulases, which were theoretically unpredictable. The secreted cellulases were assayed on carboxymethyl cellulose, phosphoric acid swollen cellulose, and microcrystalline cellulose to determine the possible effects of the signal peptides on substrate specificity. The customized signal peptides for CelA, CelB, and CelS did not affect enzyme performance but those for CelK might influence its substrate specificity.
    No preview · Article · Nov 2014 · The Journal of General and Applied Microbiology
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    ABSTRACT: Brine shrimp are aquatic crustaceans belonging to a genus of Artemia. This organism is widely used for testing the toxicity of chemicals. In this study, brine shrimp were evaluated as an infection model organism to study bacterial virulence. Artemia nauplii were infected with various pathogenic bacteria, such as Vibrio vulnificus, Pseudomonas aeruginosa, Burkholderia vietnamiensis, Staphylococcus aureus, and Escherichia coli, and the susceptibility to these bacteria was investigated by counting the survival of the infected nauplii. While all of the tested bacteria have significant virulence to brine shrimp, killing the nauplii in a few days, V. vulnificus showed the strongest virulence. P. aeruginosa also showed a dose-dependent virulence to brine shrimp, but the virulence was weaker than that of V. vulnificus. The virulence tests using the virulence-attenuated mutants of V. vulnificus and P. aeruginosa, such as quorum sensing (QS) mutants or protease-deficient mutants showed a significant attenuation of virulence, demonstrating that the QS mechanism is important in the virulence of these bacteria to brine shrimp. B. vietnamiensis, S. aureus, and E. coli were also virulent to brine shrimp and the virulence was correlated with dosage within 24 h under our conditions. Salmonella enterica Typhimurium and Bacillus subtilis were also virulent to brine shrimp, but the virulence was weak and slowly exerted compared with that of other bacteria. Taken together, we suggest that brine shrimp are a good infection model to assay bacterial virulence, especially for V. vulnificus and P. aeruginosa, and QS is important in the bacterial virulence to brine shrimp.
    No preview · Article · Nov 2014 · The Journal of General and Applied Microbiology
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    ABSTRACT: An Escherichia coli system was engineered for the heterologous production of itaconic acid via the expression of cis-aconitate decarboxylase gene (cad), and then maximal itaconic acid levels produced by engineered E. coli were evaluated. Expression of cad in E. coli grown in Luria-Bertani (LB) medium without glucose in a test tube resulted in 0.07 g/L itaconic acid production after 78 h at 20°C. To increase itaconic acid production, E. coli recombinants were constructed by inactivating the isocitrate dehydrogenase gene (icd) and/or the isocitrate lyase gene (aceA). Expression of cad and inactivation of icd resulted in 0.35 g/L itaconic acid production after 78 h, whereas aceA inactivation had no effect on itaconic acid production. The intracellular itaconate concentration in the Δicd strain was higher than that in the cad-expressing strain without icd inactivation, which suggests that the extracellular secretion of itaconate in E. coli is the rate-determining step during itaconic acid production. pH-stat cultivation using the cad-expressing Δicd strain in LB medium with 3% glucose in a jar fermenter resulted in 1.71 g/L itaconic acid production after 97 h at 28°C. To further increase itaconic acid production, the aconitase B gene (acnB) was overexpressed in the cad-expressing Δicd strain. Simultaneous overexpression of acnB with the expression of cad in the Δicd strain led to 4.34 g/L itaconic acid production after 105 h. Our findings indicate that icd inactivation and acnB overexpression considerably enhance itaconic acid production in cad-expressing E. coli.
    No preview · Article · Nov 2014 · The Journal of General and Applied Microbiology
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    ABSTRACT: The intracellular trehalose levels in Shirakami kodama yeast, a strain of Saccharomyces cerevisiae, isolated in 1997 from leaf mold in the Shirakami Mountains and since used as a commercial baker's yeast, are remarkably high, which presumably is related to its tolerance of freezing and drought conditions. We isolated a spore clone from Shirakami kodama yeast with about 1.7-fold higher intracellular trehalose levels than the parental strain and set out to elucidate how this spore clone can accumulate intracellular trehalose to such a high concentration. The gene for trehalose 6-phosphate synthase, TPS1, was duplicated in this spore clone. Both TPS1 genes contributed to the high level of intracellular trehalose as a 3.4-fold decrease resulted from the disruption of one of the two TPS1 genes. Both Msn2 and Msn4, which bind to stress responsive elements in the promoter region of TPS1, were required for production of high levels of trehalose. Furthermore, the neutral trehalase activity of this spore clone is about 3-fold less than that of the laboratory strain although the gene for neutral trehalase, NTH1, functioned normally. These findings indicate that two TPS1 genes and the low trehalase activity are associated with high trehalose accumulation in this spore clone. The wide range of stresses of which we found the spore clone to be tolerant makes this yeast very attractive for commercial application and for further research into the mechanisms underlying stress responses and trehalose metabolism.
    No preview · Article · Oct 2014 · The Journal of General and Applied Microbiology

  • No preview · Article · Oct 2014 · The Journal of General and Applied Microbiology