MSK
Search
- Page Path
- HOME > Search
Journal Article
- Those Nematode‑Trapping Fungi That are not Everywhere: Hints Towards Soil Microbial Biogeography
- Wei Deng , Fa Zhang , Davide Fornacca , Xiao-Yan Yang , Wen Xiao
- J. Microbiol. 2023;61(5):511-523. Published online April 6, 2023
- DOI: https://doi.org/10.1007/s12275-023-00043-7
- 21 View
- 0 Download
- 2 Citations
-
Abstract
- The existence of biogeography for microorganisms is a raising topic in ecology and researchers are employing better distinctions between single species, including the most rare ones, to reveal potential hidden patterns. An important volume of evidence supporting heterogeneous distributions for bacteria, archaea and protists is accumulating, and more recently a few efforts have targeted microscopic fungi. We propose an insight into this latter kingdom by looking at a group of soil nematode-trapping fungi whose species are well-known and easily recognizable. We chose a pure culture approach because of its reliable isolation procedures for this specific group. After morphologically and molecularly identifying all species collected from 2250 samples distributed in 228 locations across Yunnan province of China, we analyzed occurrence frequencies and mapped species, genera, and richness. Results showed an apparent cosmopolitan tendency for this group of fungi, including species richness among sites. However, only four species were widespread across the region, while nonrandom heterogeneous distributions were observed for the remaining 40 species, both in terms of statistical distribution of species richness reflected by a significant variance-to-mean ratio, as well as in terms of visually discernible spatial clusters of rare species and genera on the map. Moreover, several species were restricted to only one location, raising the question of whether endemicity exists for this microbial group. Finally, environmental heterogeneity showed a marginal contribution in explaining restricted distributions, suggesting that other factors such as geographical isolation and dispersal capabilities should be explored. These findings contribute to our understanding of the cryptic geographic distribution of microorganisms and encourage further research in this direction.
Research Support, Non-U.S. Gov'ts
- NOTE] Glyoxal Detoxification in Escherichia coli K-12 by NADPH Dependent Aldo-keto Reductases
- Changhan Lee , Insook Kim , Chankyu Park
- J. Microbiol. 2013;51(4):527-530. Published online August 30, 2013
- DOI: https://doi.org/10.1007/s12275-013-3087-8
- 8 View
- 0 Download
- 15 Citations
-
Abstract
- Glyoxal (GO) and methylglyoxal (MG) are reactive carbonyl compounds that are accumulated in vivo through various pathways. They are presumably detoxified through multiple pathways including glutathione (GSH)-dependent/independent glyoxalase systems and NAD(P)H dependent reductases. Previously, we reported an involvement of aldo-ketoreductases (AKRs) in MG detoxification. Here, we investigated the role of various AKRs (YqhE, YafB, YghZ, YeaE, and YajO) in GO metabolism. Enzyme activities of the AKRs to GO were measured, and GO sensitivities of the corresponding mutants were compared. In addition, we examined inductions of the AKR genes by GO. The results indicate that AKRs efficiently detoxify GO, among which YafB, YghZ, and YeaE are major players.
- Screening of Genes Related to Methylglyoxal Susceptibility
- Insook Kim , Joonho Kim , Bumchan Min , Changhan Lee , Chankyu Park
- J. Microbiol. 2007;45(4):339-343.
- DOI: https://doi.org/2563 [pii]
- 13 View
- 0 Download
-
Abstract
- Methylglyoxal (MG) is a reactive metabolite known to accumulate in certain physiological conditions. We attempted to isolate genes associated with this metabolite by genome-wide mutagenesis with TnphoA derivative. After screening on methylglyoxal-containing plate, we obtained insertions in three different genes, ydbD, yjjQ, and yqiI, which gave rise to reproducible MG-sensitive phenotypes in glyoxalase-deficient strain. In addition to its MG sensitivity, the insertion in yqiI exhibited an impaired motility resulting from a reduced flagellar expression.
- Inhibition of purine nucleoside phosphorylase (PNP) in micrococcus luteus phenylglyoxal
- Choi , Hye Seon
- J. Microbiol. 1996;34(3):270-273.
- 14 View
- 0 Download
-
Abstract
- Micrococcus luteus purine nucleoside phosphorylase (PNP) has been purified and characterized. The physical and kinetic properties have been described previously. Chemical modification of the enzyme was attempted to gain insight on the active site. The enzyme was inactivated in a time-dependent manner by the arginine- specific modifying reagent phenylglyoxal. There was a linear relationship between the observed rate of inactivation and the phenylglyoxal concentration. At 30℃ the bimolecular rate constant for the modification was 0.015 min^-1 mM^-1 in 50 mM NaHCO₃buffer, pH 7.5. The plot of logk versus log phenylglyoxal concentration was a strainght line with a slope enzyme. Preincuation with saturated solutions of substrates protected the enzyme from inhibition of phenylglyoxal, indicating that reactions with phenylglyoxal were directed at arginyl residues essential for the catalytic functioning of the enzyme.
- Chemical Midification of Purin Nucleoside Phosphorulase in Serratia marcescens
- Choi , Hye Seon
- J. Microbiol. 1998;36(2):74-79.
- 15 View
- 0 Download
-
Abstract
- Serratia marcescens purine nucleoside phosphorylase (PNP) has been purified and characterized. The physical and kinetic properties have been previously described(Choi, H.S. 1998. Biosci. Biotechnol. Biochem. 62, 667-671). Chemical modification of the enzyme was attempted to gain insight on the active site. The enzyme was inactivated in a time dependent manner by phenylglyoxal or diethylpyrocarbonate (DEPC). There was a linear relationship between the observed rate of inactivation and the phenylglyoxal or DEPC concentration. At 30℃ the bimolecular rate constant for the modification was 0.22 mM^-1 min^-1 in 50 mM NaHCO_3 buffer, pH 7.5, for phenylglyoxal and 1.33 mM^-1min^-1 in 50 mM sodium cotrate, pH 6.0, for DEPC. Preincubation with saturated solutions of substrates protected the enzyme from inhibition by kphenylglyoxal and DEPC, indicating that reactions with these reagents were directed at arginyl and histidyl residues, respectively, which are essential for the catalytic function of the enzyme.
First
Prev
TOP
