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- Tubulysin Production by the Dead Cells of Archangium gephyra KYC5002.
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Seohui Park, Chaehyeon Park, Yujin Ka, Kyungyun Cho
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J. Microbiol. 2024;62(6):463-471. Published online June 13, 2024
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DOI: https://doi.org/10.1007/s12275-024-00130-3
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Abstract
- Archangium gephyra KYC5002 produces tubulysins during the death phase. In this study, we aimed to determine whether dead cells produce tubulysins. Cells were cultured for three days until the verge of the death phase, disrupted via ultrasonication, incubated for 2 h, and examined for tubulysin production.
Non-disrupted cells produced 0.14 mg/L of tubulysin A and 0.11 mg/L of tubulysin B. Notably, tubulysin A production was increased by 4.4-fold to 0.62 mg/L and that of tubulysin B was increased by 6.7-fold to 0.74 mg/L in the disrupted cells. The same increase in tubulysin production was observed when the cells were killed by adding hydrogen peroxide. However, when the enzymes were inactivated via heat treatment of the cultures at 65 °C for 30 min, no significant increase in tubulysin production due to cell death was observed. Reverse transcription-quantitative polymerase chain reaction analysis of tubB mRNA revealed that the expression levels of tubulysin biosynthetic enzyme genes increased during the death phase compared to those during the vegetative growth phase. Our findings suggest that A. gephyra produces biosynthetic enzymes and subsequently uses them for tubulysin production in the cell death phase or during cell lysis by predators.
- Tn5 Transposon-based Mutagenesis for Engineering Phage-resistant Strains of Escherichia coli BL21 (DE3)
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Yinfeng Wang , Guanhua Xuan , Houqi Ning , Jiuna Kong , Hong Lin , Jingxue Wang
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J. Microbiol. 2023;61(5):559-569. Published online May 22, 2023
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DOI: https://doi.org/10.1007/s12275-023-00048-2
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Abstract
- Escherichia coli is a preferred strain for recombinant protein production, however, it is often plagued by phage infection
during experimental studies and industrial fermentation. While the existing methods of obtaining phage-resistant strains
by natural mutation are not efficient enough and time-consuming. Herein, a high-throughput method by combining Tn5
transposon mutation and phage screening was used to produce Escherichia coli BL21 (DE3) phage-resistant strains. Mutant
strains PR281-7, PR338-8, PR339-3, PR340-8, and PR347-9 were obtained, and they could effectively resist phage infection.
Meanwhile, they had good growth ability, did not contain pseudolysogenic strains, and were controllable. The resultant
phage-resistant strains maintained the capabilities of producing recombinant proteins since no difference in mCherry red
fluorescent protein expression was found in phage-resistant strains. Comparative genomics showed that PR281-7, PR338-8,
PR339-3, and PR340-8 mutated in ecpE, nohD, nrdR, and livM genes, respectively. In this work, a strategy was successfully
developed to obtain phage-resistant strains with excellent protein expression characteristics by Tn5 transposon mutation.
This study provides a new reference to solve the phage contamination problem.
- CXCL12/CXCR4 Axis is Involved in the Recruitment of NK Cells by HMGB1 Contributing to Persistent Airway Inflammation and AHR During the Late Stage of RSV Infection
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Sisi Chen , Wei Tang , Guangyuan Yu , Zhengzhen Tang , Enmei Liu
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J. Microbiol. 2023;61(4):461-469. Published online February 13, 2023
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DOI: https://doi.org/10.1007/s12275-023-00018-8
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Abstract
- We previously showed that both high-mobility group box-1 (HMGB1) and natural killer (NK) cells contribute to respiratory
syncytial virus (RSV)-induced persistent airway inflammation and airway hyperresponsiveness (AHR). Meanwhile,
Chemokine (C-X-C motif) ligand 12 (CXCL12) and its specific receptor (chemokine receptor 4, CXCR4) play important
roles in recruitment of immune cells. CXCL12 has been reported to form a complex with HMGB1 that binds to CXCR4 and
increases inflammatory cell migration. The relationship between HMGB1, NK cells and chemokines in RSV-infected model
remains unclear. An anti-HMGB1 neutralizing antibody and inhibitor of CXCR4 (AMD3100) was administered to observe
changes of NK cells and airway disorders in nude mice and BALB/c mice. Results showed that the mRNA expression and
protein levels of HMGB1 were elevated in late stage of RSV infection and persistent airway inflammation and AHR were
diminished after administration of anti-HMGB1 antibodies, with an associated significant decrease in CXCR4+
NK cells. In
addition, CXCL12 and CXCR4 were reduced after HMGB1 blockade. Treatment with AMD3100 significantly suppressed
the recruitment of NK cells and alleviated the airway disorders. Thus, CXCL12/CXCR4 axis is involved in the recruitment
of NK cells by HMGB1, contributing to persistent airway inflammation and AHR during the late stage of RSV infection.
- Phenotypic and genomic characteristics of Brevibacterium zhoupengii sp. nov., a novel halotolerant actinomycete isolated from bat feces
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Yuyuan Huang , Lingzhi Dong , Jian Gong , Jing Yang , Shan Lu , Xin-He Lai , Dong Jin , Qianni Huang , Ji Pu , Liyun Liu , Jianguo Xu
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J. Microbiol. 2022;60(10):977-985. Published online August 19, 2022
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DOI: https://doi.org/10.1007/s12275-022-2134-8
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Abstract
- Two strictly aerobic, Gram-staining-positive, non-spore-forming,
regular rod-shaped (approximately 0.7 × 1.9 mm)
bacteria (HY170T and HY001) were isolated from bat feces
collected from Chongzuo city, Guangxi province (22°2054N,
106°4920E, July 2011) and Chuxiong Yi Autonomous Prefecture,
Yunnan province (25°0910N, 102°0439E, October
2013) of South China, respectively. Optimal growth is obtained
at 25–28°C (range, 4–32°C) on BHI-5% sheep blood
plate with pH 7.5 (range, 5.0–10.0) in the presence of 0.5–
1.0% NaCl (w/v) (range, 0–15% NaCl [w/v]). The phylogenetic
and phylogenomic trees based respectively on the 16S
rRNA gene and 845 core gene sequences revealed that the
two strains formed a distinct lineage within the genus Brevibacterium,
most closely related to B. aurantiacum NCDO
739T (16S rRNA similarity, both 98.5%; dDDH, 46.7–46.8%;
ANI, 91.9–92.1%). Strain HY170T contained MK-8(H2), diphosphatidylglycerol
(DPG) and phosphatidylglycerol (PG),
galactose and ribose as the predominant menaquinone, major
polar lipids, and main sugars in the cell wall teichoic acids,
respectively. The meso-diaminopimelic acid (meso-DAP)
was the diagnostic diamino acid of the peptidoglycan found
in strain HY170T. Anteiso-C15:0 and anteiso-C17:0 were the
major fatty acids (> 10%) of strains HY170T and HY001, with
anteiso-C17:1A predominant in strain HY170T but absent in
strain HY001. Mining the genomes revealed the presence
of secondary metabolite biosynthesis gene clusters encoding
for non-alpha poly-amino acids (NAPAA), ectoine, siderophore,
and terpene. Based on results from the phylogenetic,
chemotaxonomic and phenotypic analyses, the two strains
could be classified as a novel species of the genus Brevibacterium,
for which the name Brevibacterium zhoupengii sp.
nov. is proposed (type strain HY170T = CGMCC 1.18600T
= JCM 34230T).
- Characterization of a cold-adapted debranching enzyme and its role in glycogen metabolism and virulence of Vibrio vulnificus MO6-24/O
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Ah-Reum Han , Haeyoung Kim , Jong-Tae Park , Jung-Wan Kim
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J. Microbiol. 2022;60(4):375-386. Published online February 14, 2022
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DOI: https://doi.org/10.1007/s12275-022-1507-3
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Abstract
- Vibrio vulnificus MO6-24/O has three genes annotated as
debranching enzymes or pullulanase genes. Among them,
the gene encoded by VVMO6_03032 (vvde1) shares a higher
similarity at the amino acid sequence level to the glycogen
debranching enzymes, AmyX of Bacillus subtilis (40.5%) and
GlgX of Escherichia coli (55.5%), than those encoded by the
other two genes. The vvde1 gene encoded a protein with a molecular
mass of 75.56 kDa and purified Vvde1 efficiently hydrolyzed
glycogen and pullulan to shorter chains of maltodextrin
and maltotriose (G3), respectively. However, it hydrolyzed
amylopectin and soluble starch far less efficiently,
and β-cyclodextrin (β-CD) only rarely. The optimal pH and
temperature of Vvde1 was 6.5 and 25°C, respectively. Vvde1
was a cold-adapted debranching enzyme with more than 60%
residual activity at 5°C. It could maintain stability for 2 days
at 25°C and 1 day at 35°C, but it destabilized drastically at
40°C. The Vvde1 activity was inhibited considerably by Cu2+,
Hg2+, and Zn2+, while it was slightly enhanced by Co2+, Ca2+,
Ni2+, and Fe2+. The vvde1 knock-out mutant accumulated more
glycogen than the wild-type in media supplemented with 1.0%
maltodextrin; however, the side chain length distribution of
glycogen was similar to that of the wild-type except G3, which
was much more abundant in the mutant. Therefore, Vvde1
seemed to debranch glycogen with the degree of polymerization
3 (DP3) as the specific target branch length. Virulence
of the pathogen against Caenorhabditis elegans was attenuated
significantly by the vvde1 mutation. These results suggest
that Vvde1 might be a unique glycogen debranching enzyme
that is involved in both glycogen utilization and shaping of
glycogen molecules, and contributes toward virulence of the
pathogen.
- Potent antibacterial and antibiofilm activities of TICbf-14, a peptide with increased stability against trypsin
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Liping Wang , Xiaoyun Liu , Xinyue Ye , Chenyu Zhou , Wenxuan Zhao , Changlin Zhou , Lingman Ma
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J. Microbiol. 2022;60(1):89-99. Published online December 29, 2021
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DOI: https://doi.org/10.1007/s12275-022-1368-9
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Abstract
- The poor stability of peptides against trypsin largely limits
their development as potential antibacterial agents. Here, to
obtain a peptide with increased trypsin stability and potent
antibacterial activity, TICbf-14 derived from the cationic peptide
Cbf-14 was designed by the addition of disulfide-bridged
hendecapeptide (CWTKSIPPKPC) loop. Subsequently, the
trypsin stability and antimicrobial and antibiofilm activities
of this peptide were evaluated. The possible mechanisms underlying
its mode of action were also clarified. The results
showed that TICbf-14 exhibited elevated trypsin inhibitory
activity and effectively mitigated lung histopathological damage
in bacteria-infected mice by reducing the bacterial counts,
further inhibiting the systemic dissemination of bacteria and
host inflammation. Additionally, TICbf-14 significantly repressed
bacterial swimming motility and notably inhibited
biofilm formation. Considering the mode of action, we observed
that TICbf-14 exhibited a potent membrane-disruptive
mechanism, which was attributable to its destructive effect
on ionic bridges between divalent cations and LPS of the bacterial
membrane. Overall, TICbf-14, a bifunctional peptide
with both antimicrobial and trypsin inhibitory activity, is
highly likely to become an ideal candidate for drug development
against bacteria.
- Brevibacterium limosum sp. nov., Brevibacterium pigmenatum sp. nov., and Brevibacterium atlanticum sp. nov., three novel dye decolorizing actinobacteria isolated from ocean sediments
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Shengxiang Pei , Siwen Niu , Fuquan Xie , Wenjing Wang , Shuang Zhang , Gaiyun Zhang
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J. Microbiol. 2021;59(10):898-910. Published online September 7, 2021
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DOI: https://doi.org/10.1007/s12275-021-1235-0
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Abstract
- During a study of the marine actinobacterial biodiversity, a
large number of Brevibacterium strains were isolated. Of these,
five that have relatively low 16S rRNA gene similarity (98.5–
99.3%) with validly published Brevibacterium species, were
chosen to determine taxonomic positions. On the basis of 16S
rRNA gene sequence analysis and BOX-PCR fingerprinting,
strains o2T, YB235T, and WO024T were selected as representative
strains. Genomic analyses, including average nucleotide
identity (ANI) and digital DNA-DNA hybridization (dDDH),
clearly differentiated the three strains from each other and
from their closest relatives, with values ranging from 82.8%
to 91.5% for ANI and from 26.7% to 46.5% for dDDH that
below the threshold for species delineation. Strains YB235T,
WO024T, and o2T all exhibited strong and efficient decolorization
activity in congo red (CR) dyes, moderate decolorization
activity in toluidine blue (TB) dyes and poor decolorization
in reactive blue (RB) dyes. Genes coding for peroxidases
and laccases were identified and accounted for these strains’
ability to effectively oxidize a variety of dyes with different
chemical structures. Mining of the whole genome for secondary
metabolite biosynthesis gene clusters revealed the presence
of gene clusters encoding for bacteriocin, ectoine, NRPS,
siderophore, T3PKS, terpene, and thiopeptide. Based on the
phylogenetic, genotypic and phenotypic data, strains o2T,
YB235T and WO024T clearly represent three novel taxa within
the genus Brevibacterium, for which the names Brevibacterium
limosum sp. nov. (type strain o2T = JCM 33844T = MCCC
1A09961T), Brevibacterium pigmenatum sp. nov. (type strain
YB235T = JCM 33843T = MCCC 1A09842T) and Brevibacterium
atlanticum sp. nov. (type strain WO024T = JCM 33846T
= MCCC 1A16743T) are proposed.
Review
- Potential of Bacillus velezensis as a probiotic in animal feed: a review
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Fatima Khalid , Anam Khalid , Yuechi Fu , Qian Hu , Yunfang Zheng , Salman Khan , Zaigui Wang
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J. Microbiol. 2021;59(7):627-633. Published online July 1, 2021
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DOI: https://doi.org/10.1007/s12275-021-1161-1
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Abstract
- Bacillus velezensis is a plant growth-promoting bacterium that
can also inhibit plant pathogens. However, based on its properties,
it is emerging as a probiotic in animal feed. This review
focuses on the potential characteristics of B. velezensis
for use as a probiotic in the animal feed industry. The review
was conducted by collecting recently published articles from
peer-reviewed journals. Google Scholar and PubMed were
used as search engines to access published literature. Based
on the information obtained, the data were divided into three
groups to discuss the (i) probiotic characteristics of B. velezensis,
(ii) probiotic potential for fish, and (iii) the future potential
of this species to be developed as a probiotic for the
animal feed industry. Different strains of B. velezensis isolated
from different sources were found to have the ability to
produce antimicrobial compounds and have a beneficial effect
on the gut microbiota, with the potential to be a candidate
probiotic in the animal feed industry. This review provides
valuable information about the characteristics of B. velezensis,
which can provide researchers with a better understanding
of the use of this species in the animal feed industry.
Journal Articles
- Genetic changes in plaque-purified varicella vaccine strain Suduvax during in vitro propagation in cell culture
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Hye Rim Hwang , Se Hwan Kang , Chan Hee Lee
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J. Microbiol. 2021;59(7):702-707. Published online June 1, 2021
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DOI: https://doi.org/10.1007/s12275-021-1062-3
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Abstract
- Infection by varicella-zoster virus (VZV) can be prevented by
using live attenuated vaccines. VZV vaccine strains are known
to evolve rapidly in vivo, however, their genetic and biological
effects are not known. In this study, the plaque-purified vaccine
strain Suduvax (PPS) was used to understand the genetic
changes that occur during the process of propagation in in
vitro cell culture. Full genome sequences of three different passages
(p4, p30, and p60) of PPS were determined and compared
for genetic changes. Mutations were found at 59 positions.
The number of genetically polymorphic sites (GPS) and
the average of minor allele frequency (MAF) at GPSs were not
significantly altered after passaging in cell culture up to p60.
The number of variant nucleotide positions (VNPs), wherein
GPS was found in at least one passage of PPS, was 149. Overall,
MAF changed by less than 5% at 52 VNPs, increased by more
than 5% at 42 VNPs, and decreased by more than 5% at 55
VNPs in p60, compared with that seen in p4. More complicated
patterns of changes in MAF were observed when genetic
polymorphism at 149 VNPs was analyzed among the three
passages. However, MAF decreased and mixed genotypes became
unequivocally fixed to vaccine type in 23 vaccine-specific
positions in higher passages of PPS. Plaque-purified Suduvax
appeared to adapt to better replication during in vitro cell
culture. Further studies with other vaccine strains and in vivo
studies will help to understand the evolution of the VZV vaccine.
- Differences in seroprevalence between epicenter and non-epicenter areas of the COVID-19 outbreak in South Korea
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Hye Won Jeong , Hyun-Ha Chang , Eun Ji Kim , Yu Kyung Kim , Se-Mi Kim , Eun-Ha Kim , Young-Il Kim , Mark Anthony B. Casel , Seong-Gyu Kim , Rare Rollon , Seung-Gyu Jang , Kwang-Min Yu , Hee-Sung Kim , Hee Sue Park , Su-Jin Park , Yong-Dae Kim , Eung-Gook Kim , Young Ki Choi
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J. Microbiol. 2021;59(5):530-533. Published online April 28, 2021
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DOI: https://doi.org/10.1007/s12275-021-1095-7
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Abstract
- To compare the standardized severe acute respiratory syndrome
coronavirus 2 (SARS-CoV-2) seroprevalence of high
epicenter region with non-epicenter region, serological studies
were performed with a total of 3,268 sera from Daegu City
and 3,981 sera from Chungbuk Province. Indirect immunofluorescence
assay (IFA) for SARS-CoV-2 IgG results showed
a high seroprevalence rate in the Daegu City (epicenter) compared
with a non-epicenter area (Chungbuk Province) (1.27%
vs. 0.91%, P = 0.0358). It is noteworthy that the highest seroprevalence
in Daegu City was found in elderly patients (70’s)
whereas young adult patients (20’s) in Chungbuk Province
showed the highest seroprevalence. Neutralizing antibody
(NAb) titers were found in three samples from Daegu City
(3/3, 268, 0.09%) while none of the samples from Chungbuk
Province were NAb positive. These results demonstrated that
even following the large outbreak, the seropositive rate of
SARS-CoV-2 in the general population remained low in
South Korea.
Review
- [Minireview]Potential roles of condensin in genome organization and beyond in fission yeast
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Kyoung-Dong Kim
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J. Microbiol. 2021;59(5):449-459. Published online April 20, 2021
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DOI: https://doi.org/10.1007/s12275-021-1039-2
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Abstract
- The genome is highly organized hierarchically by the function
of structural maintenance of chromosomes (SMC) complex
proteins such as condensin and cohesin from bacteria
to humans. Although the roles of SMC complex proteins have
been well characterized, their specialized roles in nuclear processes
remain unclear. Condensin and cohesin have distinct
binding sites and mediate long-range and short-range genomic
associations, respectively, to form cell cycle-specific
genome organization. Condensin can be recruited to highly
expressed genes as well as dispersed repeat genetic elements,
such as Pol III-transcribed genes, LTR retrotransposon, and
rDNA repeat. In particular, mitotic transcription factors Ace2
and Ams2 recruit condensin to their target genes, forming
centromeric clustering during mitosis. Condensin is potentially
involved in various chromosomal processes such as the
mobility of chromosomes, chromosome territories, DNA reannealing,
and transcription factories. The current knowledge
of condensin in fission yeast summarized in this review can
help us understand how condensin mediates genome organization
and participates in chromosomal processes in other
organisms.
Journal Articles
- Adenosylhomocysteinase like 1 interacts with nonstructural 5A and regulates hepatitis C virus propagation
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Yun-Sook Lim , Han N. Mai , Lap P. Nguyen , Sang Min Kang , Dongseob Tark , Soon B. Hwang
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J. Microbiol. 2021;59(1):101-109. Published online December 23, 2020
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DOI: https://doi.org/10.1007/s12275-021-0470-8
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Abstract
- Hepatitis C virus (HCV) life cycle is highly dependent on cellular
proteins for viral propagation. In order to identify the
cellular factors involved in HCV propagation, we previously
performed a protein microarray assay using the HCV nonstructural
5A (NS5A) protein as a probe. Of ~9,000 human
cellular proteins immobilized in a microarray, adenosylhomocysteinase
like 1 (AHCYL1) was among 90 proteins identified
as NS5A interactors. Of these candidates, AHCYL1 was
selected for further study. In the present study, we verified
the physical interaction between NS5A and AHCYL1 by both
in vitro pulldown and coimmunoprecipitation assays. Furthermore,
HCV NS5A interacted with endogenous AHCYL1 in
Jc1-infected cells. Both NS5A and AHCYL1 were colocalized
in the cytoplasmic region in HCV-replicating cells. siRNAmediated
knockdown of AHCYL1 abrogated HCV propagation.
Exogenous expression of the siRNA-resistant AHCYL1
mutant, but not of the wild-type AHCYL1, restored HCV protein
expression levels, indicating that AHCYL1 was required
specifically for HCV propagation. Importantly, AHCYL1 was
involved in the HCV internal ribosome entry site-mediated
translation step of the HCV life cycle. Finally, we demonstrated
that the proteasomal degradation pathway of AHCYL1 was
modulated by persistent HCV infection. Collectively, these
data suggest that HCV may modulate the AHCYL1 protein
to promote viral propagation.
- Influence of dragon bamboo with different planting patterns on microbial community and physicochemical property of soil on sunny and shady slopes
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Weiyi Liu , Fang Wang , Yanmei Sun , Lei Yang , Huihai Chen , Weijie Liu , Bin Zhu , Chaomao Hui , Shiwei Wang
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J. Microbiol. 2020;58(11):906-914. Published online October 30, 2020
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DOI: https://doi.org/10.1007/s12275-020-0082-8
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Abstract
- Dragon bamboo (Dendrocalamus giganteus) is a giant sympodial
bamboo species widely distributed in Asia. However,
it remains unclear how dragon bamboo and soil microbes interact
to affect soil properties. In this study, we investigated
the planting patterns (semi-natural and artificial) on different
slopes (sunny and shady) to determine the effects on soil properties
and microbial community. The results showed that
the soil in which dragon bamboo was grown was acidic, with
a pH value of ~5. Also, the soil organic matter content, nitrogen
hydrolysate concentration, total nitrogen, available potassium,
and total potassium of the dragon bamboo seminatural
forest significantly improved, especially on the sunny
slope. In contrast, the available phosphorus level was higher
in the artificial bamboo forest, probably owing to the phosphate
fertilizer application. The bacterial and fungal diversity
and the bacterial abundance were all higher on the sunny
slope of the semi-natural forest than those in the other samples.
The microbial operational taxonomic units (OTUs)
shared between the shady and sunny slopes accounted for
47.8–62.2%, but the core OTUs of all samples were only 24.4–
30.4% of each sample, suggesting that the slope type had a
significant effect on the microbial community. Some acidophilic
microbes, such as Acidobacteria groups, Streptomyces
and Mortierella, became dominant in dragon bamboo forest
soil. A PICRUSt analysis of the bacterial functional groups
revealed that post-translational modification, cell division,
and coenzyme transport and metabolism were abundant in
the semi-natural forest. However, some microorganisms with
strong stress resistance might be activated in the artificial
forest. Taken together, these results illustrated the influence
of dragon bamboo growth on soil physicochemical property
and microbial community, which might help understand the
growth status of dragon bamboo under different planting
patterns.
- Biosynthesis of adipic acid in metabolically engineered Saccharomyces cerevisiae
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Xi Zhang , Yingli Liu , Jing Wang , Yunying Zhao , Yu Deng
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J. Microbiol. 2020;58(12):1065-1075. Published online October 23, 2020
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DOI: https://doi.org/10.1007/s12275-020-0261-7
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Abstract
- Adipic Acid (AA) is a valued platform chemical compound,
which can be used as a precursor of nylon-6,6. Due to the
generation of an enormous amount of nitric oxide metabolites
and the growing depletion of oil resources as a result of
AA production from a mixture of cyclohexanol and cyclohexanone,
the microbial methods for synthesizing AA have
attracted significant attention. Of the several AA-producing
pathways, the reverse adipate degradation pathway in
Thermobifida fusca (Tfu RADP) is reported to be the most
efficient, which has been confirmed in Escherichia coli. In this
study, the heterologous Tfu RADP was constructed for producing
AA in S. cerevisiae by co-expressing genes of Tfu_
0875, Tfu_2399, Tfu_0067, Tfu_1647, Tfu_2576, and Tfu_
2576. The AA titer combined with biomass, cofactors and
other by-products was all determined after fermentation.
During batch fermentation in a shake flask, the maximum AA
titer was 3.83 mg/L, while the titer increased to 10.09 mg/L
during fed-batch fermentation in a 5-L bioreactor after fermentation
modification.
- Anti-inflammatory and anti-oxidative effect of Korean propolis on Helicobacter pylori-induced gastric damage in vitro
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Moon-Young Song , Da-Young Lee , Eun-Hee Kim
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J. Microbiol. 2020;58(10):878-885. Published online September 2, 2020
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DOI: https://doi.org/10.1007/s12275-020-0277-z
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Abstract
- Helicobacter pylori, present in the stomach lining, is a Gramnegative
bacterium that causes various gastrointestinal diseases,
including gastritis and peptic ulcers. Propolis is a natural
resinous substance collected from a variety of plants,
and contains several natural bioactive substances. The aim of
this study was to investigate the anti-inflammatory and antioxidative
effects of Korean propolis on H. pylori-induced damage
in the human adenocarcinoma gastric cell line. The propolis
used in this study was obtained from the Korea Beekeeping
Association in South Korea. The expression of pro-inflammatory
interleukins (ILs), such as IL-8, IL-12, IL-1β, tumor
necrosis factor alpha, cyclooxygenase-2, and inducible
nitric oxide synthase, which was increased after H. pylori infection,
significantly decreased in a dose-dependent manner
upon pretreatment with Korean propolis, because of the suppression
of mitogen-activated protein kinases and nuclear
factor κB pathway. The anti-oxidative activity of propolis was
assessed using the 2,2-diphenyl-1-picrylhydrazyl hydrate free
radical assay. Korean propolis showed significant anti-oxidative
effects via reactive oxygen species scavenging. In addition,
pretreatment with Korean propolis upregulated the
expression of anti-oxidant enzymes through Nrf2 signaling
activation. These findings indicate that the use of Korean propolis,
which has anti-inflammatory and anti-oxidative effects,
can be promising for the prevention of H. pylori-induced gastric
damage.
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