Journal Articles
- In Silico Intensive Analysis for the E4 Gene Evolution of Human Adenovirus Species D.
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Chanhee Lee, Anyeseu Park, Jeong Yoon Lee
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J. Microbiol. 2024;62(5):409-418. Published online April 30, 2024
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DOI: https://doi.org/10.1007/s12275-024-00132-1
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Abstract
- Adenovirus (Ad) is a ubiquitous pathogen capable of infecting a wide range of animals and humans. Human Adenovirus (HAdV) can cause severe infection, particularly in individuals with compromised immune systems. To date, over 110 types of HAdV have been classified into seven species from A to G, with the majority belonging to the human adenovirus species D (HAdV-D). In the HAdV-D, the most significant factor for the creation of new adenovirus types is homologous recombination between viral genes involved in determining the virus tropism or evading immune system of host cells. The E4 gene, consisting of seven Open Reading Frames (ORFs), plays a role in both the regulation of host cell metabolism and the replication of viral genes. Despite long-term studies, the function of each ORF remains unclear. Based on our updated information, ORF2, ORF3, and ORF4 have been identified as regions with relatively high mutations compared to other ORFs in the E4 gene, through the use of in silico comparative analysis. Additionally, we managed to visualize high mutation sections, previously undetectable at the DNA level, through a powerful amino acid sequence analysis tool known as proteotyping. Our research has revealed the involvement of the E4 gene in the evolution of human adenovirus, and has established accurate sequence information of the E4 gene, laying the groundwork for further research.
- Assessment of Cre-lox and CRISPR-Cas9 as tools for recycling of multiple-integrated selection markers in Saccharomyces cerevisiae
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Hye Yun Moon† , Gyu Hun Sim† , Hyeon Jin Kim , Keunpil Kim , Hyun Ah Kang
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J. Microbiol. 2022;60(1):18-30. Published online December 29, 2021
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DOI: https://doi.org/10.1007/s12275-022-1580-7
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Abstract
- We evaluated the Cre-lox and CRISPR-Cas9 systems as markerrecycling
tools in Saccharomyces cerevisiae recombinants containing
multiple-integrated expression cassettes. As an initial
trial, we constructed rDNA-nontranscribed spacer- or Ty4-
based multiple integration vectors containing the URA3 marker
flanked by the loxP sequence. Integrants harboring multiple
copies of tHMG1 and NNV-CP expression cassettes were obtained
and subsequently transformed with the Cre plasmid.
However, the simultaneous pop-out of the expression cassettes
along with the URA3 marker hampered the use of Cre-lox as
a marker-recycling tool in multiple integrants. As an alternative,
we constructed a set of CRISPR-Cas9-gRNA vectors containing
gRNA targeted to auxotrophic marker genes. Transformation
of multiple integrants of tHMG1 and NNV-CP
cassettes by the Cas9-gRNA vector in the presence of the URA3
(stop) donor DNA fragments generated the Ura- transformants
retaining multiple copies of the expression cassettes.
CRISPR-Cas9-based inactivation led to the recycling of the
other markers, HIS3, LEU2, and TRP1, without loss of expression
cassettes in the recombinants containing multiple
copies of tHMG1, NNV-CP, and SfBGL1 cassettes, respectively.
Reuse of the same selection marker in marker-inactivated
S. cerevisiae was validated by multiple integrations of the
TrEGL2 cassette into the S. cerevisiae strain expressing SfBGL1.
These results demonstrate that introducing stop codons into
selection marker genes using the CRISPR-Cas9 system with
donor DNA fragments is an efficient strategy for markerrecycling
in multiple integrants. In particular, the continual
reuse of auxotrophic markers would facilitate the construction
of a yeast cell factory containing multiple copies of expression
cassettes without antibiotic resistance genes.
- Similarities and differences between 6S RNAs from Bradyrhizobium japonicum and Sinorhizobium meliloti
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Olga Y. Burenina , Daria A. Elkina , Anzhela Y. Migur , Tatiana S. Oretskaya , Elena Evguenieva-Hackenberg , RolK. Hartmann , Elena A. Kubareva
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J. Microbiol. 2020;58(11):945-956. Published online October 30, 2020
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DOI: https://doi.org/10.1007/s12275-020-0283-1
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Abstract
- 6S RNA, a conserved and abundant small non-coding RNA
found in most bacteria, regulates gene expression by inhibiting
RNA polymerase (RNAP) holoenzyme. 6S RNAs from
α-proteobacteria have been studied poorly so far. Here, we
present a first in-depth analysis of 6S RNAs from two α-proteobacteria
species, Bradyrhizobium japonicum and Sinorhizobium
meliloti. Although both belong to the order Rhizobiales
and are typical nitrogen-fixing symbionts of legumes,
their 6S RNA expression profiles were found to differ: B. japonicum
6S RNA accumulated in the stationary phase, thus
being reminiscent of Escherichia coli 6S RNA, whereas S. meliloti
6S RNA level peaked at the transition to the stationary
phase, similarly to Rhodobacter sphaeroides 6S RNA. We demonstrated
in vitro that both RNAs have hallmarks of 6S
RNAs: they bind to the σ70-type RNAP holoenzyme and serve
as templates for de novo transcription of so-called product
RNAs (pRNAs) ranging in length from ~13 to 24 nucleotides,
with further evidence of the synthesis of even longer pRNAs.
Likewise, stably bound pRNAs were found to rearrange the
6S RNA structure to induce its dissociation from RNAP.
Compared with B. japonicum 6S RNA, considerable conformational
heterogeneity was observed for S. meliloti 6S RNA
and its complexes with pRNAs, even though the two 6S RNAs
share ~75% sequence identity. Overall, our findings suggest
that the two rhizobial 6S RNAs have diverged with respect to
their regulatory impact on gene expression throughout the
bacterial life cycle.
- Promising cellulolytic fungi isolates for rice straw degradation
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Diana Catalina Pedraza-Zapata , Andrea Melissa Sánchez-Garibello , Balkys Quevedo-Hidalgo , Nubia Moreno-Sarmiento , Ivonne Gutiérrez-Rojas
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J. Microbiol. 2017;55(9):711-719. Published online September 2, 2017
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DOI: https://doi.org/10.1007/s12275-017-6282-1
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Abstract
- The objective of this study was to evaluate the potential of
eight fungal isolates obtained from soils in rice crops for straw
degradation in situ. From the initial eight isolates, Pleurotus
ostreatus T1.1 and Penicillium sp. HC1 were selected for further
characterization based on qualitative cellulolytic enzyme
production and capacity to use rice straw as a sole carbon
source. Subsequently, cellulolytic, xylanolytic, and lignolytic
(Pleurotus ostreatus) activity on carboxymethyl cellulose,
oat xylan, and rice straw with different nitrogen sources was
evaluated. From the results obtained it was concluded both
isolates are capable to produce enzymes necessary for rice
straw degradation. However, their production is dependent
upon carbon and nitrogen source. Last, it was established
that Pleurotus ostreatus T1.1 and Penicillium sp. HC1 capability
to colonize and mineralize rice straw, in mono-and
co-culture, without affecting nitrogen soil content.
- Optimization of Enterobacter cloacae (KU923381) for diesel oil degradation using Response Surface Methodology (RSM)
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Sugumar Ramasamy , Arumugam Arumugam , Preethy Chandran
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J. Microbiol. 2017;55(2):104-111. Published online January 26, 2017
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DOI: https://doi.org/10.1007/s12275-017-6265-2
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45
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Abstract
- Efficiency of Enterobacter cloacae KU923381 isolated from
petroleum hydrocarbon contaminated soil was evaluated in
batch culture and bioreactor mode. The isolate were screened
for biofilm formation using qualitative and quantitative assays.
Response surface methodology (RSM) was used to study the
effect of pH, temperature, glucose concentration, and sodium
chloride on diesel degradation. The predicted values for
diesel oil degradation efficiency by the statistical designs are
in a close agreement with experimental data (R2 = 99.66%).
Degradation efficiency is increased by 36.78% at pH = 7,
temperature = 35°C, glucose = 5%, and sodium chloride concentration
= 5%. Under the optimized conditions, the experiments
were performed for diesel oil degradation by gas chromatographic
mass spectrometric analysis (GC-MS). GC-MS
analysis confirmed that E. cloacae had highly degrade hexadecane,
heptadecane, tridecane, and docosane by 99.71%,
99.23%, 99.66%, and 98.34% respectively. This study shows
that rapid bioremoval of hydrocarbons in diesel oil is acheived
by E. cloacae with abet of biofilm formation. The potential
use of the biofilms for preparing trickling filters (gravel particles)
for the degradation of hydrocarbons from petroleum
wastes before their disposal in the open environment is highly
suggested. This is the first successful attempt for artificially
establishing petroleum hydrocarbon degrading bacterial biofilm
on solid substrates in bioreactor.
- Application of Response Surface Methodology for Rapid Chrysene Biodegradation by Newly Isolated Marine-derived Fungus Cochliobolus lunatus Strain CHR4D
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Jwalant K. Bhatt , Chirag M. Ghevariya , Dushyant R. Dudhagara , Rahul K. Rajpara , Bharti P. Dave
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J. Microbiol. 2014;52(11):908-917. Published online October 31, 2014
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DOI: https://doi.org/10.1007/s12275-014-4137-6
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Abstract
- For the first time, Cochliobolus lunatus strain CHR4D, a marine-derived ascomycete fungus isolated from historically contaminated crude oil polluted shoreline of Alang-Sosiya ship-breaking yard, at Bhavnagar coast, Gujarat has been reported showing the rapid and enhanced biodegradation of chrysene, a four ringed high molecular weight (HMW) polycyclic aromatic hydrocarbon (PAH). Mineral Salt Broth (MSB) components such as ammonium tartrate and glucose along with chrysene, pH and trace metal solution have been successfully optimized by Response Surface Methodology (RSM) using central composite design (CCD). A validated, two-step optimization protocol has yielded a substantial 93.10% chrysene degradation on the 4th day, against unoptimized 56.37% degradation on the 14th day. The results
depict 1.65 fold increase in chrysene degradation and 1.40 fold increase in biomass with a considerable decrement in time. Based on the successful laboratory experiments, C. lunatus strain CHR4D can thus be predicted as a potential
candidate for mycoremediation of HMW PAHs impacted environments.
Research Support, Non-U.S. Gov'ts
- Biodegradation of C5-C8 Fatty Acids and Production of Aroma Volatiles by Myroides sp. ZB35 Isolated from Activated Sludge
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Zijun Xiao , Xiankun Zhu , Lijun Xi , Xiaoyuan Hou , Li Fang , Jian R. Lu
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J. Microbiol. 2014;52(5):407-412. Published online May 9, 2014
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DOI: https://doi.org/10.1007/s12275-014-4109-x
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Abstract
- In the effluents of a biologically treated wastewater from a heavy oil-refining plant, C5-C8 fatty acids including penta-noic acid, hexanoic acid, heptanoic acid, octanoic acid, and 2-methylbutanoic acid are often detected. As these residual fatty acids can cause further air and water pollution, a new Myroides isolate ZB35 from activated sludge was explored to degrade these C5-C8 fatty acids in this study. It was found that the biodegradation process involved a lag phase that became prolonged with increasing acyl chain length when the fatty acids were individually fed to this strain. However, when fed as a mixture, the ones with longer acyl chains were found to become more quickly assimilated. The branched 2- methylbutanoic acid was always the last one to be depleted among the five fatty acids under both conditions. Metabolite analysis revealed one possible origin of short chain fatty acids in the biologically treated wastewater. Aroma volatiles inclu-ding 2-methylbutyl isovalerate, isoamyl 2-methylbutanoate, isoamyl isovalerate, and 2-methylbutyl 2-methylbutanoate were subsequently identified from ZB35 extracts, linking the source of the fruity odor to these esters excreted by Myroides species. To our best knowledge, this is the first finding of these aroma esters in bacteria. From a biotechnological viewpoint, this study has revealed the potential of Myroides species as a promising source of aroma esters attractive for food and fragrance industries.
- Molecular Characterization of the Alpha Subunit of Multicomponent Phenol Hydroxylase from 4-Chlorophenol-Degrading Pseudomonas sp. Strain PT3
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Wael S. El-Sayed , Mohamed K. Ibrahim , Salama A. Ouf
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J. Microbiol. 2014;52(1):13-19. Published online January 4, 2014
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DOI: https://doi.org/10.1007/s12275-014-3250-x
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Abstract
- Multicomponent phenol hydroxylases (mPHs) are diiron
enzymes that use molecular oxygen to hydroxylate a variety
of phenolic compounds. The DNA sequence of the alpha
subunit (large subunit) of mPH from 4-chlorophenol (4-CP)-
degrading bacterial strain PT3 was determined. Strain PT3
was isolated from oil-contaminated soil samples adjacent
to automobile workshops and oil stations after enrichment
and establishment of a chlorophenol-degrading consortium.
Strain PT3 was identified as a member of Pseudomonas sp.
based on sequence analysis of the 16S rRNA gene fragment.
The 4-CP catabolic pathway by strain PT3 was tentatively
proposed to proceed via a meta-cleavage pathway after hydroxylation
to the corresponding chlorocatechol. This hypothesis
was supported by polymerase chain reaction (PCR)
detection of the LmPH encoding sequence and UV/VIS spectrophotometric
analysis of the culture filtrate showing accumulation
of 5-chloro-2-hydroxymuconic semialdehyde
(5-CHMS) with λmax 380. The detection of catabolic genes
involved in 4-CP degradation by PCR showed the presence of
both mPH and catechol 2,3-dioxygenase (C23DO). Nucleotide
sequence analysis of the alpha subunit of mPH from strain
PT3 revealed specific phylogenetic grouping to known mPH.
The metal coordination encoding regions from strain PT3
were found to be conserved with those from the homologous
dinuclear oxo-iron bacterial monooxygenases. Two
DE(D)XRH motifs was detected in LmPH of strain PT3
within an approximate 100 amino acid interval, a typical
arrangement characteristic of most known PHs.
Journal Article
- Comparative Study of Olive Oil Mill Wastewater Treatment Using Free and Immobilized Coriolopsis polyzona and Pycnoporus coccineus
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Mohamed Neifar , Atef Jaouani , María Jesús Martínez , Michel J. Penninckx
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J. Microbiol. 2012;50(5):746-753. Published online November 4, 2012
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DOI: https://doi.org/10.1007/s12275-012-2079-4
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Abstract
- The efficiency of the two white-rot fungi Pycnoporus coccineus and Coriolopsis polyzona in the Olive Oil Mill Wastewater (OOMW) treatment was investigated. Both fungi were active in the decolourisation and COD removal of OOMW at 50 g/L COD, but only the first fungus remains effective on the crude effluent (COD=100 g/L). Moreover P. coccineus was less affected by oxygen supplementation and exhibited a high tolerance to agitation in comparison to C. polyzona. However, it required a nitrogen supplementation to obtain faster and higher COD removal. To overcome the negative effect of agitation on fungi growth and efficiency, immobilisation of C. polyzona and P. coccineus in polyurethane foam was applied. The immobilized system showed better COD decreases during three consecutive batches without remarkable loss of performances. The results obtained in this study suggested that immobilized C. polyzona and especially immobilized P. coccineus might be applicable to a large scale for the removal colour and COD of OOMW.
Research Support, Non-U.S. Gov'ts
- Molecular Characterization of Chloranilic Acid Degradation in Pseudomonas putida TQ07
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Luis G. Treviño-Quintanilla , Julio A. Freyre-González , Rosa A. Guillén-Garcés , Clarita Olvera
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J. Microbiol. 2011;49(6):974-980. Published online December 28, 2011
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DOI: https://doi.org/10.1007/s12275-011-1507-1
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Abstract
- Pentachlorophenol is the most toxic and recalcitrant chlorophenol because both aspects are directly proportional to the halogenation degree. Biological and abiotic pentachlorophenol degradation generates p-chloranil, which in neutral to lightly alkaline environmental conditions is hydrolyzed to chloranilic acid that present a violet-reddish coloration in aqueous solution. Several genes of the degradation pathway, cadR-cadCDX, as well as other uncharacterized genes (ORF5 and 6), were isolated from a chloranilic acid degrading bacterium, Pseudomonas putida strain TQ07. The disruption by random mutagenesis of the cadR and cadC genes in TQ07 resulted in a growth deficiency in the presence of chloranilic acid, indicating that these genes are essential for TQ07 growth with chloranilic acid as the sole carbon source. Complementation assays demonstrated that a transposon insertion in mutant CAD82 (cadC) had a polar effect on other genes contained in cosmid pLG3562. These results suggest that at least one of these genes, cadD and cadX, also takes part in chloranilic acid degradation. Based on molecular modeling and function prediction, we strongly suggest that CadC is a pyrone dicarboxylic acid hydrolase and CadD is an aldolase enzyme like dihydrodipicolinate synthase. The results of this study allowed us to propose a novel pathway that offers hypotheses on chloranilic acid degradation (an abiotic by-product of pentachlorophenol) by means of a very clear phenotype that is narrowly related to the capability of Pseudomonas putida strain TQ07 to degrade this benzoquinone.
- Isolation and Characterization of Ethylbenzene Degrading Pseudomonas putida E41
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Lan-Hee Kim , Sang-Seob Lee
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J. Microbiol. 2011;49(4):575-584. Published online September 2, 2011
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DOI: https://doi.org/10.1007/s12275-011-0399-4
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Abstract
- Pseudomonas putida E41 was isolated from oil-contaminated soil and showed its ability to grow on ethylbenzene
as the sole carbon and energy source. Moreover, P. putida E41 show the activity of biodegradation
of ethylbenzene in the batch culture. E41 showed high efficiency of biodegradation of ethylbenzene with
the optimum conditions (a cell concentration of 0.1 g wet cell weight/L, pH 7.0, 25°C, and ethylbenzene
concentration of 50 mg/L) from the results of the batch culture. The maximum degradation rate and specific
growth rate (μmax) under the optimum conditions were 0.19±0.03 mg/mg-DCW (Dry Cell Weight)/h and
0.87±0.13 h-1, respectively. Benzene, toluene and ethylbenzene were degraded when these compounds were
provided together; however, xylene isomers persisted during degradation by P. putida E41. When using
a bioreactor batch system with a binary culture with P. putida BJ10, which was isolated previously in
our lab, the degradation rate for benzene and toluene was improved in BTE mixed medium (each initial
concentration: 50 mg/L). Almost all of the BTE was degraded within 4 h and 70-80% of m-, p-, and o-xylenes
within 11 h in a BTEX mixture (initial concentration: 50 mg/L each). In summary, we found a valuable
new strain of P. putida, determined the optimal degradation conditions for this isolate and tested a mixed
culture of E41 and BJ10 for its ability to degrade a common sample of mixed contaminants containing
benzene, toluene, and xylene.
- Acinetobacter oleivorans sp. nov. Is Capable of Adhering to and Growing on Diesel-Oil
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Yoon-Suk Kang , Jaejoon Jung , Che Ok Jeon , Woojun Park
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J. Microbiol. 2011;49(1):29-34. Published online March 3, 2011
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DOI: https://doi.org/10.1007/s12275-011-0315-y
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Abstract
- A diesel-oil and n-hexadecane-degrading novel bacterial strain, designated DR1T, was isolated from a rice paddy in Deok-So, South Korea. The strain DR1T cells were Gram-negative, aerobic coccobacilli, and grew at 20-37°C with the optimal temperature of 30°C, and an optimal pH of 6-8. Interestingly, strain DR1T was highly motile (swimming and swarming motility) using its fimbriae, and generated N-acyl homoserine lactones as quorum-sensing signals. The predominant respiratory quinone as identified as ubiquinone-9 (Q-9) and DNA G+C content was 41.4 mol%. Comparative 16S rRNA gene sequence-based phylogenetic analysis placed the strain in a clade with the species A. calcoaceticus, A. haemolyticus, A. baumannii, A. baylyi, and A. beijerinckii, with which it evidenced sequence similarities of 98.2%, 97.4%, 97.2%, 97.1%, and 97.0%, respectively. DNA-DNA hybridization values between strain DR1T and other Acinetobacter spp. were all less than 20%. The physiological and taxonomic characteristics with the DNA-DNA hybridization data supported the identification of strain DR1T in the genus Acinetobacter as a novel species, for which the name Acinetobacter oleivorans sp. nov. is proposed. The type strain is DR1T (=KCTC 23045T =JCM 16667T).
- Effect of Fungal Pellet Morphology on Enzyme Activities Involved in Phthalate Degradation
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Young-Mi Kim , Hong-Gyu Song
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J. Microbiol. 2009;47(4):420-424. Published online September 9, 2009
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DOI: https://doi.org/10.1007/s12275-009-0051-8
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Abstract
- Pellet size of white rot fungus, Pleurotus ostreatus may affect the secretion of its degradative enzymes and accompanying biodegrading capability, but could be controlled by several physical culture conditions in liquid culture. The pellet size of P. ostreatus was affected by the volume of inoculum, flask, and medium, but the agitation speed was the most important control factor. At the lower agitation speed of 100 rpm, the large pellets were formed and the laccase activity was higher than that of small pelleted culture at 150 rpm, which might be due to loose intrapellet structure. However, the biodegradation rates of benzylbutylphthalate and dimethylphthalate were higher in the small pelleted culture, which indicated the involvement of other degradative enzyme rather than laccase. The activity of esterase which catalyzes the nonphenolic compounds before the reaction of ligninolytic enzymes was higher in the small pelleted culture, and coincided with the degradation pattern of phthalates. This study suggests the optimization of pellet morphology and subsequent secretion of degradative enzymes is necessary for the efficient removal of recalcitrants by white rot fungi.
Journal Article
- Monitoring Nutrient Impact on Bacterial Community Composition during Bioremediation of Anoxic PAH-Contaminated Sediment
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Myungsu Kim , Seung Seob Bae , Mijin Seol , Jung-Hyun Lee , Young-Sook Oh
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J. Microbiol. 2008;46(6):615-623. Published online December 24, 2008
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DOI: https://doi.org/10.1007/s12275-008-0097-z
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Abstract
- Marine harbor sediments are frequently polluted with significant amount of polycyclic aromatic hydrocarbons (PAHs) some of which are naturally toxic, recalcitrant, mutagenic, and carcinogenic. To stimulate biodegradation of PAHs in PAH-contaminated sediments collected from near Gwangyang Bay, Korea, lactate was chosen as a supplementary carbonaceous substrate. Sediment packed into 600 ml air-tight jar was either under no treatment condition or lactate amended condition (1%, w/v). Microbial community composition was monitored by bacteria-specific and archaea-specific PCR-terminal restriction fragment length polymorphism (T-RFLP), in addition to measuring the residual PAH concentration. Results showed that lactate amendment enhanced biodegradation rate of PAHs in the sediment by 4 to 8 times, and caused a significant shift in archaebacterial community in terms of structure and diversity with time. Phylogenetic analysis of 23 archaeal clones with distinctive RFLP patterns among 288 archaeal clones indicated that majority of the archaeal members were closest to unculturable environmental rDNA clones from hydrocarbon-contaminated and/or methanogenesis-bearing sediments. Lactate amendment led to the enrichment of some clones that were most closely related to PAH-degrading Methanosarcina species. These results suggest a possible contribution of methanogenic community to PAH degradation and give us more insights on how to effectively remediate PAH-contaminated sediments.
Review
- Biosynthesis, Modification, and Biodegradation of Bacterial Medium-Chain-Length Polyhydroxyalkanoates
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Do Young Kim , Hyung Woo Kim , Moon Gyu Chung , Young Ha Rhee
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J. Microbiol. 2007;45(2):87-97.
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DOI: https://doi.org/2528 [pii]
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Abstract
- Medium-chain-length polyhydroxyalkanoates (MCL-PHAs), which have constituents with a typical chain length of C6-C14, are polyesters that are synthesized and accumulated in a wide variety of Gram-negative bacteria, mainly pseudomonads. These biopolyesters are promising materials for various applications because they have useful mechanical properties and are biodegradable and biocompatible. The versatile metabolic capacity of some Pseudomonas spp. enables them to synthesize MCL-PHAs that contain various functional substituents; these MCL-PHAs are of great interest because these functional groups can improve the physical properties of the polymers, allowing the creation of tailor-made products. Moreover, some functional substituents can be modified by chemical reactions to obtain more useful groups that can extend the potential applications of MCL-PHAs as environmentally friendly polymers and functional biomaterials for use in biomedical fields. Although MCL-PHAs are water-insoluble, hydrophobic polymers, they can be degraded by microorganisms that produce extracellular MCL-PHA depolymerase. MCL-PHA-degraders are relatively uncommon in natural environments and, to date, only a limited number of MCL-PHA depolymerases have been investigated at the molecular level. All known MCL-PHA depolymerases share a highly significant similarity in amino acid sequences, as well as several enzymatic characteristics. This paper reviews recent advances in our knowledge of MCL-PHAs, with particular emphasis on the findings by our research group.