Daiki Mizushima

Dr. Daiki Mizushima

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Research Focus & Metrics

Academic Career Length

12Years (2015-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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12 February 2015 in Letters in Applied Microbiology
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YKYosuke Kobayashi
Yosuke Kobayashi
HIHisashi Iwata
Hisashi Iwata
DMDaiki Mizushima
Daiki Mizushima
JOJun Ogihara
Jun Ogihara
TKTakafumi Kasumi
Takafumi Kasumi
The number of naphtha plants is being reduced due to a worldwide shift in energy sources. Consequently, a shortage of chemical materials heavily dependent on naphtha-oil, especially C4 compounds such as butene and butane-diol, is an urgent issue in chemical manufacturing. Erythritol is a rare C4 compound produced by fermentation processes using glucose as the carbon source. Since erythritol is considerably more expensive than hydrocarbons derived from naphtha-oil, a reduction in its cost is critical. We found that Moniliella megachiliensis, a highly osmotolerant yeast strain, can utilize nonrefined glycerol waste derived from palm oil or beef tallow and convert it to erythritol. Cell growth on glycerol was almost the same as on glucose, and the cells could grow in up to 300 mg ml(-1) glycerol. When 200 mg ml(-1) nonrefined glycerol was supplied, the yield of erythritol from the glycerol was approx. 60%, which is slightly higher than that obtained using glucose. The cost of glycerol waste is considerably lower than that of glucose. Thus, the conversion of glycerol waste into valuable erythritol, proposed here, is attractive and promising from the viewpoint of ensuring a supply of C4 hydrocarbons and utilizing a waste natural resource.A shortage of C4 hydrocarbon depending much on naptha-oil has become urgent problem due to rapid reduction of naphtha plants together with global energy revolution. Erythritol, obtained by fermentation, is a rare C4 polyol that can be converted to C4 hydrocarbons. Erythritol is considerably expensive than hydrocarbons, a reduction in cost is critical issue. To meet this, we proposed to utilize low-cost glycerol waste from bio-diesel fuel as a carbon source. Moniliella megachiliensis successfully converted glycerol waste to erythritol. This proposal is promising to obtain C4 hydrocarbon substitute, and concomitantly to dispose a large amount of glycerol waste discharged.

31 August 2023 in Parasites & Vectors
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ATAhmed Tabbabi
Ahmed Tabbabi
DMDaiki Mizushima
Daiki Mizushima
DYDaisuke S. Yamamoto
Daisuke S. Yamamoto
HKHirotomo Kato
Hirotomo Kato
Background: Blood-sucking phlebotomine sand flies are vectors of the protozoan parasites Leishmania spp. Although the intestinal microbiota is involved in a wide range of biological and physiological processes and has the potential to alter vector competence, little is known about the factors that modify the gut microbiota composition of sand flies. As a key step toward addressing this issue, we investigated the impact of host species on the gut bacterial composition in Phlebotomus and Lutzomyia sand flies reared under the same conditions. Methods: Bacterial 16S rRNA gene amplification and Illumina MiSeq sequencing were used to characterize the overall bacterial composition of three laboratory-reared sandflies: Phlebotomus papatasi, Ph. duboscqi, and Lutzomyia longipalpis. Results: Our results showed that the larvae of the three sand fly species harbored almost the same microbes but had different relative abundances. Adult Ph. papatasi and Ph. duboscqi revealed similar microbiome compositions, which were distinct from that of adult Lu. longipalpis. Furthermore, we showed that Ph. papatasi and Ph. duboscqi are hosts for different bacterial genera. The experiment was repeated twice to improve accuracy and increase reliability of the data, and the same results were obtained even when a distinct composition of the microbiome among the same species was identified probably because of the use of different larvae food batch. Conclusions: The present study provides key insights into the role of host species in the gut microbial content of different sand fly species reared under the same conditions, which may influence their susceptibility to Leishmania infection. Graphical

28 April 2017 in Bioscience Reports
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ZFZui Fujimoto
Zui Fujimoto
NKNaomi Kishine
Naomi Kishine
NSNobuhiro Suzuki
Nobuhiro Suzuki
RSRyuichiro Suzuki
Ryuichiro Suzuki
DMDaiki Mizushima
Daiki Mizushima
KFKazumi Funane
Kazumi Funane
Paenibacillus sp. 598K cycloisomaltooligosaccharide glucanotransferase (CITase), a member of glycoside hydrolase family 66 (GH66), catalyses the intramolecular transglucosylation of dextran to produce CIs with seven or more degrees of polymerization. To clarify the cyclization reaction and product specificity of the enzyme, we determined the crystal structure of PsCITase. The core structure of PsCITase consists of four structural domains: a catalytic (β/α)8-domain and three β-domains. A family 35 carbohydrate-binding module (first CBM35 region of Paenibacillus sp. 598K CITase, (PsCBM35-1)) is inserted into and protrudes from the catalytic domain. The ligand complex structure of PsCITase prepared by soaking the crystal with cycloisomaltoheptaose yielded bound sugars at three sites: in the catalytic cleft, at the joint of the PsCBM35-1 domain and at the loop region of PsCBM35-1. In the catalytic site, soaked cycloisomaltoheptaose was observed as a linear isomaltoheptaose, presumably a hydrolysed product from cycloisomaltoheptaose by the enzyme and occupied subsites –7 to –1. Beyond subsite –7, three glucose moieties of another isomaltooiligosaccharide were observed, and these positions are considered to be distal subsites –13 to –11. The third binding site is the canonical sugar-binding site at the loop region of PsCBM35-1, where the soaked cycloisomaltoheptaose is bound. The structure indicated that the concave surface between the catalytic domain and PsCBM35-1 plays a guiding route for the long-chained substrate at the cyclization reaction.

19 October 2020 in PLOS Neglected Tropical Diseases
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ATAhmed Tabbabi
Ahmed Tabbabi
ALAbraham Caceres Lazaro
Abraham Caceres Lazaro
TCT. Pershing Bustamante Chauca
T. Pershing Bustamante Chauca
CSChisato Seki
Chisato Seki
YCYanisa Choochartpong
Yanisa Choochartpong
HKHirotomo Kato
Hirotomo Kato
Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis of the mannose phosphate isomerase (mpi) gene was applied to 134 skin samples collected from patients with cutaneous leishmaniasis (CL) in Peru for identification of the infecting parasite at the species level, and the results were compared with those of cytochrome b (cyt b) gene sequencing obtained in previous studies. Although most results (121/134) including 4 hybrids of Leishmania (Viannia) braziliensis and L. (V.) peruviana corresponded to those obtained in the previous study, PCR-RFLP analyses revealed the distribution of putative hybrid strains between L. (V.) peruviana and L. (V.) lainsoni in two samples, which has never been reported. Moreover, parasite strains showing discordance between kinetoplast and nuclear genes (kDNA and nDNA), so-called mito-nuclear discordance, were identified in 11 samples. Of these, six strains had the kDNAs of L. (V.) braziliensis or L. (V.) peruviana and nDNAs of L. (V.) guyanensis, and three strains had the kDNAs of L. (V.) shawi and nDNAs of L. (V.) braziliensis. The rest were identified as mito-nuclear discordance strains having kDNAs of L. (V.) braziliensis or L. (V.) peruviana and nDNAs of L. (V.) lainsoni, and kDNAs of L. (V.) lainsoni and nDNAs of L. (V.) braziliensis. The results demonstrate that Leishmania strains in Peru are genetically more complex than previously considered. Protozoan parasites of the genus Leishmania are able to undergo genetic exchange during their growth. The previous description of hybrids in Peru and the recent discovery of unexpected genetically complex strains having characteristics of both hybrid and mito-nuclear discordance in its neighbouring country (Ecuador) with a similar eco-epidemiological situation led us to consider that the genetic structure of Leishmania strains in Peru is more complicated than previously thought. In an effort to revise the data on Leishmania strain dispersion in Peru and to search for evidence of genetic recombination, the present study was conducted. A polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis targeting the mannose phosphate isomerase (mpi) gene sequence was performed to identify the infecting parasite at the species level in 134 skin samples collected from patients with cutaneous leishmaniasis (CL) in Peru, and the results were compared with those of cytochrome b (cyt b) gene sequencing obtained in previous studies. Most results (121/134) including 4 hybrids between L. (V.) braziliensis and L. (V.) peruviana showed agreement between PCR-RFLP of the mpi gene and cyt b gene sequence analysis; however, 13 of 134 samples revealed the distribution of strains with hybrids and mito-nuclear discordance. The results demonstrate that genetically complex Leishmania strains are present in Peru. These findings indicate that Leishmania strain dispersion in Peru is genetically more complex than previously considered. Further prospective studies including larger samples and the isolation of parasite strains are required to update the available data.


11 April 2022 in Parasitologia
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ATAhmed Tabbabi
Ahmed Tabbabi
DMDaiki Mizushima
Daiki Mizushima
DYDaisuke S. Yamamoto
Daisuke S. Yamamoto
HKHirotomo Kato
Hirotomo Kato
Sand flies are a significant public health concern in many parts of the world where they are known to transmit agents of several zoonotic diseases to humans, such as leishmaniasis. Vector control remains a key component of many anti-leishmaniasis programs and probably will remain so until an effective vaccine becomes available. The sand fly gut microbiota has recently emerged as an encouraging field for the exploration of vector-based disease control. In particular, the gut microbiome was previously reported to either enhance or inhibit parasite activity depending on the species of bacteria and, thus, has the potential to alter vector competence. Here, we describe the technological advances that are currently expanding our understanding of microbiota composition in sand flies. The acquisition and composition of microbiomes are influenced by several abiotic and biotic factors, including host immunity, genetics, and the environment. Therefore, the microbiomes of sand flies can vary substantially between individuals, life stages, species, and over geographical space, and this variation likely contributes to differences in host phenotypes, highlighting opportunities for novel vector control strategies.