MyMedR

Displaying all 4 publications

Abstract:

Sort:

Direct production of polyhydroxybutyrate from waste starch by newly-isolated Bacillus aryabhattai T34-N4

Bomrungnok W, Arai T, Yoshihashi T, Sudesh K, Hatta T, Kosugi A

Environ Technol, 2020 Nov;41(25):3318-3328.
PMID: 30987543 DOI: 10.1080/09593330.2019.1608314

Polyhydroxybutyrate (PHB) is a natural microbial polyester produced by a variety of bacteria and archaea from renewable resources. PHB resembles some petrochemical plastics but is completely biodegradable. It is desirable to identify suitable microbial strains and develop processes that can directly use starch from agricultural wastes without commercial amylase treatment. Here, PHB production using starch from agricultural waste was developed using a newly isolated strain, Bacillus aryabhattai T34-N4. This strain hydrolyzed cassava pulp and oil palm trunk starch and accumulated up to 17 wt% PHB of the cell dry weight. The α-amylase of this strain, AmyA, showed high activity in the presence of cassava pulp starch (69.72 U) and oil palm trunk starch (70.53 U). High expression of amyA was recorded in the presence of cassava pulp starch, whereas low expression was detected in the presence of glucose. These data suggest that starch saccharification by amyA allows strain T34-N4 to grow and directly produce PHB from waste starch materials such as cassava pulp and oil palm trunk starch, which may be used as low-cost substrates.
First detection and molecular identification of Entamoeba bovis from Japanese cattle

Matsubayashi M, Matsuura Y, Nukata S, Daizi Y, Shibahara T, Teramoto I, et al.

Parasitol Res, 2018 Jan;117(1):339-342.
PMID: 29185030 DOI: 10.1007/s00436-017-5689-2

Thus far, Entamoeba species have been classified based on morphology such as the number of nuclei in mature cysts and their hosts. Using recently developed molecular tools, ruminant Entamoeba spp. are currently classified into four species/genotypes: E. bovis and Entamoeba ribosomal lineages (RL) 1, 2, and 4. However, the distribution or pathogenicity of ruminant Entamoeba has not been well documented. In the present study, we examined a total of 25 fecal and seven environmental samples collected from six farms in Japan from 2016 to 2017 by the floatation method and PCR and sequencing analyses. Consequently, we detected Entamoeba cysts in 18 of 25 cattle samples and four of the seven environmental samples, including soil and drinking water, by microscopic examinations. In sequential examinations, Entamoeba-positive cattle were found to shed cysts without any clinical symptoms for more than 8 months. By PCR for molecular identification, isolates in ten cattle and one soil sample were successfully sequenced and formed a cluster of E. bovis, which was separated from those of other Entamoeba species/genotypes such as RL1-4 in phylogenetic analysis. To our knowledge, this is the first report about E. bovis in Japan, and our results may implicate that E. bovis is not pathogenic.
Evaluation of the detection method by a flotation method using a wire loop for gastrointestinal parasites

Takano A, Morinaga D, Teramoto I, Hatabu T, Kido Y, Kaneko A, et al.

Vet Med Sci, 2024 Sep;10(5):e70007.
PMID: 39207196 DOI: 10.1002/vms3.70007

Infections by gastrointestinal parasites are found in a variety of animals worldwide. For the diagnosis of such infections, the flotation method is commonly used to detect parasitic microorganisms, such as oocysts or eggs, in feces. Instead of adding a flotation solution after the final centrifugation step and using a cover slip to collect the parasites, the method using a wire loop for the recovery of the organisms has been reported as one of alternative methods. However, the recovery rates of microorganisms from the flotation method have not been analysed. In the present study, the utility of a flotation method with the use of a wire loop of 8 mm in diameter (the loop method) was evaluated using different numbers of E. tenella oocysts and Heterakis gallinarum eggs, and chicken fecal samples collected at the farms. Consequently, we found that the oocysts and eggs in tubes could be collected at a ratio of 2.00 to 3.08. Thus, our results indicate that the loop method is a simple and time saving method, implicating the application for the estimated OPG/ EPG (Oocysts/Eggs per gram) of the samples.
Detection of Eimeria oocysts in chicken feces using flotation recovery with sucrose or saturated saline solution

Takano A, Morinaga D, Teramoto I, Hatabu T, Kido Y, Kaneko A, et al.

Acta Parasitol, 2025 Jan 09;70(1):17.
PMID: 39789311 DOI: 10.1007/s11686-024-00960-6

PURPOSE: Flotation methods are widely used to detect oocysts/cysts of protozoans and eggs of helminths, except trematodes. However, details regarding the concentration and recovery rates of these parasites are poorly understood.
METHODS: Using Eimeria tenella oocysts as a model parasite, the present study evaluated three check points: (1) the proportion of parasites that remain floating in flotation solution (sucrose or saturated saline) during centrifugation, (2) the proportion of oocysts that naturally float after addition of flotation solution after centrifugation, and (3) the rate of recovery on cover slips after completion of the flotation protocol.
RESULTS: After centrifugation in sucrose solution and saturated saline solution, 82.4% and 60.3% of oocysts floated, respectively. After addition of flotation solution after the final centrifugation step, the recovery rates for oocysts that naturally floated again for 30 min in sucrose and saturated saline were 39.2% and 38.2%, respectively. The recovery rate on cover slips as the final step after performing a commonly used flotation method was 36.4% in sucrose solution (the rate for saturated saline solution could not be assessed due to rapid crystallization).
CONCLUSION: Our results suggest that floating oocysts could have become dispersed by the addition of flotation solution, and not all of these oocysts remained floating after an additional 30 min of settling time although collection on cover slips could be effective for accurate recovery.