Paisan Kanthang

Quantitative analysis of time-series fluorescence microscopy using a spot tracking method: application to Min protein dynamics

The dynamics of MinD protein has been recognized as playing an important role in the accurate positioning of the septum during cell division. In this work, spot tracking technique (STT) was applied to track the motion and quantitatively characterize the dynamic behavior of green fluorescent protein-labeled MinD (GFP-MinD) in an Escherichia coli system. We investigated MinD dynamics on the level of particle ensemble or cluster focusing on the position and motion of the maximum in the spatial distribution of MinD proteins. The main results are twofold: (i) a demonstration of how STT could be an acceptable tool for MinD dynamics studies; and (ii) quantitative findings with parametric and non-parametric analyses. Specifically, experimental data monitored from the dividing E. coli cells (typically 4.98 ± 0.75 µm in length) has demonstrated a fast oscillation of the MinD protein between the two poles, with an average period of 54.6 ± 8.6 s. Observations of the oscillating trajectory and velocity show a trapping or localized behavior of MinD around the polar zone, with average localization velocity of 0.29 ± 0.06 µm/s; and flight switching was observed at the pole-to-pole leading edge, with an average switching velocity of 2.95 ± 0.31 µm/s. Subdiffusive motion of MinD proteins at the polar zone was found and investigated with the dynamic exponent, α of 0.34 ± 0.16. To compare with the Gaussian-based analysis, non-parametric statistical analysis and noise consideration were also performed.

The Study and Screening of Bacteria for Silver Nanoparticle Biosynthesis

The silver refinery is very important for west management in the jewelry industry. In this work, we proposed the alternative of silver refinery process by using microorganism pathway. We focused on the isolation of microorganism which was found from manufacturing process and forming in gems and jewelry industry. Results showed that the initial silver refinery microorganism performed only in terms of Pseudomonas genus especially in AgNO3 solution. In contrast, Bacillus genus was not clearly effective silver refinery. These results could be the basis information to establish and develop system for silver refinery and/or silver quality improvement with biological process in future.

The Relationships among Microorganisms in Paddy Soil of Rice Varieties at Sanamchaikate, Chachoengsao

The research was conducted to understand the diversity of microbial communities in the rice cultivars KDM 105 in the rice fields at Sanamchaikate, Chachoengsao Province. The culturing bacterial community in paddy soil before planting, during the planting and sowing of rice, and after rice collection as well as isolation of free nitrogen fixing bacteria under aerobic and anaerobic conditions were identified by molecular comparision of 16S small subunit rRNA genes as well as species diversity and their richness by Most Probable Number (MPN) method. Culturable bacterial isolates in the soil around the roots of rice varieties were determined for their physical appearances on the solid culture (Plate culturing method) and the microscopic observation under light microscope. It was found that bacteria in the paddy soil complemented with organic fertilizers and no pesticide application for over five years had a pH range from 5.2 to 5.5 cultivated jasmine rice, 8-9 log Units of free N2-fixing bacteria near the roots compared with those in other area having 4-5 log Units. Most of them were identified to be Pseudomonas sp. Microbacterium sp. Bacillus sp. Stenotrophomonas sp. and Burkholderia sp., by homology comparison of 16S rDNA gene at 98, 97, 99, 99.5, and 99%, respectively. This research revealed the recognizable complex and change in soil bacteria presented in paddy ecosystem. In any critical change of to the soil, the study of microbial diversity, compositions and their richness can be further useful for indicating proper soil management.

Image Enhancement for Characterization of MinD Protein Oscillation in Escherichia coli

MinD proteins play important roles during cell division process. These proteins show significant characteristics of periodic pole-to-pole propagation along the cell length. The characterizations of these protein behaviors are required to be determined accurately. Usually by using a fluorescent technique, visual motion of proteins in the cell could possibly be made and observed through a CCD. Due to the nature of low intensity of these proteins, the images obtained from the CCD camera were required to subject to noise interference and as a result digital image processing was also required. In this paper, several techniques were tried to facilitated improve the image quality. From our finding, the fluorescent technique could affect the intensity fading of the protein detected, but not to the numbers of the proteins in the cell.

The Flour Processing Machine for Musa sapientum Linn

Banana flour is one of the main commercial products that could be incorporated into other food products. However, the current processing of banana flour production is not only incompatible to traditional village level; but also difficult to manage for the quality control. In this work, we constructed the low cost banana flour processing machines including dryer and pounder. We also tested our machines by using three conditions of banana cleaning such as salt, vinegar and red lime. The dehydrate banana and flour were characterized by CIE-Lab and particle size analysis. After pneumatic drying at 70oC and 3 hr, we found that vinegar had the whiteness value greater than other conditions. We also found that the flour obtained from vinegar presented the smallest diameter which was approximately 0.017 mm. This particle size diameter corresponds to mesh size No. 20 in ASTM E11:01 standard. These results showed that the characterization protocol of banana flour used to grading the dehydrate banana and flour. Therefore, with our project obtained can be such a high potential approach that can be developed product in household, community in terms of commercial production or community enterprise.

Microbial Comparison in Synthesizing Gold Nanoparticles for Harvesting Gold in Wastewater System

Since the green chemistry strategy of the use of biological process is well known for its safe, easy, nontoxic, biocompatible and especially environmental friendly to all users. Recently, more nanomaterials synthesized by the uses of plants and/ or microorganisms are applied in many areas such as electronics, nanotechnology. Especially they are used to synthesize novel materials with unique properties and purposes. In this study, the researchers aimed to isolate microorganisms with the capability in gold nanoparticles (AuNPs) synthesis from the sources that are from gold management process such as leaching and washing process in gold/ jewelry carving factory. Three isolated genera composed of bacteria, yeasts, fungi synthesizing intracellular AuNOs were obtained and characterized for their species by PCR amplification of rDNA genes and sequence analysis and comparisons. They were Pseudomonas sp., Verticillium sp., Aspergillus sp., and Saccharomyces sp. The factors including pH, temperature, reducing agents, duration of AuNP formation were determined. The predominantly extracellular gold formation as a major criterion for synthesis of AuNPs was also chosen. The obtained isolates can be certain potential in future practical application in harvesting AuNPs from the waste water in most gold carving factory.

Pesticides Contaminated in Rice Paddy Soil Affecting on Cultivated Microorganism Community

It has been known for the diversified microbes living in the soil are basic indicators of changes in the ecosystem especially in paddy soil. The effects of continuous application of pesticides in rice field are widely discussed but still disregarded due to unclear and underestimated by the users and the chemicals also need time to accumulate and slowly affect the environment and health. The objective of this research was to understand the effects of pesticides on microorganism community in rice field. Both the numbers and the types of useful soil microorganisms including nitrogen fixing and common habituated microorganisms were compared in between using and not using chemical pesticides samples. The results showed that productivity of cultured microorganisms in the paddy applied with pesticides has dropped only slightly (approximately 9% reduction), however, more spore-forming Gram positive bacteria were detected. Additionally, increases in common microorganisms in the soil at a depth below than 20-50 cm were observed that could possibly be because of less pesticide availability there comparing to the surface of paddy soil. Although the changes in numbers and types of culturable microbes in the paddy soil contaminated with chemical pesticides were less than the actual diversity of species and cultivars, this study could help primarily indicate the adverse effects of the use of chemical pesticides. They thus interfered the ecological balance of the number and type of microorganisms especially at the site doing pesticide application.