Purification of glutathione Transferases (GSTs) from identified Rhizospheric bacteria

The glutathione S-Transferase (GST) enzyme plays an important role in cellular detoxification. This multifunctional enzyme is involved in Phase II detoxification pathways that protect cellular macromolecules from being attacked by harmful compound. The study is an attempt to isolate glutathione transferase-expressing bacteria from the rhizospheric soil of selected herbal plants. Screening showed nine positive isolates out of twelve bacterial samples from a large microbial population in our soil collection. Crude extract from strain E1 which was isolated from Piper sarmentosum (Kadok) showed the highest specific activity against 1-chloro-2, 4-dinitrobenzene substrates (5.78 × 10-06 μmol/min/mg). Based on the carbon utilization of E1 assessed using Biolog system, the strain was identified as Comamonas testosterone E1. Glutathione S-transferase purification using GST trap yielded two distinct subunits with molecular weights of 23 and 24 kDa as visualized on 1D SDS-polyacrylamide gel electrophoresis. The purified GST showed reactivity towards 1-chloro-2, 4-dinitrobenzene, 1, 2-dichloro-4-nitrobenzene and ethacrynic acid with specific activity of 0.264 ± 0.038 nmol/min/mg and 0.056 ± 0.002 nmol/min/mg and 10.500 ± 3.130 nmol/min/mg, respectively. However, no activity was detected against p-Nitrobenzyl chloride, Sulfobromophthalein, trans-4-phenyl-3-butene-2-one, hexa-2, 4- dienal, trans-hepta-2, 4-dienal and trans-oct-2-enal in the study

Characterization and identification of Xanthomonas spp. isolated from infected brassicaceae and selection of potential xanthan gum producer

Xanthomonas spp. synthesize a complex exopolysaccharide called xanthan gum, which has significant commercial value. Xanthomonas-infected vegetables exhibiting typical spot symptoms were used in this study. Isolation was done by streaking the sample suspension on the Yeast Malt agar. A colony that resembled Xanthomonas spp. was purified before a simple phenotypic test and identified using BIOLOG and 16 rRNA sequencing. The screening was done based on their performance by fermentation in a shake flask, under controlled conditions. The yield and viscosity of xanthan gum produced from each bacterium were compared to Xanthomonas campestris PV. campestris strain ATCC33913. There were 411 wild types of Xanthomonas spp. successfully isolated and ten strains were selected for xanthan gum evaluation. The results showed, the xanthan production (g/L) varied from (1.57 - 8.24) with the yield of xanthan from 0.64 to 4.71 g/g biomass. Strain C206 produced the highest xanthan gum concentration (8.24±0.20 g/L) compared to others and the control strain, ATCC 33913 (2.27±0.10g/L). The highest yield of xanthan 4.71±0.18 (g/g biomass) was produced by strain C298 followed by strain C279 with 3.88±0.04 (g/g biomass). From our investigation, the production and yield of xanthan gum and the viscosity of the polymers were significantly dependent on the bacterial strain. Based on the stable viscosity and yield of xanthan produced, X. campestris C279 was selected for further studies on product optimization

Soybean as an alternative nutrient medium for Bacillus subtilis growth

Nutrient agar is a commonly used medium for the isolation and growth of a broad range of microorganisms. The feasibility of using soybean as a base medium in the development of alternative growth media was assessed in this study. Nutrient agar was used as a standard guide to evaluating the performance of the formulated soybean agar. Bacillus subtilis was inoculated and allowed to grow on nutrient agar and soybean agar. Their growth was compared within 24 h after inoculation based on the morphology of individual colonies formed on both media and the pattern of bacterial growth. Our results showed that soybean agar had comparable performance to nutrient agar as the morphological characteristics of B. subtilis colonies formed on both media are generally identical in terms of texture, margin, optical properties, colour, elevation, and shape. However, due to the similar appearance of the bacterial colonies and the soybean agar, the colonies formed on the soybean agar were slightly larger than those formed on nutrient agar. In addition, our findings also revealed that agar strips formed the best soybean agar compared to gelatin and agar powder. Ultimately, this study has shown that locally available soybeans and agar strips can be easily formulated as an alternative to commercial nutrient agar and have great potential for bacteriological research

Soybean as an alternative nutrient medium for Bacillus subtilis growth

Nutrient agar is a commonly used medium for the isolation and growth of a broad range of microorganisms. The feasibility of using soybean as a base medium in the development of alternative growth media was assessed in this study. Nutrient agar was used as a standard guide to evaluating the performance of the formulated soybean agar. Bacillus subtilis was inoculated and allowed to grow on nutrient agar and soybean agar. Their growth was compared within 24 h after inoculation based on the morphology of individual colonies formed on both media and the pattern of bacterial growth. Our results showed that soybean agar had comparable performance to nutrient agar as the morphological characteristics of B. subtilis colonies formed on both media are generally identical in terms of texture, margin, optical properties, colour, elevation, and shape. However, due to the similar appearance of the bacterial colonies and the soybean agar, the colonies formed on the soybean agar were slightly larger than those formed on nutrient agar. In addition, our findings also revealed that agar strips formed the best soybean agar compared to gelatin and agar powder. Ultimately, this study has shown that locally available soybeans and agar strips can be easily formulated as an alternative to commercial nutrient agar and have great potential for bacteriological research

Characterization and identification of Xanthomonas spp. isolated from infected brassicaceae and selection of potential xanthan gum producer

Xanthomonas spp. synthesize a complex exopolysaccharide called xanthan gum, which has significant commercial value. Xanthomonas-infected vegetables exhibiting typical spot symptoms were used in this study. Isolation was done by streaking the sample suspension on the Yeast Malt agar. A colony that resembled Xanthomonas spp. was purified before a simple phenotypic test and identified using BIOLOG and 16 rRNA sequencing. The screening was done based on their performance by fermentation in a shake flask, under controlled conditions. The yield and viscosity of xanthan gum produced from each bacterium were compared to Xanthomonas campestris PV. campestris strain ATCC33913. There were 411 wild types of Xanthomonas spp. successfully isolated and ten strains were selected for xanthan gum evaluation. The results showed, the xanthan production (g/L) varied from (1.57 - 8.24) with the yield of xanthan from 0.64 to 4.71 g/g biomass. Strain C206 produced the highest xanthan gum concentration (8.24±0.20 g/L) compared to others and the control strain, ATCC 33913 (2.27±0.10g/L). The highest yield of xanthan 4.71±0.18 (g/g biomass) was produced by strain C298 followed by strain C279 with 3.88±0.04 (g/g biomass). From our investigation, the production and yield of xanthan gum and the viscosity of the polymers were significantly dependent on the bacterial strain. Based on the stable viscosity and yield of xanthan produced, X. campestris C279 was selected for further studies on product optimization

Bioconversion of mixed free fatty acids to poly-3-hydroxyalkanoates by Pseudomonas putida BET001 and modeling of its fermentation in shake flasks

Background: The paper reports on the utilization of palm kernel oil (PKO) as a low cost renewable substrate for medium-chain-length poly-3-hydroxyalkanoates (mcl-PHA) production by Pseudomonas putida BET001. Investigation on the effects of selected key variables on growth, mixed free fatty acids consumption and mcl-PHA production by the bacterial culture in the shaken flask system were carried out along with its kinetic modeling. Results: The biomass production, fatty acids consumption andmcl-PHA production were found favorable when the strain was cultured inmineral medium at pH 6\u20137, 28\ub0C, aeration surface-to-volume ratio of 0.4 7 106m-1, 250 rpm agitation rate for 48 h. Mcl-PHA production by this strain showed mixed growth and non-growth associated components as described by Luedeking\u2013Piret kinetic model. Conclusion: The findings of this study provided add to the literature on key variables in for achieving good microbial growth andmcl-PHA production in shake flasks culture. In addition, suitable kineticmodel to describe cultivation in this system was also presented

Morphometric analysis of craniodental characters of the House Rat, Rattus rattus (Rodentia: Muridae) in Peninsular Malaysia

Rattus rattus which is believed to be native to India is easily found in all continents of the world. With the absence of R. rattus from lineage I and the presence of lineage IV in Southeast Asia, little is known about how rodent morphology varies biogeographically. We evaluate the skull morphometrics in the population of R. rattus in Peninsular Malaysia and examine the intraspecific variation of the skull by assessing 20 craniodental characters of 130 R. rattus specimens. After observing the correlation matrix, highly correlated characters were removed and the remaining 14 craniodental characters were analysed using the conventional morphometrics method via univariate and multivariate statistics. We assessed the impact of age, sex and geographical factors (latitude, longitude and precipitation) on craniodental size. Male and female specimens were analysed separately since statistically significant sexual dimorphism was present. Males showed greater craniodental measurements compared to females. Three distinct age groups (C2, C3 and C4) were visible in the principal component analysis (PCA) and canonical variate analysis (CVA) plots for male and female specimens. Ages C2 and C3 shared similarities in craniodental measurements while C4 showed variability compared to C2 and C3. None of the geographical factors studied showed statistical significance for both male and female R. rattus. The results obtained from this study could potentially be a yardstick to observe if similar variations in craniodental traits are present in R. rattus from other countries in the Southeast Asian region

Review of Coronavirus transmission in urban clusters: Survival in Water and Wastewater Systems

The ongoing Coronavirus Disease 2019 (COVID-19) pandemic has infected over 58 million people and claimed over 1.58 millions deaths globally (as of 11th December 2020) since its first outbreak in Wuhan, China in December 2019. Initially, the numbers of infected patients and death was largely contained in China with 98% of all confirmed infected cases. However, the increased rate of new infected cases outside of China like United States, Italy, and Spain raises questions on the virus characteristics and its routes of transmission. Although the main transmission modes of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are through direct contact and respiratory droplet/aerosol inhalation, current studies stipulate that SARS-CoV-2 RNA is found in sewerage, suggesting the potential transmission of SARS-COV-2 through wastewater systems. This paper seeks to review potential exposure routes of SARS-COV-2 in urban environments, the survival rate of coronaviruses that pose human health risks, and to provide relevant safety recommendations to reduce the impact of ongoing COVID-19 pandemic. There is an urgent need for wastewater effluent and water treatment supply epidemiology surveillance, especially in developing countries with subpar wastewater treatment systems and infrastructure to reduce human and ecological risks to protect populations from infectious diseases outbreak

Inclusion of cricket (Gryllus bimaculatus) meal in African catfish (Clarias gariepinus) feed influences disease resistance

In our present study, we observed the effect of cricket meal (CM) on disease resistance of African catfish. Fish were fed diets containing 350 g kg–1 and 400 g kg–1 of CM and 350 g kg–1 of fishmeal as control. The fish were divided into triplicates treatments of ten fish per replicate, weighed 22.5±0.6 g and fed with experimental diets for 40 days before being challenged against Aeromonas hydrophila. Relative percentage of survival (RPS) was recorded over 12 days post-challenge. White blood cell count, total protein, globulin and lysozyme showed significantly increasing levels in those fed with cricket meal diet compared to the control group. Mortalities at 12-day post-challenge significantly decreased to 30% (RPS: 66.7%) and 27% (RPS: 70%) for 35% and 40% CM respectively compared to 90% mortality in control group. Intestines and liver tissues of infected fish were dissected for pathogenic confirmation. The intestines of control diet showed the highest bacterial load (58.2×107 cfu g–1) compared to CM diets. The current study indicates that dietary CM could enhance the innate immune system and disease resistance of African catfish

パームオイル産業のエネルギー管理に基づくパームバイオマスからの生物的変換による有用物質製造

九州工業大学博士学位論文（要旨） 学位記番号:生工博甲第147号 学位授与年月日:平成22年9月30