Browsing by Author "Vassanasak Limkhuansuwan"

Now showing 1 - 3 of 3
  • Default Image
    Item
    Effects of Nutrient Supplement and Chitosan on Microbial Population Change in Up-Flow-Anaerobic-Sludge-Blanket Reactor during Biogas Production
    (Research and Development Institute Suan Dusit University, 2021) Rungroj Piyaphanuwat; Srisuda Samaimai; Vassanasak Limkhuansuwan; V. Limkhuansuwan; Faculty of Science and Technology, Suan Dusit University, Bangkok, 10700, Thailand; email: vassanasak_lim@dusit.ac.th
    The objective of this research was to study the effects of nutrient supplement and chitosan on microbial change in an up-flow-anaerobic-sludge-blanket (UASB) reactor during biogas production. Three UASB reactors were operational in this study. All reactors were operated by feeding dilute stillage with chemical oxygen demand (COD) concentration at 10,000 mg/L and 9 days of hydraulic retention time (HRT) under anaerobic conditions. Reactor 2 and reactor 3 were supplemented with nutrient supplement and chitosan, respectively. The results of the environment and pH values of all UASB reactors showed similar conditions with total volatile acid/ alkalinity (TVA/Alk) values of 0.27-0.31. The COD removal efficiency of reactor 1 (stillage), 2 (stillage and nutrient supplement) and 3 (stillage and chitosan) showed about 79%, 84% and 87%, respectively. In addition, it was found that the UASB reactors supplemented with nutrient supplement or chitosan produced higher levels of biogas than those without additives. The 16S rRNA technique by PCR reaction showed that the dominant archaea in the final fermentation of all UASB reactors and in inoculum sample were hydrogenotrophic (genus Methanobacterium) and acetotrophic methanogens (genus Methanosaeta). The methanogens population in the reactor supplemented with chitosan (18.11%) produced more biogas than the ones in the reactor supplemented with nutrient supplement (14.44%) and in the control reactor (15.95%). © 2021, Research and Development Institute Suan Dusit University. All rights reserved.
  • Default Image
    Item
    Effects of Nutrient Supplement and Chitosan on Microbial Population Change in Up-Flow-Anaerobic-Sludge-Blanket Reactor during Biogas Production
    (Graphicsite, 2023-09-26) Rungroj Piyaphanuwat; Srisuda Samaimai; Vassanasak Limkhuansuwan
    The objective of this research was to study the effects of nutrient supplement and chitosan on microbial change in an up-flow-anaerobic-sludge-blanket (UASB) reactor during biogas production. Three UASB reactors were operational in this study. All reactors were operated by feeding dilute stillage with chemical oxygen demand (COD) concentration at 10,000 mg/L and 9 days of hydraulic retention time (HRT) under anaerobic conditions. Reactor 2 and reactor 3 were supplemented with nutrient supplement and chitosan, respectively. The results of the environment and pH values of all UASB reactors showed similar conditions with total volatile acid/ alkalinity (TVA/Alk) values of 0.27-0.31. The COD removal efficiency of reactor 1 (stillage), 2 (stillage and nutrient supplement) and 3 (stillage and chitosan) showed about 79%, 84% and 87%, respectively. In addition, it was found that the UASB reactors supplemented with nutrient supplement or chitosan produced higher levels of biogas than those without additives. The 16S rRNA technique by PCR reaction showed that the dominant archaea in the final fermentation of all UASB reactors and in inoculum sample were hydrogenotrophic (genus Methanobacterium) and acetotrophic methanogens (genus Methanosaeta). The methanogens population in the reactor supplemented with chitosan (18.11%) produced more biogas than the ones in the reactor supplemented with nutrient supplement (14.44%) and in the control reactor (15.95%).
  • Default Image
    Item
    Selection of Potential Bacteria in Termite Nest and Gut for Sustainable Agriculture
    (Walailak University, 2024) Phanukit Kunhachan; Wandee Sirithana; Orapin Komutiban; Vassanasak Limkhuansuwan; Phanchai Menchai; Chanaporn Trakunjae; Thanasak Lomthong; Kriangsak Ruchusatsawat; Srisuda Samaimai; S. Samaimai; Faculty of Science and Technology, Suan Dusit University, Bangkok, 10700, Thailand; email: srisuda_sam@dusit.ac.th
    In this study, bacteria with the best abilities in cellulose degradation, siderophore production, phosphate solubility, and Pythium parasitica inhibition were selected from termite nests and guts. The isolate BTNASP 5-2, BTPK 5-3 and BTNA 5-1 from termite guts exhibited highest in siderophore production index (SPI) (4.16 ± 0.21), phosphate solubilizing index (PSI) (2.10 ± 0.14) and percentage inhibition of radial growth (PIRG) (67.07 ± 4.02 %), respectively. The BGNACMC 4-3 isolated from termite nest gave the highest cellulolytic index (CI) of 5.17 ± 0.24. Bacterial classification was performed using 16s rRNA gene sequencing. The isolates BTPK 5-3, BGNACMC 4-3 and BTNA 5-1 were found closely related to Bacillus cereus, whereas the bacterial isolate BTNASP 5-2 was closely related to Bacillus subtilis. It is also suggested that the Bacillus cereus exhibited a variety of biological activities, denoting the highest cellulase, phosphate-solubilizing and antifungal activities, while Bacillus subtilis produced only a siderophore. The results obtained suggest that the bacteria selected will be used to develop bio-compost to promote plant growth, leading to sustainable farming. © 2024, Walailak University. All rights reserved.