Optimization of Biological Substance Production from Bacillus subtilis Strain OK1101 in A 10 L Stirred Fermenter
Keywords:
Bacillus sp., biological substance, production, weedy riceAbstract
Bacillus subtilis strain OK1101, isolated from soil, has been reported to produce amylase and cellulase enzymes and exhibits potential for inhibiting weedy rice germination by more than 50% at the flask scale. This study aimed to determine optimal conditions and develop a biocontrol formulation from B. subtilis OK1101 for managing weedy rice in paddy fields. The effects of medium composition and physical parameters were investigated using a 10 L bioreactor. Among the tested media, formulation T supported the highest growth and biomass production, yielding 3.01±0.19 g/L, with viable cell counts of 7.91±0.02 log CFU/ml and an optical density at 600 nm of 2.28±0.11. Furthermore, cultivation at an agitation speed of 200 rpm combined with an aeration rate of 0.07 vvm (volume of air per volume of medium per minute) was found to be optimal for microbial cell production. Under these conditions, the maximum biomass yield reached 11.97±0.76 g/L, with viable cell counts of 8.93±0.17 log CFU/ml and optical density at 600 nm of 0.64±0.13. These findings demonstrate that B. subtilis OK1101 can be efficiently cultivated under controlled bioreactor conditions, achieving enhanced production of biomass, enzymes, and biological substance when using an aeration rate of 0.07 vvm and agitation speed of 200 rpm.
Downloads
References
DOA. (2021, April 7). Biological control agents for pest management. Department of Agriculture, Ministry of Agriculture and Cooperatives, Thailand. https://www.doa.go.th/share/attachment.php?aid=3005
Martinez-Mendoza, E. K., Mena-Violante, H. G., Mendez-Inocencio, C., Oyoque-Salcedo, G., Cortez-Madrigal, H., Olalde-Portugal, V., and Angoa-Pérez, M. V. (2012). Effects of Bacillus subtilis extracts on weed seed germination of Sorghum halepense and Amaranthus hybridus. African Journal of Microbiology Research, 6(9), 1887-1892.
Janaki, M., Sivadasan Unni, P. K., Stanley-Raja, V., Senthil-Nathan, S., Almutairi, B. O., and Abdel-Megeed, A. (2024). Biocontrol effect of Bacillus subtilis against Cnaphalocrocis medinalis (Guenèe) (Lepidoptera: Pyralidae): A sustainable approach to rice pest management. Agronomy, 14(2), Article 310.
Muis, A. (2006). Biomass production and formulation of Bacillus subtilis for biological control. Indonesian journal of agricultural science, 7(2), 51-56.
Sae-lee, N., Makme, T., and Iampoom, S. (2014). Microbial management of weedy rice in paddy rice fields [Unpublished manuscript]. Department of Microbiology, Srinakharinwirot University.
Bunyawattana, P. (2020). Optimization conditions for Bacillus subtilis strain OK1101 production for the elimination of weedy rice [Unpublished manuscript]. Department of Microbiology, Srinakharinwirot University.
Nadir, S., Xiong, H. B., Zhu, Q., Zhang, X. L., Xu, H. Y., Li, J., Dongchen, W., Henry, D., Guo, X. Q., Khan, S., Suh, H. S., Lee, D. S., and Chen, L. J. (2017). Weedy rice in sustainable rice production. A review. Agronomy for Sustainable Development, 37, 1-14.
Roma-Burgos, N., San Sudo, M. P., Olsen, K. M., Werle, I., and Song, B. K. (2021). Weedy rice (Oryza spp.): What’s in a name?. Weed Science, 69(5), 505-513.
Maneechote, C., Samanwong, S., Suwanketnikom, R., and Jamjod, S. (2006). Chemical control of weedy rice in pre-germinated wet seeded rice in Thailand. Fifteenth Australian Weeds Conference. pp. 317-319.
Cao, Q., Lu, B. R., Xia, H. U. I., Rong, J., Sala, F., Spada, A., and Grassi, F. (2006). Genetic diversity and origin of weedy rice (Oryza sativa f. spontanea) populations found in north-eastern China revealed by simple sequence repeat (SSR) markers. Annals of botany, 98(6), 1241-1252.
Koim-Puchowska, B., Kłosowski, G., Dróżdż-Afelt, J. M., Mikulski, D., and Zielińska, A. (2021). Influence of the medium composition and the culture conditions on surfactin biosynthesis by a native Bacillus subtilis natto BS19 strain. Molecules, 26(10), Article 2985.
Kokkonen, P., Beier, A., Mazurenko, S., Damborsky, J., Bednar, D., and Prokop, Z. (2021). Substrate inhibition by the blockage of product release and its control by tunnel engineering. RSC Chemical Biology, 2(2), 645-655.
Khumrangsee, K., Charoenrat, T., Suvanasingha, N., and Chittapun, S. (2021). Effect of agitation and aeration on the growth of Aurantiochytrium sp. FIKU018 fed batch cultured in bioreactor. Wichcha Journal Nakhon Si Thammarat Rajabhat University, 40(1), 135-149.
Henshaw, E., and Wakil, S. M. (2019). Effect of agitation speed and incubation time on amylase production by Bacillus species isolated from malted and fermented Maize (Zea mays). Microbiology Research Journal International, 27(3), 1-7.
You, J. H., Jeong, H. J., Park, S. A., Eom, S. H., Kang, H. C., and Ok, J. H. (2024). Effects of aeration and centrifugation conditions on omega-3 fatty acid production by the mixotrophic dinoflagellate Gymnodinium smaydae in a semi-continuous cultivation system on a pilot scale. Algae, 39(2), 109-127.
Downloads
Published
How to Cite
Issue
Section
License
Copyright (c) 2025 Srinakharinwirot University Journal of Sciences and Technology

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
Srinakharinwirot University Journal of Sciences and Technology is licensed Under a Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International (CC-BY-NC-ND 4.0) License, Unless Otherwise Stated. Please Read Journal Policies Page for More Information on Open Access, Copyright and Permissions.