@article{MOHD MASRI_MAIDIN_BIN ARIFF_2021, title={IMPACT OF SINGLE AND TWO-PHASE DISSOLVED OXYGEN TENSION CONTROL ON Bacillus thuringiensis CULTIVATION AND δ-ENDOTOXIN PRODUCTION}, volume={50}, url={https://jms.mabjournal.com/index.php/mab/article/view/14}, DOI={10.55230/mabjournal.v50i1.14}, abstractNote={<p><span class="fontstyle0">Constant </span><span class="fontstyle2">δ</span><span class="fontstyle0">-endotoxin production is crucial in </span><em><span class="fontstyle3">Bacillus thuringiensis </span></em><span class="fontstyle0">cultivation with aeration strategy playing a significant role in the process. In this study, the impact of DOT control strategies on the cultivation performance of </span><em><span class="fontstyle3">B. thuringiensis </span></em><span class="fontstyle0">was investigated using a 5-L stirred tank bioreactor. Single-phase DOT control recorded low spore count (<5.0 × 10</span><span class="fontstyle0">11 </span><span class="fontstyle0">spore/mL) and low percentage of sporulation (<45%). Two-stage DOT control cultivation with DOT at 80% during the active growth phase, followed by a switch to 60% or 40% at mid-exponential growth phase contributed to enhanced sporulation (>60%), high maximum cell count (1.5 cfu/mL) with </span><span class="fontstyle2">δ</span><span class="fontstyle0">-endotoxin formed as early as 8 hr of cultivation. A high maximum specific growth rate, μ</span><span class="fontstyle0">max </span><span class="fontstyle0">(>0.1 h</span><span class="fontstyle0">-1</span><span class="fontstyle0">) was also essential in ensuring </span><span class="fontstyle2">δ</span><span class="fontstyle0">-endotoxin production. High cell count obtained in cultivation with DOT level of 80% saturation during active growth was concurrent with high cell count, high μ</span><span class="fontstyle0">max</span><span class="fontstyle0">, fast generation time, high OUR, high CER value, and high respiratory quotient (RQ) value. During the two-phase DOT control cultivation, low RQ values were reported. The result showed that the exhaust gas data could be used to monitor </span><em><span class="fontstyle3">B. thuringiensis </span></em><span class="fontstyle0">cultivation performance.</span> </p>}, number={1}, journal={Malaysian Applied Biology}, author={MOHD MASRI, MOHAMED MAZMIRA and MAIDIN, MOHD SHAWAL THAKIB and BIN ARIFF, ARBAKARIYA}, year={2021}, month={Mar.}, pages={73–84} }