IMPACT OF SINGLE AND TWO-PHASE DISSOLVED OXYGEN TENSION CONTROL ON Bacillus thuringiensis CULTIVATION AND δ-ENDOTOXIN PRODUCTION

https://doi.org/10.55230/mabjournal.v50i1.14

Authors

  • MOHAMED MAZMIRA MOHD MASRI Entomology and Integrated Pest Management Unit, Biology and Sustainability Research Division, Malaysian Palm Oil Board, 43000 Kajang, Selangor, Malaysia
  • MOHD SHAWAL THAKIB MAIDIN Entomology and Integrated Pest Management Unit, Biology and Sustainability Research Division, Malaysian Palm Oil Board, 43000 Kajang, Selangor, Malaysia
  • ARBAKARIYA BIN ARIFF Department of Bioprocess Technology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia

Keywords:

Aeration strategy, dissolve oxygen tension, Bacillus thuringiensis, δ-endotoxin, high sporulation

Abstract

Constant δ-endotoxin production is crucial in Bacillus thuringiensis 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 B. thuringiensis was investigated using a 5-L stirred tank bioreactor. Single-phase DOT control recorded low spore count (<5.0 × 1011 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 δ-endotoxin formed as early as 8 hr of cultivation. A high maximum specific growth rate, μmax (>0.1 h-1) was also essential in ensuring δ-endotoxin production. High cell count obtained in cultivation with DOT level of 80% saturation during active growth was concurrent with high cell count, high μmax, 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 B. thuringiensis cultivation performance.

Downloads

Download data is not yet available.

Metrics

Metrics Loading ...

Published

30-03-2021

How to Cite

MOHD MASRI, M. M., MAIDIN, M. S. T., & BIN ARIFF, A. (2021). IMPACT OF SINGLE AND TWO-PHASE DISSOLVED OXYGEN TENSION CONTROL ON Bacillus thuringiensis CULTIVATION AND δ-ENDOTOXIN PRODUCTION. Malaysian Applied Biology, 50(1), 73–84. https://doi.org/10.55230/mabjournal.v50i1.14

Issue

Section

Research Articles