Abbasiliasi Sahar, Tan Joo Shun, Ibrahim Tengku Azmi Tengku, Ramanan Ramakrishnan Nagasundara, Kadkhodaei Saeid, Mustafa Shuhaimi, Ariff Arbakariya B
1Department of Microbiology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400 Serdang, Selangor Malaysia.
2Bioprocess Technology, School of Industrial Technology, Universiti Sains Malaysia, 11800 Gelugor, Pulau Pinang Malaysia.
J Food Sci Technol. 2018 Apr;55(4):1270-1284. doi: 10.1007/s13197-018-3037-x. Epub 2018 Jan 29.
This paper deliberates the modelling and validation of bacteriocin-like inhibitory substance (BLIS) secretion by Kp10 at different agitation speeds in a stirred tank bioreactor. A range of models namely the re-parameterised logistic, Luedeking-Piret and maintenance energy were assessed to predict the culture performance of the said bacterium. Growth of Kp10 was enhanced with increased agitation speed up to 600 rpm while BLIS secretion was maximum at 400 rpm but decreased at higher agitation speed. Growth of aptly subscribed to the re-parameterised logistic model while BLIS secretion and lactose consumption fitted well with the Luedeking-Piret model. The models revealed a relationship between growth of the bacterium and BLIS secretion. Bacterial growth and BLIS secretion were largely affected by the agitation speed of the stirred tank bioreactor which regulated the oxygen transfer to the culture. BLIS secretion by Kp10 was however enhanced in oxygen-limited culture. The study also assessed BLIS from the perspective of its stability when subjected to factors such as temperature, pH and detergents. Results showed that BLIS produced by this strain was not affected by heat (at 25-100 °C for 20 min and at 121 °C for 15 min), surfactant (Tween 40, 60 and 80 and urea), detergents (up to 1% SDS), organic solvents (50% each of acetone, methanol and ethanol) and stable in a wide range of pH (2-10). The above information are pertinent with reference to commercial applications of this bacterial product in food manufacturing which invariably involve various sterilization processes and subjected to a wide pH range.
本文探讨了在搅拌罐生物反应器中，不同搅拌速度下Kp10分泌类细菌素抑制物质（BLIS）的建模与验证。评估了一系列模型，即重新参数化的逻辑模型、Luedeking-Piret模型和维持能量模型，以预测该细菌的培养性能。Kp10的生长随着搅拌速度增加至600 rpm而增强，而BLIS分泌在400 rpm时达到最大值，但在更高搅拌速度下降低。生长情况恰当地符合重新参数化的逻辑模型，而BLIS分泌和乳糖消耗与Luedeking-Piret模型拟合良好。这些模型揭示了细菌生长与BLIS分泌之间的关系。细菌生长和BLIS分泌在很大程度上受搅拌罐生物反应器搅拌速度的影响，搅拌速度调节了向培养物中的氧气传递。然而，在氧气受限的培养中，Kp10的BLIS分泌会增强。该研究还从温度、pH和洗涤剂等因素作用下的稳定性角度评估了BLIS。结果表明，该菌株产生的BLIS不受热（25 - 100°C下20分钟以及121°C下15分钟）、表面活性剂（吐温40、60和80以及尿素）、洗涤剂（高达1% SDS）、有机溶剂（丙酮、甲醇和乙醇各50%）的影响，并且在广泛的pH范围（2 - 10）内稳定。上述信息对于这种细菌产品在食品制造中的商业应用具有相关性，食品制造中总是涉及各种杀菌过程且会经历广泛的pH范围。
