Institute of Molecular Biosciences, Massey University, Palmerston North, New Zealand.
J Appl Microbiol. 2009 Sep;107(3):1012-8. doi: 10.1111/j.1365-2672.2009.04282.x. Epub 2009 Mar 25.
To examine the rate and the extent of spore formation in Anoxybacillus flavithermus biofilms and to test the effect of one key variable - temperature - on spore formation.
A continuous flow laboratory reactor was used to grow biofilms of the typical dairy thermophile A. flavithermus (strain CM) in skim milk. The reactor was inoculated with either a washed culture or a spore suspension of A. flavithermus CM, and was run over an 8.5 h period at three different temperatures of 48, 55 and 60 degrees C. Change in impedance was used to determine the cell numbers in the milk and on the surface of the stainless steel reactor tubes. The biofilm developed at all three temperatures within 6-8 h. Spores formed at 55 and 60 degrees C and amounted to approx. 10-50% of the biofilm. No spores formed at 48 degrees C.
The results suggest that both biofilm formation and spore formation of A. flavithermus can occur very rapidly and simultaneously. In addition, temperature variation has a considerable effect on the formation of spores.
This information will provide direction for developing improved ways in which to manipulate conditions in milk powder manufacturing plants to control biofilms and spores of A. flavithermus.
研究黄嗜热杆菌生物膜中的孢子形成率和形成程度，并测试一个关键变量-温度-对孢子形成的影响。
使用连续流动实验室反应器在脱脂乳中培养典型的乳制品嗜热菌黄嗜热杆菌（CM 株）的生物膜。反应器接种了黄嗜热杆菌 CM 的洗菌液或孢子悬浮液，并在 48、55 和 60°C 三个不同温度下运行 8.5 小时。阻抗变化用于确定牛奶中和不锈钢反应器管表面的细胞数量。在所有三个温度下，生物膜在 6-8 小时内形成。在 55 和 60°C 下形成孢子，约占生物膜的 10-50%。在 48°C 下未形成孢子。
结果表明，黄嗜热杆菌的生物膜形成和孢子形成都可以非常迅速且同时发生。此外，温度变化对孢子形成有很大影响。
这些信息将为改进控制奶粉生产厂中黄嗜热杆菌生物膜和孢子的方法提供方向。
