Wilson J A, Postlethwaite J, Pearce J D, Leach G, Lye G J, Shamlou P Ayazi
Advanced Centre for Biochemical Engineering, Department of Biochemical Engineering, University College London, Torrington Place, London WC1E 7JE, United Kingdom.
Biotechnol Bioeng. 2003 Jul 20;83(2):235-40. doi: 10.1002/bit.10665.
New experimental data are reported that demonstrate the use of a novel vibrating membrane filter (VMF) for the combined recovery and concentration of two species of nematodes, S. feltiae and P. hermaphrodita, from mature liquid fermentation cultures. The disk membrane module had a working surface area of 0.2 m(2) and was operated at a constant flow rate of 0.2 m(3) h(-1). The recovery of the viable nematodes from the spent media and nonviable nematodes was assisted by an independently imposed oscillatory motion of the disk assembly, which produced an intense shear field at the membrane surface with calculated mean values on the order of 10(4) s(-1). Adult (nonviable) nematodes in the fermentation culture were preferentially dissolved in a detergent (sodium dodecylsulfate) and successfully separated from the juveniles using the VMF equipment. Permeate fluxes on the order of 15 to 30 L/m(2/)h were achieved for an operating transmembrane pressure of 800 mbar. Industrial-scale liquid fermentation for the manufacture of nematodes as biopesticides produces the viable nematode life stages in low-concentration suspension containing large quantities of spent media and other waste material. The VMF equipment provided a flexible operation for separation, cleaning, and concentration of viable nematodes from the fermentation broths.
报道了新的实验数据，这些数据证明了一种新型振动膜过滤器（VMF）可用于从成熟的液体发酵培养物中联合回收和浓缩两种线虫，即斯氏线虫（S. feltiae）和雌雄同体拟丽突线虫（P. hermaphrodita）。盘式膜组件的工作表面积为0.2平方米，以0.2立方米/小时的恒定流速运行。通过独立施加的盘组件振荡运动辅助从废培养基中回收活线虫以及去除死线虫，该振荡运动在膜表面产生了强烈的剪切场，计算得出的平均值约为10⁴秒⁻¹。发酵培养物中的成年（死）线虫优先溶解在洗涤剂（十二烷基硫酸钠）中，并使用VMF设备成功地与幼虫分离。在800毫巴的操作跨膜压力下，渗透通量达到了15至30升/平方米/小时的量级。用于制造作为生物农药的线虫的工业规模液体发酵，会在含有大量废培养基和其他废料的低浓度悬浮液中产生活线虫的不同生命阶段。VMF设备为从发酵液中分离、清洗和浓缩活线虫提供了灵活的操作方式。
