Thimmaraju R, Bhagyalakshmi N, Narayan M S, Ravishankar G A
Plant Cell Biotechnology Department, Central Food Technological Research Institute, Mysore 570013, India.
Biotechnol Prog. 2003 Jul-Aug;19(4):1274-82. doi: 10.1021/bp0201399.
Hairy root cultures of red beet, Beta vulgaris L., were permeabilized under the functions of food-grade chemical and biological agents cetyl trimethylammonium bromide (CTAB), Triton X-100, Tween-80, Lactobacillus helveticus, Saccharomyces cereviseae, and Candida utilis, as well as cell fractions of L. helveticus, for the recovery of betalaines with or without oxygen stress. Tween-80 (0.15%), Triton X-100 (0.2%), and CTAB (0.05%), in combination with oxygen stress, released 45%, 70%, and 90% pigment into the medium, respectively, with significantly lesser levels in agitated cultures receiving similar treatments. The release was rapid (1 h) in CTAB treatment with a much slower release in Tween-80. CTAB (0.002%) was found to be also useful in effluxing betalaines (80%) from hairy roots grown in a bubble column reactor. Viability of permeabilized hairy roots, tested on agar medium, was not affected by any level of CTAB treatment and was significantly retarded at higher levels of Triton X-100 and Tween-80. An altogether new approach of pigment release using biological agents such as live cells of food-grade microbes was used where C. utilis, L. helveticus, and S. cereviseae released 60%, 85%, and 54% betalaines, respectively, in 24 h, though lower level treatments also released similar levels of pigment by 48 h. Dried whole cell powder of L. helveticus, its total insoluble carbohydrate, and free lipid fractions released 10%, 0%, and 85% pigment, respectively. An extended study with a bubble column reactor using the free lipid fraction of L. helveticus showed 50% and 84% pigment release in 8 and 12 h, respectively, exhibiting good viability when plated on agar medium. Even in the bioreactor, replenishment of medium 8 h after treatment with free lipid of L. helveticus allowed regrowth of hairy roots. The high level of pigment release recorded here, using CTAB or lipid of L. helveticus, appears useful for developing processes for in situ recovery of betalaines. The live microbes, applicable only for batch cultures, are expected to impart improved sensory/nutraceutical effects to the recovered pigment and hence may add value to the product receiving the red beet pigment thus produced.
在食品级化学和生物制剂十六烷基三甲基溴化铵（CTAB）、Triton X - 100、吐温80、瑞士乳杆菌、酿酒酵母和产朊假丝酵母以及瑞士乳杆菌的细胞组分的作用下，对红甜菜（Beta vulgaris L.）的毛状根培养物进行透化处理，以在有氧或无氧胁迫下回收甜菜碱。吐温80（0.15%）、Triton X - 100（0.2%）和CTAB（0.05%）与氧胁迫相结合，分别将45%、70%和90%的色素释放到培养基中，在接受类似处理的搅拌培养物中色素释放水平显著较低。CTAB处理时色素释放迅速（1小时），吐温80处理时释放则慢得多。发现CTAB（0.002%）也可用于从气泡柱反应器中生长的毛状根中流出甜菜碱（80%）。在琼脂培养基上测试，透化毛状根的活力不受任何水平CTAB处理的影响，但在较高水平的Triton X - 100和吐温80处理下活力显著降低。采用了一种全新的使用食品级微生物活细胞等生物制剂释放色素的方法，其中产朊假丝酵母、瑞士乳杆菌和酿酒酵母分别在24小时内释放了60%、85%和54%的甜菜碱，不过较低水平处理在48小时时也释放了类似水平的色素。瑞士乳杆菌的干燥全细胞粉末、其总不溶性碳水化合物和游离脂质组分分别释放了10%、0%和85%的色素。使用瑞士乳杆菌游离脂质组分在气泡柱反应器中进行的扩展研究表明，分别在8小时和12小时内色素释放率为50%和84%，接种到琼脂培养基上时显示出良好的活力。即使在生物反应器中，用瑞士乳杆菌游离脂质处理8小时后补充培养基，毛状根仍能再生。此处记录的使用CTAB或瑞士乳杆菌脂质实现的高色素释放水平，似乎有助于开发甜菜碱原位回收工艺。这些活微生物仅适用于分批培养，预计会给回收的色素带来改善的感官/营养保健效果，因此可能会为由此生产的红甜菜色素产品增值。
